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7789305
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Expression of gonadotropin-releasing hormone (GnRH) receptor gene is altered by GnRH agonist desensitization in a manner similar to that of gonadotropin beta-subunit genes in normal and castrated rat pituitary.
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It was previously established that the administration of a potent GnRH agonist such as triptorelin (D-Trp6-GnRH) induced desensitization of pituitary gonadotropic cells, resulting in decreased expression of gonadotropin beta-subunit genes and the suppression of LH and FSH synthesis and release. Binding of GnRH to the pituitary is also affected by agonist treatment. To examine the desensitizing effects of GnRH agonist on the expression of the pituitary GnRH receptor (GnRH-R) gene, male rats were given triptorelin (long-acting formulation, 300 micrograms/kg), and levels of GnRH-R messenger RNA (mRNA) were determined by Northern and dot blot hybridization to a 32P-labeled rat complementary DNA probe. Abundances of gonadotropin alpha-subunit, LH beta, and FSH beta mRNAs were examined in parallel, using appropriate probes. A rapid time-dependent decrease in the level of GnRH-R mRNA was observed in rats after triptorelin administration. A minimum residual level of mRNA, in the range of 20-25% of the initial value, was attained as early as 5 h after treatment. Levels further stabilized to 25-30% after a small transient increase to 45% on day 5. A single injection was effective for at least 30 days, after which GnRH-R mRNA levels slowly returned to normal, suggesting a progressive abolition of agonist effects. A concomitant acute depletion of mRNA levels was observed for LH beta and FSH beta (50% decrease in about 48 and 3 h, respectively), whereas the alpha-subunit message increased (rapidly reaching a level 1.8-fold that in control rats after 1-2 days). Castration induced a 3.8-fold elevation in the amounts of GnRH-R mRNA after 3 weeks, whereas alpha, LH beta, and FSH beta mRNAs increased by 6.2-, 7.9-, and 4.2-fold, respectively, compared to corresponding values in intact animals. Administration of the GnRH agonist readily prevented, for as long as 3 weeks, the stimulatory effects of castration on the GnRH-R mRNA and mRNAs for the beta-subunit of gonadotropins, but not for the alpha mRNA, which remained at a high level. When triptorelin was administered 3 weeks postoperatively, the castration-induced increase in LH beta and FSH beta was totally abolished, and no significant effect was noted on alpha-subunit mRNA. In conclusion, these data demonstrate that expression of the GnRH-R gene is subject to regulation and depends on GnRH stimulation, in a manner that indicates susceptibility to desensitizing action by the long-acting GnRH analog, triptorelin.(ABSTRACT TRUNCATED AT 400 WORDS)
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7789304
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Changes in adrenal status affect hypothalamic thyrotropin-releasing hormone gene expression in parallel with corticotropin-releasing hormone.
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Glucocorticoids are well known to influence the secretion of TSH from the anterior pituitary gland, although it is uncertain whether its site of action is on the hypothalamus, pituitary, or both. To determine whether glucocorticoids can modulate the concentration of pro-TRH gene expression in hypothalamic hypophysiotropic neurons, we measured the content of pro-TRH messenger RNA (mRNA) in the paraventricular nucleus (PVN) of adrenalectomized and corticosterone- and dexamethasone-treated rats compared to that in control populations using in situ hybridization histochemistry. Adrenalectomy resulted in the expected increase in corticotropin-releasing hormone mRNA in the PVN and was accompanied by a parallel rise in pro-TRH mRNA (68.3%; P < 0.05). Conversely, corticosterone and dexamethasone both resulted in profound reduction in corticotropin-releasing hormone mRNA in the PVN and a parallel reduction in pro-TRH mRNA (43.2% and 73.2% respectively; P < 0.05). No significant differences were observed in pro-TRH mRNA in the lateral hypothalamus in any of the groups. These data suggest that glucocorticoids can influence the concentration of pro-TRH mRNA in a cell-specific manner and thereby could result in changes in the biosynthesis and release of TRH in hypophysiotropic neurons of the PVN.
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7789292
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Isradipine. An update of its pharmacodynamic and pharmacokinetic properties and therapeutic efficacy in the treatment of mild to moderate hypertension.
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Since the earlier review in Drugs substantial additional data have accumulated regarding the antihypertensive efficacy of isradipine in various clinical situations, as well as data on its clinical effects in atherosclerosis. Recent therapeutic trials confirm that the efficacy of isradipine in the treatment of patients with mainly mild to moderate hypertension, when administered orally as a conventional or modified release preparation, is similar to that of titrated dosages of amlodipine, felodipine, nifedipine, diltiazem, captopril, methyldopa, metoprolol, prazosin and hydrochlorothiazide. A further decrease in blood pressure can be expected when isradipine is combined with another antihypertensive drug in patients who have not responded adequately to monotherapy. Initial studies have shown that intravenous isradipine is effective in controlling hypertension following coronary artery bypass graft surgery and that it appears useful in the treatment of intraoperative hypertension and hypertensive crisis, and in hypertensive disorders in pregnancy, when administered orally or intravenously. A large study, the Multicentre Isradipine Diuretic Atherosclerosis Study (MIDAS), was designed to compare the efficacy of isradipine and hydrochlorothiazide in reducing the rate of progression of carotid artery wall thickness, measured by B-mode ultrasound, as a surrogate for early atherosclerosis. Results indicated that wall thickness increased significantly less with isradipine than hydrochlorothiazide after 6 months of therapy. Thereafter the rate of progression remained parallel for the remainder of the 3-year trial. The confirmation of its antihypertensive efficacy, along with its favourable haemodynamic profile and reversal of left ventricular hypertrophy, minimal effect on glucose and lipid metabolism, preservation of quality of life and good tolerability, makes isradipine a suitable drug for the treatment of most patients with mild to moderate hypertension.
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7789290
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Trimetrexate. A review of its pharmacodynamic and pharmacokinetic properties and therapeutic potential in the treatment of Pneumocystis carinii pneumonia.
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Trimetrexate is a folinic acid analogue structurally related to methotrexate, whose primary mechanism of action is believed to be inhibition of dihydrofolate reductase. This reduces the production of DNA and RNA precursors and leads to cell death. Trimetrexate is lipophilic and can passively diffuse across cell membranes including those of Pneumocystis carinii and its mammalian host. To minimise toxicity, trimetrexate must be coadministered with calcium folinate (leucovorin calcium), a reduced folate coenzyme, which is transported into, and protects, mammalian host cells but not P. carinii cells. In noncomparative trials trimetrexate was effective in the treatment of P. carinii pneumonia (PCP) in patients with AIDS who were intolerant of or refractory to cotrimoxazole (trimethoprim/sulfamethoxazole) and pentamidine treatment. In these patients, 2- to 4-week survival rates of 48 to 69% were reported. In a comparative trial in the initial therapy of PCP, trimetrexate was less effective than cotrimoxazole in moderate to severe disease as evidenced by a significantly higher failure rate. Trimetrexate was better tolerated than cotrimoxazole when used in this setting, however. Significantly fewer patients receiving trimetrexate plus calcium folinate discontinued treatment because of adverse events than did patients receiving cotrimoxazole. The most common adverse effect associated with trimetrexate is myelosuppression (neutropenia and thrombocytopenia); this is mitigated by coadministration of calcium folinate and is generally reversible upon dosage reduction or discontinuation. Other adverse effects include increases in serum aminotransferase levels, anaemia, fever, rash/pruritus, and increased alkaline phosphatase or serum creatinine levels. Further research into the use of trimetrexate, including its efficacy as prophylaxis, in combination with other agents and as an oral formulation, is needed to clearly define its role in the treatment of PCP and to identify patients most likely to benefit. Currently, trimetrexate should be considered as an alternative treatment option in immunocompromised patients with moderate to severe PCP who have not responded to or are intolerant of first-line therapy.
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7789286
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Choosing the right ACE inhibitor. A guide to selection.
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To find out if there are one or more criteria to guide selection among the ACE inhibitors for the treatment of arterial hypertension, we have reviewed the principal pharmacokinetic and pharmacodynamic aspects of the more frequently used agents of this class of antihypertensive drugs. Among the pharmacokinetic aspects that we have considered, terminal half-life, as related to the duration of the antihypertensive effect, and the route of elimination may have an impact in the clinical selection among the various ACE inhibitors. On the other hand, all the other characteristics have no pragmatic clinical relevance or may be corrected by dosage adjustment. Among the pharmacodynamic aspects, the antihypertensive efficacy of the different ACE inhibitors seems to be very similar, and some of the differences found in different studies are probably due to the population investigated and to the protocol of the study (time of blood pressure measurements, diet, drug dosage etc.). However, some differences can be found among the various ACE inhibitors when the antihypertensive efficacy is evaluated also as trough to peak ratio of blood pressure reduction. Indeed, in respect of the administration schedule of each ACE inhibitor not all the agents of this class have a trough to peak ratio above 50 to 60%, as suggested by the Food and Drug Administration of the US. According to this criterion, especially when blood pressure is measured with 24-hour noninvasive ambulatory blood pressure monitoring, some drugs such as lisinopril, enalapril and trandolapril should be preferred for their higher trough to peak ratios. Left ventricular hypertrophy is significantly reduced by antihypertensive agents, the ACE inhibitors being the most effective. Indeed, the reduction of left ventricle mass for each 1 mm Hg reduction in mean blood pressure is greater for ACE inhibitors than for other classes of antihypertensive agents. However, this effect seems more class related than characteristic of one or more among the various ACE inhibitors. Insulin resistance is elevated in hypertensive patients and it has been thought responsible for or associated with other metabolic abnormalities. ACE inhibitors seem to correct the insulin resistance of hypertensive patients, but this effect also appears to be class related more than limited to one ACE inhibitor or another. Our knowledge of this field is still limited and more studies are necessary, especially to understand the prognostic impact of insulin resistance and/or insulin resistance improvement.(ABSTRACT TRUNCATED AT 400 WORDS)
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7789289
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Hypertension in pregnancy. Practical management recommendations.
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Hypertension is a common and potentially serious complication of human pregnancy. It can be a marker of underlying maternal disease processes aggravated by pregnancy, or it can be directly related to the pregnancy (pre-eclampsia). It is associated with increased risks of fetal growth retardation and, if severe, can cause both maternal and fetal problems. The risks to both mother and neonate can be reduced by appropriate supervision and therapy. Close monitoring of maternal and fetal welfare will help to determine the optimum time for delivery. Maternal hypertension should be controlled with agents considered to be well tolerated in pregnancy. Following the index pregnancy, all patients with early and/or severe hypertension should be investigated for an underlying cause. Provided that there is clinical resolution of acute pregnancy-related hypertension, investigations are usually postponed until at least 3 months following delivery.
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7789288
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Optimal treatment of erectile failure in patients with diabetes.
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Erectile failure, although a common problem in male diabetic patients, is one of the most neglected complications of diabetes. The availability of drugs like alprostadil (prostaglandin E1; PGE1) and papaverine for intracavernosal injection and the development of vacuum tumescence devices, while making therapy simple, have also reduced the necessity for specialised investigations. In the past 10 years, alprostadil has been shown to be the safest and the most effective of the intracavernosal self-injection treatments of erectile dysfunction. Vacuum tumescence devices are an acceptable noninvasive alternative in those who fail to achieve a satisfactory response to self-injection. Surgical techniques are being improved every day, and revascularisation procedures and prosthetic implants are available to couples in specialised centres. At present, systemic drug therapy has been largely ineffective for treatment in diabetic patients but progress is being made in this field. Whatever the option, involvement of the partner in decision making is of major importance for the treatment to be successful, and psychosexual counselling is a useful adjunct to medical or surgical therapy.
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7789287
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Controversies in selection of epoetin dosages. Issues and answers.
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Epoetin (recombinant human erythropoietin) is now a widely available though expensive treatment for the anaemia of chronic renal failure, and is effective in more than 95% of patients. Complications of epoetin in this context include hypertension in a third of cases, including hypertensive encephalopathy in a few, and thrombosis of shunts or vascular access devices. Fears that epoetin would cause progression of renal failure have not generally been confirmed, but hyperkalaemia may be a problem in the initial phase of treatment. Epoetin is up to twice as effective when administered subcutaneously rather than intravenously. Responding patients will normally do so within 3 months of starting epoetin. Failures to respond are usually due to iron deficiency or intercurrent disease. Other diseases associated with anaemia and an inappropriately low serum epoetin level include prematurity, the anaemia of cancer and rheumatoid arthritis. The baseline serum endogenous erythropoietin may provide a guide to response in some of these cases. Some encouraging results are being published. Situations where the serum erythropoietin levels are normal or elevated where epoetin has been employed include boosting of haematocrit presurgery as an adjunct to autologous blood donation, treatment of anaemic patients with myelodysplastic syndromes, and improvement of athletic performances.
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7789285
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Drug therapies for sexually transmitted diseases. Clinical and economic considerations.
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Sexually transmitted diseases (STDs) are common, and result in immense social and economic costs. In some countries they have a major demographic impact. Because many STDs facilitate the transmission of HIV, the consequences of STDs are further increasing. At the same time, this association between STDs and HIV provides one of the ways in which drug therapy should be very cost effective. The perspective taken in this article is a societal one, and broader issues than those directly related to drug costs and benefits are discussed. However, it is the availability of drugs that has the potential to most quickly and most reliably make a major difference to overall health sector and societal costs as they relate to STDs. For those STDs for which curative therapy is available (particularly Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum, and Trichomonas vaginalis) there have been large decreases in prevalence in many parts of the world. In contrast, those STDs for which curative therapy is not available (particularly HIV, genital herpes and genital human papillomavirus infection) have had stable or increasing prevalence. For these latter infections, each new case increases the overall prevalence. Numerous features of STDs make clinical and economic evaluation difficult. These include the sensitive nature of the topic, the changing epidemiology and drug susceptibility of individual STDs, the fact that a large proportion of those infected are asymptomatic, difficulties in making specific diagnoses, the fact that often consequences are recognised late, sexual re-exposure and reinfection, and inadequate data on which to do clinical and economic evaluations. Furthermore, risk of acquiring an STD roughly correlates inversely with socioeconomic status, and countries or places with the highest rates of STDs may have the least ability to deal effectively with their diagnosis and management. Most of the direct and indirect costs are incurred by women, since they experience the vast majority of the complications of STDs. Many of these only become apparent years later, which makes it very hard to attribute costs and benefits to a specific episode of infection, and to its treatment. The late and indirect costs, plus the costs of prevention, are hard to quantify. That the major burden of STDs is in adolescents and young adults, socioeconomically disadvantaged groups and women has important implications, including for pharmacoeconomic studies.(ABSTRACT TRUNCATED AT 400 WORDS)
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7789283
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Specification of anterior-posterior differences within the AB lineage in the C. elegans embryo: a polarising induction.
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In a C. elegans embryo the third cleavages of descendants of the anterior blastomere AB of the 2-cell stage create pairs of blastomeres that develop differently. By laser ablation experiments we show that the fates of all the posterior daughters of this division depend on an induction occurring three cleavages before these blastomeres are born. The time of induction precludes a direct effect on cell fate. Alternatively, we suggest that the induction creates a heritable cell polarity which is propagated through several divisions. We suggest a model to demonstrate how a signal could be propagated through several rounds of cell division. An important implication of our observations is that this early induction acts to specify blastomere identity, not tissue type. A detailed lineage analysis revealed that altering the inductive signal alters complex lineage patterns as a whole. The induction described here, together with two inductions described previously can be used to illustrate how the anterior portion of the C. elegans embryo can be successively subdivided into blastomeres with unique developmental potential.
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7789282
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Notch1 is required for the coordinate segmentation of somites.
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Members of the Notch family of transmembrane receptors mediate a number of developmental decisions in invertebrates. In order to study Notch function in a vertebrate organism, we have mutated the Notch1 gene of the mouse. Notch1 gene function is required for embryonic survival in the second half of gestation. In the first half of gestation, we have found no effect of the mutation on the normal programs of neurogenesis, myogenesis or apoptosis. We conclude that Notch1 function is not essential for these processes, at least in early postimplantation development. However, we have found that somitogenesis is delayed and disorganized in Notch1 mutant embryos. We propose that Notch1 normally coordinates the process of somitogenesis, and we provide a model of how this might occur.
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7789281
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Arabidopsis gynoecium structure in the wild and in ettin mutants.
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The gynoecium is the female reproductive structure of flowering plants. Here we present a description of the Arabidopsis thaliana gynoecium at anthesis. The cylindrical organ can be broken down into three longitudinal regions arranged in an apical-basal order: stigma, style, and ovary. Each region can be distinguished histologically and morphologically. The transmitting (pollination) tract is axially positioned along the center of the gynoecium and spans stigma, style and ovary. Histochemistry, scanning electron microscopy and a style-specific reporter gene are used to compare the wild-type pattern of gynoecium cell types and regions, with patterns formed in gynoecia of individuals homozygous for a series of allelic mutations at the ETTIN locus. ettin gynoecia show morphological and histological alterations that appear to result from the merging of apical and basal regions and the development of abaxial into adaxial tissues. These developmental abnormalities result in a reduction of the ovary region, an expansion of the stylar and stigmatic regions, and the abaxial (outward) proliferation of transmitting tract tissue. The alterations in the mutants can be interpreted as resulting from misspecifications of position along the longitudinal and transverse axes during gynoecium development. The results suggest that early patterning events underlie wild-type gynoecium development, and that ETT functions during this early programming.
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7789280
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Sulphated proteoglycan is required for collecting duct growth and branching but not nephron formation during kidney development.
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Kidney epithelia have separate origins; collecting ducts develop by ureteric bud growth and arborisation, nephrons by induced mesenchyme-epithelium transition. Both express sulphated glycosaminoglycans (GAGs) which are strikingly upregulated during nephron differentiation. However, sodium chlorate, an inhibitor of GAG sulphation, and the GAG-degrading enzymes heparitinase plus chondroitinase, did not prevent nephron development. In contrast, ureteric bud growth and branching were reversibly inhibited by the above reagents, the inhibition correlating quantitatively with sulphated GAG deprivation caused by a range of chlorate concentrations. Growth and branching could be independently restored during GAG deprivation by hepatocyte growth factor and phorbol-12-myristate acetate (PMA) respectively. Together these signalling effectors stimulated both branch initiation and growth. Thus growth and morphogenesis of ureteric bud involve distinct signalling pathways both regulated by GAGs.
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7789279
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Autonomous and non-autonomous differentiation of ectoderm in different sea urchin species.
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During early embryogenesis, the highly regulative sea urchin embryo relies extensively on cell-cell interactions for cellular specification. Here, the role of cellular interactions in the temporal and spatial expression of markers for oral and aboral ectoderm in Strongylocentrotus purpuratus and Lytechinus pictus was investigated. When pairs of mesomeres or animal caps, which are fated to give rise to ectoderm, were isolated and cultured they developed into ciliated embryoids that were morphologically polarized. In animal explants from S. purpuratus, the aboral ectoderm-specific Spec1 gene was activated at the same time as in control embryos and at relatively high levels. The Spec1 protein was restricted to the squamous epithelial cells in the embryoids suggesting that an oral-aboral axis formed and aboral ectoderm differentiation occurred correctly. However, the Ecto V protein, a marker for oral ectoderm differentiation, was detected throughout the embryoid and no stomodeum or ciliary band formed. These results indicated that animal explants from S. purpuratus were autonomous in their ability to form an oral-aboral axis and to differentiate aboral ectoderm, but other aspects of ectoderm differentiation require interaction with vegetal blastomeres. In contrast to S. purpuratus, aboral ectoderm-specific genes were not expressed in animal explants from L. pictus even though the resulting embryoids were morphologically very similar to those of S. purpuratus. Recombination of the explants with vegetal blastomeres or exposure to the vegetalizing agent LiCl restored activity of aboral ectoderm-specific genes, suggesting the requirement of a vegetal induction for differentiation of aboral ectoderm cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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7789278
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Tissue non-specific alkaline phosphatase is expressed in both embryonic and extraembryonic lineages during mouse embryogenesis but is not required for migration of primordial germ cells.
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Mouse primordial germ cells express tissue non-specific alkaline phosphatase (TNAP) during development, but the widespread expression of another alkaline phosphatase gene in the early embryo limits the potential use of this marker to trace germ cells. To attempt to identify germ cells at all stages during embryonic development and to understand the role of TNAP in germ cell ontogeny, mice carrying a beta geo (lacZ/neor) disrupted allele of the TNAP gene were generated by homologous recombination in embryonic stem cells. Using beta-galactosidase activity, the embryonic pattern of TNAP expression was examined from the blastocyst stage to embryonic day 14. Results indicate that primordial germ cell progenitors do not express TNAP prior to gastrulation although at earlier times TNAP expression is found in an extraembryonic lineage destined to form the chorion. In homozygous mutants, primordial germ cells appear unaffected indicating that TNAP is not essential for their development or migration.
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7789277
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Role of MAP kinase in mesoderm induction and axial patterning during Xenopus development.
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We have examined the role of MAP kinase during mesoderm induction and axial patterning in Xenopus embryos. MAP Kinase Phosphatase (MKP-1) was used to inactivate endogenous MAP kinase and was found to prevent the induction of early and late mesodermal markers by both FGF and activin. In whole embryos, MKP-1 was found to disrupt posterior axial patterning, generating a phenotype similar to that obtained with a dominant inhibitory FGF receptor. Overexpression of either constitutively active MAP kinase or constitutively active MAP kinase (MEK) was sufficient to induce Xbra expression, while only constitutively active MEK was able to significantly induce expression of muscle actin. When MAP kinase phosphorylation was used as a sensitive marker of FGF receptor activity in vivo, this activity was found to persist at a low and relatively uniform level throughout blastula stage embryos. The finding that a low level of MAP kinase phosphorylation exists in unstimulated animal caps and is absent in caps overexpressing a dominant inhibitory FGF receptor provides a basis for our previous observation that overexpression of this receptor inhibits activin induction. These results indicate that FGF-dependent MAP kinase activity plays a critical role in establishing the responsiveness of embryonic tissues to mesoderm inducers.
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7789276
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Linkage of cardiac left-right asymmetry and dorsal-anterior development in Xenopus.
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The left-right body axis is defined relative to the dorsal-ventral and anterior-posterior body axes. Since left-right asymmetries are not randomly oriented with respect to dorsal-ventral and anterior-posterior spatial patterns, it is possible that a common mechanism determines all three axes in a coordinate manner. Two approaches were undertaken to determine whether alteration in dorsal-anterior development perturbs the left-right orientation of heart looping. Treatments known to decrease dorsal-anterior development in Xenopus laevis, UV irradiation during the first cell cycle or Xwnt-8 DNA injections into dorsal blastomeres, caused an increase in cardiac left-right reversals. The frequency of left-right reversal was correlated with the severity of dorsal-anterior perturbation and with the extent of anterior notochord regression. Injection of Xwnt-8 DNA into dorsal midline cells resulted in decreased dorsal-anterior development and a correlated increase in cardiac left-right reversals. In contrast, injection of Xwnt-8 DNA into cardiac progenitor blastomeres did not result in left-right reversals, and dorsal-anterior development and notochord formation were normal. Disrupting development of dorsal-anterior cells, including cells that give rise to the Organizer region and the notochord, results in the randomization of cardiac left-right asymmetry. These results suggest dorsal-anterior development and the regulation of left-right orientation are linked.
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7789275
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The Drosophila E74 gene is required for metamorphosis and plays a role in the polytene chromosome puffing response to ecdysone.
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The steroid hormone ecdysone initiates Drosophila metamorphosis by reprogramming gene expression during late larval and prepupal development. The ecdysone-inducible gene E74, a member of the ets proto-oncogene family, has been proposed to play a key role in this process. E74 is encoded within the 74EF early puff and consists of two overlapping transcription units, E74A and E74B. To assess the function(s) of E74 during metamorphosis, we have isolated and characterized recessive loss-of-function mutations specific to each transcription unit. We find that mutations in E74A and E74B are predominantly lethal during prepupal and pupal development, consistent with a critical role for their gene products in metamorphosis. Phenotypic analysis reveals that E74 function is required for both pupariation and pupation, and for the metamorphosis of both larval and imaginal tissues. E74B mutants are defective in puparium formation and head eversion and die as prepupae or cryptocephalic pupae, while E74A mutants pupariate normally and die either as prepupae or pharate adults. We have also investigated the effects of the E74 mutations on gene expression by examining the puffing pattern of the salivary gland polytene chromosomes in newly formed mutant prepupae. Most puffs are only modestly affected by the E74B mutation, whereas a subset of late puffs are sub-maximally induced in E74A mutant prepupae. These observations are consistent with Ashburner's proposal that early puff proteins induce the formation of late puffs, and define E74A as a regulator of late puff activity. They also demonstrate that E74 plays a wide role in reshaping the insect during metamorphosis, affecting tissues other than the salivary gland in which it was originally identified.
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7789273
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The role of Pax-6 in eye and nasal development.
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Small eye (Sey) mice homozygous for mutations in the Pax-6 gene have no lenses and no nasal cavities. We have examined the ontogeny of eye and nasal defects in Sey/Sey embryos and have related the defects seen to the pattern of Pax-6 mRNA expression in the mouse during normal eye and nasal development. There are two principal components of the early eye, the neural ectoderm of the optic vesicle, which forms the retina, and the overlying surface ectoderm, which forms the lens and cornea. By studying these interacting tissues in normal and Sey/Sey embryos, we have identified processes for which Pax-6 is important and can thus suggest possible roles for the Pax-6 gene. Pax-6 is essential for the formation of lens placodes from surface ectoderm. In normal development, early Pax-6 mRNA expression in a broad domain of surface ectoderm is downregulated, but expression is specifically maintained in the developing lens placode. Moreover, other Pax-6-expressing tissues are frequently those that have can transdifferentiate into lens. Thus, phenotype and expression together suggest a role for Pax-6 in lens determination. At least some functions of Pax-6 can be separated from the influence of other tissues. Early Sey/Sey optic vesicles are abnormally broad and fail to constrict proximally. These defects occur prior to the time of lens placode formation and probably reflect a requirement for Pax-6 in neural ectoderm. In surface ectoderm domains, where Pax-6 expression is known to be independent of the presence of an optic vesicle, Pax-6 function is required for the maintenance of its own transcription. The mutual dependency of lens and optic vesicle development can also be studied using the Small eye mutation. Using region-specific markers we find that, in the morphologically abnormal Sey/Sey optic vesicles, aspects of normal proximo-distal specification nevertheless persist, despite the complete absence of lens. Like the lens, the nasal cavities develop from ectodermal placodes that normally express Pax-6 mRNA, fail to form in Sey/Sey mice and show Pax-6-dependent Pax-6 mRNA regulation. Analysis of patterns of programmed cell death and absence of nasal region expression from an Msx-1 transgene in Sey/Sey embryos suggest a requirement for Pax-6 in the transition from presumptive nasal ectoderm to placode, and that Msx-1, or genes regulating it, are possible targets for Pax-6.
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7789274
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Axonal guidance in the chicken retina.
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During retina development, ganglion cells extend their axons exclusively into the innermost tissue layer, but not into outer retina layers. In order to elucidate guiding mechanisms for axons, tissue strips of embryonic chicken retinae were explanted onto retinal cryosections (cryoculture). Ganglion cell axons originating from the explant grew preferentially on the innermost retina layer of cryosections, whereas outer tissue layers were avoided, very much as in vivo. Stereotropism, interaction with laminin of the basal lamina and axonal fasciculation did not significantly affect oriented axonal outgrowth, so that stereotropism as a guidance mechanism could be excluded. Ganglion cell axons were not directed by physical barriers, e.g. microstructured silicon oxide chips. Similarly, UV induced protein inactivation revealed that laminin present in the inner retina did not provide a guidance cue. Even in the absence of ganglion cell axons in retinal cryosections due to prior optic nerve transection in ovo, the growth preference for the innermost retina layer was maintained in cryocultures. However, oriented elongation of axons along the innermost retina layer was lost when radial glial endfeet were selectively eliminated in retinal cryosections. In addition, glial endfeet provided an excellent growth substratum when pure preparations of endfeet were employed in explant cultures. The preference for glial endfeet positioned at the inner retina surface was accompanied by the avoidance of outer retina layers, most likely because of inhibitory components in this region. This assumption is corroborated by the finding that addition of exogenous growth-promoting laminin to cryosections did not abolish the inhibition. Laminin on glass surfaces provided an excellent substratum. Axonal outgrowth was also seriously hampered on specifically purified cells of the outer retina. Most notable, however, in cryocultures aberrant innervation of outer retina layers could be induced by prior heat or protease treatment of cryosections, which pointed to proteins as potential inhibitory components. In summary the data substantiate the hypothesis that within the retina, ganglion cell axons are guided by a dual mechanism based on a permissive and an inhibitory zone. Radial glia is likely to be instructive in this process.
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7789272
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Terminal diversification of the myocyte lineage generates Purkinje fibers of the cardiac conduction system.
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The rhythmic contraction of the vertebrate heart is dependent on organized propagation of electrical excitation through the cardiac conduction system. Because both muscle- and neuron-specific genes are co-expressed in cells forming myocardial conduction tissues, two origins, myogenic and neural, have been suggested for this specialized tissue. Using replication-defective retroviruses, encoding recombinant beta-galactosidase (beta-gal), we have analyzed cell lineage for Purkinje fibers (i.e., the peripheral elements of the conduction system) in the chick heart. Functioning myocyte progenitors were virally tagged at embryonic day 3 of incubation (E3). Clonal beta-gal+ populations of cells, derived from myocytes infected at E3 were examined at 14 (E14) and 18 (E18) days of embryonic incubation. Here, we report that a subset of clonally related myocytes differentiates into conductile Purkinje fibers, invariably in close spatial association with forming coronary arterial blood vessels. These beta-gal+ myogenic clones, containing both working myocytes and Purkinje fibers, did not incorporate cells contributing to tissues of the central conduction system (e.g. atrioventricular ring and bundles). In quantitative analyses, we found that whereas the number of beta-gal+ myocyte nuclei per clone more than doubled between E14 and E18, the number of beta-gal+ Purkinje fiber nuclei remained constant.(ABSTRACT TRUNCATED AT 250 WORDS)
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7789271
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The Drosophila E74 gene is required for the proper stage- and tissue-specific transcription of ecdysone-regulated genes at the onset of metamorphosis.
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The steroid hormone ecdysone directly induces a small set of early genes, visible as puffs in the larval salivary gland polytene chromosomes, as it signals the onset of Drosophila metamorphorsis. The products of these genes appear to function as regulators that both repress their own expression and induce a large set of secondary-response late genes. We have identified recessive loss-of-function mutations in the early gene E74, a member of the ets protooncogene family that encodes two related DNA-binding proteins, E74A and E74B. These mutations cause defects in pupariation and pupation, and result in lethality during metamorphosis. Here we extend our phenotypic characterization of the E74A and E74B mutant alleles to the molecular level by examining their effects on the transcription of over 30 ecdysone-regulated genes. We show that the transcription of most ecdysone primary-response genes during late larval and prepupal development is unaffected by the E74 mutations. Rather, we find that E74 is necessary for the appropriate regulation of many ecdysone secondary-response genes. E74B is required for the maximal induction of glue genes in mid third instar larval salivary glands, while E74A is required in early prepupae for the proper timing and maximal induction of a subset of late genes. E74 activity is also necessary for the correct regulation of genes expressed predominantly in the fat body, epidermis or imaginal discs. These observations confirm that E74 plays a critical role in regulating transcription during the early stages of Drosophila metamorphosis. In addition, the widespread effects of the E74 mutations on transcription indicate that E74 functions in regulatory hierarchies not only in the larval salivary gland, but throughout the entire organism.
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7789270
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Multiple roles for FGF-3 during cranial neural development in the chicken.
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FGF-3 has been implicated in the development of the hindbrain and otocyst in vertebrate embryos. Since the chicken embryo offers a favourable system in which to study the development of these structures, we have isolated and characterised cDNAs for chicken Fgf-3 and determined its pattern of expression in chick embryos from stage 3 (primitive streak) to stage 25 (early organogenesis). Within the developing cranial neural tube, Fgf-3 exhibits dynamic spatial and temporal expression. During extension of the head process, RNA is detected in the midline of the developing neural plate. In neurulating embryos, transcripts are observed initially in rhombomeres 4 and 5 of the hindbrain and later, in rhombomere 6. During hindbrain development, expression is lost from these rhombomeres, but becomes restricted to rhombomere boundaries, providing an intracellular marker which distinguishes a population of cells within boundary regions. Fgf-3 expression is elevated in ventral and medial boundary regions and is greatly reduced in dorsal parts. Studies of regenerating rhombomere boundaries show that Fgf-3 expression is induced in reforming boundaries when even-numbered rhombomere tissue is grafted next to odd, but not when like is juxtaposed to like. Fgf-3 disappears from boundary regions just prior to the loss of the morphological boundaries suggesting a boundary-associated function. Other sites of expression have also been identified. At early stages of development Fgf-3 is expressed in the epiblast and mesendoderm of the primitive streak, in mesoderm lateral to the streak and in Hensen's node. In older embryos transcripts are detected in the endoderm of the pharyngeal pouches, the ectoderm of the second and third pharyngeal arches and the stomodeum. Expression was also detected in the segmental plate and in the posterior half of the three most-recently generated somites.
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7789269
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Ectoderm induces muscle-specific gene expression in Drosophila embryos.
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We have inhibited normal cell-cell interactions between mesoderm and ectoderm in wild-type Drosophila embryos, and have assayed the consequences on muscle development. Although most cells in gastrulation-arrested embryos do not differentiate, they express latent germ layer-specific genes appropriate for their position. Mesoderm cells require proximity to ectoderm to express several muscle-specific genes. We show that ventral ectoderm induces mesoderm cells to express nautilus (a MyoD homologue) and to differentiate somatic myofibers, whereas dorsal ectoderm induces mesoderm cells to express visceral and cardiac muscle-specific genes. Our findings suggest that muscle determination in Drosophila is regulated by induction between germ layers during gastrulation.
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7789268
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Hoxa 11 structure, extensive antisense transcription, and function in male and female fertility.
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Hoxa 11 is a murine Abdominal-B-type homeobox gene. The structure of this gene is presented, including genomic and cDNA sequence. The cDNA includes the complete open reading frame and based on primer extension results is near full length. Surprisingly, the antisense strand of Hoxa 11 was found to be transcribed. Moreover, these antisense transcripts were processed and polyadenylated. The developmental expression patterns for both sense and antisense transcripts were examined using serial section and whole-mount in situ hybridizations. Hoxa 11 transcription patterns were defined in the limbs, kidney and stromal cells surrounding the Mullerian and Wolffian ducts. Of particular interest, in the developing limbs, the sense and antisense transcripts showed complementary expression patterns, with antisense RNAs increasing in abundance in regions where sense RNAs were diminishing in abundance. Furthermore, targeted mutation of Hoxa 11 is shown to result in both male and female sterility. The female mutants produce normal ova, which develop properly post-fertilization when transferred to wild-type surrogate mothers. The Hoxa 11 homozygous mutants are shown to provide a defective uterine environment. The mutant males exhibited a malformation of the vas deferens that resembles a partial homeotic transformation to an epididymis. In addition, the mutant testes fail to descend properly into the scrotum and, likely as a result, spermatogenesis is perturbed.
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7789267
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Cell fate control in the Drosophila retina by the orphan receptor seven-up: its role in the decisions mediated by the ras signaling pathway.
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Drosophila seven-up is an orphan receptor of the steroid receptor family that is required to specify photoreceptor neuron subtypes in the developing compound eye. Expression of seven-up is confined to four of the eight photoreceptor precursors, R3/R4/R1/R6. We show that misexpression of seven-up in any of the other cell types within the developing ommatidium interferes with their differentiation. Each cell type responds differently to seven-up misexpression. For example, ectopic expression in the non-neuronal cone cells using the sevenless promoter/enhancer (sev-svp) causes the cone cells to take on a neuronal identity. Ectopic expression of seven-up in R2/R5 using the rough enhancer (ro-svp) causes these neurons to lose aspects of their photoreceptor subtype identity while remaining neuronal. Each cell type appears to have a different developmental time window that is sensitive to misexpressed seven-up. The temporal order of responsiveness of each cell type to misexpressed seven-up is similar but not identical to the order of neuronal differentiation. This suggests that there are processes of specification that are distinct from the specification to become a photoreceptor neuron. We have identified members of the ras signaling pathway as suppressors of the cone cell to R7 neuron transformation caused by sev-svp. Suppression of the sev-svp phenotype can be achieved by decreasing the gene-dosage of any of the members of the ras-pathway. This suggests that the function of seven-up in the cone cells requires ras signaling. However, a decrease in ras signaling results in enhancement of the phenotype caused by the ro-svp transgene. We discuss the relationship between decisions controlled by seven-up and those controlled by ras signaling.
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7789266
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Patterning of the mesoderm in Xenopus: dose-dependent and synergistic effects of Brachyury and Pintallavis.
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Widespread expression of the DNA-binding protein Brachyury in Xenopus animal caps causes ectopic mesoderm formation. In this paper, we first show that two types of mesoderm are induced by different concentrations of Brachyury. Animal pole explants from embryos injected with low doses of Xbra RNA differentiate into vesicles containing mesothelial smooth muscle and mesenchyme. At higher concentrations somitic muscle is formed. The transition from smooth muscle formation to that of somitic muscle occurs over a two-fold increase in Brachyury concentration. Brachyury is required for differentiation of notochord in mouse and fish embryos, but even the highest concentrations of Brachyury do not induce this tissue in Xenopus animal caps. Co-expression of Brachyury with the secreted glycoprotein noggin does cause notochord formation, but it is difficult to understand the molecular basis of this phenomenon without knowing more about the noggin signal transduction pathway. To overcome this difficulty, we have now tested mesoderm-specific transcription factors for the ability to synergize with Brachyury. We find that co-expression of Pintallavis, but not goosecoid, with Brachyury causes formation of dorsal mesoderm, including notochord. Furthermore, the effect of Pintallavis, like that of Brachyury, is dose-dependent: a two-fold increase in Pintallavis RNA causes a transition from ventral mesoderm formation to that of muscle, and a further two-fold increase induces notochord and neural tissue. These results suggest that Pintallavis cooperates with Brachyury to pattern the mesoderm in Xenopus.
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7789265
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Muscle sensory neurons require neurotrophin-3 from peripheral tissues during the period of normal cell death.
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To determine if muscle sensory neurons require neurotrophin-3 (NT3) during the period of normal cell death, we used an NT3-specific antiserum to deplete NT3 from peripheral tissues during this period in chick embryos. DiI staining of dorsal roots indicated that limb injections of anti-NT3 reduced the spinal projection of muscle spindle afferents. In contrast, injection of the antiserum into the spinal cord had no demonstrable effect, indicating that the reduced projection following limb injection was due to peripheral blockade of NT3 signaling. Counts of neurons retrogradely labeled from muscle and cutaneous nerves showed that peripheral blockade of NT3 selectively reduced the survival of muscle sensory neurons without affecting the survival of cutaneous sensory neurons or motoneurons. In situ hybridization with trkC probes indicated that, during the period of cell death, most large diameter muscle sensory neurons express trkC transcripts, whereas few cutaneous neurons express this receptor for NT3. We conclude that large diameter muscle afferents, including spindle afferents, require NT3 from peripheral tissues to survive the normal period of sensory neuron death in vivo.
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7789264
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CSF-1 and mouse preimplantation development in vitro.
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The effects of macrophage colony stimulating factor on the development of the zygote to the blastocyst stage of an outbred strain of mouse have been studied in KSOM, an improved medium that supports a high rate of in vitro development. Macrophage colony stimulating factor accelerates the formation of the blastocyst cavity by day 4 (96 hours post-hCG). It also increases overall embryonic cell number through a differential increase in the number of trophoblast cells, with no significant effect on the number of inner cell mass cells. By day 5 of culture (120 hours post-hCG), colony stimulating factor-treated embryos have about 20 more trophoblast cells than control embryos, an increase of about 30 percent of the total number of cells in a control blastocyst. The maximum response of embryos was obtained at a concentration around 540 U ml-1 colony stimulating factor (identical to 918 Stanley units ml-1), and the cytokine can produce the same effects even if it is present in the medium for only part of the culture period. This in vitro stimulation of preimplantation development with macrophage colony stimulating factor is compatible with continued normal fetal development in vivo.
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7789263
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Nonequivalent requirements for PS1 and PS2 integrin at cell attachments in Drosophila: genetic analysis of the alpha PS1 integrin subunit.
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We report on the generation and phenotype of mutant alleles of multiple edematous wings (mew), the gene encoding the alpha PS1 subunit of the PS1 integrin of Drosophila. None of the six alleles examined makes detectable protein, and one allele results from a chromosome break near the middle of the translated sequence, so we are confident that we have described the null phenotype. In contrast to if (alpha PS2) and mys (beta PS) mutants, most mutant mew embryos hatch, to die as larvae. Mutant mew embryos display abnormal gut morphogenesis but, unlike mys or if embryos, there is no evidence of defects in the somatic muscles. Thus, the complementary distributions of PS1 (alpha PS1 beta PS) and PS2 (alpha PS2 beta PS) integrin on tendon cells and muscle, respectively, do not reflect equivalent requirements at the myotendinous junction. Dorsal herniation, characteristic of the mys lethal phenotype, is not observed in mew or in mew if embryos. Clonal analysis experiments indicate that eye morphogenesis is disrupted in mew clones, but if clones in the eye are relatively normal in morphology. Adult wings display blisters around large dorsal but not ventral mew clones. In contrast to dorsal mys clones, small mew patches do not necessarily display morphogenetic abnormalities. Thus, another integrin in addition to PS1 appears to function on the dorsal wing surface.
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7789262
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Neurotrophins affect the pattern of DRG neurite growth in a bioassay that presents a choice of CNS and PNS substrates.
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Neurons can be categorized in terms of where their axons project: within the central nervous system, within the peripheral nervous system, or through both central and peripheral environments. Examples of these categories are cerebellar neurons, sympathetic neurons, and dorsal root ganglion (DRG) neurons, respectively. When explants containing one type of neuron were placed between cryosections of neonatal or adult sciatic nerve and neonatal spinal cord, the neurites exhibited a strong preference for the substrates that they would normally encounter in vivo: cerebellar neurites generally extended only on spinal cord, sympathetic neurites on sciatic nerve, and DRG neurites on both. Neurite growth from DRG neurons has been shown to be stimulated by neurotrophins. To determine whether neurotrophins might also affect the substrate preferences of neurites, DRG were placed between cryosections of neonatal spinal cord and adult sciatic nerve and cultured for 36 to 48 hours in the presence of various neurotrophins. While DRG cultured in NGF-containing media exhibited neurite growth over both spinal cord and sciatic nerve substrates, in the absence of neurotrophins DRG neurites were found almost exclusively on the CNS cryosection. To determine whether these neurotrophin-dependent neurite patterns resulted from the selective survival of subpopulations of DRG neurons with distinct neurite growth characteristics, a type of rescue experiment was performed: DRG cultured in neurotrophin-free medium were fed with NGF-containing medium after 36 hours in vitro and neurite growth examined 24 hours later; most DRG exhibited extensive neurite growth on both peripheral and central nervous system substrates.(ABSTRACT TRUNCATED AT 250 WORDS)
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7789261
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Targeted disruption of the low-affinity leukemia inhibitory factor receptor gene causes placental, skeletal, neural and metabolic defects and results in perinatal death.
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The low-affinity receptor for leukemia inhibitory factor (LIFR) interacts with gp130 to induce an intracellular signal cascade. The LIFR-gp130 heterodimer is implicated in the function of diverse systems. Normal placentation is disrupted in LIFR mutant animals, which leads to poor intrauterine nutrition but allows fetuses to continue to term. Fetal bone volume is reduced greater than three-fold and the number of osteoclasts is increased six-fold, resulting in severe osteopenia of perinatal bone. Astrocyte numbers are reduced in the spinal cord and brain stem. Late gestation fetal livers contain relatively high stores of glycogen, indicating a metabolic disorder. Hematologic and primordial germ cell compartments appear normal. Pleiotropic defects in the mutant animals preclude survival beyond the day of birth.
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7789260
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Wingless induces transdetermination in developing Drosophila imaginal discs.
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Drosophila imaginal discs, the precursors of the adult fly appendages, have been the subject of intensive developmental studies, particularly on cell determination. Cultured disc fragments are recognized not only for the ability to maintain their determined state through extra cell divisions but also for the ability to transdetermine, or switch to the determined state of a different disc. An understanding of transdetermination at a molecular level will provide further insight into the requirements for maintaining cell determination. We find that ectopic expression of the Drosophila gene wingless induces transdetermination of foreleg imaginal disc cells to wing cells. This transdetermination occurs in foreleg discs of developing larvae without disc fragmentation. The in situ-transdetermining cells localize to the dorsal region of the foreleg disc. This wingless-induced transdetermination event is remarkably similar to the leg-to-wing switch that occurs after leg disc culture. Thus we have identified a new approach to a molecular dissection of transdetermination.
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7789259
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The C. elegans neuronally expressed homeobox gene ceh-10 is closely related to genes expressed in the vertebrate eye.
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We describe the homeobox gene ceh-10 from the nematode Caenorhabditis elegans. The homeodomain of ceh-10 is closely related to the homeodomains of two genes recently cloned from the vertebrate retina, Chx10 from mice and Vsx-1 from goldfish. We show that the sequence conservation extends well beyond the homeodomain and includes a region (named the CVC domain) of roughly 60 amino acids immediately C-terminal to the homeodomain. As assayed in transgenic worms, the promoter region of ceh-10 directs expression of a lacZ reporter gene to a small number of neurons. We draw a parallel between the bipolar cells of the inner nuclear layer of the vertebrate retina, which express Chx10 and Vsx-1, and an interneuron in C. elegans called AIY, which expresses ceh-10. AIY receives synaptic input from a sensory cell, just as do bipolar cells of the vertebrate retina. In C. elegans, the sensory cell AFD is not known to be photosensitive but is known to be thermosensitive; moreover, a cell with similar position in the amphids of other nematodes has been suggested indeed to be photosensitive. Our results emphasize the highly conserved nature of sensory regulatory mechanisms and suggest one way in which photosensitive organelles might have originated in evolution.
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7789254
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Utilization of fine-needle aspiration biopsy in the diagnosis of metastatic tumors to the pancreas.
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There is relatively little information concerning the use of fine-needle aspiration biopsy (FNAB) to diagnose a mass in the pancreas that is secondary to metastatic tumor. This study reviews the incidence and types of neoplasms which metastasize to the pancreas and assesses the contribution FNAB can make in their diagnosis. Of 117 radiologically guided FNABs of the pancreas, 11% (n = 13) showed metastatic malignancy. Nine patients had a previous history of malignancy while four patients presented with a pancreatic mass and were subsequently found to have wide-spread malignant disease. The majority of metastatic lesions were epithelial (77%, n = 10). Patient outcomes were generally poor (mean survival 2.8 mo). Metastases to the pancreas occur from a variety of primary sites and should be considered in patients with a pancreatic mass and a history of prior malignancy. FNAB is useful in diagnosing these metastases and this is clinically important because of their poor prognosis.
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7789253
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Sialadenitis with crystalloid formation: a report of six cases diagnosed by fine-needle aspiration.
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Six cases of sialadenitis diagnosed by fine-needle aspiration contained large numbers of crystalloids. Light microscopy, ultrastructure, and chemical analysis suggest that the crystalloids represent crystallized salivary alpha-amylase. The inflammatory swelling may mimic benign and/or malignant neoplasms of the salivary glands. Drainage and/or antibiotic therapy may allow surgery to be avoided in these patients.
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7789252
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Calcifying epithelial odontogenic tumor (Pindborg's tumor) on fine-needle aspiration biopsy smears: a case report.
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A 44-yr-old woman with a long-standing history of painful mandibular swelling was hospitalized for the diagnostic evaluation of an osteolytic mandibular lesion in the premolar-canine area. Fine-needle aspiration biopsy (FNAB) was performed and cytologic smears were characterized by clusters, sheets, and rare isolated pleomorphic cells of the squamoid type, blocks of amorphous material encircled by fibroblasts, and occasional calcifications. A cytological diagnosis of Pindborg's tumor was made, which was confirmed by histopathological examination. Evaluation of DNA ploidy by semiautomated image cytometry produced an aneuploid histogram. The patient is free of residual neoplasm at a 12-mo post-operative interval. The cytological differential diagnosis of this rare odontogenic neoplasm is discussed briefly.
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7789251
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Calcium oxalate crystals in benign breast cyst fluid.
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We have recently observed a strongly birefringent material of varying shapes and sizes in a benign breast cyst fluid specimen from a 52-yr-old woman with suspicious mammographic microcalcifications. The finding of calcium oxalate crystals in the breast cyst fluid should be regarded as a recognition of a particular type of calcification, easily overlooked with the conventional light microscopy. To date, we are unaware of any cytologic reports of this type of calcification in the breast.
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7789250
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Glycogen-rich clear cell carcinoma of the breast: report of a case with fine-needle aspiration cytology and immunocytochemical and ultrastructural studies.
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Fine-needle aspiration cytology, immunocytochemistry, and electron microscopic findings are described in a case of glycogen-rich clear cell carcinoma of the breast. The aspirate contained many small and large papillary cell groups and numerous single tall columnar cells with apical cytoplasmic projections and mild to moderate degree of nuclear pleomorphism. Cytochemical localisation of glycogen and immunostaining on air-dried smears with CEA and actin monoclonal antibodies permitted the correct identification and differential diagnosis of the tumor. Electron microscopic examination of the resected specimen confirmed the diagnosis of glycogen-rich clear cell carcinoma. The differential diagnosis and potential diagnostic pitfalls are discussed, and recommendation are offered to prevent misdiagnosis.
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7789249
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Diagnosis of metastatic appendiceal adenocarcinoid in liver by fine-needle aspiration cytology.
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A 70-yr-old woman presented with symptoms clinically attributed to acute appendicitis. An adenocarcinoid tumor of the appendix was resected, followed by right hemicolectomy with negative lymph nodes. Seven years later, a fine-needle aspiration biopsy was performed on one of multiple hepatic nodules, revealing metastatic adenocarcinoid. The cytopathologic features of the metastatic tumor are described.
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7789248
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Nocardiosis diagnosed by lung FNA: a case report.
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A 63-yr-old woman with systemic lupus erythematosus (SLE) diagnosed 12 mo previously and treated with prednisolone and cyclophosphamide presented with recent fever and dyspnoea. The etiology of a 3 cm diameter centrally cystic coin lesion in the lower lobe of the left lung was obscure. Blood cultures and sputum examination had been non-contributory, and the diagnosis of Nocardia asteroides infection was initially made by cytologic examination of material obtained by lung fine-needle aspiration (FNA). It is notoriously difficult to detect this organism by conventional sputum examination or with histologic sections, and it has rarely been detected by lung FNA. If this organism is demonstrated, appropriate microbiologic cultures for confirmation and susceptibility testing should be instituted. Long-term antimicrobial therapy is needed. In this case, complete resolution of the lung lesion followed 5 mo of therapy.
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7789247
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Mycoses of the breast: diagnosis by fine-needle aspiration.
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Fungal infections of the breast are unusual and may clinically mimic carcinoma. When studied by fine-needle aspiration (FNA), such masses may yield necrosis, granulomatous inflammation, reactive histiocytes, and atypical epithelial cells. Cohesive groups of atypical epithelial cells featured nuclear enlargement and overlapping, as well as prominent nucleoli. The organisms may be widely scattered, so that careful evaluation was required for their identification. In concert with provocative clinical findings, these features may lead to an erroneous diagnosis of malignancy. We describe three women with mycotic masses of the breast initially studied by FNA. The first patient presented at age 31 with a large, firm breast mass, chest wall extension, and radiographic evidence of vertebral bone involvement. FNA was requested to confirm the clinical diagnosis of advanced breast carcinoma. In addition to the atypia described above, the smears showed yeast forms indicative of blastomycosis surrounded by neutrophils. She remains well, following antifungal treatment. The second case of Blastomycosis was diagnosed by FNA of a breast mass in a 64-yr-old woman, who also responded to treatment. The third patient's preoperative needle aspiration showed granulomas, but no organisms were identified, even with special stains; silver stains of surgically excised tissue showed histoplasmosis.
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7789245
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Confocal microscopy of false-negative breast aspirates.
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Even when using a novel optimized FNA-21 for breast fine-needle aspiration biopsy, our series of 163 breast lesions with consecutive histology, including 110 carcinomas, contained eight cancer cases with a negative cytologic diagnosis. Two consisted exclusively of thick, undiagnosable epithelial fragments and were devoid of detached malignant cells on which the proper diagnosis could have been made. Optical sectioning of the original smears by the confocal microscope allowed us to reclaim from these epithelial fragments the diagnostic abnormal chromatin patterns, even in the air-dried smears. In the thin optical sections the cancerous tubular or cribriform growing pattern was visualized. The high spatial resolution of the confocal microscope can be further exploited with the application visualization system (AVS). The AVS three-dimensional reconstructions allow us to see the surface of these malignant cells in a detail approaching that of scanning electron microscopy. Furthermore, the internal aspects of the malignant nuclei can be visualized with these techniques.
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7789244
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Antigen expression of alveolar macrophages in smokers and patients with lung diseases.
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Alveolar macrophage function was studied immunocytochemically using three monoclonal antibodies--macrophage CD 68 KP 1 (M), protein CD 11C (P), and anti-elastin (EL)--and three polyclonal antibodies--lysozyme (LZ), alpha-1-antitrypsin (AAT), and alpha-1-antichymotrypsin (AACT). The material for study was smears obtained from bronchial washings from 15 healthy persons and 60 patients with respiratory infections or primary or secondary malignant lung infiltration. Eight of the healthy group and 40 of the patient group were smokers (SM). The percentage of cells obtained from the washings which were macrophages was also measured. The intensity of staining reactions for each of the six antigens was noted and in general more intense staining was noted in smokers than in non-smokers. More intense staining was observed in patients with pulmonary infections (group II PI) and metastatic pulmonary infiltrations (group IV MP Ca) than in controls (group IC), while patients with primary lung cancer (group III PP Ca) had highly reduced staining reactions. The number of macrophages was similarly increased in all groups in comparison with the IC group for non-smokers and in all groups except III PP Ca for smokers. It is concluded that smoking, pulmonary infections, and metastatic infiltration of the lung are associated with an increase in the number and activity of alveolar macrophages, while patients with primary lung cancer have an increase in the number of macrophages which are functionally incompetent.
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7789243
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Pulmonary lymphoma in cardiac transplant patients treated with OKT3 for rejection: diagnosis by fine-needle aspiration.
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At Hines VA Hospital, three out of 38 cardiac transplant patients, who were 9, 10, and 14 mo post-surgery and treated with immunosuppressive drugs, including OKT3 prophylaxis for acute rejection, developed a solitary pulmonary nodule. Fine-needle aspiration biopsy of the nodules in these three patients revealed a hypercellular, monotonous population of large lymphoid cells. These abnormal cells were isolated, with small aggregates occasionally seen. The nuclear membranes were irregular, the chromatin was finely granular, nucleoli were prominent, and mitotic figures were frequently noted. The cells were immunoreactive to leukocyte common antigen and B-lymphocyte. Lambda light chain immunoglobulin was positive in one case, kappa in the second case, and neither light chains in the third patient. By electron microscopy in one case, the cells were large immature lymphoid cells with immunoblastic features. Subsequent tissue studies, complemented by frozen section immunostaining, flow cytometry, and phenotyping, reaffirmed the diagnosis of malignant lymphoma. It appears that OKT3 therapy increases several fold the risk of lymphoma's developing in cardiac transplant patients. Preliminary published reports have also recommended close surveillance of patients receiving OKT3 for early indications of lymphoproliferative disorder and a reevaluation of the risk vs. benefit for the prophylatic use of OKT3.
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7789242
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Effusion cytology in Burkitt's lymphoma.
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The American form of Burkitt's lymphoma is a high-grade malignancy which usually involves the abdomen in children and young adults. There is only a limited literature which describes the cytologic features of Burkitt's lymphoma in serous effusions. We present three children with Burkitt's lymphoma initially diagnosed by effusion cytology. The first patient, an 11-yr-old boy, presented with bilateral pleural effusions, ascites, and abdominal masses and had diagnostic pleural fluid cytology without tissue confirmation (ultrastructural examination was performed on the effusion specimen). He died 7 months after the initial diagnosis. The second patient, a 9-yr-old boy, presented with ascites and abdominal masses and had diagnostic peritoneal fluid cytology with a subsequent confirmatory chest wall biopsy. The third patient, a 16-yr-old girl, presented with a 2-month history of irregular menses, a large pelvic mass, lymphadenopathy, and liver masses. Although an ovarian malignancy was clinically suspected, cytologic examination of her peritoneal fluid revealed Burkitt's lymphoma. Surgical exploration revealed involvement of her right ovary, cecum, and terminal ileum. The second and third patients are currently alive with no apparent disease following chemotherapy. In all three patients, effusion cytology revealed Burkitt's lymphoma, characterized by a uniform population of non-cohesive lymphoid cells with noncleaved nuclei, prominent multiple nucleoli, and scanty-to-moderate basophilic cytoplasm. Cytoplasmic and/or nuclear vacuoles were also seen, more prominent in Diff-Quik-stained, air-dried smears. These cases demonstrate the importance of recognizing the cytologic features of Burkitt's lymphoma, as serous fluid may be the initial diagnostic specimen.
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7789241
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Tuberculous lymphadenitis: extended cytomorphologic features.
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In tuberculous lymphadenitis, FNAC smears sometimes reveal only caseous necrosis without epithelioid cell granuloma. They pose a diagnostic problem, if AFB staining is negative. The diagnostic clue noticed in these cases was presence of multiple pink, homogenous structures with irregular shape and well-defined margins: "eosinophilic structures" (ES). The purpose of the present study is to find out the nature of ES and their role in the diagnosis of tuberculosis. Seventy FNAC smears from documented cases of tuberculous lymphadenitis were classified according to their cytomorphological features. The association and relation of ES with other morphological criteria was noted. Immunoperoxidase staining was performed to find out the reactivity of ES to tuberculous antigen. Its intensity of positivity was compared with epithelioid cell granuloma and degenerating granuloma. It was concluded that ES are degenerated granuloma and thus form an extended diagnostic criterion.
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7789240
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Diagnosis of lymphoma, leukemia, and metastatic tumor involvement of the cerebrospinal fluid by cytology and immunocytochemistry.
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Fifty-five cerebrospinal fluid (CSF) specimens from 42 patients with suspected meningeal tumor involvement were reviewed. Cytology in conjunction with immunocytochemistry identified 26 CSF specimens as malignant. There were fifteen cases of lymphoma, four cases of leukemia, two cases of carcinoma, and two cases of melanoma. A monoclonal light chain expression was demonstrated in nine out of eleven B cell lymphomas. The three T-cell lymphomas all expressed pan T markers (CD 3) and two the T-helper antigen (CD 4). One patient had meningeal involvement of a true histiocytic lymphoma which was identified by its large atypical cells which were positive for alpha-1-anti-trypsin and muramidase. In four patients with a primary diagnosis of acute lymphoblastic leukemia, CSF involvement was confirmed by the demonstration of blasts with CD 10 (cALLA) or light chain restriction. Epithelial or melanocytic markers were demonstrated on the tumor cells in CSF from the remaining four patients. In 29 CSF specimens a diagnosis of reactive lymphocytosis was made using cytomorphology which mostly was characterized by macrophages mixed with small mature lymphoid cells. Immunologic evaluation showed that these mature cells were CD 10 negative T-cells and only few specimens contained polyclonal B-cells. The subsequent clinical course of these patients showed no evidence of CNS malignancy. It is concluded that cytology should be used in conjunction with immunocytochemistry to accurately evaluate CSF specimens from patients with possible malignant meningitis.
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7789238
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[Usage of the geno-toxicological studies in the biological evaluation of dental materials].
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The salmonella mutagenicity test (Ames test), the Bacillus subtilis repair test and SOS chromotest are three sorts of sort-term mutagenic test, which were developed recently and had their individual terminal point to examine genotoxins. A battery of short-term tests was made up of these three mutagenic tests to examine the mutagenicity of formaldehyde, glutaraldehyde and resorcinal. The results verified formaldehyde and glutaraldehyde were genetoxins, and discovered resorcinal not only had no mutagenicity, but also had the antimutagenicity to some genotoxic agents. In addition, the methods of three tests were described and the use of the battery was introduced and evaluated.
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7789235
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[Relationship between levels of aspartate aminotransferase in gingival crevicular fluid and periodontal disease activity].
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This paper describes a longitudinal study in which clinical parameters and aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) were monitored bimonthly over a 6-12 months period in 970 sites from 7 treated periodontitis patients. In this study, 21 out of 970 sites exhibited new attachment loss (AL) of at least 2mm between two consecutive visits. The GCF-AST levels and clinical parameters at sites with active tissue destruction (> or = 2mm AL within two months) were significantly higher than those at control sites on the same tooth. The GCF-AST levels and clinical parameters at sites with active tissue destruction decreased significantly after re-treatment. The measurement of GCF-AST could be an useful adjunctive criterion for detection of disease activity. However, it seems to be unsatisfactory in predicting disease activity.
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7789232
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[The effect of measuring the curvature of soft palate to determine the position of posterior peripheral seal].
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This study was undertaken to determine the feasibility of the surveyor of curvature in fabricating a full upper denture. 48 cases were investigated to determine the position of the posterior peripheral seal with the instrument. The results showed that the retention of the full upper denture was greater than that of the control-team. This method is more suitable for the patients with lower flat or higher palatal vault.
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7789231
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[The effect of sagittal split ramus osteotomy advancement and setback mandible on occlusal force and masticatory efficiency].
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21 patients (mandibular prognathism = 11, mandibular retrognathism = 10) whose occlusal force and masticatory efficiency were measured and analysed preoperatively, three and six months following sagittal split ramus osteotomy. The result shows that, in individuals with mandibular retrognathism treated by lengthening of the mandible, the occlusal force and masticatory efficiency would decrease, in individuals with mandibular prognathism treated by reduction in mandibular length, the occlusal force and masticatory efficiency would increase. There is no linear correlation relationship between the change of the occlusal force and the movement of the angle and the distance of the mandible.
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7789230
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[Application of T-subgroup cells assay in the immunology of oral-maxillofacial cancer].
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We report on T-subgroup cells in 70 cases of oral-maxillofacial cancer determined by T-monoclone antibody-OKT system. The results are as follows: CD3, CD4/CD8 value of cancer patients was decreased significantly, compared with that of health or oral benign tumor patients. CD8 was significantly increased (P < 0.001); however, CD8 was decreased and CD4/CD8 ratio was increased after operation. 20 cases underwent the dynamic testing, determined in 1 week, 1 and 3 month. The results are as follows: CD3, CD4, CD4/CD8 values were increased gradually and CD8 was decreased gradually in 17 cases of curative patients, but CD4, CD4/CD8, values were decreased and CD8 was increased significantly in 3 cases of metastased patients. Our conclusion is that determination of T-subgroup cells is of reference value for monitoring and treating cancer patients.
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7789229
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[Evaluation of presurgical orthodontic correction of the mandibular prognathism].
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The aim of this study was to evaluate the effects of presurgical orthodontic correction of the mandibular prognathism. The sample consisted of two groups of surgical cases. The cases of the mandibular prognathism in group I with lower anterior dental compensation received presurgical orthodontic decompensation, and the cases in group II without lower anterior dental compensation did not receive presurgical orthodontic decompensation. The results showed that before presurgical orthodontic treatment, significantly differences existed between the two groups variable ILi/OL and ANB. After presurgical orthodontic correction lower incisors position in group I was very close to that in the group II, this means that the presurgical orthodontic treatment significantly changed the position of the lower incisors.
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7789227
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[Expression of proliferating cell nuclear antigen (PCNA) in squamous cell carcinoma of the oral cavity].
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Proliferating cell nuclear antigen (PCNA) was identified by immunohistochemistry in 52 cases. PCNA-positive cells had been detected in the basal cells of normal epithelium known to contain proliferating cells. PCNA scores of normal epithelium was 1 as "low", and carcinomas were 3 or 4 as "high". The PCNA scores of high-grade carcinoma was significantly higher than the low-grade carcinoma. The study shows that expression of PCNA correlated with carcinoma grade.
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7789225
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[The changing of orofacial structure by bite opening with Begg technique].
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Cephalometric study of 30 deep-bite cases treated with extraction of four first premolars and Begg stage I appliance shows that the bite opening consists of not only intrusion of the upper and lower incisors but also extrusion of the upper and lower molars, furthermore, the lower incisors depressed more than the upper ones and the lower molars are elevated more than the upper ones. The moving type of teeth, the changing of base bone and soft tissue profile are also discussed in this article.
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7789224
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[Experimental study on immediate endosseous implantation].
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Screw type implants (ITI series) were implanted into the socket of extracted teeth of adult dogs to investigate the histologic recovery process of implantation. Two groups of immediate implantation. (with or without filling of cancellous bone chips) were performed, with a follow-up period of one month and three months. Results showed that marked immature new bone formation was found one month later after implantation. The amount of new bone in the group with cancellous bone implantation was much more than that in the group without bone chips. Mature new bone was observed three month later after operation, no marked difference was found in the amount of new bone between the two groups.
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7789221
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Epidemiology of Helicobacter pylori infection in the People's Republic of China.
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This paper presents a general review of the studies on the epidemiology of H. pylori infection in China. Among 3,519 dyspeptic individuals presenting for endoscopy, H. pylori detectable rate was 61.2%. A higher prevalence of infection was found in patients with peptic ulcer. The prevalence of gastric metaplasia was 82.5% in patients with duodenal ulcer, 53.1% in duodenitis and 34.5% in normal duodenal mucosa. H. pylori infection is significantly more common in gastric cancer patients (58.9%) than in the matched controls (42.5%). Endoscopic studies performed on asymptomatic volunteers aged 10-25 showed that the prevalence of gastritis and H. pylori was 45%-84% and 42%-67% respectively. Large scale prospective studies of the possible role of H. pylori in gastric cancer in populations with various gastric cancer mortality rates using ELISA assays showed a significant geographical association between gastric cancer mortality and the prevalence of H. pylori infection. H. pylori infection is acquired at an earlier age and has a higher prevalence in the high gastric cancer risk areas than in the low risk areas. H. pylori was detected in human saliva and dental plaque by PCR. H. pylori-like organisms were successfully isolated by culture and detected by nested PCR in the gastric mucosa of pigs and cats. Intrafamilial clustering of H. pylori infection was observed.
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7789220
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Serological survey of nasopharyngeal carcinoma in 21 cities of south China.
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This paper reports the results of serological survey of 318,912 persons for nasopharyngeal carcinoma (NPC) in 21 cities and counties of south China. There were 8,441 persons with positive VCA-IgA antibody (single item positive) of EB virus (EBV), with a rate of 2.65%. In these VCA-IgA positive persons, 287 persons also had positive EA-IgA (double items positive) of EBV. The overall positive rate was 0.09%. 100 cases of NPC were found and 87 of them (87.0%) were in early stage. NPC found in the group with single item positive accounts for 1.19%, but the rate in the group with double items positive was 19.16% (55 cases). In NPC patients with double items positive, 49 cases were in early stage (89.1%). In 100 cases of NPC found, 45 cases appeared with negative EA-IgA, only with positive VCA-IgA, which indicated that for diagnosis of NPC, sensitivity of EA-IgA was lower than that of VCA-IgA, but its specificity was higher. Therefore, both can increase the detecting rate and early diagnosis rate of NPC. The age of people checked varied with different antibody positive rate and NPC detecting rate. The three items showed a positive correlation. The results are compatible with those of the prospective study for NPC in Wuzhou City, Guangxi, China. The method for NPC serological diagnosis can be extended and applied to raise the NPC detecting rate and early diagnosis rate at secondary prevention. And, it is further proved that there is a close relationship between NPC and EBV.
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7789219
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Progress in surgical treatment of hydatid diseases in China. A clinical analysis of 22,005 surgical cases.
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Altogether 27,716 cystic hydatid cases and 445 alveolar hydatid cases clinically diagnosed and surgically treated in China were retrospectively studied. In accordance with the parasitic sites of the hydatid cysts and the various pathological types, different surgical procedures were adopted. In an attempt to prevent intraoperative accidents and postoperative complications, continued improvements in operational techniques have been made. Different surgical procedures were evaluated for their advantages and disadvantages as well as their indications. According to the pathological changes of the residual cavities of ectocysts, different measures were adopted. In screening operations, injection of antihydatid drug into hydatid cysts followed by oral administration of this drug was used to prevent relapses. The therapeutic effect of all these measures has been proved satisfactory by follow-up studies. This indicates that the progress in surgical treatment of cystic hydatid disease during the recent 10 years has been attaining to the objectives of shortening the duration of treatment, decreasing the postoperative recurrence rate and increasing the cure rate. In some hospitals, no operative death and relapse of cyst growth have been reported in nearly 1,000 surgical cases of cystic hydatid disease. Only 10.8% of the 445 alveolar hydatid cases underwent radical operations and the prognoses were unfavourable. This was due to the absence of symptoms in early stages of the disease which often made the patients miss the chance for radical operation in hospitals.
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7789217
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Endogenous porphyrins in murine skin and transplanted PAM-212 squamous cell carcinoma tissues after injection of delta-aminolevulinic acid.
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After intraperitoneal (IP) injection of delta-aminolevulinic acid (ALA), the endogenous porphyrins in murine skin and tumor tissues were determined by a method involving solvent and acid extractions. The results showed that the total amount of porphyrins in the tumor tissues after ALA injection was much higher than that in the skin from the same mice, although the amount of porphyrins in the skin from the ALA-injected mice was higher than that from the saline-injected (control) mice. The porphyrins in the tumor were mostly protoporphyrin and coproporphyrin, with only a small amount of uroporphyrin. The optimum period for porphyrin accumulation in the tumor as well as in the skin was 1 hour after the injection of ALA. As the period was extended to 3 and 6 hours, the amount of porphyrins in these tissues decreased considerably. These findings could be valuable for further application of ALA in the photodynamic therapy of skin cancer.
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7789216
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Changes of gastric acid secretion and somatostatin after Roux-en-Y cholangiojejunostomy.
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The authors studied the changes of gastric acid secretion and determined the levels of somatostatin (SS) and gastrin (Gn) in blood, gastric juice and pyloric antrum in 28 patients Roux-en-Y with cholangiojejunostomy (CJR-Y). Gastric acid hypersecretion was identified, and the level of SS was found dropped while the content of Gn increased in these specimens. It was considered that the reduction of SS synthesis and secretion might have a key effect on the mechanism of secondary gastric acid hypersecretion in patients after CJR-Y.
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7789215
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Extensive wound excision in shock stage in patients with major burns.
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To stop excessive plasma loss, alleviate noxious effects of devitalized tissues on the body and shorten the hospitalization time, we performed extensive escharectomy during the shock period in extensively burned patients. Group A consisted of 21 patients aged 9-45 years (26.1 +/- 7.9 years), with a mean total burn area of 63.2% +/- 18.1% TBSA, and full-thickness injury involving 35.9% +/- 19.6% TBSA. The first escharectomy was done at 24.1 +/- 13.9 hours postburn, and excision area averaged 32.3% +/- 6.7% TBSA (24%-46%). In 15 of them, Swan-Ganz catheter was introduced to monitor the hemodynamic changes. It was found that RAP, PAP, PAWP, ABP, HR, CO and CI were all stable during and after the operation. Group B consisted of 29 patients aged 11-50 years (30.4 +/- 11.7 years), in whom escharectomy was begun 4-5 days postburn. The mean healing time of the patients in group A was 33.1 days, shorter than that of group B patients (40.1 days). The duration of hemoconcentration was shorter in group A. The amount of blood transfusion was almost 700 ml less in group A during the first two weeks. Less antibiotics were used with fewer visceral complications in group A. We believe that escharectomy during the burn shock stage is feasible.
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7789214
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Identification and classification of Neisseria gonorrhoeae by RAPD fingerprinting.
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Using the RAPD method, we identified and classified Neisseria gonorrhoeae on the basis of the DNA level. Except OPG20 the other 19 primers of OPG arbitrary primer kit showed informative arrays of amplified prominent segments. Most of the segments were common to all three Neisseria gonorrhoeae groups; some segments were amplified from two groups or only one group so that the fingerprint maps of different Neisseria gonorrhoeae groups were distinctive. Based on these findings, i.e. on the genomic level, we can classify the three Neisseria gonorrhoeae groups. Using OPG10 and OPG11 to amplify the five Neisseria species, we found marked diversity among them, which made it easy for us to identify Neisseria gonorrhoeae from four other Neisseria species. The use of the RAPD method needs some special reaction conditions, e.g. annealing temperature that should not be too low or too high and should be consistently stable. The quality of Taq polymerase is also very important. The reproducibility of the results under these conditions was very good.
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7789212
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GM1 antibody in Guillain-Barre syndrome after Campylobacter jejuni infection.
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Fecal culture of Campylobacter jejuni was prepared by the method of Skirrow, and serum class specific antibodies (IgG, IgM and IgA) to Campylobacter jejuni and serum class specific antibodies (IgG IgM) to GM1 were prepared with solid phase enzyme linked immunasorbent assay in 16 cases of Guillain-Barre syndrome (GBS), 32 controls with other neurological diseases (disease controls) and 90 normal controls. The results showed that the incidence of Campylobacter jejuni infection, especially recent infections, in the group with Guillain-Barre syndrome was much higher than that in the two control groups, and that the positive rate of GM1 antibody was also much higher in the GBS group than in the two control groups. The results suggest that Campylobacter jejuni infection may be one of the important precipitating factors of Guillain-Barre syndrome and play an important role in the epidemiological pattern of Guillain-Barre syndrome in China. It damages the myelin of peripheral nerves through induction of GM1 antibody production.
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7789213
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Effects of daurisoline on cytosolic free calcium in fetal rat cerebral cells.
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Cytosolic free Ca2+ ([Ca2+]i) was measured in dissociated cerebral cells isolated from fetal rats with the fluorescent indicater fura-2. Increase in [Ca2+]i occurred rapidly following exposure of the cells to 50 mmol/L KCl, 10(-7) mol/L Bay K 8644 or 200 mumol/L glutamate (Glu). [Ca2+]i elevated by K(+)-depolarization was attenuated by pretreatment with 10(-7), 10(-6) mol/L daurisoline (Dau). The response of [Ca2+]i to K(+)-depolarization did not change when 10(-8) mol/L Dau was added. When 10(-8)-10(-6) mol/L Dau was added to the cell suspensions prior to exposure to Glu, the Glu-stimulated rises in [Ca2+]i were reduced significantly. However, Dau (10(-6), 10(-7) and 10(-8) mol/L) did not alter the response to Bay K 8644. These results indicate that Dau can inhibit the increase of [Ca2+]i in fetal rat cerebral cells induced by certain Ca2+ agonists, especially Glu, suggesting that this drug may have a protective effect against cerebral cellular injury.
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7789211
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Neurohypophysial AVP concentration in stroke patients.
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Neurohypophysial arginine vasopressin (AVP) concentrations were determined by RIA in 9 patients with cerebral infarction, 11 patients with intracerebral hemorrhage, 5 patients with subarachnoid hemorrhage and 5 control subjects. The results showed that neurohypophysial AVP concentration in patients with cerebral infarction increased by 225.8% as compared with the control subjects (P < 0.05), and the AVP concentrations in patients with intracerebral and subarachnoid hemorrhage did not change significantly. Brain herniation as a result of intracranial hypertension, gastrointestinal bleeding and hyperglycemia (two clinical manifestations of stress) was seen more frequently in hemorrhagic stroke patients than in ischemic stroke patients. These findings suggest that the ischemic brain damage may contribute to the elevation of neurohypophysial AVP concentration in patients with cerebral infarction.
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7789210
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Structure-function interrelation and clinical effect of atrial natriuretic peptide (ANP).
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Atriopeptin III (AP III) and its six analogues were synthesized by solid phase method and their diuretic and hypotensive activities were determined. Among these analogues, analogue [D-Ala-5, D-Arg-23] AP III was nearly 10 times as potent as AP III in diuretic activity while its hypotensive activity increased only 50% of that of AP III. Analogue des [Ser-15Gly-16Leu-17Gly-18Asn-20Ser-21] AP III was 15% as potent as AP III in diuretic activity, but it still maintained about 60% of the hypotensive activity of AP III. Meanwhile, we tried analogue [D-Ala-5, D-Agr-23] AP III for the treatment of hypertensive syndrome in pregnancy and obtained some good results.
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7789205
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The organization of reactivated memory in infancy.
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The specificity of memory retrieval by 3-month-old infants was examined in 3 experiments. All infants were trained in the mobile conjugate reinforcement paradigm to kick their feet to produce movement in an overhead crib mobile and were tested 2 weeks later. 24 hours prior to the test, subjects received a 3-min reminder treatment. The results of Experiment 1 demonstrated that only the moving training mobile alleviated forgetting after the 2-week retention interval; forgetting was not alleviated by exposure to the stationary training mobile or to the mobile stands and ribbon alone. The results of Experiments 2 and 3 demonstrated that, once retrieved, the reactivated memory was highly specific to the conditions of original training. Furthermore, the memory attributes that were the last to be forgotten (e.g., the general or global features) were the first to be retrieved following the reminder treatment. Conversely, those memory attributes that were forgotten first (e.g., the specific or local details) were the last to be retrieved. These findings have important implications for infant memory retrieval, reminiscence, and infantile amnesia.
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7789204
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The role of age and verbal ability in the theory of mind task performance of subjects with autism.
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A number of studies have reported that most children with autism fail theory of mind tasks. It is unclear why certain children with autism pass such tests and what might be different about these subjects. In the present study, the role of age and verbal ability in theory of mind task performance was explored. Data were pooled from 70 autistic, 34 mentally handicapped, and 70 normal young subjects, previously tested for a number of different studies. The analysis suggested that children with autism required far higher verbal mental age to pass false belief tasks than did other subjects. While normally developing children had a 50% probability of passing both tasks at the verbal mental age of 4 years, autistic subjects took more than twice as long to reach this probability of success (at the advanced verbal mental age of 9-2). Possible causal relations between verbal ability and the ability to represent mental states are discussed.
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7789203
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A twin-sibling study of observed parent-adolescent interactions.
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Numerous behavioral genetic studies call attention to the strong and pervasive genetic influence on developmental characteristics. However, this research has been criticized for its use of poor environmental measures and a failure to examine the complex processes that are a hallmark of research in child development. This study addresses this criticism by examining the genetic and environmental components of parent-child interactions. Mother, father, and 2 adolescent siblings (10-18 years) from each of 675 families were observed interacting in 10-min dyadic problem-solving sessions. 6 groups of siblings that differed in genetic relatedness were examined (MZ and DZ twins, full siblings in nondivorced families; full, half, and unrelated siblings in stepfamilies). Results suggest a greater genetic component to adolescent behavior than to parent behavior. Both adolescent and parent behavior showed strong effects of nonshared environment, even after error of measurement was removed.
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7789202
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A contextual-moderator analysis of emotional autonomy and adjustment in adolescence.
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This study investigated the relation between emotional autonomy, as measured by Steinberg and Silverberg's Emotional Autonomy Scale (EA), and adolescent adjustment as moderated by several individual, familial, and cultural contexts. Subjects were 96 adolescents (10-18 years old) and their mothers and teachers. Results indicate that when the affective nature of the parent-adolescent relationship is positive (e.g., maternal warmth is high or intensity of parent-adolescent conflict is low), positive adolescent adjustment is more likely when adolescents report less emotional autonomy. On the other hand, when the family environment is more stressful, emotional autonomy is positively associated with adolescent adjustment. Findings suggest that higher scores on the EA scale index emotional detachment from parents and that such detachment is detrimental in supportive familial environments but adaptive in less supportive familial environments. That emotional detachment from parents appears to serve a protective function in certain stressful situations is viewed as analogous to the adoption of an avoidant attachment strategy during infancy.
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7789201
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Socioeconomic disadvantage, proximal environmental experiences, and socioemotional and academic adjustment in early adolescence: investigation of a mediated effects model.
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This study investigated interrelations among conditions of household socioeconomic disadvantage, proximal environmental experiences, and adaptational outcomes in a sample of 398 middle grade, early adolescents from a predominantly poor, rural area. Findings indicated that levels of disadvantage were related to both socioemotional and academic adjustment, with those from relatively disadvantaged backgrounds faring most poorly. Specifically, youth from homes in which adults were employed in low-income, unskilled occupations were found to have lower levels of school performance and achievement compared to those from homes in which adults were employed in higher paying semi-skilled or skilled/professional occupations. Further, youth from families in which neither parent had graduated from high school exhibited significantly worse socioemotional and academic adjustment than did those whose parents had higher educational levels. Youth who lived in relatively disadvantaged homes also reported more negative experiences of proximal environmental conditions relating to family and school contexts and greater exposure to stressful life events. Most notably, findings provided support for employing an ecological-mediational perspective to understand patterns of linkage between socioeconomic disadvantage and levels of adjustment. Support for this viewpoint included the finding that proximal environmental experiences were significant predictors of adolescent adjustment, independent of shared variance with conditions of household disadvantage, whereas conditions of disadvantage in several instances were no longer related significantly to indices of adjustment once their association with proximal environmental conditions was taken into account. The discussion considers implications for the targeting and scope of ecologically oriented approaches to preventive intervention.
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7789200
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The academic lives of neglected, rejected, popular, and controversial children.
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The purposes of this study were to examine academically relevant characteristics of different sociometric status groups and to learn about the academic orientations of behavioral subgroups of rejected children. Results from a sample of 423 sixth and seventh graders (ages 11-13) suggested that sociometrically neglected children have quite positive academic profiles. When compared with average status children, these students reported higher levels of motivation, were described by teachers as more self-regulated learners, as more prosocial and compliant, and as being better liked by teachers. Analyses of two behavioral subgroups of rejected children indicated that aggressive-rejected but not submissive-rejected children have problematic academic profiles. Relations of neglected and aggressive-rejected status to academic adjustment in young adolescents' lives is discussed.
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7789198
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Meeting goals and confronting conflict: children's changing perceptions of social comparison.
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It was proposed that previously observed grade-related changes in children's social comparison behavior could be explained by the changing goals and meanings children assign to this behavior. Specifically, it was suggested that, as children progress through the school system, they become increasingly aware of the negative and positive aspects of social comparison and adjust their behavior in response to this awareness, as well as to increasingly salient self-evaluation goals. To examine these propositions, 106 elementary school children were observed in their classrooms and interviewed once a year for 3 years. Consistent with previous research, overt forms of social comparison were most frequent among younger children, whereas subtle forms of social comparison were most frequent among older children. Furthermore, with increasing grade children were likely to view overt forms of social comparison negatively and subtle forms as useful in meeting self-evaluation goals. Additional analyses revealed little association between perceptions of social comparison and actual social comparison behavior, except that perceiving subtle social comparison as useful for self-evaluative goals predicted engagement in such behavior 2 years later.
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7789199
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Mother-child interaction quality as a partial mediator of the roles of maternal depressive symptomatology and socioeconomic status in the development of child behavior problems. Conduct Problems Prevention Research Group.
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This investigation examined the relation between maternal depressive symptomatology and the development of externalizing behavior problems in children by incorporating mother-child interaction quality into a series of models. A representative sample of 376 first-grade boys and girls (mean age = 6.52) from diverse backgrounds (234 from the lowest 2 socioeconomic classes) and their mothers completed an interaction task designed to measure the quality of mother-child interaction. Latent variable structural equations analyses revealed that mother-child interaction quality partially mediated the relation between maternal depressive symptomatology and child behavior problems even when the effects of socioeconomic status on both variables were taken into account. Although this model held for boys, girls, and Caucasians, the relation between maternal depression and interaction quality was not significant for African-Americans. Further investigation is required to understand the lack of generalizability of the model to African-American mother-child dyads.
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7789197
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Relational aggression, gender, and social-psychological adjustment.
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Prior studies of childhood aggression have demonstrated that, as a group, boys are more aggressive than girls. We hypothesized that this finding reflects a lack of research on forms of aggression that are relevant to young females rather than an actual gender difference in levels of overall aggressiveness. In the present study, a form of aggression hypothesized to be typical of girls, relational aggression, was assessed with a peer nomination instrument for a sample of 491 third-through sixth-grade children. Overt aggression (i.e., physical and verbal aggression as assessed in past research) and social-psychological adjustment were also assessed. Results provide evidence for the validity and distinctiveness of relational aggression. Further, they indicated that, as predicted, girls were significantly more relationally aggressive than were boys. Results also indicated that relationally aggressive children may be at risk for serious adjustment difficulties (e.g., they were significantly more rejected and reported significantly higher levels of loneliness, depression, and isolation relative to their nonrelationally aggressive peers).
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7789196
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Young children's understanding of the causes of anger and sadness.
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This study investigated kindergarten children's understanding of the causes of anger and sadness. Previous research has shown that before 6 or 7 years of age, children have difficulty distinguishing hypothetical situations designed to evoke anger from those designed to evoke sadness. In this project, 80 kindergarten children (ages 5-1 to 6-5, M = 5-10) predicted and explained protagonists' emotional responses to a variety of hypothetical events. The results showed that intentional harm was not the feature young children used to distinguish anger from sadness. Children predicted anger most often when they believed that protagonists could change undesirable situations and reinstate their goals and when children focused on the person or conditions that brought about undesirable situations. Children predicted sadness most often when they believed that goal reinstatement was impossible and focused on the losses that would ensue as a result.
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7789195
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Priming of perceived control in young children as a buffer against fear-inducing events.
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Young children (aged 5 and 6) watched videotaped fairy tales that acted to prime child control versus adult control over frightening events. Subsequently, they watched an ambiguous videotape of a child having a medical exam; tapes were varied for presence or absence of fear cues (facial expressions shown by actors). We predicted that children primed for child control versus adult control would show information-processing error patterns that paralleled those previously found for children who were dispositionally high or low in perceived control. As expected, children primed for child control showed processing enhancement whereas those primed for adult control showed processing deficits after witnessing fear cues. Attentional disengagement was found to mediate processing errors. Perceived control--dispositional or temporary--was interpreted as an important organizer of attention to and processing of potentially threatening events.
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7789194
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What do children worry about? Worries and their relation to anxiety.
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This study examined worry in elementary school aged children and its relation to anxiety. The study also examined whether parameters of excessive or dysfunctional worry could be delineated. Children from second through sixth grades (ages 7-12 years) were interviewed using a structured approach and completed several child anxiety measures. Parameters of worry assessed included: number of worries, areas of worry, intensity of worries, and perceptions of the frequency of worry events. Findings revealed few age-related differences but found that girls reported more worries than boys and that African-Americans reported more worries than white or Hispanic children. The three most common areas of worry involved School, Health, and Personal Harm. Anxiety was significantly associated with worry, providing empirical support for a link between these two constructs. Worry parameters, especially number and intensity of worries, could differentiate high and low anxious children in a normal school sample. Implications of these findings for understanding the role of worry in childhood anxiety are discussed.
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7789193
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Developmental change in infants' responses to stress.
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Infant stress responses to a well-baby physical examination and inoculation were observed longitudinally at 2, 4, and 6 months of age. In general, there were cortisol increases over base to the procedures. Cortisol level and cortisol response decreased with age. These data indicate a developmental shift in adrenocortical functioning between 2 and 6 months of age. Further evidence for this shift was seen in the stability of individual responses between 4 and 6 months of age. Individual differences in both cortisol and behavioral responses showed the most stability between these 2 ages. Moreover, diurnal variation in baseline cortisol level was present only at 6 months of age. While a sizable minority of infants showed stress-related cortisol decreases to the procedures at a given age, there was no evidence for cross-age consistency in individual infants showing these cortisol decreases.
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7789192
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The determinants of coparenting in families with toddler boys: spousal differences and daily hassles.
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In order to advance understanding of the phenomenon of coparenting, naturalistic observations of firstborn sons were undertaken when they were 15 months of age at a time when both parents were home and family life was demanding. Narrative records of coparenting events were scored to determine the frequency with which parents supported and undermined each other and to test two hypotheses pertaining to individual differences in coparenting: that greater differences between spouses in demographic factors, personality, styles of relatedness and child-rearing attitudes would forecast more unsupportive and less supportive coparenting; and that the adverse effects of such spousal differences would be amplified by high levels of family stress, as indexed by frequency and intensity of daily hassles. Both hypotheses received support and are discussed in turn.
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7789190
|
Molecular characterization and refined genomic localization of three human potassium ion channel genes.
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Potassium ion (K+) channels are essential for a variety of cellular functions in both excitable and non-excitable cells and are likely to be involved in the pathogenesis of some cardiovascular and neurological disorders. To be useful in candidate gene analysis of inherited diseases it is important to identify new K+ channel genes and localize these sequences on the human physical and genetic maps. Using fluorescence in situ hybridization (FISH), we mapped two new K+ channel gene containing cosmids, c2-3a and c9-2a, to chromosomes 1 and 19, respectively. Partial DNA sequencing (c2-3a) and restriction enzyme site analysis (c9-2a) established the uniqueness of each clone. We refined the localization of c2-3a, c9-2a and a previously described K+ channel gene KCNA5, (c7-2), by performing contour length measurements of hybridized metaphase chromosomes and determining the average FLpter% value (fractional length relative to the fixed reference point pter x 100%). When compared to ideograms of banded metaphase chromosomes, these FLpter% values correspond to 12p13.31-->p13.33, 1p13.1-->p21.1 and 19q13.32-->q13.33, respectively. Using FISH, each of these clones has been finely mapped to a different human chromosome indicating a significant dispersion of K+ channel sequences in the human genome.
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7789191
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Function and content of maternal demands: developmental significance of early demands for competent action.
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The sources and effects of mothers' demands upon children were examined during naturalistic interactions of 70 mothers and their 1 1/2-3 1/2-year-olds. Demands were categorized in terms of immediate function (e.g., do's vs. don'ts) and content area emphasized by mothers (e.g., competent action, appropriate behavior, caretaking). Children's age and oppositional behavior influenced the nature of mothers' demands. Mothers with authoritative child-rearing attitudes emphasized proactive, competence-oriented demands and avoided regulatory controls. Maternal demands for competent action (prosocial behavior, chores, cognitive/play) predicted enhanced compliance and fewer behavior problems at age 5. Demands focused on the regulation of personal and social behavior predicted more behavior problems at age 5. We propose that children's personal and social competence emerges from pressures for instrumentally competent behavior in a harmonious interactive context.
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7789189
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Assignment of the gene (GLCLC) that encodes the heavy subunit of gamma-glutamylcysteine synthetase to human chromosome 6.
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Assignment of the human gene (GLCLC) that encodes the heavy or catalytic subunit of gamma-glutamylcysteine synthetase (glutamate-cysteine ligase; EC 6.3.2.2) to human chromosome 6 was accomplished by hybridization to Southern blotted somatic cell hybrid DNA. This assignment was confirmed by PCR from somatic cell hybrid DNAs.
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7789188
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Viability, development and incidence of chromosome anomalies of preimplantation embryos from XO mice.
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We examined the viability and developmental status of XO embryos at preimplantation stage (day 3 of gestation) by assessing blastocyst formation and counting cell number using our XO mouse colony. We also examined the incidence of chromosome anomalies. Embryos from XO mice (XY, XX and XO) developed more slowly (in cell numbers and blastocoele formation) than those from XX mice (XY and XX). XO embryos also tended to develop more slowly than XX embryos in the XO group. Although litter size at the preimplantation stage of gestation was almost twice as large (12.7) as those at mid-gestation (7.6) and near-term (7.2) in this colony, the adjusted XY:XX:XO ratio (2.8:2.0:1.0) did not differ greatly. This indicates that almost half of the embryos must have been eliminated during the first half of gestation in the XO group, probably regardless of sex chromosome complements. Thus, we consider that maternal XO sex chromosome constitution is disadvantageous for the intrauterine development of the embryo during the early period of gestation. This may be related to precocious aging of XO mice. Further, we confirmed that a high incidence of abnormal karyotypes occurs in embryos from our XO mouse colony.
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7789185
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Rabl orientation of CENP-B box sequences in Tupaia belangeri fibroblasts.
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The chromosomes of the tree shrew Tupaia belangeri exhibit highly localized CENP-B box sequences in the centromeric regions of most chromosomes. Telomeric sequences are present at the ends of all chromosomes and, in addition, at specific interstitial chromosomal sites that likely represent remnants of ancestral telomeres. This suggests that Robertsonian and tandem chromosome fusion events have occurred in the karyotypic evolution of Tupaiidae. In Tupaia skin fibroblasts CENP-B boxes are almost always clustered together at one pole of the interphase nucleus, whereas the telomeric domains are relatively evenly distributed throughout the whole nuclear volume. The observed orientation of the centromeres is reminiscent of the Rabl polarization of chromosomes; this is the first mammalian cell substrate in which such an higher-order chromosomal organization has been observed. CENP-B box sequences are found in several other mammalian species. The implications for recent parallel evolution of CENP-B binding motifs and concerted evolution of these sequences are discussed.
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7789187
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Identification of p and q arms of the blesbok (Damaliscus dorcas phillipsi, Alcelaphinae) RBG-banded chromosomes with comparison to other wild and domestic bovids.
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The RBG banded karyotype (2n = 38) of the blesbok (Damaliscus dorcas phillipsi) comprises 8 pairs of metacentric, 3 pairs of submetacentric and 7 pairs of acrocentric autosomes. The X and Y chromosomes are acrocentric. The 11 pairs of biarmed chromosomes correspond to Robertsonian translocations involving the chromosomes equivalent to goat and cattle chromosomes: 1;10, 4;5, 8;17, 7;9, 6;14, 13;15, 12;16, 20;22, 3;19, 2;27 and 11;23. The comparison of Blesbok karyotype with that of other species of Alcelaphinae and Hippotraginae reveals a high level of homoeology.
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7789186
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Chromosomal localization of a gene, GF1, encoding a novel zinc finger protein reveals a new syntenic region between man and rodents.
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The Gfi1 gene encodes a zinc finger protein which binds DNA and is involved in transcriptional regulation. Gfi1 was assigned to the central portion of mouse Chr 5 by interspecific backcross mapping and to human chromosome band 1p22 and rat chromosome band 14p22 by fluorescence in situ hybridization (FISH). Comparative mapping data presented here describes a new syntenic region between man and rodents.
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7789184
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Localization of the human stem cell tyrosine kinase-1 gene (FLT3) to 13q12-->q13.
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We have previously reported the cloning of stem cell tyrosine kinase-1 (STK-1, gene symbol FLT3), the human homolog of the mouse Flk2/Flt3 gene (Small et al., 1994). This growth factor receptor is expressed in CD34+ human bone marrow (stem/progenitor) cells. We have mapped the gene for STK-1 using PCR screening of a human-rodent somatic cell hybrid panel, and fluorescence in situ molecular hybridization (FISH) of STK-1 genomic probes to mitotic chromosomes of normal human lymphocytes. The results of both analyses show that the gene for STK-1 (FLT3) localizes to chromosome 13q12-->q13.
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7789183
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Chromosomal mapping of the genes GPRK5 and GPRK6 encoding G protein-coupled receptor kinases GRK5 and GRK6.
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G protein-coupled receptor kinases (GRKs) play an important role in phosphorylating and regulating the activity of a variety of G protein-coupled receptors. Chromosomal mapping of the human genes for the two most recently identified members of the GRK family, GRK5 (GPRK5) and GRK6 (GPRK6), was accomplished by correlation of the presence of the GPRK5 and GPRK6 loci with specific chromosome regions in a rodent-human hybrid panel. These analyses revealed that GPRK5 maps to chromosome region 10q24-->qter while GPRK6 maps to 5q35. A GPRK6 related locus maps to 13pter-->q21.
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7789182
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The human calcitonin receptor gene (CALCR) at 7q21.3 is outside the deletion associated with the Williams syndrome.
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The human calcitonin receptor (CTR) is a transmembrane peptide with dual action as a receptor for the hormone calcitonin and as an extracellular calcium sensor. Therefore, CTR dysfunction could lead to disorders of calcium metabolism associated with hypercalcemia, such as the Williams syndrome (WS). WS is a developmental disorder caused by a deletion at chromosome 7q11.23 that includes the elastin locus (ELN). We have mapped the CTR gene (CALCR) to chromosome band 7q21.3 by polymerase chain reaction and single-strand conformation analysis of somatic cell hybrids as well as fluorescence in situ hybridization (FISH) to metaphase chromosome spreads. Two-color FISH cohybridizing CTR and ELN probes confirmed that CALCR maps telomeric to ELN. Subsequent analysis of chromosome spreads from four WS patients revealed deletion of the ELN locus in all of them and normal hybridization of CTR probes to both chromosome 7 homologues, indicating that CALCR lies outside the deleted region.
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7789181
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Clarification of dubious karyotypes in Hodgkin's disease by simultaneous fluorescence immunophenotyping and interphase cytogenetics (FICTION).
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Cytogenetic studies on Hodgkin's disease (HD) typically reveal very complex karyotypes with a variety of numerical and structural abnormalities. The confusing thing is that about 10% of cases contain relatively discrete chromosome aberrations, for example a simple trisomy or loss of one single chromosome. Whether these karyotypes really correspond to Hodgkin and Reed-Sternberg (HRS) cells is uncertain. They could, for example, represent early stages in the evolution of the karyotype of the pathognomonic HRS cells. On the other hand, they could be artificial events that occur during the cytogenetic procedure. In our experience, isolated loss of the Y chromosome is the most frequent finding of this type. This aberration is usually considered to be a preparation artifact. However, if one takes into account that in HD up to 50% of male cases with complex karyotypes also lack the Y chromosome, a possible relation to HRS cells must be considered. The technique of simultaneous fluorescence immunophenotyping and interphase cytogenetic analysis (referred to as FICTION) is a powerful tool for studying the nature of cytogenetically abnormal cells. With the FICTION technique we studied four cases of HD in which the chromosome analysis had shown only the loss of the Y chromosome. Our aim was to clarify whether these karyotypes corresponded to the CD30-positive HRS cells. In two cases we found that HRS cells actually lacked the Y chromosome. There was strong evidence, however, that the HRS cells additionally had other chromosome aberrations and thus could not correspond to the cytogenetically determined karyotypes.
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7789180
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Comparative mapping of the immunoglobulin C epsilon 1 gene (IGHE) in five species of nonhuman primates by fluorescence in situ hybridization.
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The orthologous immunoglobulin C epsilon 1 gene (IGHE) of the common chimpanzee, pygmy chimpanzee, orangutan, white-handed gibbon, and Japanese macaque was assigned to the human chromosome 14 homologue in each species and regionally mapped by fluorescence in situ hybridization to PTR15q32 (common chimpanzee), PPA15q32 (pygmy chimpanzee), PPY15q32 (orangutan), HLA17qter (white-handed gibbon), and MFU7q29 (Japanese macaque). The gene localized to the terminal region of the chromosome in each species, and so this probe provides a new telomeric DNA marker for nonhuman primates.
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7789179
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Molecular cloning, characterization, and chromosomal mapping of a novel human gene (GTF3A) that is highly homologous to Xenopus transcription factor IIIA.
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We have isolated a novel human cDNA that is highly related to Xenopus transcription factor IIIA (TFIIIA). This clone contains an open reading frame of 1,269 nucleotides encoding 423 amino acids, including nine repeats of the Cys2His2-type of zinc-finger domain. A comparison of its sequence with Xenopus TFIIIA revealed 63% identity in nucleic acids and 58% identity in amino acids over a large portion of the gene and predicted peptide, indicating that the human homologue is likely to function as a transcription factor. The zinc-finger domains of the predicted protein also showed homology with those of human genes such as WT1, transcriptional repressor YY1, and MYC-associated zinc-finger protein (MAZ). Northern analysis showed expression in various tissues examined. The human TFIIIA gene (GTF3A) was localized to chromosome band 13q12.3-->q13.1 by fluorescent in situ hybridization (FISH).
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7789178
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Hemizygosity at the insulin-like growth factor I receptor (IGF1R) locus and growth failure in the ring chromosome 15 syndrome.
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The ring chromosome 15 syndrome is characterized by mild-to-severe growth failure. We evaluated the status of the insulin-like growth factor I receptor (IGF1R) gene, which had previously been assigned to band 15q26 in several patients with de novo ring 15 chromosomes, to investigate a possible correlation between disruption or loss of the IGF1R gene with the severe growth failure phenotype. The presence or absence of the IGF1R gene on the ring 15 chromosomes of five patients was ascertained by in situ hybridization and gene-dosage (Southern) blotting. The location of the breakpoints was determined by typing polymorphic markers from the distal end of the long arm of chromosome 15 in both the probands and their parents. Deletion mapping determined that all breakpoints were distal to D15S100 and that the IGF1R gene is located between D15S107 and D15S87. Three patients who had suffered severe growth failure in early childhood were hemizygous at the IGF1R locus, while one patient with borderline short stature had two copies of the IGF1R gene. The correlation between IGF1R gene dosage and growth retardation demonstrated here in our ring chromosome 15 patients suggests a possible role for heterozygous IGF1R gene mutations or deletions in other cases of unexplained growth failure.
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7789177
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PCR amplification and physical localization of the genes for pig FSHB and LHB.
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Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are members of the glycoprotein hormone family and play essential roles in gametogenesis and sexual development of mammals. Fragments of the porcine genes coding for the beta subunits of FSH and LH were amplified by PCR and used as probes for radioactive in situ hybridization in order to map these loci in the pig. Primers were chosen on the genomic DNA nucleotide sequences of FSHB and LHB as published in GenBank. Fragments of 1,127 bp (FSHB) and 1,239 bp (LHB) were cloned and verified by sequencing. FSHB was localized to pig chromosome bands 2p1.6-->p1.2 and LHB to pig chromosome band 6q2.1. The localization of LHB to the so-called halothane region of chromosome 6 could be expected from comparative mapping data. For FSHB, no conclusions can be drawn in this respect since, up to the present, too few genes are located on porcine chromosome 2.
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7789176
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Chromosomal assignment of the human deoxyribonuclease I gene, DNASE 1 (DNL1), to band 16p13.3 using the polymerase chain reaction.
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To localize the human deoxyribonuclease I (DNase I) gene, DNASE1 (DNL1), we performed a polymerase chain reaction (PCR) using DNA extracted from a panel of cloned human x rodent hybrid cell lines carrying different human chromosomes and screened for the presence of the expected PCR products. Two different sets of oligonucleotide primers specific for human DNase I cDNA sequences were used to amplify unique fragments in the human DNase I gene. Based on this work, DNL1 could be assigned to human chromosome 16. Furthermore, regional localization of the gene to 16p13.3 was performed by PCR analysis of a high-resolution mouse x human somatic cell hybrid panel that contained defined portions of human chromosome 16.
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7789175
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Localization of the human AHNAK/desmoyokin gene (AHNAK) to chromosome band 11q12 by somatic cell hybrid analysis and fluorescence in situ hybridization.
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Using a panel of somatic cell hybrids, we have mapped the locus for the AHNAK/desmoyokin gene (AHNAK) to human chromosome 11. Fluorescence in situ hybridization experiments independently confirmed the chromosomal localization and refined it to band 11q12.
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7789174
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Isolation and mapping of the human beta-signal sequence receptor gene (SSR2).
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We have isolated a human cDNA clone homologous to the canine beta-signal sequence receptor gene, which codes for an endoplasmic reticulum (ER) membrane protein associated with protein translocation across the ER membrane. Northern blot analysis revealed its ubiquitous expression in all organs examined. We also localized the human beta-signal sequence receptor gene (SSR2) to chromosome bands 1q21-->q23 by fluorescence in situ hybridization.
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