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Is istiratumab effective for pancreatic cancer? | No. In clinical trial, istiratumab failed to improve efficacy of standard of care for pancreatic cancer. | BACKGROUND: Preclinical data suggest that dual blockade of the insulin-like
growth factor-1 receptor (IGF-1R) and HER3 pathways has superior activity to
IGF-1R blockade alone in pancreatic ductal adenocarcinoma (PDAC). We tested
whether istiratumab, an IGF-1R- and ErbB3-bispecific antibody, can enhance the
efficacy of standard of care (SOC) chemotherapy in patients with metastatic PDAC
selected for high IGF-1 serum levels.
PATIENTS AND METHODS: CARRIE was an international, randomized, double-blind,
placebo-controlled phase II study for patients with previously untreated
metastatic PDAC. In part 1, 10 patients were evaluated for pharmacokinetics and
safety. In part 2, patients with high free serum IGF-1 levels were randomized 1
: 1 to receive either istiratumab [2.8 g intravenously (i.v.) every 2 weeks] or
placebo combined with gemcitabine/nab-paclitaxel at approved dose schedule. The
co-primary endpoints were progression-free survival (PFS) in patients with high
IGF-1 levels and PFS in patients with both high serum IGF-1 levels and heregulin
(HRG)+ tumors. Key secondary endpoints were overall survival (OS), objective
response rate (ORR) by RECIST v.1.1, and adverse events (AEs) rate.
RESULTS: A total of 317 patients were screened, with 88 patients randomized in
part 2 (experimental arm n = 43; control n = 45). In the high IGF-1 cohort,
median PFS was 3.6 and 7.3 months in the experimental versus control arms,
respectively [hazard ratio (HR) = 1.88, P = 0.027]. In the high IGF-1/HRG+
subgroup (n = 44), median PFS was 4.1 and 7.3 months, respectively (HR = 1.39,
P = 0.42). Median OS and ORR for the overall population were similar between two
arms. No significant difference in serious or grade ≥3 AEs was observed,
although low-grade AEs leading to early discontinuation were higher in the
experimental (39.5%) versus control arm (24.4%).
CONCLUSIONS: Istiratumab failed to improve the efficacy of SOC chemotherapy in
this patient setting. High serum IGF-1 levels did not appear to be an adverse
prognostic factor when compared with non-biomarker-selected historic controls.
CLINICAL TRIAL REGISTRATION NUMBERS: ClinicalTrials.gov: NCT02399137; EUDRA CT:
2014-004572-34. |
What is the human proteoform project? | Top-down proteomics is emerging as a preferred approach to investigate biological systems, with objectives ranging from the detailed assessment of a single protein therapeutic, to the complete characterization of every possible protein including their modifications, which define the human proteoform. | Proteins are domit executors of living processes. Compared to genetic
variations, changes in the molecular structure and state of a protein (i.e.
proteoforms) are more directly related to pathological changes in diseases.
Characterizing proteoforms involves identifying and locating primary structure
alterations (PSAs) in proteoforms, which is of practical importance for the
advancement of the medical profession. With the development of mass spectrometry
(MS) technology, the characterization of proteoforms based on top-down MS
technology has become possible. This type of method is relatively new and faces
many challenges. Since the proteoform identification is the most important
process in characterizing proteoforms, we comprehensively review the existing
proteoform identification methods in this study. Before identifying proteoforms,
the spectra need to be preprocessed, and protein sequence databases can be
filtered to speed up the identification. Therefore, we also summarize some
popular deconvolution algorithms, various filtering algorithms for improving the
proteoform identification performance and various scoring methods for localizing
proteoforms. Moreover, commonly used methods were evaluated and compared in this
review. We believe our review could help researchers better understand the
current state of the development in this field and design new efficient
algorithms for the proteoform characterization. Proteoforms are the workhorses of the cell, and subtle differences between their
amino acid sequences or post-translational modifications (PTMs) can change their
biological function. To most effectively identify and quantify proteoforms in
genetically diverse samples by mass spectrometry (MS), it is advantageous to
search the MS data against a sample-specific protein database that is tailored
to the sample being analyzed, in that it contains the correct amino acid
sequences and relevant PTMs for that sample. To this end, we have developed
Spritz (https://smith-chem-wisc.github.io/Spritz/), an open-source software tool
for generating protein databases annotated with sequence variations and PTMs. We
provide a simple graphical user interface for Windows and scripts that can be
run on any operating system. Spritz automatically sets up and executes
approximately 20 tools, which enable the construction of a proteogenomic
database from only raw RNA sequencing data. Sequence variations that are
discovered in RNA sequencing data upon comparison to the Ensembl reference
genome are annotated on proteins in these databases, and PTM annotations are
transferred from UniProt. Modifications can also be discovered and added to the
database using bottom-up mass spectrometry data and global PTM discovery in
MetaMorpheus. We demonstrate that such sample-specific databases allow the
identification of variant peptides, modified variant peptides, and variant
proteoforms by searching bottom-up and top-down proteomic data from the Jurkat
human T lymphocyte cell line and demonstrate the identification of
phosphorylated variant sites with phosphoproteomic data from the U2OS human
osteosarcoma cell line. Background ApoAI (apolipoproteins AI) and apoAII (apolipoprotein AII) are
structural and functional proteins of high-density lipoproteins (HDL) which
undergo post-translational modifications at specific residues, creating distinct
proteoforms. While specific post-translational modifications have been reported
to alter apolipoprotein function, the full spectrum of apoAI and apoAII
proteoforms and their associations with cardiometabolic phenotype remains
unknown. Herein, we comprehensively characterize apoAI and apoAII proteoforms
detectable in serum and their post-translational modifications and quantify
their associations with cardiometabolic health indices. Methods and Results
Using top-down proteomics (mass-spectrometric analysis of intact proteins), we
analyzed paired serum samples from 150 CARDIA (Coronary Artery Risk Development
in Young Adults) study participants from year 20 and 25 exams. Measuring 15
apoAI and 9 apoAII proteoforms, 6 of which carried novel post-translational
modifications, we quantified associations between percent proteoform abundance
and key cardiometabolic indices. Canonical (unmodified) apoAI had inverse
associations with HDL cholesterol and HDL-cholesterol efflux, and positive
associations with obesity indices (body mass index, waist circumference), and
triglycerides, whereas glycated apoAI showed positive associations with serum
glucose and diabetes mellitus. Fatty-acid‒modified ApoAI proteoforms had
positive associations with HDL cholesterol and efflux, and inverse associations
with obesity indices and triglycerides. Truncated and dimerized proteoforms of
apoAII were associated with HDL cholesterol (positively) and obesity indices
(inversely). Several proteoforms had no significant associations with phenotype.
Conclusions Associations between apoAI and AII and cardiometabolic indices are
proteoform-specific. These results provide "proof-of-concept" that precise
chemical characterization of human apolipoproteins will yield improved insights
into the complex pathways through which proteins signify and mediate health and
disease. The combined use of electrospray ionization run in so-called "native mode" with
top-down mass spectrometry (nTDMS) is enhancing both structural biology and
discovery proteomics by providing three levels of information in a single
experiment: the intact mass of a protein or complex, the masses of its subunits
and non-covalent cofactors, and fragment ion masses from direct dissociation of
subunits that capture the primary sequence and combinations of diverse
post-translational modifications (PTMs). While intact mass data are readily
deconvoluted using well-known software options, the analysis of fragmentation
data that result from a tandem MS experiment - essential for proteoform
characterization - is not yet standardized. In this tutorial, we offer a
decision-tree for the analysis of nTDMS experiments on protein complexes and
diverse bioassemblies. We include an overview of strategies to navigate this
type of analysis, provide example data sets, and highlight software for the
hypothesis-driven interrogation of fragment ions for localization of PTMs,
metals, and cofactors on native proteoforms. Throughout we have emphasized the
key features (deconvolution, search mode, validation, other) that the reader can
consider when deciding upon their specific experimental and data processing
design using both open-access and commercial software. Proteins are the primary effectors of function in biology, and thus, complete
knowledge of their structure and properties is fundamental to deciphering
function in basic and translational research. The chemical diversity of proteins
is expressed in their many proteoforms, which result from combinations of
genetic polymorphisms, RNA splice variants, and posttranslational modifications.
This knowledge is foundational for the biological complexes and networks that
control biology yet remains largely unknown. We propose here an ambitious
initiative to define the human proteome, that is, to generate a definitive
reference set of the proteoforms produced from the genome. Several examples of
the power and importance of proteoform-level knowledge in disease-based research
are presented along with a call for improved technologies in a two-pronged
strategy to the Human Proteoform Project. |
Telomestatin is derived from what organism? | Telomestatin is a natural macrocyclic compound derived from Streptomyces anulatus 3533-SV4 | Telomestatin is a natural product isolated from Streptomyces anulatus 3533-SV4
and has been shown to be a very potent telomerase inhibitor. The structural
similarity between telomestatin and a G-tetrad suggested to us that the
telomerase inhibition might be due to its ability either to facilitate the
formation of or trap out preformed G-quadruplex structures, and thereby
sequester single-stranded d[T(2)AG(3)](n) primer molecules required for
telomerase activity. Significantly, telomestatin appears to be a more potent
inhibitor of telomerase (5 nM) than any of the previously described
G-quadruplex-interactive molecules. In this communication we provide the first
experimental evidence that telomestatin selectively facilitates the formation of
or stabilizes intramolecular G-quadruplexes, in particular, that produced from
the human telomeric sequence d[T(2)AG(3)](4). A simulated annealing (SA) docking
approach was used to study the binding interactions of telomestatin with the
intramolecular antiparallel G-quadruplex structure. Each intramolecular
G-quadruplex molecule was found to bind two telomestatin molecules (unpublished
results). A 2:1 model for the telomestatin bound in the external stacking mode
in an energy minimized complex with the human telomeric basket-type G-quadruplex
was constructed. Our observation that a G-quadruplex-interactive molecule
without significant groove interactions is able to reorient in a G-quadruplex
structure proints to the importance of core interaction with an asymmetric
G-quadruplex structure in producing selective binding. Furthermore, the
G-quadruplex interactions of telomestatin are more selective for the
intramolecular structure in contrast to other G-quadruplex-interactive agents,
such as TMPyP4. A novel telomerase inhibitor, telomestatin, isolated from Streptomyces anulatus
is the most potent telomerase inhibitor so far. Telomestatin specifically
inhibited telomerase without affecting reverse transcriptases and polymerases.
In addition, telomestatin induced telomere shortening, but its ratio was
extremely faster than that observed in physiological telomere shortening. These
results suggested the existence of other mechanisms to inhibit telomerase.
Telomeres consist of guanine rich sequences which compose a characteristic
three-dimensional structure designated as G-quadruplex. Stabilization of
G-quadruplex structure inhibited the catalysis of not only telomerase but also
other DNA interacting molecules. Telomestatin potently stabilized G-quadruplex
structure in a specific manner. G-quadruplex structure is also involved in a lot
of oncogene promoters. Thus, telomestatin provide the novel therapeutic
molecular target for cancer chemotherapy. G-quadruplexes (G4s) are higher-order structures formed by guanine-rich
sequences of nucleic acids, such as the telomeric 5'-TTAGGG-3'/5'-UUAGGG-3'
repeats and those in gene regulatory regions. G4s regulate various biological
events, including replication, transcription, and translation. Imbalanced G4
dynamics is associated with diseases, such as cancer and neurodegenerative
diseases. Telomestatin is a natural macrocyclic compound derived from
Streptomyces anulatus 3533-SV4. It interacts with the guanine quartet via π-π
stacking and potently stabilizes G4. Because G4 stabilization at the telomeric
repeat inhibits the telomere-synthesizing enzyme telomerase, telomestatin was
originally identified as a telomerase inhibitor. Whereas non-toxic doses of
telomestatin induce gradual shortening of telomeres and eventual crisis in human
cancer cells, higher doses trigger prompt replication stress and DNA damage
responses, resulting in acute cell death. Suppression of the transcription and
translation of G4-containing genes is also implicated in the anticancer effects
of telomestatin. Because telomestatin is rare, labile, and insoluble, synthetic
oxazole telomestatin derivatives have been developed and verified for their
therapeutic efficacies in preclinical cancer models. Furthermore, a variety of
G4-stabilizing compounds have been reported as promising seeds for molecular
cancer therapeutics. To improve the design of future clinical studies, it will
be important to identify predictive biomarkers of drug efficacy. |
Which plant is khellin extracted from? | Khellin is extracted from the seeds of the plant Ammi visnaga. | The chromones are a class of chemical compounds characterised by the presence of
the structure 5:6 benz-1:4-pyrone in their chemical make-up. The first chromone
in clinical use, khellin, was extracted from the seeds of the plant Ammi
visnaga, and had been used for centuries as a diuretic and as a smooth muscle
relaxant. Its use in bronchial asthma was reported in 1947. In the 1950s,
Benger's Laboratories embarked on a research programme to synthesise and develop
modifications of khellin for the treatment of asthma. New compounds were
screened using animal models to test the ability of the compound to prevent the
anaphylactic release of histamine and SRS-A (leukotrienes) from sensitised
guinea pig lung, and a human model to check the ability to reduce the
bronchoconstriction induced by inhaled antigen bronchial challenge. For initial
screening the human work was undertaken by Dr. R.E.C. Altounyan, who suffered
from allergic bronchial asthma and was employed by Benger's Laboratories. After
8 years and more than 600 challenges using over 200 compounds, in 1965 Altounyan
arrived at disodium cromoglycate (DSCG), the chromone that met the criteria of
providing more than 6 h of protection. DSCG is still used today as a mast cell
stabiliser. |
Describe ANTISOMA | The ANTISOMA method is a computerized pipeline for the reduction of the aggregation tendency of monoclonal antibodies (mAbs) based on an automated amino acid substitution approach. The method is available online at http://bioinformatics.biol.uoa.gr/antisoma. | |
Which factors are inhibited by Abelacimab? | Abelacimab is a novel dual inhibitor of Factor XI and Factor XIa. | BACKGROUND: The role of factor XI in the pathogenesis of postoperative venous
thromboembolism is uncertain. Abelacimab is a monoclonal antibody that binds to
factor XI and locks it in the zymogen (inactive precursor) conformation.
METHODS: In this open-label, parallel-group trial, we randomly assigned 412
patients who were undergoing total knee arthroplasty to receive one of three
regimens of abelacimab (30 mg, 75 mg, or 150 mg) administered postoperatively in
a single intravenous dose or to receive 40 mg of enoxaparin administered
subcutaneously once daily. The primary efficacy outcome was venous
thromboembolism, detected by mandatory venography of the leg involved in the
operation or objective confirmation of symptomatic events. The principal safety
outcome was a composite of major or clinically relevant nonmajor bleeding up to
30 days after surgery.
RESULTS: Venous thromboembolism occurred in 13 of 102 patients (13%) in the
30-mg abelacimab group, 5 of 99 patients (5%) in the 75-mg abelacimab group, and
4 of 98 patients (4%) in the 150-mg abelacimab group, as compared with 22 of 101
patients (22%) in the enoxaparin group. The 30-mg abelacimab regimen was
noninferior to enoxaparin, and the 75-mg and 150-mg abelacimab regimens were
superior to enoxaparin (P<0.001). Bleeding occurred in 2%, 2%, and none of the
patients in the 30-mg, 75-mg, and 150-mg abelacimab groups, respectively, and in
none of the patients in the enoxaparin group.
CONCLUSIONS: This trial showed that factor XI is important for the development
of postoperative venous thromboembolism. Factor XI inhibition with a single
intravenous dose of abelacimab after total knee arthroplasty was effective for
the prevention of venous thromboembolism and was associated with a low risk of
bleeding. (Funded by Anthos Therapeutics; ANT-005 TKA EudraCT number,
2019-003756-37.). |
What is vesiduction? | 'Vesiduction' as a fourth mode of intercellular DNA transfer. | The global spread of antibiotic resistance has posed a serious threat to public
healthcare and undermined decades of progress made in the fight against
bacterial infections. It has been demonstrated that the lack of novel effective
antibiotics and rapid spread of antibiotic resistance genes via horizontal
transfer in the ecosystem are mainly responsible for this crisis. Notably,
plasmid-mediated horizontal transfer of antibiotic resistance genes (ARGs) is
recognized as the most domit dissemination pathway of ARGs in humans, animals
and environmental settings. Antibiotic selective pressure has always been
regarded as one of the crucial contributors to promoting the dissemination of
antibiotic resistance through horizontal gene transfer (HGT). However, the roles
of exogenous compounds and particularly non-antibiotic drugs in the spread of
ARGs are still underappreciated. In this review, we first summarize the major
pathways of HGT in bacteria, including conjugation, transformation, transduction
and vesiduction. Subsequently, an overview of these compounds capable of
promoting the HGT is presented, which guides to the formulation of more
reasonable dosing regimens and drug residue standards in clinical practice. By
contrast, these compounds that display an inhibition effect on HGT are also
highlighted, which provides a unique strategy to minimize the spread of ARGs.
Lastly, we discuss the implementations and challenges in bringing these HGT
inhibitors into clinical trials. |
What is the route of administration of eptinezumab? | Eptinezumab is administered intravenously. | Eptinezumab-jjmr (referred to as eptinezumab hereafter; Vyepti™) is a humanised
monoclonal antibody that binds to calcitonin gene-related peptide (CGRP) and
blocks its binding to the receptor. CGRP is believed to play a major role in the
pathophysiology of migraine. Eptinezumab, delivered by intravenous (IV)
administration, is being developed by Lundbeck Seattle BioPharmaceuticals for
the prevention of migraine. In February 2020, eptinezumab was approved in the
USA for the preventive treatment of migraine in adults. This article summarizes
the milestones in the development of eptinezumab leading to this first approval. |
What kind of approaches you need to combine in order to manage Familial spontaneous pneumothorax? | Clinical, radiological and genetic approaches | Familial spontaneous pneumothorax (FSP) accounts for 10% of primary spontaneous
pneumothoraces. Appropriate investigation of FSP enables early diagnosis of
serious monogenic diseases and the practice of precision medicine. Here, we show
that a pneumothorax genetics multidisciplinary team (MDT) can efficiently
diagnose a range of syndromic causes of FSP. A sizeable group (73.6%) of
clinically unclassifiable FSPs remains. Using whole genome sequencing we
demonstrate that most of these cases are not known monogenic disorders.
Therefore, clinico-radiological assessment by an MDT has high sensitivity for
currently known clinically important monogenic causes of FSP, which has
relevance for the design of efficient pneumothorax services. |
What is the mechanism of action of Vericiguat? | Vericiguat is a stimulator of soluble guanylate cyclase. It was developed for treatment of chronic heart failure with reduced ejection fraction. | Despite advances in therapy, patients with heart failure (HF) continue to
experience unacceptably high rates of hospitalization and death, as well as poor
quality of life. As a consequence, there is an urgent need for new treatments
that can improve the clinical course of the growing worldwide population of HF
patients. Serelaxin and ularatide, both based on naturally occurring peptides,
have potent vasodilatory as well as other effects on the heart and kidneys. For
both agents, phase 3 studies that are designed to determine whether they improve
outcomes in patients with acute HF have completed enrollment. TRV027, a biased
ligand for the type 1 angiotensin receptor with effects that extend beyond
traditional angiotensin-receptor blockers is also being studied in the acute HF
population. Omecamtiv mecarbil, an inotropic agent that improves myocardial
contractility by a novel mechanism, and vericiguat, a drug that stimulates
soluble guanylate cyclase, are both being developed to treat patients with
chronic HF. Finally, despite the negative results of the CUPID study, gene
transfer therapy continues to be explored as a means of improving the function
of the failing heart. The basis for the use of these drugs and their current
status in clinical trials are discussed. (Circ J 2016; 80: 1882-1891). AIMS: Exploratory assessment of the potential benefits of the novel soluble
guanylate cyclase stimulator vericiguat on health status in patients with heart
failure (HF) with preserved ejection fraction.
METHODS AND RESULTS: The SOCRATES-PRESERVED trial randomized patients with
chronic HF and ejection fraction ≥ 45% within 4 weeks of decompensation to 12
weeks of treatment with titrated doses of vericiguat (1.25, 2.5, 5, and 10 mg
once daily) or placebo. Health status was assessed with the disease-specific
Kansas City Cardiomyopathy Questionnaire (KCCQ) and the generic health-related
quality of life measure EQ-5D. In total, 477 patients were randomized 12.9 ± 9.0
days after hospitalization or if requiring outpatient treatment with intravenous
diuretics for HF. Baseline KCCQ clinical summary score (CSS), a combination of
symptom and physical function domains, was 52.3 ± 20.4 in the 10 mg arm and 54.1
± 23.0 in placebo, and EQ-5D US index score was 0.74 ± 0.2 and 0.73 ± 0.2,
respectively. A larger proportion of patients treated with vericiguat in the 10
mg arm, compared with placebo, achieved clinically meaningful improvements in
KCCQ-CSS (82.0% vs. 59.0%, number needed to treat = 4.35, P = 0.0052). Important
domains of the KCCQ as well as EQ-5D scores demonstrated a dose-dependent
relationship with vericiguat. In the 10 mg arm, the mean physical limitations
domain increased by +17.2 ± 19.1 at 12 weeks, compared with +4.5 ± 21.6 in
placebo (P = 0.0009). The EQ-5D US index score increased by +0.064 ± 0.167 in
the 10 mg arm, compared with a decrease of -0.009 ± 0.195 in placebo (P =
0.0461). Improvements in KCCQ and EQ-5D scores paralleled physician-assessed
NYHA class and clinical congestion.
CONCLUSION: Vericiguat, in exploratory hypothesis-generating analyses, was
associated with clinically important improvements in patients' health status, as
assessed by the KCCQ and EQ-5D. Further studies should be conducted to test the
hypothesis that vericiguat improves physical functioning and health-related
quality of life in patients with HF with preserved ejection fraction. This trial sought to evaluate whether vericiguat, a novel oral soluble guanylate
cyclase (sGC) stimulator, was superior to placebo, on a background of standard
of care, in increasing the time to the first occurrence of the composite
endpoints of cardiovascular (CV) death and heart failure (HF) hospitalization in
patients with HF with reduced ejection fraction (HFrEF). Deficiency in
sGC-derived cyclic guanosine monophosphate (cGMP) causes both myocardial
dysfunction and impaired endothelium-dependent vasomotor regulation that
includes the myocardial microcirculation. Experimental studies have suggested
multiple potential benefits of sGC stimulators including prevention, or even
reversal, of left ventricular hypertrophy and fibrosis, as well as reduction of
ventricular afterload through both systemic and pulmonary vasodilation. Hence,
restoration of sufficient nitric oxide (NO)-sGC-cGMP signaling has been proposed
as an important treatment target in HF. Vericiguat has been shown to directly
stimulate sGC and enhance sGC sensitivity to endogenous NO. Available phase IIb
data in HFrEF patients indicate vericiguat is safe and well-tolerated, and
exploratory analyses indicate that it results in a dose-dependent, clinically
significant reduction in N-terminal pro-B-type natriuretic peptide (NT-proBNP)
at the highest tested dose. VICTORIA (Vericiguat Global Study in Subjects With
Heart Failure With Reduced Ejection Fraction) is a randomized,
placebo-controlled, parallel group, multicenter, double-blind, event-driven
phase 3 trial of vericiguat in subjects with HFrEF. Approximately 4,872 subjects
will be randomized to evaluate the efficacy and safety of vericiguat
compared with placebo on a background of standard of care. After a screening
phase of up to 30 days, eligible subjects will be treated until the required
number of cardiovascular deaths is observed. The estimated median follow-up
duration is approximately 18 months. All subjects will be followed until study
completion to assess for the occurrence of endpoint events. VICTORIA will
establish the efficacy and safety of vericiguat on cardiovascular death and HF
hospitalization in patients with HFrEF. (A Randomized Parallel-Group,
Placebo-Controlled, Double-Blind, Event-Driven, Multi-Center Pivotal Phase III
Clinical Outcome Trial of Efficacy and Safety of the Oral sGC Stimulator
Vericiguat in Subjects With Heart Failure With Reduced Ejection Fraction
[HFrEF]-VerICiguaT Global Study in Subjects With Heart Failure With Reduced
Ejection Fraction [VICTORIA]; NCT02861534). Background The VITALITY-HFpEF trial (Evaluate the Efficacy and Safety of the
Oral sGC Stimulator Vericiguat to Improve Physical Functioning in Daily Living
Activities of Patients With Heart Failure and Preserved Ejection Fraction) is
designed to determine the efficacy and safety of a novel oral soluble guanylate
cyclase stimulator, vericiguat, on quality of life and exercise tolerance in
heart failure patients with preserved ejection fraction (HFpEF). Impaired
physical functioning reduces the quality of life in patients with HFpEF. The
primary goal of HF treatment along with improving survival is to improve
function, reduce symptoms, and maximize quality of life. Abnormal cyclic
guanosine monophosphate signaling may contribute to physical limitations in
patients with HFpEF via central and peripheral mechanisms. Exploratory post hoc
analyses from a prior trial showed that vericiguat can improve patient-relevant
domains of the Kansas City Cardiomyopathy Questionnaire, especially the physical
limitation score. Methods and Results VITALITY-HFpEF is a placebo-controlled,
double-blind, multi-center, phase IIb trial of ≈735 patients, ≥45 years with
HFpEF and ejection fraction ≥45% who will be randomized 1:1:1 to placebo, 10 mg,
or 15 mg vericiguat. The primary end point is change in Kansas City
Cardiomyopathy Questionnaire physical limitation score from baseline to week 24
and change in 6-minute walk test from baseline to week 24 is the secondary end
point. Conclusions VITALITY-HFpEF is the first trial designed to assess the
efficacy of vericiguat in patients with HFpEF using the Kansas City
Cardiomyopathy Questionnaire physical limitation score as a novel primary end
point. This study will also extend the prior dosing experience with vericiguat
in HF by studying the safety and efficacy of a 15 mg dose. Clinical Trial
Registration URL: https://www.clinicaltrials.gov . Unique identifier:
NCT03547583. BACKGROUND: Vericiguat is a stimulator of soluble guanylate cyclase currently
under investigation as a first-in-class therapy for worsening chronic heart
failure (NCT02861534). Patients with heart failure often require polypharmacy
because of comorbidities. Hence, understanding the clearance mechanisms,
elimination, and potential for pharmacokinetic drug-drug interactions of
vericiguat is important for dose recommendations in this patient population.
METHODS: Biotransformation and perpetrator properties of vericiguat were
characterized in vitro using human hepatocytes, liver microsomes, and
recombit enzymes. This was complemented by a human mass balance study and ten
drug-drug interaction studies in healthy volunteers wherein vericiguat was
co-administered orally with omeprazole, magnesium/aluminum hydroxide,
ketoconazole, rifampicin, mefenamic acid, midazolam, warfarin, digoxin,
sacubitril/valsartan, aspirin, or sildenafil.
RESULTS: In the human mass balance study, mean total radioactivity recovered was
98.3% of the dose administered (53.1% and 45.2% excreted via urine and feces,
respectively). The main metabolic pathway of vericiguat is glucuronidation via
uridine diphosphate-glucuronosyltransferase 1A9 and 1A1. In vitro studies
revealed a low risk of vericiguat acting as a perpetrator by inhibiting
cytochrome P450s, uridine diphosphate-glucuronosyltransferase isoforms, or major
transport proteins, or by inducing cytochrome P450s. These observations were
supported by phase I drug-drug interaction studies. Phase I studies that
assessed the propensity of vericiguat as a victim drug showed changes in the
range that did not warrant recommendations for dose adjustment in phase III.
CONCLUSIONS: A low pharmacokinetic interaction potential of vericiguat was
estimated from in vitro data and confirmed in vivo. Thus, vericiguat is suitable
for a patient population with multiple comorbidities requiring polypharmacy. BACKGROUND: Vericiguat, a direct stimulator of soluble guanylate cyclase, has
been developed as a first-in-class therapy for symptomatic chronic heart failure
(HF) and ejection fraction < 45%.
METHODS: Safety, pharmacodynamic (PD), and pharmacokinetic (PK) interactions
between vericiguat and drugs used in HF (sacubitril/valsartan [SV] and aspirin
[acetylsalicylic acid]) or with a narrow therapeutic index (warfarin) were
evaluated in three phase I studies.
RESULTS: Vericiguat 15 mg (single dose [SD]) had no effect on bleeding time or
platelet aggregation when coadministered with aspirin 1000 mg versus aspirin
alone: estimated differences in least squares means 2.7% (95% confidence
interval [CI] - 90.4 to 95.8) and 2.4% (95% CI - 7.0 to 11.8) turbidimetry,
respectively. Vericiguat 10 mg (once daily) had no effect on coagulation
inhibition elicited by warfarin 25 mg (SD; mean ratios of area under the
concentration-time curve from time zero to 96 h for clotting parameter treatment
comparisons approximated 100.0%). There were no clinically relevant PD changes
whether SV 97/103 mg was administered with single or multiple doses of
vericiguat 2.5 mg or placebo (differences in systolic blood pressure
[BP] - 1.66 mmHg [90% CI - 4.22 to 0.90]; diastolic BP - 1.80 mmHg [90%
CI - 3.24 to - 0.36]; heart rate - 0.33 beats/min [90% CI - 2.25 to 1.60]).
Vericiguat demonstrated no PK interactions when coadministered with aspirin,
warfarin, or SV at steady state. Treatments were well tolerated.
CONCLUSIONS: Coadministration of vericiguat with SV, aspirin, or warfarin was
well tolerated. No clinically relevant PD or PK interactions were observed,
supporting concomitant use of these drugs, commonly used by patients with HF,
with vericiguat and no dose adjustment.
EUDRACT NUMBER: 2014-000765-52; 2014-004880-19; 2015-004809-16. The significant morbidity and mortality associated with heart failure with
reduced ejection fraction (HFrEF) or heart failure with preserved ejection
fraction (HFpEF) justify the search for novel therapeutic agents. Reduced cyclic
guanosine monophosphate levels contribute to HF progression. Among molecules
modulating the nitric oxide (NO)-GMP-phosphodiesterase (PDE) pathway, the
evaluation of nitrates, synthetic natriuretic peptides (NP), and NP analogs has
yielded mixed results. Conversely, sacubitril/valsartan, combining NP
degradation inhibition through neprilysin and angiotensin receptor blockade, has
led to groundbreaking findings in HFrEF. Other strategies to increase tissue
cyclic guanosine monophosphate have been attempted, such as PDE-3 or PDE-5
inhibition (with negative or neutral results), NO-independent soluble guanylate
cyclase (sGC) activation, or enhancement of sGC sensitivity to endogenous NO.
Following the positive results of the phase 3 VICTORIA (A Study of Vericiguat in
Participants With Heart Failure With Reduced Ejection Fraction) trial on the sGC
stimulator vericiguat in HFrEF, the main open questions are the efficacy of the
sacubitril/valsartan-vericiguat combination in HFrEF and of vericiguat in HFpEF. Vericiguat (VERQUVO™; Merck & Co, Bayer AG) is a soluble guanylate cyclase (sGC)
stimulator being developed for the treatment of chronic heart failure.
Vericiguat stimulates sGC and cGMP production independent of nitric oxide (NO)
and enhances the effects of NO by stabilizing the NO-sGC binding. Based on the
results of the phase III VICTORIA trial vericiguat was recently approved in the
USA for risk reduction in patients with heart failure and ejection fraction
< 45%. This article summarizes the milestones in the development of vericiguat
leading to this first approval. Heart failure is a common entity encountered in healthcare with a vast
socioeconomic impact. Recent advances in pharmacotherapy have led to the
development of novel therapies with mortality benefits, improvement in heart
failure symptoms and hospitalizations. This article is intended to explore those
newer pharmacotherapies and summarize the evidence behind guideline directed
medical therapy (GDMT) for heart failure with reduced ejection fraction (HFrEF).
It has been several years since any significant advances in pharmacotherapy of
heart failure have resulted in survival benefit. Angiotensin-neprilysin
inhibitors through the PARADIGM-HF and PIONEER-HF trials have shown mortality
benefits and a reduction in heart failure hospitalizations and are considered
landmark trials in heart failure. Vericiguat is an oral guanylate cyclase
stimulator that through the recent VICTORIA trial showed a 10% relative
difference in death from cardiovascular cause or hospitalization for heart
failure. The sodium-glucose transport protein 2 (SGLT2) inhibitors are another
class of medications that have shown promise in the treatment of patients with
HFrEF and diabetes mellitus. The CANVAS and EMPA-REG OUTCOME trials showed the
potential benefit of SGLT2 inhibitors on cardiovascular mortality, DECLARE-TIMI
58 trial showed that treatment with dapagliflozin reduced the risk of
cardiovascular death or hospitalization for heart failure to a greater extent in
patients with reduced ejection fraction (EF). Although novel pharmacotherapy is
the current focus of intense research, there have been numerous studies on
potential benefit of iron supplementation in ferropenic patients with heart
failure. Another rapidly expanding area of research in the realm of heart
failure is precision medicine and its impact on the development, progression,
and treatment of heart failure. The field of heart failure is dynamic and with
the influx of data from recent and ongoing trials, newer therapies with
morbidity and mortality benefits in HFrEF are now available, nonetheless, much
work is still needed. BACKGROUND: Vericiguat, a stimulator of soluble guanylate cyclase, has been
developed as a first-in-class therapy for worsening chronic heart failure in
adults with left ventricular ejection fraction < 45%.
OBJECTIVE: The objective of this article was to characterize the
pharmacokinetics and pharmacokinetic variability of vericiguat combined with
guideline-directed medical therapy (standard of care), and identify
exposure-response relationships for safety (hemodynamics) and pharmacodynamic
markers of efficacy (N-terminal pro-B-type natriuretic peptide concentration
[NT-proBNP]) in patients with heart failure and left ventricular ejection
fraction < 45% in the SOCRATES-REDUCED study (NCT01951625).
METHODS: Vericiguat and NT-proBNP plasma concentrations in 454 and 432 patients
in SOCRATES-REDUCED, respectively, were analyzed using nonlinear mixed-effects
modeling.
RESULTS: Vericiguat pharmacokinetics were well described by a one-compartment
model with apparent clearance, apparent volume of distribution, and absorption
rate constant. Age, bodyweight, plasma bilirubin, and creatinine clearance were
identified as significant covariates on apparent clearance; sex and bodyweight
on apparent volume of distribution; and bodyweight and plasma albumin level on
absorption rate constant. Pharmacokinetic/pharmacodynamic analysis showed
initial minor and transient effects of vericiguat on blood pressure with low
clinical impact. There were no changes in heart rate following initial or
repeated vericiguat administration. An exposure-dependent and time-dependent
turnover pharmacokinetic/pharmacodynamic model for NT-proBNP described
production and elimination rates and an demonstrated exposure-dependent
reduction in [NT-proBNP] by vericiguat plus standard of care compared with
placebo plus standard of care. This effect was dependent on baseline
[NT-proBNP].
CONCLUSIONS: Vericiguat has predictable pharmacokinetics, with no long-term
effects on blood pressure in patients with heart failure and left ventricular
ejection fraction < 45%. A pharmacokinetic/pharmacodynamic model described a
vericiguat exposure-dependent reduction of NT-proBNP.
CLINICAL TRIAL IDENTIFIER: NCT01951625. African Americans (AA) have a higher prevalence of heart failure (HF) when
compared with White Americans (3% vs 2%), respectively and HF comes on at an
earlier age and is more severe in AA. The A-HEFT trial with the combination of
hydralazine and isosorbide dinitrate (ISDNHYD) for self-described AA with NYHA
class III-IV heart failure with reduced ejection fraction (HFrEF) showed
reduction in mortality and HF hospitalizations with a class I level of evidence
A recommendation in the ACC/AHA guidelines. Vericiguat is an oral soluble
guanylate cyclase stimulator that enhances the cyclic guanosine monophosphate
(GMP) pathway. A randomized, double-blind, placebo-controlled trial in patients
with higher risk HFrEF in which AA were underrepresented found that vericiguat
reduced the composite primary outcome of cardiovascular death or first HF
hospitalization. In the new era of guideline directed medical therapies of
quadruple therapy - hydralazine and isosorbide dinitrate should be preferred
over vericiguat in AA with HFrEF. The significant morbidity and mortality associated with heart failure with
reduced (HFrEF) or preserved ejection fraction (HFpEF) justify the search for
novel therapeutic agents. The nitric oxide (NO)-soluble guanylate cyclase
(sGC)-cyclic guanosine monophosphate (cGMP) pathway plays an important role in
the regulation of cardiovascular function. This pathway is disrupted in HF
resulting in decreased protection against myocardial injury. The sGC activator
cinaciguat increases cGMP levels by direct, NO-independent activation of sGC,
and may be particularly effective in conditions of increased oxidative stress
and endothelial dysfunction, and then reduced NO levels, but this comes at the
expense of a greater risk of hypotension. Conversely, sGC stimulators (riociguat
and vericiguat) enhance sGC sensitivity to endogenous NO, and then exert a more
physiological action. The phase 3 VICTORIA trial found that vericiguat is safe
and effective in patients with HFrEF and recent HF decompensation. Therefore,
adding vericiguat may be considered in individual patients with HFrEF,
particularly those at higher risk of HF hospitalization; the efficacy of the
sacubitril/valsartan-vericiguat combination in HFrEF is currently unknown. PURPOSE OF REVIEW: The nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic
guanosine monophosphate (cGMP) pathway plays an important role in the regulation
of cardiovascular function, and it is disrupted in heart failure (HF), resulting
in decreased protection against myocardial injury. Impaired NO-sGC-cGMP
signaling in HF is secondary to reduced NO bioavailability and altered redox
state of sGC, which becomes less responsive to NO. The sGC activator cinaciguat
increases cGMP levels by direct NO-independent activation of sGC and may be
particularly effective in conditions of increased oxidative stress and
endothelial dysfunction, and therefore reduced NO levels, at the expense of a
greater risk of hypotension. Conversely, sGC stimulators (riociguat and
vericiguat) enhance sGC sensitivity to endogenous NO, thus exerting a more
physiological action.
RECENT FINDINGS: Clinical trials have suggested the benefit of vericiguat in
patients with high-risk HF; in particular, a lower incidence of death from
cardiovascular causes or HF hospitalization. Adding vericiguat may be considered
in individual patients with HF, and reduced left ventricular ejection fraction
(HFrEF) particularly those at higher risk of HF hospitalization. OBJECTIVE: To review the efficacy and safety of vericiguat indicated to reduce
the risk of cardiovascular death and heart failure (HF) hospitalization
following hospitalization or need for outpatient intravenous diuretics in adult
patients with chronic symptomatic HF and ejection fraction (EF) less than 45%.
DATA SOURCES: A literature search through MEDLINE with search terms MK1242, BAY
1021189, and vericiguat was conducted. Product labeling and English-language
studies assessing pharmacokinetics, pharmacodynamics, efficacy, or safety of
vericiguat were included.
STUDY SELECTION AND DATA EXTRACTION: Preclinical and clinical studies describing
the efficacy and safety of vericiguat were included.
DATA SYNTHESIS: The phase 3 VICTORIA clinical trial demonstrated a lower
composite primary outcome of death from cardiovascular causes or first
hospitalization in the vericiguat group compared to placebo. Total
hospitalizations for HF in the vericiguat group were significantly less compared
to placebo. The composite secondary outcome of death from any cause or first HF
hospitalization was significantly less in the vericiguat group.
RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: The addition of vericiguat
offers a new treatment option for those in whom rehospitalization or recurrent
outpatient intravenous diuretic treatment is a concern. Given high rates of
nonadherence in HF patients, vericiguat represents an additional treatment
option, especially for patients who do not tolerate available HF therapies.
CONCLUSION: Vericiguat is a novel soluble guanylate cyclase stimulator that is
safe and effective for reducing the risk of cardiovascular death and HF
hospitalization in adults with symptomatic chronic HF and reduced EF. Vericiguat, a novel stimulator of soluble guanylate cyclase (sGC), has shown
promising results in patients with heart failure and reduced ejection fraction
(HFrEF) in the recent VICTORIA trial. The nitric oxide (NO)-sGC-cyclic guanosine
monophosphate (cGMP) signaling pathway is disturbed in heart failure, leading to
increased formation of reactive oxygen species and reduced NO bioavailability,
and resultant myocardial dysfunction, adverse left ventricular remodeling, and
cardiorenal syndrome. Restoration of sufficient NO-sGC-cGMP signaling has been
proposed as an important treatment target in heart failure, beyond neurohormonal
blockage and afterload reduction. Vericiguat has a dual mode of action on this
axis, it both sensitizes sGC to low levels of NO, and can directly stimulate sGC
in the absence of any endogenous NO. VICTORIA was a Phase 3 trial that compared
vericiguat, at a target dose of 10 mg, with placebo in 5050 patients with HFrEF
(ejection fraction < 45%) on top of guideline-indicated therapy. The composite
endpoint was the first occurrence of cardiovascular death or hospitalization for
heart failure. The median follow up was 10.8 months. The included patients had
to have had a heart failure-related hospitalization or need of IV diuretic
therapy in the past 6 months, making it a particularly high risk and vulnerable
patient population. The composite endpoint occurred less frequently with
vericiguat than with placebo (35.5% vs 38.5%, p = 0.02). Adverse events were
common in both groups, syncope was more common with vericiguat than with placebo
(4% vs 3.5%, p = 0.03). Compared to the other recent large trials in HFrEF,
PARADIGM-HF and DAPA-HF, patients in VICTORIA were older, more symptomatic (up
to 40% NYHA IIIIV class), had higher N-terminal-pro hormone B-type natriuretic
peptide (NT-proBNP) levels, and were more vulnerable since 84% had been
hospitalized for heart failure in the previous 6 months. While drugs involving
the neurohormonal pathways are effective in slowing down the progression of
disease in more stable HFrEF, vericiguat may be a drug of choice particularly in
the highest risk patients with recent or recurrent hospitalizations despite full
background medication. The drug has also shown safety in patients with reduced
renal function. This article discusses the place in therapy of vericiguat in
patients with HFrEF, which is a heterogenous group in terms of etiology,
clinical profiles, and comorbidities. |
What is the origin of HEp-2 cells? | human larynx epidermoid carcinoma cell line (HEp-2) | The fungicide agents are a key component in the fruits and vegetables
production. The Iprodione residues are one of the pesticide more frequently
found in food products. The available data about the cytotoxicity of iprodione
and its metabolites are scarce and do not allow characterization of its
genotoxic potential and define the risk assessment.The human larynx epidermoid
carcinoma cell line (HEp-2) has been shown to be sensitive to the toxic effects
of xenobiotics of different origin and have been often used in citotoxicity and
genotoxicity studies. The purpose of this paper is to evaluate the induction of
genotoxicity and the role of oxidative stress in HEp-2cell line by exposure to
the IP. The MTT test for viability resulted in CL50 85.86 (77.05-95.68) μg/mL of
Iprodione. On the basis of this result, we proceeded to expose the cells to the
sublethal concentrations (below the CL50) during 24 h to analyze the mitotic
index and nuclear division index in order to determine the subcytotoxic
concentrations of IP which the genotoxicity was evaluated. The subcytotoxic
concentrations of 7, 17, and 25 μg/mL IP induced aneugenic effects as
micronuclei centromere positive whereas 17 μg/mL was a threshold for centromere
negative micronuclei induction in HEp-2 cells. The abnormal mitosis was induced
for exposition of Hep-2 cells to the three concentrations. According to the
result obtained, citotoxicity and genotoxicity oxidative stress studies were
performed in 1.5, 7.0, and 25 μg/mL of IP. The results showed that the GSH
intracellular content, the SOD activity and the levels of oxidative damage of
the proteins were affected lead to redox imbalance. The decreased in the SOD
activity and protein oxidation were in according to the result obtained to
genotoxicity, suggesting that different biological targets could be affected. The photodynamic therapy (PDT) has been outstanding as a promising alternative
for treating different carcinomas. However, the lack of detailed knowledge on
the mechanisms of action prevents exploitation of the therapy full potential.
Herein we shall evaluate not only the photodynamic efficiency but the mechanism
of cell death triggered by the photoactivated erythrosine in oropharyngeal
cancer cells (HEp-2). Cytotoxic assays were performed by MTT at distinct
concentrations (10-3 to 10-6 mol/L) and incubation time (3, 24 and 48 h) of
erythrosine in HEp-2 in vitro culture. In addition to the cytotoxic effect, the
mechanisms of cell death were evaluated by flow cytometry following the annexin
V/propidium iodide double staining protocol. Erythrosine was incorporated by
HEp-2 cells in a dose- and time-dependent pathway. The incubation of erythrosine
in dark has not shown any significant effect over the culture until 24 h and
1.25×10-6 mol/L concentration, from which a small portion (<25% and
statistically significant) of the cell population have undergone apoptosis. On
the other hand, 50% of cell viability is reduced mainly by necrosis when 10,
3.75 and 1.9×10-6 mol/L of erythrosine concentrations at 3, 24 and 48 h of
incubation are photoactivated, respectively. Bioinspired models of tumor
membrane based on Langmuir monolayers of 2-dioleoyl-sn-glycero-3-phosphocholine
(DOPC) and 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) mixture reveled
that electrostatic interactions with the lipid head groups are the main driving
forces allowing the erythrosine adsorption. Furthermore, light-induced
hydroperoxidation significantly increased the surface area of the monolayers,
which might be the origin of the necrotic pathway triggered in HEp-2 cells. Artepillin C is the main compound present in propolis from Baccharis
dracunculifolia, whose antitumor activity has been the focus of many studies.
Herein, we shall investigate the Artepillin C mechanisms of action against cells
derived from the oropharyngeal carcinoma (HEp-2). Cytotoxicity tests revealed
that the concentrations of Artepillin C required to reduce cell viability by 50%
(CC50) are dependent on the incubation time, decreasing from 40.7 × 10-5 mol/L
to 15.7 × 10-5 mol/L and 9.05 × 10-5 mol/L considering 12, 24 and 48 h,
respectively. Hydrophobic interactions on neutral species of Artepillin C induce
aggregation over the HEp-2 plasma membrane, given the acid conditions of the
cellular culture. Indeed, Langmuir monolayers mimicking cellular membranes of
tumor cells revealed Artepillin C affinity to interact with
1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) containing 20 mol% of
1,2-dipalmitoyl-sn-glychero-3-phosphoserine (DPPS), leading aggregation on giant
unilamellar vesicles (GUVs) at pH 3.2. Moreover, leakage experiments on GUVs
have shown that the presence of DPPS enhances the efflux of the fluorescent
probe signaling the membrane permeabilization, which is the origin of the
necrotic pathway triggered in HEp-2 cells, as observed by flow cytometry assays. |
Does bleomycin cause lung toxicity? | Pulmonary toxicity is a devastating complication of bleomycin chemotherapy. | Bleomycin is potentially capable of inducing a diffuse interstitial fibrosis of
the lung, the pathogenesis of which has not yet been elucidated. The authors
have demonstrated that after 48 hr of acute treatment, morphological and
functional modifications could be seen in type II pneumocytes, which are
responsible for surfactant production. This might be the earliest stage of
pulmonary damage. Bleomycins are a family of compounds produced by Streptomyces verticillis. They
have potent tumour killing properties which have given them an important place
in cancer chemotherapy. They cause little marrow suppression, but pulmonary
toxicity is a major adverse effect. The mechanisms of cell toxicity are well
described based on in vitro experiments on DNA. The bleomycin molecule has two
main structural components: a bithiazole component which partially intercalates
into the DNA helix, parting the strands, as well as pyrimidine and imidazole
structures, which bind iron and oxygen forming an activated complex capable of
releasing damaging oxidants in close proximity to the polynucleotide chains of
DNA. This may lead to chain scission or structural modifications leading to
release of free bases or their propenal derivatives. The mechanisms are well
described based on in vitro experiments on DNA, but how they relate to intact
cells in whole animals is more tenuous. Bleomycin is able to cause cell damage
independent from its effect on DNA by induction lipid peroxidation. This may be
particularly important in the lung and in part account for its ability to cause
alveolar cell damage and subsequent pulmonary inflammation. The lung injury seen
following bleomycin comprises an interstitial oedema with an influx of
inflammatory and immune cells. This may lead to the development of pulmonary
fibrosis, characterized by enhanced production and deposition of collagen and
other matrix components. Several polypeptide mediators capable of stimulating
fibroblasts replication or excessive collagen deposition have been implicated in
this, but the precise role of these in bleomycin-induced fibrosis is yet to be
demonstrated. Current therapy for bleomycin-induced lung damage is inadequate,
with corticosteroids most often used. Given the mechanism of action described
above, antioxidants and iron chelators might be beneficial. Although, studies to
date are equivocal and there is insufficient evidence to promote their use
clinically. Novel drugs are currently being developed and it is hoped these may
be more useful. Bleomycin is an antineoplastic agent that causes a dose-related lung fibrosis
that limits its therapeutic effectiveness. It has been proposed that the
cellular toxicity and antitumor effects of bleomycin occur by formation of
O2-Fe(II)-bleomycin complexes that degrade DNA and release O2- and OH radicals
that attack other cellular components. Twice daily injections of the iron
chelator deferoxamine were utilized in an attempt to ameliorate
bleomycin-induced lung fibrosis. They failed to diminish bleomycin-induced lung
inflammation and fibrosis in rats. Pulmonary fibrosis is the major toxic effect of bleomycin chemotherapy; however,
the molecular mechanisms of the pathological process are unknown. Since alveolar
macrophages produce toxic oxygen metabolites and these can damage lung cells,
the effect of bleomycin on superoxide anion production was investigated in
subpopulations of pig alveolar macrophages. Cells were lavaged from the lung and
separated into three subpopulations according to their density. Their capacity
to generate superoxide anions increased the more distally they were located.
Bleomycin (5.0 milliunits/ml) increased the rate of superoxide production by 75
+/- 24% in dense alveolar macrophages located in the lung periphery.
Hydrocortisone (10.0 micrograms/ml) inhibited this superoxide production by 33
+/- 10%. Results from this study suggest that an excess production of superoxide
anions by alveolar macrophages may be the underlying cause of bleomycin
pulmonary toxicity. Pulmonary toxicity is an important adverse effect of bleomycin treatment. Very
little is known of the mechanisms underlying the development of lung injury,
especially after intravenous administration, or how it can be modulated. In this
study acute lung injury induced by bleomycin has been examined in rats by
assessment of alveolar lavage cell profiles, histological examination, and
measurement of the total pulmonary extravascular albumin space. Intratracheal
instillation of bleomycin 1.5 mg resulted in a severe pneumonitis with influx of
inflammatory cells into the alveoli as assessed by alveolar lavage, oedema of
the alveolar walls, and up to an eight fold increase in the total pulmonary
extravascular albumin space, maximal at 72 hours. Intravenous bleomycin 0.15-5
mg produced no detectable injury when assessed in these ways. Exposure to
hyperoxia (40-90%) after intravenous bleomycin, however, induced lung injury
similar to that produced by intratracheal bleomycin. A much more severe injury
followed administration of intravenous bleomycin after an exposure to hyperoxia,
which itself resulted in lung injury; but lung injury was still detectable after
bleomycin when the exposure to hyperoxia was insufficient to induce changes in
control animals. Lung injury was not observed when the exposure to hyperoxia
preceded bleomycin treatment. These results indicate the importance of oxygen in
the pathways leading to acute lung injury following intravenous bleomycin. We
conclude that exposure to oxygen might induce lung injury during and after
bleomycin treatment, and suggest that in these circumstances oxygen therapy
should be kept to a minimum. Prompted by recent reports of the increasing incidence of late relapses in Stage
1 patients with both maligt teratoma and seminoma on surveillance, a low
toxicity regimen combining etoposide, bleomycin and cisplatin [EBCi(3)] with
prolonged infusion of bleomycin, given daily for 3 days, has been developed for
possible use as adjuvant treatment. Forty of 44 patients treated remain free of
disease with a median follow-up of 21 months and actuarial disease free survival
at 2 years of 91%. There have been no respiratory problems attributable to
bleomycin lung toxicity in this study compared with four (3 associated with
patient deaths) seen in 91 previously treated patients. The relatively low
toxicity and high efficacy of this regime indicate that it may be suitable as
adjuvant treatment. The comparative pulmonary toxicity induced by bleomycin and talisomycin (former
trivial name: tallysomycin A) was evaluated by measuring lung hydroxyproline
content. Based on published subacute toxicity data, in which talisomycin was
found to be four times as toxic as bleomycin, the following doses of each drug
were given sc to BDF1 male mice twice weekly for 4 weeks: 2.5, 5, and 10 mg/kg
of bleomycin and 0.625, 1.25, 2.5, and 3.75 mg/kg of talisomycin. Equivalent
dose-related effects in body weight were produced by bleomycin and talisomycin
at a respective dose ratio of 4:1. Similarly, equivalent dose-dependent
increases in lung hydroxyproline content, an index of collagen, were produced by
bleomycin and talisomycin. Neither drug caused deaths at the doses used. To apply safely an aggressive chemotherapy regimen like CESS 81 requires
intensive supportive care. Bleomycin is evaluated as part of the protocol for
treatment of primary Ewing's sarcoma. Bleomycin might cause pulmonary fibrosis
at higher cumulative doses as toxic effect directly to the lungs or most likely
in addition by the formation of vascular microthrombi. A randomized study is
designed to evaluate if pulmonary changes due to Bleomycin can be prevented
using heparin. As severe bone marrow depression is anticipated the effect of
lithium on the leucocyte nadir is also subject of a randomized study. In order to see if exposure to cold temperature affects the development of
bleomycin lung toxicity in mammals, 14 rats received endotracheal injections of
bleomycin, while another 14 rats received saline. Half of the saline-treated
animals were then exposed to room temperature for 7 days (SRT), and half were
exposed to 4 degrees C for 7 days (SC). The bleomycin-treated animals similarly
yielded groups kept at room temperature (BRT) and in the cold (BC). After 1 wk
the rats were killed and the lungs were sectioned for assessment of histologic
changes. All the bleomycin-treated animals had evidence of lung toxicity but
this was much less marked in group BC than in group BRT. The lungs in group SC
remained normal. These results were confirmed by morphometric methods, which
showed significantly increased volume proportions of alveolar walls in groups
BRT and BC compared with that in groups SRT and SC (p less than 0.001), with BRT
being greater than BC (p less than 0.001). It is concluded that exposure of
bleomycin-treated rats to low ambient temperature significantly reduces lung
toxicity. The effect of hypoxia on the development of bleomycin lung toxicity was studied
in 26 rats. Thirteen rats received an endotracheal injection of saline, and 13
rats received a similar injection of 1.5 units of bleomycin in saline. Six
saline-treated and 6 bleomycin-treated rats were exposed to 10% oxygen for 2
days prior and 2 days subsequent to the injections, and then breathed air for a
further 5 days before being killed. The other rats breathed air continuously,
and were also killed 7 days after the injections. Although all bleomycin-treated
animals had some evidence of lung toxicity, histologic examination of the lungs
revealed markedly reduced bleomycin toxicity in the rats exposed to hypoxia.
This was confirmed by morphometry, which demonstrated that the volume density of
alveolar walls (mean +/- SEM) was significantly lower in the bleomycin-hypoxia
group (11.8 +/- 0.8%) than in the bleomycin-air group (18.8 +/- 1.1%) (p less
than 0.001). It is concluded that hypoxia offers protection against bleomycin
lung toxicity in the rat. A 42 year old man, treated for testicular carcinoma with combination
chemotherapy that included bleomycin, developed life threatening interstitial
pneumonitis. He recovered successfully after treatment with very high doses of
corticosteroids and azathioprine. This report suggests that bleomycin lung
toxicity may be reversible if treated aggressively. In this study we investigated bleomycin-induced pulmonary toxicity in patients
with germ-cell tumour by means of technetium-99m diethylene triamine
penta-acetic acid aerosol scintigraphy. Twenty untreated patients who had no
clinical or radiological evidence of pulmonary disease received four courses of
etoposide, cisplatin and bleomycin chemotherapy. Aerosol lung scintigraphy and
pulmonary function tests were performed in all patients before bleomycin
treatment and after administration of 180 and 360 mg bleomycin. On the basis of
the scintigrams the percentage decline in activity per minute (Kep) was
evaluated, which represented an accurate parameter of lung membrane
permeability. Pretreatment Kep values (0.891 +/- 0.286) were significantly lower
than those obtained following 180 and 360 mg bleomycin treatment (1.176 +/-
0.336 and 1.389 +/- 0.477, respectively; P < 0.0005). The Kep values obtained
with 180 and 360 mg bleomycin treatments were also significantly different (P <
0.005). In contrast, no significant change was observed in the results of
pulmonary function tests. Our results demonstrate that evaluation of the
pulmonary clearance of 99mTc-DTPA represents a useful means of monitoring the
functional status of the lung epithelial membrane during bleomycin treatment.
Further prospective studies are needed to assess the relationship between
increase in permeability and development of lung toxicity in order to decide
which patients should discontinue bleomycin therapy. Bleomycin damages DNA and causes lung injury and fibrosis. To determine whether
bleomycin is associated with the appearance of DNA damage-inducible proteins,
C3H mice received either 0.4 mg bleomycin or normal saline intratracheally and
were killed 1 to 14 d later. The lungs were examined for expression of p53,
p21(WAF1/PiCl), and proliferating cell nuclear antigen (PCNA) using
immunohistochemistry and Western blotting. p53-positive cells first appeared at
5 d after treatment and peaked at 7 d; PCNA-positive cells appeared at 1 d after
treatment and peaked at 7 d; and p21-positive cells appeared at 5 d and peaked
at 9 d. Western blot analysis confirmed that bleomycin upregulated the DNA
damage-inducible proteins in a similar fashion. This is the first evidence that
bleomycin causes a p53-dependent response associated with acute injury in the
lung. OBJECTIVE: Potentially fatal pulmonary toxicity is a dreaded complication of
bleomycin. Increased use of granulocyte colony-stimulating factor in patients
receiving chemotherapy has been paralleled by an increased incidence of
bleomycin-induced pulmonary toxicity. We investigated whether granulocyte
colony-stimulating factor (25 microg x kg(-1) x day(-1), 4 days) enhanced
endotracheal bleomycin-induced (5 mg/kg) acute lung injury and fibrosis in rats.
SETTING: University laboratory.
SUBJECTS: Sprague-Dawley rats.
INTERVENTIONS: We compared the effects of alveolar instillation of bleomycin in
rats treated with either granulocyte colony-stimulating factor or saline.
MEASUREMENTS AND MAIN RESULTS: Mortality was 25% with bleomycin only and 50%
with bleomycin + granulocyte colony-stimulating factor. Granulocyte
colony-stimulating factor increased alveolar neutrophil recruitment, pulmonary
edema, and lung myeloperoxidase activity on day 4. Lung static compliance on day
15 was severely decreased with bleomycin alone and showed a further significant
decrease when granulocyte colony-stimulating factor was added (controls, 3.85
+/- 0.14 mL/kPa; bleomycin, 1.44 +/- 0.06 mL/kPa; and bleomycin + granulocyte
colony-stimulating factor, 0.65 +/- 0.09 mL/kPa; control vs. bleomycin, p
<.0001; and bleomycin vs. bleomycin + granulocyte colony-stimulating factor, p
=.0003). Lung morphology with bleomycin + granulocyte colony-stimulating factor
showed, in addition to the changes observed with bleomycin alone, four patterns
indicating more severe disease: honeycomb foci, pleural thickening with hyaline
fibrosis, interstitial granuloma with increased number of macrophages but not
neutrophils, and established interstitial fibrosis. Lidocaine, which prevents
neutrophil adhesion to endothelial cells, inhibited granulocyte
colony-stimulating factor-related exacerbation of acute lung injury
(bronchoalveolar lavage fluid cells and pulmonary edema) and pulmonary fibrosis
(lung static compliance and morphologic changes).
CONCLUSIONS: Granulocyte colony-stimulating factor enhances bleomycin-induced
lung toxicity by a mechanism that probably involves neutrophils. We describe a 39-year-old male patient who developed bleomycin-induced
pneumonitis 2 years after completion of chemotherapy for nonseminomatous
testicular cancer. Bleomycin sometimes causes fatal pulmonary toxicity,
including bleomycin-induced pneumonitis. The central event in the development of
pneumonitis is endothelial damage of the lung vasculature due to
bleomycin-induced cytokines and free radicals. Pulmonary toxicity usually begins
at bleomycin administration. The development of bleomycin-induced pneumonitis up
to 6 months after bleomycin therapy has also been reported. We report a patient
who developed bleomycin-induced pneumonitis 2 years after the initiation of
bleomycin-containing chemotherapy regimens. BACKGROUND: Our aim was to define predictors of late radiation-induced lung
injury (RILI) in Hodgkin's lymphoma (HL) survivors treated with
bleomycin-containing chemotherapy and radiotherapy.
MATERIAL AND METHODS: Eighty consecutive patients treated with chemotherapy and
subsequent supradiaphragmatic radiation therapy for HL were retrospectively
reviewed for symptoms and/or radiological signs of RILI. Median patient age was
26 years (range 14-55). Left, right, and total lung dosimetric parameters along
with clinical, disease, and treatment-related characteristics were analyzed.
Multivariate logistic regression analyses were performed. A receiver operator
characteristic (ROC) curve analysis was performed to find possible cutoff values
dividing patients into high- and low-risk groups.
RESULTS: Seven of 80 (9%) patients had lung disease at baseline. Four of 80 (5%)
had toxicity after chemotherapy and before the beginning of radiotherapy. These
patients were excluded from further evaluation. At a median time of 10 months
(range 9-18), 9/69 patients (13%) developed lung radiological changes on
computed tomography (CT) after treatment. Four of nine patients were diagnosed
RTOG grade ≥ 2. On multivariate analyses, left-lung V30 (p = 0.004, OR = 1.108
95% CI 1.033-1.189) and total-lung V30 (p = 0.009, OR = 1.146 95% CI
1.035-1.270) resulted to be predictors of lung CT changes with a cutoff value of
16% and 15%, respectively. When only symptomatic RILI was considered a left-lung
V30 cutoff value of 32% was estimated.
CONCLUSION: Bleomycin and RT may cause lung injury in a small, but significant
fraction of HL patients. Left-lung V30 predicts the risk of developing
asymptomatic or symptomatic RILI after sequential chemo-radiotherapy. Author information:
(1)INSERM, LNC UMR 866, Laboratoire d'Excellence LipSTIC, Dijon 21079, France.
Equipe "Heat Shock Proteins" Labellisée par la Ligue Nationale contre le Cancer,
Dijon 21079, France. Faculty of Medicine and Pharmacy of Dijon, Université
Bourgogne Franche-Comté, Dijon 21079, France.
(2)Faculty of Medicine and Pharmacy of Dijon, Université Bourgogne
Franche-Comté, Dijon 21079, France. EPHE, Tumor Immunology and Immunotherapy
Laboratory, Dijon 21079, France.
(3)INSERM, LNC UMR 866, Laboratoire d'Excellence LipSTIC, Dijon 21079, France.
Equipe "Heat Shock Proteins" Labellisée par la Ligue Nationale contre le Cancer,
Dijon 21079, France. Faculty of Medicine and Pharmacy of Dijon, Université
Bourgogne Franche-Comté, Dijon 21079, France. Service de Pneumologie et Soins
Intensifs Respiratoires, Centre Hospitalier Universitaire (CHU), Dijon 21079,
France.
(4)Institut des Biomolécules Max Mousseron, Faculty of Pharmacy, University of
Montpellier, Montpellier 34093, France.
(5)Department of Biochemistry, University of Monastir, Monastir 5000, Tunisia.
(6)INSERM, LNC UMR 866, Laboratoire d'Excellence LipSTIC, Dijon 21079, France.
Equipe "Heat Shock Proteins" Labellisée par la Ligue Nationale contre le Cancer,
Dijon 21079, France. Faculty of Medicine and Pharmacy of Dijon, Université
Bourgogne Franche-Comté, Dijon 21079, France. Anticancer Centre Georges François
Leclerc, CGFL, Dijon 21079, France.
(7)INSERM, LNC UMR 866, Laboratoire d'Excellence LipSTIC, Dijon 21079, France.
Equipe "Heat Shock Proteins" Labellisée par la Ligue Nationale contre le Cancer,
Dijon 21079, France. Faculty of Medicine and Pharmacy of Dijon, Université
Bourgogne Franche-Comté, Dijon 21079, France. Service de Pneumologie et Soins
Intensifs Respiratoires, Centre Hospitalier Universitaire (CHU), Dijon 21079,
France. [email protected]. Hodgkin's lymphoma is one of the curable cancers and the standard treatment
regimen involves combination chemotherapy involving bleomycin. One of the fatal
side effect of bleomycin is pulmonary toxicity. Here we present three cases of
Hodgkin's lymphoma treated with ABVD chemotherapy who had pulmonary toxicity.
All three developed bleomycin induced pulmonary toxicity in the form of
pulmonary fibrosis during treatment of the disease. Mode of treatment, severity
of the condition and the treatment outcome varied among the three. Two recovered
following treatment and one patient died due to irreversible pulmonary damage.
Causality assessment using Naranjo's scale gave a score of 7 for case one and
three and a score of 6 for case two, both indicating the adverse drug reaction
to be a probable bleomycin induced Lung fibrosis. Pulmonary toxicity is a devastating complication of bleomycin chemotherapy. This
insult is likely exacerbated by the free radical injury induced by high inspired
oxygen content, which is required to support these patients. Traditional
treatment consists of high-dose corticosteroids. We report the case of a
45-year-old man who developed bleomycin pulmonary toxicity, which failed to
respond to treatment with high-dose corticosteroids. We used protective
mechanical ventilatory settings while supported on veno-venous extracorporeal
membrane oxygenation using a bicaval dual-lumen, single cannula system to allow
for lung recovery. This case demonstrates the feasibility of using veno-venous
extracorporeal membrane oxygenation to treat bleomycin pulmonary toxicity in a
patient who has failed traditional therapy. Bleomycin is an antineoplastic agent causing fatal pulmonary toxicity. Early
diagnosis of bleomycin-induced pneumonitis is crucial to prevent irreversible
damage. Pulmonary function tests are unreliable for identifying risk of
bleomycin toxicity. Fluorodeoxyglucose PET/CT scanning can reveal inflammation
secondary to pneumonitis but is not sufficiently specific for diagnosis. We
retrospectively analyzed scans from 77 patients with Hodgkin lymphoma (median
age 41 years, mean bleomycin dose 134 mg) to evaluate bleomycin-induced
pneumonitis. We identified 13 patients with abnormal lung uptake of
fluorodeoxyglucose. Tracer activity was predomitly diffuse, bilateral, in the
lower lobes and subpleural areas. Interim scanning during treatment revealed
pneumonitis in eight of 13 patients (asymptomatic in six). One asymptomatic
patient died of bleomycin toxicity. For remaining 12 patients, bleomycin was
discontinued and methylprednisolone given, all showed resolution of the
pneumonitis. These findings suggest that routine interim or end-of-treatment
FDG-PET/CT scanning could be beneficial for alerting clinicians to asymptomatic
bleomycin-induced toxicity. Bleomycin has progressively been used to treat low-flow vascular malformations
in children. No significant systemic side effects have been reported in large
series after low doses, but some authors are still concerned about its use. We
report a case of a severe acute lung toxicity after a low dose of a second
bleomycin intralesional injection in a 5-year-old girl. She had no risk factors
and presented a cervical low-flow venous malformation. Twenty-four hours after
this second administration, she presented with fever and respiratory distress. A
chest radiograph showed bilateral opacities and computerized tomography revealed
extensive and diffuse lung ground-glass opacities. The patient started to
receive intravenous methylprednisolone, but she experienced progressively
increased dyspnea, and montelukast was added. She improved and was discharged
from the hospital without oxygen support, with montelukast and prednisolone for
tapering doses during months. Five months after onset, the patient is developing
well, is active, and walks and talks without dyspnea. A new low-dose computed
tomography shows improvement in radiologic findings. This is the second case of
pulmonary toxicity observed in a child after bleomycin intralesional
administration, and the first reported after the lowest dose of this drug to
date (7 mg: 0.28 mg/kg; 10 U: 0.4 U/kg). A delay in the diagnosis and treatment
of this complication can be fatal. Any physician who treats these patients must
be alert and consider this complication in children with respiratory symptoms
after bleomycin sclerotherapy. Early detection of pulmonary toxicity would allow
prompt therapy and could avoid pulmonary damage. Bleomycins are antitumor antibiotics that can chelate a metal center and cause
site-specific DNA cleavage at 5'-Gpyrimidine-3' regions of DNA. These
antibiotics are successful in the treatment of various cancers, but are known to
cause pulmonary fibrosis to patients under bleomycin regimes. Substantial
research has resulted in the development of over 300 bleomycin analogs, aiming
to improve the therapeutic index of the drug. Previous studies have proposed
that the lung toxicity caused by bleomycin is related to the C-terminal regions
of these drugs, which have been shown to closely interact with DNA in
metal-bleomycin-DNA complexes. Some of the research studying
metallo-bleomycin-DNA interactions have suggested three different binding modes
of the metal form of the drug to DNA, including total and/or partial
intercalation, and minor groove binding. However, there is still lack of
consensus regarding this matter, and solid conclusions on the subject have not
yet been established. Previously we investigated the diverse levels of
disruption caused to DNA hairpins containing 5'-GC-3' and 5'-GT-3' binding
sites, which are consequence of the binding of bleomycins with different
C-termini. The results of these investigation indicate that both the DNA-binding
site and the bleomycin C-termini have an impact on the final conformations of
drug and target. The present study focuses on the structural alterations
exhibited by Zn(II)bleomycin-A2, -B2, -A5 and Zn(II)peplomycin upon binding to
DNA hairpins containing 5'-GC-3' and 5'-GT-3' binding sites. Evidence that each
Zn(II)bleomycin is structurally affected depending on both its C-terminus and
the DNA-binding site present in the hairpin is provided. Bleomycin lung toxicity is well established and can manifest as
bleomycin-induced pneumonitis, but pneumomediastinum and pneumothorax are very
rare complications. We report the case of a 73-year-old woman, recently treated
with bleomycin for Hodgkin's disease, who was admitted for bleomycin-induced
pneumonitis. Two weeks later she had a pneumomediastinum with extensive
subcutaneous emphysema and small bilateral pneumothoraces. Three months after
that she was readmitted for dyspnoea. The CT scan showed complete regression of
the pneumomediastinum but extensive bilateral ground-glass infiltrates. The
patient died from respiratory failure 2 weeks later.
LEARNING POINTS: Respiratory investigation before initiation of bleomycin
treatment and then close follow-up during treatment of any abnormalities found
is mandatory, as bleomycin -induced toxicity can lead to fibrosis and secondary
pneumothorax/pneumomediastinum with high morbidity/mortality.Bleomycin-induce
pneumonitis (BIP) is managed with bleomycin discontinuation (Grade 1A) and
system corticosteroid (Grade 1B).Supplemental oxygen is discouraged for BIP, but
indicated for conservative management of pneumothoraces, so this case was
managed with limited oxygen supplementation (aiming for oxygen saturation of
92-94%). INTRODUCTION: Hodgkin's lymphoma (HL) is one of the most curable maligcies
with cure rates of above 85% across all stages. Bleomycin containing regimen is
routinely employed in the treatment of HL. Pulmonary toxicity due to this drug
is the most feared side effect in these regimens where the mortality rate is
approximately 2%-3%. We have conducted this study to assess the genetic
susceptibility among the Indian HL patients to bleomycin pulmonary toxicity
(BPT).
MATERIALS AND METHODS: In a retrospective study conducted at a tertiary care
hospital from South India between January 2013 and May 2019, we reviewed 100 HL
patients who were treated with bleomycin-containing regimen (adriamycin,
bleomycin, vinblastine, and dacarbazine or cyclophosphamide, vincristine,
procarbazine, and prednisone/adriamycin, bleomycin, and vinblastine) for BPT.
RESULTS: A total of 100 patients with HL who had received bleomycin-containing
regimen were analyzed, which included 23 females and 77 males. Twenty-nine
patients had BPT and five deaths were attributed to the same. Radiology reports
showed that 15 patients had acute BPT and eight patients had chronic changes.
Four patients had rare findings of bleomycin-induced lung damage and computed
tomography of the chest could not be done for two patients, whose chest X-ray
showed features suggestive of BPT.
CONCLUSION: The incidence of bleomycin induced pulmonary toxicity and mortality
was significantly higher in our study compared to that of other Western studies.
This could be probably due to the increased susceptibility of the Indian
patients to bleomycin induced lung damage. In a highly curable cancer such as
HL, it is unacceptable to have such a high life-threating toxicity. Hence, an
alternative chemotherapy regimen without bleomycin is to be explored which would
prevent toxicity and hence the compromise on survival. BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a serious lung problem with
advancing and diffusive pulmonary fibrosis as the pathologic basis, and with
oxidative stress and inflammation as the key pathogenesis.
Glycyl-L-histidyl-l-lysine (GHK) is a tripeptide participating into wound
healing and regeneration. GHK-Cu complexes improve GHK bioavailability. Thus,
the current study aimed to explore the therapeutic role of GHK-Cu on bleomycin
(BLM)-induced pulmonary fibrosis in a mouse model.
METHODS: BLM (3 mg/kg) was administered via tracheal instillation (TI) to induce
a pulmonary fibrosis model in C57BL/6j mice 21 days after the challenge of BLM.
GHK-Cu was injected intraperitoneally (i.p.) at different dosage of 0.2, 2 and
20 μg/g/day in 0.5 ml PBS on alternate day. The histological changes,
inflammation response, the collagen deposition and epithelial-mesenchymal
transition (EMT) was evaluated in the lung tissue. EMT was evaluated by ɑ-SMA
and fibronectin expression in the lung tissue. NF-κB p65, Nrf2 and TGFβ1/Smad2/3
signalling pathways were detected by immunoblotting analysis.
RESULTS: GHK-Cu complex inhibited BLM-induced inflammatory and fibrotic
pathological changes, alleviated the inflammatory response in the BALF by
reducing the levels of the inflammatory cytokines, TNF-ɑ and IL-6 and the
activity of MPO as well as reduced collagen deposition. In addition, the GHK-Cu
treatment significantly reversed the MMP-9/TIMP-1 imbalance and partially
prevented EMT via Nrf2, NF-κB and TGFβ1 pathways, as well as Smad2/3
phosphorylation.
CONCLUSIONS: GHK-Cu presented a protective effect in BLM-induced inflammation
and oxidative stress by inhibiting EMT progression and suppressing TGFβ1/Smad2/3
signalling in pulmonary fibrosis. |
What is another name for bimagrumab | Bimagrumab also goes by the name BYM338. | OBJECTIVE: To assess the long-term safety and tolerability and to monitor
benefits of extended use of bimagrumab in individuals with sporadic inclusion
body myositis (sIBM) who completed a single-dose core study.
METHODS: In this multicenter, open-label extension study, 10 adults received
bimagrumab 10 mg/kg IV every 4 weeks up to 2 years (104 weeks). Safety (primary
endpoint) was assessed by recording adverse events (AEs). Clinical benefits were
assessed by changes from baseline in thigh muscle volume (TMV), lean body mass
(LBM), 6-minute walk distance (6MWD), handgrip, and quadriceps strength.
RESULTS: Participants had a mean age of 70.1 (SD 10.4) years. All participants
(n = 10) discontinued the treatment due to early termination of the study (n =
7) or AEs (n = 3; myocardial infarction, esophageal carcinoma, and dementia,
none of which were treatment related). The most common AEs were muscle spasms
and falls (both 9 of 10, 90%), followed by diarrhea (6 of 10, 60%) and acne and
skin eruption (both 5 of 10, 50%). At weeks 8 and 16, mean TMV increased from
baseline by 4.1% (SD 4.3%) and 4.5% (SD 6.3%). Mean LBM increased from baseline
and was sustained at 6.9% (SD 3.9%) at week 76. Means of 6MWD showed a
progressive decline from baseline to week 76, during which there was a modest
numerical increase in handgrip strength and no significant changes in quadriceps
strength.
CONCLUSIONS: Long-term treatment up to 2 years with bimagrumab had a good safety
profile and was well tolerated in individuals with sIBM. An increase in muscle
mass was noted on a group level; however, there was no evidence of clinical
improvement.
CLINICALTRIALSGOV IDENTIFIER: NCT02250443.
CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for
patients with sIBM, long-term bimagrumab treatment was safe and well tolerated
and did not lead to functional improvement. |
What is STATegra? | STATegra is a comprehensive multi-omics dataset of B-cell differentiation in mouse. It includes measurements from up to 10 different omics technologies applied to the same biological system, namely the well-studied mouse pre-B-cell differentiation. | Author information:
(1)Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de
Navarra (UPNA), IdiSNA, Pamplona, Spain.
(2)Unit of Computational Medicine, Department of Medicine, Solna, Center for
Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
(3)Science for Life Laboratory, Solna, Sweden.
(4)Department of Applied Statistics, Operations Research and Quality,
Universitat Politècnica de València, Valencia, Spain.
(5)MRC London Institute of Medical Sciences, Institute of Clinical Sciences,
Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK.
(6)Department of Developmental and Cell Biology and Center for Complex
Biological Systems, University of California, Irvine, CA, USA.
(7)Chromatin and Disease Group, Cancer Epigenetics and Biology Programme (PEBC),
Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de
Llobregat, Barcelona, Spain.
(8)Protein Analysis Unit, Biomedical Center, Ludwig Maximilian University of
Munich, Munich, Germany.
(9)Division of Analytical Biosciences, Leiden Academic Center for Drug Research,
Leiden University, Leiden, The Netherlands.
(10)Biomax Informatics AG, Planegg, Germany.
(11)Centre for Human Metabolomics, Faculty of Natural Sciences, North-West
University (Potchefstroom Campus), Potchefstroom, South Africa.
(12)Microbiology and Cell Science Department, Institute for Food and
Agricultural Research, Genetics Institute, University of Florida, Gainesville,
Florida, USA.
(13)Computer Science Department, University of Crete, Heraklion, Greece.
(14)Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia,
United States.
(15)Gnosis Data Analysis PC, Heraklion, Greece.
(16)QIAGEN Aarhus A/S, Silkeborgvej 2, 8000, Aarhus, Denmark.
(17)Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam,
The Netherlands.
(18)MRC London Institute of Medical Sciences, Institute of Clinical Sciences,
Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK.
[email protected].
(19)Unit of Computational Medicine, Department of Medicine, Solna, Center for
Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
[email protected].
(20)Science for Life Laboratory, Solna, Sweden. [email protected].
(21)Biological and Environmental Sciences and Engineering Division, Computer,
Electrical and Mathematical Sciences and Engineering Division, King Abdullah
University of Science and Technology, Thuwal, Saudi Arabia.
[email protected].
(22)Microbiology and Cell Science Department, Institute for Food and
Agricultural Research, Genetics Institute, University of Florida, Gainesville,
Florida, USA. [email protected]. |
What is the generic name of the Xofluza? | Baloxavir marboxi is the generic name of Xofluza. It is approved for influenza. | Baloxavir marboxil (Xofluza™; baloxavir) is an oral cap-dependent endonuclease
inhibitor that has been developed by Roche and Shionogi. The drug blocks
influenza virus proliferation by inhibiting the initiation of mRNA synthesis. In
February 2018, baloxavir received its first global approval in Japan for the
treatment of influenza A or B virus infections. Phase III development is
underway in the USA, EU and other countries for this indication. This article
summarized the milestones in the development of baloxavir leading to this first
global approval for influenza A or B virus infections. The number of global clinical trials including Japan is increasing but still
much lower than those including the USA and Europe. The regulatory requirements
for clinical trials have been harmonized among Japan, USA, and Europe, and the
quality of clinical trials is kept high in these regions. Xofluza (baloxavir
marboxil) for influenza approved in Japan under the SAKIGAKE Designation System
is a good example of clinical trials including Japan. To include Japan in more
global clinical trials, stakeholders should work more collaboratively, and
increase the perception that clinical trials can be conducted appropriately and
efficiently in Japan. Further measures for better management of clinical trials
should also be developed. These would ultimately lead to improved benefits for
patients with timely access to new drugs. For the first time in nearly 20 years there is a new class of antiviral drug for
influenza. The latest approved antiviral is baloxavir marboxil (trade name,
Xofluza) which targets the endonuclease function of the viral PA polymerase
subunit and prevents the transcription of viral mRNA. The most promising aspect
of this new drug is its pharmacology which allows for effective treatment of
influenza A or B virus infection with just a single dose. A clinical trial
showed greater reductions in viral loads with baloxavir marboxil treatment
compared with oseltamivir, although no difference in the time to alleviation of
symptoms between these two drugs. With this new class of influenza drug comes
exciting prospects for combination therapy with the neuraminidase inhibitors
which may help to abate concerns about the development of resistance. Seasonal influenza infections are associated with an estimated 250-500 000
deaths annually. Resistance to the antiviral M2 ion-channel inhibitors has
largely invalidated their clinical utility. Resistance to neuraminidase
inhibitors has also been observed in several influenza A virus (IAV) strains.
These data have prompted research on inhibitors that target the cap-snatching
endonuclease activity of the polymerase acidic protein (PA). Baloxavir marboxil
(Xofluza®), recently approved for clinical use, inhibits cap-snatching
endonuclease. Resistance to Xofluza® has been reported in both in vitro systems
and in the clinic. An X-ray crystallographic screening campaign of a fragment
library targeting IAV endonuclease identified
5-chloro-3-hydroxypyridin-2(1H)-one as a bimetal chelating agent at the active
site. We have reported the structure-activity relationships for
3-hydroxypyridin-2(1H)-ones and 3-hydroxyquinolin-2(1H)-ones as endonuclease
inhibitors. These studies identified two distinct binding modes associated with
inhibition of this enzyme that are influenced by the presence of substituents at
the 5- and 6-positions of 3-hydroxypyridin-2(1H)-ones. Herein we report the
structure-activity relationships associated with various para-substituted
5-phenyl derivatives of 6-(p-fluorophenyl)-3-hydroxypyridin-2(1H)-ones and the
effect of using naphthyl, benzyl, and naphthylmethyl groups as alternatives to
the p-fluorophenyl substituent on their activity as endonuclease inhibitors. Baloxavir marboxil (Xofluza), an antiviral flu treatment, has now been approved
to prevent influenza.Patients should avoid taking calcium, aluminum, or
magnesium products while receiving baloxavir as this will lead to a loss of
antiviral efficacy. The smallest of all the pathogens, viruses, have continuously been the foremost
strange microorganisms. Viral infections can cause extreme sicknesses as
evidenced by the HIV/AIDS widespread or the later Ebola or Zika episodes.
Apprehensive framework distortions are also regularly observed as consequences
of numerous viral infections. Besides, numerous viral infections are of
oncoviruses, which can trigger different types of cancer. Nearly every year, a
modern infectious species emerges, debilitating the world population with an
annihilating episode. Subsequently, there is a need to create antivirals to
combat such rising infections. From the discovery of the antiviral drug
Idoxuridine in 1962 to the revelation of Baloxavir marboxil (Xofluza) that was
approved by the FDA in 2018, the whole process and criteria of creating
antivirals have changed significantly. In this article, different auxiliary
science strategies are described that can serve as a referral for therapeutic
innovation. |
Is Keutel syndrome a common genetic disorder? | No, Keutel syndrome (OMIM 245150) is a very rare syndrome | Matrix gla protein (MGP) is a potent inhibitor of extracellular matrix (ECM)
mineralization. MGP-deficiency in humans leads to Keutel syndrome, a rare
genetic disease hallmarked by abnormal soft tissue calcification. MGP-deficient
(Mgp(-/-)) mice show progressive deposition of hydroxyapatite minerals in the
arterial walls and die within 2 months of age. The mechanism of
antimineralization function of MGP is not fully understood. We examined the
progression of vascular calcification and expression of several
chondrogenic/osteogenic markers in the thoracic aortas of Mgp(-/-) mice at
various ages. Although cells with chondrocyte-like morphology have been reported
in the calcified aorta, our gene expression data indicate that
chondrogenic/osteogenic markers are not upregulated in the arteries prior to the
initiation of calcification. Interestingly, arterial calcification in Mgp(-/-)
mice appears first in the elastic laminae. Considering the known mineral
scaffolding function of elastin (ELN), a major elastic lamina protein, we
hypothesize that elastin content in the laminae is a critical determit for
arterial calcification in Mgp(-/-) mice. To investigate this, we performed
micro-computed tomography (µCT) and histological analyses of the aortas of
Mgp(-/-);Eln(+/-) mice and show that elastin haploinsufficiency significantly
reduces arterial calcification in this strain. Our data suggest that MGP
deficiency leads to alterations of vascular ECM that may in turn initiate
arterial calcification. BACKGROUND: Keutel syndrome is a rare autosomal-recessive condition
characterized by abnormal cartilage calcification. Neuroimaging findings
associated with this condition have been randomly described in the literature.
OBJECTIVE: To systematically evaluate the neuroimaging findings in a series of
children with Keutel syndrome to broaden our base of knowledge.
MATERIALS AND METHODS: Four children with confirmed Keutel syndrome were
reviewed for the brain, head and neck imaging findings.
RESULTS: Three of the four children, all siblings, showed evidence of moyamoya
syndrome. All four siblings had pinna cartilage calcification.
CONCLUSION: We propose that Keutel syndrome be considered and included among the
secondary causes of moyamoya syndrome. In children with petrified auricle and
neurological symptoms, Keutel syndrome should be considered and brain MRI with
MRA is required. Tracheobronchial cartilage calcification is a rare finding in the pediatric
population. Keutel syndrome (OMIM 245150) is a very rare syndrome characterized
with diffuse calcification of cartilage, brachytelephalangia, pulmonary
stenosis, midline defects, stippled epiphysis in infancy, and hearing loss
accompanied by recurrent respiratory infections and asthma-like attacks. Here,
we present a 14-year-old patient who was followed up with the diagnosis of
asthma, but did not respond to appropriate asthma treatment. She was
subsequently diagnosed as having Keutel syndrome with cartilage calcification on
the tracheobranchial tree and auricula, atypical facial features, recurrent
otitis media, hearing loss, and recurrent asthma-like symptoms. |
Is fusobacterium associated with Lemierre's syndrome? | Lemierre's syndrome is a rare condition that results from oropharyngeal infection with the gram-negative, anaerobic Fusobacterium necrophorum. | The combination of acute pharyngotonsillitis, neck pain, fever, and pulmonary
septic emboli caused by Fusobacterium necrophorum in a healthy young person is
extremely rare. The entity was described by Lemierre in 1936 as a typical
syndrome easy to recognize and diagnose exclusively on clinical grounds. A case
of Lemierre's disease is reported, and 10 other cases found in the medical
literature are reviewed. Lemierre's syndrome, a systemic anaerobic infection caused by Fusobacterium
necrophorum, is characterized by an acute oropharyngeal infection, septic
thrombophlebitis of the internal jugular vein, sepsis, and multiple metastatic
infections. It commonly leads to septic arthritis and occasionally to
osteomyelitis. In the preantibiotic era, this infection was nearly universally
fatal. Today it still poses a potentially grave threat to the young patients
affected. Prompt recognition with appropriate debridement and antibiotic
treatment results in complete recovery in most cases. We report a case of
anaerobic septic arthritis and multifocal acute hematogenous osteomyelitis as
part of a classic presentation of Lemierre's syndrome. OBJECTIVE: To assess the apparent increase in the diagnosis of Lemierre syndrome
(LS) and other Fusobacterium necrophorum infections at a large children's
hospital. Infections with F necrophorum ranged from peritonsillar abscess to
potentially fatal LS. LS is an oropharyngeal infection characterized by septic
thrombophlebitis of head and neck veins, complicated by dissemination of septic
emboli to pulmonary and systemic sites.
METHODS: Review of the medical and laboratory records was conducted of all
patients who were seen at or admitted to the Children's Hospital of Wisconsin
with the diagnosis of LS and/or isolation of F necrophorum from a clinical
specimen between January 1995 and January 2002.
RESULTS: During the 7-year period of the study, there was an increase in the
isolation of F necrophorum from patients who were seen at Children's Hospital of
Wisconsin, as well as the number of cases of LS. There was 1 isolation of F
necrophorum from clinical specimens per year from 1996 to 1999, which increased
to 10 isolates of the organism from January 2000 to January 2002. During the
most recent period, January 2001-January 2002, 5 cases of LS were diagnosed, a
distinctive entity not recognized previously at the institution.
CONCLUSIONS: The cause for the recent increase in the number of serious
infections caused by F necrophorum infection diagnosed at our institution is
unclear but does not seem to be related to changes in microbiologic techniques
or patient demography. We speculate that it could be attributable, in part, to
alterations in antibiotic usage patterns in our region. Clinicians need to be
aware of the increasing clinical importance of F necrophorum infections and the
life-threatening nature of LS. Classical Lemierre's syndrome is characterized by severe sepsis with metastatic
abscess formation in young, previously fit people from a primary head or neck
focus. The causative organisms are the anaerobic fusobacteria, most commonly
Fusobacterium necrophorum. We describe the evaluation, therapeutic interventions
and management of a patient with Lemierre's syndrome who presented in septic
shock with multiple organ dysfunction. The patient required immediate
interventions including endotracheal intubation and mechanical ventilation,
fluid resuscitation, inotropic support, bilateral thoracostomy tube drainage of
empyemata and antimicrobial therapy. The unexpected isolation of Fusobacterium
necrophorum from blood cultures and empyema fluid necessitated a change of
antibiotic regime to provide anaerobic cover. The patient required 4 weeks of
intensive support including prolonged antimicrobial therapy, and after a further
2 weeks was discharged home from hospital. This case highlights the need to
raise the awareness of 'the forgotten disease': Lemierre's syndrome. Its
diagnosis may, as in this case, be confounded by a lack of symptoms of
pharyngitis at the time of presentation, and end-organ dysfunction associated
with severe sepsis, possibly suggesting an alternative source of infection. As
appropriate antibiotics reduce mortality dramatically, clinicians need to be
alert to Lemierre's syndrome and include it in the differential diagnosis in
young but otherwise healthy patients presenting with severe sepsis. INTRODUCTION: Like Fusobacterium necrophorum, Fusobacterium nucleatum is capable
causing Lemierre's syndrome. Various locations of venous thrombosis have been
described associated with Fusobacterium sp. septicemia.
EXEGESIS: We describe a 43-year old alcoholic patient with F.nucleatum
septicemia complicated with hepatic abscesses, middle hepatic venous thrombosis,
osteomyelitis and infiltrative pneumonia. A pancreatic prosthesis was the only
potentially identified infectious entrance.
CONCLUSION: Our patient showed an alternative presentation of Lemierre's
syndrome, a "digestive variant". To the best of our knowledge, this is the first
report of Fusobacterium septicemia associated with hepatic venous thrombosis.
This report is close to the cases of portal thrombosis and opens the clinical
sphere of the lemierre's syndrome, whose incidence is increasing. Fusobacteria are most often associated with the classic presentation of
Lemierre's syndrome consisting of a sore throat, internal jugular vein
thrombophlebitis, and septic emboli to the lungs. Unusual presentations due to
the causative organism, F. necrophorum, may occur. We present such a case
involving a 17-year-old male patient with pyomyositis and fasciitis due to
necrobacillosis. Fusobacterium spp. should be considered in the differential
diagnosis of cases involving sepsis syndrome and pyomyositis. We present a patient with an atypical presentation of Fusobacterium infection,
the genus responsible for Lemierre's syndrome. This syndrome, which often
affects healthy, young people and can be fatal if not recognized and treated
early, is defined as a history of recent oropharyngeal infection with clinical
or radiological evidence of internal jugular vein thrombosis and isolation of
anaerobic pathogens, mainly Fusobacterium necrophorum. The history,
presentation, investigations and management of the patient are described and
then contrasted with the existing literature surrounding Lemierre's syndrome,
once termed the 'forgotten disease'. We report an unusual case of Lemierre's syndrome due to a rare species of
Fusobacterium, that is, Fusobacterium nucleatum preceded by Mycoplasma
pneumoniae pharyngitis and followed later by Epstein-Barr virus infectious
mononucleosis. We present a case of a patient with Lemierre's syndrome caused by Fusobacterium
necrophorum who developed a right frontal lobe brain abscess. We summarise the
epidemiology, microbiology, pathogenesis, clinical presentation, diagnosis,
complications, therapy, and outcomes of Lemierre's syndrome. F necrophorum is
most commonly associated with Lemierre's syndrome: a septic thrombophlebitis of
the internal jugular vein. Patients usually present with an exudative
tonsillitis, sore throat, dysphagia, and unilateral neck pain. Diagnosis of
septic thrombophlebitis is best confirmed by obtaining a CT scan of the neck
with contrast. Complications of the disease include bacteraemia with septic
abscesses to the lungs, joints, liver, peritoneum, kidneys, and brain. Treatment
should include a prolonged course of intravenous beta-lactam antibiotic plus
metronidazole. Fusobacterium nucleatum is a gram-negative bacillius commonly found in
oropharynx and is traditionally associated with Lemierre syndrome, which is
characterized by history of recent oropharyngeal infection, internal jugular
vein thrombosis, and isolation of anaerobic pathogens, mainly Fuosobacterium
necrophorum. However, recent evidence indicated that F. nucleatum is also a
normal resident of human gut. Less than a dozen of case reports had linked F.
nucleatum to gastrointestinal variant of Lemierre syndrome with portal vein
thrombosis. However, F. nucleatum bacteremia-associated hepatic vein thrombosis
is very rare. We report a case of a 73-year-old man who had hepatic vein
thrombosis associated with F. nucleatum bacteremia, most likely from subclinical
primary infection affecting the lower gastrointestinal tract. The underlying
pathophysiology and treatment options are discussed here. With rapid increase in
reporting of Lemierre syndrome, this case deserves particular attention from
clinicians. Lemierre's syndrome is a rare clinical condition that generally develops
secondary to oropharyngeal infection caused by Fusobacterium necrophorum, which
is an anaerobic bacteria. A 62-year-old patient with diabetes mellitus presented
with internal jugular vein and sigmoid sinus-transverse sinus thrombophlebitis,
accompanying otitis media and mastoiditis that developed after an upper airway
infection. Interestingly, there were air bubbles in both the internal jugular
vein and transverse sinus. Vancomycin and meropenem were started and a right
radical mastoidectomy was performed. The patient's clinical picture completely
resolved in 14 days. High mortality and morbidity may be prevented with a prompt
diagnosis of Lemierre's syndrome. An invasive Fusobacterium infection may originate from an apparent routine
pharyngitis and lead to significant distant septic complications. Even without
internal jugular thrombosis, the same mechanism of disease exists, and
therefore, the same morbidity, prognosis, and treatments are applicable, hence
the suitable term incomplete Lemierre syndrome. We present a case of invasive
Fusobacterium infection that meets all criteria for Lemierre syndrome except
lacking internal jugular thrombosis. A review of the literature that forms the
diagnostic criteria for this syndrome and the rationale for our creating this
novel term is presented. This is a case report of Lemierre's syndrome, a septic thrombophlebitis of the
internal jugular vein (IJV) usually preceded by pharyngitis and bacteraemia with
an anaerobic organism. Fusobacterium necrophorum is aaerobic Gram-negative
bacillus and is the most common organism reported to cause Lemierre's syndrome
which usually occurs one to three weeks post pharyngitis or oropharyngeal
surgery. A 21-year-old patient presented with signs of sepsis and a history of
sore throat, fever, and tender cervical lymph nodes. Blood cultures grew F.
necrophorum and Computed Tomography (CT) showed a filling defect in the left
retromandibular vein and thrombosis in the left internal jugular vein (IJV)
consistent with Lemierre's syndrome. This is an uncommon condition which
normally occurs in young individuals and diagnosis is often delayed. Fusobacterium necrophorum is a non-spore-forming, obligate anaerobic,
filamentous, gramnegative bacillus that frequently colonizes the human oral
cavity, respiratory tract, and gastrointestinal tract. Fusobacterium species
have rarely been implicated in cases of gastrointestinal variant of Lemierre's
syndrome. We describe a case of F. necrophorum bacteremia associated with
suppurative porto-mesenteric vein thrombosis (PVT) following acute ruptured
appendicitis. In addition, we list the documented twelve cases of Fusobacterium
pylephlebitis. Recanalization of the porto-mesenteric veins and relief of the
extrahepatic portal hypertension were achieved with early empiric antibiotic and
local thrombolytic therapy. Our patient's case underscores the importance of
recognizing Fusobacterium bacteremia as a possible cause of suppurative PVT
after disruption of the gastrointestinal mucosa following an acute
intraabdominal infectious process. Early treatment of this condition using
anticoagulation and endovascular thrombolysis as adjunctive therapies may
prevent PVT complications. Fusobacterium necrophorum is a gram-negative anaerobic bacterium that is the
causative agent of the invasive disease Lemierre's syndrome. In addition, it is
also associated with peritonsillar abscess formation and otitis media in small
children. Recent research has shown that F. necrophorum may be involved in
pharyngotonsillitis especially in adolescent and young adults and that it may be
the second most common bacterial cause of pharyngotonsillitis after
Streptococcus pyogenes (Group A streptococci). Peritonsillar abscesses and
Lemierre's syndrome due to F. necrophorum are also found in this age group,
suggesting that they may be complications of F. necrophorum pharyngotonsillitis.
In this review we present the present knowledge about the role of F. necrophorum
in pharyngotonsillitis with special emphasis on the age distribution. We argue
that F. necrophorum is an important pathogen involved in pharyngotonsillitis in
the age group of 13-40 years of age and we urge clinical microbiology labs to
set up the appropriate techniques to be able to detect F. necrophorum from
throat swabs. Fusobacterium species are well described as the causative pathogen in Lemierre's
syndrome, a suppurative thrombophlebitis of the jugular vein. However, they are
less recognized for a unique variant of Lemierre's syndrome presenting with
invasive intraabdominal infection and associated portal vein thrombosis. We
describe a case of Fusobacterium nucleatum with hepatic abscess and septic
pylephlebitis. Lemierre's syndrome is a systemic complication commonly caused by oropharyngeal
infection by Fusobacterium species, which manifests itself as an internal
jugular vein thrombosis formation. It is a rare occurrence nowadays with the
availability of broad spectrum antibiotics for treatment. Most cases in the
literature presented with a life-threatening condition. We are reporting a case
of Lemierre's syndrome that presented with persistent neck pain and swelling,
initially diagnosed as cervical lymphadenitis. Fusobacterium necrophorum is a rare infection most notable for causing
Lemierre's syndrome. This consists of a primary oropharyngeal infection and
septic thrombophlebitis, and one or more metastatic focus. Prior to the
widespread use of antibiotics, Lemierre's syndrome commonly followed a rapidly
progressing course, with a high mortality. We describe a case of a previously
well 18-month-old boy who presented to the emergency department with a 3-week
history of progressive, right-sided, painful neck swelling and systemic sepsis.
He was initially treated conservatively with intravenous antibiotics, but
ultimately required surgical drainage. Lemierre's syndrome is a rare condition
with increasing incidence which can have significant adverse outcomes including
death. Early recognition and treatment are essential, but identifying Lemierre's
disease is challenging. Fusobacterium necrophorum plays a causal role in a rare and life-threatening
condition, Lemierre's syndrome. It is characterized by infection involving the
posterior compartment of the lateral pharyngeal space complicated by septic
suppurative thrombophlebitis of the internal jugular vein with F. necrophorum
bacteremia and metastatic abscesses, primarily to the lung and pulmonary septic
emboli. Herein, we present a very rare case of oropharyngeal infection
complicated by Lemierre's syndrome with characteristic septic emboli to the
lungs presenting as sore throat in a previously healthy patient. A 23-year-old
woman presented with sore throat and was found to be in sepsis and acute kidney
injury. She was found to have septic emboli in lung and Streptococcus anginosus
and F. necrophorum in blood. She was diagnosed with Lemierre's syndrome and
successfully treated with antibiotics. Lemierre's syndrome should be included in
the differential diagnosis in young patients who deteriorate in the setting of a
sore throat. If the suspicion is high, throat swabs from young patients with
nonstreptococcal group A tonsillitis should be cultured anaerobically on
selective medium to detect the presence of F. necrophorum. While clinicians of
the infectious disease team may be familiar with this condition other
departments including internal medicine and critical care team may less so.
Unless clinicians are aware of this syndrome, diagnosis and treatment can be
delayed leading to higher morbidity and mortality. Once coined the "Forgotten Disease," Lemierre's syndrome is a rare condition
that results from oropharyngeal infection with the gram-negative, anaerobic
Fusobacterium necrophorum. The typical progression of illness involves spread to
adjacent structures such as the internal jugular vein with resulting
thrombophlebitis. Septic emboli to distant sites are also a common sequela.
Here, we present a case of Lemierre's syndrome in a 20-year-old, otherwise
healthy, male. The patient presented with fever, sore throat, and dysphagia.
Imaging revealed peritonsillar multiloculated fluid collections and necrotizing
pneumonia with multiple pulmonary abscesses. The patient's hospital course was
complicated by the development of necrotizing fasciitis in his right lower leg,
which required incision and drainage with surgical washout. In addition to
systemic intravenous antibiotics and anticoagulation, he underwent multiple
thoracentesis procedures. The patient was ultimately transferred to a tertiary
care center due to persistent fevers and lung abscesses. This case highlights
the challenges of initial diagnosis, as well as the treatment choices faced by
the attending physicians. Lemierre syndrome is a life-threatening condition associated with infection by
obligate anaerobes residing in oropharyngeal mucosa. The most common organism
responsible is Fusobacterium necrophorum. We report a case in a 69-year-old
gentleman. The man with past medical history of hypertension, anxiety and
chronic alcohol abuse was brought in by his family for altered mental status and
fever. He had a complicated stay with septic shock on multiple pressors, his
blood cultures grew Fusobacterium necrophorum and neck ultrasound showed acute
thrombus of the right internal jugular vein (IJV). The patient had received
intravenous antibiotics throughout stay but had poor prognosis and eventually
expired after a complicated hospital stay. Lemierre syndrome is a rare syndrome
usually associated with an acute oropharyngeal infection due to anaerobic
bacteria leading to secondary septic thrombophlebitis of the internal jugular
vein. The characteristic clinical picture noticed is a hematogenous progression
to distant septic emboli. It is a life-threatening condition and a prompt
diagnosis is critical for preventing fatal consequences. The purpose of this
case report is to increase awareness about this clinical condition among medical
professionals. Lemierre's syndrome is a rare but life-threatening condition characterized by an
oropharyngeal infection typically secondary to Fusobacterium necrophorum
resulting in septic thrombophlebitis of the internal jugular vein. Streptococcus
intermedius is a particularly rare cause of Lemierre's syndrome with only a few
cases reported in the literature. Here we describe a rare case of Lemierre's
syndrome, caused by Streptococcus intermedius, likely secondary to an
odontogenic infection, found to have a cervical epidural abscess with
concomitant large retropharyngeal and prevertebral abscesses on presentation, in
whom the clinical course was further complicated by an extensive cerebral venous
sinus thrombosis. However, despite grave complications, early diagnosis and
appropriate emergency management including intravenous antibiotics and surgical
intervention led to a successful recovery, thus demonstrating that aggressive
measures can potentially lead to a favorable outcome. INTRODUCTION: Lemierre's syndrome is a rare but serious complication of an oral
infection mostly related to Fusobacterium necrophorum. This condition combines
jugular vein thrombosis and septic emboli to the lungs or other organs.
CASE PRESENTATION: We report here an original case of a pharyngeal abscess
complicated by Lemierre's syndrome in a young healthy male patient. Samples
taken from the pus of the pharyngeal abscess showed the presence of Gardnerella
vaginalis associated with Fusobacterium necrophorum. The patient was treated by
draining the abscess, antibiotic therapy and preventive anticoagulation for 1
month. The evolution was good with a resolution of the thrombosis.
CONCLUSIONS: This case highlights the need for bacterial identification to adapt
antibiotic therapy in Lemierre's syndrome. It also shows the possibility of
extragenital localization of Gardnerella vaginalis in a male patient having oral
sex with women. In contrast to sexually transmitted infections such as syphilis
and pharyngeal gonococcus, this oral localization of Gardnerella vaginalis has
not been described previously in the literature. Author information:
(1)Division of Infection Medicine, Department for Clinical Sciences Lund,
Medical Faculty, Lund University, Lund, Sweden. Electronic address:
[email protected].
(2)Division of Infection Medicine, Department for Clinical Sciences Lund,
Medical Faculty, Lund University, Lund, Sweden; Clinical Microbiology,
Labmedicin, Region Skåne, Lund, Sweden.
(3)Division of Infection Medicine, Department for Clinical Sciences Lund,
Medical Faculty, Lund University, Lund, Sweden. |
What is the synonym of MK-1602? | MK-1602 is also named Ubrogepant. | Ubrogepant (MK-1602) is a novel, oral, calcitonin gene-related peptide receptor
antagonist in clinical development with positive phase III outcomes for acute
treatment of migraine. This paper describes the population exposure-response
(E-R) modeling and simulations, which were used to inform the phase III
dose-selection rationale, based on ~ 800 participants pooled across two phase
IIb randomized dose-finding clinical trials. The E-R model describes the placebo
and ubrogepant treatment effects based on migraine pain end points (2-hour pain
relief and 2-hour pain freedom) at various dose levels. Sensitivity analyses
were conducted to evaluate various assumptions of placebo response in light of
the high placebo response observed in one phase II trial. A population
pharmacokinetic model describing the effect of formulations was included in the
E-R simulation framework to assess potential dose implications of a formulation
switch from phase II to phase III. Model-based simulations predict that a dose
of 25 mg or higher is likely to achieve significantly better efficacy than
placebo with desirable efficacy levels. The understanding of E-R helped support
the dose selection for the phase III clinical trials. |
How many families did the 100,000 Genomes Pilot enrol? | The U.K. 100,000 Genomes Project is in the process of investigating the role of genome sequencing in patients with undiagnosed rare diseases after usual care and the alignment of this research with health care implementation in the U.K. National Health Service. Other parts of this project focus on patients with cancer and infection. A pilot study was conducted involving 4660 participants from 2183 families, among whom 161 disorders covering a broad spectrum of rare diseases were present. | Author information:
(1)From Genomics England (D.S., K.R.S., A.M., E.A.T., E.M.M., A.T., G.C., K.I.,
L.M., M. Wielscher, A.N., M. Bale, E.B., C.B., H.B., M. Bleda, A. Devereau,
D.H., E. Haraldsdottir, Z.H., D.K., C. Patch, D.P., A.M., R. Sultana, M.R.,
A.L.T.T., C. Tregidgo, C. Turnbull, M. Welland, S. Wood, C.S., E.W., S.L.,
R.E.F., L.C.D., O.N., I.U.S.L., C.F.W., J.C., R.H.S., T.F., A.R., M.C.), the
William Harvey Research Institute, Queen Mary University of London (D.S.,
K.R.S., V.C., A.T., L.M., M.R.B., D.K., S. Wood, P.C., J.O.J., T.F., M.C.),
University College London (UCL) Institute of Ophthalmology (V.C., G.A., M.M.,
A.T.M., S. Malka, N.P., P.Y.-W.-M., A.R.W.), UCL Genetics Institute (V.C.,
N.W.W.), GOSgene (H.J.W.), Genetics and Genomic Medicine Programme (L.V., M.R.,
M.D., L.C., P. Beales, M.B.-G.), National Institute for Health Research (NIHR)
Great Ormond Street Hospital Biomedical Research Centre (BRC) (M.R., S.
Grunewald, S.C.-L., F.M., C. Pilkington, L.R.W., L.C., P. Beales, M.B.-G.),
Infection, Immunity, and Inflammation Research and Teaching Department (P.A.,
L.R.W.), Stem Cells and Regenerative Medicine (N.T.), and Mitochondrial Research
Group (S. Rahman), UCL Great Ormond Street Institute of Child Health, UCL Ear
Institute (L.V.), the Department of Renal Medicine (D. Bockenhauer), and
Institute of Cardiovascular Science (P.E.), UCL, Moorfields Eye Hospital
National Health Service (NHS) Foundation Trust (V.C., G.A., M.M., A.T.M., S.
Malka, N.P., A.R.W.), the National Hospital for Neurology and Neurosurgery
(J.V., E.O., J.Y., K. Newland, H.R.M., J.P., N.W.W., H.H.), the Metabolic Unit
(L.A., S. Grunewald, S. Rahman), London Centre for Paediatric Endocrinology and
Diabetes (M.D.), and the Department of Gastroenterology (N.T.), Great Ormond
Street Hospital for Children NHS Foundation Trust (L.V., D. Bockenhauer, A.
Broomfield, M.A.C., T. Lam, E.F., V.G., S.C.-L., F.M., C. Pilkington, R.
Quinlivan, C.W., L.R.W., A. Worth, L.C., P. Beales, M.B.-G., R.H.S.), the
Clinical Genetics Department (M.R., T.B., C. Compton, C.D., E. Haque, L.I.,
D.J., S. Mohammed, L.R., S. Rose, D.R., G.S., A.C.S., F.F., M.I.) and St. John's
Institute of Dermatology (H.F., R. Sarkany), Guy's and St. Thomas' NHS
Foundation Trust, the Division of Genetics and Epidemiology, Institute of Cancer
Research (C. Turnbull), Florence Nightingale Faculty of Nursing, Midwifery, and
Palliative Care (T.B.), Division of Genetics and Molecular Medicine (M.A.S.),
and Division of Medical and Molecular Genetics (M.I.), King's College London,
NIHR BRC at Moorfields Eye Hospital (P.Y.-W.-M.), NHS England and NHS
Improvement, Skipton House (V.D., A. Douglas, S. Hill), and Imperial College
Healthcare NHS Trust, Hammersmith Hospital (K. Naresh), London, Open Targets and
European Molecular Biology Laboratory-European Bioinformatics Institute,
Wellcome Genome Campus, Hinxton (E.M.M.), the Division of Evolution and Genomic
Sciences, Faculty of Biology, Medicine, and Health, University of Manchester
(J.M.E., S.B., J.C.-S., S.D., G.H., H.B.T., R.T.O., G. Black, W.N.), and the
Manchester Centre for Genomic Medicine, St. Mary's Hospital, Manchester
University NHS Foundation Trust (J.M.E., Z.H., S.B., J.C.-S., S.D., G.H., G.
Black, W.N.), Manchester, the Department of Genetic and Genomic Medicine,
Institute of Medical Genetics, Cardiff University, Cardiff (H.J.W.), the
Department of Clinical Neurosciences (T.R., W.W., R.H., P.F.C.), the Medical
Research Council (MRC) Mitochondrial Biology Unit (T.R., W.W., P.Y.-W.-M.,
P.F.C.), the Department of Paediatrics (T.R.), the Department of Haematology
(K.S., C. Penkett, S. Gräf, R.M., W.H.O., A.R.), the School of Clinical Medicine
(K.R., E.L., R.A.F., K.P., F.L.R.), the Department of Medicine (S. Gräf), and
Cambridge Centre for Brain Repair, Department of Clinical Neurosciences
(P.Y.-W.-M.), University of Cambridge, NIHR BioResource, Cambridge University
Hospitals (K.S., S.A., R.J., C. Penkett, E.D., S. Gräf, R.M., M.K., J.R.B.,
P.F.C., W.H.O., F.L.R.), and Addenbrooke's Hospital, Cambridge University
Hospitals NHS Foundation Trust (G.F., P.T., O.S.-B., S. Halsall, K.P., A.
Wagner, S.G.M., N.B., M.K.), Cambridge Biomedical Campus, Wellcome-MRC Institute
of Metabolic Science and NIHR Cambridge BRC (M.G.), Congenica (A.H., H.S.),
Illumina Cambridge (A. Wolejko, B.H., G. Burns, S. Hunter, R.J.G., S.J.H., D.
Bentley), NHS Blood and Transplant (W.H.O.), and Wellcome Sanger Institute
(W.H.O.), Cambridge, the Health Economics Research Centre (J. Bucha, S.
Wordsworth) and the Wellcome Centre for Human Genetics (C. Camps, J.C.T.),
University of Oxford, NIHR Oxford BRC (J. Bucha, S. Wordsworth, J.D., C.
Crichton, J.W., K.W., C. Camps, S.P., N.B.A.R., A.S., J.T., J.C.T.), the Oxford
Centre for Genomic Medicine (A. de Burca, A.H.N.), and the Departments of
Haematology (N.B.A.R.) and Neurology (A.S.), Oxford University Hospitals NHS
Foundation Trust, Oxford Genetics Laboratories, Oxford University Hospitals NHS
Foundation Trust, Churchill Hospital (C. Campbell, K.G., T. Lester, J.T.), the
MRC Weatherall Institute of Molecular Medicine (N.K., N.B.A.R., A.O.M.W.) and
the Oxford Epilepsy Research Group (A.S.), Nuffield Department of Clinical
Neurosciences (A.H.N.), University of Oxford, and the Department of Clinical
Immunology (S.P.), John Radcliffe Hospital, Oxford, Peninsula Clinical Genetics
Service, Royal Devon and Exeter NHS Foundation Trust (E.B.), and the University
of Exeter Medical School (E.B., C.F.W.), Royal Devon and Exeter Hospital (S.E.),
Exeter, Newcastle Eye Centre, Royal Victoria Infirmary (A.C.B.), the Institute
of Genetic Medicine, Newcastle University, International Centre for Life (V.S.,
P. Bren), Wellcome Centre for Mitochondrial Research, Translational and
Clinical Research Institute, Faculty of Medical Sciences, Newcastle University
(G.S.G., R.H., A.M.S., D.M.T., R. Quinton, R.M., R.W.T., J.A.S.), Highly
Specialised Mitochondrial Service (G.S.G., A.M.S., D.M.T., R.M., R.W.T.) and
Northern Genetics Service (J. Burn), Newcastle upon Tyne Hospitals NHS
Foundation Trust (J.A.S.), and NIHR Newcastle BRC (G.S.G., D.M.T., J.A.S.),
Newcastle upon Tyne, the Institute of Cancer and Genomic Sciences, Institute of
Biomedical Research, University of Birmingham (C. Palles), and Birmingham
Women's Hospital (D.M.), Birmingham, the Genomic Informatics Group (E.G.S.),
University Hospital Southampton (I.K.T.), and the University of Southampton
(I.K.T.), Southampton, Liverpool Women's NHS Foundation Trust, Liverpool (A.
Douglas), the School of Cellular and Molecular Medicine, University of Bristol,
Bristol (A.D.M.), and Yorkshire and Humber, Sheffield Children's Hospital,
Sheffield (G.W.) - all in the United Kingdom; Fabric Genomics, Oakland (M.
Babcock, M.G.R.), and the Ophthalmology Department, University of California,
San Francisco School of Medicine, San Francisco (A.T.M.) - both in California;
the Jackson Laboratory for Genomic Medicine, Farmington, CT (P.N.R.); and the
Center for Genome Research and Biocomputing, Environmental and Molecular
Toxicology, Oregon State University, Corvallis (M.H.). |
What is CIS43LS? | CIS43LS is an antimalarial monoclonal antibody with an extended half-life against infection with Plasmodium falciparum. | CIS43 is a potent neutralizing human mAb that targets a highly conserved
"junctional" epitope in the Plasmodium falciparum (Pf) circumsporozoite protein
(PfCSP). Enhancing the durability of CIS43 in vivo will be important for
clinical translation. Here, 2 approaches were used to improve the durability of
CIS43 in vivo while maintaining potent neutralization. First, the Fc domain was
modified with the LS mutations (CIS43LS) to increase CIS43 binding affinity for
the neonatal Fc receptor (FcRn). CIS43LS and CIS43 showed comparable in vivo
protective efficacy. CIS43LS had 9- to 13-fold increased binding affinity for
human (6.2 nM versus 54.2 nM) and rhesus (25.1 nM versus 325.8 nM) FcRn at
endosomal pH 6.0 compared with CIS43. Importantly, the half-life of CIS43LS in
rhesus macaques increased from 22 days to 39 days compared with CIS43. The
second approach for sustaining antibody levels of CIS43 in vivo is through
adeno-associated virus (AAV) expression. Mice administered once with
AAV-expressing CIS43 had sustained antibody levels of approximately 300 μg/mL
and mediated protection against sequential malaria challenges up to 36 weeks.
Based on these data, CIS43LS has advanced to phase I clinical trials, and AAV
delivery provides a potential next-generation approach for malaria prevention. BACKGROUND: Additional interventions are needed to reduce the morbidity and
mortality caused by malaria.
METHODS: We conducted a two-part, phase 1 clinical trial to assess the safety
and pharmacokinetics of CIS43LS, an antimalarial monoclonal antibody with an
extended half-life, and its efficacy against infection with Plasmodium
falciparum. Part A of the trial assessed the safety, initial side-effect
profile, and pharmacokinetics of CIS43LS in healthy adults who had never had
malaria. Participants received CIS43LS subcutaneously or intravenously at one of
three escalating dose levels. A subgroup of participants from Part A continued
to Part B, and some received a second CIS43LS infusion. Additional participants
were enrolled in Part B and received CIS43LS intravenously. To assess the
protective efficacy of CIS43LS, some participants underwent controlled human
malaria infection in which they were exposed to mosquitoes carrying P.
falciparum sporozoites 4 to 36 weeks after administration of CIS43LS.
RESULTS: A total of 25 participants received CIS43LS at a dose of 5 mg per
kilogram of body weight, 20 mg per kilogram, or 40 mg per kilogram, and 4 of the
25 participants received a second dose (20 mg per kilogram regardless of initial
dose). No safety concerns were identified. We observed dose-dependent increases
in CIS43LS serum concentrations, with a half-life of 56 days. None of the 9
participants who received CIS43LS, as compared with 5 of 6 control participants
who did not receive CIS43LS, had parasitemia according to
polymerase-chain-reaction testing through 21 days after controlled human malaria
infection. Two participants who received 40 mg per kilogram of CIS43LS and
underwent controlled human malaria infection approximately 36 weeks later had no
parasitemia, with serum concentrations of CIS43LS of 46 and 57 μg per milliliter
at the time of controlled human malaria infection.
CONCLUSIONS: Among adults who had never had malaria infection or vaccination,
administration of the long-acting monoclonal antibody CIS43LS prevented malaria
after controlled infection. (Funded by the National Institute of Allergy and
Infectious Diseases; VRC 612 ClinicalTrials.gov number, NCT04206332.). Malaria affects more than 3 billion people in 95 countries, with an estimated
mortality rate of 400,000 per year. The female Anopheles spp mosquito most
commonly transmits malaria, and the main burden of disease is due to Plasmodium
falciparum. The most abundant antigen on the sporozoite surface is the
Plasmodium falciparum circumsporozoite protein (PfCSP). PfCSP is required for
parasite development and attachment to host hepatocytes. The first potential
protein vaccine, RTS,S/ASO1, consists of a recombit fusion antigen based on
PfCSP. Initial findings from a phase 3 trial of RTS,S/ASO1 were promising but
resulted in recommendations for further evaluation in large-scale trials. R21, a
circumsporozoite protein-based vaccine, combined with an adjuvant, Matrix-M
(MM), was recently evaluated in a phase 2 investigational study in children
between 5-17 months of age in Burkina Faso. The R21/MM candidate vaccine
resulted in high titers of malaria-specific antibodies. On August 26, 2021, the
findings from a phase 1 trial on a new monoclonal antibody to PfCSP, CIS43LS,
showed that a single dose of the CIS43LS monoclonal antibody resulted in
protection against malaria. These new findings have implications for the
seasonal control of malaria in endemic regions and a possible future role in
public health strategies to eliminate malaria. This Editorial aims to provide
the background to developing and evaluating the new malaria vaccines that target
PfCSP, including the first monoclonal antibody vaccine to malaria. |
List the main salt-inducible kinases. | SIK1
SIK2
SIK3
HDAC4
HDAC5 | Salt-inducible kinases (SIKs) represent a subfamily of AMPK family kinases. SIK1
has been shown to act as a mediator during the cellular adaptation to variations
in intracellular sodium in a variety of cell types. SIK2, as an isoform of the
SIK family, modulates various biological functions and acts as a signal
transmitter in various pathways. To evaluate the role of both SIK1 and SIK2
isoforms in blood pressure (BP), body fluid regulation and cardiac hypertrophy
development, we made use of constitutive sik1-/- (SIK1-KO), sik2-/- (SIK2-KO),
double sik1-/-sik2-/- (double SIK1*2-KO) knockout and wild-type (WT) mice
challenged to a standard (0.3% NaCl) or chronic high-salt (HS, 8% NaCl) diet
intake for 12 weeks.Mice, under a standard diet intake, had similar and normal
BP. On a chronic HS intake, SIK1-KO and double SIK1*2-KO mice showed increased
BP, but not WT and SIK2-KO mice. A chronic HS intake led to the development of
cardiac left ventricle hypertrophy (LVH) in normotensive WT and hypertensive
SIK1-KO mice, but not in SIK2-KO mice. Double SIK1*2-KO mice under standard diet
intake show normal BP but an increased LV mass. Remarkably, in response to a
dietary stress condition, there is an increase in BP but LVH remained unchanged
in double SIK1*2-KO mice.In summary, SIK1 isoform is required for maintaining
normal BP in response to HS intake. LVH triggered by HS intake requires SIK2
isoform and is independent of high BP. The salt-inducible kinases, SIK1, SIK2 and SIK3, most closely resemble the
AMP-activated protein kinase (AMPK) and other AMPK-related kinases, and like
these family members they require phosphorylation by LKB1 to be catalytically
active. However, unlike other AMPK-related kinases they are phosphorylated by
cyclic AMP-dependent protein kinase (PKA), which promotes their binding to
14-3-3 proteins and inactivation. The most well-established substrates of the
SIKs are the CREB-regulated transcriptional co-activators (CRTCs), and the Class
2a histone deacetylases (HDAC4/5/7/9). Phosphorylation by SIKs promotes the
translocation of CRTCs and Class 2a HDACs to the cytoplasm and their binding to
14-3-3s, preventing them from regulating their nuclear binding partners, the
transcription factors CREB and MEF2. This process is reversed by PKA-dependent
inactivation of the SIKs leading to dephosphorylation of CRTCs and Class 2a
HDACs and their re-entry into the nucleus. Through the reversible regulation of
these substrates and others that have not yet been identified, the SIKs regulate
many physiological processes ranging from innate immunity, circadian rhythms and
bone formation, to skin pigmentation and metabolism. This review summarises
current knowledge of the SIKs and the evidence underpinning these findings, and
discusses the therapeutic potential of SIK inhibitors for the treatment of
disease. Type 1 salt-inducible kinases (SIK1) has been shown to act as a mediator during
the cellular adaptation to variations in intracellular sodium in a variety of
cell types. Type 2 SIK (SIK2) modulates various biological functions and acts as
a signal transmitter in various pathways. To evaluate the role of both SIK
isoforms in renal and intestinal Na+,K+-ATPase (NKA) activity, we made use of
constitutive sik1-/- (SIK1-KO), sik2-/- (SIK2-KO), double sik1-/-sik2-/- (double
SIK1*2-KO) knockout and wild-type (WT) mice challenged to a standard (0.3% NaCl)
or chronic high-salt (HS, 8% NaCl) diet intake for 48 h or 12 weeks. Long-term
HS intake in WT was accompanied by 2-fold increase in jejunal NKA activity and
slight (~30% reduction) decreases in NKA in the ileum and cecum; none of these
changes was accompanied by changes in the expression of α1-NKA. The ablation of
SIK1 and SIK2 prevented the marked increase in jejunal NKA activity following
the long-term HS intake. The ablation of SIK1 and SIK2 in mice on a long-term HS
intake impacted differently in the ileum and cecum. The most interesting finding
is that in SIK2-KO mice marked reductions in NKA activity were observed in the
ileum and cecum when compared to WT mice, both on normal and long-term HS
intake. In summary, SIK1 or SIK2 ablation on chronic high-salt intake is
accompanied by modulation of NKA along the intestinal tract, which differ from
those after an acute high-salt intake, and this may represent an absorptive
compensatory mechanism to keep electrolyte homeostasis. The phase separation of the non-membrane bound Sec bodies occurs in Drosophila
S2 cells by coalescence of components of the endoplasmic reticulum (ER) exit
sites under the stress of amino acid starvation. Here, we address which
signaling pathways cause Sec body formation and find that two pathways are
critical. The first is the activation of the salt-inducible kinases (SIKs; SIK2
and SIK3) by Na+ stress, which, when it is strong, is sufficient. The second is
activation of IRE1 and PERK (also known as PEK in flies) downstream of ER stress
induced by the absence of amino acids, which needs to be combined with moderate
salt stress to induce Sec body formation. SIK, and IRE1 and PERK activation
appear to potentiate each other through the stimulation of the unfolded protein
response, a key parameter in Sec body formation. This work shows the role of
SIKs in phase transition and re-enforces the role of IRE1 and PERK as a
metabolic sensor for the level of circulating amino acids and salt. This article
has an associated First Person interview with the first author of the paper. |
Unlike DNA, RNA is not methylated, yes or no? | In addition to DNA methylation, reversible epigenetic modification occurring in RNA has been discovered recently. The most abundant type of RNA methylation is N6-methyladenosine (m6A) modification, which is dynamically regulated by methylases ("writers"), demethylases ("erasers") and m6A-binding proteins ("readers") | Parallel studies were performed with methionineless derivatives of Escherichia
coli 15 T(-) and Bacillus megaterium KM: T(-). Methylated bases are present in
the total cell ribonucleic acid (RNA) of B. megaterium. The level of RNA
methylation in E. coli is about 60% greater than that in B. megaterium. Although
E. coli deoxyribonucleic acid (DNA) was found to contain 0.12% 5-methylcytosine
(5-MC) and 0.24% 6-methylaminopurine (6-MA), methylated bases were not detected
in the DNA of B. megaterium. Assuming a molecular weight of 7 x 10(9) daltons
for B. megaterium DNA, it was calculated that this organism could not contain
more than one molecule of 5-MC or 6-MA per genome, and that possibly no
methylated bases were present. Methylated bases were also not detected in the
DNA of thymine-starved B. megaterium. Crude extracts of this organism possess
RNA methylase activity but no detectable DNA methylase activity. The sequence and the structure of DNA methyltransferase-2 (Dnmt2) bear close
affinities to authentic DNA cytosine methyltransferases. A combined genetic and
biochemical approach revealed that human DNMT2 did not methylate DNA but instead
methylated a small RNA; mass spectrometry showed that this RNA is aspartic acid
transfer RNA (tRNA(Asp)) and that DNMT2 specifically methylated cytosine 38 in
the anticodon loop. The function of DNMT2 is highly conserved, and human DNMT2
protein restored methylation in vitro to tRNA(Asp) from Dnmt2-deficient strains
of mouse, Arabidopsis thaliana, and Drosophila melanogaster in a manner that was
dependent on preexisting patterns of modified nucleosides. Indirect sequence
recognition is also a feature of eukaryotic DNA methyltransferases, which may
have arisen from a Dnmt2-like RNA methyltransferase. Although their amino acid sequences and structure closely resemble DNA
methyltransferases, Dnmt2 proteins were recently shown by Goll and colleagues to
function as RNA methyltransferases transferring a methyl group to the C5
position of C38 in tRNA(Asp). We observe that human DNMT2 methylates tRNA
isolated from Dnmt2 knock-out Drosophila melanogaster and Dictyostelium
discoideum. RNA extracted from wild type D. melanogaster was methylated to a
lower degree, but in the case of Dictyostelium, there was no difference in the
methylation of RNA isolated from wild-type and Dnmt2 knock-out strains.
Methylation of in vitro transcribed tRNA(Asp) confirms it to be a target of
DNMT2. Using site directed mutagenesis, we show here that the enzyme has a DNA
methyltransferase-like mechanism, because similar residues from motifs IV, VI,
and VIII are involved in catalysis as identified in DNA methyltransferases. In
addition, exchange of C292, which is located in a CFT motif conserved among
Dnmt2 proteins, strongly reduced the catalytic activity of DNMT2. Dnmt2
represents the first example of an RNA methyltransferase using a DNA
methyltransferase type of mechanism. The cytosine analogues azacytidine and decitabine are currently being developed
as drugs for epigenetic cancer therapy. Although various studies have shown that
both drugs are effective in inhibiting DNA methylation, it has also become clear
that their mode of action is not limited to DNA demethylation. Because
azacytidine is a ribonucleoside, the primary target of this drug may be cellular
RNA rather than DNA. We have now analyzed the possibility that azacytidine
inhibits the RNA methyltransferase DNMT2. We found that DNMT2 is variably
expressed in human cancer cell lines. RNA bisulfite sequencing showed that
azacytidine, but not decitabine, inhibits cytosine 38 methylation of tRNA(Asp),
a major substrate of DNMT2. Azacytidine caused a substantially stronger effect
than decitabine on the metabolic rate of all the cancer cell lines tested,
consistent with an effect of this drug on RNA metabolism. Of note, drug-induced
loss of RNA methylation seemed specific for DNMT2 target sites because we did
not observe any significant demethylation at sites known to be methylated by
other RNA methyltransferases. Our results uncover a novel and quantifiable drug
activity of azacytidine and raise the possibility that tRNA hypomethylation
might contribute to patient responses. The detection and quantification of methylated RNA can be beneficial to
understand certain cellular regulation processes such as transcriptional
modulation of gene expression, immune response, or epigenetic alterations.
Therefore, it is necessary to have methods available, which are extremely
sensitive and accurate, for instance liquid chromatography-tandem mass
spectrometry (LC-MS/MS). Here, we describe the preparation of RNA samples by
enzymatic hydrolysis and the subsequent analysis of ribonucleosides by LC-MS/MS
via NLS (Neutral loss scan) and DMRM (Dynamic multiple reaction monitoring).
Also, we provide variations of these methods including chromatographic
techniques and different kinds of quantification. |
What methodology does the Oncomine Dx target test use? | The Oncomine Dx target test uses the next generation sequencing methodology. | Author information:
(1)HM Sanchinarro University Hospital-CIBERONC, Madrid, Spain.
(2)HM Sanchinarro University Hospital, Madrid, Spain.
(3)La Paz University Hospital, Madrid, Spain.
(4)Ramon y Cajal University Hospital, IRYCIS and CIBERESP, Madrid, Spain.
(5)Germans Trias i Pujol University Hospital, Badalona, Spain.
(6)Catalan Institute of Oncology-Germans Trias i Pujol University Hospital,
Universitat Autònoma Barcelona (UAB), Badalona-Applied Research Group of
Oncology (B-ARGO), Badalona, Spain.
(7)General University Hospital-ISABIAL, Alicante, Spain.
(8)Institute of Health Research-Jimenez Diaz Foundation-CIBERONC, Madrid, Spain.
(9)Institute of Health Research-Jimenez Diaz Foundation, Madrid, Spain.
(10)Vall d'Hebron University Hospital, Barcelona, Spain.
(11)Quironsalud Hospital, Barcelona, Spain.
(12)La Fe University Hospital, Valencia, Spain.
(13)Clinico San Carlos University Hospital, Madrid, Spain.
(14)Puerta del Mar University Hospital, Cadiz, Spain.
(15)Clinico de Santiago University Hospital, Santiago De Compostela, Spain.
(16)Insular Materno-Infantil University Hospital Complex, Las Palmas de Gran
Canaria, Spain.
(17)Clinic Hospital, Barcelona, Spain.
(18)Alvaro Cunqueiro Hospital, Vigo, Spain.
(19)University of Navarra Clinic, Pamplona, Spain.
(20)Marques de Valdecilla University Hospital, Santander, Spain.
(21)Hospital del Mar, Barcelona, Spain.
(22)Clinico University Hospital, Valencia, Spain.
(23)Cruces University Hospital, Baracaldo, Spain.
(24)Miguel Servet University Hospital, Zaragoza, Spain.
(25)University Hospital of Gran Canaria Doctor Negrin, Las Palmas de Gran
Canaria, Spain.
(26)12 de Octubre University Hospital, Madrid, Spain.
(27)Ramon y Cajal University Hospital, Madrid, Spain.
(28)12 de Octubre University Hospital-CIBERONC, Madrid, Spain.
(29)Ramon y Cajal University Hospital-CIBERONC, Madrid, Spain.
(30)HM Sanchinarro University Hospital-CIBERONC, Madrid, Spain. Electronic
address: [email protected]. |
Describe the application of whole genome sequencing in the diagnosis of primary ciliary dyskinesia (PCD) | Genetic testing is an important component of diagnosing PCD, especially in cases of atypical disease history. WGS is effective in cases where prior gene panel testing has found no variants or only heterozygous variants. In these cases it may detect SVs and is a powerful tool for novel gene discovery. | BACKGROUND: It is estimated that 1-13% of cases of bronchiectasis in adults
globally are attributable to primary ciliary dyskinesia (PCD) but many adult
patients with bronchiectasis have not been investigated for PCD. PCD is a
disorder caused by mutations in genes required for motile cilium structure or
function, resulting in impaired mucociliary clearance. Symptoms appear in
infancy but diagnosis is often late or missed, often due to the lack of a "gold
standard" diagnostic tool and non-specific symptoms. Mutations in > 50 genes
account for around 70% of cases, with additional genes, and non-coding,
synonymous, missense changes or structural variants (SVs) in known genes
presumed to account for the missing heritability.
METHODS: UK patients with no identified genetic confirmation for the cause of
their PCD or bronchiectasis were eligible for whole genome sequencing (WGS) in
the Genomics England Ltd 100,000 Genomes Project. 21 PCD probands and 52
non-cystic fibrosis (CF) bronchiectasis probands were recruited in Wessex Genome
Medicine Centre (GMC). We carried out analysis of single nucleotide variants
(SNVs) and SVs in all families recruited in Wessex GMC.
RESULTS: 16/21 probands in the PCD cohort received confirmed (n = 9), probable
(n = 4) or possible (n = 3) diagnosis from WGS, although 13/16 of these could
have been picked up by current standard of care gene panel testing. In the other
cases, SVs were identified which were missed by panel testing. We identified
variants in novel PCD candidate genes (IFT140 and PLK4) in 2 probands in the PCD
cohort. 3/52 probands in the non-CF bronchiectasis cohort received a confirmed
(n = 2) or possible (n = 1) diagnosis of PCD. We identified variants in novel
PCD candidate genes (CFAP53 and CEP164) in 2 further probands in the non-CF
bronchiectasis cohort.
CONCLUSIONS: Genetic testing is an important component of diagnosing PCD,
especially in cases of atypical disease history. WGS is effective in cases where
prior gene panel testing has found no variants or only heterozygous variants. In
these cases it may detect SVs and is a powerful tool for novel gene discovery. |
Which CD38 antibody has been shown to be effective for Lupus Erythematosus? | Daratumumab, a human monoclonal antibody that targets CD38, has been used to treat Lupus Erythematosus. | Author information:
(1)From the Departments of Rheumatology and Clinical Immunology (L.O., P.G.,
R.B., U.S., G.B., F. Hiepe, T.A.), Nephrology and Internal Intensive Care Unit
(P.E.), Hematology, Oncology and Tumor Immunology (U.R.), and Cardiology and
Angiology, Campus Mitte (F.K.), Charité-Universitätsmedizin Berlin, corporate
member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin
Institute of Health (BIH), Deutsches Rheuma-Forschungszentrum (DRFZ) Institute
of the Leibniz Association (L.O., M.B., P.D., G.A.H., F. Heinrich, A.R., H.E.M.,
M.-F.M., F. Hiepe, T.A.), German Center for Cardiovascular Research (DZHK)
(F.K.), and BIH Brandenburg Center for Regenerative Therapies (BCRT),
Charité-Universitätsmedizin Berlin, corporate member of Freie Universität
Berlin, Humboldt-Universität zu Berlin (M.-F.M.) - all in Berlin; and the
Laboratory of Inflammation and Autoimmunity, Biomedical Research Foundation,
Academy of Athens, Athens (P.G.). Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease
characterized by multiple cellular and molecular dysfunctions of the innate and
adaptive immunity. Cytotoxic function of NK cells is compromised in patients
with SLE. Herein, we characterized the phenotypic alterations of SLE NK cells in
a comprehensive manner to further delineate the mechanisms underlying the
cytotoxic dysfunction of SLE NK cells and identify novel potential therapeutic
targets. Therefore, we examined PBMC from SLE patients and matched healthy
controls by single-cell mass cytometry to assess the phenotype of NK cells. In
addition, we evaluated the cell function of NK cells (degranulation and cytokine
production) and the killing of B cell subpopulations in a B cell-NK cell in
vitro co-culture model. We found that SLE NK cells expressed higher levels of
CD38 and were not able to adequately upregulate SLAMF1 and SLAMF7 following
activation. In addition, ligation of SLAMF7 with elotuzumab or of CD38 with
daratumumab on SLE NK cells enhanced degranulation of both healthy and SLE NK
cells and primed them to kill circulating plasma cells in an in vitro co-culture
system. Overall, our data indicated that dysregulated expression of CD38, SLAMF1
and SLAMF7 on SLE NK cells is associated with an altered interplay between SLE
NK cells and plasma cells, thus suggesting their contribution to the
accumulation of (auto)antibody producing cells. Accordingly, targeting SLAMF7
and CD38 may represent novel therapeutic approaches in SLE by enhancing NK cell
function and promoting elimination of circulating plasma cell. |
What is a circRNA? | Circular RNAs (circRNAs) are a new class of non-coding RNA with a stable structure formed by special loop splicing. | Circular RNAs (circRNA) have been reported as regulators involved in
hepatocellular carcinoma (HCC), but their mechanism of activity remains unknown.
This study performed quantitative reverse-transcription polymerase chain
reaction to determine if circNFATC3 was downregulated in 46 paired HCC tissues
and cell lines. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,
apoptotic, and transwell assay proved that circNFATC3 can inhibit hepatoma cell
proliferation, apoptosis, and migration/invasion in vitro. Mouse xenograft assay
demonstrated that circNFATC3 suppressed tumor size and weight and reduced lung
metastasis in vivo, and vice versa. The RNA-seq results showed that NFATC3
itself was the most significantly differentially expressed gene when circNFATC3
was manipulated, and bioinformatics and luciferase reporter assays verified
circNFATC3 regulated the expression of NFATC3 by interacting with the
hsa-miR-548I. Additionally, it was also indicated that the level of NFATC3 was
downregulated in HCC patients also and was significantly correlated with the
staging and prognosis of HCC. Moreover, both circNFATC3 and NFATC3 were shown to
inhibit the phosphorylation of JNK, c-Jun, AKT, and mTOR signaling pathways.
Overall, the circNFATC3 can sponge miR-548I to protect NFATC3 itself, then it
regulates hepatoma cell function via the JNK, c-Jun, AKT, and mTOR signaling
pathways, and the circNFATC3 can be a tumor-repressor on HCC. Recent technological advances in RNA sequencing and analysis have allowed an
increasingly thorough investigation of a previously unexplored class of
transcripts, circular (circ)RNAs. Accumulating evidence suggests that circRNAs
have unique functions which often rely on their association with microRNAs and
RNA-binding proteins. Through these interactions, circRNAs have been implicated
in major cellular processes and hence in the pathophysiology of a range of
diseases. Here, we provide guidelines to consider when developing studies on
circRNAs, including detecting and selecting the circRNAs, identifying their
binding partners and sites of interaction, modulating circRNA levels, assessing
copy numbers and stoichiometry, and addressing other points unique to circRNA
analysis. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches >
Regulatory RNAs. |
Summarize Fanconi's anemia | Fanconi anemia (FA) is a rare autosomal or X-linked genetic disorder characterized by chromosomal breakages, congenital abnormalities, bone marrow failure (BMF), and cancer. | Fanconi's anemia is an autosomal recessive disorder with a high incidence
(greater than 90%) of aplastic anemia and a premaligt component with a
greater than 10% risk of leukemia or solid tumors. The diagnosis of Fanconi's
anemia depends on increased chromosomal breakage in lymphocytes following
treatment with a DNA cross-linking agent; patients have been identified who are
clinically well and whose physical appearance is normal. Although bone marrow or
cord blood transplants can be curative, treatment for the aplastic anemia
usually depends on androgens. Close to 20 patients with Fanconi's anemia have
delivered normal babies, and the mothers' hematologic status was not
significantly adversely affected by the pregcy. A few patients have clonal
cytogenetic abnormalities in their bone marrow that do not necessarily indicate
leukemic transformation, but further follow-up is important. Studies of in vitro
erythropoiesis indicate a correlation between the clinical hematologic status
and the presence of erythroid progenitors in the blood or bone marrow. Certain
hematopoietic growth factors do increase growth in vitro, suggesting that new
types of therapy may become available. Not every patient has a poor prognosis.
There are now many adults with Fanconi's anemia, some with families of their
own. Fanconi's anaemia is a rare autosomal recessive disorder characterized by
progressive pancytopaenia and a cellular hypersensitivity to DNA crosslinking
agents. Four genetic complementation groups have been identified so far, and
here we use a functional complementation method to clone complementary DNAs that
correct the defect of group C cells. The cDNAs encode alternatively processed
transcripts of a new gene, designated FACC, which is mutated in group C
patients. The predicted FACC polypeptide does not contain any motifs common to
other proteins and so represents a new gene involved in the cellular response to
DNA damage. Fanconi's anemia, an inherited disorder characterized by bone marrow aplasia,
peripheral pancytopenia, and multiple congenital defects, has a association with
certain types of maligcies. These include acute myelomonocytic leukemia,
benign and maligt liver tumors, and squamous carcinomas of various organs. We
report a patient with esophageal carcinoma complicating Fanconi's anemia,
summarize the various tumors associated to date with the syndrome, and discuss
possible mechanisms of maligt transformation. This high incidence of
maligcy must be appreciated for early diagnosis and appropriate therapy. Fanconi anemia is a rare autosomal recessive disease characterized by bone
marrow failure, developmental anomalies, a high incidence of myelodysplasia and
acute nonlymphocytic leukemia, and cellular hypersensitivity to cross linking
agents. Five of the seven known Fanconi anemia proteins bind together in a
complex and influence the function of a sixth, FANCD2, which colocalizes with
BRCA1 in nuclear foci after genotoxic stress. Carboxy-terminal truncating
mutations of the seventh Fanconi anemia gene, BRCA2, are hypomorphic and lead to
FA-D1 and possibly FA-B. Because the Fanconi anemia alleles of BRCA2 fail to
bind to Rad51 in response to genotoxic stress and Rad51 therefore fails to
localize to nuclear damage foci, many investigators in the field suspect that
the Fanconi anemia pathway supports the integrity of the Rad51 and BRCA1 and
BRCA2 pathways as they function in homologous recombination repair. Because
these abnormalities are common to all somatic cells, it is unlikely that
dysfunction of this particular pathway results in tissue-specific apoptosis of
hematopoietic cells. Indeed, at least one of the Fanconi anemia proteins, FANCC,
exhibits functions in hematopoietic cells in addition to its role in the
complex. Because FANCC protects hematopoietic cells from apoptotic cues in ways
that do not require an intact heteromeric Fanconi anemia complex, it is
reasonable to expect that the other Fanconi anemia gene products will have
independent cytoplasmic and nuclear functions, particularly in hematopoietic and
germ cells that seem to rely so substantially on an intact portfolio of Fanconi
anemia proteins. Fanconi anemia (FA) is an autosomal recessive disorder that is defined by
cellular hypersensitivity to DNA cross-linking agents, and is characterized
clinically by developmental abnormalities, progressive bone-marrow failure, and
predisposition to leukemia and solid tumors. There is extensive genetic
heterogeneity, with at least 11 different FA complementation groups. FA-A is the
most common group, accounting for approximately 65% of all affected individuals.
The mutation spectrum of the FANCA gene, located on chromosome 16q24.3, is
highly heterogeneous. Here we summarize all sequence variations (mutations and
polymorphisms) in FANCA described in the literature and listed in the Fanconi
Anemia Mutation Database as of March 2004, and report 61 novel FANCA mutations
identified in FA patients registered in the International Fanconi Anemia
Registry (IFAR). Thirty-eight novel SNPs, previously unreported in the
literature or in dbSNP, were also identified. We studied the segregation of
common FANCA SNPs in FA families to generate haplotypes. We found that FANCA SNP
data are highly useful for carrier testing, prenatal diagnosis, and
preimplantation genetic diagnosis, particularly when the disease-causing
mutations are unknown. Twenty-two large genomic deletions were identified by
detection of apparent homozygosity for rare SNPs. In addition, a conserved SNP
haplotype block spanning at least 60 kb of the FANCA gene was identified in
individuals from various ethnic groups. Fanconi anemia (FA) is an autosomal recessive chromosomal instability disorder,
characterized by congenital anomalies, defective hematopoiesis and a high risk
of developing acute myeloid leukemia and certain solid tumors. All racial and
ethnic groups are at risk, and at least 11 complementation groups have been
identified and the genes defective in eight of these have been identified
(FANCA, C, D2, E, F, G, L and BRCA2). FA-A is the most common complementation
group, accounting for approximately 65% of all affected individuals. The
gold-standard screening test for FA is based on the characteristic
hypersensitivity of FA cells to the crosslinking agents, such as mitomicin C or
diepoxybutane. Recent progress has been made in identifying the genes bearing
pathogenetically relevant mutations, but slower progress has been made in
defining the precise functions of the proteins in normal cells, in part because
that the proteins are multifunctional. Molecular studies have established that a
common pathway exist, both between the FA proteins and other proteins involved
in DNA repair such as NBS1, ATM, BRCA1 and BRCA2. Stem cell transplantation
(SCT) is the only option for establishing normal hematopoiesis. To reduce undue
toxicities due to inherent hypersensitivity, nonmyeloablative conditioning for
transplants has been advocated. This review summarizes the general clinical and
hematologic features and the current management of FA. Fanconi anemia (FA) is
the commonest type of inherited bone marrow failure syndrome with the birth
incidence of around three per million. The inheritance pattern is autosomal
recessive with the estimated heterozygote frequency being one in 300 in Europe
and the US. Fanconi anemia is a rare inherited disease characterized by congenital
anomalies, growth retardation, aplastic anemia and an increased risk of acute
myeloid leukemia and squamous cell carcinomas. The disease is caused by mutation
in genes encoding proteins required for the Fanconi anemia pathway, a response
mechanism to replicative stress, including that caused by genotoxins that cause
DNA interstrand crosslinks. Defects in the Fanconi anemia pathway lead to
genomic instability and apoptosis of proliferating cells. To date, 13
complementation groups of Fanconi anemia were identified. Five of these genes
have been deleted or mutated in the mouse, as well as a sixth key regulatory
gene, to create mouse models of Fanconi anemia. This review summarizes the
phenotype of each of the Fanconi anemia mouse models and highlights how genetic
and interventional studies using the strains have yielded novel insight into
therapeutic strategies for Fanconi anemia and into how the Fanconi anemia
pathway protects against genomic instability. Fanconi anemia is a genetically heterogeneous disorder associated with
chromosome instability and a highly elevated risk for developing cancer. The
mutated genes encode proteins involved in the cellular response to DNA
replication stress. Fanconi anemia proteins are extensively connected with DNA
caretaker proteins, and appear to function as a hub for the coordination of DNA
repair with DNA replication and cell cycle progression. At a molecular level,
however, the raison d'être of Fanconi anemia proteins still remains largely
elusive. The thirteen Fanconi anemia proteins identified to date have not been
embraced into a single and defined biological process. To help put the Fanconi
anemia puzzle into perspective, we begin this review with a summary of the
strategies employed by prokaryotes and eukaryotes to tolerate obstacles to the
progression of replication forks. We then summarize what we know about Fanconi
anemia with an emphasis on biochemical aspects, and discuss how the Fanconi
anemia network, a late acquisition in evolution, may function to permit the
faithful and complete duplication of our very large vertebrate chromosomes. Fanconi's Anemia is primarily an autosomal recessive genetic disorder
characterized by congenital abnormalities, defective haematopoiesis leading to
bone marrow failure and increased risk of development of Myelodysplastic
syndrome, acute myeloid leukemia and solid tumours. Chromosomal instability can
be demonstrated by breakage caused by alkylating agents and forms the basis of
diagnosis. Our patient presented with structural deformities associated with
features of bone marrow failure in form of pancytopenia. Bone marrow analysis
and flow cytometry done on aspirate was suggestive of MDS. He subsequently
progressed to frank acute myeloid leukemia and succumbed to the illness. The
case is being reported for its rarity especially, Fanconi's Anemia associated
with monosomal karyotype (one monosomy plus one more structural abnormality). Fanconi's Anaemia is a rare autosomal recessive disease for which the incidence
of head and neck cancer can be increased 700-fold1. We report a case of a
31-year old Caucasian male with FA who initially presented in July 2007 with
oral squamous cell carcinoma for which he received radical surgery and
radiotherapy. He was disease-free until August 2015 when he presented with an
extremely aggressive recurrence. Fanconi anemia (FA) is an inherited bone marrow failure syndrome characterized
by multiple congenital abnormalities, progressive bone marrow failure, and a
predisposition to maligcies, resulting from mutations in one of the 22 known
FANC genes (from FANCA to FANCW). The proteins encoded by these genes
participate in a deoxyribonucleic acid interstrand cross-link repair pathway,
the so-called FA/BRCA pathway. The 22 FANC genes include hereditary breast and
ovarian cancer susceptibility genes, such as BRCA1 or BRCA2. Patients with FA
display a wide range of clinical phenotypes owing to the genetic heterogeneity
of the disease; therefore, the molecular diagnosis is critical for the
appropriate management of such patients. Recently, we successfully subtyped 97%
of the 117 Japanese patients with FA and identified 215 mutant alleles through a
comprehensive strategy. In this review, the characteristics of genetic subtyping
and mutated FANC gene variants in Japanese patients with FA and the
genotype-phenotype correlation in FA are summarized. In addition, the carrier
frequency of pathogenic FANC genes and risk of cancer among the FANC gene
mutation carriers in general Japanese population are discussed. Fanconi anemia (FA) is a rare inherited genetic condition that may lead to bone
marrow failure, leukemia, and/or solid tumors. It is caused by the loss of
function of at least 1 gene of the FA/BRCA pathway, which is necessary for DNA
repair. Patients with FA have a 200-fold to 1000-fold risk of developing head
and neck cancer, mainly oral squamous cell carcinoma (OSCC), and of doing so at
a much younger age than individuals within the general population. Also,
patients who have FA with OSCC have poor overall survival rates, reinforcing the
necessity to detect OSCC early. The scope of the current review is to provide an
update on OSCC in patients with FA. Fanconi anemia (FA) is a multisystem disease, characterized by the triad of
physical abnormalities, bone marrow failure, and increased risk for maligcy.
In the past few years, data has accumulated regarding fertility issues in FA
patients, mostly due to gonadal dysfunction, which is prevalent in FA patients
reaching puberty. It seems that attenuated FA phenotype lacking the classical
manifestations often is presented with POI or azoospermia. Searching the
literature, we summarized data regarding FA patients presenting as suffering
from sub/infertility due to gonadal dysfunction, with or without other FA
symptoms. We present a summary of the patients having biallelic pathogenic
variants in FA genes FANCA, FANCM, BRCA2, and XRCC2 that presented with gonadal
dysfunction with or without other phenotypic features of FA. Some were in
mosaic, while some are considered hypomorphic, enabling residual protein
function. There are also a few descriptions of POI associated with monoallelic
pathogenic variants in FANCA, BRCA2, and FANCL. We conclude that the diagnosis
of FA in gonadal dysfunction patients is of utmost importance due to its
actionability. Follow-up strategies in FA patients are designed to discover
early stages of leukemias and solid tumors and thus save lives. The feasibility
of next-generation sequencing (NGS) can now ease this diagnostic procedure. An
open question is the justification of performing NGS for all isolated
azoospermia/POI patients. Fanconi anemia is a rare disorder resulting from defects in genes responsible
for DNA damage responses. It is characterized by congenital anomalies, aplastic
anemia, and a predisposition to cancer. Currently, hematopoietic stem cell
transplant (HSCT) is the only curative treatment available for bone marrow
failure; however, HSCT increases oral squamous cell carcinoma (OSCC) risk. Here
we report the case of a patient diagnosed with Fanconi anemia in childhood who
was treated with HSCT and later diagnosed with multiple OSCCs during a 12-year
follow-up. Despite multiple surgical interventions and radiotherapy regimens,
the patient`s health deteriorated. Management of individuals with Fanconi anemia
is challenging and must be provided by a multidisciplinary healthcare team to
ensure better staging, treatment planning, and coordination. |
Which one of the CYP450 enzymes is the second most frequently implicated in the metabolism of the drugs currently available on the market? | CYP3A4 and CYP2D6 are the most relevant since they metabolize about 50% and 30% of the drugs on the market, respectively. | The use of medicinal plants concomitantly with conventional drugs can result in
herb-drug interactions that cause fluctuations in drug bioavailability and
consequent therapeutic failure and/or toxic effects. The CYP superfamily of
enzymes plays an important role in herb-drug interactions. Among CYP enzymes,
CYP3A4 and CYP2D6 are the most relevant since they metabolize about 50% and 30%
of the drugs on the market, respectively. Thus, the main goal of this study was
to evaluate the occurrence of in vitro interactions between medicinal plant
extracts and drug substrates of CYP3A4 and CYP2D6 enzymes. Standardized extracts
from nine medicinal plants (Bauhinia forficata, Cecropia glaziovii, Cimicifuga
racemosa, Cynara scolymus, Echinacea sp., Ginkgo biloba, Glycine max, Ilex
paraguariensis, and Matricaria recutita) were evaluated for their potential
interactions mediated by CYP3A4 and CYP2D6 enzymes. Among the extracts tested,
C. glaziovii (red embaúba) showed the most relevant inhibitory effects of CYP3A4
and CYP2D6 activity, while I. paraguariensis (yerba mate) inhibited CYP3A4
activity. Both extracts were chemically analyzed by UPLC-MS/MS, and these
inhibitory effects could lead to clinically potential and relevant interactions
with the drug substrates of these isoenzymes. |
Describe SBGNview | SBGNview is a tool set for pathway based data visalization | |
Which diseases can be treated with Itepekimab? | Itepekimab, a monoclonal antibody targeting IL-33, demonstrated clinical activity in asthma, with potential in chronic obstructive pulmonary disease (COPD). | Itepekimab is a monoclonal antibody that targets interleukin (IL-33) and has
been shown to reduce airway inflammation and associated tissue damage in
preclinical studies. We assessed the safety, tolerability, pharmacokinetics
(PKs), and pharmacodynamic profiles of single-ascending and multiple-ascending
doses of itepekimab in two randomized, double-blind, placebo-controlled phase I
studies. Healthy adults (N = 40) were randomized to the single-dose study and
patients with moderate asthma (N = 23) to the multiple-dose study. Itepekimab
was administered intravenously (0.3, 1, 3, or 10 mg/kg infusion) or
subcutaneously (150 mg) in the single-dose study and subcutaneously (75 or
150 mg weekly for 4 weeks) in the multiple-dose study. Itepekimab exhibited
linear PKs across studies and dose-proportional increases in mean maximum
concentration in serum and area under the concentration-time curve following
single intravenous or multiple subcutaneous doses. Itepekimab demonstrated mean
subcutaneous bioavailability of 59-73% and a long terminal half-life
(30.0-31.6 days). IL-33 concentrations in most healthy participants and patients
with asthma were undetectable at baseline. Following administration of
itepekimab in both studies, total IL-33 concentrations increased and blood
eosinophils decreased, both with durable effect. Itepekimab was well-tolerated
in both studies with no detection of treatment-emergent anti-drug antibody
responses. |
What is the msDNA? | msDNA is actually a complex of DNA, RNA, and probably protein. It is composed of a small, single-stranded DNA, linked to a small, single-stranded RNA molecule. The 5' end of the DNA molecule is joined to an internal guanosine residue of the RNA molecule by a unique 2'-5' phosphodiester bond. msDNA is produced in many hundreds of copies per cell, but its function remains unknown. | The multi-copy single-stranded DNA (msDNA) is yielded by the action of reverse
transcriptase of retro-element in a wide range of pathogenic bacteria. Upon this
phenomenon, it has been shown that msDNA is only produced by Eubacteria because
many Eubacteria species contained reverse transcriptase in their special
retro-element. We have screened around 111 Archaea at KEGG (Kyoto Encyclopedia
of Genes and Genomes) database available at genome net server and observed three
Methanosarcina species (M.acetivorans, M.barkeri and M.mazei), which also
contained reverse transcriptase in their genome sequences. This observation of
reverse transcriptase in Archaea raises questions regarding the origin of this
enzyme. The evolutionary relationship between these two domains of life
(Eubacteria and Archaea) hinges upon the phenomenon of retrons. Interestingly,
the evolutionary trees based on the reverse transcriptases (RTs) and 16S
ribosomal RNAs point out that all the Eubacteria RTs were descended from Archaea
RTs during their evolutionary times. In addition, we also have shown some
significant structural features among the newly identified msDNA-Yf79 in
Yersinia frederiksenii with other of its related msDNAs (msDNA-St85, msDNA-Vc95,
msDNA-Vp96, msDNA-Ec78 and msDNA-Ec83) from pathogenic bacteria. Together the
degree of sequence conservation among these msDNAs, the evolutionary trees and
the distribution of these ret (reverse transcriptase) genes suggest a possible
evolutionary scenario. The single common ancestor of the organisms of Eubacteria
and Archaea subgroups probably achieved this ret gene during their evolution
through the vertical descent rather than the horizontal transformations followed
by integration into this organism genome by a mechanism related to phage
recognition and/or transposition. |
Are Epoxyeicosatrienoic acids (EETs) synthesized by cytochrome P450 epoxygenases from arachidonic acid? | Epoxyeicosatrienoic acids (EETs) are fatty acid signaling molecules synthesized by cytochrome P450 epoxygenases from arachidonic acid | Microsomes prepared from COS-1 cells transiently expressing rabbit cytochromes
P450 2C1 and 2C2 catalyzed the metabolism of arachidonic acid to predomitly
11,12- and 14,15-epoxyeicosatrienoic acids (EETs) when microsomal epoxide
hydrolase activity was inhibited by 0.2 mM 1,2-epoxy-3,3,3-trichloropropane.
P450 2C2 catalyzed the formation of 11,12-EET and 14,15-EET at a ratio of 3.0
and also produced 19-hydroxyeicosatetraenoic acid (19-HETE). The 11,12-EET,
14,15-EET, and 19-HETE represented 48.3, 15.9, and 12.8%, respectively, of the
total metabolites formed. P450 2C1 produced a similar but distinct ratio of
11,12-EET to 14,15-EET (2.0) and did not produce any detectable 19-HETE. The
11,12-EET and 14,15-EET represented 63.0 and 31.1%, respectively, of the total
metabolites formed. The 8,9- and 5,6-EETs were not detected with either enzyme.
The ratio of the 11,12-EET to 14,15-EET was 1.5 with P450 2CAA, a P450
arachidonic acid epoxygenase (P450 2CAA) that had an amino-terminal sequence
identical to that of P450 2C2 [J. Biol. Chem. 267:5552-5559 (1992)]. P450 2C1,
2C2, and 2CAA metabolized lauric acid. The ratio of omega-1- to
omega-hydroxylated laurate was 3.6, 3.4, and 2.4 for P450 2CAA, P450 2C2, and
P450 2C1, respectively. Purified P450 2CAA had a slightly greater apparent
molecular weight than expressed P450 2C2 on sodium dodecyl
sulfate-polyacrylamide gels. The results clearly establish that rabbit P450 2C1
and 2C2 are arachidonic acid epoxygenases, and they suggest that P450 2CAA and
2C2 are very similar but may not be identical isoforms. Epoxyeicosatrienoic acids (EETs), the eicosanoid biomediators synthesized from
arachidonic acid by cytochrome P450 epoxygenases, are inactivated in many
tissues by conversion to dihydroxyeicosatrienoic acids (DHETs). However, we find
that human skin fibroblasts convert EETs mostly to chain-shortened epoxy-fatty
acids and produce only small amounts of DHETs. Comparative studies with
[5,6,8,9,11,12,14,15-(3)H]11,12-EET ([(3)H]11,12-EET) and [1-(14)C]11,12-EET
demonstrated that chain-shortened metabolites are formed by removal of carbons
from the carboxyl end of the EET. These metabolites accumulated primarily in the
medium, but small amounts also were incorporated into the cell lipids. The most
abundant 11, 12-EET product was 7,8-epoxyhexadecadienoic acid (7,8-epoxy-16:2),
and two of the others that were identified are 9, 10-epoxyoctadecadienoic acid
(9,10-epoxy-18:2) and 5, 6-epoxytetradecaenoic acid (5,6-epoxy-14:1). The main
epoxy-fatty acid produced from 14,15-EET was 10,11-epoxyhexadecadienoic acid
(10, 11-epoxy-16:2). [(3)H]8,9-EET was converted to a single metabolite with the
chromatographic properties of a 16-carbon epoxy-fatty acid, but we were not able
to identify this compound. Large amounts of the chain-shortened 11,12-EET
metabolites were produced by long-chain acyl CoA dehydrogenase-deficient
fibroblasts but not by Zellweger syndrome and acyl CoA oxidase-deficient
fibroblasts. We conclude that the chain-shortened epoxy-fatty acids are produced
primarily by peroxisomal beta-oxidation. This may serve as an alternate
mechanism for EET inactivation and removal from the tissues. However, it is
possible that the epoxy-fatty acid products may have metabolic or functional
effects and that the purpose of the beta-oxidation pathway is to generate these
products. Epoxyeicosatrienoic acids (EETs), which are synthesized from arachidonic acid by
cytochrome P450 epoxygenases, function primarily as autocrine and paracrine
effectors in the cardiovascular system and kidney. They modulate ion transport
and gene expression, producing vasorelaxation as well as anti-inflammatory and
pro-fibrinolytic effects. EETs are incorporated into the sn-2 position of
phospholipids and are rapidly mobilized when a cell is treated with a Ca(2+)
ionophore, suggesting that they may play a role in phospholipid-mediated signal
transduction processes. Soluble epoxide hydrolase (sEH) converts EETs to
dihydroxyeicosatrienoic acids (DHETs), and inhibition of sEH is a potential
approach for enhancing the biological activity of EETs. EETs also undergo
chain-elongation and beta-oxidation, and the accumulation of partial
beta-oxidation products increases when sEH is inhibited. Some functional effects
of EETs occur through activation of either the guanine nucleotide binding
protein Galphas or the Src signal transduction pathways, suggesting that EETs
act by binding to membrane receptors. However, other evidence indicates that the
modulation of gene expression occurs through an intracellular action of EETs.
Because of the diversity of biochemical and functional responses produced by
EETs, it is doubtful that a single mechanism or signal transduction pathway can
account for all of their actions. Arachidonic acid metabolites contribute to the regulation of vascular tone and
therefore tissue blood flow. The vascular endothelium metabolizes arachidonic
acid by cytochrome P450 epoxygenases to epoxyeicosatrienoic acids or EETs. The
placement of the epoxide group can occur on any of the double bonds of
arachidonic acid resulting in four EET regioisomers; 5,6-, 8,9-, 11,12- and
14,15-EET. In the vasculature, EETs are key components of cellular signaling
cascades that culminate in the activation of smooth muscle potassium channels to
induce membrane hyperpolarization and vascular relaxation. In some vasculatures
such as bovine coronary arteries, EET regioisomers are equipotent in inducing
relaxations, while in other arteries, a specific EET regioisomer induces
relaxation while others do not. Therefore, the position of the double bonds
and/or the epoxide group may alter vascular agonist activity. This observation
suggests that small alterations in the chemical structure of EETs can
significantly impact vascular activity. To explore this hypothesis, we
synthesized a series of EET analogs and characterized their vasodilator agonist
and antagonist activity in bovine coronary arteries. In this chapter, we first
review the mechanisms of EET-dependent relaxations in bovine coronary arteries
to familiarize the reader with the role of EETs in these arteries. The second
component is a synopsis of the functional characterization of the 14,15-EET
analogs and the resulting description of structural components required for
vascular dilator activity. Lastly, we discussed the characterization of three
14,15-EET analogs with specific EET-antagonist activity and compared this to the
activity of similar 11,12-EET analogs. These studies have revealed that specific
structural components of the 14,15-EET molecule are critical for dilator
activity and that alteration of these components influences agonist activity and
may confer antagonist properties. The epidermis expresses cyclooxygenases, lipoxygenases, and cytochromes P450,
which utilize arachidonic acid to generate a diverse array of lipid mediators
affecting epidermal cellular differentiation and functions. Recent studies show
that mouse epidermis expresses CYP2B19, a keratinocyte-specific epoxygenase that
generates 11,12- and 14,15-epoxyeicosatrienoic (EET) acids from arachidonate. We
studied CYP2B19-dependent metabolism in mouse epidermal microsomes,
reconstituted in the presence of [1-(14)C]arachidonic acid. The majority of the
(14)C products formed independently of NADPH, indicative of robust epidermal
cyclooxygenase and lipoxygenase activities. We studied two NADPH-dependent
products generated in a highly reproducible manner from arachidonate. One of
these (product I) coeluted with the CYP2B19 product 14,15-EET on a
reversed-phase high-performance liquid chromatography (HPLC) system; there was
no evidence for other regioisomeric EET products. Further analyses proved that
product I was not an epoxy fatty acid, based on different retention times on a
normal-phase HPLC system and failure of product I to undergo hydrolysis in
acidic solution. We analyzed purified epidermal (14)C products by liquid
chromatography negative electrospray ionization mass spectrometry. Structures of
the NADPH-dependent products were confirmed to be 12-oxo-5,8,14-eicosatrienoic
acid (I) and 12-hydroxy-5,8,14-eicosatrienoic acid (II). This was the first
evidence for a 12-hydroxy-5,8,14-eicosatrienoic acid biosynthetic pathway in
mouse epidermis. Epidermal microsomes also generated 12-hydroperoxy, 12-hydroxy,
and 12-oxo eicosatetraenoic acids from arachidonate, possible intermediates in
the 12-hydroxy-5,8,14-eicosatrienoic acid biosynthetic pathway. These results
predict that hydroxyeicosatrienoic acids are synthesized from arachidonate in
human epidermis. This would have important implications for human skin diseases
given the known pro- and anti-inflammatory activities of stereo- and
regioisomeric hydroxyeicosatrienoic acids. Epoxyeicosatrienoic acids (EETs) are synthesized from arachidonic acid by
cytochrome P450 epoxygenases in endothelial cells. It has previously been shown
that EETs activate K(+) channels, which are important for the hyperpolarization
and dilation of blood vessels. However, the effects of EETs on other ion
channels have been less well studied. We investigated the effects of EETs on
volume-activated Cl(-) channels (VACCs) in rat mesenteric arterial smooth muscle
cells. Whole-cell patch clamp recording demonstrated that hypotonic solution and
guanosine 5'-[gamma-thio]triphosphate (GTPgammaS) induced a
5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB)- and
4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS)-sensitive VACC current
in the primary cultured rat mesenteric arterial smooth muscle cells. The VACC
current was inhibited by EETs and the order of potency was
8,9-EET>5,6-EET>11,12-EET>14,15-EET. The inhibitory effects of EETs could be
reversed by 14,15 epoxyeicosa-5(Z)-enoic acid (14,15-EEZE, an EET analog),
Rp-cGMP and KT-5823 (protein kinase G inhibitors). Interestingly, the inhibitory
effects of EETs on VACCs were not influenced by Rp-cAMP (a protein kinase A
antagonist) but it could be abolished by NF-449 (a Gs protein inhibitor),
indicating the involvement of cAMP but not protein kinase A. In conclusion, our
results demonstrate that EETs inhibit VACCs in rat mesenteric arterial smooth
muscle cells through a cGMP-dependent pathway, which is probably due to the
cross-activation by cAMP. This mechanism may be involved in the regulation of
cell volume and membrane potential. Epoxyeicosatrienoic acids (EETs) are arachidonic acid metabolites produced by
cytochrome P450 epoxygenases which are highly expressed in hepatocytes. The
functions of EETs in hepatocytes are not well understood. In this study, we
investigated the effects of 14,15-EETs treatment on the insulin signal
transduction pathway in hepatocytes. We report that chronic treatment, not acute
treatment, with 30 μM 14,15-EETs prevents palmitate induced insulin resistance
and potentiates insulin action in cultured HepG2 hepatocytes. 14,15-EETs
increase Akt phosphorylation at S473, activating Akt, in an insulin dependent
manner in HepG2 cells. Under insulin resistant conditions induced by palmitate,
14,15-EETs restore the insulin response by increasing S473-phosphorylated Akt.
8,9-EETs and 11,12-EETs demonstrated similar effects to 14,15-EETs. Furthermore,
14,15-EETs potentiate insulin-suppression of gluconeogenesis in cultured H4IIE
hepatocytes. To elucidate the mechanism of EETs function, we analyzed the
insulin signaling factors upstream of Akt. Inhibition of phosphatidylinositol
3-kinase (PI3K) with LY294002 attenuated the 14,15-EETs-induced activating
phosphorylation of Akt. 14,15-EETs reduced palmitate-stimulated phosphorylation
of IRS-1 on S312 and phosphorylation of c-Jun N-terminal kinase (JNK) at
threonine 183 and tyrosine 185 residues. The regulation of insulin sensitivity
in cultured hepatocytes by chronic 14,15-EETs treatment appears to involve the
JNK-IRS-PI3K pathway. The requirement of chronic treatment with EETs suggests
that the effects of EETs on insulin response may be indirect. In addition to their role as xenobiotic metabolizing enzymes, cytochrome P450
(CYP) epoxygenases actively contribute to the metabolism of endogenous
substances such as arachidonic acid. Epoxyeicosatrienoic acids (EETs) are
epoxide derivative of arachidonic acid. CYP2C8/9 and CYP2J2 are the main
epoxygenases expressed in human tissues including endothelial cells which are
the chief sources of EET formation in human body. Once formed, EETs are
primarily metabolized to their less biologically active metabolites,
dihydroxyeicosatrienoic acids, by soluble epoxy hydrolase (sEH) enzyme. EETs
possess a wide range of established protective effects on human cardiovascular
system of which vasodilatory, angiogenic and anti-inflammatory actions have been
more extensively described. On the other hand, inflammation has shown to
decrease the expression and activity of CYP enzyme, including epoxygenases.
Given the fact that CYP epoxygenase-derive EETs exhibit potent cardiovascular
protective effects, including anti-inflammation, and that inflammation suppress
CYP activation and EET formation, it would make sense to speculate that under
inflammatory conditions there exists an
inflammation-epoxygenase-EET-inflammation vicious cycle in which the
inflammation-induced downregulation of CYP epoxygenases causes a decrease in the
EET production. Insufficient EET synthesis would, in turn, lead to an
ineffective EET-mediated anti-inflammatory effect, leading to an augmentation of
systemic and regional inflammatory responses and further downregulation of CYP
epoxygenase activity/EET production. This cycle, if any, might help to better
understanding of pathophysiology of chronic cardiovascular diseases and also
could be an emerging target for further pharmacological therapy of disorders in
which increased inflammatory responses are known to occur. The environmental toxin and carcinogen 2,3,7,8-tetrachlorodibenzo-p-dioxin
(TCDD, dioxin) binds and activates the transcription factor aryl hydrocarbon
receptor (AHR), inducing CYP1 family cytochrome P450 enzymes. CYP1A2 and its
avian ortholog CYP1A5 are highly active arachidonic acid epoxygenases.
Epoxygenases metabolize arachidonic acid to four regioisomeric
epoxyeicosatrienoic acids (EETs) and selected monohydroxyeicosatetraenoic acids
(HETEs). EETs can be further metabolized by epoxide hydrolases to
dihydroxyeicosatrienoic acids (DHETs). As P450-arachidonic acid metabolites
affect vasoregulation, responses to ischemia, inflammation, and metabolic
disorders, identification of their production in vivo is needed to understand
their contribution to biologic effects of TCDD and other AHR activators. Here we
report use of an acetonitrile-based extraction procedure that markedly increased
the yield of arachidonic acid products by lipidomic analysis over a standard
solid-phase extraction protocol. We show that TCDD increased all four EETs
(5,6-, 8,9-, 11,12-, and 14,15-), their corresponding DHETs, and 18- and 20-HETE
in liver in vivo and increased 5,6-EET, the four DHETs, and 18-HETE in heart, in
a chick embryo model. As the chick embryo heart lacks arachidonic
acid-metabolizing activity, the latter findings suggest that arachidonic acid
metabolites may travel from their site of production to a distal organ, i.e.,
heart. To determine if the TCDD-arachidonic acid-metabolite profile could be
altered pharmacologically, chick embryos were treated with TCDD and the soluble
epoxide hydrolase inhibitor 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA).
Cotreatment with AUDA increased hepatic EET-to-DHET ratios, indicating that the
in vivo profile of P450-arachidonic acid metabolites can be modified for
potential therapeutic intervention. Epoxyeicosatrienoic acids (EETs) are potent lipid mediators formed by cytochrome
P450 epoxygenases from arachidonic acid. They consist of four regioisomers of
cis-epoxyeicosatrienoic acids: 5,6-, 8,9-, 11,12- and 14,15-EET. Here we
investigated whether these triene epoxides are electrophilic enough to form
covalent adducts with DNA in vitro. Using the thin-layer chromatography (TLC)
(32)P-postlabelling method for adduct detection we studied the reaction of
individual deoxynucleoside 3'-monophosphates and calf thymus DNA with the four
racemic EETs. Under physiological conditions (pH 7.4) only ±11,12-EET11,12-EET
formed adducts with DNA in a dose dependent manner detectable by the
(32)P-postlabelling method. However, when pre-incubated at pH 4 all four racemic
EETs were capable to bind to DNA forming several adducts. Under these conditions
highest DNA adduct levels were found with ±11,12-EET followed by ±5,6-EET,
±8,9-EET, and ±14,15-EET, all of them two orders of magnitude higher (between 3
and 1 adducts per 10(5) normal nucleotides) than those obtained with ±11,12-EET
at pH 7.4. Similar DNA adduct patterns consisting of up to seven spots were
observed with all four racemic EETs the most abundant adducts being derived from
the reaction with deoxyguanosine and deoxyadenosine. In summary, when analysed
by the (32)P-postlabelling method all four racemic EETs formed multiple DNA
adducts after activation by acidic pH, only ±11,12-EET produced DNA adducts in
aqueous solution at neutral pH. Therefore, we conclude from our in vitro studies
that EETs might be endogenous genotoxic compounds. Epoxyeicosatrienoic acids (EETs) are formed from arachidonic acid by the action
of P450 epoxygenases (CYP2C and CYP2J). Effects of EETs are limited by
hydrolysis by soluble epoxide hydrolase to less active dihydroxyeicosatrienoic
acids. Studies in rodent models provide compelling evidence that
epoxyeicosatrienoic acids exert favorable effects on glucose homeostasis, either
by enhancing pancreatic islet cell function or by increasing insulin sensitivity
in peripheral tissues. Specifically, the tissue expression of soluble epoxide
hydrolase appears to be increased in rodent models of obesity and diabetes.
Pharmacological inhibition of epoxide hydrolase or deletion of the gene encoding
soluble epoxide hydrolase (Ephx2) preserves islet cells in rodent models of type
1 diabetes and enhances insulin sensitivity in models of type 2 diabetes, as
does administration of epoxyeicosatrienoic acids or their stable analogues. In
humans, circulating concentrations of epoxyeicosatrienoic acids correlate with
insulin sensitivity, and a loss-of-function genetic polymorphism in EPHX2 is
associated with insulin sensitivity. Epoxyeicosatrienoic acids (EETs) are the epoxidation products of arachidonic
acid catalyzed by cytochrome P450 (CYP) epoxygenases, which possess multiple
biological activities. In the present study, we aimed to explore the role and
effects of CYP epoxygenases/EETs in wound healing in ob/ob mice. Full-thickness
skin dorsal wounds were made on ob/ob mice and C57BL/6 control mice. The mRNA
and protein expression of CYP epoxygenases were determined in granulation
tissues of wounds. Effects of EETs on wound healing were evaluated. Inflammation
and angiogenesis in wounds were also observed. Compared with C57BL/6 mice, the
mRNA and protein expression of CYP2C65 and CYP2J6 in the granulation tissues in
ob/ob mice were significantly reduced. 11,12-EET treatment significantly
improved wound healing in ob/ob mice, whereas 14,15-EEZE, an EET antagonist,
showed the opposite effect. 11,12-EET treatment decreased neutrophil and
macrophage infiltration to the wound sites, resulting in reduced production of
inflammatory cytokines, decreased MMP-9 expression, and increased collagen
accumulation in the granulation tissues of ob/ob mice. In addition, 11,12-EET
increased angiogenesis in the granulation tissues of wounds in ob/ob mice. These
findings indicate that reduced expression of CYP epoxygenases may contribute to
impaired diabetic wound healing, and exogenous EETs may improve diabetic wound
healing by modulating inflammation and angiogenesis. Arachidonic acid is metabolized to epoxyeicosatrienoic acids (EETs) by
cytochrome (CYP) P450 epoxygenases, and to ω-terminal hydroxyeicosatetraenoic
acids (HETEs) by ω-hydroxylases. EETs and HETEs often have opposite biologic
effects; EETs are vasodilatory and protect against ischemia/reperfusion injury,
while ω-terminal HETEs are vasoconstrictive and cause vascular dysfunction.
Other oxylipins, such as epoxyoctadecaenoic acids (EpOMEs),
hydroxyoctadecadienoic acids (HODEs), and prostanoids also have varied vascular
effects. Post-ischemic vasodilation in the heart, known as coronary reactive
hyperemia (CRH), protects against potential damage to the heart muscle caused by
ischemia. The relationship among CRH response to ischemia, in mice with altered
levels of CYP2J epoxygenases has not yet been investigated. Therefore, we
evaluated the effect of endothelial overexpression of the human cytochrome P450
epoxygenase CYP2J2 in mice (Tie2-CYP2J2 Tr) on oxylipin profiles and CRH.
Additionally, we evaluated the effect of pharmacologic inhibition of
CYP-epoxygenases and inhibition of ω-hydroxylases on CRH. We hypothesized that
CRH would be enhanced in isolated mouse hearts with vascular endothelial
overexpression of human CYP2J2 through modulation of oxylipin profiles.
Similarly, we expected that inhibition of CYP-epoxygenases would reduce CRH,
whereas inhibition of ω-hydroxylases would enhance CRH. Compared to WT mice,
Tie2-CYP2J2 Tr mice had enhanced CRH, including repayment volume, repayment
duration, and repayment/debt ratio (P < 0.05). Similarly, inhibition of
ω-hydroxylases increased repayment volume and repayment duration, in Tie2-CYP2J2
Tr compared to WT mice (P < 0.05). Endothelial overexpression of CYP2J2
significantly changed oxylipin profiles, including increased EETs (P < 0.05),
increased EpOMEs (P < 0.05), and decreased 8-iso-PGF2α (P < 0.05). Inhibition of
CYP epoxygenases with MS-PPOH attenuated CRH (P < 0.05). Ischemia caused a
decrease in mid-chain HETEs (5-, 11-, 12-, 15-HETEs P < 0.05) and HODEs (P <
0.05). These data demonstrate that vascular endothelial overexpression of
CYP2J2, through changing the oxylipin profiles, enhances CRH. Inhibition of CYP
epoxygenases decreases CRH, whereas inhibition of ω-hydroxylases enhances CRH. OBJECTIVE: Arachidonic acid metabolism by cytochrome P450 (CYP) epoxygenases
leads to epoxyeicosatrienoic acids (EETs), which are eicosanoids with
vasodilator and anti-inflammatory properties. We aim to determine whether
genetic variability in these routes may contribute to cardiovascular (CV) risk
in renal transplant recipients.
METHODS: In a cohort of 355 patients, we determined the presence of two
polymorphisms, CYP2C8*3 and CYP2J2*7, known to affect eicosanoid levels.
Associations with CV mortality, CV event-free long-term survival and graft
survival were retrospectively investigated by logistic regression models.
RESULTS: CYP2J2*7 showed a statistical trend towards higher CV mortality
(p = .06) and lower cardiac or cerebral event-free long-term survival (p = .05),
whilst CYP2C8*3 displayed a significant inverse association with the risk of CV
event (hazard ratio [HR] = 0.34 [0.15-0.78], p = .01). The association of
CYP2J2*7 with CV mortality became significant when the analysis was restrained
to 316 patients without a history of CV events prior to transplantation
(HR = 15.72 [2.83-91.94], p = .005). In this subgroup of patients both single
nucleotide polymorphisms (SNPs) were significantly associated with event-free
survival. HR values were 5.44 (1.60-18.51), p = .007 and 0.26 (0.09-0.75),
p = .012 for CYP2J2*7 and CYP2C8*3, respectively.
CONCLUSIONS: Our results show, for the first time to our knowledge, that two
SNPs in CYP2C8 and CYP2J2, which synthesize EETs, may modify CV outcomes in
renal transplant recipients, a population that is already at a high risk of
suffering these events. |
What percentage of currently available drugs are metabolized by CYP3A4? | CYP3A4 metabolizes approximately 50% of the drugs available today on the market. | The use of medicinal plants concomitantly with conventional drugs can result in
herb-drug interactions that cause fluctuations in drug bioavailability and
consequent therapeutic failure and/or toxic effects. The CYP superfamily of
enzymes plays an important role in herb-drug interactions. Among CYP enzymes,
CYP3A4 and CYP2D6 are the most relevant since they metabolize about 50% and 30%
of the drugs on the market, respectively. Thus, the main goal of this study was
to evaluate the occurrence of in vitro interactions between medicinal plant
extracts and drug substrates of CYP3A4 and CYP2D6 enzymes. Standardized extracts
from nine medicinal plants (Bauhinia forficata, Cecropia glaziovii, Cimicifuga
racemosa, Cynara scolymus, Echinacea sp., Ginkgo biloba, Glycine max, Ilex
paraguariensis, and Matricaria recutita) were evaluated for their potential
interactions mediated by CYP3A4 and CYP2D6 enzymes. Among the extracts tested,
C. glaziovii (red embaúba) showed the most relevant inhibitory effects of CYP3A4
and CYP2D6 activity, while I. paraguariensis (yerba mate) inhibited CYP3A4
activity. Both extracts were chemically analyzed by UPLC-MS/MS, and these
inhibitory effects could lead to clinically potential and relevant interactions
with the drug substrates of these isoenzymes. |
What is caused by bi-allelic loss-of-function variants in IPO8? | Bi-allelic loss-of-function variants in IPO8 cause a syndromic form of thoracic aortic aneurysm (TAA) with clinical overlap with Loeys-Dietz and Shprintzen-Goldberg syndromes. | Author information:
(1)Center of Medical Genetics, University of Antwerp and Antwerp University
Hospital, Edegem 2650, Belgium.
(2)Center of Medical Genetics, University of Antwerp and Antwerp University
Hospital, Edegem 2650, Belgium; Department of Human Genetics, Radboud University
Nijmegen Medical Center, Nijmegen 6525 GA, the Netherlands.
(3)Laboratory of Physiopharmacology, University of Antwerp, Antwerp 2610,
Belgium.
(4)Center of Medical Genetics, University of Antwerp and Antwerp University
Hospital, Edegem 2650, Belgium; StatUa Center for Statistics, University of
Antwerp, Antwerp 2000, Belgium.
(5)Center of Medical Genetics, University of Antwerp and Antwerp University
Hospital, Edegem 2650, Belgium; Laboratory of Molecular, Cellular and Network
Excitability, Department of Biomedical Sciences, University of Antwerp, Antwerp
2610, Belgium.
(6)Laboratory of Cell Biology & Histology, Department of Veterinary Sciences,
University of Antwerp, Antwerp 2610, Belgium.
(7)Prince Sultan Cardiac Centre, Qassim 31982, Saudi Arabia.
(8)NIHR Oxford Biomedical Research Centre, Wellcome Centre for Human Genetics,
University of Oxford, Oxford OX3 7BN, UK.
(9)Bristol Genetics Laboratory, South West Genomic Laboratory Hub, Southmead
Hospital, Bristol BS10 5NB, UK.
(10)Department of Molecular and Human Genetics, Baylor College of Medicine,
Houston, TX 77030, USA; Baylor Genetics Laboratories, Houston, TX 77021, USA.
(11)Department of Pediatric Cardiology, Cliniques Universitaires Saint-Luc,
University of Louvain, Brussels 1200, Belgium.
(12)Birmingham Women's and Children's Hospital NHS Foundation Trust, Steelhouse
Lane, Birmingham B4 6NH, UK.
(13)Birmingham Women & Children's Hospital, Birmingham B4 6NH, UK.
(14)Musgrove Park Hospital, Somerset NHS Foundation Trust, Taunton TA1 5DA, UK.
(15)Department of Paediatric Neurology, University Hospitals Bristol NHS
Foundation Trust, Bristol BS2 8BJ, UK.
(16)Pediatric Department, Faculty of Medicine, Mashhad University of Medical
Sciences, Mashhad 009851, Iran.
(17)Department of Pediatric Neurology, School of Medicine, Mashhad University of
Medical Sciences, Mashhad 009851, Iran.
(18)Department of Molecular Genetics, Next Generation Genetic Polyclinic,
Mashhad University of Medical Sciences, Mashhad 009851, Iran.
(19)Department of Pediatric Neurology, Ghaem Hospital, Mashhad University of
Medical Sciences, Mashhad 009851, Iran.
(20)Cardiovascular Genetic Program, Department of Medical Genetics, King Faisal
Specialist Hospital and Research Centre, Riyadh 11564, Saudi Arabia.
(21)West Midlands Regional Genetics Service, Birmingham Women's and Children's
Hospital, Birmingham, B15 2TG, UK.
(22)Center for Human Genetics, Cliniques Universitaires Saint-Luc, University of
Louvain, Brussels 1200, Belgium.
(23)Centre de Génétique Humaine, Institut de Pathologie et de Génétique,
Gosselies (Charleroi) 6041, Belgium.
(24)The Heart Institute, Department of Pediatrics, Cincinnati Children's
Hospital Medical Center and University of Cincinnati College of Medicine,
Cincinnati, OH 45229, USA.
(25)Division of Human Genetics, Department of Pediatrics, Cincinnati Children's
Hospital Medical Center and University of Cincinnati College of Medicine,
Cincinnati, OH 45229, USA.
(26)GeneDx, Gaithersburg, MD 20877, USA.
(27)Department of Neuromuscular Disorders, UCL Queen Square Institute of
Neurology, London, WC1N 3BG, UK.
(28)Center of Medical Genetics, University of Antwerp and Antwerp University
Hospital, Edegem 2650, Belgium; Department of Human Genetics, Radboud University
Nijmegen Medical Center, Nijmegen 6525 GA, the Netherlands. Electronic address:
[email protected].
(29)Center of Medical Genetics, University of Antwerp and Antwerp University
Hospital, Edegem 2650, Belgium. Electronic address:
[email protected]. |
What is the mechanism of action of Evinacumab? | Evinacumab is a monoclonal antibody against angiopoietin-like protein 3 (ANGPTL3) that has been shown to reduce low-density lipoprotein cholesterol in patients with homozygous familial hypercholesterolemia. | BACKGROUND: Hypertriglyceridemia is associated with increased cardiovascular
risk and may be caused by impaired lipoprotein clearance. Angiopoietin-like
protein 3 (ANGPTL3) inhibits lipoprotein lipase activity, increasing
triglycerides and other lipids. Evinacumab, an ANGPTL3 inhibitor, reduced
triglycerides in healthy human volunteers and in homozygous familial
hypercholesterolemic individuals. Results from 2 Phase 1 studies in
hypertriglyceridemic subjects are reported here.
METHODS: Subjects with triglycerides >150 but ≤450 mg/dL and low-density
lipoprotein cholesterol ≥100 mg/dL (n=83 for single ascending dose study [SAD];
n=56 for multiple ascending dose study [MAD]) were randomized 3:1 to
evinacumab:placebo. SAD subjects received evinacumab subcutaneously at
75/150/250 mg, or intravenously at 5/10/20 mg/kg, monitored up to day 126. MAD
subjects received evinacumab subcutaneously at 150/300/450 mg once weekly,
300/450 mg every 2 weeks, or intravenously at 20 mg/kg once every 4 weeks up to
day 56 with 6 months of follow-up. The primary outcomes were incidence and
severity of treatment-emergent adverse events. Efficacy analyses included
changes in triglycerides and other lipids over time.
RESULTS: In the SAD, 32 (51.6%) versus 9 (42.9%) subjects on evinacumab versus
placebo reported treatment-emergent adverse events. In the MAD, 21 (67.7%)
versus 9 (75.0%) subjects on subcutaneously evinacumab versus placebo and 6
(85.7%) versus 1 (50.0%) on intravenously evinacumab versus placebo reported
treatment-emergent adverse events. No serious treatment-emergent adverse events
or events leading to death or treatment discontinuation were reported.
Elevations in alanine aminotransferase (7 [11.3%] SAD), aspartate
aminotransferase (4 [6.5%] SAD), and creatinine phosphokinase (2 [3.2%) SAD, 1
[14.3%] MAD) were observed with evinacumab (none in the placebo groups), which
were single elevations and were not dose-related. Dose-dependent reductions in
triglycerides were observed in both studies, with maximum reduction of 76.9% at
day 3 with 10 mg/kg intravenously (P<0.0001) in the SAD and of 83.1% at day 2
with 20 mg/kg intravenously once every 4 weeks (P=0.0003) in the MAD.
Significant reductions in other lipids were observed with most evinacumab doses
versus placebo.
CONCLUSION: Evinacumab was well-tolerated in 2 Phase 1 studies. Lipid changes in
hypertriglyceridemic subjects were similar to those observed with ANGPTL3
loss-of-function mutations. Because the latter is associated with reduced
cardiovascular risk, ANGPTL3 inhibition may improve clinical outcomes.
CLINICAL TRIAL REGISTRATION: https://www.clinicaltrials.gov. Unique identifiers:
NCT01749878 and NCT02107872. INTRODUCTION: The prevalence of hypertriglyceridemia (HTG) is increasing.
Elevated triglyceride (TG) levels are associated with an increased
cardiovascular disease (CVD) risk. Moreover, severe HTG results in an elevated
risk of pancreatitis, especially in severe HTG with an up to 350-fold increased
risk. Both problems emphasize the clinical need for effective TG lowering.
AREAS COVERED: The purpose of this review is to discuss the currently available
therapies and to elaborate the most promising novel therapeutics for TG
lowering.
EXPERT OPINION: Conventional lipid lowering strategies do not efficiently lower
plasma TG levels, leaving a residual CVD and pancreatitis risk. Both
apolipoprotein C-III (apoC-III) and angiopoietin-like 3 (ANGPTL3) are important
regulators in TG-rich lipoprotein (TRL) metabolism. Several novel agents
targeting these linchpins have ended phase II/III trials. Volanesorsen targeting
apoC-III has shown reductions in plasma TG levels up to 90%. Multiple ANGPLT3
inhibitors (evinacumab, IONIS-ANGPTL3-LRx, ARO-ANG3) effectuate TG reductions up
to 70% with concomitant potent reduction in all other apoB containing
lipoprotein fractions. We expect these therapeutics to become players in the
treatment for (especially) severe HTG in the near future. BACKGROUND: Homozygous familial hypercholesterolemia is characterized by
premature cardiovascular disease caused by markedly elevated levels of
low-density lipoprotein (LDL) cholesterol. This disorder is associated with
genetic variants that result in virtually absent (null-null) or impaired
(non-null) LDL-receptor activity. Loss-of-function variants in the gene encoding
angiopoietin-like 3 (ANGPTL3) are associated with hypolipidemia and protection
against atherosclerotic cardiovascular disease. Evinacumab, a monoclonal
antibody against ANGPTL3, has shown potential benefit in patients with
homozygous familial hypercholesterolemia.
METHODS: In this double-blind, placebo-controlled, phase 3 trial, we randomly
assigned in a 2:1 ratio 65 patients with homozygous familial
hypercholesterolemia who were receiving stable lipid-lowering therapy to receive
an intravenous infusion of evinacumab (at a dose of 15 mg per kilogram of body
weight) every 4 weeks or placebo. The primary outcome was the percent change
from baseline in the LDL cholesterol level at week 24.
RESULTS: The mean baseline LDL cholesterol level in the two groups was 255.1 mg
per deciliter, despite the receipt of maximum doses of background lipid-lowering
therapy. At week 24, patients in the evinacumab group had a relative reduction
from baseline in the LDL cholesterol level of 47.1%, as compared with an
increase of 1.9% in the placebo group, for a between-group least-squares mean
difference of -49.0 percentage points (95% confidence interval [CI], -65.0 to
-33.1; P<0.001); the between-group least-squares mean absolute difference in the
LDL cholesterol level was -132.1 mg per deciliter (95% CI, -175.3 to -88.9;
P<0.001). The LDL cholesterol level was lower in the evinacumab group than in
the placebo group in patients with null-null variants (-43.4% vs. +16.2%) and in
those with non-null variants (-49.1% vs. -3.8%). Adverse events were similar in
the two groups.
CONCLUSIONS: In patients with homozygous familial hypercholesterolemia receiving
maximum doses of lipid-lowering therapy, the reduction from baseline in the LDL
cholesterol level in the evinacumab group, as compared with the small increase
in the placebo group, resulted in a between-group difference of 49.0 percentage
points at 24 weeks. (Funded by Regeneron Pharmaceuticals; ELIPSE HoFH
ClinicalTrials.gov number, NCT03399786.). Publisher: La quilomicronemia familiar es una condición en que una mutación
genética altera la capacidad de metabolizar los triglicéridos que viajan en las
lipoproteínas, causando elevación extrema de triglicéridos plasmáticos y
complicaciones asociadas. La complicación más frecuente es la pancreatitis, que
puede llevar a falla multiorgánica o insuficiencia pancreática. La
quilomicronemia familiar también afecta la calidad de vida, las relaciones
sociales y el desarrollo profesional. El gen más frecuentemente afectado en la
quilomicronemia familiar es el de lipoproteína lipasa-1 (LPL), enzima que
hidroliza triglicéridos circulantes para su captación tisular. Mutaciones en
genes (como APOC2, APOAV, LMF-1, GPIHBP-1) que codifican para proteínas que
regulan la maduración, transporte o polimerización de lipoproteína lipasa-1,
también pueden estar involucradas. Sin embargo, en cerca del 30% de los
pacientes no se encuentra la variante causal. La quilomicronemia familiar debe
sospecharse en casos de hipertrigliceridemia extrema, resistente al tratamiento
convencional, o que se acompaña de xantomas eruptivos, lipemia retinalis o dolor
abdominal. La disponibilidad de escalas de riesgo y pruebas genéticas deben
promover la detección oportuna. La nutrición se basa en una dieta muy baja en
grasa con adecuada suplencia de vitaminas liposolubles y ácidos grasos
esenciales, además de evitar el consumo de alcohol. Si bien el tratamiento
farmacológico incluye fibratos y ácidos grasos omega 3, el enfoque actual
privilegia agentes biotecnológicos dirigidos a los defectos moleculares propios
de la enfermedad. Ello incluye un oligonucleótido antisentido dirigido contra
apoC-III (volanesorsen), un anticuerpo monoclonal contra la proteína similar a
angiopoietina tipo 3 (evinacumab), y otros compuestos en desarrollo. Introduction: Homozygous Familial Hypercholesterolemia (HoFH) is a very severe
genetic form of hypercholesterolemia. Lacking LDL receptors in the liver,
subjects with HoFH have raised plasma levels of LDL cholesterol, and up to 100
times higher risk of premature atherosclerotic cardiovascular disease than the
general population.Areas covered: This evaluation is of a phase 3 trial of
evinacumab; Evinacumab Lipid Studies in Patients with Homozygous Familial
Hypercholesterolemia (ELIPSE HoFH). Evinacumab is a human monoclonal antibody
inhibitor of angiopoietin-like protein 3 (ANGPTL3). In ELIPSE HoFH, evinacumab
reduced LDL cholesterol by 47.1 ± 4.6%, HDL cholesterol by 30.4%, and
triglycerides by 50.4 ± 7.7%.Expert opinion: Evinacumab is not the ideal
treatment for HoFH as it does not reduce LDL cholesterol levels to treatment
targets while increasing HDL cholesterol. Although the incidence of adverse
effects with evinacumab was low in ELIPSE HoFH, further studies are necessary to
clarify its effects on liver enzymes and clinical cardiovascular outcomes.
Evinacumab is a candidate to become the standard treatment for HoFH, as it may
be better tolerated and/or more efficacious than the presently available
specific treatment (lomitapide). However, the widespread use of evinacumab to
treat high triglycerides or LDL cholesterol is unlikely due to evinacumab
decreasing HDL cholesterol. Introduction: Familial hypercholesterolemia (FH) is characterized by lifelong
elevation of low-density lipoprotein cholesterol (LDL-C), early onset coronary
atherosclerosis, and premature death. FH is underdiagnosed and undertreated, but
requires aggressive LDL-C-lowering to prevent complications. Current treatment
strategies such as lifestyle modification and numerous LDL-C-lowering
medications are often insufficient to achieve lipid goals in FH.Areas covered:
Angiopoietin-like 3 protein (ANGPTL3) is intricately involved in lipid
metabolism. Loss-of-function mutations in ANGPTL3 are associated with
panhypolipidemia and reduced coronary atherosclerosis. Evinacumab, a fully human
monoclonal antibody, inhibits ANGPTL3 and reduces multiple lipoprotein fractions
~50%, including LDL-C. The use of evinacumab within the FH population is
described as well as its regulatory journey to an approved therapeutic.Expert
opinion: Evinacumab, with its capacity to lower multiple lipoprotein fractions,
particularly LDL-C, independently of LDLR function has potential to
revolutionize treatment for FH patients. Current FDA-approval is only for
homozygous FH (HoFH), arguably the most impactful indication, but use in other
lipid disorders is under investigation. The short-term tolerability of
evinacumab is very good, with infrequent, mild, and transient adverse events;
however, long-term safety data are needed. The high cost and requirement for
intravenous administration may limit adoption of evinacumab, but dramatic
LDL-C-lowering and need for new therapeutic options for HoFH will drive
interest. |
Which glands in the bee secretes royal jelly? | hypopharyngeal glands | The hypopharyngeal glands (HPGs) of worker honeybees undergo physiological
changes along with the age-dependent role change from nursing to foraging: nurse
bee HPGs secrete mainly major royal jelly proteins, whereas forager HPGs secrete
mainly α-glucosidase III, which converts the sucrose in the nectar into glucose
and fructose. We previously identified two other genes, Apis mellifera buffy
(Ambuffy) and Apis mellifera matrix metalloproteinase 1 (AmMMP1), with enriched
expression in nurse bee and forager HPGs, respectively. In the present study, to
clarify the molecular mechanisms that coordinate HPG physiology with worker
behavior, we first analyzed whether Ambuffy, AmMMP1, mrjp2 (a gene encoding one
of major royal jelly protein isoforms), and Hbg3 (a gene encoding α-glucosidase
III) expression, is associated with worker behavior in 'single-cohort colonies'
where workers of almost the same age perform different tasks. Expression of
these genes correlated with the worker's role, while controlling for age,
indicating their regulation associated with the worker's behavior. Associated
gene expression suggested the possible involvement of some hormonal factors in
its regulation. We therefore examined the relationship between ecdysone- and
juvenile hormone (JH)-signaling, and the expression profiles of these
'indicator' genes (nurse bee HPG-selective genes: mrjp2 and Ambuffy, and forager
HPG-selective genes: Hbg3 and AmMMP1). Expression of both ecdysone-regulated
genes (ecdysone receptor, mushroom body large type Kenyon cell specific
protein-1, and E74) and JH-regulated genes (Methoprene tolerant and Krüppel
homolog 1) was higher in the forager HPGs than in the nurse bee HPGs, suggesting
the possible roles of ecdysone- and JH-regulated genes in worker HPGs.
Furthermore, 20-hydroxyecdysone-treatment repressed both nurse bee- and
forager-selective gene expression, whereas methoprene-treatment enhanced the
expression of forager-selective genes and repressed nurse bee-selective genes in
the HPGs. Our findings suggest that both ecdysone- and JH-signaling
cooperatively regulate the physiological state of the HPGs in association with
the worker's behavior. The hypopharyngeal glands (HGs) of honey bee nurse workers secrete the major
protein fraction of jelly, a protein and lipid rich substance fed to developing
larvae, other worker bees, and queens. A hallmark of poorly nourished nurses is
their small HGs, which actively degrade due to hormone-induced autophagy. To
better connect nutritional stress with HG degradation, we looked to honey bees
and other insect systems, where nutrient stress is often accompanied by fat body
degradation. The fat body contains stored lipids that are likely a substrate for
ecdysteroid synthesis, so we tested whether starvation caused increased fat body
lipolysis. Ecdysteroid signaling and response pathways and IIS/TOR are tied to
nutrient-dependent autophagy in honey bees and other insects, and so we also
tested whether and where genes in these pathways were differentially regulated
in the head and fat body. Last, we injected nurse-aged bees with the honey bee
ecdysteroid makisterone A to determine whether this hormone influenced HG size
and autophagy. We find that starved nurse aged bees exhibited increased fat body
lipolysis and increased expression of ecdysteroid production and response genes
in the head. Genes in the IIS/TOR pathway were not impacted by starvation in
either the head or fat body. Additionally, bees injected with makisterone A had
smaller HGs and increased expression of autophagy genes. These data support the
hypothesis that nutritional stress induces fat body lipolysis, which may
liberate the sterols important for ecdysteroid production, and that increased
ecdysteroid levels induce autophagic HG degradation. The genome of the western honeybee (Apis mellifera) harbors nine transcribed
major royal jelly protein genes (mrjp1-9) which originate from a single-copy
precursor via gene duplication. The first MRJP was identified in royal jelly, a
secretion of the bees' hypopharyngeal glands that is used by young worker bees,
called nurses, to feed developing larvae. Thus, MRJPs are frequently assumed to
mainly have functions for developing bee larvae and to be expressed in the food
glands of nurse bees. In-depth knowledge on caste- and age-specific role and
abundance of MRJPs is missing. We here show, using combined quantitative
real-time PCR with quantitative mass spectrometry, that expression and protein
amount of mrjp1-5 and mrjp7 show an age-dependent pattern in worker's
hypopharyngeal glands as well as in brains, albeit lower relative abundance in
brains than in glands. Expression increases after hatching until the nurse bee
period and is followed by a decrease in older workers that forage for plant
products. Mrjp6 expression deviates considerably from the expression profiles of
the other mrjps, does not significantly vary in the brain, and shows its highest
expression in the hypopharyngeal glands during the forager period. Furthermore,
it is the only mrjp of which transcript abundance does not correlate with
protein amount. Mrjp8 and mrjp9 show, compared to the other mrjps, a very low
expression in both tissues. Albeit mrjp8 mRNA was detected via qPCR, the protein
was not quantified in any of the tissues. Due to the occurrence of MRJP8 and
MRJP9 in other body parts of the bees, for example, the venom gland, they might
not have a hypopharyngeal gland- or brain-specific function but rather functions
in other tissues. Thus, mrjp1-7 but not mrjp8 and mrjp9 might be involved in the
regulation of phenotypic plasticity and age polyethism in worker honeybees. |
List the common retinal diseases associated with circRNAs. | Circular RNAs (circRNAs) in whole blood could be served as novel non-invasive biomarkers for retinal degeneration, diabetic retinopathy, proliferative diabetic retinopathy (PDR) and Retinopathy of prematurity (ROP) | PURPOSE: To reveal the expression profile and clinical significance of circular
RNAs (circRNAs) in diabetic retinopathy (DR).
METHODS: Circular RNA microarrays were performed to identify DR-related
circRNAs. Gene ontology (GO) enrichment and KEGG analysis was performed to
determine the biologic modules and signaling pathway. TargetScan and miRana
program was used to predict circRNA/miRNA interaction. Quantitative PCR assays
were performed to detect circRNA expression pattern in clinical samples. Ki67
staining, Transwell, tube formation, and spheroid sprouting assays were
performed to investigate the role and mechanism of circRNA in endothelial
angiogenic function.
RESULTS: A total of 529 circRNAs were aberrantly expressed in diabetic retinas.
The host genes of differentially expressed circRNAs were targeted to ATP binding
(biologic process); extracellular exosome (cellular component); and
intracellular signal transduction (molecular function). Circ_0005015 was
verified to be upregulated in the plasma, vitreous sample, and fibrovascular
membranes of DR patients. Circ_0005015 facilitated retinal endothelial
angiogenic function via regulating endothelial cell proliferation, migration,
and tube formation. Circ_0005015 acted as miR-519d-3p sponge to inhibit
miR-519d-3p activity, leading to increased MMP-2, XIAP, and STAT3 expression.
CONCLUSIONS: circRNAs are involved in DR pathogenesis, and thus serve as
potential biomarkers of DR diagnosis. BACKGROUND: Diabetic retinopathy, a vascular complication of diabetes mellitus,
is the leading cause of visual impairment and blindness. circRNAs act as
competing endogenous RNA, sponging target miRNA and thus influencing mRNA
expression in vascular diseases. We investigated whether and how circDNMT3B is
involved in retinal vascular dysfunction under diabetic conditions.
METHODS: qRT-PCR was performed to detect expression of circDNMT3B, miR-20b-5p,
and BAMBI in retinal microvascular endothelial cells under diabetic conditions.
Western blot, Cell Counting Kit-8, Transwell, Matrigel tube formation, and
retinal trypsin digestion assays were conducted to explore the roles of
circDNMT3B/miR-20b-5p/BAMBI in retinal vascular dysfunction. Bioinformatics
analysis and luciferase reporter, siRNA, and overexpression assays were used to
reveal the mechanisms of the circDNMT3B/miR-20b-5p/BAMBI interaction.
Electroretinograms were used to evaluate visual function.
FINDINGS: Upregulation of miR-20b-5p under diabetic conditions promoted
proliferation, migration, and tube formation of human retinal microvascular
endothelial cells (HRMECs), which was mediated by downregulated BAMBI. Under
diabetic conditions, circDNMT3B, which acts as a sponge of miR-20b-5p, is
downregulated. circDNMT3B overexpression reduced retinal acellular capillary
number and alleviated visual damage in diabetic rats. Changes in expression of
circDNMT3B and miR-20b-5p were confirmed in the proliferative fibrovascular
membranes of patients with diabetic retinopathy.
INTERPRETATION: Downregulation of circDNMT3B contributes to vascular dysfunction
in diabetic retinas through regulating miR-20b-5p and BAMBI, providing a
potential treatment strategy for diabetic retinopathy.
FUNDING: National Natural Science Foundation of China, National Key Basic
Research Program of China, Shanghai Municipal Science and Technology Major
Project, and ZJLab. Non-coding RNAs (ncRNAs) are key players in variety of biogenesis and biological
functions. Their aberrant expression has been implicated in disease progression.
NcRNAs can be divided into short ncRNAs whose subtypes are mainly microRNA
(miRNA), long non-coding RNA (lncRNA) and circular RNA (circRNA). They are
involved in cellular processes, including gene regulation, development and
disease. The retina is a remarkably sophisticated instrument with interconnected
cell types and is the primary target of many genetic diseases. In addition, in
terms of retinal dyshomeostasis and inflammation, ncRNAs seems to play critical
roles in many retinal diseases. Here, we provide an overview of ncRNAs in
developing retina. We also review how does these ncRNAs function in various
retinal diseases including animal and human models. These data indicate that
ncRNAs regulate cellular processes including cell proliferation,
differentiation, apoptosis and contribute to initiation and progression of
retinal diseases. PURPOSE: This study aimed to determine whether circular RNAs (circRNAs) in whole
blood could be served as novel non-invasive biomarkers for proliferative
diabetic retinopathy (PDR).
METHODS: This retrospective cross-sectional study comprised 34 healthy
participants, 34 PDR patients and 34 non-proliferative DR (NPDR) patients.
High-throughput whole transcriptome sequencing was performed to explore the
expression profile of circRNAs in the whole blood, and the candidate circRNAs
were validated by quantitative real-time polymerase chain reaction (qRT-PCR).
Receiver operating characteristic (ROC) analysis evaluated the ability of these
candidate circRNAs in discriminating PDR patients from NPDR patients and healthy
subjects. Finally, the networks of circRNA-miRNA-mRNA based on the candidate
circRNAs were constructed.
RESULTS: Using sequencing and qRT-PCR, hsa_circ_0001953 was found to be elevated
in PDR patients in contrast with the other two groups. Statistical analysis
showed that the expression levels of hsa_circ_0001953 in PDR patients were
positively related to the duration of diabetes and HbAc1. Receiver operating
characteristic (ROC) curve analysis revealed that hsa_circ_0001953 was
associated with a high diagnostic accuracy in discriminating PDR patients from
NPDR patients and healthy controls, resulting in an area under the curve (AUC)
of 0.87 and 0.92, respectively. The circRNA-miRNA-target gene networks for
hsa_circ_0001953 showed that hsa_circ_0001953 could interact with dozens of
miRNAs and some targeted mRNAs have been potentially involved in the
pathogenesis of diabetes.
CONCLUSION: The present findings indicate that hsa_circ_0001953 in the whole
blood may serve as a novel diagnostic biomarker and potential therapeutic target
for PDR. Background: Increasing attention has been attracted by the role of circular RNAs
(circRNAs) in ocular diseases. Previous study has revealed that circ_0005941
(also known as circFTO, an alpha-ketoglutarate-dependent dioxygenase) was
upregulated in the vitreous humor of diabetic retinopathy (DR), while its
underlying mechanism in DR remains unknown. Methods: Retinal vascular
endothelial cells (RVECs) treated with high glucose (HG) were used to establish
the DR cell model. The in vivo assays were conducted using
streptozotocin-induced diabetic mice. The circular structure and stability of
circFTO were identified by Sanger sequencing and RNase R treatment. RT-qPCR
analysis was used to detect the RNA expression. The levels of the mRNA-encoded
protein thioredoxin-interacting protein (TXNIP) or angiogenesis-associated
proteins (VEGFA, PDGF, and ANG2) and blood-retinal barrier (BRB)-related
proteins (ZO-1, Occludin, and Claudin-5) were measured by Western blot. The
viability of RVECs was measured using CCK-8 assays. The angiogenesis of RVECs
was assessed using tube formation assays in vitro. Endothelial permeability
assays were conducted to examine the function of the BRB. The binding between
genes was explored using RNA pulldown and luciferase reporter assays. Results:
CircFTO was upregulated in HG-treated RVECs. CircFTO deficiency reversed the
HG-induced increase in the viability and angiogenesis of RVECs and alleviated
HG-mediated impairment of the BRB. MiR-128-3p bound with circFTO and was
downregulated in HG-treated RVECs. TXNIP was a downstream target gene of
miR-128-3p. TXNIP was highly expressed in the DR cell model. Rescue assays
revealed that circFTO promoted angiogenesis and impaired the blood-retinal
barrier by upregulating TXNIP. In the DR mouse model, circFTO silencing
inhibited angiogenesis and promoted BRB recovery in vivo. Conclusion: CircFTO
promotes angiogenesis and impairs the blood-retinal barrier in vitro and in vivo
by binding with miR-128-3p to upregulate TXNIP in DR. Circular RNAs (circRNAs) refer to a newly recognized family of non-coding RNA
with single-stranded RNAs. Despite emerging evidence indicating that circRNAs
are abundantly expressed in various tissues, especially in the brain and retina,
the role of circRNAs in retinal function and diseases is still largely unknown.
Circular Rims2 (circRims2) is highly expressed and conserved in both the human
and mouse brains. However, little is known about the expression and function of
circRims2 in the retina. In the current study, the high-throughput RNA-seq
analysis reveals a high expression of circRims2 in the retina. In addition, it
is found that circRims2 is mainly located in plexiform layers that contain
synapses between retinal neurons. Knocking down circRims2 with short hairpin RNA
through subretinal adeno-associated viral (AAV) delivery in the mice leads to
the decrease of the thickness of the outer and inner segment (OS/IS) layers and
outer nuclear layer (ONL), and cessation of scotopic and photopic
electroretinogram responses. Furthermore, the current study finds that circRims2
deficiency evokes retinal inflammation and activates the tumor necrosis factor
(TNF) signaling pathway. Therefore, circRims2 may play an important role in the
maintece of retinal structure and function, and circRims2 deficiency may lead
to pathogenic changes in the retina. |
How do CYP1A2 polymorphisms affect the habitual coffee consumption effect on apetite? | The CYP1A2 polymorphism -163C > A (rs762551) polymorphism renders carriers: rapid (AA), intermediate (AC), or slow (CC) caffeine metabolizers.
High coffee consumption was more prevalent in rapid compared to slow metabolizers (P = 0.008 after adjustment for age, sex, and BMI) and was associated with lower appetite perception and lower BMI only in rapid metabolizers (P for interaction of rs762551 genotype*coffee consumption = 0.002 and 0.048, respectively). | |
What is the role of SDE2? | SDE2 is a previously uncharacterized essential gene required for ribosome biogenesis and the regulation of alternative splicing. | RNA provides the framework for the assembly of some of the most intricate
macromolecular complexes within the cell, including the spliceosome and the
mature ribosome. The assembly of these complexes relies on the coordinated
association of RNA with hundreds of trans-acting protein factors. While some of
these trans-acting factors are RNA-binding proteins (RBPs), others are adaptor
proteins, and others still, function as both. Defects in the assembly of these
complexes results in a number of human pathologies including neurodegeneration
and cancer. Here, we demonstrate that Silencing Defective 2 (SDE2) is both an
RNA binding protein and also a trans-acting adaptor protein that functions to
regulate RNA splicing and ribosome biogenesis. SDE2 depletion leads to
widespread changes in alternative splicing, defects in ribosome biogenesis and
ultimately complete loss of cell viability. Our data highlight SDE2 as a
previously uncharacterized essential gene required for the assembly and
maturation of the complexes that carry out two of the most fundamental processes
in mammalian cells. |
Which drugs are included in the CABENUVA pill? | Cabenuva contains cabotegravir and rilpivirine. It is used for treatment of HIV. | In spite of introduction of combination antiretroviral therapy (cART) against
human immunodeficiency virus (HIV) infection; inaccessibility and poor adherence
to oral cART costs 10 in 100,000 death worldwide. Failure in adherence leads to
viral rebound, emergence of drug resistance and anticipated HIV infection in
high risk individuals. Various Long-acting antiretroviral (LA ARV)
oformulations including o-prodrug, solid drug oparticles (SDN),
ocrystals, aspherical oparticles, polymeric and lipidic oparticles have
shown plasma/tissue drug concentration in the therapeutic range for several
weeks during pre-clinical evaluation. LA ARV oformulations therefore have
replaced cART as better alternative for the treatment of HIV infection.
Cabenuva™ is recently approved by Health Canada containing LA cabotegravir+LA
rilpivirine ocrystals (ViiV healthcare) for once monthly administration by
intramuscular route. The LA oformulation due to its osize insist on better
stability, delivery to lymphatic, slow release into systemic circulation via
lymphatic-circulatory system conjoint and secondary drug depot within infiltered
immune cells at site of administration and systemic circulation in contrast to
conventional drugs. However, the pharmacokinetic, biodistribution and efficacy
of LA oformulations hinge onto physicochemical properties of the drugs and
route of administration. Therefore, current review emphasizes on these
contradistinctive factors that affects the reproducibility, safety, efficacy and
toxicity of LA anti-HIV oformulations. Moreover, it expatiates on application
of profuse oformulations for long-acting effect with promising preclinical
discoveries and two clinical leads. To add on, utilization of physiology-based
and mechanism-based pharmacokinetic modelling and in vivo animal models which
could lead to enhanced safety and efficacy of LA ARV oformulations in humans
have been included. Current combination antiretroviral therapy (cART) for human immunodeficiency
virus (HIV) is limited by the frequent dosing and unfavorable adherence, and the
rapid appearance of resistant mutants. Thus, there is a continuous need to
improve and optimize the present therapies. The clinical phase III trials of
FLAIR and ATLAS, showed two-drug injectable cabotegravir (CAB) and rilpivirine
(RPV) formulation is potent, safe, and tolerable in HIV-infected patients. The
recent approval of cabenuva (CAB+RPV) by Health Canada is a milestone in the
development of long-term therapies for HIV infection. Broadly neutralizing
antibodies (bNAbs) with excellent breath and efficiency against HIV have been
investigated as LA antiviral weapons. Several modern modalities capable of
sustained drug release for long-term treatment and prevention of HIV infection
are also in development, such as implants, vaginal rings, and otherapies. Cabenuva-an injectable formulation of cabotegravir and rilpivirine and the first
injectable complete therapy for adults with HIV-1-is now approved.It is
administered once a month as two intramuscular injections following a month of
treatment with the oral forms of these drugs. The approval of the novel long-acting HIV injection; Cabenuva®- Cabotegravir and
Rilpivirine injectable formulation) and the recent call by the World Health
Organization for promoting community-based ART management, underscore the
remarkable progress towards meeting the Joint United Nations Programme on
HIV/AIDS (UNAIDS) 95-95-95 targets by 2030. As the availability of
antiretroviral therapy (ART) for the treatment of HIV/AIDS has increased in
resource-limited settings, there has been a move to develop and implement
alternative treatment delivery models such as Differentiated Service Delivery
(DSD) in high prevalence countries to meet the global targets for HIV treatment
while maintaining the quality of care. However, there is limited data on the
involvement of community pharmacies in the delivery of ART within the community.
Although, in western countries, several studies have documented the different
roles community pharmacists can play in the management of HIV/AIDS. Community
pharmacists are the most accessible and first points of health care for most
clients. They are trusted, highly trained health care professionals. They should
be incorporated and allowed to administer the Cabenuva® injection if the battle
against the HIV pandemic is to be totally won. In this paper, we, therefore, aim
to explore how the community pharmacist can be positioned in HIV service
delivery regarding the administration of the Novel long-acting Cabenuva®
injection formulation. It is therefore recommended that the Nigerian government
embrace community pharmacy-led drug administration initiatives and embark on
accredited training programmes for the profession in line with drug
administration services. The government should also put in place necessary
funding mechanisms for community pharmacists for the extra workload placed on
them in administering injection drug formulation in their respective pharmacies. |
What is Shone's complex? | Shone's syndrome is a rare congenital heart disease that includes 4 cardiovascular anomalies: supravalvular mitral ring, parachute mitral valve, subaortic stenosis, and coarctation of the aorta. | OBJECTIVE: Shone's syndrome is a complex consisting of mitral valve stenosis in
addition to left ventricle outflow obstruction. There are a few studies
evaluating the long-term outcomes in this population. We sought to determine the
long-term outcomes in our paediatric population with Shone's syndrome and the
factors associated with left heart growth.
METHODS: All patients diagnosed with Shone's syndrome with biventricular
circulation treated between 1978 and 2010 were reviewed. Baseline
echocardiograms and data from catheterisations were also reviewed. Number of
interventions (surgical+transcatheter), incidence of mitral valve replacement,
and incidence of heart transplantation were tracked. Survival of the population
and left heart structural growth were also reviewed.
RESULTS: A total of 121 patients with Shone's syndrome presented at a median age
of 28 days (0-17.3 years) and were followed-up for 7.2 years (0.01-35.5 years).
These patients underwent 258 interventions during the study period, and the
presence of coarctation was associated with repeat left heart interventions. The
10-year, transplant-free survival was 86%. Presence of pulmonary hypertension
was associated with mortality. Left heart structural growth was seen for mitral
and aortic valve annuli and left ventricular end-diastolic dimension over time.
CONCLUSIONS: Shone's syndrome patients undergo a number of left heart
interventions. Coarctation of the aorta is associated with an increased
likelihood for repeat interventions. Survival appears to be more favourable than
expected. Significant left heart growth will occur in the population. Pulmonary
hypertension is associated with an increased risk of mortality. Shone's complex is a rare congenital cardiac malformation characterized by
serial obstructive lesions of the left heart at multiple levels. Presently
described is an unusual case of an adult male patient who presented with
palpitations and worsening dyspnea. An echocardiographic evaluation revealed
Shone's complex associated with left ventricular non-compaction cardiomyopathy
(NCC). To our knowledge, an association between NCC and Shone's complex has not
been previously described. BACKGROUND: Shone's complex is a rare lesion affecting the mitral valve (MV) and
left ventricular outflow tract (LVOT). The objective of this study is to report
the outcomes after Shone's complex repair, the growth of mitral and aortic valve
and LVOT, and long-term survival.
METHODS: This retrospective study included all patients diagnosed with Shone's
complex, who underwent biventricular repair. Data including patients'
characteristics, type of the MV lesion and the associated lesions were
collected. Patients were followed up regularly with echocardiography, and the
changes in mitral and aortic valve z-score and LVOT z-score were recorded.
RESULTS: Thirty-seven patients were included in the study, the median age was
3.4 months, and 11 patients (30.6%) had pulmonary hypertension. The main
procedure performed during the first surgical intervention was coarctation
repair in 26 patients (70%). Twelve patients had MV repair, and five had MV
replacement. Operative mortality occurred in 1 patient (2.7%), median follow up
was 52 (25-75th percentile: 22-84) months. Survival at 1, 5, and 10 years was
94.4%, 90%, and 76.9%, respectively. Reoperation was required in 13 patients,
mainly for LVOT repair (n = 8). Reoperation was significantly associated with
associated aortic valve lesion (p = .044). The growth of the MV z-score was 0.35
per year; p < .001, aortic valve z-score 0.086 per year; p = 0.422, and the LVOT
z-score was 0.53 per year; p = .01.
CONCLUSION: Biventricular repair of Shone's complex has good outcomes.
Reoperation is frequently encountered, especially with low aortic valve z-score.
The MV and LVOT have significant growth following Shone's complex repair. Shone's syndrome is a rare congenital heart disease that includes 4
cardiovascular anomalies: supravalvular mitral ring, parachute mitral valve,
subaortic stenosis, and coarctation of the aorta. Early diagnosis and treatment
result in better outcomes. Echocardiography plays an important role in the
diagnosis and is the optimal examination for detecting this disease. Pressure
gradients are often unreliable and inaccurate; thus, careful anatomical
observation of the left ventricular inflow and outflow tracts, particularly the
mitral valve, is vital for accurate diagnosis and planning appropriate
management. Herein, we describe 9 cases of Shone's syndrome, diagnosed with
echocardiography and treated surgically. |
What methods are used to diagnose bowel endometriosis? | Double-contrast barium enema (DCBE), transrectal endoscopic ultrasonography (REU), multidetector computerized tomography enema (MDCT-e), and computed tomography colonoscopy (CTC) have been successfully used for the diagnosis of bowel endometriosis. | OBJECTIVES: To evaluate a clinical examination during menstruation and plasma
CA-125 concentrations to diagnose deep endometriosis.
DESIGN: Prospective study in 61 women scheduled for a laparoscopy, a
retrospective study in 140 women with deep endometriosis, and a clinical
validation study in 16 women with painful pelvic nodularities during
menstruation.
SETTING: University Hospital Gasthuisberg, a tertiary referral center.
RESULTS: In the retrospective study, deep endometriosis was detected by routine
clinical examination in only 36% of women. Lesions infiltrating deeper than 15
mm were detected in 50%. In the prospective study pelvic nodularities were
detected by routine clinical examination in 4 women but were detected in 22 by
clinical examination during menstruation. The latter was highly reliable to
diagnose deep endometriosis, cystic ovarian endometriosis, and cul-de-sac
obliteration. CA-125 concentrations were higher during menstruation and
correlated with deep endometriosis and with deep and cystic ovarian
endometriosis. Nodularities at clinical examination or follicular phase CA-125
concentrations > 35 U/mL are useful to decide that a bowel preparation should be
given, achieving a sensitivity of 87% and a specificity of 83%. In the clinical
validation study, deep endometriosis was found in 14 of 16 women.
CONCLUSION: Clinical examination during menstruation can diagnose reliably deep
endometriosis, cystic ovarian endometriosis, or cul-de-sac adhesions. This test,
preferentially combined with a follicular phase CA-125 assay, should be used to
decide whether a preparation for bowel surgery should be given. Pelvic endometriosis in 3-37% of cases involves the intestinal tract, mainly
sigmoid colon and rectum. In clinical practice endometriosis of the intestinal
tract is rarely diagnosed and usually after long-lasting symptoms. During 3
years we treated only 2 women with this disease and therefore we want to report
this seldom disorder. One woman had been diagnosed as having had rectal
endometriosis before she was admitted to the hospital and the other one was
admitted because of complications after laparoscopic treatment of pelvic
endometriosis. In spite of typical signs of intestinal tract endometriosis, the
proper diagnosis was made after several years of symptoms in one woman and in
the second female histopathology of removed sigmoid colon because of its lesion
finally revealed endometriosis. Laparoscopy seems to be the best diagnostic
method of intestinal endometriosis and its treatment is to remove the involved
part of the bowel together with endometriotic foci and surrounding tissues.
Cyclical intestinal endometriosis symptoms correlating with menstrual cycle
should always draw our attention to this rare disorder. Bowel endometriosis opens a new frontier for the gynecologist, as it forces the
understanding of a new anatomy, a new physiology, and a new pathology. Although
some women with bowel endometriosis may be asymptomatic, the majority of them
develop a variety of gastrointestinal complains. No clear guideline exists for
the evaluation of patients with suspected bowel endometriosis. Given the fact
that, besides rectal nodules, bowel endometriosis can not be diagnosed by
physical examination, imaging techniques should be used. Several techniques have
been proposed for the diagnosis of bowel endometriosis including double-contrast
barium enema, transvaginal ultrasonography, rectal endoscopic ultrasonography,
magnetic resoce imaging, and multislice computed tomography enteroclysis.
Medical management of bowel endometriosis is currently speculative; expectant
management should be carefully balanced with the severity of symptoms and the
feasibility of prolonged follow-up. Several studies demonstrated an improvement
in quality of life after extensive surgical excision of the disease. Bowel
endometriotic nodules can be removed by various techniques: mucosal skinning,
nodulectomy, full thickness disc resection, and segmental resection. Although
the indications for colorectal resection are controversial, recent data suggest
that aggressive surgery improves symptoms and quality of life.
TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians.
LEARNING OBJECTIVES: After completion of this article, the reader should be able
to describe the varied appearance of bowel endometriosis, recall that it is
difficult to diagnose preoperatively, and explain that surgical treatment offers
the best treatment in symptomatic patients through a variety of surgical
techniques which is best accomplished with a team approach. BACKGROUND: Rectovaginal endometriosis is a severe form of pelvic endometriosis
in which pharmacological treatment is relatively ineffective (Vercellini et al.,
Fertil Steril. 2005;84:1375-87). Laparoscopic surgical treatment is effective,
but has the potential risks of bowel perforation and colostomy formation (Darai
et al., Am J Obstet Gynecol. 2005;192:394-400). Transrectal ultrasound scanning
can be applied as a preoperative tool to predict the presence of rectovaginal
endometriosis and bowel wall involvement (Abrao et al., J Am Assoc Gynecol
Laparosc. 2004;11:50-4).
METHODS: Thirty-two women underwent transrectal ultrasound followed by
therapeutic laparoscopy. Likelihood ratios and post-test prevalences were
calculated with Fagan's normogram. This was then extrapolated with the aid of a
mathematical model to a low-risk population.
RESULTS: A positive likelihood ratio was found to be 10.89 (95% confidence ratio
(CI): 1.62-73.15) and a negative likelihood ratio was found to be 0.24 (95% CI:
0.1-0.57). The pre-test prevalence of rectovaginal endometriosis was 56%. The
positive post-test prevalence probability was 93%, and the negative post-test
prevalence probability was 23%.
CONCLUSION: Preoperative transrectal ultrasound scanning for rectovaginal
endometriosis is an extremely accurate predictive test, and strongly predicts
the need for extensive laparoscopic dissection and potential bowel resection. STUDY OBJECTIVE: To evaluate the sensitivity, specificity, negative predictive
value, positive predictive value, association, and agreement of double-contrast
barium enema (DCBE) and transrectal endoscopic ultrasonography (Tr EUS) in the
diagnosis of rectosigmoid colon endometriosis.
DESIGN: Prospective nonrandomized (Canadian Task Force classification II-2).
SETTING: University hospital.
PATIENTS: We evaluated 37 patients with clinically suspected deeply infiltrating
endometriosis (DIE) from January 2004 through January 2005.
INTERVENTIONS: Clinical examination, DCBE, Tr EUS, and laparoscopy for
histologic confirmation.
MEASUREMENTS AND MAIN RESULTS: Deeply infiltrating endometriosis was confirmed
by laparoscopic visualization and by histopathologic examination in all
patients. Intestinal endometriosis was observed in 27 patients (72.9%). DCBE
showed abnormalities suggestive of bowel endometriosis in 24 patients (64.9%)
and Tr EUS in 28 patients (75.7%). Considering the DCBE findings we observed
among the 24 abnormal examination results, 16 (42.3%) had spiculation, 16
(42.3%) had circumferential narrowing of the bowel, and 4 (10.8%) had the mass
effect sign. For DCBE the sensitivity was 88%, the specificity was 54%, the
negative predictive value (NPV) was 70%, and the positive predictive value (PPV)
was 78%. For Tr EUS the sensitivity, specificity, NPV, and PPV were 96%, 100%,
90%, and 100%. A significant association of the DCBE and the Tr EUS in the
diagnosis of intestinal DIE (p = .017) and a moderate agreement of the methods
(kappa = 0.44) was also observed.
CONCLUSION: Our data, although limited by sample size, confirmed that DCBE has a
good sensitivity and a low specificity in the diagnosis of intestinal DIE. The
Tr EUS proved to have a higher sensitivity and specificity with elevated NPV and
PPV. A significant association of the DCBE and the Tr EUS in the diagnosis of
intestinal DIE and a moderate agreement of the methods was also observed. PURPOSE: To evaluate magnetic resoce (MR) imaging morphologic- and signal
intensity abnormalities of deep infiltrating endometriosis (DIE) of the bowel
wall and to assess its value in predicting depth and extent of bowel wall
infiltration.
MATERIALS AND METHODS: This single-center study was performed in a tertiary
referral center for endometriosis. All patients (n = 28) who underwent segmental
bowel resection (2004-2010) were retrospectively studied. MR images were
analyzed by two experienced readers independently (number of lesions, location,
size, signal intensity, and depth of bowel wall infiltration) and this was
correlated with histopathology.
RESULTS: The sensitivity, specificity, positive and negative predictive values,
and accuracy for diagnosis of endometriosis infiltrating the muscular layer of
the bowel were 100%, 75%, 96%, 100%, and 96%, respectively. The inter-rater
agreement was 0.84. "Fan shaped" configurations with hypointensity on T2- and
T1-weighted imaging were characteristic for thickening of indigenous smooth
muscle and smooth muscle hyperplasia at histopathology, as a consequence of
infiltration by endometriosis. Thickening of the (sub)mucosa corresponded to
edema with or without infiltration of endometriosis.
CONCLUSION: MR imaging at 1.5 Tesla is useful to predict muscular infiltration
of the bowel in endometriosis, whereas it is of limited value in diagnosis of
(sub)mucosal infiltration. STUDY OBJECTIVE: To evaluate the diagnostic contribution of the computed
tomography (CT) enema and magnetic resoce imaging (MRI) for multifocal
(multiple lesions affecting the same segment) and multicentric (multiple lesions
affecting several digestive segments) bowel endometriosis.
DESIGN: Prospective cohort study (Canadian Task Force classification II-2).
PATIENTS: Eighty-five patients.
SETTING: Tenon University Hospital, Paris, France.
INTERVENTION: All patients received a preoperative CT enema and underwent MRI
interpreted by 2 radiologists.
MEASUREMENTS AND MAIN RESULTS: Patients underwent colorectal resection for
colorectal endometriosis from February 2009 to November 2012. Nineteen patients
(22%) had multifocal lesions, and 11 patients (13%) had multicentric lesions.
Six patients (7%) had both multifocal and multicentric lesions. The sensitivity,
specificity, and positive and negative likelihood ratios (LRs) of MRI for the
diagnosis of multifocal lesions were 0.58, 0.84, 3.55, and 0.5, respectively.
The sensitivity, specificity, and positive and negative LRs of the CT enema for
the diagnosis of multifocal lesions were 0.64, 0.86, 4.56, and 0.4,
respectively. The sensitivity, specificity, and positive LR of MRI for the
diagnosis of multicentric lesions were 1, 0.88, and 8.4, respectively. The
sensitivity, specificity, and positive and negative LRs of MRI for the diagnosis
of multicentric lesions were 0.46, 0.92, 5.6, and 0.59, respectively. No
difference was observed between MRI and the CT enema for the diagnosis of
multifocal and multicentric colorectal endometriosis. The interobserver
agreement was good for MRI and the CT enema (κ = 0.45 and 0.45) for
multifocality, and it was poor for both MRI and the CT enema (κ = 0.32 and 0.34)
for multicentricity.
CONCLUSIONS: Both MRI and the CT enema were able to diagnose multifocal and
multicentric bowel endometriosis with similar accuracy. OBJECTIVES: The aim of study was to compare the accuracy between rectal water
contrast transvaginal ultrasound (RWC-TVS) and double-contrast barium enema
(DCBE) in evaluating the bowel endometriosis presence as well as its extent.
DESIGN AND SETTING: 198 patients at reproductive age with suspicious bowel
endometriosis were included. Physicians in two groups specialised at
endometriosis performed RWC-TVS as well as DCBE before laparoscopy and both
groups were blinded to other groups' results. Findings from RWC-TVS or DCBE were
compared with histological results. The severity of experienced pain severity
through RWC-TVS or DCBE was assessed by an analogue scale of 10 cm.
RESULTS: In total, 110 in 198 women were confirmed to have endometriosis nodules
in the bowel by laparoscopy as well as histopathology. For bowel endometriosis
diagnosis, DCBE and RWC-TVS demonstrated sensitivities of 96.4% and 88.2%,
specificities of 100% and 97.3%, positive prediction values of 100% and 98.0%,
negative prediction values of 98.0% and 88.0%, accuracies of 98.0% and
92.4%, respectively. DCBE was related to more tolerance than RWC-TVS.
CONCLUSIONS: RWC-TVS and DCBE demonstrated similar accuracies in the bowel
endometriosis diagnosis; however, patients showed more tolerance for RWC-TVS
than those with DCBE. Bowel endometriosis affects between 3.8% and 37% of women with endometriosis.
The evaluation of symptoms and clinical examination are inadequate for an
accurate diagnosis of intestinal endometriosis. Transvaginal ultrasonography is
the first line investigation in patients with suspected bowel endometriosis and
allows accurate determination of the presence of the disease. Radiological
techniques (such as magnetic resoce imaging and multidetector computerized
tomography enteroclysis) are useful for estimating the extent of bowel
endometriosis. Hormonal therapies (progestins, gonadotropin releasing hormone
analogues and aromatase inhibitors) significantly improve pain and intestinal
symptoms in patients with bowel stenosis less than 60% and who do not wish to
conceive. However, hormonal therapies may not prevent the progression of bowel
endometriosis and, therefore, patients receiving long-term treatment should be
periodically monitored. Surgical excision of bowel endometriosis should be
offered to symptomatic patients with bowel stenosis greater than 60%. Intestinal
endometriotic nodules may be excised by nodulectomy or segmental resection. Both
surgical procedures improve pain, intestinal symptoms and fertility. Nodulectomy
may be associated with a lower rate of complications. INTRODUCTION: Intestinal endometriosis is considered the most severe form of
deep endometriosis, the rectosigmoid being involved in about 90% of cases of
bowel infiltration. Transvaginal sonography (TVS) and magnetic resoce imaging
(MRI) have been used for noninvasive diagnosis and preoperative mapping of
rectosigmoid endometriosis (RE), but no consensus has been reached so far
regarding which method is the most accurate in this setting.
OBJECTIVE: We aimed at performing a systematic review and meta-analysis to
compare the accuracy of TVS versus MRI in the diagnosis of RE in a same
population.
METHODS: A systematic review was conducted in accordance with the PRISMA
guidelines. Studies were identified by searching the MEDLINE, Embase, and LILACS
databases, as well the reference lists of retrieved articles, through February
2019. We included all cross-sectional studies that evaluated the accuracy of TVS
versus MRI in the diagnosis of RE within a same sample of subjects and that used
surgical findings with histological confirmation as the gold standard. The
QUADAS-2 instrument was used to evaluate study quality. Sensitivity,
specificity, positive likelihood ratios (LR+), and negative likelihood ratios
(LR-) for the diagnosis of RE were calculated. This study is registered with
PROSPERO, number CRD42017064378.
RESULTS: Eight studies (n = 1132) were included in the meta-analysis. The pooled
sensitivity, specificity, LR+, and LR- values of MRI for RE were 90% (95% CI,
87-92%), 96% (95% CI, 94-97%), 17.26 (95% CI, 3.57-83.50), and 0.15 (95% CI,
0.10-0.23); values of TVS were 90% [95% CI, 87-92%], 96% (95% CI, 94-97%), 20.66
(95% CI, 8.71-49.00) and 0.12 (95% CI, 0.08-0.20), respectively. Areas under the
S-ROC curves (AUC) showed no statistically significant differences between MRI
(AUC = 0.948) and TVS (AUC = 0.930) in the diagnosis of RE (P = 0.13). Moreover,
considering the average prevalence among the studies of 47.3%, both methods
demonstrated similarly high positive post-test probabilities (93.9% for TVS and
94.8% for MRI), and the combined use of them yielded a post-test probability of
99.6%.
CONCLUSION: MRI and TVS have similarly high accuracy and positive post-test
probabilities in the noninvasive diagnosis of RE. Combination of MRI and TVS may
increase even further the positive post-test probabilities to near 100%. Double-contrast barium enema (DCBE), transrectal endoscopic ultrasonography
(REU), multidetector computerized tomography enema (MDCT-e), and computed
tomography colonoscopy (CTC) have been successfully used for the diagnosis of
bowel endometriosis. DCBE provides a complete overview of the entire colon and
allows detecting cecal nodules. The accuracy of DCBE is operator dependent and,
thus, it may have low specificity. It does not allow identifying the cause of
the mass effect. DCBE requires the administration of barium and exposure to
radiation. REU precisely estimates the distance between the rectosigmoid nodule
and the anal verge. However, it allows investigating only the distal part of
rectosigmoid, it misses anterior pelvic lesions, and it has poor sensitivity for
the diagnosis of endometriomas. MDCT-e is accurate and reproducible in
diagnosing intestinal endometriosis and in assessing its characteristics: the
largest diameter of the nodule, the distance between the distal part of the
nodule and the anal verge, and depth of infiltration of endometriosis in the
intestinal wall. MDCT-e requires the administration of iodinated contrast medium
(CM) and the exposure to radiations. CTC has good performance in the diagnosis
of rectosigmoid endometriosis. It allows estimating the degree of intestinal
stenosis CTC, and the distance between the intestinal endometriotic nodule and
the anal verge. It requires exposure to radiations, and it may require the
administration of an iodinated CM. INTRODUCTION: Surgical excision of deep infiltrating endometriosis (DIE) is
complex and associated with morbidity. Diagnostic imaging plays an important
role in the preoperative workup. We sought to determine the utility of single
sagittal T2-weighted MRI motion sequence in the preoperative assessment of
pelvic mobility in patients with endometriosis.
METHODS: An observational study at a single tertiary public referral centre in
Australia. Eighty-one MRI studies from 1 May 2019 to 3 December 2019, were
enrolled. Studies were included if they were performed to stage endometriosis,
including a T2-weighted motion series, adequately covering a uterus, cervix and
rectum. Fifty-seven studies met inclusion criteria. The reference standard was a
contemporaneous transvaginal ultrasound (TVUS) reporting on pelvic organ
mobility. Three subspecialist radiologists were then blindly asked to identify,
on the cine loop: rectouterine immobility, superficial endometriosis (pelvic
bowel adhesions), rectosigmoid Deep Infiltrating Endometriosis (DIE). Fleiss'
Kappa assessed interobserver agreement. Consensus MRI sensitivity and
specificity were estimated against the reference standard (TVUS).
RESULTS: Median age was 35 years (range 19-51). Forty-three cases had a
contemporaneous TVUS; 14 reporting a sliding sign, 29 with fixed pelves.
Interobserver agreement was 'substantial' (k = 0.79) for absent MRI sliding sign
and 'almost perfect' (k = 0.90) for absence of DIE. Consensus MRI had 90%
sensitivity (95% CI 73-98%) for pelvic immobility at TVUS (absent sliding sign).
Interobserver agreement and consensus MRI sensitivity were higher for adhesions
and immobility than normal findings.
CONCLUSION: An MRI motion sequence can identify patients with pelvic adhesions
and immobility, helping determine surgical difficulty when TVUS is not
diagnostic. |
When did FDA approve the first B-cell maturation antigen-targeted CAR-T cell therapy? | FDA approved the first B-cell maturation antigen-targeted CAR-T cell therapy on March 26, 2021. | Chimeric antigen receptor T (CART) cells targeting CD19 have shown promising
results in the treatment of chronic lymphocytic leukemia (CLL). However,
efficacy seems to be inferior compared to diffuse large B-cell lymphoma or acute
lymphoblastic leukemia. Impaired T-cell fitness of CLL patients may be involved
in treatment failure. Less-differentiated naïve-like T cells play an important
role in CART expansion and long-term persistence in vivo. These cells are sparse
in CLL patients. Therefore, optimization of CART cell production protocols
enriching less differentiated T cell subsets may overcome treatment resistance.
The B-cell receptor inhibitor ibrutinib targeting Bruton's tyrosine kinase (BTK)
is approved for the treatment of CLL. Besides BTK, ibrutinib additionally
inhibits interleukin-2-inducible T-cell kinase (ITK) which is involved in T-cell
differentiation. To evaluate the effect of ibrutinib on CART cell production,
peripheral blood mononuclear cells from nine healthy donors and eight CLL
patients were used to generate CART cells. T-cell expansion and phenotype,
expression of homing and exhaustion makers as well as functionality of CART
cells were evaluated. CART cell generation in the presence of ibrutinib resulted
in increased cell viability and expansion of CLL patient-derived CART cells.
Furthermore, ibrutinib enriched CART cells with less-differentiated naïve-like
phenotype and decreased expression of exhaustion markers including PD-1, TIM-3
and LAG-3. In addition, ibrutinib increased the cytokine release capacity of CLL
patient-derived CART cells. In summary, BTK/ITK inhibition with ibrutinib during
CART cell culture can improve yield and function of CLL patient-derived CART
cell products. Chimeric antigen receptor (CAR) T-cell therapy has quickly emerged as a highly
promising treatment for patients with relapsed and refractory multiple myeloma.
There are numerous candidates under development, each with their unique
characteristics and points of differentiation. The most recent US Food and Drug
Administration approval of the first B-cell maturation antigen-targeted CAR-T
cell therapy on March 26, 2021, has paved a path forward for the eventual
evaluation of more of these investigational agents undergoing clinical trials.
Herein, we highlight, from a clinical development perspective, the CAR-T cell
therapies farthest along in development with updated data from the American
Society of Hematology 2020 annual meeting. We also discuss potential paths of
overcoming resistance to these therapies and the future direction for CAR-T cell
therapeutics in multiple myeloma. |
Describe the N6-methyladenosine RNA modification in AML | The N6-methyladenosine RNA modification in AML is a nucleotide that is not normally found in the DNA of cancer cells. This nucleotide has been shown to have an effect on the cell's ability to divide. | PURPOSE OF REVIEW: In recent years, the N6-methyladenosine (m6A) modification of
RNA has been shown to play an important role in the development of acute myeloid
leukemia (AML) and the maintece of leukemic stem cells (LSCs). In this review
we summarise the recent findings in the field of epitranscriptomics related to
m6A and its relevance in AML.
RECENT FINDINGS: Recent studies have focused on the role of m6A regulators in
the development of AML and their potential as translational targets. The writer
Methyltransferase Like 3 and its binding partner Methyltransferase Like 14, as
well as the reader YTH domain-containing family protein 2, were shown to be
vital for LSC survival, and their loss has detrimental effects on AML cells.
Similar observations were made with the demethylases fat mass and
obesity-associated protein and AlkB homologue 5 RNA demethylase. Of importance,
loss of any of these genes has little to no effect on normal hemopoietic stem
cells, suggesting therapeutic potential.
SUMMARY: The field of epitranscriptomics is still in its infancy and the
importance of m6A and other RNA-modifications in AML will only come into sharper
focus. The development of therapeutics targeting RNA-modifying enzymes may open
up new avenues for treatment of such maligcies. |
Does trimetazidine protect from myocardial injury after percutaneous coronary intervention? | Oral trimetazidine 35 mg twice daily over several years in patients receiving optimal medical therapy, after successful PCI, does not influence the recurrence of angina or the outcome; these findings should be taken into account when considering the place of trimetazidine in clinical practice. | |
When is the drug Ivermectin used? | Ivermectin (IVM) has been well known for its role in the treatment of parasitic diseases, due to its effect on glutamate-gated chloride channels. These same channels are also present in the mosquito vector, and thus, research has focused on the insecticidal effects of this drug. | The aim of this study was to compare the economic revenue related to the use of
low- or high-efficacy anthelmintic drugs within suppressive or strategic schemes
of treatment in growing heifers. Heifers raised in a semi-intensive grazing
system in southern Brazil were used. Levamisole and ivermectin were selected as
the high- and the low-efficacy drugs, respectively, based on a previous efficacy
test. Subsequently, these drugs were used within strategic (Strat; four times
per year) or suppressive (Supp; once a month) treatment regimens in the heifers,
and their liveweight and eggs per gram of feces counts were monthly evaluated
during a 13-month period. The total costs of the treatments and their
cost-benefit ratio in regard to liveweight gain were calculated. Final mean
liveweight gains (kg) observed were 126.7 (Strat-Low), 133.6 (Supp-Low), 141.3
(Strat-High), 142.9 (Supp-High), and 125.8 (Control). Treatments with a
high-efficacy drug resulted in monetary gains of US$ 19.56 (Strat-High) and US$
14.98 (Supp-High), but Supp-Low and Strat-Low treatments caused economic losses.
Total cost of the efficacy test (US$ 374.79) could be paid by the additional
liveweight gain of 20 heifers from the Strat-High group. These results showed
that it would be preferable not to treat the heifers against GIN if compared
with treating them with a low-efficacy drug. In addition, we showed that the use
of four treatments per year with a high-efficacy drug-selected by efficacy
test-resulted in a profitable management to control GIN in growing heifers
raised in a semi-intensive gazing system in southern Brazil. In developing countries, low-cost control and treatment programs that offer
combined approaches against diseases and their vectors are certainly needed.
Ivermectin (IVM) has been well known for its role in the treatment of parasitic
diseases, due to its effect on glutamate-gated chloride channels. These same
channels are also present in the mosquito vector, and thus, research has focused
on the insecticidal effects of this drug. Possible alternative mechanisms of IVM
on the physiology of mosquitoes, however, have not been sufficiently elaborated.
We assessed the protease activity, lipid peroxidation, and local expression of
STAT, p53, caspase-3, and Bax markers to study the effect of this antibiotic on
digestion and immunity in Culex pipiens. Sugar- and blood-feeding assays were
employed to investigate the potential influence of blood feeding on the dynamics
of these parameters. IVM was found to have an effect on protease activity, lipid
peroxidation as well as the expression of different markers investigated in this
work. The focus on the detailed effect of this drug certainly opens the gate to
broadening the spectrum of IVM and expanding its health and economic benefit,
especially that it is relatively more affordable than other antibiotics on the
market. Publisher: OBJECTIF: L'ivermectine est sûr et largement utilisé pour traiter les
helminthiases. Il tue également les arthropodes se nourrissant sur les sujets
traités, y compris les vecteurs du paludisme. Ainsi, l'administration en masse
d'ivermectine en tant qu'outil supplémentaire de lutte contre le paludisme est
actuellement évaluée par l'OMS. Comme les données in vitro, les expériences sur
animaux et les observations épidémiologiques suggèrent que l'ivermectine a un
effet direct sur les stades hépatiques du parasite du paludisme, cette étude a
été conçue pour évaluer l'effet prophylactique de l'ivermectine sur l'infection
paludéenne humaine par Plasmodium falciparum contrôlée. MÉTHODES: Quatre
volontaires ont été randomisés pour un placebo et 8 volontaires ont été
randomisés pour recevoir de l'ivermectine à 0,4 mg/kg en une fois par voie
orale, 2 heures avant d'être expérimentalement infectés par voie intraveineuse
avec 3.200 sporozoïtes de P. falciparum. Le critère d'évaluation principal était
le temps à la parasitémie détectée par un frottis sanguin épais positif. Une
RT-qPCR a été réalisée en parallèle. RÉSULTATS: Tous les volontaires sauf un
sont devenus positifs pour les frottis sanguins épais entre le jour 11 et le
jour 12 après l'infection et il n'y avait aucun effet significatif de
l'ivermectine sur la parasitémie.
CONCLUSION: L'ivermectine - à la dose utilisée - n'a aucune activité
cliniquement pertinente contre les stades pré-érythrocytaires de P. falciparum. |
What is the function of a DEAD box protein? | DEAD-box helicases are ubiquitous in RNA-mediated processes and function by coupling cycles of ATP binding and hydrolysis to changes in affinity for single-stranded RNA. | RNA secondary structure is a critical determit of RNA function in ribosome
assembly, pre-mRNA splicing, mRNA translation and RNA stability. The 'DEAD/H'
family of putative RNA helicases may help regulate these processes by utilizing
intrinsic RNA-dependent ATPase activity to catalyze conformational changes in
RNA secondary structure. To investigate the repertoire of DEAD/H box proteins
expressed in mammals, we used PCR techniques to clone from mouse erythroleukemia
(MEL) cells three new DEAD box cDNAs with high similarity to known yeast
(Saccharomyces cerevisiae) genes. mDEAD2 and mDEAD3 (mouse DEAD box proteins)
are > 95% identical to mouse PL10 but exhibit differential tissue-specific
expression patterns; mDEAD2 and mDEAD3 are also approx. 70% identical (at the aa
level) to yeast DED1 and DBP1 proteins. Members of this DEAD box subclass
contain C-terminal domains with high content of Arg, Ser, Gly and Phe,
reminiscent of the RS domain in several Drosophila and mammalian splicing
factors. mDEAD5 belongs to a second class related to translation initiation
factors from yeast (TIF1/TIF2) and mammals (eIF-4A); this class contains a novel
conserved peptide motif not found in other DEAD box proteins. Northern blotting
shows that mDEAD5 is differentially expressed in testis vs. somatic tissues.
Thus, mouse erythroid cells produce two highly conserved families of putative
RNA helicases likely to play important roles in RNA metabolism and gene
expression. DEAD box proteins are putative RNA helicases that function in all aspects of RNA
metabolism, including translation, ribosome biogenesis, and pre-mRNA splicing.
Because many processes involving RNA metabolism are spatially organized within
the cell, we examined the subcellular distribution of a human DEAD box protein,
DDX1, to identify possible biological functions. Immunofluorescence labeling of
DDX1 demonstrated that in addition to widespread punctate nucleoplasmic
labeling, DDX1 is found in discrete nuclear foci approximately 0.5 microm in
diameter. Costaining with anti-Sm and anti-promyelocytic leukemia (PML)
antibodies indicates that DDX1 foci are frequently located next to Cajal
(coiled) bodies and less frequently, to PML bodies. Most importantly, costaining
with anti-CstF-64 antibody indicates that DDX1 foci colocalize with cleavage
bodies. By microscopic fluorescence resoce energy transfer, we show that
labeled DDX1 resides within a Förster distance of 10 nm of labeled CstF-64
protein in both the nucleoplasm and within cleavage bodies.
Coimmunoprecipitation analysis indicates that a proportion of CstF-64 protein
resides in the same complex as DDX1. These studies are the first to identify a
DEAD box protein associating with factors involved in 3'-end cleavage and
polyadenylation of pre-mRNAs. The Neurospora crassa CYT-18 protein, the mitochondrial tyrosyl-tRNA synthetase,
functions in splicing group I introns by inducing formation of the catalytically
active RNA structure. Here, we identified a DEAD-box protein (CYT-19) that
functions in concert with CYT-18 to promote group I intron splicing in vivo and
vitro. CYT-19 does not bind specifically to group I intron RNAs and instead
functions as an ATP-dependent RNA chaperone to destabilize nonnative RNA
structures that constitute kinetic traps in the CYT-18-assisted RNA-folding
pathway. Our results demonstrate that a DExH/D-box protein has a specific,
physiologically relevant chaperone function in the folding of a natural RNA
substrate. RNA helicases of the DEAD-box and related families have been found to be
required for all processes involving RNA molecules. Biochemical and genetic
analyses have shown that at least two RNA helicases are required for translation
initiation in yeast. Although it is generally believed that these enzymes are
necessary to unwind secondary structures in the 5' untranslated region of mRNAs,
their exact role has not been convincingly shown. We discuss here our present
knowledge of the function of eIF4A and Ded1p, two DEAD-box proteins required for
translation in eukaryotic cells. DEAD box proteins catalyze the ATP-dependent unwinding of double-stranded RNA
(dsRNA). In addition, they facilitate protein displacement and remodeling of RNA
or RNA/protein complexes. Their hallmark feature is local destabilization of RNA
duplexes. Here, we summarize current data on the DEAD box protein mechanism and
present a model for RNA unwinding that integrates recent data on the effect of
ATP analogs and mutations on DEAD box protein activity. DEAD box proteins share
a conserved helicase core with two flexibly linked RecA-like domains that
contain all helicase signature motifs. Variable flanking regions contribute to
substrate binding and modulate activity. In the presence of ATP and RNA, the
helicase core adopts a compact, closed conformation with extensive interdomain
contacts and high affinity for RNA. In the closed conformation, the RecA-like
domains form a catalytic site for ATP hydrolysis and a continuous RNA binding
site. A kink in the backbone of the bound RNA locally destabilizes the duplex.
Rearrangement of this initial complex generates a hydrolysis- and
unwinding-competent state. From this complex, the first RNA strand can
dissociate. After ATP hydrolysis and phosphate release, the DEAD box protein
returns to a low-affinity state for RNA. Dissociation of the second RNA strand
and reopening of the cleft in the helicase core allow for further catalytic
cycles. The yeast DEAD box protein Mss116p is a general RNA chaperone that functions in
mitochondrial group I and II intron splicing, translational activation, and RNA
end processing. Here we determined high-resolution X-ray crystal structures of
Mss116p complexed with an RNA oligonucleotide and ATP analogs AMP-PNP,
ADP-BeF(3)(-), or ADP-AlF(4)(-). The structures show the entire helicase core
acting together with a functionally important C-terminal extension. In all
structures, the helicase core is in a closed conformation with a wedge alpha
helix bending RNA 3' of the central bound nucleotides, as in previous DEAD box
protein structures. Notably, Mss116p's C-terminal extension also bends RNA 5' of
the central nucleotides, resulting in RNA crimping. Despite reported functional
differences, we observe few structural changes in ternary complexes with
different ATP analogs. The structures constrain models of DEAD box protein
function and reveal a strand separation mechanism in which a protein uses two
wedges to act as a molecular crimper. DEAD-box proteins are ubiquitous in RNA-mediated processes and function by
coupling cycles of ATP binding and hydrolysis to changes in affinity for
single-stranded RNA. Many DEAD-box proteins use this basic mechanism as the
foundation for a version of RNA helicase activity, efficiently separating the
strands of short RNA duplexes in a process that involves little or no
translocation. This activity, coupled with mechanisms to direct different
DEAD-box proteins to their physiological substrates, allows them to promote RNA
folding steps and rearrangements and to accelerate remodeling of RNA–protein
complexes. This review will describe the properties of DEAD-box proteins as RNA
helicases and the current understanding of how the energy from ATPase activity
is used to drive the separation of RNA duplex strands. It will then describe how
the basic biochemical properties allow some DEAD-box proteins to function as
chaperones by promoting RNA folding reactions, with a focus on the self-splicing
group I and group II intron RNAs. DEAD-box proteins are the largest family of nucleic acid helicases, and are
crucial to RNA metabolism throughout all domains of life. They contain a
conserved 'helicase core' of two RecA-like domains (domains (D)1 and D2), which
uses ATP to catalyse the unwinding of short RNA duplexes by non-processive,
local strand separation. This mode of action differs from that of translocating
helicases and allows DEAD-box proteins to remodel large RNAs and RNA-protein
complexes without globally disrupting RNA structure. However, the structural
basis for this distinctive mode of RNA unwinding remains unclear. Here,
structural, biochemical and genetic analyses of the yeast DEAD-box protein
Mss116p indicate that the helicase core domains have modular functions that
enable a novel mechanism for RNA-duplex recognition and unwinding. By
investigating D1 and D2 individually and together, we find that D1 acts as an
ATP-binding domain and D2 functions as an RNA-duplex recognition domain. D2
contains a nucleic-acid-binding pocket that is formed by conserved DEAD-box
protein sequence motifs and accommodates A-form but not B-form duplexes,
providing a basis for RNA substrate specificity. Upon a conformational change in
which the two core domains join to form a 'closed state' with an ATPase active
site, conserved motifs in D1 promote the unwinding of duplex substrates bound to
D2 by excluding one RNA strand and bending the other. Our results provide a
comprehensive structural model for how DEAD-box proteins recognize and unwind
RNA duplexes. This model explains key features of DEAD-box protein function and
affords a new perspective on how the evolutionarily related cores of other RNA
and DNA helicases diverged to use different mechanisms. DEAD-box helicases catalyze the ATP-dependent unwinding of RNA duplexes. They
share a helicase core formed by two RecA-like domains that carries a set of
conserved motifs contributing to ATP binding and hydrolysis, RNA binding and
duplex unwinding. The translation initiation factor eIF4A is the founding member
of the DEAD-box protein family, and one of the few examples of DEAD-box proteins
that consist of a helicase core only. It is an RNA-stimulated ATPase and a
non-processive helicase that unwinds short RNA duplexes. In the catalytic cycle,
a series of conformational changes couples the nucleotide cycle to RNA
unwinding. eIF4A has been considered a paradigm for DEAD-box proteins, and
studies of its function have revealed the governing principles underlying the
DEAD-box helicase mechanism. However, as an isolated helicase core, eIF4A is
rather the exception, not the rule. Most helicase modules in other DEAD-box
proteins are modified, some by insertions into the RecA-like domains, and the
majority by N- and C-terminal appendages. While the basic catalytic function
resides within the helicase core, its modulation by insertions, additional
domains or a network of interaction partners generates the diversity of DEAD-box
protein functions in the cell. This review summarizes the current knowledge on
eIF4A and its regulation, and discusses to what extent eIF4A serves as a model
DEAD-box protein. Members of the DEAD box family of RNA helicases, which are characterised by the
presence of twelve conserved motifs (including the signature D-E-A-D motif)
within a structurally conserved 'helicase' core, are involved in all aspects of
RNA metabolism. Apart from unwinding RNA duplexes, which established these
proteins as RNA helicases, DEAD box proteins have been shown to also catalyse
RNA annealing and to displace proteins from RNA. DEAD box proteins generally act
as components of large multi-protein complexes and it is thought that
interactions, via their divergent N- and C-terminal extensions, with other
factors in the complexes may be responsible for the many different functions
attributed to these proteins. In addition to their established crucial roles in
the manipulation of RNA structure, it is becoming increasingly clear that
several members of the DEAD box family act as regulators of transcription. In
this review I shall focus on DDX5 (p68) and the highly related DDX17 (p72), two
proteins for which there is a large body of evidence demonstrating that they
function in transcriptional regulation. This article is part of a Special Issue
entitled: The Biology of RNA helicases - Modulation for life. DDX3 belongs to the DEAD-box proteins, a large family of ATP-dependent RNA
helicases that participate in all aspects of RNA metabolism. Human DDX3 is a
component of several messenger ribonucleoproteins that are found in the
spliceosome, the export and the translation initiation machineries but also in
different cytoplasmic mRNA granules. DDX3 has been involved in several cellular
processes such as cell cycle progression, apoptosis, cancer, innate immune
response, and also as a host factor for viral replication. Interestingly, not
all these functions require the catalytic activities of DDX3 and thus, the
precise roles of this apparently multifaceted protein remain largely obscure.
The aim of this review is to provide a rapid and critical overview of the
structure and functions of DDX3 with a particular emphasis on its role during
mRNA metabolism. DEAD-box proteins, a large class of RNA-dependent ATPases, regulate all aspects
of gene expression and RNA metabolism. They can facilitate dissociation of RNA
duplexes and remodeling of RNA-protein complexes, serve as ATP-dependent
RNA-binding proteins, or even anneal duplexes. These proteins have highly
conserved sequence elements that are contained within two RecA-like domains;
consequently, their structures are nearly identical. Furthermore, crystal
structures of DEAD-box proteins with bound RNA reveal interactions exclusively
between the protein and the RNA backbone. Together, these findings suggest that
DEAD-box proteins interact with their substrates in a nonspecific manner, which
is confirmed in biochemical experiments. Nevertheless, this contrasts with the
need to target these enzymes to specific substrates in vivo. Using the DEAD-box
protein Rok1 and its cofactor Rrp5, which both function during maturation of the
small ribosomal subunit, we show here that Rrp5 provides specificity to the
otherwise nonspecific biochemical activities of the Rok1 DEAD-domain. This
finding could reconcile the need for specific substrate binding of some DEAD-box
proteins with their nonspecific binding surface and expands the potential roles
of cofactors to specificity factors. Identification of helicase cofactors and
their RNA substrates could therefore help define the undescribed roles of the 19
DEAD-box proteins that function in ribosome assembly. BACKGROUND: Vasa is a member of the DEAD-box protein family that plays an
indispensable role in mammalian spermatogenesis, particularly during meiosis.
Bovine vasa homology (Bvh) of Bos taurus has been reported, however, its
function in bovine testicular tissue remains obscure. This study aimed to reveal
the functions of Bvh and to determine whether Bvh is a candidate gene in the
regulation of spermatogenesis in bovine, and to illustrate whether its
transcription is regulated by alternative splicing and DNA methylation.
RESULTS: Here we report the molecular characterization, alternative splicing
pattern, expression and promoter methylation status of Bvh. The full-length
coding region of Bvh was 2190 bp, which encodes a 729 amino acid (aa) protein
containing nine consensus regions of the DEAD box protein family. Bvh is
expressed only in the ovary and testis of adult cattle. Two splice variants were
identified and termed Bvh-V4 (2112 bp and 703 aa) and Bvh-V45 (2040 bp and 679
aa). In male cattle, full-length Bvh (Bvh-FL), Bvh-V4 and Bvh-V45 are
exclusively expressed in the testes in the ratio of 2.2:1.6:1, respectively.
Real-time PCR revealed significantly reduced mRNA expression of Bvh-FL, Bvh-V4
and Bvh-V45 in testes of cattle-yak hybrids, with meiotic arrest compared with
cattle and yaks with normal spermatogenesis (P < 0.01). The promoter methylation
level of Bvh in the testes of cattle-yak hybrids was significantly greater than
in cattle and yaks (P < 0.01).
CONCLUSION: In the present study, Bvh was isolated and characterized. These data
suggest that Bvh functions in bovine spermatogenesis, and that transcription of
the gene in testes were regulated by alternative splice and promoter
methylation. DEAD-box proteins catalyze the ATP-dependent unwinding of RNA duplexes and
accompany RNA molecules throughout their cellular life. Conformational changes
in the helicase core of DEAD-box proteins are intimately linked to duplex
unwinding. In the absence of ligands, the two RecA domains of the helicase core
are separated. ATP and RNA binding induces a closure of the cleft between the
RecA domains that is coupled to the distortion of bound RNA, leading to duplex
destabilization and dissociation of one RNA strand. Reopening of the helicase
core occurs after ATP hydrolysis and is coupled to phosphate release and
dissociation of the second RNA strand.Fluorescence spectroscopy provides an
array of approaches to study intermolecular interactions, local structural
rearrangements, or large conformational changes of biomolecules. The
fluorescence intensity of a fluorophore reports on its environment, and
fluorescence anisotropy reflects the size of the molecular entity the
fluorophore is part of. Fluorescence intensity and anisotropy are therefore
sensitive probes to report on binding and dissociation events. Fluorescence
resoce energy transfer (FRET) reports on the distance between two
fluorophores and thus on conformational changes. Single-molecule FRET
experiments reveal the distribution of conformational states and the kinetics of
their interconversion. This chapter summarizes fluorescence approaches for
monitoring individual aspects of DEAD-box protein activity, from nucleotide and
RNA binding and RNA unwinding to protein and RNA conformational changes in the
catalytic cycle, and illustrates exemplarily how fluorescence-based methods have
contributed to understanding the mechanism of DEAD-box helicase-catalyzed RNA
unwinding. VASA is a member of the DEAD-box protein family that plays an indispensable role
in mammalian spermatogenesis, particularly during meiosis. In the present study,
we isolated, sequenced, and characterized VASA gene in buffalo testis. Here, we
demonstrated that VASA mRNA is expressed as multiple isoforms and uses four
alternative transcriptional start sites (TSSs) and four different
polyadenylation sites. The TSSs identified by 5'-RNA ligase-mediated rapid
amplification of cDNA ends (RLM-5'-RACE) were positioned at 48, 53, 85, and 88
nucleotides upstream relative to the translation initiation codon. 3'-RACE
experiment revealed the presence of tandem polyadenylation signals, which lead
to the expression of at least four different 3'-untranslated regions (209, 233,
239 and 605 nucleotides). The full-length coding region of VASA was 2190 bp,
which encodes a 729 amino acid (aa) protein containing nine consensus regions of
the DEAD box protein family. VASA variants are highly expressed in testis of
adult buffalo. We found five variants, one full length VASA (729 aa) and four
splice variants VASA 2, 4, 5, 6 (683, 685, 679, 703 aa). The expression level of
VASA 1 was significantly higher than rest of all (P < 0.05) except VASA 6. The
relative ratio for VASA 1:2:4:5:6 was 100:1.0:1.6:0.9:48. DEAD-box proteins are nonprocessive RNA helicases that play diverse roles in
cellular processes. The Neurospora crassa DEAD-box protein CYT-19 promotes
mitochondrial group I intron splicing and functions as a general RNA chaperone.
CYT-19 includes a disordered, arginine-rich "C-tail" that binds RNA, positioning
the helicase core to capture and unwind nearby RNA helices. Here we probed the
C-tail further by varying the number and positions of arginines within it. We
found that removing sets of as few as four of the 11 arginines reduced RNA
unwinding activity (kcat/KM) to a degree equivalent to that seen upon removal of
the C-tail, suggesting that a minimum or "threshold" number of arginines is
required. In addition, a mutant with 16 arginines displayed RNA unwinding
activity greater than that of wild-type CYT-19. The C-tail modifications
impacted unwinding only of RNA helices within constructs that included an
adjacent helix or structured RNA element that would allow C-tail binding,
indicating that the helicase core remained active in the mutants. In addition,
changes in RNA unwinding efficiency of the mutants were mirrored by changes in
functional RNA affinity, as determined from the RNA concentration dependence of
ATPase activity, suggesting that the C-tail functions primarily to increase RNA
affinity. Interestingly, the salt concentration dependence of RNA unwinding
activity is unaffected by C-tail composition, suggesting that the C-tail uses
primarily hydrogen bonding, not electrostatic interactions, to bind
double-stranded RNA. Our results provide insights into how an unstructured
C-tail contributes to DEAD-box protein activity and suggest parallels with other
families of RNA- and DNA-binding proteins. RNA helicases catalyze the ATP-dependent destabilization of RNA duplexes.
DEAD-box helicases share a helicase core that mediates ATP binding and
hydrolysis, RNA binding and unwinding. Most members of this family contain
domains flanking the core that can confer RNA substrate specificity and guide
the helicase to a specific RNA. However, the in vivo RNA substrates of most
helicases are currently not defined. The DEAD-box helicase Hera from Thermus
thermophilus contains a helicase core, followed by a dimerization domain and an
RNA binding domain that folds into an RNA recognition motif (RRM). The RRM
mediates high affinity binding to an RNA hairpin, and an adjacent duplex is then
unwound by the helicase core. Hera is a cold-shock protein, and has been
suggested to act as an RNA chaperone under cold-shock conditions. Using
crosslinking immunoprecipitation of Hera/RNA complexes and sequencing, we show
that Hera binds to a large fraction of T. thermophilus RNAs under normal-growth
and cold-shock conditions without a strong sequence preference, in agreement
with a structure-specific recognition of RNAs and a general function in RNA
metabolism. Under cold-shock conditions, Hera is recruited to RNAs with high
propensities to form stable secondary structures. We show that selected RNAs
identified, including a set of tRNAs, bind to Hera in vitro, and activate the
Hera helicase core. Gene ontology analysis reveals an enrichment of genes
related to translation, including mRNAs of ribosomal proteins, tRNAs, tRNA
ligases, and tRNA-modifying enzymes, consistent with a key role of Hera in
ribosome and tRNA metabolism. DEAD-box (DDX) proteins belong to the largest subfamily of RNA helicase SF2,
which contributes to all biological processes of RNA metabolism in the plant
kingdom. Till now, no significant data are available regarding studies on DDX in
Somatic Embryogenesis (SE) of woody plants. It is important to investigate the
biological function of the DlDDX family in longan SE. Thus, a comprehensive
analysis of 58 longan DEAD-box (DlDDX) genes characterization was performed by
genome-wide identification and transcript abundance validation analysis.
Homologous evolution has revealed that some DlDDXs in longan had high sequence
similarity with Mus musculus, Citrus and Saccharomyces cerevisiae, indicating
that DlDDXs were highly conservative in the animal, plant, and microorganism.
Remarkably, gene duplication, purifying selection, and alternative splicing
events, and new auxiliary domains have likely contributed to the functional
evolution of DlDDX, indicating that DlDDX appeared neofunctionalization in
longan. Besides, DlDDX3, 15, 28, 36 might interact with protein complex (MAC3A,
MAC3B, CDC5, CBP20) of miRNA biosynthesis. Notably, DlDDX28 contained a novel
auxiliary domain (CAF-1 p150), which might contribute to DNA demethylation in
longan early SE. 4 DlDDX genes significantly expressed not only in early SE and
zygotic embryogenesis (ZE) but also up-regulated at high levels in 'Honghezi'
and 'Quanlongbaihe' with abortive seeds, which are of great significance.
Moreover, some DlDDXs presented abiotic stress-response dynamic expression
patterns by ABA, SA, JA, and NaCl treatments during early SE. Hence, DEAD-box is
essential to SE development and seed abortive in longan. |
What is the effect of rHDL-apoE3 on vascular permeability? | rHDL-apoE3 markedly improves vascular permeability as demonstrated by the reduced concentration of Evans Blue dye in tissues such as the stomach, the tongue and the urinary bladder and ameliorated hypercholesterolemia. | INTRODUCTION: Atherosclerotic Coronary Artery Disease (ASCAD) is the leading
cause of mortality worldwide. Novel therapeutic approaches aiming to improve the
atheroprotective functions of High Density Lipoprotein (HDL) include the use of
reconstituted HDL forms containing human apolipoprotein A-I (rHDL-apoA-I). Given
the strong atheroprotective properties of apolipoprotein E3 (apoE3), rHDL-apoE3
may represent an attractive yet largely unexplored therapeutic agent.
OBJECTIVE: To evaluate the atheroprotective potential of rHDL-apoE3 starting
with the unbiased assessment of global transcriptome effects and focusing on
endothelial cell (EC) migration as a critical process in re-endothelialization
and atherosclerosis prevention. The cellular, molecular and functional effects
of rHDL-apoE3 on EC migration-associated pathways were assessed, as well as the
potential translatability of these findings in vivo.
METHODS: Human Aortic ECs (HAEC) were treated with rHDL-apoE3 and total RNA was
analyzed by whole genome microarrays. Expression and phosphorylation changes of
key EC migration-associated molecules were validated by qRT-PCR and Western blot
analysis in primary HAEC, Human Coronary Artery ECs (HCAEC) and the human
EA.hy926 EC line. The capacity of rHDL-apoE3 to stimulate EC migration was
assessed by wound healing and transwell migration assays. The contribution of
MEK1/2, PI3K and the transcription factor ID1 in rHDL-apoE3-induced EC migration
and activation of EC migration-related effectors was assessed using specific
inhibitors (PD98059: MEK1/2, LY294002: PI3K) and siRNA-mediated gene silencing,
respectively. The capacity of rHDL-apoE3 to improve vascular permeability and
hypercholesterolemia in vivo was tested in a mouse model of hypercholesterolemia
(apoE KO mice) using Evans Blue assays and lipid/lipoprotein analysis in the
serum, respectively.
RESULTS: rHDL-apoE3 induced significant expression changes in 198 genes of HAEC
mainly involved in re-endothelialization and atherosclerosis-associated
functions. The most pronounced effect was observed for EC migration, with 42/198
genes being involved in the following EC migration-related pathways: 1) MEK/ERK,
2) PI3K/AKT/eNOS-MMP2/9, 3) RHO-GTPases, 4) integrin. rHDL-apoE3 induced changes
in 24 representative transcripts of these pathways in HAEC, increasing the
expression of their key proteins PIK3CG, EFNB2, ID1 and FLT1 in HCAEC and
EA.hy926 cells. In addition, rHDL-apoE3 stimulated migration of HCAEC and
EA.hy926 cells, and the migration was markedly attenuated in the presence of
PD98059 or LY294002. rHDL-apoE3 also increased the phosphorylation of ERK1/2,
AKT, eNOS and p38 MAPK in these cells, while PD98059 and LY294002 inhibited
rHDL-apoE3-induced phosphorylation of ERK1/2, AKT and p38 MAPK, respectively. LY
had no effect on rHDL-apoE3-mediated eNOS phosphorylation. ID1 siRNA markedly
decreased EA.hy926 cell migration by inhibiting rHDL-apoE3-triggered ERK1/2 and
AKT phosphorylation. Finally, administration of a single dose of rHDL-apoE3 in
apoE KO mice markedly improved vascular permeability as demonstrated by the
reduced concentration of Evans Blue dye in tissues such as the stomach, the
tongue and the urinary bladder and ameliorated hypercholesterolemia.
CONCLUSIONS: rHDL-apoE3 significantly enhanced EC migration in vitro,
predomitly via overexpression of ID1 and subsequent activation of MEK1/2 and
PI3K, and their downstream targets ERK1/2, AKT and p38 MAPK, respectively, and
improved vascular permeability in vivo. These novel insights into the rHDL-apoE3
functions suggest a potential clinical use to promote re-endothelialization and
retard development of atherosclerosis. |
What is inhibited by TH1579? | TH1579 is a best-in-class MTH1 inhibitor. | Author information:
(1)Science for Life Laboratory, Division of Translational Medicine and Chemical
Biology, Department of Medical Biochemistry and Biophysics.
(2)Clinical Proteomics Mass Spectrometry, Department of Oncology-Pathology.
(3)Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of
Translational Medicine and Chemical Biology, Department of Medical Biochemistry
and Biophysics.
(4)Division of Physiological Chemistry I, Department of Medical Biochemistry and
Biophysics, Karolinska Institutet, Stockholm, Sweden.
(5)Molecular Carcinogenesis Group, Department of Histology and Embryology,
School of Medicine, National and Kapodistrian University of Athens, Athens,
Greece.
(6)Sahlgrenska Translational Melanoma Group (SATMEG), Sahlgrenska Cancer Center,
Department of Surgery, Institute of Clinical Sciences, University of Gothenburg
and Sahlgrenska University Hospital, Gothenburg.
(7)Department of Pharmacy and.
(8)Science for Life Laboratory Drug Discovery and Development Platform, ADME of
Therapeutics facility, Department of Phamracy, Uppsala University, Uppsala,
Sweden.
(9)Swedish Toxicology Sciences Research Center, Södertälje, Sweden.
(10)National Bioinformatics Infrastructure Sweden (NBIS), Science for Life
Laboratory, Department of Medicine Solna, Karolinska Institutet, Stockholm.
(11)SP Process Development, Södertälje, Sweden.
(12)Uppsala Drug Optimisation and Pharmaceutical Profiling Platform (UDOPP),
Department of Pharmacy, Uppsala University, Uppsala, Sweden.
(13)Institute of biomedical sciences, Academia Sinica, Taipei-115, Taiwan.
(14)Biomedical Research Foundation of the Academy of Athens, Athens, Greece.
(15)Faculty Institute for Cancer Sciences, Manchester Academic Health Sciences
Centre, University of Manchester, Manchester, UK.
(16)Science for Life Laboratory, Division of Translational Medicine and Chemical
Biology, Department of Medical Biochemistry and Biophysics
[email protected]. |
What is the mechanism of action of Gemogenovatucel-T? | Gemogenovatucel-T is an autologous tumour cell vaccine manufactured from harvested tumour tissue, which specifically reduces expression of furin and downstream TGF-β1 and TGF-β2. | |
What is the Versene Solution used for? | the Versene Solution is used for the detachment of stem cell sheets. | Original modification of the harvest procedure, hypotonic treatment and
slide-making techniques were used to obtain prometaphase spreads of good quality
fitted to G-banding or to FISH. Human blood cultures were synchronized with a
methotrexate block during synthesis, and following this with a thymidine
release. Cells were then proceeded into prometaphase and early metaphase and
were quickly harvested without exposure to colcemid. Following incubation in a
mixture of 0.56% KCl and 1% sodium citrate (1:1) for 20-23 min at room
temperature, cells were fixed in 4 changes of fixative made of 3 parts of
absolute methanol and 1 part of glacial acetic acid. Three or four 100-105
microliters volume of a suspension of fixed cells were blew with a strength
through pasteur pipette tip from a distance 5-6 cm onto chilled superclean
slides wetted by water. These slides were then quickly flame dried. Prior to
staining, prometaphase bearing spreads were held in thermostat overnight at 37
degrees C. Prometaphases were G-banded with the aid of a modified technique
elaborated in the Department of Clinical Genetics, Lund University Hospital
(Sweden). The slides were incubated for 1-4 min at room temperature in 0.01
versene solution, containing 0.011% w/v trypsin (Difco), 0.4 mg/ml D-glucose,
0.17 mg/ml KCl, 1.7 mg/ml NaCl. Following a 15 sec incubation in a solution
containing 1 mg/ml D-glucose, 0.4 mg/ml KCl, 8 mg/ml NaCl, G-banding was
completed by staining the slides with 2% Giemsa (Merck) in pH 6.8 phosphate
buffer for 4-5 min.(ABSTRACT TRUNCATED AT 250 WORDS) THE PURPOSE: The purpose of this research consisted in monitoring of brightness
temperature of the suspension of follicular thyroid carcinoma cells during the
necrosis of these cells in superhigh frequency (SHF) range.
METHODS: The monitoring of the change in the ratio between brightness
temperatures TSHF and TIR values during the necrosis of these cells. The object
of study was follicular thyroid carcinoma cells suspension prepared with use of
Versene solution and 0.25% trypsin solution. The cells were precipitated by
centrifugation and re-suspended in culture medium. The measurements of
brightness temperatures were carried out with use of radiothermoimeter. SHF
range was 3.4-4.2 GHz, and infrared (IR) range was 8-13 mm. The temperature of
the suspension was maintained at 37.5°С.
RESULTS: It was found that upon the necrosis in the suspension of cells, an
increase in brightness temperature in 3.4-4.2 GHz range (SHF range) occurs,
while brightness temperature of the medium in the IR range does not change.
CONCLUSION: The monitoring of necrosis of follicular thyroid carcinoma cells was
carried out by SHF-radiothermometry. It was shown that during the necrosis the
change of non-equilibrium state of cell medium occurs, that results in the
change in the ratio between TSHF and TIR. During the necrosis, the brightness
temperature in SHF range (TSHF) increases. |
Are circRNAs susceptible to degradation by RNase R? | Currently, an increasing body of evidence has demonstrated that 1) majority of circRNAs are evolutionarily conserved across species, stable, and resistant to RNase R degradation. | In platelets, splicing and translation occur in the absence of a nucleus.
However, the integrity and stability of mRNAs derived from megakaryocyte
progenitor cells remain poorly quantified on a transcriptome-wide level. As
circular RNAs (circRNAs) are resistant to degradation by exonucleases, their
abundance relative to linear RNAs can be used as a surrogate marker for mRNA
stability in the absence of transcription. Here we show that circRNAs are
enriched in human platelets 17- to 188-fold relative to nucleated tissues and
14- to 26-fold relative to samples digested with RNAse R to selectively remove
linear RNA. We compare RNAseq read depths inside and outside circRNAs to provide
in silico evidence of transcript circularity, show that exons within circRNAs
are enriched on average 12.7 times in platelets relative to nucleated tissues
and identify 3162 genes significantly enriched for circRNAs, including some
where all RNAseq reads appear to be derived from circular molecules. We also
confirm that this is a feature of other anucleate cells through transcriptome
sequencing of mature erythrocytes, demonstrate that circRNAs are not enriched in
cultured megakaryocytes, and demonstrate that linear RNAs decay more rapidly
than circRNAs in platelet preparations. Collectively, these results suggest that
circulating platelets have lost >90% of their progenitor mRNAs and that
translation in platelets occurs against the backdrop of a highly degraded
transcriptome. Finally, we find that transcripts previously classified as
products of reverse transcriptase template switching are both enriched in
platelets and resistant to decay, countering the recent suggestion that up to
50% of rearranged RNAs are artifacts. Our understanding of the highly specialized functions for small non-coding
single-stranded RNA (ssRNA) in the transcriptome of the human central nervous
system (CNS) continues to evolve. Circular RNAs (circRNAs), a recently
discovered class of ssRNA enriched in the brain and retina, are extremely stable
and intrinsically resilient to degradation by exonuclease. Conventional methods
of ssRNA, microRNA (miRNA), or messenger RNA (mRNA) detection and quantitation
requiring free ribonucleotide ends may have considerably underestimated the
quantity and significance of CNS circRNA in the CNS. Highly-specific small
ssRNAs, such as the ~23 nucleotide (nt) Homo sapien microRNA-7 (hsa-miRNA-7; chr
9q21.32), are not only abundant in the human limbic system but are, in addition,
associated with a ~1400 nt circRNA for miRNA-7 (ciRS-7) in the same anatomical
region. Structurally, ciRS-7 contains about ~70 tandem anti-miRNA-7 sequences
and acts as an endogenous, anti-complementary miRNA-7 "sponge" that attracts,
binds, and, hence, quenches, natural miRNA-7 functions. Using a combination of
DNA and miRNA array technologies, enhanced LED-Northern and Western blot
hybridization, and the magnesium-dependent exoribonuclease and circRNA-sensitive
probe RNaseR, here we provide evidence of a significantly misregulated
ciRS-7-miRNA-7-UBE2A circuit in sporadic Alzheimer's disease (AD) neocortex
(Brodmann A22) and hippocampal CA1. Deficits in ciRS-7-mediated "sponging
events", resulting in excess ambient miRNA-7 appear to drive the selective
down-regulation in the expression of miRNA-7-sensitive mRNA targets, such as
that encoding the ubiquitin conjugating enzyme E2A (UBE2A; chr Xq24). UBE2A,
which normally serves as a central effector in the ubiquitin-26S proteasome
system, coordinates the clearance of amyloid peptides via proteolysis, is known
to be depleted in sporadic AD brain and, hence, contributes to amyloid
accumulation and the formation of senile plaque deposits. Dysfunction of
circRNA-miRNA-mRNA regulatory systems appears to represent another important
layer of epigenetic control over pathogenic gene expression programs in the
human CNS that are targeted by the sporadic AD process. Circular RNAs (circRNAs) own unique capabilities to communicate with nucleic
acids and ribonucleoproteins and are emerging as indispensable compositions of
the regulatory messages encoded in the genome. Due to lack of 3' termini,
circRNAs are more resistant to degradation by exonuclease RNase R and possess
greater stability than linear RNAs. Moreover, circRNAs can act as microRNA
(miRNA) sponge and affect messenger RNA (mRNA) splicing and transcription. By
virtue of their great stability and elaborate regulatory mechanisms of gene
expression, circRNAs play important roles in certain physiological activities.
The development, homeostasis and stress response of the central nervous system
(CNS) depend upon precise temporal and spatial regulation of gene networks.
Moreover, emerging evidence has revealed that circRNAs are spatiotemporally
regulated and dynamically expressed during brain development; therefore, they
can exert significant influences on CNS development and diseases. In this
review, we highlight the biogenesis of circRNAs and their central roles in
regulation of CNS development and diseases. Circular RNAs (circRNAs) are a class of animal non-coding RNAs and play an
impor-tant role in animal growth and development. However, the expression and
function of circRNAs in the pituitary gland of sheep are unclear. Transcriptome
profiling of circRNAs in the pituitary gland of sheep may enable us to
understand their biological functions. In the present study, we identified
10,226 circRNAs from RNA-seq data in the pituitary gland of prenatal and
postnatal sheep. Reverse transcription PCR and DNA sequencing analysis confirmed
the presence of several circRNAs. Real-time RT-PCR analysis showed that sheep
circRNAs are resistant to RNase R digestion and are expressed in prenatal and
postnatal pituitary glands. GO and KEGG enrichment analysis showed that host
genes of differentially expressed circRNAs are involved in the regulation of
hormone secretion as well as in several pathways related to these processes. We
determined that numerous circRNAs interact with pituitary-specific miRNAs that
are involved in the biologic functions of the pituitary gland. Moreover, several
circRNAs contain at least one IRES element and open reading frame, indicating
their potential to encode proteins. Our study provides comprehensive expression
profiles of circRNAs in the pituitary gland, thereby offering a valuable
resource for circRNA biology in sheep. MicroRNAs (miRs) are post-transcriptional regulators involved in the initiation
and progression of many tumors. Recently, naturally occurring circular RNAs
(circRNAs) have been described in eukaryotic cells:;they comprise a new class of
gene regulators. Naturally occurring circular miR sponges, which induce miR
loss-of-function, can prevent endogenous onco-miRs from binding to their cognate
mRNA targets. These findings suggest that synthetic (artificial) circular RNAs
could be constructed as therapeutic molecular sponges to suppress harmful
onco-miRs. Using enzymatic ligation, we designed and constructed a circular RNA
containing both miR-21 and miR-93 binding sites. The synthetic circular sponge
was resistant to digestion with RNase R. Luciferase assays and functional
experiments showed that the circular multi-miR sponge was more stable than its
linear counterpart. Moreover, endogenous miR-21 and miR-93 were inhibited by the
circular sponge. In addition, the synthetic sponge significantly suppressed
cellular proliferation and migration while promoting apoptosis in esophageal
carcinoma cells. Finally, in a murine xenograft model, the circular sponge
significantly inhibited tumor growth in vivo. Taken together, these findings
establish that the design and construction of efficient artificial miR sponges
represent a novel strategy to achieve miR loss-of-function in molecular cancer
therapeutics. Thousands of eukaryotic protein-coding genes generate circular RNAs that have
covalently linked ends and are resistant to degradation by exonucleases. To
prove their circularity as well as biochemically enrich these transcripts, it
has become standard in the field to use the 3'-5' exonuclease RNase R. Here, we
demonstrate that standard protocols involving RNase R can fail to digest >20% of
all highly expressed linear RNAs, but these shortcomings can largely be
overcome. RNAs with highly structured 3' ends, including snRNAs and histone
mRNAs, are naturally resistant to RNase R, but can be efficiently degraded once
a poly(A) tail has been added to their ends. In addition, RNase R stalls in the
body of many polyadenylated mRNAs, especially at G-rich sequences that have been
previously annotated as G-quadruplex (G4) structures. Upon replacing K+ (which
stabilizes G4s) with Li+ in the reaction buffer, we find that RNase R is now
able to proceed through these sequences and fully degrade the mRNAs in their
entirety. In total, our results provide important improvements to the current
methods used to isolate circular RNAs as well as a way to reveal RNA structures
that may naturally inhibit degradation by cellular exonucleases. Circular RNAs (circRNAs) are a class of endogenous noncoding RNAs that have been
shown to play a role in normal development, homeostasis, and disease, including
cancer. CircRNAs are formed through a process called back-splicing, which
results in a covalently closed loop with a nonlinear back-spliced junction
(BSJ). In general, circRNA BSJs are predicted in RNA sequencing data using one
of numerous circRNA detection algorithms. Selected circRNAs are then typically
validated using an orthogonal method such as reverse transcription quantitative
PCR (RT-qPCR) with circRNA-specific primers. However, linear transcripts
originating from endogenous trans-splicing can lead to false-positive signals
both in RNA sequencing and in RT-qPCR experiments. Therefore, it is essential to
perform the RT-qPCR validation step only after linear RNAs have been degraded
using an exonuclease such as ribonuclease R (RNase R). Several RNase R protocols
are available for circRNA detection using RNA sequencing or RT-qPCR. These
protocols-which vary in enzyme concentration, RNA input amount, incubation
times, and cleanup steps-typically lack a detailed validated standard protocol
and fail to provide a range of conditions that deliver accurate results. As
such, some protocols use RNase R concentrations that are too high, resulting in
partial degradation of the target circRNAs. Here, we describe an optimized
workflow for circRNA validation, combining RNase R treatment and RT-qPCR. First,
we outline the steps for circRNA primer design and qPCR assay validation. Then,
we describe RNase R treatment of total RNA and, importantly, a subsequent
essential buffer cleanup step. Lastly, we outline the steps to perform the
RT-qPCR and discuss the downstream data analyses. © 2021 Wiley Periodicals LLC.
Basic Protocol 1: CircRNA primer design and qPCR assay validation Basic Protocol
2: RNase R treatment, cleanup, and RT-qPCR. Circular RNA(circRNA)is a novel type of endogenous non-coding RNA.Most circRNAs
act as microRNA(miRNA)sponges to regulate the expression of functional genes.In
addition,some circRNAs can be translated and interact with RNA-binding proteins
to perform biological functions.The expression of circRNAs is prevalent in
tissues and body fluids,and their abnormal expression is related to tumor
progression.circRNAs are stable even under the treatment of RNase R because of
their circular conformation.As circRNAs have construct stability,wide
variety,specific regulation of tumor progression and high expression in body
fluids,it is potential for circRNAs to serve as candidate diagnostic,prognostic
and therapeutic targets.However,the knowledge about circRNAs remains poor.In
addition to the not completely resolved functions and generation mechanisms of
circRNAs,the annotations of circRNAs are also waiting for expanding.Here,we
review the generation mechanisms,biological functions,and application of
circRNAs in tumor research,aiming to provide integrated information for the
future research. Circular RNA (circRNA) has a closed-loop structure, and its 3' and 5' ends are
directly covalently connected by reverse splicing, which is more stable than
linear RNA. CircRNAs usually possess microRNA (miRNA) binding sites, which can
bind miRNAs and inhibit miRNA function. Many studies have shown that circRNAs
are involved in the processes of cell senescence, proliferation and apoptosis
and a series of signalling pathways, playing an important role in the prevention
and treatment of diseases. CircRNAs are potential biological diagnostic markers
and therapeutic targets for cardiovascular diseases (CVDs). To identify
biomarkers and potential effective therapeutic targets without toxicity for
heart disease, we summarize the biogenesis, biology, characterization and
functions of circRNAs in CVDs, hoping that this information will shed new light
on the prevention and treatment of CVDs. |
Does atemoya juice inhibit tye CYP3A4 enzyme? | No, atemoya juice does not inhibit CYP3A4. | BACKGROUND AND OBJECTIVES: Atemoya (Annona atemoya) is increasingly being
consumed worldwide because of its pleasant taste. However, only limited
information is available concerning possible atemoya-drug interactions. In the
present study, the issue of whether atemoya shows food-drug interactions with
substrate drugs of the major drug-metabolizing cytochrome P450s (i.e., CYP1A2,
CYP2C9, and CYP3A) is addressed.
METHODS: The ability of atemoya juice to inhibit the activities of phenacetin
O-deethylase (CYP1A2), diclofenac 4'-hydroxylase (CYP2C9), and midazolam
1'-hydroxylase (CYP3A) was examined in vitro using human and rat liver
microsomes. The in vivo pharmacokinetics of phenacetin and metabolites derived
from it in rats when atemoya juice or fluvoxamine (a CYP1A2 inhibitor) was
preadministered were also investigated.
RESULTS: Atemoya juice significantly inhibited CYP1A2 activity in human liver
microsomes, but not the activities of CYP2C9 and CYP3A. In spite of this
inhibition, preadministration of atemoya had no effect on the pharmacokinetics
of phenacetin, a CYP1A2 substrate, in rats. Meanwhile, preadministration of
fluvoxamine significantly extended the time needed for the elimination of
phenacetin, possibly due to the inhibition of CYP1A2. This suggests that the
intake of an excess amount of atemoya juice is necessary to cause a change in
the pharmacokinetics of phenacetin when the IC50 values for CYP1A2 inhibition by
atemoya and fluvoxamine are taken into account.
CONCLUSION: The results indicate that a daily intake of atemoya would not change
the pharmacokinetics of CYP1A2 substrates such as phenacetin as well as CYP2C9-
and CYP3A-substrate drugs. |
Which processes are affected by pathogenic SPTBN1 variants? | SPTBN1 variants lead to effects that affect βII-spectrin stability, disrupt binding to key molecular partners, and disturb cytoskeleton organization and dynamics. | Author information:
(1)Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA.
[email protected].
(2)Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, USA.
[email protected].
(3)Department of Cell Biology and Physiology, University of North Carolina at
Chapel Hill, Chapel Hill, NC, USA.
(4)Department of Pediatrics, Duke University Medical Center, Duke University,
Durham, NC, USA.
(5)GeneDx, Gaithersburg, MD, USA.
(6)Bioinformatics Research and Development Laboratory, Genomic Sciences and
Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, USA.
(7)Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel
Hill, NC, USA.
(8)Carolina Institute for Developmental Disabilities, University of North
Carolina at Chapel Hill, Chapel Hill, NC, USA.
(9)Neuroscience Center, University of North Carolina at Chapel Hill, Chapel
Hill, NC, USA.
(10)Human Pluripotent Stem Cell Core, University of North Carolina at Chapel
Hill, Chapel Hill, NC, USA.
(11)Department of Pathology, Yale University, New Haven, CT, USA.
(12)Department of Neurology, Columbia University, New York, NY, USA.
(13)Institute for Genomic Medicine, Columbia University, New York, NY, USA.
(14)Laboratory of Personalized Genomic Medicine, Department of Pathology and
Cell Biology, Columbia University, New York, NY, USA.
(15)Department of Clinical Genetics, Erasmus MC University Medical Center,
Rotterdam, the Netherlands.
(16)Institute of Human Genetics, University of Bonn, School of Medicine &
University Hospital Bonn, Bonn, Germany.
(17)McMaster University, Hamilton, Ontario, Canada.
(18)Department of Genetics, University Medical Center Utrecht, Utrecht, the
Netherlands.
(19)Spectrum Health Medical Genetics, Grand Rapids, MI, USA.
(20)Division of Neurology, Departments of Neurology and Pediatrics, The
Children's Hospital of Philadelphia and the Perelman School of Medicine at the
University of Pennsylvania, Philadelphia, PA, USA.
(21)The Epilepsy NeuroGenetics Initiative, Children's Hospital of Philadelphia,
Philadelphia, PA, USA.
(22)Department of Biomedical and Health Informatics (DBHi), Children's Hospital
of Philadelphia, Philadelphia, PA, USA.
(23)Department of Neurology, University of Pennsylvania, Perelman School of
Medicine, Philadelphia, PA, USA.
(24)Genetics, Driscoll Children's Hospital, Corpus Christi, TX, USA.
(25)Service de Génétique Médicale, CHU Nantes, Nantes, France.
(26)Université de Nantes, CNRS, INSERM, L'Institut du Thorax, Nantes, France.
(27)William Harvey Research Institute, School of Medicine and Dentistry, Queen
Mary University of London, London, UK.
(28)Department of Clinical Genetics, Cambridge University Hospitals, Cambridge,
UK.
(29)Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK.
(30)Institute of Human Genetics, University Medical Center Hamburg-Eppendorf,
Hamburg, Germany.
(31)Neuropediatrics, Department of Pediatrics, University Medical Center
Hamburg-Eppendorf, Hamburg, Germany.
(32)Division of Medical Genetics, Department of Pediatrics, University of
California San Francisco, San Francisco, CA, USA.
(33)Institute for Human Genetics, University of California San Francisco, San
Francisco, CA, USA.
(34)Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA,
USA.
(35)Nicklaus Children's Hospital, Miami, FL, USA.
(36)Department of Psychiatry and Behavioral Sciences, University of Washington,
Seattle, WA, USA.
(37)Department of Genome Sciences, University of Washington School of Medicine,
Seattle, WA, USA.
(38)Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA.
(39)Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA.
(40)Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.
(41)Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, USA.
(42)Divisions of Clinical/Metabolic Genetics and Neurology, The Hospital for
Sick Children, University of Toronto, Toronto, Ontario, Canada.
(43)Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany.
(44)Institute of Human Genetics, Technical University of Munich, Munich,
Germany.
(45)Department of Neurology, Charles University, 1st Faculty of Medicine and
General University Hospital in Prague, Prague, Czech Republic.
(46)Lehrstuhl für Neurogenetik, Technische Universität München, Munich, Germany.
(47)Munich Cluster for Systems Neurology, SyNergy, Munich, Germany.
(48)Department of Genetics, University of North Carolina at Chapel Hill, Chapel
Hill, NC, USA.
(49)Department of Pharmacology, University of North Carolina at Chapel Hill,
Chapel Hill, NC, USA.
(50)Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI,
USA.
(51)Clinical and Translational Sciences Institute, Medical College of Wisconsin,
Milwaukee, WI, USA.
(52)Department of Biochemistry and Biophysics, University of North Carolina at
Chapel Hill, Chapel Hill, NC, USA.
(53)Department of Cell Biology and Physiology, University of North Carolina at
Chapel Hill, Chapel Hill, NC, USA. [email protected].
(54)Carolina Institute for Developmental Disabilities, University of North
Carolina at Chapel Hill, Chapel Hill, NC, USA. [email protected].
(55)Neuroscience Center, University of North Carolina at Chapel Hill, Chapel
Hill, NC, USA. [email protected].
(#)Contributed equally |
Describe the role of bevacizumab in radiosurgery for arteriovenous malformation. | Bevacizumab is used for the treatment of severe, refractory perilesional edema due to an arteriovenous malformation treated with stereotactic radiosurgery. | The authors present a case of an arteriovenous malformation of the central
sulcus treated with Gamma Knife surgery. The patient developed perilesional
edema 9 months after treatment and experienced severe headache and hemiparesis.
Her symptoms were refractory to corticosteroid therapy and pain management. She
was subsequently treated with bevacizumab with striking improvement in her
symptoms and results of neuroimaging studies. This is the first time that
bevacizumab has been used to control severe refractory perilesional edema
related to an intracranial arteriovenous malformation. To retrospectively evaluate the clinical benefit and imaging response of
bevacizumab when used to treat refractory adverse radiation effects (ARE) after
stereotactic radiosurgery. Twenty-nine patients with brain tumors or vascular
malformations developed clinical and/or imaging evidence of ARE after SRS and
were treated using bevacizumab. Patients received an average dose of 7.4 mg/kg
over a mean of 5.7 weeks at a median of 16 months following SRS. Initial
diagnosis, SRS dose, bevacizumab treatment protocols, magnetic resoce imaging
T2/FLAIR and T1 paramagnetic contrast enhanced edema volumes were compared
before and after bevacizumab administration. Ninety percent (18/20) with
clinically symptomatic ARE had neurological improvement after bevacizumab
therapy. Twenty-six patients had a decrease of 62 % of T2/FLAIR volumes and a 50
% decrease in magnetic resoce imaging intravenous contrast enhancement
volumes. Two patients showed progression of the T2/FLAIR and contrast
enhancement volumes. One patient had progression of post-Gd-enhancement but
regression of T2/FLAIR volume. Symptoms recurred in 11 of the 20 patients after
discontinuing therapy. Patients who experienced a return of enhancement received
a lower marginal dose during SRS. Our experience provides additional evidence
that bevacizumab reduces both symptoms and reactive imaging changes in patients
with ARE. After SRS, refractory ARE unresponsive to initial corticosteroids or
other agents may benefit from a bevacizumab trial. The necessary duration and
optimum dose of therapy is unknown and provides a further impetus to conduct a
prospective trial. Radiation necrosis (RN) is a serious complication that can occur in up to 10% of
brain radiotherapy cases, with the incidence dependent on both dose and brain
location. Available medical treatment for RN includes steroids, vitamin E,
pentoxifylline, and hyperbaric oxygen. In a significant number of patients,
however, RN is medically refractory and the patients experience progressive
neurological decline, disabling headaches, and decreased quality of life.
Vascular endothelial growth factor (VEGF) is a known mediator of cerebral edema
in RN. Recent reports have shown successful treatment of RN with intravenous
bevacizumab, a monoclonal antibody for VEGF. Bevacizumab, however, is associated
with significant systemic complications including sinus thrombosis, pulmonary
embolus, gastrointestinal tract perforation, wound dehiscence, and severe
hypertension. Using lower drug doses may decrease systemic exposure and reduce
complication rates. By using an intraarterial route for drug administration
following blood-brain barrier disruption (BBBD), the authors aim to lower the
bevacizumab dose while increasing target delivery. In the present report, the
authors present the cases of 2 pediatric patients with cerebral arteriovenous
malformations, who presented with medically intractable RN following
stereotactic radiosurgery. They received a single intraarterial infusion of 2.5
mg/kg bevacizumab after hyperosmotic BBBD. At mean follow-up duration of 8.5
months, the patients had significant and durable clinical and radiographic
response. Both patients experienced resolution of their previously intractable
headaches and reversal of cushingoid features as they were successfully weaned
off steroids. One of the patients regained significant motor strength. There was
an associated greater than 70% reduction in cerebral edema. Intraarterial
administration of a single low dose of bevacizumab after BBBD was safe and
resulted in durable clinical and radiographic improvements at concentrations
well below those required for the typical systemic intravenous route. Advantages
over the intravenous route may include higher concentration of drug delivery to
the affected brain, decreased systemic toxicity, and a significantly lower cost. Stereotactic radiosurgery has long been recognized as the optimal form of
management for high-grade arteriovenous malformations not amenable to surgical
resection. Radiosurgical plans have generally relied upon the integration of
stereotactic magnetic resoce angiography (MRA), standard contrast-enhanced
magnetic resoce imaging (MRI), or computed tomography angiography (CTA) with
biplane digital subtraction angiography (DSA). Current options are
disadvantageous in that catheter-based biplane DSA is an invasive test
associated with a small risk of complications and perhaps more importantly, the
two-dimensional nature of DSA is an inherent limitation in creating
radiosurgical contours. The necessity of multiple scans to create DSA contours
for radiosurgical planning puts patients at increased risk. Furthermore, the
inability to import two-dimensional plans into some radiosurgery programs, such
as Cyberknife TPS, limits treatment options for patients. Defining the nidus
itself is sometimes difficult in any of the traditional modalities as all
draining veins and feeding arteries are included in the images. This sometimes
necessitates targeting a larger volume, than strictly necessary, with
stereotactic radiosurgery for treatment of the AVM. In this case report, we show
the ability to use a less-invasive and three-dimensional form of angiography
based on time-lapsed CTA (4D-CTA) rather than traditional DSA for radiosurgical
planning. 4D-CTA may allow generation of a series of images, which can show the
flow of contrast through the AVM. A review of these series may allow the surgeon
to pick and use a volume set that best outlines the nidus with least
interference from feeding arteries or draining veins. In addition, 4D-CTA scans
can be uploaded into radiosurgery programs and allow three-dimensional
targeting. This is the first reported case demonstrating the use of a 4D CTA and
an MRI to delineate the AVM nidus for Gamma Knife radiosurgery, with complete
obliteration of the nidus over time and subsequent management of associated
radiation necrosis with bevacizumab. |
Is Mycobacterium abscessus a human pathogen? | Yes,
Mycobacterium abscessus is unique in terms of its high morbidity and treatment failure rates. | Improvements in the exit-site care for peritoneal dialysis (PD) patients have
uncovered a trend for increasing incidence of rapidly growing nontuberculous
mycobacterium exit-site infections (ESI). Among these, Mycobacterium abscessus
is unique in terms of its high morbidity and treatment failure rates. The
international society of PD guidelines encourage PD catheter removal in patients
with M. abscessus peritonitis but, do not have evidence-based recommendations
for the management of ESIs related to this organism. We report an unusual case
in which an asymptomatic end-stage renal disease patient with multiple favorable
clinical characteristics, i.e., no apparent immunodeficiency, sensitivity
pattern showing possibility of treatment with multiple antibiotics, no evidence
of peritonitis, and early clinical response, was treated with a 9-month
combination antimicrobial regimen administered orally and intraperitoneally.
Despite excellent clinical response with a resolution of the ESI, our patient
relapsed quickly, within 30 days of stopping antimicrobial therapy and required
PD catheter removal. Our case, taken together with available published case
reports, highlights the futility of the conservative approach towards the M.
abscessus ESI and makes the cases for early PD catheter removal in these
patients. Mycobacterium abscessus lung disease is difficult to treat due to intrinsic drug
resistance and the persistence of drug-tolerant bacteria. Currently, the
standard of care is a multidrug regimen with at least 3 active drugs, preferably
including a β-lactam (imipenem or cefoxitin). These regimens are lengthy and
toxic and have limited efficacy. The search for more efficacious regimens led us
to evaluate bedaquiline, a diarylquinoline licensed for treatment of
multidrug-resistant tuberculosis. We performed in vitro time-kill experiments to
evaluate the activity of bedaquiline alone and in combination with the
first-line drug imipenem against M. abscessus under various conditions. Against
actively growing bacteria, bedaquiline was largely bacteriostatic and
antagonized the bactericidal activity of imipenem. Contrarily, against
nutrient-starved persisters, bedaquiline was bactericidal, while imipenem was
not, and bedaquiline drove the activity of the combination. In an intracellular
infection model, bedaquiline and imipenem had additive bactericidal effects.
Correlations between ATP levels and the bactericidal activity of imipenem and
its antagonism by bedaquiline were observed. Interestingly, the presence of
Tween 80 in the media affected the activity of both drugs, enhancing the
activity of imipenem and reducing that of bedaquiline. Overall, these results
show that bedaquiline and imipenem interact differently depending on culture
conditions. Previously reported antagonistic effects of bedaquiline on imipenem
were limited to conditions with actively multiplying bacteria and/or the
presence of Tween 80, whereas the combination was additive or indifferent
against nutrient-starved and intracellular M. abscessus, where promising
bactericidal activity of the combination suggests it may have a role in future
treatment regimens. Mycobacterium abscessus has been recognised as a dreadful respiratory pathogen
among the non-tuberculous mycobacteria (NTM) because of misdiagnosis, prolonged
therapy with poor treatment outcomes and a high cost. This pathogen also shows
extremely high antimicrobial resistance against current antibiotics, including
the anti-tuberculosis agents. Therefore, current chemotherapies require a long
curative period and the clinical outcomes are not satisfactory. Thus, there is
an urgent need for discovering and developing novel, more effective anti-M.
abscessus drugs. In this review, we sum the effectiveness of the current anti-M.
abscessus drugs and drug candidates. Furthermore, we describe the shortcomings
and difficulties associated with M. abscessus drug discovery and development. |
What is the indication for Favipiravir? | Favipiravir (FVP) has been used for treatment of COVID-19 in many countries. | BACKGROUND: Lassa and Junín viruses are the most prominent members of the
Arenaviridae family of viruses that cause viral hemorrhagic fever syndromes
Lassa fever and Argentine hemorrhagic fever, respectively. At present, ribavirin
is the only antiviral drug indicated for use in treatment of these diseases, but
because of its limited efficacy in advanced cases of disease and its toxicity,
safer and more effective antivirals are needed.
METHODOLOGY/PRINCIPAL FINDINGS: Here, we used a model of acute arenaviral
infection in outbred guinea pigs based on challenge with an adapted strain of
Pichindé virus (PICV) to further preclinical development of T-705 (Favipiravir),
a promising broad-spectrum inhibitor of RNA virus infections. The guinea
pig-adapted passage 19 PICV was uniformly lethal with an LD(50) of ∼5
plaque-forming units and disease was associated with fever, weight loss,
thrombocytopenia, coagulation defects, increases in serum aspartate
aminotransferase (AST) concentrations, and pantropic viral infection.
Favipiravir (300 mg/kg/day, twice daily orally for 14 days) was highly
effective, as all animals recovered fully from PICV-induced disease even when
therapy was initiated one week after virus challenge when animals were already
significantly ill with marked fevers and thrombocytopenia. Antiviral activity
and reduced disease severity was evidenced by dramatic reductions in peak serum
virus titers and AST concentrations in favipiravir-treated animals. Moreover, a
sharp decrease in body temperature was observed shortly after the start of
treatment. Oral ribavirin was also evaluated, and although effective, the slower
rate of recovery may be a sign of the drug's known toxicity.
CONCLUSIONS/SIGNIFICANCE: Our findings support further development of
favipiravir for the treatment of severe arenaviral infections. The optimization
of the experimental favipiravir treatment regimen in the PICV guinea pig model
will inform critical future studies in the same species based on challenge with
highly pathogenic arenaviruses such as Lassa and Junín. Favipiravir, an influenza virus RNA polymerase inhibitor, and peramivir, an
influenza virus neuraminidase inhibitor, were evaluated alone and in combination
against pandemic influenza A/California/04/2009 (H1N1) virus infections in mice.
Infected mice were treated twice daily for 5 d starting 4 h after virus
challenge. Favipiravir was 40%, 70%, and 100% protective at 20, 40, and 100
mg/kg/d. Peramivir was 30% protective at 0.5 mg/kg/d, but ineffective at lower
doses when used as monotherapy. Combinations of favipiravir and peramivir
increased the numbers of survivors by 10-50% when the 0.025, 0.05, and 0.1
mg/kg/d doses of peramivir were combined with 20 mg/kg/d favipiravir and when
all doses of peramivir were combined with 40 mg/kg/d favipiravir.
Three-dimensional analysis of drug interactions using the MacSynergy method
indicates strong synergy for these drug combinations. In addition, an increase
in lifespan for groups of mice treated with drug combinations, compared to the
most effective monotherapy group, was observed for the 0.025, 0.05, and 0.1
mg/kg/d doses of peramivir combined with favipiravir at the 20 mg dose level.
Therefore, the 20 mg/kg/d dose of favipiravir was selected for further
combination studies. Increased survival was exhibited when this dose was
combined with peramivir doses of 0.1, 0.25 and 0.5 mg/kg/d (1 mg/kg/d of
peramivir alone was 100% protective in this experiment). Improved body weight
relative to either compound alone was evident using 0.25, 0.5, and 1 mg/kg/d of
peramivir. Significant reductions in lung hemorrhage score and lung weight were
evident on day 6 post-infection. In addition, virus titers were reduced
significantly on day 4 post-infection by combination therapy containing
favipiravir combined with peramivir at 0.25 and 0.5 mg/kg/d. These data
demonstrate that combinations of favipiravir and peramivir perform better than
suboptimal doses of each compound alone for the treatment of influenza virus
infections in mice. Human noroviruses are the primary cause of foodborne gastroenteritis. Potent and
safe inhibitors are needed for the treatment/prophylaxis of norovirus
infections. We demonstrate that Favipiravir [T-705, a drug in advanced clinical
development for the treatment of infections with the influenza virus] inhibits
in vitro murine norovirus replication. Time-of-drug addition studies reveal that
T-705 exerts its activity at a time-point that coincides with onset of viral RNA
synthesis, which is in line with the viral polymerase as the presumed target. AIM: Favipiravir and oseltamivir are antiviral compounds used for the treatment
of influenza infections. We have aimed to investigate the efficacy of the
compounds in combination to treat influenza H1N1 virus infections in mice.
MATERIALS & METHODS: Mice infected with pandemic influenza A/California/04/2009
(H1N1pdm) virus or an oseltamivir-resistant (H275Y neuraminidase mutation)
influenza A/Mississippi/ 3/2001 (H1N1) virus were treated orally with inhibitors
twice a day for 5 days starting 4 h after infection.
RESULTS: Complete protection from death was afforded by favipiravir treatments
of 100 mg/kg/day, but lower doses were less effective. Combinations of
oseltamivir (1 and 3 mg/kg/day) with favipiravir (3, 10 and 30 mg/kg/day)
resulted in a synergistic improvement in survival rates against H1N1pdm
infections. Significant reductions in lung virus titers also occurred. Against
the H275Y virus infection, oseltamivir alone was only 30% protective from death
at 100 mg/kg/day, but combinations of the two compounds produced a synergistic
improvement in survival rate.
CONCLUSION: The utility of treating H1N1 influenza virus infections with
oseltamivir and favipiravir in combination has been established. Author information:
(1)Department of Medicinal Chemisry, Key Laboratory of Chemical Biology
(Ministry of Education), School of Pharmaceutical Sciences, Shandong University,
Ji 255012, China; Shandong Qidu Pharmaceutical Co. Ltd., Shandong Provincial
Key Laboratory of Neuroprotective Drugs, Zibo 255400, China.
(2)Shandong Qidu Pharmaceutical Co. Ltd., Shandong Provincial Key Laboratory of
Neuroprotective Drugs, Zibo 255400, China.
(3)Department of Medicinal Chemisry, Key Laboratory of Chemical Biology
(Ministry of Education), School of Pharmaceutical Sciences, Shandong University,
Ji 255012, China.
(4)Department of Medicinal Chemisry, Key Laboratory of Chemical Biology
(Ministry of Education), School of Pharmaceutical Sciences, Shandong University,
Ji 255012, China. Electronic address: [email protected]. Favipiravir (T-705; 6-fluoro-3-hydroxy-2-pyrazinecarboxamide) is an anti-viral
agent that selectively and potently inhibits the RNA-dependent RNA polymerase
(RdRp) of RNA viruses. Favipiravir was discovered through screening chemical
library for anti-viral activity against the influenza virus by Toyama Chemical
Co., Ltd. Favipiravir undergoes an intracellular phosphoribosylation to be an
active form, favipiravir-RTP (favipiravir ribofuranosyl-5'-triphosphate), which
is recognized as a substrate by RdRp, and inhibits the RNA polymerase activity.
Since the catalytic domain of RdRp is conserved among various types of RNA
viruses, this mechanism of action underpins a broader spectrum of anti-viral
activities of favipiravir. Favipiravir is effective against a wide range of
types and subtypes of influenza viruses, including strains resistant to existing
anti-influenza drugs. Of note is that favipiravir shows anti-viral activities
against other RNA viruses such as arenaviruses, bunyaviruses and filoviruses,
all of which are known to cause fatal hemorrhagic fever. These unique anti-viral
profiles will make favipiravir a potentially promising drug for specifically
untreatable RNA viral infections. Favipiravir, also known as T-705, is an antiviral drug that has been approved in
2014 in Japan to treat pandemic influenza virus infections. The drug is
converted intracellularly into its active, phosphoribosylated form, which is
recognized as a substrate by the viral RNA-dependent RNA polymerase.
Interestingly, besides its anti-influenza virus activity, this molecule is also
able to inhibit the replication of flavi-, alpha-, filo-, bunya-, arena-, noro-,
and of other RNA viruses, which include neglected and (re)emerging viruses for
which no antiviral therapy is currently available. We will discuss the potential
of favipiravir as a broad-spectrum countermeasure against infections caused by
such neglected RNA viruses. Favipiravir has already been used off-label to treat
patients infected with the Ebola virus and the Lassa virus. Because of the
particular set-up of the clinical trials during these outbreaks, clear
conclusions on the efficacy of favipiravir could not be made. For several
viruses, it was demonstrated that the barrier of resistance development against
favipiravir is high. Favipiravir has been shown to be well tolerated in healthy
volunteers and in influenza virus-infected patients; however, caution is needed
because of the teratogenic risks of this molecule. Because of its antiviral
activity against different RNA viruses and its high barrier for resistance, the
potential of favipiravir as a broad-spectrum antiviral seems promising, but
safety and potency issues should be overcome before this drug or similar
molecules could be used to treat large patient groups. Nipah and Hendra viruses are recently emerged bat-borne paramyxoviruses (genus
Henipavirus) causing severe encephalitis and respiratory disease in humans with
fatality rates ranging from 40-75%. Despite the severe pathogenicity of these
viruses and their pandemic potential, no therapeutics or vaccines are currently
approved for use in humans. Favipiravir (T-705) is a purine analogue antiviral
approved for use in Japan against emerging influenza strains; and several phase
2 and 3 clinical trials are ongoing in the United States and Europe. Favipiravir
has demonstrated efficacy against a broad spectrum of RNA viruses, including
members of the Paramyxoviridae, Filoviridae, Arenaviridae families, and the
Bunyavirales order. We now demonstrate that favipiravir has potent antiviral
activity against henipaviruses. In vitro, favipiravir inhibited Nipah and Hendra
virus replication and transcription at micromolar concentrations. In the Syrian
hamster model, either twice daily oral or once daily subcutaneous administration
of favipiravir for 14 days fully protected animals challenged with a lethal dose
of Nipah virus. This first successful treatment of henipavirus infection in vivo
with a small molecule drug suggests that favipiravir should be further evaluated
as an antiviral treatment option for henipavirus infections. BACKGROUND: Repurposing broad-spectrum antivirals is an immediate treatment
opportunity for 2019 coronavirus disease (COVID-19). Favipiravir is an antiviral
previously indicated for influenza and Ebola, which has shown some promise in
early trials for treatment of COVID-19. We aim to review existing favipiravir
safety evidence, which is vital to informing the potential future use of
favipiravir in COVID-19.
METHODS: A search was conducted across EMBASE and MEDLINE databases,
supplemented by relevant grey-literature and ClinicalTrials.gov. All studies
assessing the use of favipiravir in humans by 27 March 2020 were considered for
inclusion. Further analysis of available safety data from phase 2 and 3 studies
was undertaken. Data extracted were adverse events (AEs) grade 1-4, serious AEs
and discontinuation for AEs. Specific AEs of interest highlighted in early-phase
studies, including gastrointestinal AEs and hyperuricaemia, were also examined.
RESULTS: Twenty-nine studies were identified as potential sources of evidence of
the clinical safety of favipiravir. Six were phase 2 and 3 studies reporting
relevant safety data for statistical comparison, representing a total of 4299
participants, an estimated 175 person-years-of-follow-up (PYFU). Comparator
drugs were oseltamivir, umifenovir, lopinavir/ritonavir or placebo. Study
follow-up was between 5 and 21 days. The proportions of grade 1-4 AEs on
favipiravir was 28.2% vs 28.4% (P = n.s.) in the comparison arms. The proportion
of discontinuations due to AEs on favipiravir was 1.1% vs 1.2% (P = n.s.) in the
comparison arms. For serious AEs the proportion was 0.4% in both arms
(P = n.s.). There were significantly fewer gastrointestinal AEs occurring on
favipiravir vs comparators [8.7% vs 11.5%; P = 0.003]. Favipiravir showed
significantly more uric acid elevations than comparators [5.8% vs 1.3%;
P<0.0001].
CONCLUSIONS: Favipiravir demonstrates a favourable safety profile regarding
total and serious AEs. However, safety concerns remain: hyperuricaemia,
teratogenicity and QTc prolongation have not yet been adequately studied.
Favipiravir may be safe and tolerable in short-term use, but more evidence is
needed to assess the longer-term effects of treatment. Given the limitations of
the evidence and unresolved safety concerns, caution is warranted in the
widespread use of favipiravir against pandemic COVID-19. Crimean-Congo hemorrhagic fever virus (CCHFV) is a widely distributed
hemorrhagic fever virus found throughout Eastern Europe, Africa, the Middle East
and Asia. It is spread through bites from infected ticks, animal husbandry and
can also be acquired in the healthcare setting during care of infected patients.
In humans, CCHFV can cause a sudden onset of a non-specific febrile illness that
can rapidly progress to severe hemorrhagic manifestations. Currently, there is
no widely available vaccine and although ribavirin has been suggested for the
treatment of CCHFV, clinical efficacy in both animal models and humans is
inconsistent suggesting more potent antivirals are needed for CCHFV. Favipiravir
is approved in Japan for the treatment of influenza virus infections and has
shown promise against other highly pathogenic RNA viruses including CCHFV with
demonstrated efficacy in the type I interferon deficient mouse model. In this
report we utilized the cynomolgus macaque model to evaluate the efficacy of
once- and twice-daily favipiravir treatment against CCHFV infection. We found
that favipiravir treatment suppressed viremia and viral shedding when treatment
was initiated 24 h post-infection and viral burdens in key tissues trended lower
in favipiravir-treated animals. Our data indicate that favipiravir has efficacy
against CCHFV in vivo in a non-human primate model of infection. Author information:
(1)Respiratory Medicine Komatsu Municipal Hospital Komatsu city Japan.
(2)Cellular Transplantation Biology Kanazawa University Graduate School of
Medical Science Kanazawa city Japan.
(3)Cardiovascular medicine Komatsu Municipal Hospital Komatsu city Japan.
(4)Respiratory Medicine Kanazawa University Hospital Kanazawa city Japan. We herein report the first case of a fever induced by favipiravir, a potential
coronavirus disease 2019 therapeutic drug. An 82-year-old man diagnosed with
bilateral pneumonia was transferred to our hospital following a positive severe
acute respiratory syndrome coronavirus 2 polymerase chain reaction test. He was
treated with compassionate use of favipiravir. Both his oxygen demand and fever
gradually improved after admission; however, his fever relapsed, and the
C-reactive protein (CRP) levels increased on day 7. We diagnosed his fever as
being favipiravir-induced. The fever resolved a few days after favipiravir
discontinuation, demonstrating the accuracy of the diagnosis. This case revealed
that favipiravir can induce a fever. BACKGROUND: COVID-19 caused by SARS-CoV-2 virus emerged as an unprecedented
challenge to discover effective drugs for its prevention and cure.
Hyperinflammation-induced lung damage is one of the poor prognostic indicators
causing a higher rate of morbidity and mortality of COVID-19 patients.
Favipiravir, an antiviral drug, is being used for COVID-19 treatment, and we
currently have limited information regarding its efficacy and safety. Thus, the
present study was undertaken to evaluate the adverse drug events (ADEs) reported
in the WHO pharmacovigilance database.
METHODS: This study analyzed all suspected ADEs related to favipiravir reported
from 2015. The reports were analyzed based on age, gender, and seriousness of
ADEs at the System Organ Classification (SOC) level and the individual Preferred
Term (PT) level.
RESULTS: This study is based on 194 ADEs reported from 93 patients. Most
frequent ADEs suspected to be caused by the favipiravir included increased
hepatic enzymes, nausea and vomiting, tachycardia, and diarrhea. Severe and
fatal ADEs occurred more frequently in men and those over the age of 64 years.
Blood and lymphatic disorders, cardiac disorders, hepatobiliary disorders,
injury poisoning, and procedural complications were more common manifestations
of severe ADEs.
CONCLUSION: This study revealed that favipiravir appears to be a relatively safe
drug. An undiscovered anti-inflammatory activity of favipiravir may explain the
improvement in critically ill patients and reduce inflammatory markers.
Currently, the data is based on very few patients. A more detailed assessment of
the uncommon ADEs needs to be analyzed when more information will be available. The Covid-19 pandemic is highly contagious and has spread rapidly across the
globe. To date there have been no specific treatment options available for this
life-threatening disease. During this medical emergency, target-based drug
repositioning/repurposing with a continuous monitoring and recording of results
is an effective method for the treatment and drug discovery. This review
summarizes the recent findings on COVID-19, its genomic organization, molecular
evolution through phylogenetic analysis and has recapitulated the drug targets
by analyzing the viral molecular machinery as drug targets and repurposing of
most frequently used drugs worldwide and their therapeutic applications in
COVID-19. Data from solidarity trials have shown that the treatment with
Chloroquine, hydroxychloroquine and lopinavir-ritonavir had no effect in
reducing the mortality rate and also had adverse side effects. Remdesivir,
Favipiravir and Ribavirin might be a safer therapeutic option for COVID-19.
Recent clinical trial has revealed that dexamethasone and convalescent plasma
treatment can reduce mortality in patients with severe forms of COVID-19. OBJECTIVE: The global pandemic called COVID-19 has dragged the world into a
healthcare crisis, and favipiravir is one of the most prescribed agents against
the virus so far. Favipiravir is a repurposed antiviral agent in treatment of
SARS-CoV-2 infection, and to meet the current need, pharmaceutical companies are
working for manufacturing licensed generic favipiravir. For getting the
marketing authorization, the bioequivalence of the generic product must be
proven first. The aim of this study is to demonstrate the bioequivalence of a
new favipiravir tablet formulation as compared to the reference tablet
formulation in healthy male subjects under fasting conditions.
MATERIALS AND METHODS: To prove the bioequivalence, a randomized, single oral
dose, cross-over, two-period study was carried out in 30 healthy subjects under
fasting conditions. Plasma favipiravir levels were quantified by using an
in-house-developed high performance liquid chromatography with mass spectrometry
detector (LC-MSD) method.
RESULTS: The 90% CIs for the test/reference geometric mean ratios of the Cmax
and AUC0-tlast were 88.02 - 103.11% and 98.19 - 102.06%, respectively.
CONCLUSION: This single-dose study has shown that the test and reference
favipiravir products met the required bioequivalence criteria. Besides, both
products were well tolerated and safe. As of October 2020, there is still no specific drug to treat COVID-19 as it
rages worldwide. Favipiravir, indicated for the treatment of new and re-emerging
influenza infections, has been suggested to be effective against SARS-CoV-2,
although this is not yet fully validated. We administered favipiravir to a
64-year-old female patient with COVID-19. Her symptoms resolved quickly after
the start of treatment, with reduction of SARS-CoV-2 viral load, but she
developed a fever again on day 12. Since the fever was relieved by
discontinuation of favipiravir, and based on positive results with a
drug-induced lymphocyte stimulation test, we diagnosed her with
favipiravir-induced drug fever. A decrease in the serum concentration of
favipiravir was observed along with resolution of the fever. The present case
suggests that drug fever should be considered in the differential diagnosis of
relapsing fever episodes in COVID-19 patients receiving favipiravir. Transporters in the human liver play a major role in the clearance of endo- and
xenobiotics. Apical (canalicular) transporters extrude compounds to the bile,
while basolateral hepatocyte transporters promote the uptake of, or expel,
various compounds from/into the venous blood stream. In the present work we have
examined the in vitro interactions of some key repurposed drugs advocated to
treat COVID-19 (lopinavir, ritonavir, ivermectin, remdesivir and favipiravir),
with the key drug transporters of hepatocytes. These transporters included
ABCB11/BSEP, ABCC2/MRP2, and SLC47A1/MATE1 in the canalicular membrane, as well
as ABCC3/MRP3, ABCC4/MRP4, SLC22A1/OCT1, SLCO1B1/OATP1B1, SLCO1B3/OATP1B3, and
SLC10A1/NTCP, residing in the basolateral membrane. Lopinavir and ritonavir in
low micromolar concentrations inhibited BSEP and MATE1 exporters, as well as
OATP1B1/1B3 uptake transporters. Ritonavir had a similar inhibitory pattern,
also inhibiting OCT1. Remdesivir strongly inhibited MRP4, OATP1B1/1B3, MATE1 and
OCT1. Favipiravir had no significant effect on any of these transporters. Since
both general drug metabolism and drug-induced liver toxicity are strongly
dependent on the functioning of these transporters, the various interactions
reported here may have important clinical relevance in the drug treatment of
this viral disease and the existing co-morbidities. The proverb "Old is gold" is applicable in drug discovery and the proverb "All
that Glitters is not Gold" is also appropriate. In the COVID-19 era, there has
been a race for drugs to be effective against SARS-CoV-2. There are reports
about the uses of Remdesivir and Favipiravir as existing antivirals against
virus but none have been conclusive so far. In the attempts for innovations, the
combination of drugs is also under trials. Therefore, we used the density
functional theory method and quantum theory of atoms in molecules to investigate
drug-drug interactions involving Remdesivir and Favipiravir. The computed
parameters were related to the antiviral actions of both drugs together. The
results indicate enhanced antiviral activity and it will be worthy to consider
additional investigations with the combination of these two drugs. Background: In addition to supportive therapy, antiviral therapy is an effective
treatment for coronavirus disease 2019 (COVID-19). Objective: To compare the
efficacy and safety of favipiravir and umifenovir (Arbidol) to treat COVID-19
patients. Methods: We conducted a prospective, randomized, controlled,
open-label multicenter trial involving adult patients with COVID-19. Enrolled
patients with initial symptoms within 12 days were randomly assigned in a 1:1
ratio to receive conventional therapy plus Arbidol (200 mg*3/day) or favipiravir
(1600 mg*2/first day followed by 600 mg*2/day) for 7 days. The primary outcome
was the clinical recovery rate at day 7 of drug administration (relief for
pyrexia and cough, respiratory frequency ≤24 times/min; oxygen saturation ≥98%).
Latency to relief for pyrexia and cough and the rate of auxiliary oxygen therapy
(AOT) or noninvasive mechanical ventilation (NMV)/mechanical ventilation (MV)
were the secondary outcomes. Safety data were collected for 17 days. Results: A
total of 240 enrolled COVID-19 patients underwent randomization; 120 patients
were assigned to receive favipiravir (116 assessed), and 120 patients were
assigned to receive Arbidol (120 assessed). The clinical recovery rate at day 7
of drug administration did not significantly differ between the favipiravir
group (71/116) and Arbidol group (62/120) (p = 0.1396, difference in recovery
rate: 0.0954; 95% CI: -0.0305∼0.2213). Favipiravir contributed to relief for
both pyrexia (difference: 1.70 days, p < 0.0001) and cough (difference: 1.75
days, p < 0.0001). No difference was observed in the AOT or NMV/MV rate (both p
> 0.05). The most frequently observed favipiravir-associated adverse event was
increased serum uric acid (16/116, OR: 5.52, p = 0.0014). Conclusion: Among
patients with COVID-19, favipiravir, compared to Arbidol, did not significantly
improve the clinical recovery rate at day 7. Favipiravir significantly improved
the latency to relieve pyrexia and cough. Adverse effects caused by favipiravir
are mild and manageable. BACKGROUND: Coronavirus disease (COVID-19) is an infectious disease due to
SARS-COV-2. Patients with risk factors are vulnerable to severe morbidity and
mortality. Favipiravir (FPV) and hydroxychloroquine (HCQ) are considered
possible COVID-19 treatments.
OBJECTIVE: To investigate the effectiveness and safety of FPV compared to HCQ in
patients with COVID-19 as the standard of care approved by the national protocol
there.
METHODS: This is a retrospective cohort study on patients with COVID-19 who were
administered either FPV or HCQ at King Faisal Medical Complex, Taif, Saudi
Arabia, from June 2020 to August 2020.
RESULTS: In total, 508 patients were included in the analysis. Patients were
categorized into three groups by medication. Patients enrolled in this study
were 244 (55.8%) on FPV, 193 (44.2%) on HCQ and 71 (13.81%) on neither
medication. Patients who received FPV had higher age and greater comorbidity.
Most of the patients were discharged on day 14 (n = 303, 59.6%), 26 (36.6%) in
neither med, 154 (63.1%) in FPV and 123 (63.7%) in HCQ groups with significant
difference between groups (P < 0.0001). Mortality rate was 8.2% (n = 20) in FPV
and 7.3% (n = 14) in HCQ groups with significant difference between groups (P =
0.048). Regarding drug safety, 19.7% of patients treated with FPV vs 7.8% HCQ
have adverse effects with significant difference between groups (P < 0.0001).
Most of the side effects were increase ALT and AST. Meanwhile, prolonged Q-T
interval was reported only in the HCQ group (2.6%). From Cox regression
modeling, only mechanical ventilation due to Covid 19 was predictive for
mortality (HR: 16.598, 95% CI: 7.095-38.828, P < 0.0001). Meanwhile, there was
no significant difference in the prediction of discharge of FPV (vs HCQ) (HR:
0.933, 95% CI: 0.729-1.195, P = 0.5843), predictors of mortality were HCQ (vs
FPV) (HR: 2.3, 95% CI: 0.994-5.487, P = 0.0518). Kaplan-Meier survival curves
showed improved survival time and discharged time among patients in the HCQ
versus FPV group with an insignificant difference between them (P = 0.85, P =
0.06, respectively).
CONCLUSION: The present study concluded that FPV and HCQ showed comparable
efficacy in decrease mortality and oxygen requirements. FPV likely has a more
favorable safety profile regarding cardiac toxicity. A randomized clinical trial
with large patient numbers is recommended to confirm the effectiveness of these
drugs in COVID-19 patients. |
Is MEDI2228 a bispecific antibody? | No, MEDI2228 is an antibody drug conjugate (ADC). | |
Which syndrome is caused by pathogenic COL4A3-COL4A5 variants? | Massively parallel sequencing identifies pathogenic variants in the genes affected in Alport syndrome (COL4A3-COL4A5) in as many as 30% of individuals with focal and segmental glomerulosclerosis (FSGS), 10% of those with kidney failure of unknown cause, and 20% with familial immunoglobulin A (IgA) glomerulonephritis. The population frequencies for Alport syndrome are suggested by the frequencies of predicted pathogenic COL4A3-COL4A5 variants, but must be adjusted for the disease penetrance of individual variants and for the likelihood of already diagnosed disease and non-Gly substitutions. | Massively parallel sequencing identifies pathogenic variants in the genes
affected in Alport syndrome (COL4A3-COL4A5) in as many as 30% of individuals
with focal and segmental glomerulosclerosis (FSGS), 10% of those with kidney
failure of unknown cause, and 20% with familial immunoglobulin A (IgA)
glomerulonephritis. FSGS associated with COL4A3-COL4A5 variants is usually
present by the onset of kidney failure and may develop because the abnormal
glomerular membranes result in podocyte loss and secondary hyperfiltration. The
association of COL4A3-COL4A5 variants with kidney failure or IgA
glomerulonephritis may be coincidental. However, pathogenic variants in these
conditions occur more often than they should by chance, which suggests that the
variants are disease-causing. COL4A3-COL4A5 variants are also found in cystic
kidney diseases after autosomal domit polycystic kidney disease has been
excluded. COL4A3-COL4A5 variants should be suspected in individuals with FSGS,
kidney failure of unknown cause, or familial IgA glomerulonephritis, especially
where there is persistent hematuria and a family history of hematuria or kidney
failure. BACKGROUND: The reported prevalence of Alport syndrome varies from one in 5000
to one in 53,000 individuals. This study estimated the frequencies of predicted
pathogenic COL4A3-COL4A5 variants in sequencing databases of populations without
known kidney disease.
METHODS: Predicted pathogenic variants were identified using filtering steps
based on the ACMG/AMP criteria, which considered collagen IV α3-α5 position 1
Gly to be critical domains. The population frequencies of predicted pathogenic
COL4A3-COL4A5 variants were then determined per mean number of sequenced
alleles. Population frequencies for compound heterozygous and digenic
combinations were calculated from the results for heterozygous variants.
RESULTS: COL4A3-COL4A5 variants resulting in position 1 Gly substitutions were
confirmed to be associated with hematuria (for each, P<0.001). Predicted
pathogenic COL4A5 variants were found in at least one in 2320 individuals.
p.(Gly624Asp) represented nearly half (16 of 33, 48%) of the variants in
Europeans. Most COL4A5 variants (54 of 59, 92%) had a biochemical feature that
potentially mitigated the clinical effect. The predicted pathogenic heterozygous
COL4A3 and COL4A4 variants affected one in 106 of the population, consistent
with the finding of thin basement membrane nephropathy in normal donor kidney
biopsy specimens. Predicted pathogenic compound heterozygous variants occurred
in one in 88,866 individuals, and digenic variants in at least one in 44,793.
CONCLUSIONS: The population frequencies for Alport syndrome are suggested by the
frequencies of predicted pathogenic COL4A3-COL4A5 variants, but must be adjusted
for the disease penetrance of individual variants and for the likelihood of
already diagnosed disease and non-Gly substitutions. Disease penetrance may
depend on other genetic and environmental factors. |
Is proton beam therapy used for treatment of craniopharyngioma? | Yes, proton beam therapy is used for treatment of craniopharyngioma. | PURPOSE: We report the results of the early cohort of patients treated for
craniopharyngioma with combined proton-photon irradiation at the Massachusetts
General Hospital and the Harvard Cyclotron Laboratory.
METHODS AND MATERIALS: Between 1981 and 1988, 15 patients with craniopharyngioma
were treated in part or entirely with fractionated 160 MeV proton beam therapy.
The group consisted of 5 children (median age, 15.9 years) and 10 adults (median
age, 36.2 years). Median dose prescribed to the tumor was 56.9 cobalt Gray
equivalent (CGE; 1 proton Gray = 1.1 CGE). The median proton component was 26.9
CGE. Patients were treated after documented recurrence after initial surgery (n
= 6) or after subtotal resection or biopsy (n = 9). None had had prior radiation
therapy.
RESULTS: Median observation period of surviving patients (n = 11) was 13.1 years
from radiotherapy. One patient was lost to follow-up with tumor control after
5.2 years. Actuarial 10-year survival rate was 72%. Four patients have died
5-9.1 years after treatment, two from local failure. Actuarial 5- and 10-year
local control rates were 93% and 85%, respectively. The functional status of the
living adult patients is unaltered from their preradiotherapy status; all of
them continued leading normal or near normal working lives. None of the patients
treated as a child had experienced recurrence of tumor. One child shows learning
difficulties and slight retardation, comparable to his preradiotherapy status.
The others have professional achievements within the normal range.
CONCLUSION: Results in terms of survival and local control are comparable with
other contemporary series. Although no formal neuropsychological testing was
performed, the surrogate measures of lifestyle and professional accomplishments
appear to be satisfactory. PURPOSE: We compared proton beam therapy (PBT) with intensity modulated
radiation therapy (IMRT) for pediatric craniopharyngioma in terms of disease
control, cyst dynamics, and toxicity.
METHODS AND MATERIALS: We reviewed records from 52 children treated with PBT
(n=21) or IMRT (n=31) at 2 institutions from 1996-2012. Endpoints were overall
survival (OS), disease control, cyst dynamics, and toxicity.
RESULTS: At 59.6 months' median follow-up (PBT 33 mo vs IMRT 106 mo; P<.001),
the 3-year outcomes were 96% for OS, 95% for nodular failure-free survival and
76% for cystic failure-free survival. Neither OS nor disease control differed
between treatment groups (OS P=.742; nodular failure-free survival P=.546;
cystic failure-free survival P=.994). During therapy, 40% of patients had cyst
growth (20% requiring intervention); immediately after therapy, 17 patients
(33%) had cyst growth (transient in 14), more commonly in the IMRT group (42% vs
19% PBT; P=.082); and 27% experienced late cyst growth (32% IMRT, 19% PBT;
P=.353), with intervention required in 40%. Toxicity did not differ between
groups. On multivariate analysis, cyst growth was related to visual and
hypothalamic toxicity (P=.009 and .04, respectively). Patients given radiation
as salvage therapy (for recurrence) rather than adjuvant therapy had higher
rates of visual and endocrine (P=.017 and .024, respectively) dysfunction.
CONCLUSIONS: Survival and disease-control outcomes were equivalent for PBT and
IMRT. Cyst growth is common, unpredictable, and should be followed during and
after therapy, because it contributes to late toxicity. Delaying radiation
therapy until recurrence may result in worse visual and endocrine function. INTRODUCTION: Childhood craniopharyngioma is a complex condition to manage.
Survival figures are high but the potential for long-term morbidity is great.
There is much debate regarding the best management for these tumours with
increasing interest in the use of proton beam therapy. We have therefore
reviewed our radiotherapy (RT) practice at Westmead Hospital and the literature
regarding the use of protons for these children.
METHODS: Three children have received fractionated stereotactic RT for
craniopharyngioma at Westmead Hospital since 2007. Each RT plan was reviewed and
additional organs at risk were contoured to enable comparison with published
proton data.
RESULTS: Planning target volume coverage was similar with all modalities: with
the conformity index ranging from 0.70 to 0.78 in our patients compared with
0.50-0.84 in the published data. RT dose to temporal lobes, hippocampi and whole
brain was also similar with protons and photons. Proton beam therapy may give
lower dose to the Circle of Willis than stereotactic RT.
CONCLUSION: Currently there is no clear evidence that proton beam therapy will
improve survival or reduce morbidity for children with craniopharyngioma.
However, proton therapy has the potential to reduce RT dose to the Circle of
Willis, which may reduce the risk of future cerebrovascular complications. We
propose that more resources should be allocated to ensuring these patients are
managed by experienced multidisciplinary teams through the continuum from
diagnosis to long-term follow-up. OBJECT The aim of the study was to document postoperative cerebral glucose
distribution before proton therapy using F-18 fluorodeoxyglucose positron
emission tomography (FDG PET) in children with craniopharyngioma. METHODS
Between August 2011 and April 2014, 50 patients (20 males, 30 females) enrolled
in a prospective trial for craniopharyngioma underwent FDG PET imaging before
proton therapy. Proton therapy was delivered using doublescattered beams with a
total prescribed dose of 54 cobalt gray equivalent. Tracer uptake in each of 63
anatomical regions was computed after warping PET images to a 3D reference
template in Talairach coordinates. Regional uptake was deemed significantly low
or high if it exceeded age-corresponding 95% prediction intervals of the normal
population. The reference group included 132 children with non-CNS-related
diseases and normal-appearing cerebral FDG PET scans. RESULTS Median patient age
at diagnosis was 8.5 years (range 2-18 years). Forty-eight patients underwent
1-4 tumor-related surgeries before proton therapy, including placement of an
Ommaya reservoir in 14 patients. Sixteen patients had symptomatic hydrocephalus
that was treated with temporary (external ventricular drain, n = 16) or
permanent CSF shunting (ventriculoperitoneal shunt, n = 1). The most commonly
seen PET abnormalities in patients before proton therapy were significantly
reduced uptake in subregions of the frontal lobe (often involving more than 1
gyrus), medial and ventral portions of the temporal lobe, cingulate gyrus, and
caudate nucleus. A significantly high uptake was frequently observed on the
contralateral side, including the superior, medial, and inferior temporal gyri
and a large portion of the parietal lobe. Statistically significant predictor
variables identified in the multivariate analysis for the extent of
hypometabolism were sex (p = 0.005), hydrocephalus (p = 0.026), and the number
of tumor-related surgeries (p = 0.017). CONCLUSIONS Postoperative FDG PET of
patients with craniopharyngioma revealed metabolic abnormalities in specific
regions of the brain. The ability to identify anatomical metabolic defects in
individual patients facilitates the investigation of brain injury in children
with craniopharyngioma. BACKGROUND: The unique radiobiological properties of protons have been
understood for many years. In addition, many of the clinical benefits of
radiotherapy were first noted in tumors involving the skull base. More public
attention has been given to proton beam therapy due to the increasing number of
centers now in operation or in the planning stages for offering this treatment
option.
METHODS: We reviewed the physical properties of protons and the clinical studies
performed to justify their use in the management of skull-base tumors and
determine the benefits of proton beam therapy.
RESULTS: Published reports suggest a benefit to proton beam therapy for use in
tumors of the skull base, including craniopharyngiomas, chordomas, skull-base
sarcomas, and unresectable meningiomas.
CONCLUSIONS: Use of proton beam therapy may be beneficial in select patients.
Surgical and medical oncologists should have a general understanding of such
cases to facilitate their appropriate referral. Pediatric craniopharyngioma is a rare sellar-region epithelial tumor that, in
spite of its typically benign pathology, has the potential to be clinically
devastating, and presents a host of formidable management challenges for the
skull base surgeon. Strategies in craniopharyngioma care have been the cause of
considerable controversy, with respect to both philosophical and technical
issues. Key questions remain unresolved, and include optimizing
extent-of-resection goals; the ideal radiation modality and its role as an
alternative, adjuvant, or salvage treatment; appropriate indications for
expanded endoscopic endonasal surgery as an alternative to transcranial
microsurgery; risks and benefits of skull base techniques in a pediatric
population; benefits of and indications for intracavitary therapies; and the
preferred management of common treatment complications. Correspondingly, we
sought to review the preceding basic science and clinical outcomes literature on
pediatric craniopharyngioma, so as to synthesize overarching recommendations,
highlight major points of evidence and their conflicts, and assemble a general
algorithm for skull base surgeons to use in tailoring treatment plans to the
individual patient, tumor, and clinical course. In general terms, we concluded
that safe, maximal, hypothalamic-sparing resection provides very good tumor
control while minimizing severe deficits. Endoscopic endonasal,
intraventricular, and transcranial skull base technique all have clear roles in
the armamentarium, alongside standard craniotomies; these roles frequently
overlap, and may be further optimized by using the approaches in adaptive
combinations. Where aggressive subtotal resection is achieved, patients should
be closely followed, with radiation initiated at the time of progression or
recurrence-ideally via proton beam therapy, although three-dimensional conformal
radiotherapy, intensity-modulated radiotherapy, and stereotactic radiosurgery
are very appropriate in a range of circumstances, governed by access, patient
age, disease architecture, and character of the recurrence. Perhaps most
importantly, outcomes appear to be optimized by consolidated, multidisciplinary
care. As such, we recommend treatment in highly experienced centers wherever
possible, and emphasize the importance of longitudinal follow-up-particularly
given the high incidence of recurrences and complications in a benign disease
that effects a young patient population at risk of severe morbidity from
hypothalamic or pituitary injury in childhood. BACKGROUND: The clivus is a region characterized by complex anatomy, with
vascular and neural structures that are located in close proximity. Different
pathologies can affect this area, and traditional surgical approaches were open
approaches. Recently, the endoscopic transnasal technique has been introduced,
and currently represents a good alternative for the surgical management of these
lesions. This is a preliminary report on patients treated endoscopically for
clival lesions by the authors' Skull Base Team.
PATIENTS AND METHODS: This was a retrospective chart review of patients who
underwent an endoscopic exclusive transnasal approach (EEA) or a transoral one
(TO) for clival lesions between June 2015 and November 2017 at our Skull Base
Referral Center. Patient characteristics and symptoms, preoperative
neuroradiological evaluation, surgical approach, complications, and
postoperative results were evaluated.
RESULTS: Nine patients (6 females and 3 males; age range 6-82 years, mean
50.8 years) underwent EEA or TO. From histological analysis, we found chordomas
(6/9 subjects), chondrosarcoma (1/9), craniopharyngioma (1/9), and eosinophilic
granuloma (1/9). Three patients had previously been operated for a parasellar
chondrosarcoma (1/9), a pituitary macroadenoma (1/9), or a chondroid chordoma
(1/9). The lesions were totally (2/9) or sub-totally (5/9) resected, debulked
(1/9), or analyzed with a biopsy (1/9). Reconstruction was accomplished with a
multilayer technique (7/9), or with a gasket-seal (1/9), using a
mucoperichondrial graft, a single/double nasoseptal flap, a middle turbinate
flap, a fascia lata, or a synthetic fascia. One patient (11.1%) was re-operated
on due to cerebrospinal leakage, without further complications. Two patients
(22.2%) were re-operated on due to chordoma regrowth. Adjuvant chemotherapy was
administered to 1/9 patient with progressive healing. All of the other patients
underwent proton-beam radiotherapy with no documented tumor growth (median
follow-up: 20 months; range 5.1-29.9 months).
CONCLUSIONS: Clival lesions represent a heterogeneous group of lesions located
in a very complex and difficult area. EEA and TO approaches are safe and
mini-invasive, with lower morbidity and with postoperative complications when
compared to the traditional open approaches, according to the extent and type of
pathology. BACKGROUND: Childhood brain tumor diagnoses are stressful for families. Children
diagnosed with craniopharyngioma (Cp) present with particularly challenging
medical and cognitive problems due to tumor location and associated
biophysiologic comorbidities. This study examined parental distress in a sample
of families of patients with Cp treated with proton beam therapy to identify
factors for targeting psychological intervention.
PROCEDURE: Prior to (n = 96) and 1 year after (n = 73) proton therapy, parents
of children diagnosed with Cp (9.81 ± 4.42 years at baseline; 49% male)
completed a self-report measure of distress, the Brief Symptom Inventory (BSI).
Children completed cognitive assessment measures at baseline; medical variables
were extracted from the study database.
RESULTS: At baseline, t-tests revealed parents reported higher levels of
distress than normative expectations on Anxiety, Depression, Global Severity,
and Positive Symptom Distress BSI scales (P < 0.05). Linear mixed effects models
revealed parent report measures of child executive dysfunction and behavioral
issues were more predictive of parental distress than patients' cognitive
performance or medical status (P < 0.05). Models also revealed a significant
reduction only in Anxiety over time (t = -2.19, P < 0.05). Extensive
hypothalamic involvement at baseline predicted this reduction (P < 0.05).
CONCLUSION: Parents experience significant distress before their child begins
adjuvant therapy for Cp, though parental distress appears largely unrelated to
medical complications and more related to parent perceptions of child cognitive
difficulties (vs. child performance). Importantly, this may be explained by a
negative parent reporting style among distressed parents. Knowledge of
socio-emotional functioning in parents related to patient characteristics is
important for optimization of psychological intervention. OBJECTIVE: The management of children with craniopharyngioma has evolved over
time, with a trend toward less invasive neurosurgical approaches as surgeons
have sought to balance oncological control and treatment-related morbidity. To
this end, the aim of this study was to evaluate the safety and effectiveness of
the current management of children with craniopharyngioma compared to the
previous management methods used at the authors' treatment center.
METHODS: A prospectively maintained database was searched over a 14-year period
between January 1, 2005, and December 31, 2018, to identify all children 17
years of age or younger with a new diagnosis of craniopharyngioma. A
retrospective case note review was performed for each child to extract data on
the presentation, investigation, treatment, and outcome of their illness.
Morbidity was assessed in the same fashion as in previous cohorts, according to
the following categories: visual loss, pituitary dysfunction, hypothalamic
dysfunction, neurological deficits, and cognitive impairment.
RESULTS: In total, 59 children were identified with craniopharyngioma during the
study period. A total of 92 operations were performed, including cyst drainage
(35/92; 38.0%), craniotomy and resection (30/92; 32.6%), and transsphenoidal
resection (16/92; 17.4%). Approximately two-thirds of all operations were
performed using image guidance (66/92; 71.7%) and one-third were performed using
endoscopy (27/92; 29.3%). The majority of children had adjuvant therapy
comprising proton beam therapy (18/59; 30.5%) or conventional radiotherapy
(16/59; 27.1%). The median follow-up duration was 44 months (range 1-142
months), and approximately one-half of the children had no evidence of residual
disease on MRI studies (28/59; 47.5%). Of the remaining 31 children, there was a
reduction in the volume of residual disease in 8 patients (8/59; 13.6%), stable
residual disease in 18 (18/59; 30.5%), and tumor growth in 5 patients (5/59;
8.5%). There was significantly reduced morbidity (p < 0.05) in all categories in
the current cohort compared with our last cohort (1996-2004).
CONCLUSIONS: The authors' institutional experience of pediatric
craniopharyngioma confirms a trend toward less invasive neurosurgical
procedures, most of which are now performed with the benefit of image guidance
or endoscopy. Moreover, the authors have identified an expanding role for more
targeted radiotherapy for children with residual disease. These advances have
allowed for tumor control comparable to that achieved in previous cohorts, but
with significantly reduced morbidity and mortality. We recently started India's first proton beam therapy facility. Proton beam
therapy because of its unique physical characteristics of minimal exit dose has
an unequivocal dosimetric superiority over high-end photon/standard X-ray beam
therapy and is particularly advantageous in growing children with curable
cancers in view of their very high probability of long-term cures. We hereby
report a case of a 7-year-old boy with a craniopharyngioma which had been
subtotally resected and was subsequently treated with modern pencil beam proton
therapy under high-precision image guidance. This is the first ever child ever
to be treated with proton therapy in India. BACKGROUND AND PURPOSE: This study analyses the dosimetric and dose averaged
Linear Energy transfer (LETd) correlation in paediatric craniopharyngioma (CP)
patients with and without radiation-induced cerebral vasculopathies (RICVs)
treated with pencil beam scanning (PBS) proton therapy (PT).
MATERIAL AND METHODS: We reviewed a series of 16 CP patients treated with PT to
a median dose of 54 Gy(RBE). Two (12.5%) index patients presented RICVs 14 and
24 months (median, 19) after PT. Organs at risks (OARs) as bilateral internal
carotid arteries (ICAs) and circle of Willis were contoured based on CTs and
MRIs pre- and post-PT. Dosimetry was reviewed and LETd distributions were
calculated; LETd metric for PTVs and OARs were analysed. For a sub-cohort,
dosimetric and LETd values robustness due to range uncertainties were computed.
RESULTS: For the two index patients, no correlation was observed between RICVs
and OARs doses. However for those patients mean(maximum) LETd values in the
affected OARs were up to 4.0 ± 0.4 (7.8 ± 0.1)keV/μm; those LETd values were
significantly higher (p = 0.02) than the mean(maximum) LETd values for the rest
of the cohort (mean: 3.1 ± 0.3, maximum: 4.8 ± 1.0 keV/μm). This was due to
asymmetric field arrangement, thus resulting in marked asymmetric LETd
distributions. For such arrangement, maximum LETd values variations in vascular
structures due to range uncertainties were up to 1.2 keV/μm, whilst for the
symmetric one they were up to 0.7 keV/μm.
CONCLUSIONS: For children with and without RICVs, quantitative analysis showed a
significant correlation with LETd average/maximum values in vascular structures,
whilst no correlation was found on dosimetric parameters. |
What are the phases of hair follicle cycle? | Hair follicle cycle phases (anagen, catagen and telogen) | Dihydrotestosterone (DHT) and 17β-estradiol (E2) are sex hormones that regulate
human hair follicle (HF) growth and are produced by peripheral reduction and
aromatization of testosterone. However, the expression patterns of DHT and E2
synthesis-related proteins and their receptors in male yak skin during different
HF stages (telogen, anagen, and catagen) are unknown. In this study, we found
that both 5α-red and androgen receptor (AR) were expressed in epithelial cells
and AR was expressed in the dermal papilla. Additionally, the transcription
level of 5α-red1 at different HF stages was significantly higher than that of
5α-red2 mRNA at the same stage; 5α-red1 and 5α-red2 proteins peaked during the
anagen and telogen periods of HF, respectively. However, AR protein was only
expressed in the skin during the anagen phase of HF. Aromatase and estrogen
receptors (ERα and ERβ) were expressed in cutaneous epithelial cells, whereas
ERα and ERβ were expressed in the dermal papilla; the transcription level of ERα
in HFs at each stage was much higher than that of ERβ. From the catagen to
telogen phase, aromatase protein expression was down-regulated, while ERα
protein expression was up-regulated. Based on our results, we speculate that
5α-red1 is essential for the synthesis of DHT in male yak skin epithelial cells
and promotes the growth of HFs through AR. E2 synthesized by male yak skin
epithelial cells may inhibit the growth of male yak skin HFs by ERα. These
results provide a foundation for further study on the mechanism of
hormone-regulated male yak skin HFs. Hair follicle stem cells (HFSCs) are maintained in a quiescent state until
activated to grow, but the mechanisms that reactivate the quiescent HFSC
reservoir are unclear. Here, we find that loss of Sirt7 in mice impedes hair
follicle life-cycle transition from telogen to anagen phase, resulting in delay
of hair growth. Conversely, Sirt7 overexpression during telogen phase
facilitated HSFC anagen entry and accelerated hair growth. Mechanistically,
Sirt7 is upregulated in HFSCs during the telogen-to-anagen transition, and
HFSC-specific Sirt7 knockout mice (Sirt7f/f ;K15-Cre) exhibit a similar hair
growth delay. At the molecular level, Sirt7 interacts with and deacetylates the
transcriptional regulator Nfatc1 at K612, causing PA28γ-dependent proteasomal
degradation to terminate Nfatc1-mediated telogen quiescence and boost anagen
entry. Cyclosporin A, a potent calcineurin inhibitor, suppresses nuclear
retention of Nfatc1, abrogates hair follicle cycle delay, and promotes hair
growth in Sirt7-/- mice. Furthermore, Sirt7 is downregulated in aged HFSCs, and
exogenous Sirt7 overexpression promotes hair growth in aged animals. These data
reveal that Sirt7 activates HFSCs by destabilizing Nfatc1 to ensure hair
follicle cycle initiation. |
What is the cause of Bow Hunter's syndrome? | Bow hunter's syndrome (BHS) is caused by posterior circulation insufficiency that results from the occlusion or compression of the vertebral artery (VA) during neck rotation. | Bow hunter's stroke results from vertebrobasilar insufficiency caused by
mechanical occlusion or stenosis of the vertebral artery (VA) at the C1-2 level
on head rotation. Surgical treatment of this condition may be chosen to avoid
life-threatening accidents or because patients complain that conservative
treatments such as verbal warnings or use of a neck brace to limit head and neck
rotation are ineffective and thus restrict their lifestyle. Posterior fusion
involving C1-2 has long been used to limit atlantoaxial rotational movements.
However, it has the serious disadvantage that the range of head motion is
severely reduced. Recently, decompression of the atlantoaxial portions of the
affected VA has been used because it does not limit physiological neck
movements. However, no long-term follow-up review of patients who have undergone
this procedure has been conducted, and it is unclear whether this procedure
always provides relief of symptoms. To answer this question, the results of C1-2
posterior fusion were compared with decompression of the VA for the treatment of
bow hunter's stroke. OBJECTIVE AND IMPORTANCE: Bow hunter's stroke is a symptomatic vertebrobasilar
insufficiency caused by stenosis or occlusion of the vertebral artery at the
C1C2 level with head rotation. No case of anterior decompression of the
vertebral artery for surgical treatment of bow hunter's stroke has been
reported.
CLINICAL PRESENTATION: A 47-year-old male patient presented with repeated
episodes of unconsciousness caused by turning his head approximately 40 degrees
to the right; he recovered consciousness within approximately 10 seconds after
his head was returned to the neutral position. Angiography revealed an occluded
right vertebral artery and temporary occlusion of the left vertebral artery, at
the level of the C2 transverse foramen, when the patient's head was turned
approximately 40 degrees to the right.
INTERVENTION: Anterior decompression of the left vertebral artery at the
transverse foramen of the axis was performed. Postoperative angiography
demonstrated sufficient flow in the left vertebral artery even when the neck was
rotated.
CONCLUSION: The patient was discharged without neurological deficits. We
demonstrate that simple surgical untethering of the vertebral artery at the
transverse foramen of the axis is an effective method of treatment that avoids
the limitation of head rotation. The advantage of this procedure is that it does
not result in postoperative restriction of the patient's neck movements. The
anterior approach, with decompression of the transverse foramen of the axis, in
the present case provided adequate exposure of the vertebral artery and resulted
in a satisfactory outcome. STUDY DESIGN: A case report.
OBJECTIVE: To illustrate a rare case of bow hunter's syndrome in a patient with
significant contralateral vertebral artery (VA) occlusive disease.
SUMMARY OF BACKGROUND DATA: Bow hunter's syndrome is an uncommon condition in
which the VA is symptomatically occluded during neck rotation. This case is
interesting in that the patient had what appeared to be a normal right VA and
occluded left VA when the head was in the neutral position. When the head was
rotated 45 degrees to the left, the patient's right VA was occluded (bow
hunter's finding), and it became apparent that the left VA was not completely
occluded (as it appeared in the neutral position angiogram) but rather was 90%
stenosed. The complete occlusion appearance in the neutral position was an
angiographic phenomenon caused by competitive flow through the open right VA.
When the patient rotated his head to the left, he occluded his right VA and had
insufficient blood flow through the left VA, thus creating a symptomatic
ischemic state.
METHODS: This case was studied using dynamic computed tomography imaging,
single-photon emission computed tomography, transcranial Doppler ultrasound,
brain stem auditory evoked potentials, and dynamic range-of-motion cerebral
angiography.
RESULTS: The patient demonstrated bow hunter's syndrome as documented on
clinical examination and history. Transcranial Doppler studies, dynamic computed
tomography scanning, and cerebral/cervical angiography confirmed the diagnosis
and revealed an interesting angiographic pattern, which explained the patient's
symptoms and findings only when angiographic flow patterns were taken into
consideration.
CONCLUSIONS: Bow hunter's syndrome should be suspected when a patient presents
with reproducible vertebrobasilar symptoms on rotating the neck. Quantitative
documentation using imaging and electroneurophysiologic tests is important when
assessing this subjective process. Careful evaluation of the angiographic
imagescan often help explain an odd flow pattern and provide the physician with
a range of treatment options. Rotational movements in the territory of vertebrobasilar artery of the head and
neck can induce vertebrobasilar insufficiency (VBI) or infarction. The term "bow
hunter's stroke" or "rotational VBI" has been used to describe this clinical
syndrome. In most cases, symptoms were provoked because of involvement of a
domit vertebral artery (VA) with hypoplasia or occlusion of the contralateral
VA. The author presented a case in which bow hunter's stroke was caused by
occlusion of a non-domit VA ending in the posterior inferior cerebellar
artery (PICA). Diagnosis of rotational VBI was based on stereotypical clinical
symptoms related to head rotation and hemodynamic study of the effects of head
rotation. VA compression was documented in dynamic ultrasonography including the
disappearance of end-diastolic flow in extracranial portion of VA and marked
reduction in blood flow velocity (more than 50%) in the intracranial portion of
VA upon head rotation. We emphasize that rotational occlusion of this anatomical
variation is an important cause of VBI. This may cause permanent neurological
deficits if left undiagnosed. Bow hunter's syndrome (BHS) is caused by transient vertebro-basilar ischemia on
head rotation. We report a patient with BHS who was identified from dynamic
changes to blood flow velocities in the posterior cerebral, basilar and
vertebral arteries using carotid duplex ultrasonography and transcranial
Doppler, simultaneously. Neurosonology appears to be useful for diagnosing and
evaluating BHS. Bow hunter's stroke (BHS) is a cerebrovascular disease caused by occlusion of
the vertebral artery (VA) on head rotation. BHS is generally associated with
hemodynamic changes, often leading to vertebrobasilar insufficiency symptoms,
such as vertigo and faintness. Although artery-to-artery embolism has also been
proposed as an underlying mechanism, it remains controversial. This report
documents a case of BHS without hemodynamic changes. We describe a 26-year-old
male patient who had VA occlusion on head rotation and repetitive infarction of
thalami. He had an anomalous bypass of the VA and therefore no symptomatic
hemodynamic changes. Thus, non-hemodynamic BHS should be considered in juvenile
patients with vertebrobasilar stroke. Bow hunter's syndrome is characterized by transient vertebrobasilar
insufficiency that is elicited by neck rotation. This syndrome is has various
causes, such as osteophytes, tumors, fibrous bands, infection, and trauma. We
report a unique case of bow hunter's syndrome. The patient visited our hospital
because of left nuchal pain. A magnetic resoce imaging scan revealed left
vertebral artery (VA) dissection, which was the cause of his nuchal pain. He
began to feel faintness upon turning his neck to the left after left VA
dissection. Digital subtraction angiography revealed that the right VA was fully
patent in a neutral neck position, but focal stenosis appeared at the C2
vertebral level upon turning his head 60° to the left. This stenosis became
complete occlusion at turning his head to the end of his range of motion. From
these findings, a diagnosis of bow hunter's syndrome was made. Dissection of the
contralateral (left) VA caused a failure in compensatory blood flow, resulting
in bow hunter's syndrome. This represents the first report of bow hunter's
syndrome occurring after onset of the contralateral VA dissection. Rotational occlusion of the vertebral artery (VA), or bow hunter's syndrome, is
a rare yet surgically treatable cause of vertebrobasilar insufficiency. The
underlying pathology is dynamic stenosis of the VA by osteophytes, fibrous
bands, or lateral disc herniation with neck rotation or extension. The authors
present 2 previously unreported cases of bow hunter's syndrome and summarize 124
cases identified in a literature review. Both patients in the new cases were
treated by VA decompression and fusion of the subaxial spine. Each had > 50%
occlusion of the left VA at the point of entry into the transverse foramen with
a contralateral VA that ended in the posterior inferior cerebellar artery.
Analyzing data from 126 cases (the 2 new cases in addition to the previously
published 124), the authors report that stenosis was noted within V1 in 4% of
cases, in V2 in 58%, in V3 in 36%, and distal to C-1 in 2%. Patients presented
in the 5th to 7th decade of life and were more often male than female. The
stenotic area was decompressed in 85 (73%) of the 116 patients for whom the type
of treatment was reported (V1, 4 [80%] of 5; V2, 52 [83%] of 63; V3/V4, 29 [60%]
of 48). Less commonly, fusion or combined decompression and fusion was used (V2,
7 [11%] of 63; V3/V4, 14 [29%] of 48). Most patients reported complete
resolution of symptoms. The authors conclude that patients with bow hunter's
syndrome classically have an impaired collateral blood flow to the brainstem.
This condition carries an excellent prognosis with decompression, fusion, or
combined surgery, and individual patient characteristics should guide the choice
of therapy. BACKGROUND: Vertebral artery compression by cervical osteophyte is a rare cause
of vertebrobasilar ischemic stroke. This mechanism of stroke has been reported
as the Bow Hunter syndrome defined by vertebrobasilar insufficiency because of
mechanical stenosis of the vertebral artery at the cervical level triggered by
head movement. The most common treatment is surgical decompression. However, in
most cases, a domit vertebral artery is involved, and its dynamic extrinsic
compression is demonstrated on angiography.
CASE REPORT: We report a patient with recurrent posterior circulation
infarctions because of the compression of a nondomit vertebral artery by a
cervical osteophyte. The dynamic angiography did not show any worsening of the
vertebral stenosis by head movements but an irregularity of the vertebral artery
with regard to the osteophyte compression, suggesting a direct artery wall
injury. We concluded to an embolic mechanism through thrombus formation from the
artery wall injury at the stenosed site. Because neither surgical decompression
nor stenting was deemed to be a relevant treatment option, endovascular coil
embolization of the compressed vertebral artery was performed after a clamping
test to check the efficiency of the collateral circulation. The procedure was a
success. During the 12-month follow-up, the patient did not have any recurrent
stroke.
CONCLUSIONS: In case of recurrent symptomatic extrinsic compression of a
nondomit vertebral artery, endovascular embolization after a clamping test
may be considered. BACKGROUND: Bow Hunter's Syndrome is a mechanical occlusion of the vertebral
artery which leads to a reduction in blood flow in posterior cerebral
circulation resulting in transient reversible symptomatic vertebrobasilar
insufficiency.
CASE DESCRIPTION: We present a case of Bow Hunter's syndrome in a 53-year-old
male that occurred after the patient underwent surgical correction of a proximal
left subclavian artery aneurysm. Shortly after the surgery, the patient began to
complain of transient visual changes, presyncopal spells, and dizziness upon
turning his head to the left. A transcranial doppler ultrasound confirmed the
diagnosis of Bow Hunter's syndrome.
SYSTEMIC REVIEW: We analyzed the data on 153 patients with Bow Hunter's syndrome
from the literature. An osteophyte was the most common cause of vertebral artery
occlusion, and left vertebral artery was more commonly involved in patients with
Bow Hunter's syndrome. Dynamic angiography was the definitive imaging modality
to confirm the diagnosis, and surgery was most successful in alleviating
symptoms.
CONCLUSION: We believe that this is the first case of iatrogenic Bow Hunter's
syndrome after surgical intervention for an aneurysm repair, and the largest
review of literature of Bow Hunter's syndrome. Dynamic angiography is the gold
standard for the diagnosis of Bow Hunter's syndrome. Surgery should be
considered as the primary treatment approach in these patients, especially those
who have bony compression as the etiology. Rotational vertebral artery occlusion, also known as bow hunter's syndrome, is a
well-documented surgically amenable cause of vertebrobasilar insufficiency.
Traditionally, patients have been imaged using dynamic rotational angiography.
The authors sought to determine whether intraoperative indocyanine green (ICG)
angiography could reliably assess the adequacy of surgical decompression of the
vertebral artery (VA). The authors report two patients who presented with
multiple transient episodes of syncope provoked by turning their head to the
right. Rotational dynamic angiography revealed a domit VA that became
occluded with head rotation to the right side. The patients underwent successful
surgical decompression of the VA via an anterior cervical approach.
Intraoperative ICG angiography demonstrated patency of the VA with head
rotation. This was further confirmed by intraoperative dynamic catheter
angiography. To our knowledge, we present the first two cases of the use of ICG
combined with intraoperative dynamic rotational angiography to document the
adequacy of surgical decompression of the VA in a patient with rotational
vertebral artery occlusion. Intraoperative ICG angiography is a useful adjunct
and may potentially supplant the need for intraoperative catheter angiography. Rotational vertebrobasilar insufficiency, or bow hunter's syndrome, is a rare
cause of posterior circulation ischemia, which, following rotation of the head,
results in episodic vertigo, dizziness, nystagmus, or syncope. While typically
caused by dynamic occlusion of the vertebral artery in its V2 and V3 segments,
the authors here describe a patient with dynamic occlusion of the vertebral
artery secondary to a persistent first intersegmental artery, a rare variant
course of the vertebral artery. In this case the vertebral artery coursed under
rather than over the posterior arch of the C-1. This patient was also found to
have incomplete development of the posterior arch of C-1, as is often seen with
this variant. The patient underwent dynamic digital subtraction angiography,
which demonstrated occlusion at the variant vertebral artery with head turning.
He was then taken for decompression of the vertebral artery through removal of
the incomplete arch of C-1 that was causing the dynamic compression. After
surgery the patient had a complete resolution of symptoms. In this report, the
authors present the details of this case, describe the anatomical variants
involved, and provide a discussion regarding the need for atlantoaxial fusion in
these patients. Bow Hunter's syndrome is an unusual symptomatic vertebrobasilar insufficiency
resulting from intermittent mechanical compression of the vertebral artery, and
is rarely a trigger for cerebral infarction following thrombus formation on the
damaged endothelial vessels (Bow Hunter's stroke). The authors present an
extremely rare case of a 45-year-old man showing Bow Hunter's stroke due to
congenital vertebral artery fenestration stretching and sliding between C1 and
C2 after head rotation to the right. Congenital vertebral artery anomaly rarely
causes cerebral infarction, but could cause embolic strokes by mechanical
stretching without bony abnormalities. Vertebrobasilar insufficiency (VBI) provoked by physiological head rotation is
known as rotational vertebral artery syndrome (RVAS) or Bow Hunter syndrome.
RVAS most often occurs at C1-2 level with head rotation and presents with
symptoms of VBI. Several previously published studies have reported RVAS at
subaxial sites (V2 segment), however, tumor-induced RVAS has never been
reported. The authors report the first case of RVAS at V2 segment due to
compression from a spinal tumor. A 71-year-old man presented with symptoms of
dizziness provoked by head rotation or neck extension. computed tomography (CT)
angiography and dynamic cerebral angiography revealed circumferential stenosis
with neutral neck position and complete occlusion of the left domit vertebral
artery (VA) at C5 level with his neck extended or rotated to the left. Complete
neurological recovery was achieved after removal of a spinal osteochondroma and
surgical decompression of the left VA via an anterior approach. Spinal tumors
should be included in the differential diagnosis in cases of RVAS. Spinal
degenerations or sarcomatous transformation of the tumor could lead to clinical
manifestations of RVAS in cases with spinal osteochondroma. Complete removal of
the tumor with or without spinal fusion would be the treatment of choice, in
addition to medical treatment in the cases of acute stroke. Bow Hunter's syndrome (BHS) is a rare cause of vertebrobasilar insufficiency and
is reported to most commonly be caused by vertebral artery impingement on
cervical vertebrae osteophytes. We report a case in a 56-year-old male patient
who on investigation of recurrent posterior circulation ischaemic strokes was
found to have BHS. The aetiology of the syndrome in this patient is due to a
particularly unusual aberrancy in the path of the atlantoaxial portion of the
culprit left vertebral artery. Aberrancy of the distal portion of the vertebral
artery is in itself a rare entity, and there are few reports of it in relation
to BHS. The patient in this case was successfully treated with endovascular
sacrifice of the vertebral artery with no further dynamic occlusive symptoms. BACKGROUND: Bow hunter's syndrome (BHS), also known as rotational vertebral
artery occlusion syndrome, is rare. Occasionally, it combines with
dissection/pseudoaneurysm of the ipsilateral VA.
METHODS: We report a case of BHS combined with ipsilateral VA
dissection/pseudoaneurysm and review eight similar cases reported in the
literature. Their aetiology, clinical and imaging features, treatment, and
prognosis were analysed.
RESULTS: Nine patients (seven male, two female; average age 22.0 ± 4.5 years)
were enrolled. Visual symptoms comprised the most common clinical finding
(66.7%, 7/9). Clinical symptoms were not related to neck rotation in seven
patients (77.8%). Eight patients (88.9%) had multiple, scattered, new and old
infarctions of the posterior circulation revealed on computed
tomography/magnetic resoce imaging (CT/MRI) scans. Dissection/pseudoaneurysm
was found in the ipsilateral VA - usually subtle and localised in the atlas,
axis, and occipital bone - in all nine patients. Seven patients (66.7%) had
special causes for the syndrome (i.e. congenital bone dysplasia). Altogether,
87.5% (7/8) experienced recurrence with cerebral infarction after antithrombotic
therapy alone. Aetiologically targeted treatment, including surgical
decompression or vertebral fixation, was performed in seven patients (77.8%).
CONCLUSION: Young patients presenting with cryptogenic stroke in the posterior
circulation and localised, subtle dissection/pseudoaneurysm of the ipsilateral
VA around the atlanto-axial joint should undergo carotid ultrasonography with a
neck rotation test or dynamic CT angiography/MR angiography/digital subtraction
angiography, if necessary, to rule out/diagnose BHS. BACKGROUND: Bow hunter's syndrome (BHS) is caused by posterior circulation
insufficiency that results from the occlusion or compression of the vertebral
artery (VA) during neck rotation. Owing to its rarity, there is no guideline to
support the decision of selecting a conservative or a surgical approach.
Management of BHS is dependent on each patient.
CASE DESCRIPTION: A 13-year-old girl presented with transient visual
disturbance, hypoesthesia, and paralysis of the left side of the body. Magnetic
resoce imaging revealed an acute cerebral infarction in the right thalamus,
and magnetic resoce angiography demonstrated occlusion of the right posterior
cerebral artery and dilation of V3 of the left VA. Digital subtraction
angiography revealed a left VA dissecting aneurysm at V3 and left VA occlusion
at the level of C1-C2 during neck rotation to the right. A dynamic x-ray
suggested atlantoaxial joint instability, and three-dimensional computed
tomography revealed aplasia of C1 lamina and atlantoaxial rotatory dislocation.
BHS with left VA dissecting aneurysm caused by atlantoaxial rotatory dislocation
was diagnosed. We performed C1-C2 posterior fusion by the Goel-Harms technique.
Stroke did not recur, and computed tomography angiography obtained 8 months
postoperatively demonstrated a decrease in the dissecting aneurysm.
CONCLUSIONS: To our knowledge, this is the first case of BHS with VA dissecting
aneurysm and aplasia of C1 lamina. Based on this case, we suggest that C1-C2
posterior fusion is effective for BHS with VA dissecting aneurysm. BACKGROUND: Bow hunter's syndrome, or occlusion of the vertebral artery with
head rotation leading to ischemia and sometimes stroke, is rarely described in
children. The authors review the literature and present a new case.
METHODS: Both OVID dating back to 1946 and PubMed records were reviewed using
the terms ("Bow hunter syndrome" OR "bow hunter's") OR "rotational vertebral
artery occlusion" combined with "child," and limited to English language. SCOPUS
and the bibliographies of cases found in the search were used to identify
additional articles.
RESULTS: Twelve articles were found describing 25 patients; there were 26
patients when combined with our case. Ages ranged from 1 to 18 years. Most
(88.5%, 23/26) were male. Medical treatments included aspirin, clopidogrel,
abciximab, enoxaparin, warfarin, and cervical collar. Stenting was tried in 2
cases but did not work long-term. Surgical treatments included decompression,
cervical fusion, or a combination. We present a new case of a 12-year-old girl
with recurrent stroke who had bilateral vascular compression only visible on
provocative angiographic imaging with head turn. She was referred for cervical
fusion, and abnormal ligamentous laxity was noted intraoperatively.
CONCLUSIONS: Bow hunter's syndrome is a rare but important cause of stroke since
many of the patients experience recurrent strokes before the diagnosis is made.
Reasons for the male predomice are unclear. Provocative angiography plays a
key role in diagnosis, and both medical treatment and neurosurgical intervention
may prevent recurrence. Bow Hunter's syndrome is extremely rare, which is mainly caused by mechanical
vertebral artery occlusion or stenosis during head and neck rotation or
hyperextension. Herein, we describe the case of a 19-year-old man without a
history of trauma who presented with dizziness, binocular blackness, and
disturbance of consciousness after looking up when cleaning the classroom.
Subsequent imaging findings revealed the blood flow of the C2 segment of the
contralateral vertebral artery was interrupted when the patient turned his head
to 1 side. Such patients with normal CT angiography of the head and neck scan
will show that the head and neck blood vessels are normal, which will affect the
prognosis of patients. This case highlights the importance and implications of
dynamic CT angiography of the head and neck in the diagnosis of Bow Hunter's
syndrome. Bow hunter's syndrome is due to vertebrobasilar insufficiency caused by
rotational compression of the vertebral artery. We report a case in which an
osteophyte compressed the left vertebral artery causing cerebellar stroke. The
patient underwent successful resection of the osteophyte via anterior surgical
approach, and his symptoms of headache and dizziness dissipated postoperatively.
This unique syndrome has been treated with multiple modalities and must remain
in the clinician's differential as a treatable cause of stroke. Bow hunter's syndrome (BHS) is most commonly caused by compression of the
vertebral artery (VA). It has not been known to occur due to an extracranially
originated posterior inferior cerebellar artery (PICA), the first case of which
we present herein. A 71-year-old man presented with reproducible dizziness on
leftward head rotation, indicative of BHS. On radiographic examination, the
bilateral VAs merged into the basilar artery, and the left VA was predomit.
The right PICA originated extracranially from the right VA at the atlas-axis
level and ran vertically into the spinal canal. During the head rotation that
induced dizziness, the right PICA was occluded, and a VA stenosis was revealed.
Occlusion of the PICA was considered to be the primary cause of the dizziness.
The patient underwent surgery to decompress the right PICA and VA via a
posterior cervical approach. Following surgery, the patient's dizziness
disappeared, and the stenotic change at the right VA and PICA improved. The PICA
could be a causative artery for BHS when it originates extracranially at the
atlas-axis level, and posterior decompression is an effective way to treat it. |
What types of anti-tumor therapeutic antibodies are available? | Anti-tumor therapeutic antibodies include single-targeted antibodies, bi-specific antibodies (BsAbs), and antibody-drug conjugates (ADCs). | |
Which disease do pathogenic NR2F1 variants cause? | Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) is an autosomal-dominant disorder characterized by optic atrophy and intellectual disability caused by loss-of-function mutations in NR2F1. | |
Which mutation is targeted by Tepotinib? | MET Exon 14 Skipping Mutation is targeted by Tepotinib that is used for patients with non-small-cell lung cancer. | The MET exon 14 skipping mutation is found in approximately 3% of lung
adenocarcinomas and slightly more than 2% of lung squamous cell carcinomas. In
recent years, more and more evidence has shown that MET inhibitors have achieved
good anti-tumor effect in patients with MET exon 14 skipping mutation,
suggesting that MET exon 14 skipping mutation may be a new target for NSCLC
patients. Patients with positive MET exon 14 skipping mutation are recommended
to be administered MET inhibitors, and crizotinib is recommended by the NCCN
guideline. Due to the presence of gene amplification, second site mutation,
bypass activation, and pathological type transformation, one of the inevitable
problems of targeted therapy is drug resistance. If type I MET inhibitors
(crizotinib, capmatinib, tepotinib, savolitinib) drug resistance is developed,
type II MET inhibitors (cabozantinib, glesatinib, merestinib) can be considered. Mesenchymal-epithelial transition factor (MET) gene is an important tumor driver
gene of non-small cell lung cancer (NSCLC). Drugs targeting MET 14 exon skipping
mutation bring new hope to patients. MET inhibitors that are currently on the
market or are about to be marketed include: crizotinib, cabozantinib,
savolitinib and tepotinib. The objective response rate of MET inhibitors is
high, and the safety is good. However, resistance of MET-tyrosine kinase
inhibitor (TKI) is inevitable, so it is necessary to pay attention to the study
of drug resistance mechanism. In addition, the combined use of hepatocyte growth
factor (HGF)/MET inhibitors and other drugs may play an important role in
inhibiting and reversing drug resistance. Alterations in c-MET, a tyrosine kinase receptor encoded by the MET gene, have
been reported in approximately 3% of non-small cell lung cancer (NSCLC) cases
and carry important treatment implications. The best studied genetic alterations
are exon 14 skipping and gene amplification; however, gene rearrangement has
also been described, and multiple fusion partners have been reported. Recently,
in METex14-mutated NSCLC, multitarget tyrosine kinase inhibitors (TKIs), such as
crizotinib and cabozantinib, as well as MET-selective TKIs, such as tepotinib
and capmatinib, have demonstrated durable responses. In this study, we present
the case of a 41-year-old woman with advanced NSCLC harboring an HLA-DRB1-MET
gene fusion. The patient was offered successively two different MET multikinase
inhibitors, crizotinib and cabozantinib, and the selective inhibitor tepotinib.
Each time, including under tepotinib, the patient experienced rapid and complete
responses associated with a tremendous improvement in her physical function. KEY
POINTS: To our knowledge, this is the first report of a patient with non-small
cell lung cancer harboring an HLA-DRB1-MET gene fusion demonstrating a clinical
response to multiple MET inhibitors, including tepotinib. This finding
illustrates the efficacy and rationale to targeting MET regardless of fusion
partner and gives insight to pooling of patients with different MET fusion
products in trials assessing safety and efficacy of novel molecules. Tepotinib is an oral MET inhibitor approved for metastatic non-small cell lung
cancer (NSCLC) harboring MET exon 14 (METex14) skipping mutations. Examining
treatment-naive or tepotinib-resistant cells with MET amplification or METex14
skipping mutations identifies other receptor tyrosine kinases (RTKs) that
co-exist in cells prior to tepotinib exposure and become more prominent upon
tepotinib resistance. In a small cohort of patients with lung cancer with MET
genetic alterations treated with tepotinib, gene copy number gains of other RTKs
were found at baseline and affected treatment outcome. An Src homology 2
domain-containing phosphatase 2 (SHP2) inhibitor delayed the emergence of
tepotinib resistance and synergized with tepotinib in treatment-naive and
tepotinib-resistant cells as well as in xenograft models. Alternative signaling
pathways potentially diminish the effect of tepotinib monotherapy, and the
combination of tepotinib with an SHP2 inhibitor enables the control of tumor
growth in cells with MET genetic alterations. Tyrosine kinase inhibitors (TKIs) have transformed the standard of care in lung
cancer. A number of TKIs have been discovered that specifically target
oncogenes, including MET receptor tyrosine kinase. Second-generation MET TKIs
are showing improved efficacy over first-generation TKIs. Herein, we report a
case of a patient with metastatic lung adenocarcinoma harboring a MET exon 14
splice site mutation who has had prolonged disease control by a
second-generation MET-TKI tepotinib. A 66-yr-old man was diagnosed with stage IV
lung adenocarcinoma. He was started on carboplatin, paclitaxel, and bevacizumab,
but had severe toxicity. He was switched to pembrolizumab as his tumor was PD-L1
70%, and molecular testing was not yet performed because of insufficient tissue.
A bronchoscopy with endobronchial ultrasound was performed and a MET exon 14
splice site mutation was detected by next-generation sequencing. Upon
progression, he was then enrolled in a clinical trial of tepotinib and continues
with stable disease for more than 45 cycles and 31 mo. The MET receptor tyrosine
kinase and the ligand hepatocyte growth factor (HGF) have been implicated as
oncogenes and drivers of non-small-cell lung cancer (NSCLC). Newer MET TKIs
including capmatinib and tepotinib more recently showed not only improved
localized control and response, but early data suggests intracranial activity as
compared to first-generation MET TKIs, both in the front-line and the refractory
setting. This is a case report demonstrating an effective duration of response
in a patient with widely metastatic lung adenocarcinoma harboring a MET exon 14
mutation. Conflict of interest statement: W.X. and P.G. are employed by Merck Institute of
Pharmacometrics, Lausanne, Switzerland (an affiliate of Merck KGaA, Darmstadt,
Germany). M.F.‐H., A.J., C.S., M.K., and S.E.B. are employed by Merck KGaA,
Darmstadt, Germany. G.S.F. has received royalties from Wolters Kluwer; travel
reimbursement from Bristol‐Myers Squibb, EMD Serono, Fujifilm, Millennium
Pharmaceuticals, and Sarah Cannon Research Institute; honoraria from Total
Health Conferencing and Rocky Mountain Oncology Society; and been an advisor for
Fujifilm and EMD Serono. G.S.F. has been an investigator on clinical trials for
which his institution has received funding from: 3‐V Biosciences, Abbisko,
AbbVie, ADC Therapeutics, Aileron Therapeutics, American Society of Clinical
Oncology, Amgen, ARMO BioSciences, AstraZeneca, BeiGene, BioAtla, Biothera
Pharmaceuticals, Celldex Therapeutics, Celgene, Ciclomed, Curegenix, Curis,
Cyteir, Daiichi, DelMar Pharmaceuticals, eFFECTOR Therapeutics, Eli Lilly, EMD
Serono, Epizyme, Exelixis, Fujifilm, Genmab, GlaxoSmithKline, Hutchison
MediPharma, Ignyta, Incyte, Jacobio Pharmaceuticals, Jounce Therapeutics,
Kolltan Pharmaceuticals, Loxo Oncology, MedImmune, Millennium Pharmaceuticals,
Merck KGaA, miRNA Therapeutics, National Institutes of Health, Novartis, OncoMed
Pharmaceuticals, Oncorus, Oncothyreon, Poseida, Precision Oncology, Prelude,
Regeneron Pharmaceuticals, Rgenix, Ribon, Strategia Therapeutics, Syndax
Pharmaceuticals, Taiho Pharmaceutical, Takeda, Tarveda Therapeutics, Tesaro,
Tocagen, Turning Point Therapeutics, University of Texas MD Anderson Cancer
Center, Vegenics, and Xencor. D.S.H. has received research funding from AbbVie,
Adaptimmune, Amgen, AstraZeneca, Bayer, BMS, Daiichi‐Sankyo, Eisai, Eli Lilly,
Fate Therapeutics, Genentech, Genmab, Ignyta, Infinity Pharmaceuticals, Kite
Pharma, Kyowa Kirin, Loxo Oncology, Merck KGaA, MedImmune, Mirati Therapeutics,
miRNA Therapeutics, Molecular Templates, Mologen, NCI‐CTEP, Novartis, Pfizer,
Seattle Genetics, and Takeda; travel reimbursement from AACR, ASCO, Genmab, Loxo
Oncology, miRNA Therapeutics, and SITC. D.S.H. has been an advisor or consultant
to Alpha Insights, Amgen, Axiom Pharmaceuticals, Adaptimmune Therapeutics,
Baxter International, Bayer Healthcare, Genentech, GLG Pharma, Group H,
Guidepoint, Infinity Pharmaceuticals, Janssen, Merrimack Pharmaceuticals,
Medscape, Numab, Pfizer, Prime Oncology, Seattle Genetics, Takeda, Trieza
Therapeutics, WebMD; and has ownership interests in Molecular Match,
OncoResponse, and Presagia Inc. Author information:
(1)Department of Pharmaceutical Sciences, College of Pharmacy and Health
Sciences, St. John's University, Queens, New York, USA.
(2)Department of Pharmaceutical Sciences, College of Pharmacy and Health
Sciences, St. John's University, Queens, New York, USA and Department of
Otolaryngology-Head and Neck Surgery, Zhong Hospital of Wuhan University,
Wuhan, China.
(3)Key Laboratory of Medical Electrophysiology of Education Ministry, School of
Pharmacy, Southwest Medical University, China and Shenzhen Public Service
Platform on Tumor Precision Medicine and Molecular Diagnosis, Southern
University of Science and Technology, Shenzhen, Guangdong, China.
(4)Cell Research Center, Shenzhen Bolun Institute of Biotechnology, Shenzhen,
China.
(5)Key Laboratory of Medical Electrophysiology of Education Ministry, School of
Pharmacy, Southwest Medical University, China and Shenzhen Public Service
Platform on Tumor Precision Medicine and Molecular Diagnosis, Southern
University of Science and Technology, Shenzhen, Guangdong, China.
zouchang.cuhk@gmail.
(6)Department of Pharmaceutical Sciences, College of Pharmacy and Health
Sciences, St. John's University, Queens, New York, USA. [email protected]. BACKGROUND: MET exon 14 skipping is an oncogenic driver occurring in 3-4% of
non-small cell lung cancer (NSCLC). The MET inhibitor tepotinib has demonstrated
clinical efficacy in patients with MET exon 14 skipping NSCLC. Here, we present
data from Japanese patients in the Phase II VISION study, evaluating the
efficacy and safety of tepotinib.
METHODS: In the open-label, single-arm, Phase II VISION study, patients with
advanced/metastatic NSCLC with MET exon 14 skipping received oral tepotinib
500 mg once daily. The primary endpoint was objective response by independent
review. Subgroup analyses of Japanese patients were preplanned.
RESULTS: As of 1 January 2020, 19 Japanese patients received tepotinib and were
evaluated for safety, 15 of whom had ≥9 months' follow-up and were also analysed
for efficacy. By independent review, objective response rate (ORR) was 60.0%
(95% confidence interval [CI]: 32.3, 83.7), median duration of response was not
reached (95% CI: 6.9, not estimable [ne]), and progression-free survival was
11.0 months (95% CI: 1.4, ne). ORR in patients with MET exon 14 skipping
identified by liquid biopsy (n = 8) was 87.5% (95% CI: 47.3, 99.7), and by
tissue biopsy (n = 12) was 50.0% (95% CI: 21.1, 78.9). Patients' quality of life
was maintained with tepotinib treatment. Among patients evaluated for safety,
the most common treatment-related adverse events (any grade) were blood
creatinine increase and peripheral oedema (12 and nine patients, respectively).
CONCLUSIONS: Tepotinib demonstrated robust and durable clinical efficacy in
Japanese patients with advanced NSCLC harbouring MET exon 14 skipping,
identified by either liquid or tissue biopsy. The main adverse events, blood
creatinine increase and peripheral oedema, were manageable. MET exon 14 skipping mutation (MET∆ex14) is present about 3% of non-small cell
lung cancers (NSCLCs). NSCLC patients with MET∆ex14 are characterized by an
average age of over 70 years at diagnosis, a smoking history and a higher
frequency in pleomorphic carcinoma and adenosquamous cell carcinoma than in
adenocarcinoma. It has also been reported that NSCLCs with MET∆ex14 often have
codriver alterations such as EGFR amplification (6-28%), FGFR1 alterations
(5-17%), KRAS alterations (~8%), BRAF alterations (~21%), or PIK3CA
mutation/amplification (~14%). In 2020, the approval of two MET-tyrosine kinase
inhibitors (TKIs), capmatinib and tepotinib, for NSCLCs carrying MET∆ex14 dawned
a new era for MET-targeted therapy. These drugs yielded progression-free
survival of 5.4-12.4 months in clinical trials; however, it has also been
reported that one-third to half of patients show inherent resistance to
MET-TKIs. In addition, the emergence of acquired resistance to MET-TKIs is
inevitable. In this review, we summarize the clinical and molecular
characteristics of NSCLCs with MET∆ex14, the efficacy and safety of capmatinib
and tepotinib, the inherent and acquired resistance mechanisms to MET-TKIs, and
new treatment strategies for NSCLCs with MET∆ex14 in the near future. Recently approved and highly specific small-molecule inhibitors of c-MET exon 14
skipping mutations (e.g., capmatinib, tepotinib) are a new and important
therapeutic option for the treatment of non-small cell lung cancer (NSCLC)
patients harbouring c-MET alterations. Several experimental studies have
provided compelling evidence that c-MET is involved in the regulation of the
immune response by up-regulating inhibitory molecules (e.g., PD-L1) and
down-regulating of immune stimulators (e.g., CD137, CD252, CD70, etc.). In
addition, c-MET was found to be implicated in the regulation of the inflamed
tumour microenvironment (TME) and thereby contributing to an increased immune
escape of tumour cells from T cell killing. Moreover, it is a major resistance
mechanism following treatment of epidermal growth factor receptor mutations
(EGFRmut) with tyrosine kinase receptor inhibitors (TKIs). In line with these
findings c-MET alterations have also been shown to be associated with a worse
clinical outcome and a poorer prognosis in NSCLC patients. However, the
underlying mechanisms for these experimental observations are neither fully
evaluated nor conclusive, but clearly multifactorial and most likely
tumour-specific. In this regard the clinical efficacy of checkpoint inhibitors
(CPIs) and TKIs against EGFRmut in NSCLC patients harbouring c-MET alterations
is also not yet established, and further research will certainly provide some
guidance as to optimally utilise CPIs and c-MET inhibitors in the future. |
List second messengers. | Cyclic adenosine monophosphate
Ceramide
Cyclic diguanylate
Nitric oxide
Calcium
Diacylglycerol | -20pt?>Mycobacterium tuberculosis (Mtb) is a pathogenic bacterium that causes
contagious tuberculosis (TB). Recently, Mtb-secreted proteins have been
considered virulence factors and candidates for drugs and vaccines. Among these
proteins, 6-kDa early secreted antigenic target (ESAT-6) is known to be able to
induce component of matrix metalloproteinase-9 (MMP-9) in epithelial cells,
leading to recruitment of macrophages. However, detailed function of ESAT-6
during macrophage recruitment to inflammatory sites remains unknown. Thus, the
objective of the present study was to elucidate such function of EAST-6 and
mechanism(s) involved. In the present study, we have found that recombit
ESAT-6 purified in the form of ESAT-6 double-connected structure (2E6D) could
inhibit lipopolysaccharide (LPS)-induced potential of cell migration and
inflammation in murine macrophage cells. Interestingly, 2E6D suppressed
LPS-induced MMP-9 expression at both protein and mRNA levels as well as its
enzyme activity. Levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide
synthase (iNOS) enzymes as known upregulators of MMP-9 were significantly
decreased when 2E6D has been treated. In addition, nitric oxide (NO) as a second
messenger was also significantly decreased by treatment with the purified 2E6D.
Furthermore, 2E6D inhibited LPS-induced phosphorylation of IκB and translocation
of NF-κB. Moreover, 2E6D suppressed phosphorylation of MAPK signaling proteins.
Taken together, these results suggest that ESAT-6 can suppress LPS-induced MMP-9
and inflammation by downregulating COX-2, iNOS, and NO through NF-κB and MAPK
signaling. The widespread bacterial second messenger cyclic diguanylate (c-di-GMP)
regulates a variety of processes, including protein secretion, motility, cell
development, and biofilm formation. c-di-GMP-dependent responses are often
mediated by its binding to the cytoplasmic receptors that contain the PilZ
domain. Here, we present comparative structural and sequence analysis of various
PilZ-related domains and describe three principal types of them: (i) the
canonical PilZ domain, whose structure includes a six-stranded beta-barrel and a
C-terminal alpha helix, (ii) an atypical PilZ domain that contains two extra
alpha helices and forms stable tetramers, and (iii) divergent PilZ-related
domains, which include the eponymous PilZ protein and PilZN (YcgR_N) and PilZNR
(YcgR_2) domains. We refine the second c-di-GMP binding motif of PilZ as
[D/N]hSXXG and show that the hydrophobic residue h of this motif interacts with
a cluster of conserved hydrophobic residues, helping maintain the PilZ domain
fold. We describe several novel PilZN-type domains that are fused to the
canonical PilZ domains in specific taxa, such as spirochetes, actinobacteria,
aquificae, cellulose-degrading clostridia, and deltaproteobacteria. We propose
that the evolution of the three major groups of PilZ domains included (i) fusion
of pilZ with other genes, which produced Alg44, cellulose synthase, and other
multidomain proteins; (ii) insertion of an ∼200-bp fragment, which resulted in
the formation of tetramer-forming PilZ proteins; and (iii) tandem duplication of
pilZ genes, which led to the formation of PilZ dimers and YcgR-like
proteins.IMPORTANCE c-di-GMP is a ubiquitous bacterial second messenger that
regulates motility, biofilm formation, and virulence of many bacterial
pathogens. The PilZ domain is a widespread c-di-GMP receptor that binds c-di-GMP
through its RXXXR and [D/N]hSXXG motifs; some PilZ domains lack these motifs and
are unable to bind c-di-GMP. We used structural and sequence analysis to assess
the diversity of PilZ-related domains and define their common features. We show
that the hydrophobic residue h in the second position of the second motif is
highly conserved; it may serve as a readout for c-di-GMP binding. We describe
three principal classes of PilZ-related domains, canonical, tetramer-forming,
and divergent PilZ domains, and propose the evolutionary pathways that led to
the emergence of these PilZ types. The second messenger calcium plays a key role in conveying specificity of
signaling pathways in plant cells. Specific calcium signatures are decoded to
generate correct gene expression responses and amplification of calcium
signatures is vital to this process. (1) It is not known if this amplification
is an intrinsic property of all calcium-regulated gene expression responses and
whether all calcium signatures have the potential to be amplified, or (2) how a
given calcium signature maintains specificity in cells containing a great number
of transcription factors (TFs) and other proteins with the potential to be
calcium-regulated. The work presented here uncovers the design principle by
which it is possible to decode calcium signals into specific changes in gene
transcription in plant cells. Regarding the first question, we found that the
binding mechanism between protein components possesses an intrinsic property
that will nonlinearly amplify any calcium signal. This nonlinear amplification
allows plant cells to effectively distinguish the kinetics of different calcium
signatures to produce specific and appropriate changes in gene expression.
Regarding the second question, we found that the large number of calmodulin
(CaM)-binding TFs or proteins in plant cells form a buffering system such that
the concentration of an active CaM-binding TF is insensitive to the
concentration of any other CaM-binding protein, thus maintaining specificity.
The design principle revealed by this work can be used to explain how any
CaM-binding TF decodes calcium signals to generate specific gene expression
responses in plant cells via transcription. Adenylyl cyclases (ACs), which are responsible for catalyzing the conversion of
adenosine triphosphate (ATP) into the second messenger cyclic adenosine
monophosphate (cAMP), play a critical role in cell signal transduction. In this
study, a combined approach involving docking-based virtual screening, with the
combination of homology modeling followed by an in-vitro, and cell-based
biological assay have been performed for discovering a class of novel potent and
selective isoform adenylyl cyclase type 8 (AC8) agonist. The computer-aided
virtual screening was used to identify fourteen virtual cluster compounds as
potential hits which were further subjected to rigorous bioassays. A novel hit
compound VHC-7 (ethyl 3-(2,4-dichlorobenzyl)-2-oxoindoline-3-carboxylate) was
identified as a highly potent selective AC8 agonist with EC50 value of
0.1052 ± 0.038 µM. Remarkably, the molecule herein reported can be explored
further to discover greater number of hit compounds with better pharmacokinetic
properties as well as to serve as a promising novel hit agonist of AC8 for the
treatment of various central nervous system disorders and its associated
diseases. LuxR-type regulators play important roles in transcriptional regulation in
bacteria and control various biological processes. A genome sequence analysis
showed the existence of seven LuxR-type regulators in Azorhizobium caulinodans
ORS571, an important nitrogen-fixing bacterium in both its free-living state and
in symbiosis with its host, Sesbania rostrata. However, the functional
mechanisms of these regulators remain unclear. In this study, we identified a
LuxR-type regulator that contains a cheY-homologous receiver (REC) domain in its
N terminus and designated it AclR1. Interestingly, phylogenetic analysis
revealed that AclR1 exhibited relatively close evolutionary relationships with
MalT/GerE/FixJ/NarL family proteins. Functional analysis of an aclR1 deletion
mutant (ΔaclR1) in the free-living state showed that AclR1 positively regulated
cell motility and flocculation but negatively regulated exopolysaccharide
production, biofilm formation, and second messenger cyclic diguanylate
(c-di-GMP)-related gene expression. In the symbiotic state, the ΔaclR1 mutant
was defective in competitive colonization and nodulation on host plants. These
results suggested that AclR1 could provide bacteria with the ability to compete
effectively for symbiotic nodulation. Overall, our results show that the
REC-LuxR-type regulator AclR1 regulates numerous phenotypes both in the
free-living state and during host plant symbiosis. BACKGROUND: Pain is one of the most common clinical symptoms . This review aims
to describe research on herbs and their active ingredients in treating pain and
provide a valuable reference for the development and utilization of analgesic
traditional Chinese medicine (TCM).
MATERIAL AND METHODS: The literature search was performed from 1995 to October
2016, covering the relevant studies that concern the treatment of pain with TCM.
Active ingredients extracted from TCM with analgesic activity are summarized and
classified into six categories, including polysaccharides, saponins, alkaloids,
flavonoids, terpenoids, and other constituents.
RESULTS: There are two pathways constituting the analgesic mechanisms of TCM:
through the central nervous system and the peripheral nervous system. The former
pathway includes increasing the content of endogenous analgesic substances like
opiate peptide, cutting down the second messenger of neurotransmitter like
nitric oxide (NO), reducing the content of prostaglandin E2 (PGE2) in brain
tissues, blocking the central calcium channel, reducing excitatory amino acids
in brain tissues, inhibiting their receptors and raising the content of the
central 5-hydroxytryptamine (5-HT). The latter one usually involves the decrease
in the secretion of peripheral algogenic substances, the induction of
pain-sensitive substances, the accumulation of a local algogenic substance, the
increase in the release of peripheral endogenous analgesia materials and the
regulation of c-Fos gene (immediate early gene). Cyclic adenosine monophosphate (cAMP) is a second messenger involved in the
dental regeneration. However, efficient long-lasting delivery of cAMP that is
sufficient to mimic the in vivo microenvironment remains a major challenge.
Here, cAMP was loaded in stem cells from apical papilla (SCAPs) using
layer-by-layer self-assembly with gelatin and alginate polyelectrolytes
(LBL-cAMP-SCAPs). LBL-cAMP-SCAPs expressed cAMP and increased the
phosphorylation level of cAMP-response element-binding protein (CREB) which were
evaluated by immunofluorescence and western blotting (WB). Enzyme-linked
immunosorbent assay (ELISA) demonstrated that a sustained release of cAMP and
vascular endothelial growth factor (VEGF) were present up to 14 days. Scanning
electron microscopy (SEM) found LBL-coated SCAPs exhibited a spheroid-like
morphology. CCK8 and live/dead staining showed that LBL treatment had no
significant effect on cell proliferation and viability. LBL-cAMP-SCAPs enhanced
mineralized nodule formation and up-regulated the mRNA levels of the
osteogenesis-related genes, as well as related transcription factor-2 protein
level which were revealed by Alizarin red staining, RT-PCR and WB, respectively.
In conclusion, LBL self-assembly loaded with cAMP promoted the osteo/odontogenic
differentiation of SCAPs, thereby providing a potential strategy for bioactive
molecular delivery in dental regeneration. The prevailing mechanism of action of chemotherapeutic drugs has been challenged
by the role of ceramide, a second messenger, shown to induce apoptosis,
differentiation, growth arrest, senescence, and autophagy in different cells
(Chabner BA, Roberts TG Jr, Nat Rev Cancer 5:65-72, 2005; Jacobi J et al, Cell
Signal 29:52-61, 2017; Rotolo J et al, J Clin Invest 122:1786-1790, 2012; Truman
JP et al, PLoS One 5:e12310, 2010). Certain chemotherapeutic drugs activate the
acid sphingomyelinase (ASMase)/ceramide pathway, generating ceramide in the
tumor endothelium and this microvascular dysfunction is crucial for the tumor
response. Ceramide has fusigenic properties and as such, when generated within
the plasma membrane, initiates the oligomerization of ceramide-and
cholesterol-rich domains in the outer leaflet of the plasma membrane, leading to
the formation of ceramide-rich microdomains/platforms (CRP) (Jacobi J et al,
Cell Signal 29:52-61, 2017; Truman JP et al, PLoS One 5:e12310, 2010; van Hell
AJ et al, Cell Signal 34:86-91, 2017; Hajj C, Haimovitz-Friedman A, Handb Exp
Pharmacol 216:115-130, 2013) known as "signaling platform." This chapter will
discuss the generation, detection, and quantitation of CRP and their possible
modulation in endothelial cells, in vitro and in vivo in response to certain
chemotherapeutic drugs. |
Is there a genetic cause of craniostenosis? | 9There a a number of different genetic mutations or syndromes(Saethre-Chotzen, Aperts, Crouzon, Pfeiffer) associated with craniostenosis. | A 3-year-old child with tertiary trisomy (14 (+14q--), daughter of a mother with
a balanced reciprocal translocation [46,XX,t(14;16)(q11;q24) is presented.
Craniostenosis and developmental retardation were the primary presenting
features in this patient. Result of a family study based on 584 patients with craniostenosis brings some
answers useful for genetic counselling. For 98 patients (15%) a syndrome is
associated. Third part of them has Apert syndrome, an other third part has
Crouzon syndrome, and for the last third more exceptional acrocephalosyndactyly
syndrome (Saethre-Chotzen, Pfeiffer) or others atypical associations, sometimes
not yet described, but with an autosomal domit inheritance. Non syndromic
craniostenosis involves differently according to the type of join, but the
localization is the same if recurrence will be happen. Coronal craniostenosis
seems to be a domit autosomal character, when scaphocephaly is more often
sporadic; for both, an autosomal domit inheritance is not excluded for some
pedigrees. If the recurrence risk exist in some cases, it is generally well
accepted by parents on account of the good neurosurgeon prognosis. A suckling baby with microcephaly, craniostenosis, downward slanting palpebral
fissues, malformed ears, cerebral, cardiac and intestinal malformation, and
partial 6q25 leads to 6qter trisomy is presented. The baby is the second child
of a mother with balanced translocation : 46,XX,t(2;6)(q37,q25). The first child
with a similar phenotype and cardiac malformation did not undergo cytogenetic
investigation and died at 4 months. Saethre-Chotzen syndrome is an autosomal domit disease characterized by
craniosynostosis, ptosis, and limb and external ear abnormalities. Variable
expressivity is a well-known phenomenon in this disorder. A large Indian family
has been recently identified as carrying a nonsense TWIST mutation (Q28 X) in 17
members, of whom 16 were examined in detail. Only 4 (25%) of the patients showed
patent craniostenosis, namely, oxycephaly. The penetrance of craniosynostosis in
this family is lower than previously reported in the literature. Fifteen
patients (93%) had moderate to severe ptosis. Minor limb and external ear
abnormalities were present in most patients. Eyelid features were the hallmark
of the disease for 12 members of the family, suggesting that mutations in TWIST
may lead to a phenotype with mainly palpebral features and no craniostenosis.
The clinical analysis of this large family clearly illustrates the significant
variable expressivity, probably related to haploinsufficiency because of the
TWIST mutation. This phenotypic variability remains unclear but could be the
result of modifier genes and/or genetic background effect, as noticed previously
in the transgenic twist-null heterozygous mice. BACKGROUND: Since its first description by Virchow, the principle of abnormal
skull growth due to restriction of skull growth at the fused sutures, and the
realisation by Moss that the sutures at the skull base are equally affected,
have been the main intellectual driving forces behind the majority of cranial
expansion procedures performed currently in children with craniosynostosis.
CURRENT OBSERVATIONS: Despite original impressions that craniosynostosis leads
to craniostenosis, many studies have demonstrated that in the majority of
patients with craniosynostosis there is normal skull volume in those over the
age of 6 months. In Apert syndrome, skull volume is invariably larger than
normal. Some studies have shown that intracranial pressure is independent of
intracranial volume, and can exist in the presence of normal volume, or indeed
after cranial expansion. These observations imply that cranial expansion
procedures create a state of artificially increased skull volume, in the quest
to improve appearance and function.
FUTURE ADVANCES: This creates a new angle of view through which skull growth
abnormalities are seen. It is becoming clearer that in most patients with
craniosynostosis, there is regional imbalance of skull growth, which co-exists
with a variety of other equally important factors, such as genetic defects,
raised intracranial pressure, venous hypertension, and other brain parenchymal
anomalies such as hindbrain hernia or hydrocephalus. It is becoming increasingly
obvious that the type of surgical treatment currently practised in most cases is
conceptually incorrect. Recent modifications such as the use of springs or
distraction do not escape from the underlying philosophy of cranial expansion.
With that in mind, it is hoped that advances in the fields of genetics and
molecular biology will provide treatments for the cause of craniosynostosis
rather than the symptomatic relief that surgery offers currently.
CONCLUSION: Until then, there is a need to develop better ways of quantifying
regional abnormalities of skull growth. Apert syndrome - acrocephalosyndactyly - is a rare autosomal domit disorder
representing 1:65 000 cases of living newborns. Characteristic malformations of
the Apert syndrome are early craniostenosis, microviscerocranium and II-V finger
syndactyly of hand and toes with proximal phalanx of the bilateral thumb "in
delta". It is difficult to determine prenatal diagnosis in the second quarter,
when examining the morphology of fetal signs; the dysmorphism signs appeared in
the third pregcy quarter. We present here the case of a newborn with Apert
syndrome that was born prematurely in our Clinic after a monitored pregcy,
where there was issued a suspicion of cranio-facial dysmorphism, malposition and
malformation of the feet and hands in the third quarter of prenatal pregcy.
The diagnosis of Apert syndrome was placed on clinical signs, laboratory and
genetic tests. The clinical outcome of the baby in the maternity was favorable,
the therapeutic management being established by a multidisciplinary team.
Immediate complications were due to the case of prematurity: respiratory
distress syndrome and the characteristics of the syndrome: micrognathia and
naso-facial dysmorphism, syndactyly, bilateral foot metatarsus adductus. Syndromic craniosynostosis is a group of multiple conditions with high
heterogeneity, and many rare syndromes still remain to be characterized. To
identify and analyze causative genetic variants in nine unrelated probands
mainly manifested as syndromic craniosynostosis, we reviewed the relevant
medical information of the patients and performed the whole exome sequencing,
further verified with Sanger sequencing and parental background. Bioinformatics
analysis was used to evaluate the potential deleterious or benign effect of each
genetic variant through evolutionary conservation alignment, multi-lines of
computer predication and the allele frequency in population dataset (control and
patient). The Standards and guidelines from American College of Medical Genetics
and Genomics was used to classify and interpret the pathogenicity for each
genetic variant. All the nine probands were found to carry the possibly
causative variants, among which three variants including two missense mutations
(c.3385C>T in IFT122 gene, c.3581A>G in SMC1A gene) and a frameshift mutation
(c.434dupA in TWIST1 gene) have never been reported in patients before. We
suggested Cornelia de Lange syndrome caused by SMC1A variant is a neglected
syndromic craniosynostosis. Our study not only expanded genotypic and phenotypic
spectrum of the rare syndromes, but also confirmed that there existed an
underlying genetic mechanism. We emphasized that deliberate selection of both
the potential candidates and comprehensive detection methods for genetic
analysis is important to increase the genetic diagnosis yield of syndromic
craninosynostosis. Occurring once in every 2000 live births, craniosynostosis is one of the most
frequent congenital anomalies encountered by the craniofacial surgeon. Syndromic
craniosynostoses account for approximately 15 percent of cases and demonstrate
Mendelian patterns of inheritance with well-established genetic causes; however,
nonsyndromic craniosynostoses, which account for approximately 85 percent of
cases, are genetically heterogeneous and largely unexplored. Nonsyndromic
craniosynostosis is sporadic in more than 95 percent of affected families; thus,
surgeons have suggested for decades that nonsyndromic craniosynostosis is likely
a fluke occurrence. Contrary to this, recent studies have established that
genetics underlie a substantial fraction of nonsyndromic craniosynostosis risk.
Given the predomitly sporadic occurrence of disease, parents are often
bewildered by the primary occurrence of nonsyndromic craniosynostosis or even
recurrence in their own families and request genetic testing. Existing genetic
testing panels are useful when the phenotype strongly resembles a known
syndrome, wherein the risk of disease recurrence can be accurately predicted for
future offspring of the parents and the future offspring of the affected child.
The diagnostic utility of existing panels for nonsyndromic craniosynostosis,
however, is extremely low, and these tests are quite costly. Recent genetic
studies have identified several novel genes and pathways that cause nonsyndromic
craniosynostosis, providing genetic evidence linking the causes of syndromic and
nonsyndromic craniosynostoses, and allowing for genotype-based prediction of
risk of recurrence in some nonsyndromic families. Based on analysis of exome
sequence data from 384 families, the authors provide recommendations for a new
genetic testing protocol for children with nonsyndromic craniosynostosis, which
include testing nonsyndromic cases of sagittal, metopic, and coronal
craniosynostosis. |
Can bergapten cross the blood-brain barrier? | Yes, bergapten can cross the blood-brain barrier. | Bergapten is a natural furocoumarin, also known as 5-methoxypsoralen, and its
medicinal value has been paid more and more attention. By sorting out the
pharmacological literature of bergapten, we found that bergapten has a wide
range of pharmacological effects, including neuroprotection, organ protection,
anticancer, antiinflammatory, antimicrobial, and antidiabetes effects.
However，bergapten has complex impacts on the hepatic metabolic enzyme. Moreover,
pharmacokinetic studies showed that bergapten has higher absolute
bioavailability and can cross the blood-brain barrier and has a great potential
for treating brain disease, but the mechanism needs further clarification to
make greater use of its ability to treat brain diseases. Furthermore, the
phototoxicity of bergapten combined with ultraviolet light has always been
mentioned. In view of its wide range of pharmacological activities, bergapten is
expected to be a potential drug candidate for the treatment of diabetes and
diabetes-induced osteoporosis, epilepsy, Alzheimer's disease, depression, and
cancer. However, further studies are needed to elucidate its molecular
mechanisms and targets. The phototoxicity of bergapten as a side effect should
be further avoided. On the other hand, the photoactivation of bergapten in the
anticancer aspect can be better utilized. |
Does TIMELESS-TIPIN participate in replisome disassembly? | Yes. TIMELESS-TIPIN and UBXN-3 promote replisome disassembly during DNA replication termination in Caenorhabditis elegans. | The eukaryotic replisome is rapidly disassembled during DNA replication
termination. In metazoa, the cullin-RING ubiquitin ligase CUL-2LRR-1 drives
ubiquitylation of the CMG helicase, leading to replisome disassembly by the
p97/CDC-48 "unfoldase". Here, we combine in vitro reconstitution with in vivo
studies in Caenorhabditis elegans embryos, to show that the replisome-associated
TIMELESS-TIPIN complex is required for CUL-2LRR-1 recruitment and efficient CMG
helicase ubiquitylation. Aided by TIMELESS-TIPIN, CUL-2LRR-1 directs a suite of
ubiquitylation enzymes to ubiquitylate the MCM-7 subunit of CMG. Subsequently,
the UBXN-3 adaptor protein directly stimulates the disassembly of ubiquitylated
CMG by CDC-48_UFD-1_NPL-4. We show that UBXN-3 is important in vivo for
replisome disassembly in the absence of TIMELESS-TIPIN. Correspondingly,
co-depletion of UBXN-3 and TIMELESS causes profound synthetic lethality. Since
the human orthologue of UBXN-3, FAF1, is a candidate tumour suppressor, these
findings suggest that manipulation of CMG disassembly might be applicable to
future strategies for treating human cancer. |
Nemolizumab has been shown to be effective for which disease? | Nemolizumab has been shown to be effective for atopic dermatitis. | BACKGROUND: Interleukin-31 may play a role in the pathobiologic mechanism of
atopic dermatitis and pruritus. We wanted to assess the efficacy and safety of
nemolizumab (CIM331), a humanized antibody against interleukin-31 receptor A, in
the treatment of atopic dermatitis.
METHODS: In this phase 2, randomized, double-blind, placebo-controlled, 12-week
trial, we assigned adults with moderate-to-severe atopic dermatitis that was
inadequately controlled by topical treatments to receive subcutaneous
nemolizumab (at a dose of 0.1 mg, 0.5 mg, or 2.0 mg per kilogram of body weight)
or placebo every 4 weeks or an exploratory dose of 2.0 mg of nemolizumab per
kilogram every 8 weeks. The primary end point was the percentage improvement
from baseline in the score on the pruritus visual-analogue scale (on which a
negative change indicates improvement) at week 12. Secondary end points included
changes in the score on the Eczema Area and Severity Index (EASI, on which a
negative change indicates improvement), and body-surface area of atopic
dermatitis.
RESULTS: Of 264 patients who underwent randomization, 216 (82%) completed the
study. At week 12, among the patients who received nemolizumab every 4 weeks,
changes on the pruritus visual-analogue scale were -43.7% in the 0.1-mg group,
-59.8% in the 0.5-mg group, and -63.1% in the 2.0-mg group, versus -20.9% in the
placebo group (P<0.01 for all comparisons). Changes on the EASI were -23.0%,
-42.3%, and -40.9%, respectively, in the nemolizumab groups, versus -26.6% in
the placebo group. Respective changes in body-surface area affected by atopic
dermatitis were -7.5%, -20.0%, and -19.4% with nemolizumab, versus -15.7% with
placebo. Among the patients receiving nemolizumab every 4 weeks, treatment
discontinuations occurred in 9 of 53 patients (17%) in the 0.1-mg group, in 9 of
54 (17%) in the 0.5-mg group, and in 7 of 52 (13%) in the 2.0-mg group, versus
in 9 of 53 (17%) in the placebo group.
CONCLUSIONS: In this phase 2 trial, nemolizumab at all monthly doses
significantly improved pruritus in patients with moderate-to-severe atopic
dermatitis, which showed the efficacy of targeting interleukin-31 receptor A.
The limited size and length of the trial preclude conclusions regarding adverse
events. (Funded by Chugai Pharmaceutical; XCIMA ClinicalTrials.gov number,
NCT01986933 .). Biologic medications are recent advances that have clinical significance in the
treatment of moderate-to-severe AD. A systemic literature review was performed
to examine the efficacy and safety of biologic therapies currently in phase II
and phase III of clinical trials for moderate-to-severe AD. Our team searched
the databases, PubMed, Google Scholar, and ClinicalTrials.gov, on September 2019
for studies pertaining to the use of biologic drugs in AD. Key words included
each drug (lebrikizumab, tralokinumab, fezakinumab, etokimab, nemolizumab,
tezepelumab, and GBR 830) or 'biologic drugs' or 'immunotherapies' combined with
'atopic dermatitis.' References within retrieved articles were also reviewed to
identify potentially missed studies. A total of 19 articles were included in
this review. Lebrikizumab, tralokinumab, fezakinumab, nemolizumab, and GBR 830
lead to statistically significant improvements in disease severity and multiple
endpoint outcome scores. Tezepelumab and etokimab, however, did not demonstrate
statistically significant changes in primary outcome endpoints. Further
assessment of tezepelumab and etokimab are needed to assess their safety and
efficacy in patients with moderate-to-severe AD. Tralokinumab, lebrikizumab,
fezakinumab, nemolizumab, and GBR 830 are effective treatment options for adults
with moderate-to-severe AD, but further large-scale studies are needed to
confirm their efficacy as monotherapy in children with moderate-to-severe AD. BACKGROUND: Nemolizumab is a subcutaneously administered humanized monoclonal
antibody against interleukin-31 receptor A, which is involved in pruritus and
inflammation in atopic dermatitis. In phase 2 studies, nemolizumab lessened the
severity of atopic dermatitis.
METHODS: In a 16-week, double-blind, phase 3 trial, we randomly assigned
Japanese patients with atopic dermatitis and moderate-to-severe pruritus and an
inadequate response to topical agents in a 2:1 ratio to receive subcutaneous
nemolizumab (60 mg) or placebo every 4 weeks until week 16, with concomitant
topical agents. The primary end point was the mean percent change in the
visual-analogue scale (VAS) score for pruritus (range, 0 to 100, with higher
scores indicating worse pruritus) from baseline to week 16. Secondary end points
included the time course of change in the VAS score for pruritus up to week 4,
the change in the Eczema Area and Severity Index (EASI) score (range, 0 to 72,
with higher scores indicating greater severity), a score of 4 or less on the
Dermatology Life Quality Index (DLQI; range, 0 to 30, with higher scores
indicating a greater effect on daily life), a score of 7 or less on the Insomnia
Severity Index (ISI; range, 0 to 28, with higher scores indicating greater
severity), and safety.
RESULTS: A total of 143 patients were randomly assigned to receive nemolizumab
and 72 to receive placebo. The median VAS score for pruritus at baseline was 75.
At week 16, the mean percent change in the VAS score was -42.8% in the
nemolizumab group and -21.4% in the placebo group (difference, -21.5 percentage
points; 95% confidence interval, -30.2 to -12.7; P<0.001). The mean percent
change in the EASI score was -45.9% with nemolizumab and -33.2% with placebo.
The percentage of patients with a DLQI score of 4 or less was 40% in the
nemolizumab group and 22% in the placebo group; the percentage of patients with
an ISI score of 7 or less was 55% and 21%, respectively. The incidence of
injection-related reactions was 8% with nemolizumab and 3% with placebo.
CONCLUSIONS: In this 16-week trial, the use of subcutaneous nemolizumab in
addition to topical agents for atopic dermatitis resulted in a greater reduction
in pruritus than placebo plus topical agents. The incidence of injection-site
reactions was greater with nemolizumab than with placebo. Longer and larger
trials are necessary to determine whether nemolizumab has a durable effect and
is safe for atopic dermatitis. (Funded by Maruho; JapicCTI number, 173740.). BACKGROUND: The mainstay of atopic dermatitis treatment has been largely
unchanged over the last few decades. With improved understanding of the
immunologic pathways underlying atopic dermatitis in recent years, targeted
biologic therapies are being developed.
OBJECTIVE: Discuss efficacy and safety profiles of emerging biologics in phase 2
and 3 clinical trials.
METHODS: A systemic literature review was conducted to identify results of
randomized, placebo-controlled trials of monoclonal antibodies up to March 1,
2020 for the treatment of atopic dermatitis.
RESULTS: Targeted biologics appear to have acceptable safety profiles.
Dupilumab, lebrikizumab, and nemolizumab demonstrate efficacy as agents
producing improvement in clinical severity and pruritus.
CONCLUSIONS: The growing class of biologics shows promise in meeting the needs
of treatment-resistant atopic dermatitis. The use of validated core measurements
is necessary for future trials in order to adequately compare agents and
progress evidence-based medicine. Pruritus represents one of the most common symptoms in dermatology and general
medicine. Chronic pruritus severely impairs the quality of life of affected
patients. During the last two decades a number of modulators and mediator of
pruritus have been identified. Recently, Interleukin (IL)-31 and its receptor
complex attracted significant interest, as clinical phase two studies
demonstrated therapeutic efficacy of the neutralizing IL-31 receptor A (IL-31RA)
antibody nemolizumab in patients suffering from atopic dermatitis or prurigo
nodularis. IL-31 has also been shown to play relevant roles in allergic contact
dermatitis, urticaria, mastocytosis, allergic rhinitis and asthma. Here, we
summarize the current knowledge of the novel cytokine IL-31 and its receptor
regarding cellular origin, regulation, signaling pathways and their involvement
in biological processes such as pruritus, neuronal growth, inflammation, barrier
dysfunction and tissue remodeling. BACKGROUND: Nemolizumab is a humanized anti-IL-31 receptor blocker in phase 3
for atopic dermatitis (AD).
OBJECTIVE: Analyse onset of action of nemolizumab 30 mg and compare efficacy and
safety vs placebo (SC q4wk plus loading dose) in moderate-to-severe AD.
METHODS: Post hoc analysis of patients with Eczema Area and Severity Index
(EASI) scores ≥ 16 from a phase 2b trial of moderate-to-severe AD. Endpoints
were change in EASI score at week 16, peak pruritus numeric rating scale
(PP-NRS), Investigator's Global Assessment (IGA), changes in sleep and
responders with ≥ 4-point improvement on PP-NRS.
RESULTS: There was a significantly greater itch relief apparent by Day 2 (-22.8%
vs -12.3% PP-NRS; P = 0.005) which continued to improve through week 16 (-68.5%
vs -30.9% PP-NRS; P < 0.001). At week 16, PP-NRS ≥ 4-point response of itch was
observed in 68.0% nemolizumab vs 15.9% placebo patients (P ≤ 0.001). There was
also a rapid improvement of sleep disturbance with nemolizumab 30 mg, with a
significant separation from placebo by Day 3 (-26.6% vs -9.0%; P < 0.001) which
further improved till week 16 (-76.0% vs -36.5%; P < 0.001). Also for the EASI
score a separation between groups in favour of nemolizumab was observed by week
1 (P ≤ 0.001), which increased through week 16 (-68.6% vs. -42.6%; P = 0.002).
Finally, the degree of response was greater in nemolizumab-treated patients;
clinically relevant reductions of 75% EASI were observed in 50.0% of nemolizumab
patients versus 15.9% of placebo patients, while 90% reductions were reported
for 36.0% and 6.8% of patients, respectively (P < 0.001 for both). IGA success
(score of 0/1) was 32.0% for nemolizumab vs 6.8% for placebo (P = 0.002).
Nemolizumab was safe and well-tolerated in this population; nasopharyngitis and
upper respiratory tract infection were the most common adverse events.
CONCLUSIONS: Nemolizumab resulted in very rapid, sustained improvements of
inflammation, pruritus and sleep in patients with EASI ≥ 16 at baseline. BACKGROUND: Atopic dermatitis (AD) is a widely acquired, relapsing inflammatory
skin disease. Biologics are now widely used in patients with moderate-to-severe
AD.
OBJECTIVE: This work aims to summarize both label and off-label biologics on AD
treatment in phase II and phase III stages, and compile evidence on the efficacy
of the most-studied biologics.
METHODS: We conducted a comprehensive literature search through PubMed, EMBASE,
and ClinicalTrials.gov to identify all documented biological therapies for AD.
The criteria were further refined to focus on those treatments with the highest
evidence level for AD with at least one randomized clinical trial supporting
their use. Only studies or articles published in English were enrolled in this
study.
FINDINGS: Primary searches identified 525 relevant articles and 27 trials.
Duplicated articles and papers without a full text were excluded. Only completed
trials were enrolled. We included 28 randomized controlled trials, 4 unpublished
trials, 2 observational studies, and 1 meta-analysis. Eight kinds of biologics,
including IL-4/IL-13 inhibitors, JAK inhibitors, anti-IL-13 antibodies,
anti-IL-22 antibodies, anti-IL-33 antibodies, thymic stromal lymphopoietin
inhibitor (TSLP), OX40 antibodies, and H4R-antagonists were included in this
work. Dupliumab, as the most widely used and investigated biologic, was reported
in 1 meta-analysis and 4 trials exploring its long-term use and application in
both adults and pediatric patients. Besides dupilumab, four other IL-4/IL-13
inhibitors recruited were all randomized, clinical trials at phase 2-3 stage.
Six different kinds of JAK inhibitors were summarized with strong evidence
revealing their significant therapeutic effects on AD. There were 3 trials for
nemolizumab, an anti-IL-13 antibody, all of which were in the phase 2 clinical
trial stage. Results showed nemolizumab could be another alternative therapy for
moderate-to-severe AD with long-term efficiency and safety.
CONCLUSION: The biological therapies with the most robust evidence on efficacy
and long-term safety for AD treatment include dupilumab, barcitinib,
abrocitinib, and delgocitinib. Most of the biologics mentioned in this review
were still at the exploratory stage. This review will help practitioners advise
patients seeking suitable biological therapies and offer experimental study
directions for treatment. Atopic dermatitis (AD) is a common inflammatory dermatologic disease clinically
characterized by intense itch, recurrent eczematous lesions, and a chronic or
relapsing disease course. Mild-to-moderate AD can be controlled by using
moisturizers and topical immunomodulators such as topical corticosteroids and
calcineurin inhibitors. If topical therapies fail, phototherapy and systemic
immunosuppressant therapies, such as ciclosporin, methotrexate, and
azathioprine, can be considered. However, relapse and side effects could still
occur. The pathogenesis of AD involves epidermal barrier dysfunction, skin
microbiome abnormalities, and cutaneous inflammation. Inflammatory mediators,
such as interleukin (IL)-4, IL-13, IL-31, IL-33, IL-17, IL-23, and thymic
stromal lymphopoietin, are involved in AD development. Therefore, a series of
biological agents targeting these cytokines are promising approaches for
treating AD. Dupilumab is the first biological agent approved for the treatment
of AD in patients aged 6 years and older in the United States. Tralokinumab,
lebrikizumab, and nemolizumab have also been confirmed to have significant
efficacy against AD in phase III or IIb clinical trials. Also, fezakinumab was
effective in severe AD patients in a phase IIa trial. However, phase II trials
of ustekinumab, tezepelumab, etokimab, secukinumab, and omalizumab have failed
to meet their primary endpoints. Phase II trials of GBR 830 and KHK 4083 are
ongoing. In general, further studies are needed to explore new therapeutic
targets and improve the efficacy of biological agents. |
Is hemoglobin antimicrobial? | Yes,
Beyond its physiological activity, hemoglobins are able to inhibit the growth of several microorganisms. | Blood, from slaughterhouses, is an inevitable part of meat production, causing
environmental problems due to the large volumes recovered and its low
valorization. However, the α137-141 peptide, a natural antimicrobial peptide,
can be obtained after hydrolysis of hemoglobin, the main constituent of blood
red part. To recover it at a sufficient concentration for antimicrobial
applications, a new sustainable technology, called electrodialysis with
ultrafiltration membrane (EDUF), was investigated. The α137-141 concentration
was increased about 4-fold at a feed peptide concentration of 8% with an
enrichment factor above 24-fold. This feed peptide concentration also needed the
lowest relative energy consumption. Moreover, this peptide fraction protected
meat against microbial growth, as well as rancidity, during 14 days under
refrigeration. This peptide fraction was validated as a natural preservative and
substitute for synthetic additives against food spoilage. Finally, producing
antimicrobial/antioxidant peptide from wastes by EDUF fits perfectly with the
concept of circular economy. Hemoglobin is one of the most important molecules of the human body. Beyond its
physiological activity, hemoglobins are able to inhibit the growth of several
microorganisms. Since 1999, studies have reported that antimicrobial peptides
can be produced by blood-feeding insects through hemoglobin digestion, and it
has been reported that Triatoma infestans can generate an antimicrobial fragment
from human fibrinopeptide. Thus T. infestans intestinal content was analyzed
through Reverse Phase High-Performance Liquid Chromatography (RP-HPLC), the
eluted fractions were tested against Micrococcus luteus, Escherichia coli and
Staphylococcus aureus, and the active fractions submitted to mass spectrometry.
The data obtained were compared to hemoglobin databases to verify the presence
of hemoglobin-derived fragments. Ten fractions eluted from chromatography
presented antimicrobial activity, and when analyzed through mass spectrometry
revealed the presence of 8 murine hemoglobin α-chain fragments and 24 fragments
from murine hemoglobin β fragments. Through the compilation of the fragments is
possible to obtain over 67% coverage of both sequences. Part of the amino acid
sequences corresponds to the sequences already identified on other intestinal
contents of arthropods, and are highly conserved between the blood of other wild
animals that are the most common intermediate hosts of Chagas' disease in Brazil
and some of the main natural blood source for triatomines. |
What is the mammalian version of arginine vasotocin? | Arginine vasotocin (AVT) is the non-mammalian homolog of arginine vasopressin (AVP) | Nine active neurohypophyseal principles have been isolated and identified among
the vertebrates. Arginine-vasotocin is the most ubiquitous, occurring in
pituitary glands from representatives of all the major vertebrate groups. There
is much more variation in structure among the principles that resemble oxytocin.
The manner in which these evolved remains unclear. Arginine-vasotocin stimulates
smooth muscles from a wide variety of vertebrate species. It can stimulate
contraction of oviducts from many jawed fishes and tetrapods. The oxytocin-like
peptides are usually less active in this respect. Among adult mammals
arginine-vasotocin is replaced by arginine-vasopressin which has much less
oxytocin activity. Thus, although arginine-vasotocin may both stimulate oviducts
and cause water retention in nonmammalian tetrapods, oxytocic and antidiuretic
functions can be regulated independently by oxytocin and vasopressin in mammals.
Arginine-vasotocin elicits vasoconstrictor responses in even the most primitive
vertebrates. These may be systemic or regional. Their distribution may determine
whether arginine-vasotocin acts as a diuretic or an antidiuretic agent. It is
possible that the most primitive neurohypophyseal functions were related to
cardiovascular regulation and that the neurohypophysis acquired its
osmoregulatory functions later in vertebrate evolution. The neuropeptide arginine vasotocin (AVT; non-mammals) and its mammalian
homologue, arginine vasopressin (AVP) influence a variety of sex-typical and
species-specific behaviors, and provide an integrational neural substrate for
the dynamic modulation of those behaviors by endocrine and sensory stimuli.
Although AVT/AVP behavioral functions and related anatomical features are
increasingly well-known for individual species, ubiquitous species-specificity
presents ever increasing challenges for identifying consistent
structure-function patterns that are broadly meaningful. Towards this end, we
provide a comprehensive review of the available literature on social behavior
functions of AVT/AVP and related anatomical characteristics, inclusive of
seasonal plasticity, sexual dimorphism, and steroid sensitivity. Based on this
foundation, we then advance three major questions which are fundamental to a
broad conceptualization of AVT/AVP social behavior functions: (1) Are there
sufficient data to suggest that certain peptide functions or anatomical
characteristics (neuron, fiber, and receptor distributions) are conserved across
the vertebrate classes? (2) Are independently-evolved but similar behavior
patterns (e.g. similar social structures) supported by convergent modifications
of neuropeptide mechanisms, and if so, what mechanisms? (3) How does AVT/AVP
influence behavior - by modulation of sensorimotor processes, motivational
processes, or both? Hypotheses based upon these questions, rather than those
based on individual organisms, should generate comparative data that will foster
cross-class comparisons which are at present underrepresented in the available
literature. Arginine vasotocin (AVT) and its mammalian homologoue arginine vasopressin (AVP)
influence male sexual and aggressive behaviors in many species. We tested the
effects of AVT and an AVP-V(1a) receptor antagonist on the display of
alternative male tactics in a tropical coral reef fish, the bluehead wrasse
Thalassoma bifasciatum. We gave AVT injections to territorial and nonterritorial
males of the large and colorful phenotype (terminal phase) and an AVP-V(1a)
receptor antagonist, Manning compound, to territorial males in the field. AVT
increased courtship independent of status, while its effects on territoriality
and aggression were dependent upon male status. In territorial males, AVT
increased courtship and tended to decrease the number of chases toward initial
phase individuals. In nonterritorial males, AVT increased courtship, chases
toward initial phase individuals, and territorial behavior while decreasing
feeding. These are all behaviors rarely seen in nonterritorial males, so AVT
made these males act like territorial TP males. The AVP-V(1a) receptor
antagonist had opposite effects. It decreased courtship and territorial defense,
making these males act more like nonterritorial males. Manipulations of the AVT
system shifted males within a single phenotype from the nonterritorial social
status to the territorial social status and vice versa. Since the entire suite
of behaviors related to territoriality was affected by AVT system manipulations,
our results suggest that the AVT system may play a key role in motivation of
behaviors related to mating. The avian homologs of arginine vasopressin (AVP) and oxytocin (OT) are arginine
vasotocin (AVT) and mesotocin (MT), respectively. In birds, AVT shares many of
the functions of AVP including regulation of fluid balance, blood pressure
regulation and the stress response. AVT also plays an oxytocin-like reproductive
role in birds by stimulating uterine (shell gland) contraction during
oviposition. The role of MT in avian reproduction is not clear. Here, we report
the cloning of a third neuropeptide receptor in the chicken (Gallus gallus).
Parsimony analysis reveals that the new receptor has highest homology to
mammalian OT receptors and the MT receptors of non-mammalian vertebrates.
Moreover, the receptor bears far less homology to the two avian VT receptors
that have been cloned. Reverse transcription-polymerase chain reaction and in in
situ hybridization analyses reveal the receptor is expressed in both the
endometrium and myometrium of the shell gland. The expression pattern and high
homology to OT receptors suggest that the receptor may stimulate myometrial
contraction and therefore play a critical role in oviposition. We report the discovery of conopressin-T, a novel bioactive peptide isolated
from Conus tulipa venom. Conopressin-T belongs to the vasopressin-like peptide
family and displays high sequence homology to the mammalian hormone oxytocin
(OT) and to vasotocin, the endogenous vasopressin analogue found in teleost
fish, the cone snail's prey. Conopressin-T was found to act as a selective
antagonist at the human V 1a receptor. All peptides in this family contain two
conserved amino acids within the exocyclic tripeptide (Pro7 and Gly9), which are
replaced with Leu7 and Val9 in conopressin-T. Whereas conopressin-T binds only
to OT and V 1a receptors, an L7P analogue had increased affinity for the V 1a
receptor and weak V2 receptor binding. Surprisingly, replacing Gly9 with Val9 in
OT and vasopressin revealed that this position can function as an
agonist/antagonist switch at the V 1a receptor. NMR structures of both
conopressin-T and L7P analogue revealed a marked difference in the orientation
of the exocyclic tripeptide that may serve as templates for the design of novel
ligands with enhanced affinity for the V 1a receptor. The neuropeptide arginine vasotocin (AVT) and its mammalian homologue arginine
vasopressin (AVP) are neuromodulators known to be steroid sensitive and
associated with social behaviors in a number of vertebrate taxa. However, the
role of AVT/P in the regulation of aggression remains unclear and contrasting
effects of this peptide on aggression are seen in differing species and
contexts. In this study, we used immunohistochemistry to examine the effects of
testosterone on the AVT system in male and female tree lizards, Urosaurus
ornatus, and to determine whether AVT is related to territorial aggression in
this species. Tree lizards are a free-living species that exhibit natural
hormonal fluctuations across breeding seasons. We detected a male-biased sexual
dimorphism in centrally projecting AVT fibers within the limbic system.
Furthermore, changes with season, reproductive state, and hormonal treatment
suggest that testosterone regulates AVT immunoreactivity in limbic brain
regions, especially in the bed nucleus of the stria terminalis. Testosterone
also affects AVT immunoreactivity in peripherally projecting cell clusters, as
well as the size of AVT cell bodies in the paraventricular nucleus. Although
higher testosterone levels alter AVT immunoreactivity, and are known to increase
the frequency and intensity of male-male aggression in this species, no
individual correlations between AVT immunoreactivity and aggression were
detected. Arginine vasotocin (VT), and its mammalian homologue arginine vasopressin (VP),
are neuropeptides involved in the regulation of social behaviors and stress
responsiveness. Previous research has demonstrated opposing effects of VT/VP on
aggression in different species. However, these divergent effects were obtained
in different social contexts, leading to the hypothesis that different
populations of VT/VP neurons regulate behaviors in a context-dependent manner.
We here use VP antagonists to block endogenous VT function in male zebra finches
(Taeniopygia guttata) within a semi-natural, mixed-sex colony setting. We
examine the role of VT in the regulation of aggression and courtship, and in
pair bond formation and maintece, over the course of three days. Although our
results confirm previous findings, in that antagonist treatment reduces
aggressive mate competition during an initial behavioral session during which
males encounter novel females, we find that the treatment effects are completely
reversed within hours of colony establishment, and the antagonist treatment
instead facilitates aggression in later sessions. This reversal occurs as
aggression shifts from mate competition to nest defense, but is not causally
associated with pairing status per se. Instead, we hypothesize that these
divergent effects reflect context-specific activation of hypothalamic and
amygdalar VT neurons that exert opposing influences on aggression. Across
contexts, effects were highly specific to aggression and the antagonist
treatment clearly failed to alter latency to pair bond formation, pair bond
stability, and courtship. However, VT may still potentially influence these
behaviors via promiscuous oxytocin-like receptors, which are widely distributed
in the zebra finch brain. The peptide hormone arginine vasotocin (AVT) and its mammalian homolog arginine
vasopressin modulate a variety of social behaviors in vertebrates. In anurans,
AVT influences the production of advertisement calls, the acoustic signals that
males use to attract females and repel rival males. In this study, we
investigate the effects of AVT on call characteristics in the túngara frog
(Physalaemus pustulosus). Túngara frogs produce a "whine" that is important for
species recognition; they may also produce a second, attractive call component,
the "chuck". We used a field playback experiment to determine changes in male
calling behavior following treatment with AVT. A previous study showed that AVT
alters call rate and the production of chucks; in the current analysis, we focus
on changes in the whine. Males produce shorter whines with higher initial
frequencies following treatment with AVT. Call changes do not vary with a social
stimulus. We also used female phonotaxis experiments to investigate the effects
of call changes on female mate choice. Females disfavor the calls produced by
males treated with exogenous AVT. We suggest that AVT influences motivation to
call and the motor control of call production, but that over-stimulation of the
vocal system limited the production of attractive calls in this experimental
context. The nonapeptide arginine vasotocin (AVT) and its mammalian homologue arginine
vasopressin play a key role in the regulation of social behaviour across
vertebrates. In teleost fishes, three AVT neuronal populations have been
described in the preoptic area (POA): the parvocellular (pPOA), the
magnocellular (mPOA) and the gigantocellular (gPOA). Neurons from each of these
areas project both to the pituitary and to other brain regions, where AVT is
supposed to regulate neural circuits underlying social behaviour. However, in
the fish species studied so far, there is considerable variation in which AVT
neuronal populations are involved in behavioural modulation and in the direction
of the effect. In this study, the association between AVT neuronal phenotypes
and social status was investigated in the Mozambique tilapia (Oreochromis
mossambicus). This species is an African female mouth-brooding cichlid fish in
which males form breeding aggregations in which domit males establish
territories and subordinate males to act as floaters. With respect to sex
differences in AVT neuronal phenotypes, females have a larger number of AVT
neurons in the pPOA and mPOA. Within males, AVT appeared associated with social
subordination, as indicated by the larger cell body areas of AVT neurons in mPOA
and gPOA nuclei of non-territorial males. There were also positive correlations
between submissive behaviour and the soma size of AVT cells in all three nuclei
and AVT cell number in the mPOA. In summary, the results provide evidence for an
involvement of AVT in the modulation of social behaviour in tilapia, but it was
not possible to identify specific roles for specific AVT neuronal populations.
The results presented here also contrast with those previously published for
another cichlid species with a similar mating system, which highlights the
species-specific nature of the pattern of association between AVT and social
behaviour even within the same taxonomic family. Arginine vasotocin (AVT) and the mammalian homologue, arginine vasopressin
(AVP), modulate vertebrate social behaviors, including vocalizations in male
anurans. To study the impact of AVT and social stimuli on calling in male
Xenopus tropicalis, we injected males with vehicle, 1 μg, or 10 μg AVT and
recorded vocalizations under four social contexts (no stimulus, with male call
playback, with a female, and with call playback and a female). More males called
when injected with 10 μg AVT. Furthermore, calling males called only when paired
with a female. We identified four call types: long fast trill; short fast trill;
slow trill; or click. Next, we injected males with vehicle, 10 μg, or 20 μg AVT
and recorded vocalizations with or without a female. AVT treatment did not
affect calling in this experiment, but we confirmed that more males, regardless
of AVT treatment, called when a female was present. Then we evaluated the effect
of human chorionic gonadotropin (hCG) on male sexual behavior. 20 IU hCG
elevated behavior compared to controls while the 10 IU hCG treatment group was
not different from either treatment. Last, we examined the effect of AVT on
hCG-induced reproductive behavior. Males were injected with 10 IU hCG or with 10
IU hCG and 20 μg AVT. Males receiving hCG and AVT clasped and called
significantly more than males receiving hCG only. Our results suggest that AVT
and a female stimulus induce vocalizations in a male pipid anuran, X.
tropicalis, and the interaction between gonadotropins and neurohormones
influences reproductive behaviors in this anuran amphibian. The neurohypophysial peptide arginine vasotocin (AVT) and its mammalian ortholog
arginine vasopressin function in a wide range of physiological and behavioral
events. Here, we generated a new line of transgenic medaka (Oryzias latipes),
which allowed us to monitor AVT neurons by enhanced green fluorescent protein
(EGFP) and demonstrate AVT neuronal development in the embryo and the projection
of AVT neurons in the adult brain of avt-egfp transgenic medaka. The onset of
AVT expression manifested at 2 days postfertilization (dpf) as a pair of signals
in the telencephalon of the brain. The telencephalic AVT neurons migrated and
converged on the preoptic area (POA) by 4dpf. At the same stage, another onset
of AVT expression manifested in the central optic tectum (OT), and they migrated
to the ventral part of the hypothalamus (VH) by 6dpf. In the adult brain, the
AVT somata with EGFP signals existed in the gigantocellular POA (gPOA),
magnocellular POA (mPOA), and parvocellular POA (pPOA) and in the VH. Whereas
the major projection of AVT fibers was found from the pPOA and VH to the
posterior pituitary, it was also found that AVT neurons in the three POAs send
their fibers into wide regions of the brain such as the telencephalon,
mesencephalon and diencephalon. This study suggests that the avt-egfp transgenic
medaka is a useful model to explore AVT neuronal development and function. Animals establish social hierarchies through agonistic behavior. The recognition
of the own and others social ranks is crucial for animals that live in groups to
avoid costly constant conflicts. Weakly electric fish are valuable model systems
for the study of agonistic behavior and its neuromodulation, given that they
display conspicuous electrocommunication signals that are generated by a very
well-known electromotor circuit. Brachyhypopomus gauderio is a gregarious
electric fish, presents a polygynous breeding system, morphological and
electrophysiological sexual dimorphism during the breeding season, and displays
a typical intrasexual reproduction-related aggression. Domits signal their
social status by increasing their electric organ discharge (EOD) rate after an
agonistic encounter (electric domice). Subordinates only occasionally produce
transient electric signals (chirps and offs). The hypothalamic neuropeptide
arginine-vasotocin (AVT) and its mammalian homologue, arginine- vasopressin
(AVP) are key modulators of social behavior across vertebrates. In this study,
we focus on the role of AVT on domice establishment in Brachyhypopomus
gauderio by analyzing the effects of pharmacological manipulations of the AVT
system in potential domits. AVT exerts a very specific direct effect
restricted only to EOD rate, and is responsible for the electric domice.
Unexpectedly, AVT did not affect the intensity of aggression in either
contender. Nor was the time structure affected by AVT administration. We also
present two interesting examples of the interplay between contenders by
evaluating how AVT modulations, even when directed to one individual, affect the
behavior of the dyad as a unit. First, we found that V1a AVT receptor antagonist
Manning Compound (MC) induces a reversion in the positive correlation between
domits' and subordinates' attack rates, observed in both control and AVT
treated dyads, suggesting that an endogenous AVT tone modulates aggressive
interactions. Second, we confirmed that AVT administered to domits induces an
increase in the submissive transient electric signals in subordinates. Nonapeptides play a fundamental role in the regulation of social behavior, among
numerous other functions. In particular, arginine vasopressin and its
non-mammalian homolog, arginine vasotocin (AVT), have been implicated in
regulating affiliative, reproductive, and aggressive behavior in many vertebrate
species. Where these nonapeptides are synthesized in the brain has been studied
extensively in most vertebrate lineages. While several hypothalamic and
forebrain populations of vasopressinergic neurons have been described in
amniotes, the consensus suggests that the expression of AVT in the brain of
teleost fish is limited to the hypothalamus, specifically the preoptic area
(POA) and the anterior tuberal nucleus (putative homolog of the mammalian
ventromedial hypothalamus). However, as most studies in teleosts have focused on
the POA, there may be an ascertainment bias. Here, we revisit the distribution
of AVT preprohormone mRNA across the dorsal and ventral telencephalon of a
highly social African cichlid fish. We first use in situ hybridization to map
the distribution of AVT preprohormone mRNA across the telencephalon. We then use
quantitative real-time polymerase chain reaction to assay AVT expression in the
dorsomedial telencephalon, the putative homolog of the mammalian basolateral
amygdala. We find evidence for AVT preprohormone mRNA in regions previously not
associated with the expression of this nonapeptide, including the putative
homologs of the mammalian extended amygdala, hippocampus, striatum, and septum.
In addition, AVT preprohormone mRNA expression within the basolateral amygdala
homolog differs across social contexts, suggesting a possible role in behavioral
regulation. We conclude that the surprising presence of AVT preprohormone mRNA
within dorsal and medial telencephalic regions warrants a closer examination of
possible AVT synthesis locations in teleost fish, and that these may be more
similar to what is observed in mammals and birds. |
Which kinase does PD98059 inhibit? | PD98059 is a specific, reversible MEK inhibitor. | PD98059 is a reversible MEK inhibitor that we are investigating as a potential
treatment for neurochemical changes in the brain that drive neurohumoral
excitation in heart failure. In a rat model that closely resembles human heart
failure, we found that central administration of PD98059 inhibits
phosphorylation of ERK1/2 in the paraventricular nucleus of the hypothalamus,
ultimately reducing sympathetic excitation which is a major contributor to
clinical deterioration. Studies revealed that the pharmacokinetics and
biodistribution of PD98059 match a two-compartment model, with drug found in
brain as well as other body tissues, but with a short elimination half-life in
plasma (approximately 73 min) that would severely limit its potential clinical
usefulness in heart failure. To increase its availability to tissues, we
prepared a sustained release PD98059-loaded PLGA microparticle formulation,
using an emulsion solvent evaporation technique. The average particle size,
yield percent, and encapsulation percent were found to be 16.73 μm, 76.6%, and
43%, respectively. In vitro drug release occurred over 4 weeks, with no
noticeable burst release. Following subcutaneous injection of the microparticles
in rats, steady plasma levels of PD98059 were detected by HPLC for up to
2 weeks. Furthermore, plasma and brain levels of PD98059 in rats with heart
failure were detectable by LC/MS, despite expected erratic absorption. These
findings suggest that PD98059-loaded microparticles hold promise as a novel
therapeutic intervention countering sympathetic excitation in heart failure, and
perhaps in other disease processes, including cancers, in which activated MAPK
signaling is a significant contributing factor. Graphical abstract. |
What is caused by loss-of-function variants in BCAS3? | Bi-allelic loss-of-function variants in BCAS3 cause a syndromic neurodevelopmental disorder. BCAS3 microtubule-associated cell migration factor (BCAS3) is a large, highly conserved cytoskeletal protein previously proposed to be critical in angiogenesis and implicated in human embryogenesis and tumorigenesis. | Author information:
(1)Department of Neurology and Hertie-Institute for Clinical Brain Research,
University of Tübingen, 72076 Tübingen, Germany; German Center of
Neurodegenerative Diseases, 72076 Tübingen, Germany.
(2)Division of Medical Genetics, Department of Pediatrics, Dalhousie University,
Halifax, NS B3K 6R8, Canada.
(3)Maritime Medical Genetics Service IWK Health Centre, Halifax, NS B3R 6R8
Canada.
(4)Institute of Human Genetics, Medical University of Innsbruck, Peter-Mayr.
Str. 1, 6020 Innsbruck, Austria; Institute of Human Genetics, Technical
University of Munich, Trogerstr. 32, 81675 Munich, Germany.
(5)Department of Pediatrics, Landeskrankenhaus Bregenz, Carl-Pedenz-Str. 2, 6900
Bregenz, Austria.
(6)Department of Pathology and Histology, Al-Quds University, Eastern Jerusalem
19356, Palestine.
(7)Palestine Medical Complex, Ramallah, Palestine.
(8)Department of Translational Genomics, Center for Genomic Medicine, King
Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia;
Department of Anatomy and Cell Biology, College of Medicine, Alfaisal
University, Riyadh 11533, Saudi Arabia.
(9)Department of Medical Genetics, King Faisal Specialist Hospital and Research
Center, Riyadh 11564, Saudi Arabia.
(10)Department of Translational Genomics, Center for Genomic Medicine, King
Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.
(11)Department of Molecular and Human Genetics, Baylor College of Medicine,
Houston, TX 77030, USA.
(12)Department of Medical Genetics, Cukurova University Faculty of Medicine,
01330 Adana, Turkey.
(13)Department of Molecular and Human Genetics, Baylor College of Medicine,
Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine,
Houston, TX 77030, USA.
(14)Department of Molecular and Human Genetics, Baylor College of Medicine,
Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine,
Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA.
(15)Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute,
Department of Neurosciences, University of California, San Diego, La Jolla, CA
92093, USA.
(16)Medical Genetics Research Center, Shahid Sadoughi University of Medical
Sciences, Yazd, Iran.
(17)Abortion Research Centre, Yazd Reproductive Sciences Institute, Shahid
Sadoughi University of Medical Sciences, Yazd, Iran.
(18)Department of Neurology and Institute of Human Genetics and Weill Institute
for Neurosciences, University of California, San Francisco, San Francisco, CA
94158, USA.
(19)GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877, USA.
(20)Department of Genetics, Faculty of Science, Shahid Chamran University of
Ahvaz, Ahvaz, Iran.
(21)Faculty of Medicine, Al-Quds University, Eastern Jerusalem 19356, Palestine.
(22)Department of Medical Genetics, Faculty of Medicine, Ahvaz Jundishapur
University of Medical Sciences, Ahvaz, Iran.
(23)Department of Paediatric Neurology, Golestan Medical, Educational, and
Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
(24)National Institute for Health Research Oxford Biomedical Research Centre,
Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.
(25)Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester
University NHS Foundation Trust, Health Innovation Manchester, Manchester M13
9WL, UK.
(26)Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester
University NHS Foundation Trust, Health Innovation Manchester, Manchester M13
9WL, UK; Division of Evolution and Genomic Sciences, School of Biological
Sciences, Faculty of Biology, Medicine, and Health, University of Manchester,
Manchester M13 9WL, UK.
(27)Division of Evolution and Genomic Sciences, School of Biological Sciences,
Faculty of Biology, Medicine, and Health, University of Manchester, Manchester
M13 9WL, UK.
(28)Children's Hospital of Eastern Ontario Research Institute, University of
Ottawa, Ottawa, ON K1H 8L1, Canada.
(29)Genomics England, London EC1M 6BQ, UK.
(30)Institute of Medical Genetics and Applied Genomics, University of Tübingen,
72076 Tübingen, Germany.
(31)Department of Neuroradiology, University Hospital of Tuebingen, 72076
Tübingen, Germany.
(32)Institute of Medical Genetics and Applied Genomics, University of Tübingen,
72076 Tübingen, Germany; NGS Competence Center Tübingen, University of Tübingen,
72076 Tübingen, Germany.
(33)Proteome Center Tübingen, University of Tübingen, 72076 Tübingen, Germany.
(34)Department of Neuromuscular Disorders, Queen Square Institute of Neurology,
University College London, London WC1N 3BG, UK.
(35)Department of Neuromuscular Disorders, Queen Square Institute of Neurology,
University College London, London WC1N 3BG, UK. Electronic address:
[email protected].
(36)Department of Neurology and Hertie-Institute for Clinical Brain Research,
University of Tübingen, 72076 Tübingen, Germany; German Center of
Neurodegenerative Diseases, 72076 Tübingen, Germany. Electronic address:
[email protected]. |
Which transporter is inhibited by Sotagliflozin? | Sotagliflozin, a dual inhibitor of sodium-glucose co-transporters 1 and 2. | The sodium-dependent glucose transporter 2 (SGLT2) inhibitors are an important
emerging class for the treatment of diabetes. Development of SGLT2 inhibitors
has been oriented around a desire for high selectivity for the SGLT2 protein
relative to the SGLT1 protein. More recently, genetic and pharmacology research
in mice has indicated that gastrointestinal SGLT1 inhibition may also be an
appropriate therapeutic target to treat diabetes. Combining SGLT1 and SGLT2
inhibition in a single molecule would provide complementary insulin-independent
mechanisms to treat diabetes. Therefore, sotagliflozin (LX4211) has been
developed as a dual inhibitor of SGLT1 and SGLT2. The differentiating clinical
features of dual inhibitor of SGLT1 and SGLT2 include a large postprandial
glucose reduction, elevation of glucagon-like peptide 1 and modest urinary
glucose excretion. These features may have clinical implications for the use of
sotagliflozin in the treatment of both type 1 and type 2 diabetes. INTRODUCTION: SGLT1 is the primary transporter responsible for the absorption of
glucose and galactose in the intestine, while SGLT2 and SGLT1 are both involved
in the renal reabsorption of glucose. SGLT2 inhibitors are a new class of oral
antidiabetic drugs, acting by increasing urinary glucose excretion (UGE). They
offer the advantages of a reduced risk of hypoglycaemia, a decrease in body
weight and blood pressure and an efficacy at all stages of type 2 diabetes
(T2DM).
AREAS COVERED: Herein, the authors focus specifically on sotagliflozin (LX4211),
the first-in-class dual SGLT1/SGLT2 inhibitor. Original publications in English
were selected as the basis of this review. Clinical trials were identified using
the Clinicaltrial.gov database.
EXPERT OPINION: By a potential additional mechanism of action on intestinal
glucose absorption linked to SGLT1 inhibition, sotagliflozin differentiates from
SGLT2 inhibitors by reducing postprandial glucose excursion and insulin
secretion, as well as by increasing GLP-1 secretion. Despite a weaker effect on
UGE than selective SGLT2 inhibitors, sotagliflozin is as effective as SGLT2
inhibitors on HbA1C reduction, with a similar safety profile in short-term
studies. While sotagliflozin was first assessed in T2DM, it is now in phase 3
development as an adjuvant treatment in patients with T1DM after positive
results from a pilot study. Type 2 Diabetes Mellitus (T2DM) and Alzheimer's disease (AD) are the two
disorders which are known to share pertinent pathological and therapeutic links.
Sodium glucose co-transporter-2 (SGLT2) and Acetylcholinesterase (AChE) are
established inhibition targets for T2DM and AD treatments, respectively. Reports
suggest that anti-diabetic drugs could be used for AD treatment also. The
present study used molecular docking by Autodock4.2 using our
"Click-By-Click"-protocol, Ligplot1.4.3 and "change in accessible surface area
(ΔASA)-calculations" to investigate the binding of two investigational
anti-diabetic drugs, Ertugliflozin and Sotagliflozin to an established target
(SGLT2) and a research target (human brain AChE). Sotagliflozin appeared more
promising for SGLT2 as well as AChE-inhibition with reference to ΔG and Ki
values in comparison to Ertugliflozin. The ΔG and Ki values for
"Sotagliflozin:AChE-binding" were -7.16 kcal/mol and 5.6 μM, respectively while
the same were found to be -8.47 kcal/mol and 0.62 μM, respectively for its
interaction with SGLT2. Furthermore, "Sotagliflozin:SGLT2-interaction" was
subjected to (un)binding simulation analyses by "Molecular-Motion-Algorithms."
This information is significant as the exact binding mode, interacting amino
acid residues and simulation results for the said interaction have not been
described yet. Also no X-ray crystal is available for the same. Finally, the
results described herein indicate that Sotagliflozin could have an edge over
Ertugliflozin for treatment of Type 2 diabetes. Future design of drugs based on
Sotagliflozin scaffolds for treatment of Type 2 and/or Type 3 diabetes are
highly recommended. As these drugs are still in late phases of clinical trials,
the results described herein appear timely. J. Cell. Biochem. 118: 3855-3865,
2017. © 2017 Wiley Periodicals, Inc. BACKGROUND: In most patients with type 1 diabetes, adequate glycemic control is
not achieved with insulin therapy alone. We evaluated the safety and efficacy of
sotagliflozin, an oral inhibitor of sodium-glucose cotransporters 1 and 2, in
combination with insulin treatment in patients with type 1 diabetes.
METHODS: In this phase 3, double-blind trial, which was conducted at 133 centers
worldwide, we randomly assigned 1402 patients with type 1 diabetes who were
receiving treatment with any insulin therapy (pump or injections) to receive
sotagliflozin (400 mg per day) or placebo for 24 weeks. The primary end point
was a glycated hemoglobin level lower than 7.0% at week 24, with no episodes of
severe hypoglycemia or diabetic ketoacidosis after randomization. Secondary end
points included the change from baseline in glycated hemoglobin level, weight,
systolic blood pressure, and mean daily bolus dose of insulin.
RESULTS: A significantly larger proportion of patients in the sotagliflozin
group than in the placebo group achieved the primary end point (200 of 699
patients [28.6%] vs. 107 of 703 [15.2%], P<0.001). The least-squares mean change
from baseline was significantly greater in the sotagliflozin group than in the
placebo group for glycated hemoglobin (difference, -0.46 percentage points),
weight (-2.98 kg), systolic blood pressure (-3.5 mm Hg), and mean daily bolus
dose of insulin (-2.8 units per day) (P≤0.002 for all comparisons). The rate of
severe hypoglycemia was similar in the sotagliflozin group and the placebo group
(3.0% [21 patients] and 2.4% [17], respectively). The rate of documented
hypoglycemia with a blood glucose level of 55 mg per deciliter (3.1 mmol per
liter) or below was significantly lower in the sotagliflozin group than in the
placebo group. The rate of diabetic ketoacidosis was higher in the sotagliflozin
group than in the placebo group (3.0% [21 patients] and 0.6% [4], respectively).
CONCLUSIONS: Among patients with type 1 diabetes who were receiving insulin, the
proportion of patients who achieved a glycated hemoglobin level lower than 7.0%
with no severe hypoglycemia or diabetic ketoacidosis was larger in the group
that received sotagliflozin than in the placebo group. However, the rate of
diabetic ketoacidosis was higher in the sotagliflozin group. (Funded by Lexicon
Pharmaceuticals; inTandem3 ClinicalTrials.gov number, NCT02531035 .). AIMS: To evaluate the evidence for the novel dual sodium-glucose
co-transporter-1 (SGLT1) and -2 (SGLT2) inhibitor, sotagliflozin, which may
enhance the efficacy of SGLT2 inhibitors by additionally reducing intestinal
glucose absorption.
METHODS: The search terms 'sotagliflozin', 'LX4211', 'SGLT' and 'diabetes' were
entered into PubMed. Evidence for the pharmacokinetics, pharmacodynamics, safety
and efficacy of sotagliflozin in Type 1 and 2 diabetes was extracted from the
retrieved literature, critically evaluated, and contextualized in relation to
data on existing SGLT2 inhibitors.
RESULTS: There is convincing evidence from a range of phase II and III clinical
trials that sotagliflozin significantly improves glycaemic control in both Type
1 and Type 2 diabetes. Additional benefits, such as smaller postprandial plasma
glucose excursions, lower insulin requirements, appetite suppression and weight
loss have been documented. While this is encouraging, several safety concerns
remain; a dose-dependent increase in the rate of diabetic ketoacidosis,
diarrhoea and genital mycotic infection is apparent, although statistical
exploration of the data regarding such events is currently lacking.
Speculatively, use of a 200-mg rather than a 400-mg dose may help to limit
unwanted effects.
CONCLUSIONS: The current evidence for sotagliflozin in diabetes appears
promising. Further studies sufficiently powered to assess present and emerging
safety concerns, as well as to identify individuals for whom sotagliflozin may
be of particular benefit/harm would now be informative for regulatory
decision-making. Direct comparisons with existing SGLT2 inhibitors are also
needed to determine relative safety/efficacy profiles for the different
indications. The sodium-glucose cotransporter type 1 (SGLT1) is the primary transporter for
absorption of glucose and galactose in the gastrointestinal tract. Inhibition
blunts and delays postprandial glucose (PPG) excursion. Sodium-glucose
cotransporter type 2 (SGLT2) is expressed in the kidney, where it reabsorbs 90%
of filtered glucose. Thus, a dual SGLT1 and SGLT2 inhibition (compared with
selective SGLT2 inhibition) could result in lower PPG and robust A1c reduction
even in patients with reduced kidney function. Sotagliflozin is an oral potent
dual inhibitor of the insulin-independent SGLT1 and SGLT2. Preliminary data
released from phase 2 and 3 clinical studies in adults with type 1 diabetes
mellitus (T1DM) and type 2 diabetes mellitus (T2DM) showed improved glycemic
control, and met efficacy endpoints beyond A1c with a safety profile consistent
with the SGLT class: significant reduction in body weight, systolic blood
pressure, and efficacy maintained in lower estimated glomerular filtration rate
levels with no increased hypoglycemia. Increased risk of diabetic ketoacidosis
(DKA) with uncharacteristically mild-to-moderate glucose elevations (euglycemic
DKA) is associated with the use of all the approved SGLT2 inhibitors. Factors
that trigger DKA include insulin reductions, low caloric and fluid intake,
intercurrent illness, and alcohol use. However, DKA is detectable and manageable
with proper patient education. With sotagliflozin, DKA rates were not higher
than the expected background rate in T1DM, but numerically higher than placebo.
Sotagliflozin is the first oral SGLT1 and SGLT2 inhibitor developed for the
treatment of adult patients with T1DM, in adjunct with insulin, and has the
potential to address unmet needs for patients with T1DM and possibly T2DM, with
a favorable benefit/risk profile. OBJECTIVE: Evaluate the efficacy and safety of the dual sodium-glucose
cotransporter 1 (SGLT1) and SGLT2 inhibitor sotagliflozin in combination with
optimized insulin in type 1 diabetes (T1D).
RESEARCH DESIGN AND METHODS: The inTandem1 trial, a double-blind, 52-week phase
3 trial, randomized North American adults with T1D to placebo (n = 268),
sotagliflozin 200 mg (n = 263), or sotagliflozin 400 mg (n = 262) after 6 weeks
of insulin optimization. The primary end point was HbA1c change from baseline at
24 weeks. HbA1c, weight, and safety were also assessed through 52 weeks.
RESULTS: From a mean baseline of 7.57%, placebo-adjusted HbA1c reductions were
0.36% and 0.41% with sotagliflozin 200 and 400 mg, respectively, at 24 weeks and
0.25% and 0.31% at 52 weeks (all P < 0.001). Among patients with a baseline
HbA1c ≥7.0%, an HbA1c <7% was achieved by 15.7%, 27.2%, and 40.3% of patients
receiving placebo, sotagliflozin 200 mg, and sotagliflozin 400 mg, respectively
(P ≤ 0.003 vs. placebo) at 24 weeks. At 52 weeks, mean treatment differences
between sotagliflozin 400 mg and placebo were -1.08 mmol/L for fasting plasma
glucose, -4.32 kg for weight, and -15.63% for bolus insulin dose and -11.87% for
basal insulin dose (all P < 0.001). Diabetes Treatment Satisfaction
Questionnaire scores increased significantly by 2.5 points with sotagliflozin
versus placebo (P < 0.001) at 24 weeks. Genital mycotic infections and diarrhea
occurred more frequently with sotagliflozin. Adjudicated diabetic ketoacidosis
(DKA) occurred in 9 (3.4%) and 11 (4.2%) patients receiving sotagliflozin 200
and 400 mg, respectively, and in 1 (0.4%) receiving placebo. Severe hypoglycemia
occurred in 17 (6.5%) patients from each sotagliflozin group and 26 (9.7%)
patients receiving placebo.
CONCLUSIONS: In a 1-year T1D study, sotagliflozin combined with optimized
insulin therapy was associated with sustained HbA1c reduction, weight loss,
lower insulin dose, fewer episodes of severe hypoglycemia, improved
patient-reported outcomes, and more DKA relative to placebo (ClinicalTrials.gov,
NCT02384941). Sotagliflozin is a dual sodium-glucose co-transporter-2 and 1 (SGLT2/1)
inhibitor for the treatment of both type 1 (T1D) and type 2 diabetes (T2D).
Sotagliflozin inhibits renal sodium-glucose co-transporter 2 (determining
significant excretion of glucose in the urine, in the same way as other, already
available SGLT-2 selective inhibitors) and intestinal SGLT-1, delaying glucose
absorption and therefore reducing post prandial glucose. Well-designed clinical
trials, have shown that sotagliflozin (as monotherapy or add-on therapy to other
anti-hyperglycemic agents) improves glycated hemoglobin in adults with T2D, with
beneficial effects on bodyweight and blood pressure. Similar results have been
obtained in adults with T1D treated with either continuous subcutaneous insulin
infusion or multiple daily insulin injections, even after insulin optimization.
A still ongoing phase 3 study is currently evaluating the effect of
sotagliflozin on cardiovascular outcomes (ClinicalTrials.gov NCT03315143). In
this review we illustrate the advantages and disadvantages of dual SGLT 2/1
inhibition, in order to better characterize and investigate its mechanisms of
action and potentialities. Two large-scale mouse gene knockout phenotyping campaigns have provided
extensive data on the functions of thousands of mammalian genes. The ongoing
International Mouse Phenotyping Consortium (IMPC), with the goal of examining
all ∼20,000 mouse genes, has examined 5115 genes since 2011, and phenotypic data
from several analyses are available on the IMPC website
(www.mousephenotype.org). Mutant mice having at least one human genetic
disease-associated phenotype are available for 185 IMPC genes. Lexicon
Pharmaceuticals' Genome5000™ campaign performed similar analyses between 2000
and the end of 2008 focusing on the druggable genome, including enzymes,
receptors, transporters, channels and secreted proteins. Mutants (4654 genes,
with 3762 viable adult homozygous lines) with therapeutically interesting
phenotypes were studied extensively. Importantly, phenotypes for 29 Lexicon
mouse gene knockouts were published prior to observations of similar phenotypes
resulting from homologous mutations in human genetic disorders. Knockout mouse
phenotypes for an additional 30 genes mimicked previously published human
genetic disorders. Several of these models have helped develop effective
treatments for human diseases. For example, studying Tph1 knockout mice (lacking
peripheral serotonin) aided the development of telotristat ethyl, an approved
treatment for carcinoid syndrome. Sglt1 (also known as Slc5a1) and Sglt2 (also
known as Slc5a2) knockout mice were employed to develop sotagliflozin, a dual
SGLT1/SGLT2 inhibitor having success in clinical trials for diabetes. Clinical
trials evaluating inhibitors of AAK1 (neuropathic pain) and SGLT1 (diabetes) are
underway. The research community can take advantage of these unbiased analyses
of gene function in mice, including the minimally studied 'ignorome' genes. AIMS: To identify and synthesize phase 3 and phase 4 randomized controlled
trials (RCTs) of sodium-glucose co-transporter (SGLT) inhibitors and metformin
as adjuncts to insulin in type 1 diabetes (T1DM) using network meta-analysis
(NMA).
MATERIALS AND METHODS: A systematic literature review (SLR) identified relevant
RCTs of ≥12 Weeks duration. MEDLINE, Embase, the Cochrane Library and grey
literature were searched through October 2018. NMAs indirectly compared SGLT
inhibitors and metformin for change from baseline in HbA1c, weight, total daily
insulin dose and systolic blood pressure at Week 24 to 26 and Week 52. Safety
outcomes were also explored.
RESULTS: Nine trials (N = 6780) were included in the SLR. NMAs indicated that
all therapies performed better than placebo for the efficacy outcomes at both
time points. Compared with metformin at Week 24 to 26, the SGLT inhibitors
dapagliflozin (5 mg), sotagliflozin (200 mg) and empagliflozin (10 mg) had
larger reductions in HbA1c (mean difference [MD] = -0.24, 95% credible interval
[CrI], -0.41 to -0.07, MD = -0.23, 95% CrI, -0.39 to -0.08 and MD = -0.35, 95%
CrI, -0.51 to -0.19, respectively) and in weight, which were sustained in
sensitivity analyses. There were few differences observed in the results of
safety outcomes, such as risk of diabetic ketoacidosis (DKA), which should be
interpreted cautiously because of wide CrIs.
CONCLUSIONS: Adjunctive use of SGLT inhibitors in T1DM can improve glycaemic
control compared with metformin while enabling weight loss, with consistent
efficacy across the class. However, these results are based on indirect evidence
so confirmation in a head-to-head study would be valuable. Sotagliflozin (Zynquista™) is the first dual inhibitor of sodium-glucose
co-transporter-1 and -2 (SGLT1 and 2). In the phase 3, inTANDEM 1-3 trials,
adjunctive use of oral sotagliflozin (200 mg or 400 mg once daily) improved
glycaemic control and reduced bodyweight and insulin requirements relative to
placebo over 24 weeks of treatment in adults whose type 1 diabetes (T1D) was
inadequately controlled by insulin therapy. Similar benefits were seen with the
drug in patients who were overweight/obese [i.e. body mass index (BMI)
≥ 27 kg/m2] in inTANDEM 1 and 2 (pooled). The benefits of sotagliflozin were
largely maintained over 52 weeks of treatment. Overall, use of sotagliflozin in
this setting is generally well tolerated and reduces, or at least does not
increase, the likelihood of hypoglycaemia; however, as with other SGLT
inhibitors, sotagliflozin carries a risk of diabetic ketoacidosis (DKA). On the
basis of its risk/benefit profile, sotagliflozin is indicated in the EU as an
adjunct to insulin in adults with T1D with a BMI ≥ 27 kg/m2 who have failed to
achieve adequate glycaemic control despite optimal insulin therapy, thus
expanding the currently limited adjunctive oral treatment options available for
use in this population. A mild and convenient method for the synthesis of reverse glycosyl fluorides
(RGFs) has been developed that is based on the silver-promoted radical
dehydroxymethylative fluorination of carbohydrates. A salient feature of the
reaction is that furanoid and pyranoid carbohydrates furnish structurally
diverse RGFs bearing a wide variety of functional groups in good to excellent
yields. Intramolecular hydrogen atom transfer experiments revealed that the
reaction involves an underexploited radical fluorination that proceeds via
β-fragmentation of sugar-derived primary alkoxyl radicals. Structurally
divergent RGFs were obtained by catalytic C-F bond activation, and our method
thus offers a concise and efficient strategy for the synthesis of reverse
glycosides by late-stage diversification of RGFs. The potential of this method
is showcased by the preparation and diversification of sotagliflozin, leading to
the discovery of a promising SGLT2 inhibitor candidate. In spite of developments with novel insulin preparations, novel modes of insulin
delivery with insulin infusion pumps, and the facility of continuous glucose
monitoring, only 20% of patients with type 1 diabetes are under adequate
control. The need for innovation is clear, and, therefore, the use of adjunct
therapies with other pharmacological agents currently in use for type 2
diabetes, has been tried. Currently, pramlintide is the only agent licensed for
use in this condition in addition to insulin. Global trials have been conducted
with liraglutide, a glucagon-like peptide 1 receptor agonist (GLP-1RA),
dapagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, and
sotagliflozin, an inhibitor of both SGLT1 and SGLT2 transporters. While
dapagliflozin and sotagliflozin have now been licensed for clinical use in this
condition in Europe and Japan, they have hitherto not been licensed in the
United States due to a small increase in the risk of diabetic ketoacidosis.
However, these agents reduce glycosylated hemoglobin (HbA1c) by 0.4%, reduce
glycemic oscillations, and do not increase the risk of hypoglycemia.
Liraglutide, on the other hand, induced a smaller reduction in HbA1c and thus
was not considered for a license. However, further trials are currently being
conducted with a combination of semaglutide, the most potent GLP-1RA, and
dapagliflozin to determine whether this approach would yield better outcomes. Diabetes mellitus is the global health issue and become an alarming threat in
the modern era where human lifestyle gets compromised with modernization.
According to the latest statistical report 2020, USA has 9.47% (31 million among
32.72 cr), China has 8.3% (116.4 million among 139.27 cr) and India has 5.6% (77
million among 135.26 cr) of the diabetic people, indicating that diabetes is
more prevailing in developed countries as compared to the developing countries.
The number of diabetic patients is rising day by day at a tremendous rate and
soon it may affect each and every person in a family. So, there is an urgent
need to develop novel entities that can meet the scarcity of present
antidiabetic agents. In the last few decades, the sodium-glucose co-transporter
2 (SGLT2) has emerged as a prominent target for the treatment of Type 2 diabetes
mellitus due to its novel mechanism of action & no involvement in insulin
signaling pathway. Most of the inhibitors that target SGLT2 contain three basic
moieties: glucose, two benzene rings (one is connected with glucose and the
other with methylene), and the methylene bridge which are similar to
dapagliflozin. Several SGLT2 inhibitors and their derivatives such as
remogliflozin etabonate (phase-II), sotagliflozin (phase-III) and bexagliflozin
(phase-III) are under different phases of clinical trial studies and some have
been patented. The present review is focused on SGLT2 inhibitors, structure
activity relationships (SARs) of dapagliflozin and its several analogues for
their binding affinity with SGLT2. We have also presented and summarized the
efforts made by various researchers in terms of the synthesis of various
dapagliflozin derivatives till date. INTRODUCTION: The majority of patients with type 1 diabetes mellitus (T1DM) do
not achieve glycemic targets. In addition, treatment with insulin is associated
with increased risk for hypoglycemia and weight gain. Accordingly, there is an
unmet need for new safe and effective glucose-lowering agents in this
population. Sotagliflozin, a dual inhibitor of sodium-glucose co-transporters 1
and 2, has been recently approved for use in patients with T1DM.
AREAS COVERED: The authors review the major trials that have evaluated the
safety and efficacy of sotagliflozin and provide their expert opinion.
EXPERT OPINION: Even though sotagliflozin reduces HbA1 c levels and does not
appear to increase the risk for hypoglycemia in most patients, the substantially
increased risk for diabetic ketoacidosis limits the use of this agent to a
carefully selected subgroup of patients with T1DM. Based on the existing
evidence, sotagliflozin should be considered only in patients who have failed to
achieve adequate glycemic control despite optimal insulin therapy, are at low
risk for diabetic ketoacidosis, have been adequately trained to recognize this
complication and are able to be in close contact with their physician. Dapagliflozin (SGLT-2 inhibitor) and sotagliflozin (SGLT1/2 inhibitor) are two
of the drugs of SGLT inhibitor class which have been recommended by the National
Institute for Health and Care Excellence (NICE) in people with type 1 diabetes
with BMI ≥27 kg/m2 . Dapagliflozin is licensed in the UK for use in the NHS
while sotagliflozin may be available in future. These and possibly other SGLT
inhibitors may be increasingly used in people with type 1 diabetes as new
licences are obtained. These drugs have the potential to improve glycaemic
control in people with type 1 diabetes with the added benefit of weight loss,
better control of blood pressure and more time in optimal glucose range.
However, SGLT inhibitors are associated with a higher incidence of diabetic
ketoacidosis without significant hyperglycaemia. The present ABCD/Diabetes UK
joint updated position statement is to guide people with type 1 diabetes and
clinicians using these drugs help mitigate this risk and other potential
complications. Particularly, caution needs to be exercised in people who are at
risk of diabetic ketoacidosis due to low calorie diets, illnesses, injuries,
starvation, excessive exercise, excessive alcohol consumption and reduced
insulin administration among other precipitating factors for diabetic
ketoacidosis. Publisher: Chronisch nierenkranke Patienten weisen eine erhöhte kardiovaskuläre
Morbidität und Sterblichkeit auf. Im letzten Jahr sind einige wichtige Studien
zur Herz-Nieren-Interaktion veröffentlicht worden, die im Folgenden
zusammengefasst und diskutiert werden. In der DAPA-CKD-Studie sowie in der
SCORED-Studie konnten 2 unterschiedliche SGLT2(„sodium-glucose linked
transporter 2“)-Inhibitoren (Dapagliflozin und Sotagliflozin) die Prognose von
chronisch nierenkranken Patienten mit und ohne Diabetes nachweislich verbessern.
Auch die Ergebnisse der randomisierten Studie zum neuen
Mineralokortikoidrezeptorantagonisten Finerenon – FIDELIO-DKD – liefern einen
vielversprechenden neuen Therapieansatz für Patienten mit diabetischer
Nephropathie. Die veröffentlichten Daten der ISCHEMIA-CKD-Studie bei Patienten
mit koronarer Herzkrankheit und Untersuchungen zum Einfluss einer TAVI
(„transcatheter aortic valve implantation“) auf die Nierenfunktion sowie eine
weitere Studie zum akuten Nierenversagen nach MitraClip®-Implantation (Abbott,
Chicago, IL, USA) geben wichtige Hinweise zu zukünftigen Handlungsempfehlungen.
Der optimale Zeitpunkt der Einleitung einer Nierenersatztherapie bei Patienten
mit akuter Nierenschädigung in der Intensivmedizin wurde in 2 randomisierten
Studien untersucht, die entsprechend diskutiert werden. Sotagliflozin is a dual sodium-glucose co-transporter (SGLT) 2 inhibitor,
manifesting a 20-fold higher inhibitory activity for SGLT2 than for SGLT1.
Differences in SGLT2 over SGLT1 selectivity of the available agents have been
proposed to relate to variability in efficacy and safety characteristics. In
contrast to other SGLT2 inhibitors, the cardiorenal effects of sotagliflozin in
type 2 diabetes had not been explored until recently, when the results of
SOLOIST-WHF (focusing on heart failure [HF] outcomes) and SCORED (focusing on
renal outcomes) were published. In SOLOIST-WHF, sotagliflozin reduced the risk
of the primary composite outcome of cardiovascular (CV) death and
hospitalizations and urgent visits for HF. The findings showed that the risk
reduction was consistent in people with reduced but also in those with preserved
ejection fraction (EF). In SCORED, sotagliflozin significantly reduced the
primary end point of CV deaths, hospitalizations for HF, and urgent visits for
HF. A reduction in glycated hemoglobin was evident even in participants with
estimated glomerular filtration rate values below 30 mL/min/1.73 m2. SCORED is
also the first trial to illustrate the benefits of the class across the full
range of albuminuria. Moreover, the endpoint of stroke was significantly reduced
by 34% in the sotagliflozin compared with the placebo group. The findings of the
two studies provide novel insights into the clinical utility of SGLT2
inhibitors, particularly with respect to the early initiation in stable HF, the
benefits in HF with preserved EF, the glucose-lowering efficacy in people with
severe renal impairment and their potential to improve atherosclerotic vascular
disease, including stroke, outcomes. |
What is the main use of ETD fragmentation? | Electron-based fragmentation methods have revolutionized biomolecular mass spectrometry, in particular native and top-down protein analysis. | Electron-based fragmentation methods have revolutionized biomolecular mass
spectrometry, in particular native and top-down protein analysis. Here, we
report the use of a new electromagnetostatic cell to perform electron capture
dissociation (ECD) within a quadrupole/ion mobility/time-of-flight mass
spectrometer. This cell was installed between the ion mobility and
time-of-flight regions of the instrument, and fragmentation was fast enough to
be compatible with mobility separation. The instrument was already fitted with
electron transfer dissociation (ETD) between the quadrupole and mobility regions
prior to modification. We show excellent fragmentation efficiency for denatured
peptides and proteins without the need to trap ions in the gas phase.
Additionally, we demonstrate native top-down backbone fragmentation of
noncovalent protein complexes, leading to comparable sequence coverage to what
was achieved using the instrument's existing ETD capabilities. Limited
collisional ion activation of the hemoglobin tetramer before ECD was reflected
in the observed fragmentation pattern, and complementary ion mobility
measurements prior to ECD provided orthogonal evidence of monomer unfolding
within this complex. The approach demonstrated here provides a powerful platform
for both top-down proteomics and mass spectrometry-based structural biology
studies. Middle-down proteomics has emerged as the method of choice to study
combinatorial histone post translational modifications (PTMs). In the common
bottom-up workflow, histones are digested into relatively short peptides (4-20
aa), separated using reversed-phase chromatography and analyzed using typical
proteomics methods in mass spectrometry. In middle-down, histones are cleaved
into longer polypeptides (50-60 aa) mostly corresponding to their N-terminal
tails, resolved using weak cation exchange-hydrophilic interaction liquid
chromatography (WCX-HILIC) and analyzed with less conventional mass
spectrometry, i.e. using Electron Transfer Dissociation (ETD) for analyte
fragmentation. Middle-down is not nearly as utilized as bottom-up for PTM
analysis, partially due to its limited reproducibility and robustness. This has
also limited the establishment of rigorous benchmarks to discriminate good vs
poor quality experiments. Here, we describe critical aspects of the middle-down
workflow to assist the user in evaluating the presence of biased and misleading
results. Specifically, we tested the use of porous graphitic carbon (PGC) during
the desalting step, demonstrating that desalting using only C18 material leads
to sample loss. We also tested different salts in the WCX-HILIC buffers for
their effect on retention, selectivity, and reproducibility of analysis of
variants of histone tail fragments, in particular replacing ammonium ion with
ethylenediammonium ion in buffer A. These substitutions had marked effects on
selectivity and retention. Our results provide a streamlined way to evaluate
middle-down performance to identify and quantify combinatorial histone PTMs. O-glycosylation is a highly diverse and complex form of protein
post-translational modification. Mucin-type O-glycosylation is initiated by the
transfer of N-acetyl-galactosamine (GalNAc) to the hydroxyl group of serine,
threonine and tyrosine residues through catalysis by a family of
glycosyltransferases, the UDP-GalNAc:polypeptide
N-acetylgalactosaminyltransferases (E.C. 2.4.1.41) that are conserved across
metazoans. In the last decade, structural characterization of glycosylation has
substantially advanced due to the development of analytical methods and advances
in mass spectrometry. However, O-glycosite mapping remains challenging since
mucin-type O-glycans are densely packed, often protecting proteins from cleavage
by proteases. Adding to the complexity is the fact that a given glycosite can be
modified by different glycans, resulting in an array of glycoforms rising from
one glycosite. In this study, we investigated conditions of solid phase
extraction (SPE) enrichment, protease digestion, and Electron-transfer/Higher
Energy Collision Dissociation (EThcD) fragmentation to optimize identification
of O-glycosites in densely glycosylated proteins. Our results revealed that
anion-exchange stationary phase is sufficient for glycopeptide enrichment;
however, the use of a hydrophobic-containing sorbent was detrimental to the
binding of polar-hydrophilic glycopeptides. Different proteases can be employed
for enhancing coverage of O-glycosites, while derivatization of negatively
charged amino acids or sialic acids would enhance the identification of a short
O-glycopeptides. Using a longer than normal electron transfer dissociation (ETD)
reaction time, we obtained enhanced coverage of peptide bonds that facilitated
the localization of O-glycosites. O-glycosite mapping strategy via proteases,
cut-off filtration and solid-phase chemoenzymatic processing. Glycopeptides are
enriched by SPE column, followed by release of N-glycans, collection of higher
MW O-glycopeptides via MW cut-off filter, O-glycopeptide release via O-protease,
and finally detected by LC-MS/MS using EThcD. Electron transfer dissociation (ETD) is an analytically useful tool for primary
structure interrogation of intact proteins, but its utility is limited by
higher-order reactions with the products. To inhibit these higher-order
reactions, first-generation fragment ions are kinetically excited by applying an
experimentally tailored parallel ion parking waveform during ETD (ETD-PIP). In
combination with subsequent ion/ion proton transfer reactions,
precursor-to-product conversion was maximized as evidenced by the consumption of
more than 90% of the 21 kDa Protein G precursor to form ETD product ions. The
employment of ETD-PIP increased sequence coverage to 90% from 80% with standard
ETD. Additionally, the inhibition of sequential electron transfers was reflected
in the high number of complementary ion pairs from ETD-PIP (90%) compared to
standard ETD (39%). |
What is the Bartter syndrome? | Bartter syndrome is a rare disorder characterized by reduced sodium chloride transport in the distal nephrons of the kidney. Its clinical features are renal salt wasting, hypokalemic metabolic alkalosis, elevated renin and aldosterone levels with normal or low blood pressure, polyuria, hypercalciuria and malnutrition. | Bartter's syndrome is a congenital abnormality characterized by metabolic
alkalosis [corrected], hyperreninemic hyperaldosteronism, and hypokalemia. Most
patients present early in life with symptoms such as muscle weakness and
polyuria, which may be attributed to potassium depletion. Despite the
hyperaldosteronism, the patients tend to be normotensive, which is at least
partially explained by vascular hyporesponsiveness to pressor hormones. Numerous
studies have documented increased renal excretion of prostaglandins. Several
different patterns of aberrant renal ion transport have been observed in
patients with the syndrome, suggesting that it actually may represent a family
of related but distinct tubular disorders. Therapeutic approaches to Bartter's
syndrome include potassium supplementation, prostaglandin synthesis inhibitors
(nonsteroidal anti-inflammatory agents), aldosterone antagonists, and converting
enzyme inhibitors. During the first two decades following its initial
description, Bartter's syndrome was the focus of widespread interest, based on
the likelihood that its investigation might provide insight into the normal
functioning of the renin-angiotensin-aldosterone and prostanoid hormone systems.
During the past decade, however, little additional progress has been made in
Bartter's syndrome, and its patho-physiology remains poorly understood. Bartter's syndrome (BS) is a disease with severe hypokalaemia due to renal
potassium wasting. The potassium loss is due to lesions at different sites
within the renale tubule. Additional features include metabolic alkalosis,
excess renal production of prostaglandins, hyperreninaemia, hyperaldosteronism
and impaired pressor responses to exogenous angiotensin II. These secondary
features are the result of renal potassium wasting. Symptoms are due to
potassium deficiency, but many adult patients feel well despite marked
hypokalaemia. The hypocalciuric variant of BS is called Gitelman's syndrome.
These patients have a more benign course. The diagnosis of BS is one of
exclusion, mainly of surreptitious vomiting, diuretic or laxative abuse. The
primary treatment is potassium supplementation often in combination with
potassium-sparing diuretics, prostaglandin inhibitors or ACE-inhibitors. With
coexisting magnesium deficiency, magnesium supplementation might be effective. Bartter syndrome involves an overlapping set of closely related renal tubular
disorders which can be subdivided into at least three clinical phenotypes: (1)
classic Bartter syndrome (2) Gitelman syndrome, and (3) a neonatal variant of
Bartter syndrome. In contrast to classic Bartter syndrome and Gitelman syndrome,
the neonatal variant of Bartter syndrome has both the features of renal tubular
hypokalemic alkalosis as well as profound systemic manifestations. Specifically,
neonatal Bartter syndrome is characterized by intrauterine polyhydramnios,
premature delivery, and life-threatening episodes of fever and dehydration. Most
of these infants also have severe hypercalciuria with associated
nephrocalcinosis and osteopenia. Over a 22-year period, 20 Costa Rican patients
with a congenital syndrome that resembles neonatal Bartter syndrome have been
identified and characterized. While these patients exhibit some of the clinical
characteristics previously described for neonatal Bartter syndrome, this cohort
also has a set of distinct features. They are predomitly female, have a later
age of diagnosis, manifest a relatively unique set of physical traits, and
appear to have milder clinical disease. Given these differences, it will be
important to apply the emerging molecular tools to determine whether the
phenotypic variability indicates genetic heterogeneity in neonatal-onset Bartter
syndrome. Among the different forms of hereditary renal tubulopathies associated with
hypokalemia, metabolic alkalosis and normotension, two main types of disorders
have been identified: Gitelman disease, which appears to be a homogeneous
post-Henle's loop disorder, and Bartter syndrome, a heterogeneous Henle loop
disorder. A specific gene has been found responsible for Gitelman disease,
encoding the thiazide-sensitive Na-Cl cotransporter (TSC) of the distal
convoluted tubule. From a phenotypic point of view the characteristic findings
of this disease are hypocalciuria, hypomagnesemia and tetanic crises appearing
during childhood or later. Many subjects are asymptomatic. At least three
different genes have been shown to be responsible for Bartter syndrome,
characterized by mutations in the proteins encoding respectively the
bumetanide-sensitive Na-K-2Cl cotransporter, the inwardly-rectifying renal
potassium channel and a renal chloride channel, all protein transports located
in the ascending limb of Henle's loop. Mutations in the first two transport
proteins have been demonstrated in patients with the hypercalciuric forms of
Bartter syndrome associated with nephrocalcinosis (respectively Bartter syndrome
type I and II), who were often born after pregcies complicated by
polyhydramnios and premature delivery. Mutations in the gene encoding a renal
chloride channel were recently recognized in patients with a Henle tubular
defect not associated with nephrocalcinosis (Bartter syndrome type III). Most of
the latter group of patients were normo-hypercalciuric and presented dehydration
and life-threatening hypotension in the first year of life. However, these three
genes do not explain all the patients with Bartter syndrome which unlike
Gitelman disease, appears to be a very heterogeneous disorder. Clearance
studies, especially if done during furosemide and/or hydrochlorothiazide
administration, have been helpful in identifying the site of tubular
involvement. Considering both phenotypic and genotypic data, we propose a
clinical-pathophysiological and molecular approach to diagnose the different
tubulopathies associated with hypokalemic metabolic alkalosis. Bartter syndrome is characterized by renal potassium and chloride loss,
hypokalaemia, hypochloraemic metabolic alkalosis and increased plasma renin
activity along with elevated angiotensin II and hyperaldosteronism. For
diagnosis we conducted biochemical examinations of both amniotic fluid and the
mother's urine. Except for potassium, amniotic fluid electrolytes in a mother
with a fetus with Bartter syndrome were high. Urinary chloride, sodium and
calcium were very low. Thus, the latter parameters may allow prediction of fetal
Bartter syndrome during the prenatal period. Bartter syndromes are defined as a family of inherited recessive autosomal
tubulopathies. They are characterized by hypochloremia, hypokalemia, metabolic
alkalosis associated with potassium renal leakage and normal blood pressure
despite increased plasma renin activity. Three forms of the disease are
identified as followed: 1) Gitelman syndrome or hypocalciuria hypomagnesemia
syndrome is a mild form often discovered in childhood or teenagers in reason of
tetany. It is an homogeneous disorder related to mutations of the genes encoding
the thiazide-sensitive Na-Cl cotransporter located in the distal convoluted
tubule. 2) Antenatal Bartter syndrome with hypercalciuria and nephrocalcinosis
or hyperprostaglandin E syndrome is a severe form, often revealed by hydramnios,
prematurity and growth delay. It is related to mutations of two types of genes
encoding for transporters of Henle's loop: the bumetanide-sensitive
cotransporter Na-K-2Cl (NKCC2) [type I] or the inwardly-rectifying potassium
channel (ROMK) [type II]. 3) the classical form or type III Bartter syndrome,
often revealed by dehydration in the first year of life, is associated with
hypomagnesemia in 20% of cases and normal or increased calciuria. This form is
related to mutations of CLCNKB gene encoding for a chloride channel in Henle's
loop. This classification, in part related to the demonstration of mutations in
the genes encoding for tubular chloride or potassium channels, does not fit all
cases, overlapping syndromes are frequent. Moreover some endocrinological
(diabetes) and neurological (deafness) abnormalities are sometimes associated
with Bartter syndromes. Both phenotypic and genetic approach must help to the
diagnosis of these tubulopathies. Bartter syndrome, which presents clinically with polyuria, urinary potassium
loss, hypokalemia, hypercalciuria, and alkalosis, is an autosomal recessive
disorder with mutations in genes encoding the Na-K-2Cl cotransporter, the
chloride channel CLC-NKB, and the potassium channel ROMK. Prenatal diagnosis of
Bartter syndrome is now possible; however, there are no reports of the placental
pathology associated with fetal Bartter syndrome. We present the placental
pathologic findings in two siblings with fetal Bartter syndrome. Both
pregcies were complicated by polyhydramnios and preterm delivery. The first
pregcy delivered at 30 weeks, and Bartter syndrome was diagnosed in the
perinatal period. The subsequent pregcy required periodic therapeutic
amniocentesis secondary to massive polyhydramnios and delivered at 32 weeks
gestation. The suspicion of fetal Bartter syndrome was very high in this second
pregcy, and the infant was confirmed to have Bartter syndrome subsequently.
Both placentas were large for gestational age, weighing greater than the 95th
percentile. Microscopic examination showed extensive subtrophoblastic basement
membrane mineralization (special stains positive for iron and calcium) in the
chorionic villi. This striking finding was present in both placentas.
Subtrophoblastic mineralization has been described in the literature in
placentas of fetuses with abnormalities including anencephaly, trisomy 21, and
other congenital abnormalities; however, it has also been described in normal
pregcies. Mechanisms of calcification in the placenta are not well
understood, but these striking cases suggest that defects in fetal renal
excretion of ions can lead to dystrophic calcification within the placenta,
particularly in a subtrophoblastic pattern. Bartter-like syndrome encompasses a set of inherited renal tubular disorders
associated with hypokalemic metabolic alkalosis, renal salt wasting,
hyperreninemic hyperaldosteronism, and normal blood pressure. Antenatal Bartter
syndrome, a subtype of Bartter-like syndrome, is characterized by
polyhydramnios, premature delivery, life-threatening episodes of fever and
dehydration during the early weeks of life, growth retardation, hypercalciuria,
and early-onset nephrocalcinosis. Mutations in the bumetanide-sensitive Na-K-2Cl
cotransporter (NKCC2) and ATP-sensitive inwardly rectifying potassium channel
(ROMK) of the thick ascending limb of Henle's loop have been identified in the
antenatal Bartter syndrome. We report the identification of two heterozygous
mutations of the gene for Kir 1.1 (ROMK) from an antenatal Bartter syndrome
patient who presented at birth with mild salt wasting and a biochemical findings
that mimicked primary pseudohypoaldosteronism type 1, such as hyperkalemia and
hyponatremia, and evolved to a relatively benign course. We have identified
amino acid exchanges Arg338Stop and Met357Thr in the gene exon 5 for ROMK by PCR
and direct sequencing. Both mutations alter the C-terminus of the ROMK protein,
and can affect channel function. PURPOSE OF REVIEW: This review describes recent advances in our understanding of
the genetic heterogeneity, pathophysiology and treatment of Bartter syndrome, a
group of autosomal recessive disorders that are characterized by markedly
reduced or absent salt transport by the thick ascending limb of Henle.
Consequently, individuals with Bartter syndrome exhibit renal salt wasting and
lowered blood pressure, hypokalemic metabolic alkalosis and hypercalciuria with
a variable risk of renal stones.
RECENT FINDINGS: Previously, three genes (SLC12A2, the sodium-potassium-chloride
co-transporter; KCNJ1, the ROMK potassium ion channel; ClC-Kb, the basolateral
chloride ion channel) had been identified as causing antenatal and 'classic'
Bartter syndrome. Two additional genes have now been identified. Barttin is a
beta-subunit that is required for the trafficking of CLC-K (both ClC-Ka and
ClC-Kb) channels to the plasma membrane in both the thick ascending limb and the
marginal cells in the scala media of the inner ear that secrete potassium
ion-rich endolymph. Loss-of-function mutations in barttin thus cause Bartter
syndrome with sensorineural deafness. In addition, severe gain-of-function
mutations in the extracellular calcium ion-sensing receptor can result in a
Bartter phenotype because activation of this G protein-coupled receptor inhibits
salt transport in the thick ascending limb (a furosemide-like effect).
SUMMARY: Five genes have been identified as causing Bartter syndrome (types
I-V), with the unifying pathophysiology being the loss of salt transport by the
thick ascending limb. Phenotypic differences in Bartter types I-V relate to the
specific physiological roles of the individual genes in the kidney and other
organ systems. Bartter syndrome is an uncommon tubular disorder inherited as an autosomal
recessive entity. It is associated with hypokalemic metabolic alkalosis with
high renin and aldosterone plasma concentration with low or normal blood
pressure. Recent studies have demonstrated genetic heterogeneity in Bartter
syndrome. Mutations of two genes encoding the Na/K/2Cl cotransporter and
potassium channel ROMK are responsible for clinical features of neonatal Bartter
syndrome. Mutations of gen encoding the chloride channel ClC-Kb is identified as
being causative for the classic Bartter syndrome. And dysfunction of Na/Cl
cotransporter in the distal convoluted renal tubule is described as Gitelman
syndrome. Bartter syndrome is an inherited renal tubular disorder with hypokalemia,
hypochloremic metabolic alkalosis, normal blood pressure with hyper-reninemia
and increased urinary loss of sodium, potassium and chloride. We report an
infant with neonatal Bartter syndrome, who improved with potassium supplements. Bartter syndrome is a rare autosomal recessive, salt-losing disorder
characterized by hypokalemic hypochloremic metabolic alkalosis. A 10-year-old
boy had severe growth retardation (height standard deviation score -8.15). He
had a thin, triangular face, prominent ears and forehead, and big eyes.
Megacystis, bilateral hydroureteronephrosis, and residual urine were detected in
ultrasonography, but there was no vesicoureteral reflux. Lumbosacral magnetic
resoce (MR) showed posterior disc bulging at L4-5. Serum sodium and chloride
levels were normal, but mild hypokalemia was overlooked initially. During
follow-up, hypokalemic hypochloremic metabolic alkalosis developed, with high
urinary chloride and potassium excretion (52 and 43 mEq/L, respectively). The
patient, with renal salt loss, was thought to have classic Bartter syndrome due
to absence of nephrocalcinosis, presence of persistent hypercalciuria and
sensorineural deafness, and presence of relatively mild clinical and laboratory
findings, except polyuria initially. The child was treated with indomethacin,
spironolactone, and oral potassium in addition to growth hormone (GH). During
treatment, he had considerable increase in weight and height compared with the
period of GH therapy only. We present this case because, although growth
retardation is a major feature of Bartter syndrome, associated GH deficiency is
rarely reported in the literature. Diagnosis of Bartter syndrome was made later,
as our patient was followed for megacystis and megaureter secondary to the
neurogenic bladder and GH deficiency initially; and proteinuria associated with
focal segmental glomerulosclerosis responded to treatment for Bartter syndrome. Bartter syndrome is a rare hereditary (autosomal recessive) salt-losing
tubulopathy characterized by hypokalemia, hypochloremia, metabolic alkalosis,
and normal blood pressure with hyperreninemia, The underlying renal abnormality
results in excessive urinary losses of sodium, chloride, and potassium. We
report a case of a four-month-old infant with neonatal Bartter syndrome, who
presented only with status epilepticus. To the best of our present knowledge,
there is no reported case of Bartter syndrome who presented with status
epilepticus. BACKGROUND: Bartter syndrome is a rare autosomal recessive disorder
characterized by hypokalemia, salt loss, and metabolic alkalosis. Short stature
is one of the clinical manifestations in these children. Although polyuria,
polydipsia, hypokalemia, and salt loss may be responsible for growth
retardation, the exact pathogenesis of short stature in Bartter syndrome is not
known.
CASE DIAGNOSIS AND TREATMENT: In this study, we present three children diagnosed
as having Bartter syndrome with short stature and growth hormone (GH)
deficiency. After recombit human growth hormone therapy (rhGH), their growth
velocities were improved.
CONCLUSIONS: These results indicate that GH deficiency may contribute to short
stature in children with Bartter syndrome, and rhGH therapy would be an
excellent adjunctive treatment for short children with this syndrome whose
condition is resistant to conventional therapies in terms of growth. Bartter syndrome is a group of inherited, salt-losing tubulopathies presenting
as hypokalemic metabolic alkalosis with normotensive hyperreninemia and
hyperaldosteronism. Around 150 cases have been reported in literature till now.
Mutations leading to salt losing tubulopathies are not routinely tested in
Indian population. The authors have done the genetic analysis for the first time
in the Bartter syndrome on two cases from India. First case was antenatal
Bartter syndrome presenting with massive polyuria and hyperkalemia. Mutational
analysis revealed compound heterozygous mutations in KCNJ1(ROMK) gene
[p(Leu220Phe), p(Thr191Pro)]. Second case had a phenotypic presentation of
classical Bartter syndrome however, genetic analysis revealed only heterozygous
novel mutation in SLC12A gene p(Ala232Thr). Bartter syndrome is a clinical
diagnosis and genetic analysis is recommended for prognostication and genetic
counseling. OBJECTIVE: Bartter syndrome is a severe inherited tubulopathy characterized by
postnatal salt wasting, severe polyuria, dehydration, failure to thrive and
secondary hyperaldosteronism. Prenatally, the disease is usually discovered
following the onset of severe polyhydramnios in the second trimester. We studied
amniotic fluid aldosterone concentration in Bartter syndrome and in controls.
METHODS: Amniotic fluid aldosterone was assayed by radioimmunoassay. We
undertook a retrospective case-control study based on 36 cases of prenatally
suspected and postnatally confirmed Bartter syndrome (22 with identified
mutations): and 72 gestational age matched controls presenting with
polyhydramnios and 72 without polyhydramnios. Amniotic fluid aldosterone was
compared between the three groups.
RESULTS: The median amniotic fluid aldosterone concentration in the Bartter
syndrome group (90 pg/mL) was not different from that in the controls with
polyhydramnios (90 pg/mL, P = 0.33) or without polyhydramnios (87 pg/mL,
P = 0.41).
CONCLUSION: Amniotic fluid aldosterone assay cannot be used for prenatal
diagnosis of Bartter syndrome. © 2015 John Wiley & Sons, Ltd. Bartter syndrome is a rare heterogeneous group of autosomal-recessive
salt-losing renal tubular disorders that can present in fetal life (antenatal
Bartter syndrome; ABS) as "unexplained" early-onset polyhydramnios, often
associated with growth restriction. Prenatal diagnosis of the condition involves
assessment of amniotic fluid biochemistry in a setting of polyuric
polyhydramnios; with elevated chloride levels considered a consistent and
diagnostic finding. Other amniotic fluid biochemical markers have been
described, notably increased aldosterone levels, and low total protein levels.
NOVEL INSIGHT: Antenatal Bartter syndrome is a heterogeneous group of renal
disorders. While certain biochemical features in amniotic fluid might heighten
suspicion, final diagnosis can only be made in the postnatal setting. In the
setting of unexplained severe polyhydramnios, clinicians should continue to
entertain the diagnosis of antenatal Bartter Syndrome and maintain neonatal
surveillance, even if amniotic fluid markers do not support the diagnosis. Bartter syndrome is a rare inherited defect in the thick ascending limb of the
loop of Henle. It is characterized by low potassium levels (hypokalaemia),
increased blood pH (alkalosis) and normal to low blood pressure. There are three
types of Bartter syndrome: neonatal, the classic type and Gitelman syndrome.
Nephropathic cystinosis is an autosomal recessive disorder characterized by
accumulation of free cystine in lysosomes due to disorder of lysosomal transport
that can lead to end stage renal failure within 10 years and multiorgan
impairment. We report a 5 year 9 month old child with Bartter syndrome
associated with nephropathic cystinosis, hypothyroidism and rickets. Hitherto,
only a handful of similar cases have been reported in the literature. Bartter syndrome Type III is a rare autosomal recessive disorder resulting from
an inherited defect in the thick ascending limb of the loop of henle of the
nephrons in kidney. The typical clinical manifestations in childhood are failure
to thrive and recurrent episodes of vomiting. Typical laboratory findings which
help in the diagnosis are hypokalemic metabolic alkalosis, hypomagnesemia and
hypercalciuria. We report a case of Type III Bartter syndrome not responding to
repeated conventional treatment of failure to thrive. Bartter's syndrome is an autosomal recessive renal tubular disorder
characterized by hypokalemia, hypochloremia, metabolic alkalosis, and
hyperreninemia with normal blood pressure. Bartter's syndrome is associated with
hypercalciuria and nephrocalcinosis. Amelogenesis imperfecta (AI) is a group of
hereditary disorders that affect dental enamel. AI could be part of several
syndromes. The enamel renal syndrome is the association of AI and
nephrocalcinosis. We report two patients of AI with Bartter's syndrome. Bartter syndrome is an autosomal recessive disorder caused by gene mutations
that involve hypokalaemia, hypochloraemia and metabolic alkalosis along with
raised serum renin, hyperaldosteronism and normal blood pressure. We report two
cases of neonatal Bartter syndrome. Case 1 was a product of non-consanguineous
marriage and mother had unexplained polyhydramnios in pregcy while case 2 was
a product of consanguineous marriage. Both cases were diagnosed based on
hypokalaemia, hypochloraemia and metabolic alkalosis along with elevated serum
renin and aldosterone levels. Case 1 positively responded to indomethacin while
case 2 had Protein C and S deficiency and sepsis as coexisting diseases and thus
could not be given indomethacin and expired. Regular antenatal visits can help
in diagnosis of the syndrome particularly if unexplained poly hydramniosis
investigated . Bartter syndrome is a rare heterogeneous disease characterised by a deficiency
in sodium and chloride absorption. Gain-of-function mutations in the CASR gene
have been described in some patients with Bartter syndrome associated with
hypocalcaemia and hypercalciuria. We describe a case of adult-onset Bartter
syndrome with hypocalcaemia severe enough to cause osteomalacia.
LEARNING POINTS: Bartter syndrome is one of the rare heterogenous diseases that
present with electrolyte disturbances.Bartter syndrome type 5 also causes
hypercalciuria which is not severe enough to cause osteomalacia.Patients with
adult-onset Bartter syndrome should be screened promptly for osteomalacia to
prevent pathological fractures and consequent complications. Bartter syndrome is a rare disorder characterized by reduced sodium chloride
transport in the distal nephrons of the kidney. Its clinical features are renal
salt wasting, hypokalemic metabolic alkalosis, elevated renin and aldosterone
levels with normal or low blood pressure, polyuria, hypercalciuria and
malnutrition. The pathophysiologic and biochemical changes in these patients
should be kept in mind when considering anaesthetic management. This case report
describes our management in a nineteen months old, 3.6 kg weight male child with
Bartter's syndrome who underwent elective repair of hiatal hernia and
gastrostomy. Bartter syndrome is an autosomal recessive disorder manifested by a defect in
sodium-potassium-chloride transport in the thick ascending limb of Henle with
different genetic origins and molecular pathophysiology. Bartter syndrome
usually a common disease in children and in early infancy presented with
persistent polyuria and associated with dehydration, electrolyte imbalance, and
failure to thrive. Though prompt diagnosis and proper treatment of Bartter
syndrome may improve the outcome, some children will progress to renal failure.
We report a case of a 6 days-old male infant who was admitted in Neonatal
Intensive Care Unit, Bangabandhu Sheikh Mujib Medical University, Dhaka,
Bangladesh on 26 April 2018 for prematurity and low birth weight. On subsequent
follow up he developed electrolyte imbalance and failure to thrive. Laboratory
studies revealed hyponatremia, hypochloremic metabolic alkalosis with severe
hypokalemia. When excessive chloride losses appear to be renal in origin and the
patient has normal blood pressure and high levels of serum renin and aldosterone
were considered as Bartter syndrome. Molecular genetic studies are indicated to
identify the primary genetic defect. Author information:
(1)Department of General Pediatrics, University Hospital Münster, Münster,
Germany. Electronic address: [email protected].
(2)Department of Nephrology, Radboud University Medical Center, Nijmegen, The
Netherlands.
(3)Pediatric Nephrology, Hospital Universitari Vall d'Hebron, Universitat
Autonoma de Barcelona, Barcelona, Spain.
(4)Université Claude Bernard Lyon 1, Lyon, France.
(5)Department of Medicine (DIMED), Nephrology, Dialysis, Transplantation,
University of Padova, Padua, Italy.
(6)Division of Nephrology, Department of Translational Medical Sciences, School
of Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy.
(7)Division of Nephrology, Department of Pediatric Subspecialties, Bambino Gesù
Children's Hospital IRCCS, Rome, Italy.
(8)Department of General Pediatrics, University Hospital Münster, Münster,
Germany.
(9)Fetal Medicine Centre, Southend University Hospital NHS Foundation Trust,
Essex, UK.
(10)Department of Renal Medicine, University College London, London, United
Kingdom.
(11)London, UK.
(12)Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris,
Centre d'Investigation Clinique, Paris, France; Centre de Référence des Maladies
Rénales Héréditaires de l'Enfant et de l'Adulte, Paris, France.
(13)Department of Renal Medicine, University College London, London, United
Kingdom; Department of Pediatric Nephrology, Great Ormond Street Hospital for
Children NHS Foundation Trust, London, UK. |
Can bergapten cause phototoxicity? | Yes, phototoxicity is a side effect of bergapten. | Bergapten is a natural furocoumarin, also known as 5-methoxypsoralen, and its
medicinal value has been paid more and more attention. By sorting out the
pharmacological literature of bergapten, we found that bergapten has a wide
range of pharmacological effects, including neuroprotection, organ protection,
anticancer, antiinflammatory, antimicrobial, and antidiabetes effects.
However，bergapten has complex impacts on the hepatic metabolic enzyme. Moreover,
pharmacokinetic studies showed that bergapten has higher absolute
bioavailability and can cross the blood-brain barrier and has a great potential
for treating brain disease, but the mechanism needs further clarification to
make greater use of its ability to treat brain diseases. Furthermore, the
phototoxicity of bergapten combined with ultraviolet light has always been
mentioned. In view of its wide range of pharmacological activities, bergapten is
expected to be a potential drug candidate for the treatment of diabetes and
diabetes-induced osteoporosis, epilepsy, Alzheimer's disease, depression, and
cancer. However, further studies are needed to elucidate its molecular
mechanisms and targets. The phototoxicity of bergapten as a side effect should
be further avoided. On the other hand, the photoactivation of bergapten in the
anticancer aspect can be better utilized. |
Which syndromes are caused by LAMA1 mutations? | Poretti-Boltshauser and Joubert syndromes | BACKGROUND: High myopia with alopecia areata in the occipital region has been
observed in patients with Knobloch syndrome caused by COL18A1 mutations. This
study investigated other possible genetic causes of high myopia in patients with
alopecia areata in the cranial midline.
METHODS: Six patients with early onset high myopia and alopecia areata in the
cranial midline were recruited. Targeted high-throughput sequencing was
performed on the proband's DNA to detect potential pathogenic variants.
Cosegregation analysis was performed for available family members. Minigene
assay and RNA Sequencing were used to validate the abnormality of possible
splicing change and gross deletion. Ophthalmological and neuroimaging
examinations were performed.
RESULTS: Eight novel and one known loss-of-function mutants were detected in all
six patients, including a gross deletion detected by RNA sequencing. Four
COL18A1 mutants in three patients with scalp leisure in the occipital region;
and five LAMA1 mutations in three patients with scalp leisure in the parietal
region. Further assessments indicated that patients with COL18A1 mutations had
Knobloch syndrome, and the patients with LAMA1 mutations had Poretti-Boltshauser
syndrome.
CONCLUSION: Our study found that early onset high myopia with midline alopecia
areata could be caused not only by mutations of the COL18A1 gene but also by
mutations in the LAMA1 gene. To our knowledge, we are the first to observe scalp
defects in patients with LAMA1 mutations. High myopia with alopecia areata in
the cranial midline could be treated as an early diagnostic clue for
ophthalmologists to consider the two kinds of rare diseases. Paediatric neurology syndromes are a broad and complex group of conditions with
a large spectrum of clinical phenotypes. Joubert syndrome is a genetically
heterogeneous neurological ciliopathy syndrome with molar tooth sign as the
neuroimaging hallmark. We reviewed the clinical, radiological and genetic data
for several families with a clinical diagnosis of Joubert syndrome but negative
genetic analysis. We detected biallelic pathogenic variants in LAMA1, including
novel alleles, in each of the four cases we report, thereby establishing a firm
diagnosis of Poretti-Boltshauser syndrome. Analysis of brain MRI revealed
cerebellar dysplasia and cerebellar cysts, associated with Poretti-Boltshauser
syndrome and the absence of typical molar tooth signs. Using large UK patient
cohorts, the relative prevalence of Joubert syndrome as a cause of intellectual
disability was 0.2% and of Poretti-Boltshauser syndrome was 0.02%. We conclude
that children with congenital brain disorders that mimic Joubert syndrome may
have a delayed diagnosis due to poor recognition of key features on brain
imaging and the lack of inclusion of LAMA1 on molecular genetic gene panels. We
advocate the inclusion of LAMA1 genetic analysis on all intellectual disability
and Joubert syndrome gene panels and promote a wider awareness of the clinical
and radiological features of these syndromes. |
What is the use of Lactin-V? | Lactin-V after treatment with vaginal metronidazole resulted in a significantly lower incidence of recurrence of bacterial vaginosis and can be used for bacterial vaginosis. Lactin-V after treatment for cystitis was associated with a reduction in recurrent UTI. | BACKGROUND: Bacterial vaginosis is a very common vaginal infection. The lack of
endogenous lactobacilli and overgrowth of pathogens facilitate numerous
gynecological complications.
METHODS: A phase I dose-ranging safety trial tested the safety, tolerability,
and acceptability of Lactobacillus crispatus CTV-05 (LACTIN-V) administered by
vaginal applicator. Twelve healthy volunteers were enrolled in 3 blocks of 4 (5
x 10, 1 x 10, and 2 x 10 cfu/dose). Each block was randomized in a 3:1 ratio of
active product to placebo. Participants used study product for 5 consecutive
days, returned for follow-up on days 7 and 14, and had phone interviews on days
2 and 35.
RESULTS: All 12 participants took 5 doses and completed study follow-up.Overall,
45 adverse events (AEs) occurred, of which 31 (69%) were genitourinary (GU) AEs.
GU AEs appeared evenly distributed between the 3 treatment blocks and between
LACTIN-V and placebo arms. The most common GU AEs were vaginal discharge in 5
subjects (42%), abdominal pain in 4 subjects (33%), metrorrhagia in 4 subjects
(33%), vulvovaginitis in 4 subjects (33%), vaginal candidiasis in 3 subjects
(25%), and vaginal odor in 3 subjects (25%). Forty-one (91%) AEs were mild
(grade 1) in severity. All 4 moderate AEs (grade 2) were unrelated to product
use. No grade 3 or 4 AEs or serious adverse events (SAE) occurred. Laboratory
parameters and colposcopy findings were within normal limits or clinically
insignificant. The product was well-tolerated and accepted.
CONCLUSION: All 3 dose levels of LACTIN-V appeared to be safe and acceptable in
healthy volunteers. BACKGROUND: Bacterial vaginosis (BV) is a common vaginal infection caused by a
lack of endogenous lactobacilli and overgrowth of pathogens that frequently
recurs following antibiotic treatment.
METHODS: A phase 2a study assessed colonization efficiency, safety,
tolerability, and acceptability of Lactobacillus crispatus CTV-05 (LACTIN-V)
administered by a vaginal applicator. Twenty-four women with BV were randomized
in a 3:1 ratio of active product to placebo. Participants used LACTIN-V at 2 ×
10 colony-forming units (cfu)/dose or placebo for 5 initial consecutive days,
followed by a weekly application over 2 weeks. They returned for follow-up on
Days 10 and 28.
RESULTS: Sixty-one percent of the 18 women randomized to the LACTIN-V group were
colonized with L. crispatus CTV-05 at Day 10 or Day 28. Among LACTIN-V users
with complete adherence to the study regimen, 78% were colonized at Day 10 or
Day 28. Of the 120 adverse events (AEs) that occurred, 108 (90%) and 12 (10%)
were of mild and moderate severity, respectively. AEs were evenly distributed
between the LACTIN-V and placebo group. Of the total AEs, 93 (78%) were
genitourinary in origin. The most common genitourinary AEs included vaginal
discharge (46%), abdominal pain (46%), dysuria (21%), pollakiuria (21%), vaginal
odor (21%), and genital pruritus (17%). No grade 3 or 4 AEs or serious AEs
occurred and no deep epithelial disruption was seen during colposcopic
evaluation. The product was well tolerated and accepted.
CONCLUSIONS: LACTIN-V colonized well, and was safe and acceptable in women
treated for BV. BACKGROUND: Urinary tract infections (UTIs) are common among women and
frequently recur. Depletion of vaginal lactobacilli is associated with UTI risk,
which suggests that repletion may be beneficial. We conducted a double-blind
placebo-controlled trial of a Lactobacillus crispatus intravaginal suppository
probiotic (Lactin-V; Osel) for prevention of recurrent UTI in premenopausal
women.
METHODS: One hundred young women with a history of recurrent UTI received
antimicrobials for acute UTI and then were randomized to receive either Lactin-V
or placebo daily for 5 d, then once weekly for 10 weeks. Participants were
followed up at 1 week and 10 weeks after intervention and for UTIs; urine
samples for culture and vaginal swabs for real-time quantitative 16S ribosomal
RNA gene polymerase chain reaction for L. crispatus were collected.
RESULTS: Recurrent UTI occurred in 7/48 15% of women receiving Lactin-V compared
with 13/48 27% of women receiving placebo (relative risk [RR], .5; 95%
confidence interval, .2-1.2). High-level vaginal colonization with L. crispatus
(≥10(6) 16S RNA gene copies per swab) throughout follow-up was associated with a
significant reduction in recurrent UTI only for Lactin-V (RR for Lactin-V, .07;
RR for placebo, 1.1; P < .01).
CONCLUSIONS: Lactin-V after treatment for cystitis is associated with a
reduction in recurrent UTI. Larger efficacy trials of this novel preventive
method for recurrent UTI are warranted. CLINICAL TRIALS REGISTRATION.
NCT00305227. BACKGROUND: Bacterial vaginosis affects 15 to 50% of women of reproductive age,
and recurrence is common after treatment with an antibiotic agent. The high
incidence of recurrence suggests the need for new treatments to prevent
recurrent bacterial vaginosis.
METHODS: We conducted a randomized, double-blind, placebo-controlled, phase 2b
trial to evaluate the ability of Lactobacillus crispatus CTV-05 (Lactin-V) to
prevent the recurrence of bacterial vaginosis. Women 18 to 45 years of age who
had received a diagnosis of bacterial vaginosis and who had completed a course
of vaginal metronidazole gel as part of the eligibility requirements were
randomly assigned, in a 2:1 ratio, to receive vaginally administered Lactin-V or
placebo for 11 weeks; follow-up occurred through week 24. The primary outcome
was the percentage of women who had a recurrence of bacterial vaginosis by week
12.
RESULTS: A total of 228 women underwent randomization: 152 to the Lactin-V group
and 76 to the placebo group; of these participants, 88% in the Lactin-V group
and 84% in the placebo group could be evaluated for the primary outcome. In the
intention-to-treat population, recurrence of bacterial vaginosis by week 12
occurred in 46 participants (30%) in the Lactin-V group and in 34 participants
(45%) in the placebo group (risk ratio after multiple imputation for missing
responses, 0.66; 95% confidence interval [CI], 0.44 to 0.87; P = 0.01). The risk
ratio for recurrence by week 24 (also calculated with multiple imputation for
missing responses) was 0.73 (95% CI, 0.54 to 0.92). At the 12-week visit, L.
crispatus CTV-05 was detected in 79% of participants in the Lactin-V group. The
percentage of participants who had at least one adverse event related to
Lactin-V or placebo by week 24 did not differ significantly between the groups.
The percentage of participants with local or systemic adverse events was similar
in the two groups.
CONCLUSIONS: The use of Lactin-V after treatment with vaginal metronidazole
resulted in a significantly lower incidence of recurrence of bacterial vaginosis
than placebo at 12 weeks. (Funded by the National Institutes of Health;
ClinicalTrials.gov number, NCT02766023.). |
What is Congo red agar plates used for? | Congo red agar plates are used as a canonical indicator of biofilm-formation ability. Culture on Congo red agar plates in which slime-producing strains form black colonies, while nonslime-forming ones develop red colonies. | Staphylococcus epidermidis is a frequent pathogen in infections associated with
orthopedic implants. We studied 123 S. epidermidis strains from infections
related to orthopedic implants, as regards their ability to express a factor of
virulence, namely the slime, an extracellular polysaccharide, which mediates
adherence to implants and bacterial colonization. The slime-producing ability
was determined by PCR detection of icaA and icaD genes responsible for slime
synthesis, and by culture on Congo red agar plates in which slime-producing
strains form black colonies, while nonslime-forming ones develop red colonies.
56% of the S. epidermidis isolates were icaA- icaD-positive and grew to become
black colonies. In the evaluation of the distribution of slime-forming strains
in different sites and types of implants, we found a slight, but not
statistically significant, increase in slime-forming strains in total joint
prostheses, where tissue compression near the articular faces can form niches in
which bacteria crowd, sheltered by the slime. Our findings confirm the role of
ica genes as a virulence marker in the pathogenesis of implant-associated
orthopedic infections. However, they do not show the existence of a higher
frequency of slime-positive strains in a specific type of implant. OBJECTIVES: Biofilm formation is one of the important features of Staphylococcus
epidermidis, particularly in nosocomial infections. We aimed to investigate the
biofilm production by phenotypic methods and the presence of ica genes in S
epidermidis.
METHODS: A total of 41 S epidermidis isolates were recovered from different
clinical specimens. Biofilm formation was evaluated by microtiter plate, tube
method and Congo red agar method. The presence of icaA and icaD genes was
investigated by PCR. Validity of methods (sensitivity and specificity), and
metrics for test performance (positive/negative predictive value, and
positive/negative likelihood ratio) were determined.
RESULTS: By both microtiter plate and tube method, 53.6% of S epidermidis
isolates were able to produce biofilm, whilst only 24.4% of isolates provided a
biofilm phenotype on Congo red agar plates. icaA and icaD genes were found in
100% and 95.1% of isolates, respectively. Biofilm phenotypes accounted for 4.8%
by microtiter plate assay, despite the absence of the ica gene. Congo red agar
and PCR exhibited a lower sensitivity (18% and 45.5%, respectively) for
identifying the biofilm phenotype in comparison to microtiter plate.
CONCLUSION: The microtiter plate method remains generally a better tool to
screen biofilm production in S epidermidis. In addition, the ability of S
epidermidis to form biofilm is not always dependent on the presence of ica
genes, highlighting the importance of ica-independent mechanisms of biofilm
formation. The use of reliable methods to specifically detect biofilms can be
helpful to treat the patients affected by such problematic bacteria. Salmonella enterica is one of the pathogens that is frequently identified as the
cause of fresh produce-related outbreaks. Biofilm formation is a factor that can
contribute to pathogen survival on produce surface. The goal of our current
research was to investigate the survival of five S. enterica strains
representing different serotypes (i.e., Typhimurium, Enteritidis, Daytona,
Poona, and Newport) on whole mini cucumbers stored at refrigeration (4°C) and
room temperature (22°C). We also determined the strains survival on glass slides
and in phosphate-buffered saline at 4 and 22°C, as well as the ability to form
biofilms on a solid-liquid interphase. A rapid decrease in cell density (>4-log
reduction over 8 days) of all five tested strains was observed on glass slides,
while a slower die-off (<1-log reduction in 8 days) was observed in PBS. No
significant difference in the die-off rate was observed among the five strains
at 4 or 22°C. The die-off rate on the surface of mini cucumbers at 4°C was
significantly slower ( P < 0.02) for Salmonella Enteritidis LMFS-S-JF-005
compared with the remaining four strains. At 22°C, Salmonella Poona S306 was
able to grow by more than 1.5 log units on whole mini cucumbers over a period of
8 days, while the cell density of the other four strains remained at the same
level compared with day 0. At this temperature, Salmonella Poona S306 was also
able to form significantly stronger biofilms on a solid-liquid interphase ( P <
0.01) and was the only strain that presented a red, dry, and rough morphotype on
Congo red agar plates, indicating the formation of both curli fimbriae and
cellulose. These results revealed that the fate of Salmonella on mini cucumbers
is strain specific, which highlighted the need for tailored mitigation
strategies, such as the effective control of temperature and moisture for
limiting the survival or growth of high-risk Salmonella strains between harvest
and consumption of fresh produce. INTRODUCTION: Febrile neutropenia (FN) is the evolution of fever in a patient
with neutropenia over 38.0°C. Neutropenia is diagnosed when absolute neutrophil
count (ANC) <1500 cells/µL. FN represents a common complication of cancer
treatment. Hence, it is featured to be a major cause of morbidity and mortality
in cancer patients. Staphylococcus aureus is one of the most important
microorganisms isolated from the blood of febrile neutropenic patients.
Infections caused by S. aureus range from mild to life-threatening diseases.
Biofilm production by S. aureus is one of the most significant virulence factors
of the bacterium as it prevents the penetration of antibiotics. Recently, it has
been shown that S. aureus carries the ica operon responsible for biofilm
production. The aim of the work is to determine a genotypic characterization
that includes not only the detection of icaA and icaD genes in S. aureus but
also the determination of their relation to clinical and microbiological
features. Empiric antibacterial treatment was recommended for cancer patients
receiving chemotherapy.
MATERIALS AND METHODS: The relation between the presence of icaA and icaD and
biofilm production was determined in a collection of 66 S. aureus samples from
febrile neutropenic patients. Biofilm-forming ability was tested on Congo Red
agar plates. Also, the effect of the most sensitive antibiotics on the bacterial
cells was determined by an electron microscope.
RESULTS: Of the bacterial samples, 48 were biofilm-productive and 18 were
non-biofilm productive. For the biofilm productive bacteria, 37.5% were positive
for icaA, 22.9% were positive for icaD and 10.4% were positive for both.
Linezolid was the most effective antibiotic and it is highly recommended for the
treatment of febrile neutropenia caused by biofilm-productive S. aureus. Severe
changes were found on the bacterial cell after being treated with Linezolid. The
icaA and icaD genes were present in only 50% of biofilm-productive bacteria.
CONCLUSION: The ica operon is present in only 50% of biofilm-productive S.
aureus and Linezolid is the best antibiotic against these bacteria. |
What is the protein that is truncated to produce progerin? | The truncated lamin A protein produced "progerin | Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder that is
characterized by dramatic premature aging and accelerated cardiovascular
disease. HGPS is almost always caused by a de novo point mutation in the lamin A
gene (LMNA) that activates a cryptic splice donor site, producing a truncated
mutant protein termed "progerin." WT prelamin A is anchored to the nuclear
envelope by a farnesyl isoprenoid lipid. Cleavage of the terminal 15 aa and the
farnesyl group releases mature lamin A from this tether. In contrast, this
cleavage site is deleted in progerin. We hypothesized that retention of the
farnesyl group causes progerin to become permanently anchored in the nuclear
membrane, disrupting proper nuclear scaffolding and causing the characteristic
nuclear blebbing seen in HGPS cells. Also, we hypothesized that blocking
farnesylation would decrease progerin toxicity. To test this hypothesis, the
terminal CSIM sequence in progerin was mutated to SSIM, a sequence that cannot
be farnesylated. SSIM progerin relocalized from the nuclear periphery into
nucleoplasmic aggregates and produced no nuclear blebbing. Also, blocking
farnesylation of authentic progerin in transiently transfected HeLa, HEK 293,
and NIH 3T3 cells with farnesyltransferase inhibitors (FTIs) restored normal
nuclear architecture. Last, treatment of both early- and late-passage human HGPS
fibroblasts with FTIs resulted in significant reductions in nuclear blebbing.
Our results suggest that treatment with FTIs represents a potential therapy for
patients with HGPS. Hutchinson-Gilford progeria syndrome (HGPS) is caused by the production of a
truncated prelamin A, called progerin, which is farnesylated at its carboxyl
terminus. Progerin is targeted to the nuclear envelope and causes misshapen
nuclei. Protein farnesyltransferase inhibitors (FTI) mislocalize progerin away
from the nuclear envelope and reduce the frequency of misshapen nuclei. To
determine whether an FTI would ameliorate disease phenotypes in vivo, we created
gene-targeted mice with an HGPS mutation (LmnaHG/+) and then examined the effect
of an FTI on disease phenotypes. LmnaHG/+ mice exhibited phenotypes similar to
those in human HGPS patients, including retarded growth, reduced amounts of
adipose tissue, micrognathia, osteoporosis, and osteolytic lesions in bone.
Osteolytic lesions in the ribs led to spontaneous bone fractures. Treatment with
an FTI increased adipose tissue mass, improved body weight curves, reduced the
number of rib fractures, and improved bone mineralization and bone cortical
thickness. These studies suggest that FTIs could be useful for treating humans
with HGPS. Mutations in the lamin A/C (LMNA) gene that cause Hutchinson-Gilford progeria
syndrome (HGPS) lead to expression of a protein called progerin with 50 amino
acids deleted from the tail of prelamin A. In cells from patients with HGPS,
both the amount and distribution of heterochromatin are altered. We designed in
vitro assays to ask whether such alterations might reflect changes in chromatin,
DNA and/or histone binding properties of progerin compared to wild-type lamin
C-terminal tails. We show that progerin tail has a reduced DNA/chromatin binding
capacity and modified trimethylated H3K27 binding pattern, offering a molecular
mechanism for heterochromatin alterations related to HGPS. Progerin is a truncated form of lamin A. It is identified in patients with
Hutchinson-Gilford progeria syndrome (HGPS), a disease characterized by
accelerated aging. The contribution of progerin toward aging has been shown to
be related to increased DNA damages. Since aging is one major risk factor for
carcinogenesis, and genomic instability is a hallmark of maligt cancers, we
investigated the expression of progerin in human cancer cells, and whether its
expression contributes to carcinogenesis. Using RT-PCR and Western blotting, we
detected the expression of progerin in prostate PC-3, DU145 and LNCaP cells at
mRNA and protein levels. Ectopic progerin expression did not cause cellular
senescence in PC-3 or MCF7 cells. PC-3 cells progerin transfectants were
sensitized to DNA damage agent camptothecin (CPT); and persistent DNA damage
responses were observed, which might be caused by progerin induced defective DNA
damage repair. In addition, progerin transfectants were more tumorigenic in vivo
than vector control cells. Our study for the first time describes the expression
of progerin in a number of human cancer cell lines and its contributory role in
tumorigenesis. Anti-ageing products are of a great importance in cosmetic fields. However, even
if numerous strategies have been proposed to fight against skin ageing or to
minimize its aesthetic impact since the beginning of the 'scientific
cosmetology' era, the products basing their efficacy on the observation of
pathological situations are rare. The most obvious pathology linked to the
ageing of skin (notably) consists in the Hutchinson-Gilford Progeria Syndrome
(HGPS), a rare disorder characterized by accelerated ageing and early death. In
this disease the lamin A, a protein participating (with others lamins) in the
formation of the nuclear lamina and implicated in nuclear stability, chromatin
structure and gene expression, is present in a truncated version called
progerin. In this study, we have examined the lactate and the progerin
production of human normal cutaneous cells issued from subjects of different
ages. Using a sensitive and specific progerin ELISA assay developed in house, we
so provide the first quantitative demonstration of an increased progerin
expression and lactate production in skin during ageing. Moreover, we have also
demonstrated that in the selected experimental conditions, it was possible to
down-regulate the progerin production of aged cells by using an algae extract.
As this extract, an Alaria esculenta extract, could be used in cosmetic
formulations, we suggest that a better understanding of the skin pathologies
could be a useful tool in developing efficient active compounds, attractive for
but not limited to cosmetic purposes. Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder because
of a LMNA gene mutation that produces a mutant lamin A protein (progerin).
Progerin also has been correlated to physiological aging and related diseases.
However, how progerin causes the progeria remains unknown. Here, we report that
the large subunit (RFC1) of replication factor C is cleaved in HGPS cells,
leading to the production of a truncated RFC1 of ~ 75 kDa, which appears to be
defective in loading proliferating cell nuclear antigen (PCNA) and pol δ onto
DNA for replication. Interestingly, the cleavage can be inhibited by a serine
protease inhibitor, suggesting that RFC1 is cleaved by a serine protease.
Because of the crucial role of RFC in DNA replication, our findings provide a
mechanistic interpretation for the observed early replicative arrest and
premature aging phenotypes of HPGS and may lead to novel strategies in HGPS
treatment. Furthermore, this unique truncated form of RFC1 may serve as a
potential marker for HGPS. Farnesylated prelamin A is a processing intermediate produced in the lamin A
maturation pathway. Accumulation of a truncated farnesylated prelamin A form,
called progerin, is a hallmark of the severe premature ageing syndrome,
Hutchinson-Gilford progeria. Progerin elicits toxic effects in cells, leading to
chromatin damage and cellular senescence and ultimately causes skin and
endothelial defects, bone resorption, lipodystrophy and accelerated ageing.
Knowledge of the mechanism underlying prelamin A turnover is critical for the
development of clinically effective protein inhibitors that can avoid
accumulation to toxic levels without impairing lamin A/C expression, which is
essential for normal biological functions. Little is known about specific
molecules that may target farnesylated prelamin A to elicit protein degradation.
Here, we report the discovery of rapamycin as a novel inhibitor of progerin,
which dramatically and selectively decreases protein levels through a mechanism
involving autophagic degradation. Rapamycin treatment of progeria cells lowers
progerin, as well as wild-type prelamin A levels, and rescues the chromatin
phenotype of cultured fibroblasts, including histone methylation status and BAF
and LAP2alpha distribution patterns. Importantly, rapamycin treatment does not
affect lamin C protein levels, but increases the relative expression of the
prelamin A endoprotease ZMPSTE24. Thus, rapamycin, an antibiotic belonging to
the class of macrolides, previously found to increase longevity in mouse models,
can serve as a therapeutic tool, to eliminate progerin, avoid farnesylated
prelamin A accumulation, and restore chromatin dynamics in progeroid
laminopathies. Mutations in the lamin A/C gene that cause Hutchinson-Gilford progeria syndrome
lead to expression of a truncated, permanently farnesylated prelamin A variant
called progerin. Blocking farnesylation leads to an improvement in the abnormal
nuclear morphology observed in cells expressing progerin, which is associated
with a re-localization of the variant protein from the nuclear envelope to the
nuclear interior. We now show that a progerin construct that cannot be
farnesylated is localized primarily in intranuclear foci and that its
diffusional mobility is significantly greater than that of farnesylated progerin
localized predomitly at the nuclear envelope. Expression of non-farnesylated
progerin in transfected cells leads to a redistribution of lamin A and lamin C
away from the nuclear envelope into intranuclear foci but does not significantly
affect the localization of endogenous lamin B1 at nuclear envelope. There is a
similar redistribution of lamin A and lamin C into intranuclear foci in
transfected cells expressing progerin in which protein farnesylation is blocked
by treatment with a protein farnesyltransferase inhibitor. Blocking
farnesylation of progerin can lead to a redistribution of normal A-type lamins
away from the inner nuclear envelope. This may have implications for using drugs
that block protein prenylation to treat children with Hutchinson-Gilford
progeria syndrome. These findings also provide additional evidence that A-type
and B-type lamins can form separate microdomains within the nucleus. Hutchinson-Gilford progeria syndrome (HGPS, OMIM 176670) is a rare disorder
characterized by segmental accelerated aging and early death from coronary
artery disease or stroke. Nearly 90% of HGPS sufferers carry a G608G mutation
within exon 11 of LMNA, producing a truncated form of prelamin A, referred to as
"progerin". Here, we report the isolation of naïve multipotent skin-derived
precursor (SKP) cells from dermal fibroblast cultures from HGPS donors. These
cells form spheres and express the neural crest marker, nestin, in addition to
the multipotent markers, OCT4, Sox2, Nanog and TG30; these cells can self-renew
and differentiate into smooth muscle cells (SMCs) and fibroblasts. The SMCs
derived from the HGPS-SKPs accumulate nuclear progerin with increasing passages.
A subset of the HGPS-naïve SKPs express progerin in vitro and in situ in HGPS
skin sections. This is the first in vivo evidence that progerin is produced in
adult stem cells, and implies that this protein could induce stem cells
exhaustion as a mechanism contributing to aging. Our study provides a basis on
which to explore therapeutic applications for HGPS stem cells and opens avenues
for investigating the pathogenesis of other genetic diseases. Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) resets
their identity back to an embryonic age and, thus, presents a significant hurdle
for modeling late-onset disorders. In this study, we describe a strategy for
inducing aging-related features in human iPSC-derived lineages and apply it to
the modeling of Parkinson's disease (PD). Our approach involves expression of
progerin, a truncated form of lamin A associated with premature aging. We found
that expression of progerin in iPSC-derived fibroblasts and neurons induces
multiple aging-related markers and characteristics, including dopamine-specific
phenotypes such as neuromelanin accumulation. Induced aging in PD iPSC-derived
dopamine neurons revealed disease phenotypes that require both aging and genetic
susceptibility, such as pronounced dendrite degeneration, progressive loss of
tyrosine hydroxylase (TH) expression, and enlarged mitochondria or
Lewy-body-precursor inclusions. Thus, our study suggests that progerin-induced
aging can be used to reveal late-onset age-related disease features in
hiPSC-based disease models. Hutchinson-Gilford progeria syndrome (HGPS, OMIM 176670) is a rare multisystem
childhood premature aging disorder linked to mutations in the LMNA gene. The
most common HGPS mutation is found at position G608G within exon 11 of the LMNA
gene. This mutation results in the deletion of 50 amino acids at the
carboxyl-terminal tail of prelamin A, and the truncated protein is called
progerin. Progerin only undergoes a subset of the normal post-translational
modifications and remains permanently farnesylated. Several attempts to rescue
the normal cellular phenotype with farnesyltransferase inhibitors (FTIs) and
other compounds have resulted in partial cellular recovery. Using proteomics, we
report here that progerin induces changes in the composition of the HGPS nuclear
proteome, including alterations to several components of the protein degradation
pathways. Consequently, proteasome activity and autophagy are impaired in HGPS
cells. To restore protein clearance in HGPS cells, we treated HGPS cultures with
sulforaphane (SFN), an antioxidant derived from cruciferous vegetables. We
determined that SFN stimulates proteasome activity and autophagy in normal and
HGPS fibroblast cultures. Specifically, SFN enhances progerin clearance by
autophagy and reverses the phenotypic changes that are the hallmarks of HGPS.
Therefore, SFN is a promising therapeutic avenue for children with HGPS. Hutchinson-Gilford progeria syndrome (HGPS, OMIM 176670) is a rare premature
aging disorder that leads to death at an average age of 14.7 years due to
myocardial infarction or stroke. The most common mutation in HGPS is at position
G608G (GGC>GGT) within exon 11 of the LMNA gene. This mutation results in the
deletion of 50 amino acids at the carboxyl-terminal tail of prelamin A,
producing a truncated farnesylated protein called progerin. Lamins play
important roles in the organization and structure of the nucleus. The nuclear
build-up of progerin causes severe morphological and functional changes in
interphase HGPS cells. In this study, we investigated whether progerin elicits
spatiotemporal deviations in mitotic processes in HGPS fibroblasts. We analyzed
the nuclear distribution of endogenous progerin during mitosis in relation to
components of the nuclear lamina, nuclear envelope (NE) and nuclear pores. We
found that progerin caused defects in chromosome segregation as early as
metaphase, delayed NE reformation and trapped lamina components and inner NE
proteins in the endoplasmic reticulum at the end of mitosis. Progerin displaced
the centromere protein F (CENP-F) from metaphase chromosome kinetochores, which
caused increased chromatin lagging, binucleated cells and genomic instability.
This accumulation of progerin-dependent defects with each round of mitosis
predisposes cells to premature senescence. Lamins are important constituents of the nuclear inner membrane and provide a
platform for transcription factors and chromatin. Progerin, a C-terminal
truncated lamin A mutant, causes premature aging termed Hutchinson-Gilford
Progeria Syndrome (HGPS). Oxidative stress appears to be involved in the
pathogenesis of HGPS, although the mechanistic role of progerin remains elusive.
Here we examined whether nuclear lamins are important for a cellular antioxidant
mechanism, and whether progerin compromises it. We investigated the activation
of nuclear factor-E2-related factor 2 (Nrf2) which regulates various antioxidant
genes including heme oxygenase-1 (HMOX1), following exposure to sodium arsenite
or cadmium chloride in lamin knockdown human cell lines and primary HGPS human
fibroblasts. Knocking down lamin A/C, or B, or all nuclear lamins simultaneously
in three human cell lines (HaCaT, SW480, and K562) did not impair arsenite- or
cadmium-induced activation of Nrf2. Progerin-expressing human primary HGPS
fibroblasts showed lower basal levels of HMOX1 and NQO1 expression; however, in
response to arsenic stress both normal and HGPS primary fibroblasts showed Nrf2
nuclear accumulation along with upregulation and phosphorylation of p62/SQSTM1
at Ser351, downregulation of Keap1, and comparable expression of an array of
downstream Nrf2-regulated antioxidant genes. We also observed new forms of
cleaved lamin A, B1 and B2 induced by cadmium stress although their roles in the
Nrf2 antioxidant system need further investigation. These results suggest that
the nuclear lamins and progerin have marginal roles in the activation of the
antioxidant Nrf2 response to arsenic and cadmium. BACKGROUND: Mutations in the LMNA gene are a common cause (6-8%) of dilated
cardiomyopathy (DCM) leading to heart failure, a growing health care problem
worldwide. The premature aging disease Hutchinson-Gilford syndrome (HGPS) is
also caused by defined mutations in the LMNA gene resulting in activation of a
cryptic splice donor site leading to a defective truncated prelamin A protein
called progerin. Low levels of progerin are expressed in healthy individuals
associated with ageing. Here, we aimed to address the role of progerin in
dilated cardiomyopathy.
METHODS AND RESULTS: mRNA expression of progerin was analyzed in heart tissue of
DCM (n = 15) and non-failing hearts (n = 10) as control and in blood samples
from patients with DCM (n = 56) and healthy controls (n = 10). Sequencing
confirmed the expression of progerin mRNA in the human heart. Progerin mRNA
levels derived from DCM hearts were significantly upregulated compared to
controls (1.27 ± 0.42 vs. 0.81 ± 0.24; p = 0.005). In contrast, progerin mRNA
levels in whole blood cells were not significantly different in DCM patients
compared to controls. Linear regression analyses revealed that progerin mRNA in
the heart is significantly negatively correlated to ejection fraction (r =
-0.567, p = 0.003) and positively correlated to left ventricular enddiastolic
diameter (r = 0.551, p = 0.004) but not with age of the heart per se. Progerin
mRNA levels were not influenced by inflammation in DCM hearts.
Immunohistochemistry and Immunofluorescence analysis confirmed increased
expression of progerin protein in cell nuclei of DCM hearts associated with
increased TUNEL+ apoptotic cells.
CONCLUSION: Our data suggest that progerin is upregulated in human DCM hearts
and strongly correlates with left ventricular remodeling. Progerin might be
involved in progression of heart failure and myocardial aging. Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disorder
characterized by accelerated cardiovascular disease with extensive fibrosis. It
is caused by a mutation in LMNA leading to expression of truncated prelamin A
(progerin) in the nucleus. To investigate the contribution of the endothelium to
cardiovascular HGPS pathology, we generated an endothelium-specific HGPS mouse
model with selective endothelial progerin expression. Transgenic mice develop
interstitial myocardial and perivascular fibrosis and left ventricular
hypertrophy associated with diastolic dysfunction and premature death.
Endothelial cells show impaired shear stress response and reduced levels of
endothelial nitric oxide synthase (eNOS) and NO. On the molecular level,
progerin impairs nucleocytoskeletal coupling in endothelial cells through
changes in mechanoresponsive components at the nuclear envelope, increased
F-actin/G-actin ratios, and deregulation of mechanoresponsive myocardin-related
transcription factor-A (MRTFA). MRTFA binds to the Nos3 promoter and reduces
eNOS expression, thereby mediating a profibrotic paracrine response in
fibroblasts. MRTFA inhibition rescues eNOS levels and ameliorates the
profibrotic effect of endothelial cells in vitro. Although this murine model
lacks the key anatomical feature of vascular smooth muscle cell loss seen in
HGPS patients, our data show that progerin-induced impairment of
mechanosignaling in endothelial cells contributes to excessive fibrosis and
cardiovascular disease in HGPS patients. In the last decade, we have seen increasing evidence of the importance of
structural nuclear proteins such as lamins in nuclear architecture and
compartmentalization of genome function and in the maintece of mechanical
stability and genome integrity. With over 400 mutations identified in the LMNA
gene (encoding for A-type lamins) associated with more than ten distinct
degenerative disorders, the role of lamins as genome caretakers and the
contribution of lamins dysfunction to disease are unarguable. However, the
molecular mechanisms whereby lamins mutations cause pathologies remain less
understood. Here, we review pathways and mechanisms recently identified as
playing a role in the pathophysiology of laminopathies, with special emphasis in
Hutchinson Gilford Progeria Syndrome (HGPS). This devastating incurable
accelerated aging disease is caused by a silent mutation in the LMNA gene that
generates a truncated lamin A protein "progerin" that exerts profound cellular
toxicity and organismal decline. Patients usually die in their teens due to
cardiovascular complications such as myocardial infarction or stroke. To date,
there are no efficient therapies that ameliorate disease progression, stressing
the need to understand molecularly disease mechanisms that can be targeted
therapeutically. We will summarize data supporting that replication stress is a
major cause of genomic instability in laminopathies, which contributes to the
activation of innate immune responses to self-DNA that in turn accelerate the
aging process. Hutchinson-Gilford progeria syndrome (HGPS), commonly called progeria, is an
extremely rare disorder that affects only one child per four million births. It
is characterized by accelerated aging in affected individuals leading to
premature death at an average age of 14.5 years due to cardiovascular
complications. The main cause of HGPS is a sporadic autosomal domit point
mutation in LMNA gene resulting in differently spliced lamin A protein known as
progerin. Accumulation of progerin under nuclear lamina and activation of its
downstream effectors cause perturbation in cellular morphology and physiology
which leads to a systemic disorder that mainly impairs the cardiovascular
system, bones, skin, and overall growth. Till now, no cure has been found for
this catastrophic disorder; however, several therapeutic strategies are under
development. The current review focuses on the overall progress in the field of
therapeutic approaches for the management/cure of HGPS. We have also discussed
the new disease models that have been developed for the study of this rare
disorder. Moreover, we have highlighted the therapeutic application of
extracellular vesicles derived from stem cells against aging and aging-related
disorders and, therefore, suggest the same for the treatment of HGPS. Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder
notably characterized by precocious and deadly atherosclerosis. Almost 90% of
HGPS patients carry a LMNA p.G608G splice variant that leads to the expression
of a permanently farnesylated abnormal form of prelamin-A, referred to as
progerin. Endothelial dysfunction is a key determit of atherosclerosis,
notably during aging. Previous studies have shown that progerin accumulates in
HGPS patients' endothelial cells but also during vascular physiological aging.
However, whether progerin expression in human endothelial cells can recapitulate
features of endothelial dysfunction is currently unknown. Herein, we evaluated
the direct impact of exogenously expressed progerin and wild-type lamin-A on
human endothelial cell function and senescence. Our data demonstrate that
progerin, but not wild-type lamin-A, overexpression induces endothelial cell
dysfunction, characterized by increased inflammation and oxidative stress
together with persistent DNA damage, increased cell cycle arrest protein
expression and cellular senescence. Inhibition of progerin prenylation using a
pravastatin-zoledronate combination partly prevents these defects. Our data
suggest a direct proatherogenic role of progerin in human endothelial cells,
which could contribute to HGPS-associated early atherosclerosis and also
potentially be involved in physiological endothelial aging participating to
age-related cardiometabolic diseases. BACKGROUND: Hutchinson-Gilford progeria syndrome (HGPS) is a progeroid disease
characterized by the early onset of age-related phenotypes including arthritis,
loss of body fat and hair, and atherosclerosis. Cells from affected individuals
express a mutant version of the nuclear envelope protein lamin A (termed
progerin) and have previously been shown to exhibit prominent histone
modification changes.
METHODS: Here, we analyze the possibility that epigenetic deregulation of
lamina-associated domains (LADs) is involved in the molecular pathology of HGPS.
To do so, we studied chromatin accessibility (Assay for Transposase-accessible
Chromatin (ATAC)-see/-seq), DNA methylation profiles (Infinium MethylationEPIC
BeadChips), and transcriptomes (RNA-seq) of nine primary HGPS fibroblast cell
lines and six additional controls, two parental and four age-matched healthy
fibroblast cell lines.
RESULTS: Our ATAC-see/-seq data demonstrate that primary dermal fibroblasts from
HGPS patients exhibit chromatin accessibility changes that are enriched in LADs.
Infinium MethylationEPIC BeadChip profiling further reveals that DNA methylation
alterations observed in HGPS fibroblasts are similarly enriched in LADs and
different from those occurring during healthy aging and Werner syndrome (WS),
another premature aging disease. Moreover, HGPS patients can be stratified into
two different subgroups according to their DNA methylation profiles. Finally, we
show that the epigenetic deregulation of LADs is associated with HGPS-specific
gene expression changes.
CONCLUSIONS: Taken together, our results strongly implicate epigenetic
deregulation of LADs as an important and previously unrecognized feature of
HGPS, which contributes to disease-specific gene expression. Therefore, they not
only add a new layer to the study of epigenetic changes in the progeroid
syndrome, but also advance our understanding of the disease's pathology at the
cellular level. |
What are the effects of ibrutinib on CART cell production? | CART cell generation in the presence of ibrutinib resulted in increased cell viability and expansion of CLL patient-derived CART cells. Furthermore, ibrutinib enriched CART cells with less-differentiated naïve-like phenotype and decreased expression of exhaustion markers including PD-1, TIM-3 and LAG-3. In addition, ibrutinib increased the cytokine release capacity of CLL patient-derived CART cells. In summary, BTK/ITK inhibition with ibrutinib during CART cell culture can improve yield and function of CLL patient-derived CART cell products. | Despite considerable advances in the treatment of multiple myeloma (MM) in the
last decade, a substantial proportion of patients do not respond to current
therapies or have a short duration of response. Furthermore, these treatments
can have notable morbidity and are not uniformly tolerated in all patients. As
there is no cure for MM, patients eventually become resistant to therapies,
leading to development of relapsed/refractory MM. Therefore, an unmet need
exists for MM treatments with novel mechanisms of action that can provide
durable responses, evade resistance to prior therapies, and/or are better
tolerated. B-cell maturation antigen (BCMA) is preferentially expressed by
mature B lymphocytes, and its overexpression and activation are associated with
MM in preclinical models and humans, supporting its potential utility as a
therapeutic target for MM. Moreover, the use of BCMA as a biomarker for MM is
supported by its prognostic value, correlation with clinical status, and its
ability to be used in traditionally difficult-to-monitor patient populations.
Here, we review three common treatment modalities used to target BCMA in the
treatment of MM: bispecific antibody constructs, antibody-drug conjugates, and
chimeric antigen receptor (CAR)-modified T-cell therapy. We provide an overview
of preliminary clinical data from trials using these therapies, including the
BiTE® (bispecific T-cell engager) immuno-oncology therapy AMG 420, the
antibody-drug conjugate GSK2857916, and several CAR T-cell therapeutic agents
including bb2121, NIH CAR-BCMA, and LCAR-B38M. Notable antimyeloma activity and
high minimal residual disease negativity rates have been observed with several
of these treatments. These clinical data outline the potential for BCMA-targeted
therapies to improve the treatment landscape for MM. Importantly, clinical
results to date suggest that these therapies may hold promise for deep and
durable responses and support further investigation in earlier lines of
treatment, including newly diagnosed MM. Chimeric antigen receptor T (CART) cells targeting CD19 have shown promising
results in the treatment of chronic lymphocytic leukemia (CLL). However,
efficacy seems to be inferior compared to diffuse large B-cell lymphoma or acute
lymphoblastic leukemia. Impaired T-cell fitness of CLL patients may be involved
in treatment failure. Less-differentiated naïve-like T cells play an important
role in CART expansion and long-term persistence in vivo. These cells are sparse
in CLL patients. Therefore, optimization of CART cell production protocols
enriching less differentiated T cell subsets may overcome treatment resistance.
The B-cell receptor inhibitor ibrutinib targeting Bruton's tyrosine kinase (BTK)
is approved for the treatment of CLL. Besides BTK, ibrutinib additionally
inhibits interleukin-2-inducible T-cell kinase (ITK) which is involved in T-cell
differentiation. To evaluate the effect of ibrutinib on CART cell production,
peripheral blood mononuclear cells from nine healthy donors and eight CLL
patients were used to generate CART cells. T-cell expansion and phenotype,
expression of homing and exhaustion makers as well as functionality of CART
cells were evaluated. CART cell generation in the presence of ibrutinib resulted
in increased cell viability and expansion of CLL patient-derived CART cells.
Furthermore, ibrutinib enriched CART cells with less-differentiated naïve-like
phenotype and decreased expression of exhaustion markers including PD-1, TIM-3
and LAG-3. In addition, ibrutinib increased the cytokine release capacity of CLL
patient-derived CART cells. In summary, BTK/ITK inhibition with ibrutinib during
CART cell culture can improve yield and function of CLL patient-derived CART
cell products. |
What is the role of miR-193b in prostate cancer? | Overexpression of miR-193b led to the inhibition of the majority of the 41 genes in prostate cancer cell lines. | miRNAs have proven to be key regulators of gene expression and are
differentially expressed in various diseases, including cancer. Our aim was to
identify epigenetically dysregulated genes in prostate cancer. We performed
miRNA expression profiling after relieving epigenetic modifications in 6
prostate cancer cell lines and nonmaligt prostate epithelial cells.
Thirty-eight miRNAs showed increased expression in any prostate cancer cell line
after 5-aza-2'-deoxycytidine (5azadC) and trichostatin A (TSA) treatments. Six
of these also had decreased expression in clinical prostate cancer samples
compared to benign prostatic hyperplasia. Among these, miR-193b was methylated
in 22Rv1 cell line at a CpG island approximately 1 kb upstream of the miRNA
locus. Expressing miR-193b in 22Rv1 cells using pre-miR-193b oligonucleotides
caused a significant growth reduction (p < 0.001) resulting from a decrease of
cells in S-phase of the cell cycle (p < 0.01). In addition, the anchorage
independent growth was partially inhibited in transiently miR-193b-expressing
22Rv1 cells (p < 0.01). Altogether, our data suggest that miR-193b is an
epigenetically silenced putative tumor suppressor in prostate cancer. Epigenetic silencing of miRNA is a primary mechanism of aberrant miRNA
expression in cancer, and hypermethylation of miRNA promoters has been reported
to contribute to prostate cancer initiation and progression. Recent data have
shown that the miR-193b promoter is hypermethylated in prostate cancer compared
with normal tissue, but studies assessing its functional significance have not
been performed. We aimed to elucidate the function of miR-193b and identify its
critical targets in prostate cancer. We observed an inverse correlation between
miR-193b level and methylation of its promoter in The Cancer Genome Atlas (TCGA)
cohort. Overexpression of miR-193b in prostate cancer cell lines inhibited
invasion and induced apoptosis. We found that a majority of the top 150 genes
downregulated when miR-193b was overexpressed in liposarcoma are overexpressed
in metastatic prostate cancer and that 41 miR-193b target genes overlapped with
the 86 genes in the aggressive prostate cancer subtype 1 (PCS1) signature.
Overexpression of miR-193b led to the inhibition of the majority of the 41 genes
in prostate cancer cell lines. High expression of the 41 genes was correlated
with recurrence of prostate cancer. Knockdown of miR-193b targets FOXM1 and RRM2
in prostate cancer cells phenocopied overexpression of miR-193b. Dual treatment
with DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibitors
decreased miR-193b promoter methylation and restored inhibition of FOXM1 and
RRM2. Our data suggest that silencing of miR-193b through promoter methylation
may release the inhibition of PCS1 genes, contributing to prostate cancer
progression and suggesting a possible therapeutic strategy for aggressive
prostate cancer. |
What treatment was studied in the KEYNOTE-522 trial? | KEYNOTE-522 trial studied adjuvant pembrolizumab for patients with triple-negative breast cancer. | Conflict of interest statement: Declaration of Interests P.S. has served as an
uncompensated consultant to Roche-Genentech. S.L. receives research funding to
her institution from Novartis, Bristol Meyers Squibb, Merck, Roche-Genentech,
Puma Biotechnology, Pfizer, Eli Lilly, and Seattle Genetics. She has acted as
consultant (not compensated) to Seattle Genetics, Pfizer, Novartis, BMS, Merck,
AstraZeneca, and Roche-Genentech. She has acted as consultant (paid to her
institution) to Aduro Biotech, Novartis, and G1 Therapeutics. PURPOSE: In both the IMpassion 130 trial in the metastatic setting and in
Keynote 522 in the neoadjuvant setting, patients with triple-negative breast
cancer (TNBC) showed benefit from PD-1 axis immunotherapy. Here, we assess PD-L1
expression on both tumor and immune cells using quantitative immunofluorescence
to assess association with benefit from neoadjuvant durvalumab concurrent with
chemotherapy in TNBC.
EXPERIMENTAL DESIGN: Pretreatment core needle biopsies (n = 69) were obtained
from patients who participated in a phase I/II clinical trial (NCT02489448). The
final analysis included 45 patients [pathologic complete response (pCR) = 18,
non-pCR = 27] due to technical issues and insufficient tissue. Slides were
stained using a previously validated Ultivue DNA-based Ultimapper kit (CD8,
CD68, PD-L1, Cytokeratin/Sox10, and Hoechst counterstain). The PD-L1 expression
was analyzed by molecular compartmentalization without segmentation using AQUA
software (version 3.2.2.1) in three tissue compartments including tumor
(cytokeratin-positive cells), CD68+ cells, and overall stroma.
RESULTS: In patients with pCR, PD-L1 expression was significantly higher in
tumor cells, in CD68+ cells and in the stroma compared with patients non-pCR.
There was no difference in the amount of CD68+ cells in the tumor or stromal
compartments between cases with pCR and non-pCR.
CONCLUSIONS: Expression of PD-L1 in tumor cells, immune cells in stroma, and
colocalized with CD68+ cells is associated with higher rates of pCR to
durvalumab and chemotherapy in TNBC. |
Which disease is associated with DNAJB1-PRKACA fusion gene? | Fibrolamellar carcinoma is distinctive at clinical and histologic levels. A novel DNAJB1-PRKACA fusion gene characterizes almost all cases. | Fibrolamellar carcinoma (FLC) is a rare variant of hepatocellular carcinoma,
occurring in children and young adults without underlying liver disease. The
diagnosis is based on morphological characteristics of the tumor, supplemented
by immunohistochemistry and/or genetic testing. Recently, the presence of a
characteristic DNAJB1-PRKACA fusion gene has been associated with FLC. Herein,
we report a case of FLC presenting as peritoneal carcinomatosis in a 14-year-old
female. Interestingly, no liver tumor was seen on imaging, and an alternative
possibility is that the tumor arose outside the liver as a hepatoid carcinoma
with fibrolamellar features. LESSONS LEARNED: The fibrolamellar carcinoma-associated DNAJB1-PRKACA gene
fusion transcript RNA codes for the catalytic domain of protein kinase A and,
thus, overexpression of Aurora kinase A. ENMD-2076 showed a favorable toxicity
profile. The limited results, one patient (3%) with a partial response and 57%
of patients with stable disease, do not support further evaluation of ENMD-2076
as single agent. Future studies will depend on the simultaneous targeting
approach of DNAJB1-PRKACA and the critical downstream components.
BACKGROUND: Fibrolamellar carcinoma (FLC) represents approximately 0.85% of
liver cancers. The associated DNAJB1-PRKACA gene fusion transcript RNA codes for
the catalytic domain of protein kinase A and overexpression of Aurora kinase A
(AURKA). ENMD-2076 is a selective anti-AURKA inhibitor.
METHODS: Patients aged >12 years with pathologically confirmed incurable FLC,
with measurable disease, Eastern Cooperative Oncology Group performance status
0-2 or Lansky 70-100, and adequate organ function were eligible. Patients were
prescribed ENMD-2076 based on body surface area. The primary endpoint was
overall objective response rate by RECIST v1.1, with a null hypothesis of true
response rate of 2% versus one-sided alternative of 15%. Secondary endpoints
included 6-month progression-free survival (PFS) rate (Fig. 1), median PFS, time
to progression (TTP), and overall survival (OS). Safety was evaluated throughout
the study.
RESULTS: Of 35 patients who enrolled and received treatment, 1 (3%) had a
partial response (PR) and 20 (57%) had stable disease (SD). Median TTP, PFS, and
OS were 5, 3.9, and 19 months, respectively. The most frequently reported
drug-related serious adverse event was hypertension in three patients. Three
deaths were reported on-study-two due to disease progression and one due to
pulmonary embolism not related to ENMD-2076.
CONCLUSION: The study provided no rationale for further studying ENMD-2076 as a
single agent in FLC. |
What is NTI, Nerve Tissue Contrast Index | The Nerve Tissue Index NTI is a ratio of average brightness levels of surrounding tissue and the median nerve, both calculated on the basis of a ultrasound image. | OBJECTIVES: To assess the feasibility of using ultrasound (US) image features
related to the median nerve echogenicity and shape for carpal tunnel syndrome
(CTS) diagnosis.
METHODS: In 31 participants (21 healthy participants and 10 patients with CTS),
US images were collected with a 30-MHz transducer from median nerves at the
wrist crease in 2 configurations: a neutral position and with wrist extension.
Various morphologic features, including the cross-sectional area (CSA), were
calculated to assess the nerve shape. Carpal tunnel syndrome commonly results in
loss of visualization of the nerve fascicular pattern on US images. To assess
this phenomenon, we developed a nerve-tissue contrast index (NTI) method. The
NTI is a ratio of average brightness levels of surrounding tissue and the median
nerve, both calculated on the basis of a US image. The area under the curve
(AUC) from a receiver operating characteristic curve analysis and t test were
used to assess the usefulness of the features for differentiation of patients
with CTS from control participants.
RESULTS: We obtained significant differences in the CSA and NTI parameters
between the patients with CTS and control participants (P < .01), with the
corresponding highest AUC values equal to 0.885 and 0.938, respectively. For the
remaining investigated morphologic features, the AUC values were less than
0.685, and the differences in means between the patients and control
participants were not statistically significant (P > .10). The wrist
configuration had no impact on differences in average parameter values
(P > .09).
CONCLUSIONS: Patients with CTS can be differentiated from healthy individuals on
the basis of the median nerve CSA and echogenicity. Carpal tunnel syndrome is
not manifested in a change of the median nerve shape that could be related to
circularity or contour variability. |
When was dupilumab approved by EMA? | Dupilumab was approved fby the EMA in 2017. | Atopic Dermatitis (AD) is a chronic inflammatory disease persisting
predomitly in the pediatric population. Treatment is generally supervised by
various medical specialists, including primary care practitioners, allergists,
and dermatologists. This divergence in disease management allows various
therapeutic approaches to be administered to patients by supervised physicians.
This article covers etiology of the disease and summarizes dermatologic
treatment standards of selected countries binding prior to the registration of
dupilumab by both the European Medicines Agency (EMA) and Federal Drug
Administration (FDA) in 2017. Before recent development in targeted therapies
(small molecules and biologic agents), standards in AD treatment remained
unchanged for years with extensive similarities across a sample group of
countries in particular geographic and economic regions. The spectrum of
available and popular therapeutic options can be categorized into three
dominating groups: non-pharmacologic, pharmacologic, and systemic interventions.
Their prescription, in principle, was historically driven by disease severity
and previous treatment history. However, advances in targeted therapies may
change AD management guidelines and medical care standards. |
Describe bigPint | BigPint is a data visualization package available on Bioconductor under the GPL-3 license (https://bioconductor.org/packages/release/bioc/html/bigPint.html). This software introduces new visualization technology that enables independent layers of interactivity using Plotly in R, which aids in the exploration of large biological datasets. The bigPint package presents modernized versions of scatterplot matrices, volcano plots, and litre plots through the implementation of layered interactivity. These graphics have detected normalization issues, differential expression designation problems, and common analysis errors in public RNA-sequencing datasets. Researchers can apply bigPint graphics to their data by following recommended pipelines written in reproducible code in the user manual. | Interactive data visualization is imperative in the biological sciences. The
development of independent layers of interactivity has been in pursuit in the
visualization community. We developed bigPint, a data visualization package
available on Bioconductor under the GPL-3 license
(https://bioconductor.org/packages/release/bioc/html/bigPint.html). Our software
introduces new visualization technology that enables independent layers of
interactivity using Plotly in R, which aids in the exploration of large
biological datasets. The bigPint package presents modernized versions of
scatterplot matrices, volcano plots, and litre plots through the implementation
of layered interactivity. These graphics have detected normalization issues,
differential expression designation problems, and common analysis errors in
public RNA-sequencing datasets. Researchers can apply bigPint graphics to their
data by following recommended pipelines written in reproducible code in the user
manual. In this paper, we explain how we achieved the independent layers of
interactivity that are behind bigPint graphics. Pseudocode and source code are
provided. Computational scientists can leverage our open-source code to expand
upon our layered interactive technology and/or apply it in new ways toward other
computational biology tasks. |
Aducanumab can be used for treatment of which disease? | Aducanumab is approved for treatment of Alzheimer's disease. | Alzheimer's disease (AD) is characterized by deposition of amyloid-β (Aβ)
plaques and neurofibrillary tangles in the brain, accompanied by synaptic
dysfunction and neurodegeneration. Antibody-based immunotherapy against Aβ to
trigger its clearance or mitigate its neurotoxicity has so far been
unsuccessful. Here we report the generation of aducanumab, a human monoclonal
antibody that selectively targets aggregated Aβ. In a transgenic mouse model of
AD, aducanumab is shown to enter the brain, bind parenchymal Aβ, and reduce
soluble and insoluble Aβ in a dose-dependent manner. In patients with prodromal
or mild AD, one year of monthly intravenous infusions of aducanumab reduces
brain Aβ in a dose- and time-dependent manner. This is accompanied by a slowing
of clinical decline measured by Clinical Dementia Rating-Sum of Boxes and Mini
Mental State Examination scores. The main safety and tolerability findings are
amyloid-related imaging abnormalities. These results justify further development
of aducanumab for the treatment of AD. Should the slowing of clinical decline be
confirmed in ongoing phase 3 clinical trials, it would provide compelling
support for the amyloid hypothesis. The amyloid hypothesis has been the domit framework for Alzheimer's disease
(AD) research, including the development of anti-AD therapies. However, none of
the phase III clinical trials conducted to date that targeted amyloid β (Aβ)
production, aggregation, or clearance demonstrated a statistically significant
treatment effect in patients with AD. This includes the approach of using
monoclonal antibodies that recognize various Aβ epitopes and display different
binding selectivity. While some monoclonal antibodies have failed in phase III
trials, several are still in development. Aducanumab (BIIB037) is a human
antibody that selectively targets aggregated forms of Aβ, including soluble
oligomers and insoluble fibrils. In PRIME (NCT01677572), an ongoing phase Ib
trial (N=196 patients dosed), aducanumab was shown to reduce Aβ plaques and slow
decline in clinical measures in patients with prodromal or mild AD, with
acceptable safety and tolerability. The main safety finding was amyloid-related
imaging abnormalities (ARIA), a side effect associated with removal of Aβ, which
was dose-dependent and occurred more often in ApoE ε4 carriers than
non-carriers. ENGAGE (NCT02477800) and EMERGE (NCT02484547), the ongoing phase
III trials of aducanumab in early AD, have been designed based on the outcomes
of PRIME and on lessons from past clinical trials in patients with AD. Those
study design features include patient selection with confirmed Aβ pathology,
ensuring sufficient target engagement, and conducting clinical trials in
patients at earlier symptomatic stages of AD. Aducanumab, a human-derived antibody targeting amyloid-β (Aβ), is in Phase 3
clinical trials for the treatment of Alzheimer's disease. Biochemical and
structural analyses show that aducanumab binds a linear epitope formed by amino
acids 3-7 of the Aβ peptide. Aducanumab discriminates between monomers and
oligomeric or fibrillar aggregates based on weak monovalent affinity, fast
binding kinetics and strong avidity for epitope-rich aggregates. Direct
comparative studies with analogs of gantenerumab, bapineuzumab and solanezumab
demonstrate clear differentiation in the binding properties of these antibodies.
The crystal structure of the Fab fragment of aducanumab bound to its epitope
peptide reveals that aducanumab binds to the N terminus of Aβ in an extended
conformation, distinct from those seen in structures with other antibodies that
target this immunodomit epitope. Aducanumab recognizes a compact epitope that
sits in a shallow pocket on the antibody surface. In silico analyses suggest
that aducanumab interacts weakly with the Aβ monomer and may accommodate a
variety of peptide conformations, further supporting its selectivity for Aβ
aggregates. Our studies provide a structural rationale for the low affinity of
aducanumab for non-pathogenic monomers and its greater selectivity for
aggregated forms than is seen for other Aβ-targeting antibodies. BACKGROUND: Aducanumab is an anti-amyloid-β (Aβ) antibody that achieved reduced
amyloid pathology in Alzheimer's disease (AD) trials; however, it is
controversial whether it also improved cognition, which has been suggested would
require a sufficiently high cumulative dose of the antibody in the brain.
Therapeutic ultrasound, in contrast, has only begun to be investigated in human
AD clinical trials. We have previously shown that scanning ultrasound in
combination with intravenously injected microbubbles (SUS), which temporarily
and safely opens the blood-brain barrier (BBB), removes amyloid and restores
cognition in APP23 mice. However, there has been no direct testing of how the
effects of SUS compare to immunotherapy or whether a combination therapy is more
effective.
METHODS: In a study comprising four treatment arms, we tested the efficacy of an
Aducanumab analog, Adu, both in comparison to SUS, and as a combination therapy,
in APP23 mice (aged 13-22 months), using sham as a control. The active place
avoidance (APA) test was used to test spatial memory, and histology and ELISA
were used to measure amyloid. Brain antibody levels were also determined.
RESULTS: We found that both Adu and SUS reduced the total plaque area in the
hippocampus with no additive effect observed with the combination treatment
(SUS + Adu). Whereas in the cortex where there was a trend towards reducing the
total plaque area from either Adu or SUS, only the combination treatment yielded
a statistically significant decrease in total plaque area compared to sham. Only
the SUS and SUS + Adu groups included animals that had their plaque load reduced
to below 1% from above 10%. There was a robust improvement in spatial memory for
the SUS + Adu group only, and in this group the level of Adu, when measured
3 days post-treatment, was 5-fold higher compared to those mice that received
Adu on its own. Together, these findings suggest that SUS should be considered
as a treatment option for AD. Alternatively, a combination trial using
Aducanumab together with ultrasound to increase brain levels of the antibody may
be warranted. Alzheimer's disease (AD) is an irreversible brain disorder associated with
severe progressive dementia and is characterized by deposits of amyloid plaques
in the brain. Over the past 20 years, the mortality of strokes and heart disease
has decreased, but deaths from AD have increased. The four drugs used clinically
to treat AD can only relieve symptoms but cannot slow the progression of the
disease. Aducanumab, a human monoclonal antibody that preferentially binds to
aggregated amyloid-β to reduce the number of amyloid plaques and slow disease
progression, was approved to treat AD by the US Food and Drug Administration on
June 7, 2021. It is the first disease-modifying therapy for AD, but there is
considerable controversy regarding the drug's approval. Aducanumab offers hope
for millions of patients. On June 7, 2021, the US Food and Drug Administration (FDA) approved aducanumab,
a monoclonal amyloid targeting β-amyloid, for the treatment for Alzheimer's
disease (AD). This decision was achieved through the Accelerated Approval
Pathway and was essentially motivated by the evidence that aducanumab reduces
brain amyloid plaques. This news is causing a heated debate in the scientific
community. On the one hand, aducanumab is the first drug to be approved for the
treatment of the disease since 2003 and is the first drug to act on the alleged
pathophysiological mechanisms of AD. At the same time, the evidence of clinical
benefit coming from two phase 3 clinical trials is contradictory and still
inconclusive. The aim of the present editorial is to provide some points to
consider that can help understand the peculiarities and implications of this
approval and feed the scientific debate underway. Alzheimer's disease (AD) is the most common form of dementia with global burden
projected to triple by 2050. It incurs significant biopsychosocial burden
worldwide with limited treatment options. Aducanumab is the first monoclonal
antibody recently approved by the US-FDA for mild AD through the accelerated
approval pathway. It is the first molecule to be approved for AD since 2003 and
carries with it a therapeutic promise for the future. As the definition of AD
has evolved from a pathological entity to a Clinico-biological construct over
the years, the amyloid-β (Aβ) pathway has been increasingly implicated in its
pathogenesis. The approval of Aducanumab is based on reduction of the Aβ load in
the brain, which forms a surrogate marker for this pathway. The research
populace has, however, been globally divided by skepticism and hope regarding
this approval. Failure to meet clinical endpoints in the trials, alleged
transparency issues, cost-effectiveness, potential adverse effects, need for
regular monitoring, and critique of 'amyloid cascade hypothesis' itself are the
main caveats concerning the antibody. With this controversy in background, this
paper critically looks at antibody research in AD therapeutics, evidence, and
evolution of Aducanumab as a drug and the potential clinical implications of its
use in future. While the efficacy of this monoclonal antibody in AD stands as a
test of time, based on the growing evidence it is vital to rethink and explore
alternate pathways of pathogenesis (oxidative stress, neuroinflammation,
cholesterol metabolism, vascular factors, etc.) as possible therapeutic targets
that may help elucidate the enigma of this complex yet progressive and
debilitating neurodegenerative disorder. The amyloid-β (Aβ) oligomer hypothesis of Alzheimer's disease (AD) still
dominates the field, yet the clinical trial evidence does not robustly support
it. A falsifiable prediction of the hypothesis is that Aβ oligomer levels should
be elevated in the brain regions and at the disease stages where and when neuron
death and synaptic protein loss begin and are the most severe, but we review
previous evidence to demonstrate that this is not consistently the case. To
rescue the Aβ oligomer hypothesis from falsification, we propose the novel
ad-hoc hypothesis that the exceptionally vulnerable hippocampus may normally
produce Aβ peptides even in healthily aging individuals, and hippocampal
oxidatively damaged DNA, pathogen DNA, and metal ions such as zinc may initiate
and drive Aβ peptide aggregation into oligomers and spreading, neuron death,
synaptic dysfunction, and other aspects of AD neurodegeneration. We highlight
additional evidence consistent with the underwhelming efficacy of Aβ
oligomer-lowering agents, such as aducanumab, and of antioxidants, such as
vitamin E, versus the so far isolated case report that DNase-I treatment for 2
months resulted in a severe AD patient's Mini-Mental State Exam score increasing
from 3 to 18, reversing his diagnosis to moderate AD, according to the
Mini-Mental State Exam. On 7 June 2021, aducanumab was granted accelerated approval for the treatment of
Alzheimer disease (AD) by the FDA on the basis of amyloid-lowering effects
considered reasonably likely to confer clinical benefit. This decision makes
aducanumab the first new drug to be approved for the treatment of AD since 2003
and the first drug to ever be approved for modification of the course of AD.
Many have questioned how scientific evidence, expert advice and the best
interests of patients and families were considered in the approval decision. In
this article, we argue that prior to approval, the FDA and Biogen's shared
interpretation of clinical trial data - that high-dose aducanumab was
substantially clinically effective - avoided conventional scientific scrutiny,
was prominently advanced by patient representative groups who had been major
recipients of Biogen funds, and raised concerns that safeguards were
insufficient to mitigate regulatory capture within the FDA. Here, we reflect on
events leading to the FDA's decision on 7 June 2021 and consider whether any
lessons can be learned for the field. Alzheimer's disease and Lewy body diseases are the most common causes of
neurodegeneration and dementia. Amyloid-beta (Aβ) and alpha-synuclein (αSyn) are
two key proteins involved in the pathogenesis of these neurodegenerative
diseases. Immunotherapy aims to reduce the harmful effects of protein
accumulation by neutralising toxic species and facilitating their removal. The
results of the first immunisation trial against Aβ led to a small percentage of
meningoencephalitis cases which revolutionised vaccine design, causing a shift
in the field of immunotherapy from active to passive immunisation. While the
vast majority of immunotherapies have been developed for Aβ and tested in
Alzheimer's disease, the field has progressed to targeting other proteins
including αSyn. Despite showing some remarkable results in animal models,
immunotherapies have largely failed final stages of clinical trials to date,
with the exception of Aducanumab recently licenced in the US by the FDA.
Neuropathological findings translate quite effectively from animal models to
human trials, however, cognitive and functional outcome measures do not. The
apparent lack of translation of experimental studies to clinical trials suggests
that we are not obtaining a full representation of the effects of
immunotherapies from animal studies. Here we provide a background understanding
to the key concepts and challenges involved in therapeutic design. This review
further provides a comprehensive comparison between experimental and clinical
studies in Aβ and αSyn immunotherapy and aims to determine the possible reasons
for the disconnection in their outcomes. The recent approval of aducanumab for Alzheimer's disease has heightened the
interest in therapies targeting the amyloid hypothesis. Our research has focused
on identification of novel compounds to improve amyloid processing by modulating
gamma secretase activity, thereby addressing a significant biological deficit
known to plague the familial form of the disease. Herein, we describe the
design, synthesis, and optimization of new gamma secretase modulators (GSMs)
based on previously reported oxadiazine 1. Potency improvements with a focus on
predicted and measured properties afforded high-quality compounds further
differentiated via robust Aβ42 reductions in both rodents and nonhuman primates.
Extensive preclinical profiling, efficacy studies, and safety studies resulted
in the nomination of FRM-024,
(+)-cis-5-(4-chlorophenyl)-6-cyclopropyl-3-(6-methoxy-5-(4-methyl-1H-imidazole-1-yl)pyridin-2-yl)-5,6-dihydro-4H-1,2,4-oxadiazine,
as a GSM preclinical candidate for familial Alzheimer's disease. The pipeline for new treatments for Alzheimer's disease (AD) in the USA contains
over 100 different agents, 80% of which can be categorized as disease-modifying
therapies. The regulatory approval of the disease-modifying agent aducanumab has
brought more attention to the complexity of the diagnosis, evaluation, and
treatment of AD and the difficult decisions payers and policy makers will face
over the next few years as innovation continues in this space. The value of AD
treatment can vary widely according to the perspective of the analysis, sources
of data, and methodological approach for the value assessment. This article
focuses on AD-specific data gaps and measurement challenges and provides
guidance for evidence generation to facilitate better value assessments for
future AD treatments. Aducanumab (Aduhelm), the first new drug to treat Alzheimer's disease since
2003, has received accelerated approval from the Food and Drug Administration
(FDA).This drug's approval has been highly contentious in the medical and
scientific community owing to contradictory study findings and the FDA's
advisory panel not recommending its approval. Conflict of interest statement: Disclosure and potential conflicts of interest:
RRT has none. BF reports grants and other from Biogen during the conduct of the
study and grants from Lilly, Eisai, NIH, Rogers Family Foundation and Spier
Family Foundation and other from Acadia Pharmaceuticals, outside the submitted
work. MA reports consulting for Biogen, Otsuka and Eli Lilly. The International
Committee of Medical Journal Editors (ICMJE) Potential Conflicts of Interests
form for the authors is available for download at:
https://www.drugsincontext.com/wp-content/uploads/2021/09/dic.2021-7-3-COI.pdf Based on the reduction of amyloid β plaques, US FDA has recently approved
Aducanumab as a disease modifying treatment for Alzheimer's disease (AD). With
high pricing and the potential risks likely with this treatment, certainty of AD
diagnosis becomes crucial. The current pilot study evaluated plasma levels of
neurofilament L, an axonal injury marker and amyloid β42, a major component of
amyloid plaques for discriminating AD from non-AD dementia (NAD). Results with
Simoa assays indicate that a combination of neurofilament L and amyloid β42 can
be considered as a screening tool in identifying eligible subjects for AD
treatment/ clinical trials. |
Can IFNg induce the expression of IDO? | Yes,
IFNG-induce up-regulation of indoleamine 2,3-dioxygenase (IDO) | C57BL/6 mice are known to be resistant to the development of collagen-induced
arthritis (CIA). However, they show a severe arthritic phenotype when the Ifng
gene is deleted. Although it has been proposed that IFN-γ suppresses
inflammation in CIA via suppressing Th17 which is involved in the pathogenesis
of CIA, the exact molecular mechanism of the Th17 regulation by IFN-γ is poorly
understood. This study was conducted to 1) clarify that arthritogenic condition
of IFN-γ knockout (KO) mice is dependent on the disinhibition of Th17 and 2)
demonstrate that IFN-γ-induced indoleamine-2,3-dioxgenase (IDO) is engaged in
the regulation of Th17. The results showed that the IFN-γ KO mice displayed
increased levels of IL-17 producing T cells and the exacerbation of arthritis.
Also, production of IL-17 by the splenocytes of the IFN-γ KO mice was increased
when cultured with type II collagen. When Il17 was deleted from the IFN-γ KO
mice, only mild arthritis developed without any progression of the arthritis
score. The proportion of CD44(high)CD62L(low) memory-like T cells were elevated
in the spleen, draining lymph node and mesenteric lymph node of IFN-γ KO CIA
mice. Meanwhile, CD44(low)CD62L(high) naïve T cells were increased in IFN-γ and
IL-17 double KO CIA mice. When Th17 polarized CD4+ T cells of IFN-γ KO mice were
co-cultured with their own antigen presenting cells (APCs), a greater increase
in IL-17 production was observed than in co-culture of the cells from wild type
mice. In contrast, when APCs from IFN-γ KO mice were pretreated with IFN-γ,
there was a significant reduction in IL-17 in the co-culture system. Of note,
pretreatment of 1-methyl-DL- tryptophan, a specific inhibitor of IDO, abolished
the inhibitory effects of IFN-γ. Given that IFN-γ is a potent inducer of IDO in
APCs, these results suggest that IDO is involved in the regulation of IL-17 by
IFN-γ. The indoleamine 2,3-dioxygenase (IDO) enzyme can act as an immunoregulator by
inhibiting T cell function via the degradation of the essential amino acid
tryptophan (trp) into kynurenine (kyn) and its derivates. The kyn/trp ratio in
serum is a prognostic factor for cervical cancer patients; however, information
about the relationship between serum levels and IDO expression in the tumor is
lacking. IDO expression was studied in 71 primary and 14 paired metastatic
cervical cancer samples by various immunohistochemical (IHC) techniques,
including 7-color fluorescent multiparameter IHC, and the link between the
concentration of IDO metabolites in serum, clinicopathological characteristics,
and the presence of (proliferating) T cells (CD8, Ki67, and FoxP3) was examined.
In addition, we compared the relationships between IDO1 and IFNG gene expression
and clinical parameters using RNAseq data from 144 cervical tumor samples
published by The Cancer Genome Atlas (TCGA). Here, we demonstrate that patchy
tumor IDO expression is associated with an increased systemic kyn/trp ratio in
cervical cancer (P = 0.009), whereas marginal tumor expression at the interface
with the stroma is linked to improved disease-free (DFS) (P = 0.017) and
disease-specific survival (P = 0.043). The latter may be related to T cell
infiltration and localized IFNγ release inducing IDO expression. Indeed, TCGA
analysis of 144 cervical tumor samples revealed a strong and positive
correlation between IDO1 and IFNG mRNA expression levels (P < 0.001) and a
significant association with improved DFS for high IDO1 and IFNG transcript
levels (P = 0.031). Unexpectedly, IDO+ tumors had higher CD8+Ki67+ T cell rates
(P = 0.004). Our data thus indicate that the serum kyn/trp ratio and IDO
expression in primary tumor samples are not clear-cut biomarkers for prognosis
and stratification of patients with early stage cervical cancer for clinical
trials implementing IDO inhibitors. Rather, a marginal IDO expression pattern in
the tumor domitly predicts favorable outcome, which might be related to IFNγ
release in the cervical tumor microenvironment. AIMS: Neutrophil granulocytes are the major cells involved in Chlamydia
trachomatis (C. trachomatis)-mediated inflammation and histopathology. A key
protein in human intracellular antichlamydial defense is the
tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO) which limits the
growth of the tryptophan auxotroph Chlamydia. Despite its importance, the role
of IDO in the intracellular defense against Chlamydia in neutrophils is not well
characterized.
METHODS: Global gene expression screen was used to evaluate the effect of C.
trachomatis serovar D infection on the transcriptome of human neutrophil
granulocytes. Tryptophan metabolite concentrations in the Chlamydia-infected
and/or interferon-gamma (IFNG)-treated neutrophils were measured by
ultra-high-performance liquid chromatography-tandem mass spectrometry
(UHPLC-MS/MS).
RESULTS: Our results indicate that the C. trachomatis infection had a major
impact on neutrophil gene expression, inducing 1,295 genes and repressing 1,510
genes. A bioinformatics analysis revealed that important factors involved in the
induction of neutrophil gene expression were the interferon-related
transcription factors such as IRF1-5, IRF7-9, STAT2, ICSB, and ISGF3. One of the
upregulated genes was ido1, a known infection- and interferon-induced host gene.
The tryptophan-degrading activity of IDO1 was not induced significantly by
Chlamydia infection alone, but the addition of IFNG greatly increased its
activity. Despite the significant IDO activity in IFNG-treated cells, C.
trachomatis growth was not affected by IFNG. This result was in contrast to what
we observed in HeLa human cervical epithelial cells, where the IFNG-mediated
inhibition of C. trachomatis growth was significant and the IFNG-induced IDO
activity correlated with growth inhibition.
CONCLUSIONS: IDO activity was not able to inhibit chlamydial growth in human
neutrophils. Whether the IDO activity was not high enough for inhibition or
other chlamydial growth-promoting host mechanisms were induced in the infected
and interferon-treated neutrophils needs to be further investigated. |
Covid-19 is though to have arisen from what species? | COVID-19 caused by SARS-CoV-2 most likely originated in bats and transmitted to humans through a possible intermediate host. | SUMMARYIn recent decades, several new diseases have emerged in different
geographical areas, with pathogens including Ebola virus, Zika virus, Nipah
virus, and coronaviruses (CoVs). Recently, a new type of viral infection emerged
in Wuhan City, China, and initial genomic sequencing data of this virus do not
match with previously sequenced CoVs, suggesting a novel CoV strain (2019-nCoV),
which has now been termed severe acute respiratory syndrome CoV-2 (SARS-CoV-2).
Although coronavirus disease 2019 (COVID-19) is suspected to originate from an
animal host (zoonotic origin) followed by human-to-human transmission, the
possibility of other routes should not be ruled out. Compared to diseases caused
by previously known human CoVs, COVID-19 shows less severe pathogenesis but
higher transmission competence, as is evident from the continuously increasing
number of confirmed cases globally. Compared to other emerging viruses, such as
Ebola virus, avian H7N9, SARS-CoV, and Middle East respiratory syndrome
coronavirus (MERS-CoV), SARS-CoV-2 has shown relatively low pathogenicity and
moderate transmissibility. Codon usage studies suggest that this novel virus has
been transferred from an animal source, such as bats. Early diagnosis by
real-time PCR and next-generation sequencing has facilitated the identification
of the pathogen at an early stage. Since no antiviral drug or vaccine exists to
treat or prevent SARS-CoV-2, potential therapeutic strategies that are currently
being evaluated predomitly stem from previous experience with treating
SARS-CoV, MERS-CoV, and other emerging viral diseases. In this review, we
address epidemiological, diagnostic, clinical, and therapeutic aspects,
including perspectives of vaccines and preventive measures that have already
been globally recommended to counter this pandemic virus. PURPOSE OF REVIEW: SARS-CoV-2, the recently emerged coronavirus (CoV) that is
responsible for the current global pandemic Covid-19, first appeared in late
2019 in Wuhan, China. Here, we summarise details of the SARS-CoV-2 genome to
assist understanding of the emergence, evolution and diagnosis of this deadly
new virus.
RECENT FINDINGS: Based on high similarities in the genome sequences, the virus
is thought to have arisen from SARS-like CoVs in bats but the lack of an
intermediate species containing a CoV with even greater similarity has so far
eluded discovery. The critical determit of the SARS-CoV-2 genome is the spike
(S) gene encoding the viral structural protein that interacts with the host cell
entry receptor ACE2. The S protein is sufficiently adapted to bind human ACE2
much more readily than SARS-CoV, the most closely related human CoV.
SUMMARY: Although the SARS-CoV-2 genome is undergoing subtle evolution in humans
through mutation that may enhance transmission, there is limited evidence for
attenuation that might weaken the virus. It is also still unclear as to the
events that led to the virus' emergence from bats. Importantly, current
diagnosis requires specific recognition and amplification of the SARS-CoV-2 RNA
genome by qPCR, despite these ongoing viral genome changes. Alternative
diagnostic procedures relying on immunoassay are becoming more prevalent. |
Are TAMs good anticancer therapeutic targets? | Therapeutic strategies to target TAMs to complement conventional therapies has yielded promising results. | |
Describe meCLICK-Seq | MeCLICK-Seq is a method to identify RNA modification substrates with high resolution at intronic and intergenic regions. The method hijacks RNA methyltransferase activity to introduce an alkyne, instead of a methyl, moiety on RNA. | The fates of RNA species in a cell are controlled by ribonucleases, which
degrade them by exploiting the universal structural 2'-OH group. This phenomenon
plays a key role in numerous transformative technologies, for example, RNA
interference and CRISPR/Cas13-based RNA editing systems. These approaches,
however, are genetic or oligomer-based and so have inherent limitations. This
has led to interest in the development of small molecules capable of degrading
nucleic acids in a targeted manner. Here we describe click-degraders, small
molecules that can be covalently attached to RNA species through click-chemistry
and can degrade them, that are akin to ribonucleases. By using these molecules,
we have developed the meCLICK-Seq (methylation CLICK-degradation Sequencing) a
method to identify RNA modification substrates with high resolution at intronic
and intergenic regions. The method hijacks RNA methyltransferase activity to
introduce an alkyne, instead of a methyl, moiety on RNA. Subsequent
copper(I)-catalyzed azide-alkyne cycloaddition reaction with the click-degrader
leads to RNA cleavage and degradation exploiting a mechanism used by endogenous
ribonucleases. Focusing on N6-methyladenosine (m6A), meCLICK-Seq identifies
methylated transcripts, determines RNA methylase specificity, and reliably maps
modification sites in intronic and intergenic regions. Importantly, we show that
METTL16 deposits m6A to intronic polyadenylation (IPA) sites, which suggests a
potential role for METTL16 in IPA and, in turn, splicing. Unlike other methods,
the readout of meCLICK-Seq is depletion, not enrichment, of modified RNA
species, which allows a comprehensive and dynamic study of RNA modifications
throughout the transcriptome, including regions of low abundance. The
click-degraders are highly modular and so may be exploited to study any RNA
modification and design new technologies that rely on RNA degradation. |
What is the mechanism of action of Lumasiran? | Lumasiran is a subcutaneously administered small interfering RNA targeting the mRNA for hydroxyacid oxidase 1 gene that is used for the treatment of primary hyperoxaluria type 1 (PH1). By silencing the gene encoding glycolate oxidase, lumasiran depletes glycolate oxidase and thereby inhibits the synthesis of oxalate, which is the toxic metabolite that is directly associated with the clinical manifestations of PH1. | Primary hyperoxalurias (PHs) are a group of inherited alterations of the hepatic
glyoxylate metabolism. PHs classification based on gene mutations parallel a
variety of enzymatic defects, and all involve the harmful accumulation of
calcium oxalate crystals that produce systemic damage. These geographically
widespread rare diseases have a deep impact in the life quality of the patients.
Until recently, treatments were limited to palliative measures and kidney/liver
transplants in the most severe forms. Efforts made to develop pharmacological
treatments succeeded with the biotechnological agent lumasiran, a siRNA product
against glycolate oxidase, which has become the first effective therapy to treat
PH1. However, small molecule drugs have classically been preferred since they
benefit from experience and have better pharmacological properties. The
development of small molecule inhibitors designed against key enzymes of
glyoxylate metabolism is on the focus of research. Enzyme inhibitors are
successful and widely used in several diseases and their pharmacokinetic
advantages are well known. In PHs, effective enzymatic targets have been
determined and characterized for drug design and interesting inhibitory
activities have been achieved both in vitro and in vivo. This review describes
the most recent advances towards the development of small molecule enzyme
inhibitors in the treatment of PHs, introducing the multi-target approach as a
more effective and safe therapeutic option. Primary hyperoxaluria type 1 is a rare genetic disease; the onset of symptoms
ranges from childhood to the sixth decade of life and the disease may go
unrecognized for several years. There is an urgent need for drugs able to
inhibit the liver production of oxalate and to prevent the disease progression;
lumasiran, an innovative molecule based on RNAi interference, is one of the most
promising drugs. A group of leading Italian experts on this disease met to
respond to some unmet medical needs (early diagnosis, availability of genetic
tests and dosage of plasma oxalate, timing of liver transplantation, need for
etiologic treatment), based on the analysis of the main scientific evidence and
their personal experience. Children showing the characteristic symptoms of the
disease usually undergo a metabolic screening and obtain an early diagnosis,
while the experience is very limited in adults and the diagnosis difficult. It
is therefore essential to increase the knowledge around this disease and the
importance of metabolic and genetic screening to define a checklist of shared
clinical and laboratory criteria and to establish a multidisciplinary management
of potential patients. Oxalate is the cause of the disease: it is crucial to
reduce both oxaluria and oxalemia through appropriate therapeutic strategies,
able to prevent and/or reduce renal and systemic complications of primary type 1
hyperoxaluria. Lumasiran allows to significantly reduce the levels of oxalate
both in blood and in urine, halting the course of the disease and preventing
serious renal and systemic complications, if the therapy is started at an early
stage of the disease. BACKGROUND AND OBJECTIVES: In the rare disease primary hyperoxaluria type 1,
overproduction of oxalate by the liver causes kidney stones, nephrocalcinosis,
kidney failure, and systemic oxalosis. Lumasiran, an RNA interference
therapeutic, suppresses glycolate oxidase, reducing hepatic oxalate production.
The objective of this first-in-human, randomized, placebo-controlled trial was
to evaluate the safety, pharmacokinetic, and pharmacodynamic profiles of
lumasiran in healthy participants and patients with primary hyperoxaluria type
1.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This phase 1/2 study was
conducted in two parts. In part A, healthy adults randomized 3:1 received a
single subcutaneous dose of lumasiran or placebo in ascending dose groups (0.3-6
mg/kg). In part B, patients with primary hyperoxaluria type 1 randomized 3:1
received up to three doses of lumasiran or placebo in cohorts of 1 or 3 mg/kg
monthly or 3 mg/kg quarterly. Patients initially assigned to placebo crossed
over to lumasiran on day 85. The primary outcome was incidence of adverse
events. Secondary outcomes included pharmacokinetic and pharmacodynamic
parameters, including measures of oxalate in patients with primary hyperoxaluria
type 1. Data were analyzed using descriptive statistics.
RESULTS: Thirty-two healthy participants and 20 adult and pediatric patients
with primary hyperoxaluria type 1 were enrolled. Lumasiran had an acceptable
safety profile, with no serious adverse events or study discontinuations
attributed to treatment. In part A, increases in mean plasma glycolate
concentration, a measure of target engagement, were observed in healthy
participants. In part B, patients with primary hyperoxaluria type 1 had a mean
maximal reduction from baseline of 75% across dosing cohorts in 24-hour urinary
oxalate excretion. All patients achieved urinary oxalate levels ≤1.5 times the
upper limit of normal.
CONCLUSIONS: Lumasiran had an acceptable safety profile and reduced urinary
oxalate excretion in all patients with primary hyperoxaluria type 1 to
near-normal levels.
CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Study of Lumasiran in
Healthy Adults and Patients with Primary Hyperoxaluria Type 1, NCT02706886. RNA interference (RNAi) is a natural biological pathway that inhibits gene
expression by targeted degradation or translational inhibition of cytoplasmic
mRNA by the RNA induced silencing complex. RNAi has long been exploited in
laboratory research to study the biological consequences of the reduced
expression of a gene of interest. More recently RNAi has been demonstrated as a
therapeutic avenue for rare metabolic diseases. This review presents an overview
of the cellular RNAi machinery as well as therapeutic RNAi design and delivery.
As a clinical example we present primary hyperoxaluria, an ultrarare inherited
disease of increased hepatic oxalate production which leads to recurrent calcium
oxalate kidney stones. In the most common form of the disease (Type 1),
end-stage kidney disease occurs in childhood or young adulthood, often
necessitating combined kidney and liver transplantation. In this context we
discuss nedosiran (Dicerna Pharmaceuticals, Inc.) and lumasiran (Alnylam
Pharmaceuticals), which are both novel RNAi therapies for primary hyperoxaluria
that selectively reduce hepatic expression of lactate dehydrogenase and
glycolate oxidase respectively, reducing hepatic oxalate production and urinary
oxalate levels. Finally, we consider future optimizations advances in RNAi
therapies. |
Where are Goblet cells localized? | Goblet cells are found in the intestine, in the lungs, in the eyes etc. Goblet cells are localized in the epithelium. | Conjunctival goblet cells (CGCs) are specialized cells that produce and secrete
soluble mucins to the tear film that bathes the ocular surface. CGC numbers and
functions are affected in various ocular surface diseases including dry eye
disease with diverse etiologies. In this review we will (i) summarize the
important functions of CGCs in ocular surface health, (ii) describe the ocular
surface diseases that affect CGC numbers and function, (iii) provide an update
on recent research outcomes that elucidate CGC differentiation, gene expression
and functions, and (iv) present evidence in support of the prediction that
restoring CGC numbers and/or functions is a viable strategy for alleviating
ocular surface disorders that impact the CGCs. ETHNOPHARMACOLOGICAL RELEVANCE: In Asia, Qi-Wei-Du-Qi-Wan (QWDQW) is a
traditional Chinese medicine that has been used to treat chest tightness, cough,
shortness of breath, night sweats, frequent urination and asthma. QWDQW is
recorded in Yi Zong Yi Ren Pian (Medical Physician's Compilation), which was
written by Yang Cheng Liu during the Qing Dynasty.
AIM OF THE STUDY: The traditional Chinese medicine QWDQW is composed of 7
ingredients and has been used in the treatment of asthma in Asia for hundreds of
years. However, the mechanism through which QWDQW affects the immune system in
the treatment of asthma is not known. Therefore, this study aimed to investigate
whether QWDQW alleviates asthmatic symptoms in mice with chronic asthma induced
by repeated stimulation with Dermatophagoides pteronyssinus (Der p) and to
explore the underlying immune modulatory mechanism.
MATERIALS AND METHODS: BALB/c mice were stimulated intratracheally (i.t.) with
Der p (40 μl, 2.5 μg/μl) once weekly for 6 weeks. Thirty minutes prior to Der p
stimulation, the mice were treated with QWDQW (0.5 g/kg and 0.17 g/kg) orally.
Three days after the last stimulation, the mice were sacrificed, and
infiltration of inflammatory cells, lung histological characteristics, gene
expression of lung and serum total IgE were assessed. In other experiments,
RBL-2H3 cells were stimulated with DNP-IgE/DNP-BSA and then treated with QWDQW,
quercetin, β-carotene, luteolin or a mixture of the three chemicals (Mix13) for
30 min, and the effects of the drugs on RBL-2H3 cell degranulation after DNP
stimulation were determined.
RESULTS: QWDQW significantly reduced Der p-induced airway hyperreactivity (AHR)
and decreased total serum IgE and Der p-specific IgE levels. Histopathological
examination showed that QWDQW reduced inflammatory cell infiltration and sputum
secretion from goblet cells in the lungs. Gene expression analysis indicated
that QWDQW reduced overproduction of IL-12、IFN-γ、IL-13、IL-4、RNATES、Eotaxin and
MCP-1in lung. Additionally, QWDQW and Mix13 suppressed DNP induced RBL-2H3
degranulation, and the effect was maximal when quercetin, β-carotene and
luteolin were administered together.
CONCLUSION: These results indicate that QWDQW plays a role in suppressing
excessive airway reaction and in specific immune modulation in a mouse model of
chronic asthma and that QWDQW suppresses mast cell degranulation at defined
doses of quercetin, β-carotene and luteolin. This study describes anatomical, histological and histochemical features of the
digestive tract mucosal layer of the matrinxã Brycon amazonicus, an omnivorous
freshwater fish endemic from the Amazon basin. This species presents short thick
oesophagus with longitudinal folds, that allow the passage of large food items.
The mucosa is lined with a stratified secretory epithelium rich in goblet cells
that secrete neutral and acid mucins. The two mucin types provide different
viscosity in anterior and posterior oesophagus related to the protective and
lubricant functions, respectively. The stomach is a highly distensible Y-shaped
saccular organ. Here, it is proposed that this anatomical shape plays an
essential role in food storage when food availability is abundant. The stomach
mucosa is composed of epithelial cells with intense neutral mucin secretion to
protects against gastric juice. The intestine is slightly coiled and presents
internally a complex pattern of transversal folds that increases the absorption
surface and the retention time of food. Goblet cells in the intestine secrete
acid and neutral mucins that lubricate the epithelium and aid in the digestive
processes. In the rectum, an increase in goblet cells population occurs that may
be related to better lubrication. Goblet cells (GCs) and endocrine cells (ECs) play an important role in intestine
physiology, and few studies currently exist for Amazonian fishes. This study
aimed to quantify the distribution of GCs and ECs producing cholecystokinin-8
and neuropeptide Y, assessed by mucin histochemistry and peptides
immunohistochemistry, in the intestine of two Amazonian species with different
feeding habits Tambaqui (Colossosoma macropomum) and hybrid catfish
(Pseudoplatystoma reticulatum × Leiarius marmoratus), an omnivore and carnivore,
respectively. A systematic literature review correlating feeding habit and GC
and EC distribution was also included to contribute to the comparative study.
The results of this study provided novel information about the gut cells of
Tambaqui and hybrid catfish. Both, GCs and ECs can be found sweeping the entire
intestine of Tambaqui and hybrid catfish although the cells can be more
concentrated in certain segments. The GCs and ECs in Tambaqui were more
uniformly distributed in the midgut segments (T1, T2, and T3). Unlike, in hybrid
catfish GCs were more concentrated in the hindgut (C4) and ECs mainly in the two
midgut segments (C1 and C2) of hybrid catfish. Based on the comparison between
Tambaqui, hybrid catfish, and other fishes in the literature review, we suggest
that cell distribution can be partially explained by feeding habits, carnivorous
vs. omnivorous. In asthma, goblet cell numbers are increased within the airway epithelium,
perpetuating the production of mucus that is more difficult to clear and results
in airway mucus plugging. Notch1, Notch2, or Notch3, or a combination of these
has been shown to influence the differentiation of airway epithelial cells. How
the expression of specific Notch isoforms differs in fully differentiated adult
asthmatic epithelium and whether Notch influences mucin production after
differentiation is currently unknown. We aimed to quantify different Notch
isoforms in the airway epithelium of individuals with severe asthma and to
examine the impact of Notch signaling on mucin MUC5AC. Human lung sections and
primary bronchial epithelial cells from individuals with and without asthma were
used in this study. Primary bronchial epithelial cells were differentiated at
the air-liquid interface for 28 days. Notch isoform expression was analyzed by
Taqman quantitative PCR. Immunohistochemistry was used to localize and quantify
Notch isoforms in human airway sections. Notch signaling was inhibited in vitro
using dibenzazepine or Notch3-specific siRNA, followed by analysis of MUC5AC.
NOTCH3 was highly expressed in asthmatic airway epithelium compared with
nonasthmatic epithelium. Dibenzazepine significantly reduced MUC5AC production
in air-liquid interface cultures of primary bronchial epithelial cells
concomitantly with suppression of NOTCH3 intracellular domain protein. Specific
knockdown using NOTCH3 siRNA recapitulated the dibenzazepine-induced reduction
in MUC5AC. We demonstrate that NOTCH3 is a regulator of MUC5AC production.
Increased NOTCH3 signaling in the asthmatic airway epithelium may therefore be
an underlying driver of excess MUC5AC production. |
What is OHRQoL? | The assessment of the oral health-related quality of life (OHRQoL) is possible with the Oral Health Impact Profile-14 (OHIP-14) questionnaire comprising 7 subdomains: functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap | Oral health-related quality of life (OHRQOL) in edentulous patients with
complete dentures is often impaired. This paper investigates the effect of
different coping styles on OHRQOL.
PURPOSE: (a) To assess OHRQOL of edentulous patients with conventional complete
dentures, and (b) to investigate if individual differences in these patients'
styles of coping with stress affect their OHRQOL.
MATERIALS AND METHODS: Data were collected from 249 fully edentulous patients
with complete dentures (mean age: 66.0 years) who responded to a mailed survey
(adjusted response rate: 48.8%). OHRQOL was measured with the 14-item short form
of the oral health impact profile (OHIP). Ratings of coping strategies were
obtained using the 28-item Brief COPE, an instrument measuring various styles of
coping with stress. Linear regression analyses were used to explore the
relationships between coping styles, background variables such as age, gender,
income, and age of prosthesis, and the patients' OHRQOL.
RESULTS: About 35% of the respondents reported impacts from their oral
conditions on their overall OHRQOL (OHIP-14 total score) occasionally, fairly
often, or often. Physical pain was even more prevalent, with 53.3% of the
respondents reporting pain impacts. The linear regression model (P < 0.0001)
explained 31.1% of the variation in the OHIP-14 total score. The coping
variables instrumental support, behavioral disengagement, substance abuse,
denial, and religion were significant negative predictors of OHRQOL. Only
emotional support was a significant positive predictor of OHRQOL.
CONCLUSION: Wearing conventional complete dentures has a significant impact on
OHRQOL. This impact is moderated by the styles a patient uses to cope with
stress. Using emotional support has a positive effect on OHRQOL, while other
coping styles, namely instrumental support, behavioral disengagement, substance
abuse, denial, and religion are significant negative predictors of OHRQOL. It is important to understand how people perceive the impact of oral diseases on
their quality of life. Oral health-related quality of life (OHRQOL) is a
relatively new but rapidly growing notion. The concept of OHRQOL is particularly
significant to 3 areas - clinical practice of dentistry, dental research and
dental education. There are different approaches to measure OHRQOL; the most
popular one uses multiple item questionnaires. OHRQOL should be the basis for
any oral health programme development. Moreover, research at the conceptual
level is needed in countries where OHRQOL has not been previously assessed,
including the Eastern Mediterranean countries. Oral health-related quality of life (OHRQoL) is an important aspect of health
outcomes and its assessment should be made using validated instruments. The
psychosocial impact of dental aesthetics questionnaire (PIDAQ) is an OHRQoL
instrument that assesses the psychosocial impact of dental aesthetics was
developed and validated for use on young adults. The aim of the present study
was to assess the reliability, validity, and applicability of the PIDAQ for
young adults in Brazil. After translation and cross-cultural adaptation, the
questionnaire was completed by 245 individuals (124 males and 121 females) aged
18-30 years from the city of Belo Horizonte, Brazil. In order to test
discrimit validity, the subjects were examined for the presence or absence of
malocclusion based on the dental aesthetic index criteria. Dental examinations
were carried out by a previously calibrated examiner [weighted kappa =
0.64-1.00, intraclass correlation coefficient (ICC) = 0.78-1.00]. Internal
consistency measured by Cronbach's alpha of the subscales was between 0.75 and
0.91 and test-retest reliability was assessed using the ICC, which ranged from
0.89 to 0.99 for dental self-confidence and social impact, thereby revealing
satisfactory reliability. Discrimit validity revealed that subjects without
malocclusion had different PIDAQ scores when compared with those with
malocclusion. The results suggest that the Brazilian version of the PIDAQ has
satisfactory psychometric properties and is thus applicable to young adults in
Brazil. Further research is needed to assess these properties in population
studies. Oral Health-Related Quality of Life (OHRQOL) is the shift in the perception of
health from merely the absence of disease and infirmity to complete physical,
mental and social well-being. The impact of health on the quality of life has
received more attention in recent years in both general and oral health. OHRQOL
assessments are used in oral health research, surveys and studies evaluating the
outcome of oral care. If researchers have no appropriate health-related quality
of life (HRQOL) measure in their own language, they have two options: to develop
a new measure or to modify a measure that has previously been validated in
another language which is known as a cross-cultural adaptation process. The aim
of this study is to provide guidance on how to adapt an existing measure of Oral
Health-Related Quality of Life (OHRQOL) for a different culture.
CLINICAL RELEVANCE: It is important that dental professionals should have
sufficient knowledge about Oral Health-Related Quality of Life in order to make
sure that providing the treatment focuses on the patient rather than the
disease. In addition, information about a patient's OHRQOL will make decisions
on treatment plans which are more likely to influence clinical outcomes. Oral health-related quality of life (OHRQoL) is a multidimensional construct
that measures well-being associated with the teeth, mouth, and face. This
cross-sectional study examined OHRQoL, demographic data, and clinical indicators
in 839 treatment-seeking youths with cleft from 6 geographically diverse cleft
treatment centers. Individuals without health insurance and representing ethnic
minorities had lower OHRQoL scores on the Child Oral Health Impact Profile and a
higher rate of surgical recommendations. These findings imply a risk factor for
reduced OHRQoL and unmet needs among vulnerable youths with clefts. Oral health-related quality of life (OHRQOL) is the perceived impact of one's
own oral health on daily life. Oral diseases influence children's OHRQOL
directly, but OHRQOL might also be related to oral health experiences from the
past. We investigate the relation between dental caries at the age of 6 with
OHRQOL assessed at the age of 10. This study was conducted within the Generation
R Study, a population-based prospective cohort study. Caries experience was
assessed with the decayed, missing, and filled teeth index (dmft) at a median
age of 6.09 years (90% range: 5.73-6.80). OHRQOL was assessed with a short form
of the Child Oral Health Impact Profile at the children's age of 9.79 years
(9.49-10.44). In total, 2,833 children participated in this study, of whom 472
(16.6%) had mild caries (dmft 1-3) and 228 (8.0%) had severe caries (dmft >3).
The higher the dmft score at the age of 6, the lower the OHRQOL at the age of 10
(p < 0.001). The children with severe caries at the age of 6 had significantly
higher odds of being in the lowest OHRQOL quartile at the age of 10 (OR = 1.69;
95% CI: 1.17-2.45). Our study highlights the importance of oral health during
childhood, because those who get a compromised start to oral health are much
more likely to follow a trajectory which will lead to poor oral health (-related
QOL) later. OHRQOL is not only related to current oral health experiences but
also to oral health experiences from the past. Author information:
(1)Department of Preventive Dentistry, Okayama University Graduate School of
Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku,
Okayama 700-8558, Japan. [email protected].
(2)Department of Community Oral Health, Asahi University of Dentistry, 1851-1
Hozumi, Mizuho, Gifu 501-0296, Japan. [email protected].
(3)Department of Preventive Dentistry, Okayama University Graduate School of
Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku,
Okayama 700-8558, Japan. [email protected].
(4)Department of Preventive Dentistry, Okayama University Graduate School of
Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku,
Okayama 700-8558, Japan. [email protected].
(5)Department of Preventive Dentistry, Okayama University Graduate School of
Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku,
Okayama 700-8558, Japan. [email protected].
(6)Department of Preventive Dentistry, Okayama University Graduate School of
Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku,
Okayama 700-8558, Japan. [email protected].
(7)Center of Innovative Clinical Medicine, Okayama University Hospital, Okayama
700-8558, Japan. [email protected].
(8)Department of Community Oral Health, Asahi University of Dentistry, 1851-1
Hozumi, Mizuho, Gifu 501-0296, Japan. [email protected].
(9)Department of Preventive Dentistry, Okayama University Graduate School of
Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku,
Okayama 700-8558, Japan. [email protected]. PURPOSE: Oral health-related quality of life (OHRQoL) is a construct for
assessing the self-perceived oral health of patients. The aim of this study was
to investigate the correlation between OHRQoL and orthodontic treatment need in
consideration of demographic and psychological factors.
PATIENTS AND METHODS: This multicentre study included 250 patients with an
indication for orthodontic diagnostics. In cooperation with the Institute of
Clinical Psychology at the University of Würzburg, validated and internationally
acknowledged questionnaires were selected to assess OHRQoL (COHIP-G19) and
health-related quality of life (HRQOL). Self-esteem and behavioural problems
were taken into consideration as possible psychological factors. Orthodontic
treatment need was assessed using the Index of Orthodontic Treatment Need-Dental
Health Component (IOTN-DHC), the Index of Orthodontic Treatment Need-Aesthetic
Component (IOTN-AC) and the Dental Aesthetic Index (DAI). Possible significant
correlations between the collected parameters and OHRQoL were evaluated by means
of linear regression analysis.
RESULTS: Objective orthodontic treatment need (IOTN-DHC and DAI) was
significantly correlated with OHRQoL. Further factors significantly influencing
OHRQoL in children and adolescents were age, HRQOL, self-esteem and behavioural
problems.
CONCLUSIONS: Objective orthodontic treatment need significantly influences
OHRQoL in children and adolescents. Further studies are required to investigate
if OHRQoL may be improved by correcting misaligned teeth and jaws. BACKGROUND: The Franciscan Hospital for Children Oral Health-Related Quality of
Life questionnaire (FHC-OHRQOL-Q) is an instrument designed specifically for
parents and caregivers of patients with special needs that has not yet been
applied in Spain. The aim of this study was to adapt it to Spanish and evaluate
its reliability and validity in patients with intellectual disability (ID)
treated under general anesthesia.
MATERIAL AND METHODS: The study was conducted in two different stages: a)
cross-cultural adaptation of the original questionnaire, and b) cross-sectional
study on 100 parents and caregivers who completed the piloted FHC-OHRQOL-Q. The
patients were examined according to the WHO methodology. Dental treatments
performed were recorded. Statistical tests were used to evaluate reliability
(internal consistency) and validity (content, criterion, construct and
discrimit) of the instrument.
RESULTS: The mean age was 24 years (range=4-71 years). The most frequent causes
of ID were psychomotor retardation (25%) and cerebral palsy (24%). The items
most frequently answered by parents and caregivers were eating and nutrition
problems (80%) and bad breath/taste (57%). Reliability (Cronbach's alpha
coefficient) was considered excellent (alpha=0.80-0.95). The analysis of the
factorial validity yielded similar results to the original questionnaire. The
high response rate of items (>96%) allowed content validity. Criterion validity
was confirmed by a significant correlation with questions on oral health and
oral well-being. Discrimit validity was demonstrated by the significant
association of ≥21.5 years of age with worse oral symptoms (p=0.034) and
parental concerns (p=0.005), DMFT index ≥3 with daily life problems (p=0.02), ≥4
decayed teeth with daily life problems (p=0.001), and >2 dental extractions with
oral symptoms (p=0.000), daily life problems (p=0.002) and parent's perceptions
(p=0.043).
CONCLUSIONS: The FHC-OHRQOL-Q in Spanish is a reliable and valid instrument to
apply in clinical practice to evaluate the impact of OHRQOL in mostly adult
patients with ID, accessible to Spanish-speaking parents and caregivers. STATEMENT OF PROBLEM: Oral health-related quality of life (OHRQoL) is a
subjective measure that assesses a person's perception of oral health. Patients
with Alzheimer disease (AD) suffer from impaired cognitive function and a
compromised ability to perform activities of daily living. Further exploration
is needed to clarify whether OHRQoL is negatively impacted by cognitive
degeneration and oral health conditions among patients with AD.
PURPOSE: The purpose of this systematic review was to increase understanding of
OHRQoL among patients with AD and explore factors that may affect OHRQoL.
MATERIAL AND METHODS: Searches were conducted in PubMed, the Cochrane Library
database, Medline, EBSCO, ProQuest, and EMBASE until August 30, 2018, with no
date restrictions. The initial search targeted quantitative observational
studies published in English that included the keywords AD, oral, prosthesis,
and OHRQoL. Data extraction was independently conducted by 2 reviewers. OHRQoL
was investigated as the outcome. Cognitive status and oral health conditions
were treated as exposures. Tools used to measure OHRQoL included the Geriatric
Oral Health Assessment Index (GOHAI) and the Oral Health Impact Profile. The
research adhered to the Preferred Reporting Items for Systematic Reviews and
Meta-Analyses guidelines.
RESULTS: Six studies were included. The sample sizes ranged from 30 to 226
participants, 5 studies used cross-sectional designs, and 1 was a nonrandomized
controlled trial. Three studies reported higher OHRQoL scores among participants
with AD than those among controls, but only 1 study showed a statistically
significant difference. A statistical analysis was conducted with 4 studies that
reported GOHAI scores, and no significant differences were found in GOHAI scores
between participants with AD and controls (standard mean difference: 0.09; 95%
confidence interval: -0.66 to 0.85). All studies that explored factors affecting
OHRQoL showed different associations between cognitive impairment, oral health
conditions, and OHRQoL. One study showed that cognitive impairment was
negatively associated with OHRQoL. Three studies found oral health conditions
(including periodontitis, gingival bleeding, probing depth >4 mm, and number of
natural teeth) impaired the OHRQoL of participants with AD. Three studies
reported that prosthetic type and quality positively affected OHRQoL among
participants with AD.
CONCLUSIONS: OHRQoL may not fully represent actual oral health problems of
patients with AD. Clinical dentists should evaluate oral problems in this
population, preferably by using both subjective and objective examinations,
including oral and dental conditions. This will ensure oral problems among
patients with AD can be detected early and timely treatment provided. BACKGROUND: There is a lack of cohort studies on the influence factors of oral
health-related quality of life (OHRQoL). This study aimed to follow subjects
from age 12 to 18 to analyse the sociodemographic and clinical factors that may
influence OHRQoL.
METHODS: This cohort study selected a representative sample from Hong Kong.
Periodontal status and caries were examined according to WHO criteria. Four
orthodontic indices were used to assess malocclusion. Child Perceptions
Questionnaires (CPQ11-14) with 8 items (CPQ11-14-ISF: 8) and 37 items were used
to assess OHRQoL at age 12 and age 15, respectively; Oral Health Impact Profile
(OHIP-14) was used to assess OHRQoL at age 18. Wilcoxon signed ranks test and
Friedman's test were used to analyse the age-related change of OHRQoL and
malocclusion from age 12 to 18. Generalized estimating equations were used to
analyse the influence factors of OHRQoL and to calculate adjusted risk ratio
(RR).
RESULTS: Subjects recruited in this study were 589 (305 females, 284 males), 364
(186 females, 178 males) and 300 (165 females, 135 males) at age 12, 15 and 18,
respectively. Among them, 331 subjects (172 females, 159 males) were followed
from age 12 to 15, and 118 subjects (106 females, 82 males) were followed from
age 12 to 18. Subjects had less severe malocclusion at age 12 than at ages 15
and 18 (p = 0.000, measured by Dental Aesthetic Index). Age, periodontal status,
and malocclusion had an effect on OHRQoL. When compared with OHRQoL at age 12,
worse OHRQoL was observed at age 15 (adjusted RR = 1.06, 95%CI = 1.01-1.12,
p = 0.032), but not at age 18 (adjusted RR = 1.01, 95%CI = 0.95-1.08,
p = 0.759). Unhealthy periodontal conditions had a negative effect on OHRQoL
(adjusted RR = 1.14, 95%CI = 1.04-1.25, p = 0.007). Only severe malocclusions
had a negative effect on OHRQoL; a more severe malocclusion was associated with
a higher effect on OHRQoL (adjusted RR = 1.09, 95%CI = 1.01-1.18, p = 0.032 for
severe malocclusion, and adjusted RR = 1.17, 95%CI = 1.07-1.28, p = 0.001 for
very severe malocclusion measured by Dental Aesthetic Index).
CONCLUSION: Age, periodontal status, and malocclusion had an influence on OHRQoL
from age 12 to 18. When clinicians attempt to improve subjects' OHRQoL, it is
necessary to consider these factors. Esthetics in the oro-facial region are important for perceived oral health and a
common reason for treatment of discoloured, missing or crowded teeth. As one of
the fundamental bricks of a patient's oral health, changes in the domain of
oro-facial esthetics resides within the oral health-related quality of life
(OHRQoL) of an individual. Four main dimensions, oral function, oro-facial pain,
oro-facial appearance and psychosocial impact, are suggested to cover the
concept of OHRQoL. The aim of this systematic review was to map the impact from
oral conditions with principal impact on the oro-facial appearance dimension of
OHRQoL (PROSPERO: CRD42017064033). Publications were included if they reported
Oral Health Impact Profile (OHIP) mean or median domain scores for patients with
esthetic treatment need relating to tooth wear, orthodontics, orthognathic
surgery, frontal tooth loss or tooth whitening. A search in PubMed (Medline),
EMBASE, Cochrane, CINAHL and PsycINFO 8 June 2017 and updated 14 January 2019,
identified 2,104 abstracts. After screening of abstracts, 1607 articles were
reviewed in full text and 33 articles included. These 33 articles reported
OHIP-data for 9409 patients grouped in 63 patient populations. Median oro-facial
appearance impact scores on a standardised 0-8 scale, for populations with
treatment need relating to tooth wear, orthodontics, orthognathic surgery,
frontal tooth loss and tooth whitening, ranged from 0.13 for tooth wear to 3.04
for tooth whitening populations. In conclusion, a moderate impact for the
oro-facial appearance dimension of OHRQoL was found in patients with different
conditions with esthetically related treatment need. BACKGROUND: Oral health-related quality of life (OHRQoL) is a multidimensional,
perception-based measure of how oral health affects social and physical
functioning and self-image. OHRQoL is important for assessing women living with
HIV (WLWH) who may have unmet dental needs and experience disparities that
impact dental care accessibility.
METHODS: In 2016, the authors conducted an assessment of OHRQoL among a national
sample of 1,526 WLWH in the Women's Interagency HIV Study using the Oral Health
Impact Profile instrument, which assesses the frequency of 14 oral health impact
items. OHRQoL was measured using multivariable linear regression with a negative
binomial distribution to assess the association between report of a recent unmet
dental need and OHRQoL.
RESULTS: "Fair or poor" oral health condition was reported by 37.8% (n = 576) of
WLWH. Multivariable linear regression showed that unmet dental needs had the
strongest positive association with poor OHRQoL (difference in Oral Health
Impact Profile mean, 2.675; P < .001) compared with not having unmet needs. The
frequency of dental care utilization was not associated with higher OHRQoL.
Older age, fair or poor dental condition, smoking, symptoms of anxiety and
loneliness, and poor OHRQoL were also associated with worse OHRQoL.
CONCLUSION: Self-perceived impact of oral health on social and physical function
and self-image, as measured by OHRQoL, may be an easily assessable but
underrecognized aspect of OHRQoL, particularly among women aging with HIV.
PRACTICAL IMPLICATIONS: Dentists should implement OHRQoL assessments in their
management of the care of patients with HIV to identify those who do have
significant oral health impacts. Oral health-related quality of life (OHRQOL) is the component of health-related
quality of life that relates to the effects of oral diseases and dental
interventions on patients. This article describes why OHRQOL is important and
how it is measured. The conceptual basis for OHRQOL is discussed. A
four-dimensional structure consisting of Oral Function, Orofacial Pain,
Orofacial Appearance and Psychosocial Impact as the OHRQOL dimensions has
emerged as psychometrically sound and clinically intuitive. Consequently, when
the impact of oral diseases or the effects of dental interventions are measured,
four dimension scores capturing these attributes need to be used. This cross-sectional study compared the Oral-Health-Related Quality of Life
(OHRQoL) in HIV negative patients (Group 1, n=129, mean age: 39.9 ± 15.6, 75
females) and HIV+ patients (Group 2, n=670, mean age: 43.2 ± 9.8, 246 females)
from the same socio-economic environment using the OHIP-49 questionnaire. OHIP
total score were determined by simple summing. A multiple linear regression
model was carried out to predict OHIP scores in which HIV+ patients experienced
a significantly (p<0.001) worst OHRQoL for total and every dimension. A general
linear model was used for estimating the means in the two groups adjusted for
covariates included in the previous model. Adjusted means for subscale and total
OHIP scores were significantly higher for Group 2 (61.6 ± 6.26 vs. 119.8 ± 3.31)
with a large effect size (0.94). HIV+ infection, decayed teeth, prosthodontic
and surgical needs, care index, drug use, employment and age presented an
independent effect on questionnaire scores. This study shows that HIV+ infection
has an independent and negative impact on the OHRQoL while care index presents a
positive impact. Additional factors like high decayed teeth, prosthodontic
treatment needs and drug use are independently associated with total OHIP
scores, presenting a negative effect on OHRQoL. BACKGROUND: The expatriate workers (foreign workers) come from various countries
having different languages, cultures, and tradition to work in Kingdom of Saudi
Arabia (KSA); here they adopt to local customs, traditions, and work ethics in
this new environment. How they perceive their oral health-related quality of
life (OHRQoL) is important for health-care provider for understanding and
planning in patient management. The data of expat workers and their OHRQoL in
KSA are meager; hence, assessment of OHRQoL among expatriate working population
in Al Zulfi, Saudi Arabia was planned.
MATERIALS AND METHODS: A cross-sectional study was conducted on adult expat
working population of various nationalities who were working in Al Zulfi, KSA.
The study sample comprised 600 adult expats. OHRQoL was analyzed by using
14-Item Oral Health Impact Profile (OHIP-14) questionnaire as instrument.
Clinical examination for oral health status was carried out using decayed,
missing, and filled teeth (DMFT) index and Oral Hygiene Index simplified
(OHI-S). Student's t test and analysis of variance (ANOVA) were used to compare
data using Statistical Package for the Social Sciences (SPSS) software program,
version 20.0 with significance at P ≤ 0.05.
RESULTS: The age of the sample population ranged from 19 to 60 years. No
significant difference was observed in oral health status among expats of
different nationalities. Age and education were significantly related to OHRQoL
as well as oral health status. The mean cumulative scores of OHIP-14 showed that
expats from different nationalities had statistically significant differences.
CONCLUSION: Overall the impact of OHRQoL was less among working expat population
in Al Zulfi. Physical pain was the common dimension seen among all
nationalities. Psychological discomfort and handicap dimensions of OHIP-14 were
significant among the study sample. This study aimed to describe different approaches for the evaluation of the Oral
health-related quality of life (OHRQoL) of preschool children and to discuss
perspectives for future instruments. The OHRQoL is a concept that surpasses an
exclusively clinical perception and includes functional, social, emotional, and
environmental issues. The measure of OHRQoL represents a holistic approach for
researchers and clinicians extending their visions beyond the mouth and
understanding the entire context of the patient. Negative impacts of oral
conditions on OHRQoL in childhood can reflect on health development, especially
in a life stage marked by social and cognitive maturation. Instruments have been
developed and cross-culturally adapted to evaluate the impact of oral conditions
on the OHRQoL of preschool children and their families. Some features
distinguish these instruments and influence their selection, such as: self- or
proxy-report; generic- or specific-condition; long- or short-form, and less or
more established used in literature. Moreover, theoretical framework, construct
validation and availability should also be considered. Nine OHRQoL instruments
for preschool children were included in the present literature review. They were
created between 2003 and 2017 by developed countries in most cases. The shorter
instrument has five items, and the larger has 31 items. Most of them are
proxy-reported, generic-condition, and have been relatively well established in
the literature. The diversity of instruments indicates the evolution of OHRQoL
studies, but there are methodological issues still in need to be improved in
future developments or cross-cultural adaptations, according to current
psychometric evidence. PURPOSE: To compare oral health-related quality of life (OHRQoL) and masticatory
performance (MP) in patients treated with a mandibular complete denture (CD) and
immediately loaded implant-supported prostheses (ISP).
MATERIALS AND METHODS: Forty patients were divided into CD and ISP groups.
Initially, all patients were treated with a mandibular CD. Then, 23 patients
remained with a CD while 17 patients were treated with an ISP after wearing the
CD for 3 months. OHRQoL was measured using the OHIP-EDENT questionnaire, and MP
was evaluated by sieving. Data were recorded before treatment (T0) and after 3
months wearing the CD and ISP (T1).
RESULTS: CD treatment did not affect OHRQoL and PM; however, patients treated
with an ISP presented improvement in OHRQoL (P < .001) and MP (P < .001) with a
high effect size (ES) (Cohen's d = 2.49 and 2.47, respectively). For intergroup
analysis, ISP treatment presented improvement in OHRQoL and MP compared to CD
treatment (P < 0.001) at T1 with a high ES (Cohen's d = 1.80 and 3.29,
respectively). The correlation between MP and OHRQoL was positive only for
psychologic discomfort in the CD group at T0 (P = .035), suggesting that poor MP
increased psychologic discomfort.
CONCLUSION: Converting a CD into an ISP had a positive impact on OHRQoL and MP
with high ES. PURPOSE: To evaluate the performance of complete dentures (CD) with anatomical
and noatomical teeth in completely edentulous elderly individuals regarding
oral health-related quality of life (OHRQoL), satisfaction, masticatory
performance (MP), need for adjustment after CD placement, and patient preference
for occlusal type.
MATERIALS AND METHODS: A randomized crossover clinical trial comprising 50
edentulous elderly individuals was conducted. The participants were divided into
two groups: AT-NT (rehabilitated initially with anatomical teeth and 3 months
later with noatomical teeth) and NT-AT (rehabilitated initially with
noatomical teeth and 3 months later with anatomical teeth). OHRQoL was
analyzed using the OHIP-EDENT; a satisfaction questionnaire was applied; MP was
evaluated by the median particle size (×50) after chewing an artificial test
food; and the number of adjustments of the prosthesis base was assessed
quantitatively.
RESULTS: Overall, 34 elderly individuals (mean age: 69 years) were analyzed. No
significant difference was observed between CD users with anatomical and
noatomical teeth for OHRQoL (P = .674), satisfaction (P = .725), MP (P =
.849), or number of adjustments (P = .135). Most subjects (52.9%) did not
express a preference for any occlusal surface type. However, among those with a
preference, the majority (32.4%) opted for noatomical teeth.
CONCLUSION: Both posterior tooth types are eligible for oral rehabilitation in
elderly users of conventional CDs, as the variables were not influenced by
occlusal morphology. However, further studies are warranted in highly resorbed
mandibular edges or in cases of adaptation difficulties, as the results may
differ. OBJECTIVE: To assess oral health-related quality of life (OHRQoL) changes before
and after the primary surgical treatment in infants with cleft lip and/or palate
(CL/P).
DESIGN: Quasi-experimental study.
METHODS: A total of 106 infants with CL/P younger than 2 years undergoing
primary surgical treatment in the Plastic Surgery Service of the Instituto
Nacional de Salud del Niño in Peru. The parent/caregiver answered a
questionnaire about OHRQoL named the Peruvian version of the Early Childhood
Oral Health Impact Scale (P-ECOHIS) in the pretreatment (baseline) and follow-up
post-treatment. The total score of P-ECOHIS and their 2 sections (child impact
and family impact) in the baseline and each follow-up period post-treatment
scores were assessed. As well as, the type of the CL/P on OHRQoL, standardized
effect sizes (ES) based on mean total change scores (difference between baseline
and 12th month) were analyzed.
RESULTS: Improvements in infant's OHRQoL after treatment were reflected in each
follow-up period P-ECOHIS score compared to the baseline score. The total
P-ECOHIS scores decreased significantly from 28.07 (baseline) to 7.7 (12th
month; P < .0001), as did the individual domain scores (P < .0001). There were
significant differences in the baseline and follow-up post-treatment scores of
infants who reported improvement of the OHRQoL (P < .0001). The ES was large
(3.79). The cleft lip had an improvement in the OHRQoL at 12th month
post-treatment (P < .0001).
CONCLUSIONS: Primary surgical post-treatment resulted in significant improvement
of the infant's OHRQoL with CL/P. |
Which VKORC1 genotypes are associated with a need for lower warfarin maintenance dose? | Patients with VKORC1-1639GA or AA required a lower warfarin maintenance dose. | Author information:
(1)Division of Clinical Pharmacology and Toxicology, The Hospital for Sick
Children, Toronto, ON, Canada.
(2)Department of Pediatrics, Yokohama City University, School of Medicine,
Yokohama, Kanagawa, Japan.
(3)Division of Clinical Research Planning, Department of Development Strategy,
Center for Clinical Research and Development, National Center for Child Health
and Development, Tokyo, Japan.
(4)Institute of Cellular Medicine, Newcastle University and Newcastle upon Tyne
Hospitals, NHS Foundation Trust, Newcastle upon Tyne, UK.
(5)Department of Haematology, The Newcastle upon Tyne Hospitals NHS Foundation
Trust, Newcastle upon Tyne, UK.
(6)Division of Pediatric Hematology/Oncology/BMT, Nationwide Children's
Hospital, Columbus, OH, US.
(7)Division of Pediatric Hematology/Oncology, Department of Pediatrics, Monroe
Carell Jr. Children's Hospital at Vanderbilt, Vanderbilt University Medical
Center, Nashville, TN, US.
(8)Assistance Publique Hôpitaux de Paris, Hôpital Necker Enfants Malades, Unité
Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, Centre de
référence M3C, Paris, France.
(9)University Paris Descartes, Paris, France.
(10)Université Paris Descartes, Inserm Unité Mixte de Recherche (UMR)-S, Paris,
France.
(11)University Paris Descartes, INSERM UMR 1147, Paris, France.
(12)Influenza and Emerging Respiratory Pathogens, BC Centre for Disease Control,
Vancouver, BC, Canada.
(13)Division of Translational Therapeutics, Department of Pediatrics, University
of British Columbia, Vancouver, BC, Canada.
(14)Department of Medical Sciences, Clinical Pharmacology and Science for Life
Laboratory, Uppsala University, Uppsala, Sweden.
(15)Department of Pediatrics, Graduate School of Medicine and Pharmaceutical
Sciences, University of Toyama, Toyama, Japan.
(16)Graduate School of Medicine and Pharmaceutical Sciences, University of
Toyama, Toyama, Japan.
(17)Department of Cardiology, Kanagawa Children's Medical Center, Yokohama,
Japan.
(18)Department of Pediatrics, Tokyo Medical and Dental University, Tokyo, Japan.
(19)Department of Clinical Pharmacology & Genetics, School of Pharmaceutical
Sciences, University of Shizuoka, Shizuoka, Japan.
(20)Division of Pediatric Hematology/Oncology, The Hospital for Sick Children,
Toronto, ON, Canada.
(21)Division of Clinical Pharmacology and Toxicology, The Hospital for Sick
Children, Toronto, ON, Canada. [email protected]. |
Which R/bioconductor have been developed for copy number analysis? | CNVRanger, seqCNA, iGC, PLRS, SomatiCA, Copynumber, crlmm, KC-SMARTR are all R/bioconductor packages for copy number analysis | SUMMARY: DNA copy number and mRNA expression are commonly used data types in
cancer studies. Available software for integrative analysis arbitrarily fixes
the parametric form of the association between the two molecular levels and
hence offers no opportunities for modelling it. We present a new tool for
flexible modelling of this association. PLRS uses a wide class of interpretable
models including popular ones and incorporates prior biological knowledge. It is
capable to identify the gene-specific type of relationship between gene copy
number and mRNA expression. Moreover, it tests the strength of the association
and provides confidence intervals. We illustrate PLRS using glioblastoma data
from The Cancer Genome Atlas.
AVAILABILITY AND IMPLEMENTATION: PLRS is implemented as an R package and
available from Bioconductor (as of version 2.12; http://bioconductor.org).
Additional code for parallel computations is available as Supplementary
Material.
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics
online. Whole genome sequencing of matched tumor-normal sample pairs is becoming routine
in cancer research. However, analysis of somatic copy-number changes from
sequencing data is still challenging because of insufficient sequencing
coverage, unknown tumor sample purity and subclonal heterogeneity. Here we
describe a computational framework, named SomatiCA, which explicitly accounts
for tumor purity and subclonality in the analysis of somatic copy-number
profiles. Taking read depths (RD) and lesser allele frequencies (LAF) as input,
SomatiCA will output 1) admixture rate for each tumor sample, 2) somatic allelic
copy-number for each genomic segment, 3) fraction of tumor cells with subclonal
change in each somatic copy number aberration (SCNA), and 4) a list of
substantial genomic aberration events including gain, loss and LOH. SomatiCA is
available as a Bioconductor R package at
http://www.bioconductor.org/packages/2.13/bioc/html/SomatiCA.html. BACKGROUND: Deviations in the amount of genomic content that arise during
tumorigenesis, called copy number alterations, are structural rearrangements
that can critically affect gene expression patterns. Additionally, copy number
alteration profiles allow insight into cancer discrimination, progression and
complexity. On data obtained from high-throughput sequencing, improving quality
through GC bias correction and keeping false positives to a minimum help build
reliable copy number alteration profiles.
RESULTS: We introduce seqCNA, a parallelized R package for an integral copy
number analysis of high-throughput sequencing cancer data. The package includes
novel methodology on (i) filtering, reducing false positives, and (ii) GC
content correction, improving copy number profile quality, especially under
great read coverage and high correlation between GC content and copy number.
Adequate analysis steps are automatically chosen based on availability of
paired-end mapping, matched normal samples and genome annotation.
CONCLUSIONS: seqCNA, available through Bioconductor, provides accurate copy
number predictions in tumoural data, thanks to the extensive filtering and
better GC bias correction, while providing an integrated and parallelized
workflow. BACKGROUND: With the advancement in high-throughput technologies, researchers
can simultaneously investigate gene expression and copy number alteration (CNA)
data from individual patients at a lower cost. Traditional analysis methods
analyze each type of data individually and integrate their results using Venn
diagrams. Challenges arise, however, when the results are irreproducible and
inconsistent across multiple platforms. To address these issues, one possible
approach is to concurrently analyze both gene expression profiling and CNAs in
the same individual.
RESULTS: We have developed an open-source R/Bioconductor package (iGC). Multiple
input formats are supported and users can define their own criteria for
identifying differentially expressed genes driven by CNAs. The analysis of two
real microarray datasets demonstrated that the CNA-driven genes identified by
the iGC package showed significantly higher Pearson correlation coefficients
with their gene expression levels and copy numbers than those genes located in a
genomic region with CNA. Compared with the Venn diagram approach, the iGC
package showed better performance.
CONCLUSION: The iGC package is effective and useful for identifying CNA-driven
genes. By simultaneously considering both comparative genomic and transcriptomic
data, it can provide better understanding of biological and medical questions.
The iGC package's source code and manual are freely available at
https://www.bioconductor.org/packages/release/bioc/html/iGC.html . SUMMARY: Copy number variation (CNV) is a major type of structural genomic
variation that is increasingly studied across different species for association
with diseases and production traits. Established protocols for experimental
detection and computational inference of CNVs from SNP array and next-generation
sequencing data are available. We present the CNVRanger R/Bioconductor package
which implements a comprehensive toolbox for structured downstream analysis of
CNVs. This includes functionality for summarizing individual CNV calls across a
population, assessing overlap with functional genomic regions, and genome-wide
association analysis with gene expression and quantitative phenotypes.
AVAILABILITY AND IMPLEMENTATION: http://bioconductor.org/packages/CNVRanger. |
Is gabapentin effective for chronic pelvic pain? | Based on data from multicentre, randomised, double-blind, placebo-controlled trial (GaPP2), treatment with gabapentin did not result in significantly lower pain scores in women with chronic pelvic pain, and was associated with higher rates of side-effects than placebo. | BACKGROUND: Chronic pelvic pain affects 2-24% of women worldwide and evidence
for medical treatments is scarce. Gabapentin is effective in treating some
chronic pain conditions. We aimed to measure the efficacy and safety of
gabapentin in women with chronic pelvic pain and no obvious pelvic pathology.
METHODS: We performed a multicentre, randomised, double-blind,
placebo-controlled randomised trial in 39 UK hospital centres. Eligible
participants were women with chronic pelvic pain (with or without dysmenorrhoea
or dyspareunia) of at least 3 months duration. Inclusion criteria were 18-50
years of age, use or willingness to use contraception to avoid pregcy, and no
obvious pelvic pathology at laparoscopy, which must have taken place at least 2
weeks before consent but less than 36 months previously. Participants were
randomly assigned in a 1:1 ratio to receive gabapentin (titrated to a maximum
dose of 2700 mg daily) or matching placebo for 16 weeks. The online
randomisation system minimised allocations by presence or absence of
dysmenorrhoea, psychological distress, current use of hormonal contraceptives,
and hospital centre. The appearance, route, and administration of the assigned
intervention were identical in both groups. Patients, clinicians, and research
staff were unaware of the trial group assignments throughout the trial.
Participants were unmasked once they had provided all outcome data at week
16-17, or sooner if a serious adverse event requiring knowledge of the study
drug occurred. The dual primary outcome measures were worst and average pain
scores assessed separately on a numerical rating scale in weeks 13-16 after
randomisation, in the intention-to-treat population. Self-reported adverse
events were assessed according to intention-to-treat principles. This trial is
registered with the ISRCTN registry, ISCRTN77451762.
FINDINGS: Participants were screened between Nov 30, 2015, and March 6, 2019,
and 306 were randomly assigned (153 to gabapentin and 153 to placebo). There
were no significant between-group differences in both worst and average
numerical rating scale (NRS) pain scores at 13-16 weeks after randomisation. The
mean worst NRS pain score was 7·1 (standard deviation [SD] 2·6) in the
gabapentin group and 7·4 (SD 2·2) in the placebo group. Mean change from
baseline was -1·4 (SD 2·3) in the gabapentin group and -1·2 (SD 2·1) in the
placebo group (adjusted mean difference -0·20 [97·5% CI -0·81 to 0·42]; p=0·47).
The mean average NRS pain score was 4·3 (SD 2·3) in the gabapentin group and 4·5
(SD 2·2) in the placebo group. Mean change from baseline was -1·1 (SD 2·0) in
the gabapentin group and -0·9 (SD 1·8) in the placebo group (adjusted mean
difference -0·18 [97·5% CI -0·71 to 0·35]; p=0·45). More women had a serious
adverse event in the gabapentin group than in the placebo group (10 [7%] of 153
in the gabapentin group compared with 3 [2%] of 153 in the placebo group;
p=0·04). Dizziness, drowsiness, and visual disturbances were more common in the
gabapentin group.
INTERPRETATION: This study was adequately powered, but treatment with gabapentin
did not result in significantly lower pain scores in women with chronic pelvic
pain, and was associated with higher rates of side-effects than placebo. Given
the increasing reports of abuse and evidence of potential harms associated with
gabapentin use, it is important that clinicians consider alternative treatment
options to off-label gabapentin for the management of chronic pelvic pain and no
obvious pelvic pathology.
FUNDING: National Institute for Health Research. |
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