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8041443 | MRI in acute disseminated encephalomyelitis. | A retrospective analysis of CT and MRI studies in 12 patients with a clinical diagnosis of acute disseminated encephalomyelitis (ADEM) was performed. MRI was the definitive modality for the assessment of the lesions of ADEM: all patients had abnormalities consistent with the clinical diagnosis. Ten had abnormalities in the brain, three spinal cord lesions, and three showed evidence of optic neuritis. CT was normal in 6 of the 7 patients in which it was performed. |
8041442 | Cerebrospinal fluid flow and production in patients with normal pressure hydrocephalus studied by MRI. | An interleaved velocity-sensitised fast low-angle shot pulse sequence was used to study cerebrospinal fluid (CSF) flow in the cerebral aqueduct, and supratentorial CSF production in 9 patients with normal pressure hydrocephalus (NPH) and 9 healthy volunteers. The peak aqueduct CSF flow, both caudal and rostral, was significantly increased in patients with NPH. No significant difference in the supratentorial CSF production rate was found between patients (mean 0.60 +/- 0.59 ml/min) and healthy volunteers (mean 0.68 +/- 0.31 ml/min). Our method may be useful for investigation and monitoring of patients with NPH before and after ventriculoperitoneal shunt operations. |
8041441 | Magnetic resonance angiography in meningovascular syphilis. | Meningovascular neurosyphilis (MN) is an unusual cause of stroke in young adults. The clinical manifestations include prodromal symptoms weeks or months before definitive stroke. The diagnosis is based on clinical findings and examination of the serum and cerebrospinal fluid. We report a case of MN with basilar artery irregularities demonstrated by magnetic resonance angiography. |
8041440 | Detection of intracranial aneurysms by three-dimensional time-of-flight magnetic resonance angiography. | The purpose of this study was to investigate the reliability of magnetic resonance angiography (MRA) for detection of intracranial aneurysms. Ninety-six consecutive patients who underwent both MRA using the three-dimensional time-of-flight technique (3D TOF) with the rephase/dephase subtraction method and conventional angiography were reviewed. MRA showed 22 aneurysms in 19 patients, and conventional angiography 28 aneurysms in 23 patients. The sensitivity of MRA was thus 79% for aneurysms in 83% of patients. MRA showed no aneurysm in 67 of 73 patients without aneurysms; its specificity was therefore 92%. The 6 false positive interpretations were suspected internal carotid artery aneurysms. |
8041439 | Magnetic resonance angiography and selective angiography following extra-intracranial bypass operations. | Magnetic resonance angiography (MRA) was compared with conventional angiography in 14 patients following extra-intracranial arterial anastomosis. In 13 patients the bypass was shown by MRA and confirmed by conventional angiography. In five of these, the anastomosed vessels, in particular the superficial temporal artery, was of the same calibre or smaller than the same vessels on the contralateral, healthy side. In one patient no anastomosis could be shown by MRA, and occlusion of the bypass was confirmed by conventional angiography. Absence of dilatation of the anastomotic vessels may indicate insufficient bypass function due to stenosis or an incorrect indication for surgery. |
8041438 | Magnetic resonance angiography (MRA) of the circle of Willis: a prospective comparison with conventional angiography in 54 subjects. | We prospectively correlated the findings of magnetic resonance angiography (MRA) with those of transfemoral four-vessel angiography in 54 patients to investigate the direction of flow within the circle of Willis. Our primary goal was to assess the direction of flow using the size of the vessel and signal intensity, without saturation techniques. Analysis of the circle of Willis, especially the communicating arteries, was performed double-blind by two groups of two radiologists. Three types of arteries were identified: high flow or cross-cerebral circulation, patent and nonvisualised arteries. Cerebral angiography was the standard for comparison between the two methods. MRA did not reveal any arteries invisible on angiography, thus providing a specificity of 100%. The sensitivity of MRA was 89.2% for the anterior and 81.3% for the posterior communicating arteries, and 100% for the anterior, middle and posterior cerebral arteries. MRA was shown to be a useful technique for the assessment of patency of the circle of Willis. |
8041437 | Use of magnetisation transfer contrast to improve cerebral 3D MR angiography. | To improve 3D-time of flight (3D-TOF) magnetic resonance angiography, we used magnetisation transfer (MT) to increase the contrast between flowing blood and stationary tissues. With a 1.5 KHz off-resonance radio-frequency MT applied for 16 ms at a maximum power within specific absorption rate (SAR) limits, a 37% decrease in the signal of white matter was obtained, whereas the signal from flowing blood decreased by only 8%. An improvement in maximum intensity projection (MIP) image quality was obtained all MT-3DTOF studies on seven volunteers using progressively more powerful MT pulses. Routine clinical use of MT-3DTOF appears promising and can be achieved at any strength field. |
8041436 | Computer-assisted 3D reconstruction of the terminal branches of the cerebral arteries. II. Middle cerebral artery. | We present a three-dimensional anatomical computer model of the terminal branches of the middle cerebral artery, acquired from equidistant serial anatomical slices of three brains. The reconstructions provide a clear picture from all angles of the complicated course of the terminal branches of the cerebral arteries, which can help to identify them on conventional angiography and magnetic resonance angiography. The arteries can also be matched with CT, MR or PET images to indicate the areas of extension of individual branches, allowing neuromorphological and functional correlations. |
8041435 | Computer-assisted 3D reconstruction of the terminal branches of the cerebral arteries. I. Anterior cerebral artery. | We present a three-dimensional anatomical computer model of the terminal branches of the anterior cerebral artery, acquired from equidistant serial anatomical slices of three brains. The reconstructions provide a clear picture from all angles of the complicated course of the terminal branches of the cerebral arteries, which can help to identify them on conventional and magnetic resonance angiography. Our rendition of the cerebral arteries can also be matched with CT, MR or PET images to indicate the areas of extension of individual branches, allowing neuromorphological and functional correlations. |
8041419 | Testing reckless drivers for cocaine and marijuana. | Driving under the influence of intoxicating drugs other than alcohol may be an important cause of traffic injuries. We used a rapid urine test to identify reckless drivers who were under the influence of cocaine or marijuana. We conducted a consecutive-sample study in Memphis, Tennessee, in the summer of 1993. Subjects arrested for reckless driving who were not apparently impaired by alcohol (did not have an odor of alcohol, tested negative on breath analysis, or both) were tested for cocaine and marijuana at the scene of arrest. The results of the drug tests were compared with clinical evaluations of intoxication made at the scene by a police officer. A total of 175 subjects were stopped for reckless driving, and 150 (86 percent) submitted urine samples for drug testing at the scene of arrest. Eighty-eight of the 150 (59 percent) tested positive: 20 (13 percent) for cocaine, 50 (33 percent) for marijuana, and 18 (12 percent) for both drugs. Ninety-four of the 150 tested drivers were clinically considered to be intoxicated, and 80 of them (85 percent) tested positive for cocaine or marijuana. The intoxicated drivers had a broad range of affects and appearances. Nearly half the drivers intoxicated with cocaine performed normally on standard sobriety tests. Over half of the reckless drivers who were not intoxicated with alcohol were found to be intoxicated with other drugs. Toxicologic testing at the scene is a practical means of identifying drivers under the influence of drugs and is a useful adjunct to standard behavioral sobriety testing. |
8041418 | The risk of dying in alcohol-related automobile crashes among habitual drunk drivers. | Reports suggest that people who drive while intoxicated by alcohol may do so repeatedly. We hypothesized that persons arrested for driving while impaired might be at increased risk for death in an alcohol-related motor vehicle crash. To evaluate this possibility, we studied the deaths of drivers in alcohol-related motor vehicle accidents in North Carolina over a 10-year period. We compared drivers who died in motor vehicle crashes from 1980 through 1989 and who had blood alcohol concentrations of at least 20 mg per deciliter (4.3 mmol per liter), referred to as the case drivers, with those who died in crashes but had blood alcohol concentrations below 20 mg per deciliter, referred to as the control drivers. We identified case drivers and control drivers through the state Medical Examiner System. We then searched North Carolina driver-history files for the five years before each death to identify arrests for driving while impaired. We linked a total of 1646 case drivers and 1474 control drivers to their driver-history files. Case drivers were more likely than control drivers to have been arrested for driving while impaired (26 percent vs. 3 percent). After we controlled for potential confounding variables, case drivers 21 to 34 years of age were 4.3 times more likely (95 percent confidence interval, 2.7 to 6.8) than control drivers to have been arrested for driving while impaired; case drivers 35 years of age or older were 11.7 times more likely (95 percent confidence interval, 6.8 to 20.1). The strength of the association appeared to increase with the number of prior arrests. Case drivers were also more likely than the general population of currently licensed drivers to have been arrested. Arrests for driving while impaired substantially increase the risk of eventual death in an alcohol-related crash. Aggressive intervention in the cases of people arrested for driving while impaired may decrease the likelihood of a future fatal alcohol-related crash. |
8041415 | Improving adjuvant therapy for rectal cancer by combining protracted-infusion fluorouracil with radiation therapy after curative surgery. | The combination of radiation therapy and chemotherapy with fluorouracil plus semustine after surgery has been established as an effective approach to decreasing the risk of tumor relapse and improving survival in patients with rectal cancer who are at high risk for relapse or death. We sought to determine whether the efficacy of chemotherapy could be improved by administering fluorouracil by protracted infusion throughout the duration of radiation therapy and whether the omission of semustine would reduce the toxicity and delayed complications of chemotherapy without decreasing its antitumor efficacy. Six hundred sixty patients with TNM stage II or III rectal cancer received intermittent bolus injections or protracted venous infusions of fluorouracil during postoperative radiation to the pelvis. They also received systemic chemotherapy with semustine plus fluorouracil or with fluorouracil alone in a higher dose, administered before and after the pelvic irradiation. With a median follow-up of 46 months among surviving patients, patients who received a protracted infusion of fluorouracil had a significantly increased time to relapse (P = 0.01) and improved survival (P = 0.005). There was no evidence of a beneficial effect in the patients who received semustine plus fluorouracil. A protracted infusion of fluorouracil during pelvic irradiation improved the effect of combined-treatment postoperative adjuvant therapy in patients with high-risk rectal cancer. Semustine plus fluorouracil was not more effective than a higher dose of systemic fluorouracil given alone. |
8041414 | A randomized comparison of coronary-stent placement and balloon angioplasty in the treatment of coronary artery disease. Stent Restenosis Study Investigators. | Coronary-stent placement is a new technique in which a balloon-expandable, stainless-steel, slotted tube is implanted at the site of a coronary stenosis. The purpose of this study was to compare the effects of stent placement and standard balloon angioplasty on angiographically detected restenosis and clinical outcomes. We randomly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to standard balloon angioplasty. Coronary angiography was performed at base line, immediately after the procedure, and six months later. The patients who underwent stenting had a higher rate of procedural success than those who underwent standard balloon angioplasty (96.1 percent vs. 89.6 percent, P = 0.011), a larger immediate increase in the diameter of the lumen (1.72 +/- 0.46 vs. 1.23 +/- 0.48 mm, P < 0.001), and a larger luminal diameter immediately after the procedure (2.49 +/- 0.43 vs. 1.99 +/- 0.47 mm, P < 0.001). At six months, the patients with stented lesions continued to have a larger luminal diameter (1.74 +/- 0.60 vs. 1.56 +/- 0.65 mm, P = 0.007) and a lower rate of restenosis (31.6 percent vs. 42.1 percent, P = 0.046) than those treated with balloon angioplasty. There were no coronary events (death; myocardial infarction; coronary-artery bypass surgery; vessel closure, including stent thrombosis; or repeated angioplasty) in 80.5 percent of the patients in the stent group and 76.2 percent of those in the angioplasty group (P = 0.16). Revascularization of the original target lesion because of recurrent myocardial ischemia was performed less frequently in the stent group than in the angioplasty group (10.2 percent vs. 15.4 percent, P = 0.06). In selected patients, placement of an intracoronary stent, as compared with balloon angioplasty, results in an improved rate of procedural success, a lower rate of angiographically detected restenosis, a similar rate of clinical events after six months, and a less frequent need for revascularization of the original coronary lesion. |
8041413 | A comparison of balloon-expandable-stent implantation with balloon angioplasty in patients with coronary artery disease. Benestent Study Group. | Balloon-expandable coronary-artery stents were developed to prevent coronary restenosis after coronary angioplasty. These devices hold coronary vessels open at sites that have been dilated. However, it is unknown whether stenting improves long-term angiographic and clinical outcomes as compared with standard balloon angioplasty. A total of 520 patients with stable angina and a single coronary-artery lesion were randomly assigned to either stent implantation (262 patients) or standard balloon angioplasty (258 patients). The primary clinical end points were death, the occurrence of a cerebrovascular accident, myocardial infarction, the need for coronary-artery bypass surgery, or a second percutaneous intervention involving the previously treated lesion, either at the time of the initial procedure or during the subsequent seven months. The primary angiographic end point was the minimal luminal diameter at follow-up, as determined by quantitative coronary angiography. After exclusions, 52 patients in the stent group (20 percent) and 76 patients in the angioplasty group (30 percent) reached a primary clinical end point (relative risk, 0.68; 95 percent confidence interval, 0.50 to 0.92; P = 0.02). The difference in clinical-event rates was explained mainly by a reduced need for a second coronary angioplasty in the stent group (relative risk, 0.58; 95 percent confidence interval, 0.40 to 0.85; P = 0.005). The mean (+/- SD) minimal luminal diameters immediately after the procedure were 2.48 +/- 0.39 mm in the stent group and 2.05 +/- 0.33 mm in the angioplasty group; at follow-up, the diameters were 1.82 +/- 0.64 mm in the stent group and 1.73 +/- 0.55 mm in the angioplasty group (P = 0.09), which correspond to rates of restenosis (diameter of stenosis, > or = 50 percent) of 22 and 32 percent, respectively (P = 0.02). Peripheral vascular complications necessitating surgery, blood transfusion, or both were more frequent after stenting than after balloon angioplasty (13.5 vs. 3.1 percent, P < 0.001). The mean hospital stay was significantly longer in the stent group than in the angioplasty group (8.5 vs. 3.1 days, P < 0.001). Over seven months of follow-up, the clinical and angiographic outcomes were better in patients who received a stent than in those who received standard coronary angioplasty. However, this benefit was achieved at the cost of a significantly higher risk of vascular complications at the access site and a longer hospital stay. |
8041412 | Guidelines for ethical behavior relating to clinical practice issues in electrodiagnostic medicine. American Association of Electrodiagnostic Medicine. | In 1993, the American Association of Electrodiagnostic Medicine formed an Ethics and Peer Review Committee in concert with a renewed initiative by organized medicine to emphasize ethical standards. Guidelines for ethical behavior relating to clinical practice issues in electrodiagnostic medicine were developed to formalize the standards of professional behavior for electrodiagnostic medical consultants and were approved by the AAEM Board of Directors in April 1994. The guidelines are modeled after the Code of Professional Conduct of the American Academy of Neurology and are consistent with the Guidelines in Electrodiagnostic Medicine of the American Association of Electrodiagnostic Medicine and Principles of Medical Ethics as adopted by the American Medical Association. The Guidelines may provide grounds for disciplinary action under Article X of the AAEM Bylaws. |
8041404 | Intestinal pseudo-obstruction in adult spinal muscular atrophy. | A 42-year-old woman with negative family history had the insidious onset of weakness in her lower extremities 8 years before, in 1983. The disorder slowly progressed to include cramps and muscle twitches. The diagnosis of adult spinal muscular atrophy (SMA) was made when electromyography showed large rapidly firing motor unit-potentials, positive waves, and fibrillation potentials, and when muscle biopsy of the quadriceps revealed severe alterations consistent with neurogenic atrophy. The patient also had severe chronic constipation for many years. More recently she had developed unremitting diarrhea. Gastrointestinal studies showed no evidence of peristaltic contractions in the rectum, delayed gastric emptying, and abnormal jejunal manometry with altered propagation of the migrating myoelectrical complex. |
8041403 | Ekbom's syndrome: lipomas, ataxia, and neuropathy with MERRF. | A 66-year-old woman with hereditary deafness and multiple symmetric lipomas presented with ataxia, slight myopathy, and neuropathy. Molecular genetic analysis of mitochondrial DNA revealed the adenine to guanine transition at position 8344 in the tRNA gene for lysine that has been associated with the myoclonic epilepsy and ragged red fiber (MERRF) syndrome. The deafness was transmitted by the patient's father and may have been an unrelated autosomal defect rather than a paternally transmitted mitochondrial point mutation. |
8041402 | M/RMS: an EMG method for quantifying upper motoneuron and functional weakness. | A new method for quantifying upper motoneuron (UMN) weakness using standard EMG equipment is presented and compared to the twitch occlusion method. Control subjects and patients with stroke, spinal cord injury (SCI), and peripheral nerve injury (PNI) were evaluated. Force, EMG, and twitch force from nerve electrical stimulation were recorded during isometric contractions of the biceps and triceps. Ratios of the elicited CMAP amplitude (M)/voluntary-root-mean-square EMG activity (RMS) and of the voluntary contraction twitch force (Ti)/the resting twitch force (Tmax) were the two measures of UMN weakness studied. Both ratios are linearly correlated with force for controls, log M/RMS (r = 0.96) and Ti/Tmax (r = 0.86). Log M/RMS ratio was abnormally high (> mean + 2 SD; i.e., > 1.09) for weak muscles affected by stroke and incomplete SCI, but was normal in muscles weakened by PNI. An elevated M/RMS ratio, may aid in quantification of deficient supraspinal activation from UMN or functional weakness. |
8041401 | Aberrant reinnervation following hypoglossal nerve damage. | Hypoglossal nerve damage is a known complication of carotid endarterectomy, occurring in approximately 5% of endarterectomies. The vast majority of these patients recover without functional disability from this injury even if the tongue remains hemiplegic. We report 2 patients who suffered hypoglossal nerve section during neck surgery. Although they were initially mildly symptomatic, they developed increasingly severe dysarthria and dysphagia beginning 4 months after surgery. EMG revealed abnormal coactivation of the genioglossus and styloglossus muscles on the affected side, suggesting aberrant reinnervation. Aberrant reinnervation is a well-known complication of facial nerve injury, but has not been previously recognized in hypoglossal nerve injury. Like the face, the tongue is composed of many muscles that must perform complex movements. Normally, injury to one hypoglossal nerve causes little or no disability, but when aberrant reinnervation occurs, the tongue no longer moves in a coordinated manner, and significant dysarthria ensues. |
8041400 | Skeletal muscle involvement in tropical spastic paraparesis/HTLV-1-associated myelopathy. | The frequency of muscle involvement in TSP/HAM is not known, nor is the precise role that HTLV-1 and the diverse cytokines play in the genesis of HTLV-1-associated diseases. In order to better define the frequency and characteristics of the skeletal muscle involvement in TSP/HAM, we studied 11 affected patients. EMG was performed in 9 patients and muscle biopsy was performed in all 11. Muscle tissue was analyzed using: reverse transcriptase PCR for interleukin-1 in 8; PCR for HTLV-1 proviral DNA in 5; and electron microscopy for viral particles in 3. We found pathologic alterations in all 11 patients. Four patients (36%) had a neurogenic process, while a primary muscle involvement was observed in the rest (64%). Four patients (36%) had polymyositis, and 3 (27%) had a noninflammatory myopathy. Muscle weakness in the upper limbs was significantly associated with inflammation in the muscle biopsy. EMG was abnormal in only 2 of 9 patients. Reverse transcriptase PCR did not demonstrate message for interleukin-1 in any sample examined. PCR did identify HTLV-1 proviral DNA in the muscle of 3 patients. Retroviral-like particles were found, by EM, in only one biopsy. HTLV-1 may play an important role in the pathogenesis of the frequent myopathies associated with HAM/TSP. |
8041399 | Clinical, electrophysiological, and myelographic studies of 9 patients with cervical spinal root avulsions: discrepancies between EMG and X-ray findings. | In traumatic brachial plexus injuries a thorough neurological, electrodiagnostic, and radiological examination is essential to determine treatment and prognosis. The most important diagnostic question concerns the presence or absence of a preganglionic nerve root lesion. Electromyography and motor and sensory conduction studies were performed in 17 patients with traumatic plexus injuries who had myelographic evidence of nerve root avulsion; in 8 of these clinical and electrophysiological features confirmed the X-ray findings. However, in 9 cases there was a discrepancy between myelographic and neurophysiological data regarding the actual number and sites of roots avulsed. Thus, in 2 cases myelography showed avulsion of one more root than did conduction studies and EMG; in 2 others, there was discordance as to the specific roots avulsed; in 4 cases fewer nerve roots seem to be avulsed radiologically than predicted clinically, and in 1, none at all, although clinical and electrophysiological data were compatible with avulsion of four roots. In 6 cases recovery showed that avulsions indicated by clinical and electrophysiological considerations could not have occurred. When both EMG and myelography are misleading, surgical exploration should be considered. |
8041398 | Prejunctional regulatory actions of androgens on a hormone sensitive muscle. | The influence of androgens and time course of effects induced by hormone deprivation were examined on the spontaneous transmitter release in the levator ani (LA) muscle of 30-180-day-old male rats. The resting membrane potential (RMP) and miniature endplate potentials (mepps) were recorded intracellularly from LA muscle fibers of intact animals or gonadectomized at different ages. In intact animals, the frequency of mepps increased proportionately to the muscle fiber growth up to 60 days, stabilizing thereafter. Gonadectomy at any age did not affect the RMP, but increased the frequency of mepps by 65% to 140%. The effect was detected after 15 days and was unrelated to the degree of muscle atrophy. Independently of the age of gonadectomy control values of mepp frequency were restored after 90 days, while the accompanying postjunctional changes persisted. These results indicate that androgens exert a prejunctional inhibitory influence on the spontaneous transmitter release in the rat LA muscle. The transient nature of the prejunctional effect induced by hormone deprivation indicates an adjustment of nerve terminals to persistent postjunctional alterations. |
8041397 | Muscle fiber conduction velocity in the diagnosis of familial hypokalemic periodic paralysis--invasive versus surface determination. | Muscle fiber conduction velocity (MFCV) in the brachial biceps muscle was determined in a large family of patients with hypokalemic periodic paralysis (HOPP) by both a surface and an invasive method. Other surface EMG parameters and the muscle force were also determined. Both the surface and the invasive method showed a significantly lower mean MFCV in the proven gene carriers but only the invasive method showed a lower MFCV in all proven carriers. It can be concluded that MFCV determination is a reliable method to detect the membrane defect in HOPP carriers and that the invasive method is not only easy to perform, but also more sensitive. The muscle force and the integrated EMG at maximal voluntary contraction were lower in the carrier group. A positive correlation between the surface MFCV and the neuromuscular efficiency (the quotient of force and integrated EMG) was found in the controls but not in the HOPP carriers. Since type II fibers have a higher neuromuscular efficiency, this suggests a preferential involvement of type II fibers in HOPP. |
8041396 | Electrical myotonia of rabbit skeletal muscles by HMG-CoA reductase inhibitors. | HMG-CoA reductase (HCR) inhibitors are effective cholesterol-lowering agents in the treatment of hypercholesterolemia. Using intracellular microelectrodes, we studied the pathomechanism of myotonia experimentally induced in rabbits by HCR inhibitors, simvastatin, and pravastatin. The external intercostal muscle of rabbits showed some electrophysiologic characteristics of myotonia including repetitive firing after administration of simvastatin (50 mg/kg per day, for 4 weeks). The relative chloride conductance, though reduced in both, was more affected in simvastatin-administered muscles. In normal muscles perfused with a solution containing the inhibitors, both simvastatin and pravastatin produced membrane hyperexcitability with repetitive firing similar to that seen in simvastatin-administered rabbits. The minimum concentrations required to cause repetitive firing was 0.3 mg/L for simvastatin and 30 mg/L for pravastatin. These results indicate that HCR inhibitors induce some characteristics of myotonia by blocking the chloride channel in the muscle membrane. |
8041395 | Motor unit number estimates based on the automated analysis of F-responses. | An automated technique for estimating the number of motor units based on single motor unit action potentials in the F-response is described. The average surface detected motor unit action potential (S-MUAP) was calculated from the datapoint-by-datapoint average of a sample of S-MUAPs automatically selected from a population of F-responses. The technique was applied to the thenar muscles of young (n = 18, aged 31 +/- 11 years) and older (n = 15, aged 68 +/- 3) subjects. Motor unit number estimates based on the automated selection of S-MUAPs from the F-responses compared well with those derived using a computer-assisted manual method for selecting S-MUAPs from the F-response (automated 245 +/- 105 vs. manual 241 +/- 100, r = 0.93) and were similar to estimates obtained using multiple point stimulation (219 +/- 77). The advantages of the automated technique for collecting S-MUAPs from the F-response include the ready tolerance of the technique by subjects, the minimal amount of operator interaction required, and the additional information relating to the conduction velocities and latencies of single motor axons. |
8041394 | Limb girdle muscular dystrophy: weakness and disease duration as predictors of functional impairment. | This cross-sectional study compared progressive weakness to functional disability in 20 patients with limb girdle muscular dystrophy. Weakness (assessed by manual muscle testing) determined disability (assessed by functional grades, timed functional tests, and an activities of daily living scale). For any functional grade the degree of weakness varied between patients. Yet, at a certain "threshold" weakness the functional level predictably deteriorated. Change in functional grade did not reflect a parallel increase in weakness nor disease progression. Functional "milestones" were reached at varying durations of disease. Only guidelines were offered to individual patients as to the time course of progression in disability. Serial timed tests should be a sensitive, objective method to follow the rate of disease progression. Timely referral of patients to establish physical needs should delay functional deterioration and minimize handicap despite progressive weakness. |
8041393 | Physiological properties of single thenar motor units in the F-response of younger and older adults. | The purpose of this study was to characterize the properties of single thenar motor units in the F-response of healthy younger (n = 15; age 33 +/- 11 years) and older subjects (n = 15; age 68 +/- 3 years). Trains of 300 stimuli at intensities evoking M-potentials 10%, 20%, and 30% of the peak-to-peak amplitude of the maximum M-potential, were delivered to the median nerve. In the young, observed firing probabilities of surface-detected motor unit action potentials (S-MUAPs) extracted from the F-response ranged from less than 1-10%, the S-MUAPs varied in size from 0.015% to 5.3% of the maximum M-potential negative peak area, and they were similar in size to the population of S-MUAPs collected by multiple point stimulation of the median nerve. The percentage difference between the slowest and fastest conducting fibers for individual subjects ranged from 8% to 20%, which translated to conduction velocities (CVs) of 48-68 m.s-1 (mean 59 +/- 4). The preceding were all independent of stimulus intensity. The S-MUAP sizes were significantly larger in older subjects (39%), and the range and distribution of motor unit CVs (38-61 m.s-1; mean 52 +/- 3) were markedly shifted to reflect a slower population of motor fibers. These findings suggest that age-related axonal slowing may uniformly affect all median motor fibers. |
8041392 | Potassium and caffeine contractures of mouse muscles before and after fatiguing stimulation. | To assess the impairment of muscle membrane excitation, excitation-contraction (E-C) coupling, and contractility during muscle fatigue, we monitored the contracture responses of resting and fatigued muscles on exposure to high potassium and caffeine. On exposure to 140 mmol/L potassium, mouse extensor digitorum longus (EDL) developed a contracture which was 15.7% of tetanic tension before fatigue and 31.7% after fatigue, while soleus developed 59.4% contracture before and 68.8% after fatigue. Potassium causes contractures by depolarizing the muscle fiber membrane. Hence, membrane excitation is reduced in fatigued EDL and soleus. On exposure to 32 mmol/L caffeine, the contracture was 7.1% in resting EDL, 8.5% in fatigued EDL, 50.1% in resting soleus, and 43.7% in fatigued soleus. On exposure to 1 mmol/L caffeine followed by rapid cooling, the contracture was 3.0% in resting EDL, 3.2% in fatigued EDL, 21.5% in resting soleus, and 10.3% in fatigued soleus. Caffeine causes contracture by releasing Ca++ from the sarcoplasmic reticulum. Our results indicate reduced E-C coupling attributable to reduced membrane excitation in fatigued EDL, and reduced contractility in fatigued soleus. |
8041391 | Reference values of motor unit action potentials obtained with multi-MUAP analysis. | We collected reference values of motor unit action potentials (MUAPs) from healthy deltoid, brachial biceps, first dorsal interosseous, lateral vastus, and anterior tibial muscles in 105 subjects between 15 and 86 years. The MUAPs were recorded with a concentric needle electrode and extracted with a decomposition method we call multi-MUAP analysis. The main goal is to identify and extract MUAPs. Also, the firing pattern of the motor units can be followed. No significant changes with age were found for duration, spike duration, thickness, amplitude, area, size index, or number of phases in all muscles studied. We did not find any influence of gender or height. We found higher amplitudes and shorter durations compared with previous studies. This may be due to a higher contraction level that can be used with a decomposition technique. No right-left side differences were found. The coefficient of variation of the parameters in repeated examinations was small, which implies a good reliability of the measurements. Interexaminer variability of four investigators was not greater than in repeated studies. |
8041390 | Postexercise phosphocreatine resynthesis is slowed in multiple sclerosis. | To determine whether skeletal muscle oxidative metabolism is impaired in multiple sclerosis (MS), phosphorus magnetic resonance spectroscopy was used to measure the rate of intramuscular phosphocreatine (PCr) resynthesis following exercise in MS and controls. Thirteen MS patients underwent intermittent isometric tetanic contractions of the dorsiflexor muscles elicited by stimulation of the peroneal nerve. Eight healthy control subjects performed voluntary isometric exercise of the same muscles. During exercise, there were no differences between groups in the fall of either PCr or pH. However, the half-time (T1/2) of PCr recovery following exercise was significantly longer in MS (2.3 +/- 0.3 min) compared to controls (1.2 +/- 0.1 min, P < 0.02). These data provide evidence of slowed PCr resynthesis following exercise in MS, which indicates impaired oxidative capacity in the skeletal muscle of this group. This finding suggests that intramuscular changes consistent with deconditioning may be important in the altered muscle function of persons with MS. |
8041380 | Leuprolide acetate for exhibitionism in Huntington's disease. | We treated a patient with Huntington's disease and exhibitionism using leuprolide acetate (Lupron Depot, TAP Pharmaceuticals), a gonadotropin-releasing hormone agonist. The result was elimination of his deviant sexual behavior with few side effects. This regimen may be a safe and effective pharmacological treatment of the paraphilias. The occurrence of paraphilias in basal ganglia disorders is reviewed. |
8041379 | Pulmonary embolism: an under-recognized yet frequent cause of death in parkinsonism. | There are very few detailed reports on the cause of death in patients with Parkinson syndrome, and most reports lack postmortem verification. Pulmonary embolism has been reported as an infrequent terminal event. We reviewed the results of 60 complete autopsies performed on patients with Parkinson syndrome personally cared for at our institution. Pulmonary embolism was second only to pneumonia as the most common cause of death overall. |
8041378 | Botulinum toxin in the treatment of dystonic tics. | Botulinum toxin (BTX) injections provide effective treatment for a variety of disorders manifested by inappropriate muscle contractions, but its efficacy in the treatment of tics has not been previously studied. Ten male patients 13-53 years of age who were diagnosed with Tourette's syndrome manifested by disabling focal tics were included in this pilot study. Five patients had frequent blinking and blepharospasm, rendering them "blind," and five patients had severe and painful dystonic tics involving their neck muscles. All 10 patients experienced moderate to marked improvement in the intensity and frequency of tics after BTX injections into the involved muscles. Patients in whom premonitory urges preceded their tics noted marked lessening of these sensory symptoms. The benefit lasted 2-20 weeks after injections. There were no serious complications, except for transient ptosis in two and neck pain, stiffness, or weakness in three patients. BTX injections appear to be safe and effective treatment for patients with focal dystonic tics. The treatment ameliorates not only involuntary movements but also the premonitory sensory component associated with some tics. |
8041377 | Reversible intermittent rhythmic myoclonus with fluoxetine in presumed Pick's disease. | A 61-year-old man with presumed Pick's disease was successfully treated with fluoxetine for pathological affect. Severe intermittent, rhythmically repetitive trains of myoclonus developed suddenly the following year. A dystonic-like component involving the shoulder region and a decrescendo frequency pattern were observed. Myoclonus involved the face, palate, shoulder, neck, upper chest and back, diaphragm, hips, and upper extremities, especially on the right side. Movements were not influenced by postural adjustments, startle, or other stimuli. Movements proved insensitive to benztropine but abated with discontinuation of fluoxetine. Rechallenge with fluoxetine or trazodone evoked the movements, whereas clonazepam and chloral hydrate abolished the movements. The pattern of myoclonus is unlike previous reported cases and may relate to activation of serotonin 5HT1A receptors (possibly supersensitive in Pick's disease) or to hypodopaminergia. Although fluoxetine may be useful as adjunct therapy in dementing disorders, caution may be warranted in its use in Pick's disease. |
8041376 | Reliability of symptom onset assessment in Parkinson's disease. | Test-retest reliability of onset date and type of initial symptoms of Parkinson's disease (PD) was assessed in 45 patients with PD who were drawn from a community-dwelling cohort in New York City. Patients were the sole information providers on both rating occasions. Reliability of symptom-onset data was found to be high, even when the interval between test and retest was up to 3 years and when the information was elicited by different neurologists. However, these patients were less consistent about the type of early symptoms. When interpreting their own disease history, patients with PD may attach more importance to when their disease began than to how it began. |
8041375 | Is cranial computerized tomography useful in the diagnosis of multiple system atrophy? | Cranial computer tomographic (CT) images of 33 patients with multiple system atrophy (MSA) and of 40 age-matched controls were blindly analyzed by two neuroradiologists. All patients had autonomic dysfunction, all but one had parkinsonism, and 13 had cerebellar signs. The scans were judged entirely normal in 21%. Moderate or severe infratentorial atrophy was found in 42%. Cerebellar atrophy was present in 39%, and pontine atrophy was present in 18%. Of the 13 patients with cerebellar signs, only eight had cerebellar atrophy. Of the 20 patients without cerebellar signs, five had cerebellar atrophy. Supratentorial involvement was much less common and less severe. Thus, CT demonstrated system involvement that was not evident clinically in five of 33 cases (15%). However, in all five the clinical diagnosis was already evident from the presence of both autonomic and pyramidal signs in addition to parkinsonism. We conclude that CT imaging is of limited diagnostic use in individual patients with MSA. |
8041374 | Familial hemifacial spasm. | Two brothers developed hemifacial spasm at 63 and 70 years of age. Spasms occurred on the left and right sides of the face, respectively. Computed tomography scan and magnetic resonance imaging failed to show any abnormality. In addition, a third sibling reported a history of a peripheral facial palsy, which remitted spontaneously without sequelae. This is the fourth description of familial hemifacial spasms. This family is unique in that hemifacial spasm presented on different sides in the two brothers, and involvement was limited to one generation. Age at onset was later than for other familial cases and similar to sporadic cases. |
8041373 | Spinal myoclonus resembling belly dance. | A 63-year-old man presented with an 11-month history of progressive myoclonus in the right abdominal wall. Administration of clonazepam reduced the frequency and amplitude. When the therapy was discontinued, the frequency and amplitude of the myoclonus increased, and synchronous and weak myoclonus also was observed in the left abdomen. The trunk was twisted just after the appearance of the abdominal myoclonus associated with myoclonic jerks spreading from the rostral to caudal paraspinal muscles. Later in the clinical course, the myoclonus became stimulus sensitive and was induced by tendon tap given anywhere on the body, with the latency ranging from 50 to 150 ms irrespective of the sites of tapping. Myoclonus seen in the abdominal wall was segmental and considered to be of spinal origin. The reflex myoclonus had a 150-ms refractory period. It can be postulated that increased excitability of anterior horn cells at a certain segment might make a spino-bulbo-spinal reflex manifest at the corresponding segment. This myoclonus is considered to be a new form of spinal reflex myoclonus, because the abdominal myoclonic jerk seems to trigger another myoclonic jerk involving the paraspinal muscles. |
8041372 | Adductor laryngeal breathing dystonia in a patient with lubag (X-linked dystonia-Parkinsonism syndrome). | We report a patient with Lubag (X-linked dystonia-parkinsonism) who presented with severe respiratory stridor from adductor laryngeal breathing dystonia. Emergency tracheostomy was necessary, and subsequent laryngeal injection with botulinum toxin led to worsening aspiration. Botulinum toxin injection for severe lingual dystonia was successful. |
8041370 | The neuropathological features of neuroacanthocytosis. | In this article we describe the neuropathological changes in three patients with neuroacanthocytosis and review the neuropathology of the other eight cases reported in the literature. Macroscopically the brains showed enlargement of the lateral ventricles, especially the frontal horns. The most severely and consistently affected brain areas were the caudate nucleus and putamen, which were atrophic and showed by light microscopy marked neuronal loss and gliosis. Small and medium-sized striatal neurons were particularly depleted. The globus pallidus was almost as severely involved as the striatum. In some cases the thalamus, substantia nigra, and anterior horns of the spinal cord showed pathology, mainly neuronal loss and mild gliosis. Brain areas with no pathology included the subthalamic nucleus, cerebral cortex, cerebellum, pons, and medulla. The preservation of these areas may help in the neuropathological distinction of neuroacanthocytosis from Huntington's disease. |
8041371 | Analysis of repetitive and nonrepetitive sequential arm movements in patients with Parkinson's disease. | We examined the motor performance of Parkinson's disease patients and normal subjects during nonrepetitive and repetitive sequential tasks. Parkinson's disease patients took longer than normal subjects to complete the nonrepetitive task, the sequential drawing of a pentagon. In patients, movement times lengthened as the sequence neared completion. The amount of lengthening was similar in nonrepetitive and repetitive tasks (sequential alternating drawing of each side of the pentagon). In parkinsonian patients the slowing at the end of the sequential tasks does not appear to be influenced by whether the sequential task involves nonrepetitive or repetitive movements. |
8041369 | Autosomal-dominant dentatorubropallidoluysian atrophy in the United Kingdom. | Dentatorubropallidoluysian atrophy (DRPLA) has been described chiefly in Japan and appears to be rare in Europe. It is of autosomal dominant inheritance. We report the first British family with DRPLA, which contains four affected individuals in two generations. The diagnosis was made at autopsy in one case. The age of onset of symptoms ranged from 15 to 38 years, and clinical features included ataxia, dementia, chorea, and dystonia; three patients had generalized seizures. The three living patients resemble those with early Huntington's disease clinically. Three main phenotypes of DRPLA have been proposed: an ataxo-choreoathetoid type, a pseudo-Huntington type, and a myoclonic epilepsy type. The variation in clinical presentation in our family demonstrates the difficulty in applying such classifications to this and other dominantly inherited disorders with phenotypic variation. DRPLA is likely to be confused with Huntington's disease in European families. |
8041368 | Molecular characterization of thirteen gyrA mutations conferring nalidixic acid resistance in Bacillus subtilis. | We isolated 607 independent nalidixic acid-resistant mutants from Bacillus subtilis. A 163 bp DNA segment from a 5' portion of the gyrA gene was amplified from the DNA of each mutant strain. After heat denaturation, the product was subjected to gel electrophoresis to detect conformational polymorphism of single-strand DNA (PCR-SSCP analysis). Mobility patterns of the two DNA strands from all the mutant strains examined differed from those of the parental wild-type strains. The patterns were classified into 13 types, and the DNA sequence of each type was determined. A unique sequence alteration was found in mutants belonging to each of the 13 types, defining 13 gyrA alleles. Eight were single base pair substitutions, four were substitutions of two consecutive base pairs and one was a substitution of three consecutive base pairs. Only three amino acid residues (Ser-84, Ala-85, and Glu-88) were altered in the deduced amino acid sequences of the mutated genes. We conclude that molecular typing based on the PCR-SSCP method is a powerful technique for the exhaustive identification of allelic variants among mutants selected for a phenotypic trait. |
8041367 | Cerulenin-resistant mutants of Saccharomyces cerevisiae with an altered fatty acid synthase gene. | Cerulenin, an antifungal antibiotic produced by Cephalosporium caerulens, is a potent inhibitor of fatty acid synthase in various organisms, including Saccharomyces cerevisiae. The antibiotic inhibits the enzyme by binding covalently to the active center cysteine of the condensing enzyme domain. We isolated 12 cerulenin-resistant mutants of S. cerevisiae following treatment with ethyl methanesulfonate. The mechanism of cerulenin resistance in one of the mutants, KNCR-1, was studied. Growth of the mutant was over 20 times more resistant to cerulenin than that of the wild-type strain. Tetrad analysis suggested that all mutants mapped at the same locus, FAS2, the gene encoding the alpha subunit of the fatty acid synthase. The isolated fatty acid synthase, purified from the mutant KNCR-1, was highly resistant to cerulenin. The cerulenin concentration causing 50% inhibition (IC50) of the enzyme activity was measured to be 400 microM, whereas the IC50 value was 15 microM for the enzyme isolated from the wild-type strain, indicating a 30-fold increase in resistance to cerulenin. The FAS2 gene was cloned from the mutant. Sequence replacement experiments suggested that an 0.8 kb EcoRV-HindIII fragment closely correlated with cerulenin resistance. Sequence analysis of this region revealed that the GGT codon encoding Gly-1257 of the FAS2 gene was altered to AGT in the mutant, resulting in the codon for Ser. Furthermore, a recombinant FAS2 gene, in which the 0.8 Kb EcoRV-HindIII fragment of the wild-type FAS2 gene was replaced with the same region from the mutant, when introduced into FAS2-defective S. cerevisiae complemented the FAS2 phenotype and showed cerulenin resistance.(ABSTRACT TRUNCATED AT 250 WORDS) |
8041366 | Interplasmid transposition of Drosophila hobo elements in non-drosophilid insects. | A modified hobo element from Drosophila melanogaster was introduced into embryos of the housefly, Musca domestica (family Muscidae) and the Queensland fruitfly, Bactrocera tryoni (family Tephritidae) to assess its ability to transpose. Hobo was capable of transposition in these species and transposition products had all of the hallmarks of hobo transposition products recovered from D. melanogaster, including the movement only of sequences precisely delimited by the inverted terminal repeats of hobo, the creation of an 8 bp duplication of the insertion site and an absolute requirement for hobo-encoded transposase. Transposition of hobo into the target gene resulted in a non-random distribution of insertion sites, with 10 of 38 independent insertions into the same nucleotide position. The results indicate that hobo can transpose in heterologous species, further demonstrating the similarity of hobo to Ac (Activator) of Zea mays and Tam3 of Antirrhinum majus. Hobo has excellent potential to act as a gene vector or gene tagging agent in nondrosophilid insects. |
8041365 | The NADH dehydrogenase subunit 7 gene is interrupted by four group II introns in the wheat mitochondrial genome. | We have characterized a wheat mitochondrial gene, designated nad7, capable of encoding a 394-amino acid subunit of the respiratory chain NADH dehydrogenase complex. It contains four introns possessing group II features and their positions differ from those in both the liverwort mitochondrial nad7 pseudogene and the nuclear gene encoding the homologous 49 kDa subunit of complex I in Neurospora. The derived amino acid sequence of the wheat nad7 gene is strongly conserved relative to its nuclear or organellar counterparts in other organisms. C-to-U type RNA editing, which is observed at 32 positions within the coding region of wheat nad7 transcripts, strengthens protein sequence similarity. RNA editing is also predicted to improve base-pairing within the domain V/VI regions of all four introns. |
8041364 | The complete karyotype of Aspergillus niger: the use of introduced electrophoretic mobility variation of chromosomes for gene assignment studies. | A method is described for unambiguous assignment of cloned genes to Aspergillus niger chromosomes by CHEF gel electrophoresis and Southern analysis. All of the eight linkage groups (LGs), with the exception of LG VII, have previously been assigned to specific chromosomal bands in the electrophoretic karyotype of A. niger. Using a LG VII-specific probe (nicB gene of A. niger) we have shown that LG VII corresponds to a chromosome of about 4.1 Mb. Furthermore, genetic localization of three unassigned genes (glaA, aglA and pepA) in strains in which these genes had been replaced by a selectable marker gene led to a revised karyotype for the chromosomes corresponding to LGs VIII and VI. The revised electrophoretic karyotype reveals only 5 distinct bands. The presence of three pairs of equally sized chromosomes precluded assignment of genes to one specific chromosome in the wild-type strain. However, unambiguous chromosome assignment of cloned genes using CHEF-Southern analysis was demonstrated using a set of A. niger strains with introduced chromosomal size variation. The availability of these tester strains obviates the need to isolate or construct mutant strains for the purpose of chromosome assignment. |
8041362 | Molecular cloning of a cysteine synthase cDNA from Citrullus vulgaris (watermelon) by genetic complementation in an Escherichia coli Cys- auxotroph. | We have isolated cDNA clones encoding cysteine synthase (CSase, EC 4.2.99.8), which catalyzes the terminal step in cysteine biosynthesis, by direct genetic complementation of a Cys- mutation in Escherichia coli with an expression library of Citrullus vulgaris (watermelon) cDNA. The library was constructed from 8-day-old etiolated seedlings of C. vulgaris in the lambda ZAPII vector, converted to a plasmid library by in vivo excision, and then used for transformation of cysteine auxotroph E. coli NK3, which lacks the cysK and cysM loci. The complementing cDNA containing a 560 bp 5'-untranslated region encodes a polypeptide of 325 amino acids of M(r) 34342. The translational product reacted with an antibody raised against CSase A of Spinacia oleracea. CSase and beta-pyrazolealanine synthase activities were demonstrated in vitro in extracts from E. coli cells expressing the cDNA. Genomic DNA blot analysis indicated the presence of a single copy of the gene, designated cysA, in the C. vulgaris genome. RNA blot hybridization indicated constitutive expression of cysA in cotyledons, hypocotyls and radicles of green and etiolated seedlings. These data suggested that this cDNA clone encodes CSase A the homolog of which in spinach is localized in the cytoplasm. The molecular phylogenetic tree of the amino acid sequences of CSases from plants and bacteria suggested that there are three families in the CSase superfamily; the plant CSase A family, the plant CSase B family and the bacterial CSase family. The proteins in the plant CSase A family are the most conserved relative to the ancestral CSase protein. |
8041363 | RNA editing of tRNA(Phe) and tRNA(Cys) in mitochondria of Oenothera berteriana is initiated in precursor molecules. | We have analyzed the role of RNA editing in the correction of mismatched base pairs in tRNA secondary structures in mitochondria of the flowering plant Oenothera berteriana. Comparison of genomic and cDNA sequences from unprocessed primary transcripts of the newly characterized genes for tRNA(Cys), tRNA(Asn) and tRNA(Ile) and the previously described gene for tRNA(Phe) revealed single nucleotide discrepancies in the tRNA(Cys) and tRNA(Phe) sequences. While the change in the anticodon stem of tRNA(Cys) alters a C-T to a T-T mismatch, the nucleotide transition in the tRNA(Phe) restores a conventional T-A Watson-Crick base pair, replacing a C-A mismatch in the acceptor stem. Since both nucleotide alterations are conversions from genomic cytidines to thymidines in the cDNA (uridines in the tRNAs), they are attributed to RNA editing, which is observed in nearly all mRNAs from plant mitochondria. |
8041361 | Control of ColE2 plasmid replication: regulation of Rep expression by a plasmid-coded antisense RNA. | We isolated and characterized mutants of ColE2 with increased copy number (cop) and those with reduced sensitivity to the wild-type incA gene (inc). Both types of mutations were single-base substitutions in the incA region and simultaneously increased the plasmid copy number and reduced the inhibitory activity of the incA gene on ColE2 DNA replication. Most of the cop mutations also reduced sensitivity to the wild-type incA gene. These mutations were located in the region specifying the large stem-and-loop structures of RNA I and the 5' portion of the Rep mRNA. All these results indicate that RNA I interacts with the Rep mRNA and thereby inhibits expression of the Rep protein at a post-transcriptional step and that this is probably the only mechanism that controls the ColE2 Rep protein expression. It is suggested that only portions of the nucleotides in the loop region are involved in initial (kissing) interaction of these RNAs. The total level of rep gene expression in the host cells appears to be kept constant (at a level characteristic for each cop allele) irrespective of the actual plasmid copy number above a certain level, when rep gene expression is regulated by the incA gene on the same plasmid. These seem to be the basic mechanisms for the replication control of ColE2. |
8041360 | Control of ColE2 plasmid replication: negative regulation of the expression of the plasmid-specified initiator protein, Rep, at a posttranscriptional step. | The incA gene of ColE2 is involved in the copy number control and incompatibility. Two promoters were identified around the incA gene. Transcription of the mRNA for the essential plasmid-coded initiator protein (Rep) mainly starts at a site about 140 bp upstream of the initiation codon of the Rep protein. The second transcript (RNA I) of about 115 nucleotides with two stem-and-loop structures is entirely complementary to the 5' untranslated region of the Rep mRNA. By using translational and transcriptional fusions of the rep gene of ColE2 and the lacZ gene of Escherichia coli, the incA gene product was shown to regulate expression of the rep gene at a posttranscriptional step. The results also suggest that the target of the incA gene product is the 5' untranslated region of the Rep mRNA. Deletion analyses reported here show that a region(s) about 17 to 70 bp upstream of the initiation codon of the Rep protein and another region inside the coding frame are important for efficient production of the Rep protein. This suggests that some additional sequence elements other than the initiation codon and the Shine-Dalgarno region and/or a secondary structure of the Rep mRNA are required for efficient production of the Rep protein. These results show that RNA I is an antisense RNA for the Rep mRNA and imply that it might regulate expression of the rep gene at the initiation step of translation by sequestering such additional sequence elements and/or by disrupting RNA secondary structure. We propose that RNA I represents the incA gene product. |
8041359 | The 42.5 kDa subunit of the NADH: ubiquinone oxidoreductase (complex I) in higher plants is encoded by the mitochondrial nad7 gene. | The N-terminal amino acid sequence of a 42.5 kDa subunit of the NADH: ubiquinone oxidoreductase (complex I) from potato has been determined by direct protein sequencing. The sequence was found to be homologous to that of the nuclear-encoded 49 kDa complex I subunit of bovine and Neurospora mitochondria and to the sequence deduced from the mitochondrial nad7 gene identified in the mitochondrial (mt) DNA of tryp anosomes and the moss Marchantia. An oligonucleotide probe derived from the potato N-terminal protein sequence hybridized only to the plant mtDNA. Immunoprecipitation of in-organello 35S-labelled potato and wheat mitochondrial translation products with an antibody directed against the Neurospora 49 kDa complex I subunit indicates that at least in these plants the NAD7 protein is synthesized within the organelle. Comparisons of genomic, cDNA and protein sequences of the 5' coding region reveal three codons that are changed by RNA-editing and confirm translation of the edited transcripts in plant mitochondria. The NAD7 protein appears to undergo post-translational processing since the N-terminal methionine residue is absent from the mature mitochondrial protein. |
8041358 | Heterospecific cloning of Arabidopsis thaliana cDNAs by direct complementation of pyrimidine auxotrophic mutants of Saccharomyces cerevisiae. I. Cloning and sequence analysis of two cDNAs catalysing the second, fifth and sixth steps of the de novo pyrimidine biosynthesis pathway. | An Arabidopsis thaliana cDNA library was used to complement Saccharomyces cerevisiae pyrimidine auxotrophic mutants. Mutants in all but one (carbamylphosphate synthetase) of the six steps in the de novo pyrimidine biosynthetic pathway could be complemented. We report here the cloning, sequencing and computer analysis of two cDNAs encoding the aspartate transcarbamylase (ATCase; EC 2.1.3.2) and orotate phosphoribosyltransferase-orotidine-5'-phosphate decarboxylase (OPRTase-OMPdecase; EC 2.4.2.10, EC 4.1.1.23) enzymes. These results confirm the presence in A. thaliana of a bifunctional gene whose product catalyses the last two steps of the pyrimidine biosynthetic pathway, as previously suggested by biochemical studies. The ATCase encoding cDNA sequence (PYRB gene) shows an open reading frame (ORF) of 1173 bp coding for 390 amino acids. The cDNA encoding OPRTase-OMPdecase (PYRE-F gene) shows an ORF of 1431 bp coding for 476 amino acids. Computer analysis of the deduced amino acid sequences of both cDNAs shows the expected high similarity with the ATCase, ornithine transcarbamylase (OTCase; EC 2.1.3.3), OPRTase and OMPdecase families. This heterospecific cloning approach increases our understanding of the genetic organization and interspecific functional conservation of the pyrimidine biosynthetic pathway and underlines its usefulness as a model for evolutionary studies. |
8041357 | The rolC promoter of Agrobacterium rhizogenes Ri plasmid is activated by sucrose in transgenic tobacco plants. | The 5'-upstream region of the rolC gene of the Ri plasmid is expressed specifically in phloem cells of transgenic higher plants. In this study, we demonstrated that the rolC promoter is activated by sucrose in phloem cells of transgenic tobacco seedlings bearing rolC promoter-uidA chimeric fusion gene. Since the rolC promoter is not activated by sorbitol, sucrose metabolism rather than osmotic pressure exerted by the disaccharide may be responsible for induction. Thus, experiments using 5'-upstream deletion mutants, internal deletion mutants, and chimeric constructs with a heterologous promoter (-90 region of the cauliflower mosaic virus 35S promoter) were conducted to define the region of the rolC promoter involved in sucrose activation. The results indicated that a cis-acting sucrose responsive region of the rolC promoter is located between -135 and -94 bp with respect to the transcription initiation site. In phloem cells, high concentrations of sucrose are encountered owing to ongoing translocation of photosynthates from source to sink tissues. Therefore, sucrose as a signal molecule may regulate the phloem-specific expression of the rolC promoter. |
8041356 | Sequence variability of the 40-kDa outer membrane proteins of Fusobacterium nucleatum strains and a model for the topology of the proteins. | The complete nucleotide sequences of the fomA genes encoding the 40-kDa outer membrane proteins (OMPs) of strains ATCC 10953 and ATCC 25586 of Fusobacterium nucleatum were determined using the genomic DNA, or DNA fragments ligated into a vector plasmid, as template in a polymerase chain reaction. The deduced amino acid sequences of these two proteins were aligned with the amino acid sequence of the corresponding protein of F. nucleatum strain Fev1 and examined for conserved/variable polypeptide segments. A model for the topology of the 40-kDa OMPs is proposed on the basis of this alignment and application of the structural principles derived for OMPs of Escherichia coli. According to this model, sixteen polypeptide segments, which are highly conserved, traverse the outer membrane, thereby creating eight external loops, most of which are highly variable. |
8041355 | Nitrate reductase of the ascomycetous fungus, Leptosphaeria maculans: gene sequence and chromosomal location. | The nitrate reductase (niaD) gene was isolated from the phytopathogenic loculoascomycete Leptosphaeria maculans by screening a genomic DNA library with the Aspergillus nidulans niaD gene. The L. maculans niaD gene is the first protein-encoding gene characterised from this fungus. It encodes a predicted protein of 893 amino acids and contains four putative introns at positions in the gene equivalent to those of four of the six introns in the A. nidulans niaD gene. Mutants defective in niaD and molybdenum cofactor gene(s) of L. maculans have been isolated. Transformation of a L. maculans niaD mutant with a 3.8 kb SacII fragment containing the L. maculans niaD gene restored wild-type growth on nitrate as a sole nitrogen source. The niaD gene is present as a single copy on a chromosome which ranges in size from 2.6 to 2.8 Mb between the different L. maculans isolates examined. |
8041353 | Personal watercraft injuries: experience at a community hospital. | A 16-month retrospective review was performed of patients brought to Lake of the Ozarks General Hospital Emergency Department for treatment of injuries suffered in personal watercraft accidents. Fourteen of 37 patients showed clinical and radiographic evidence of fractures or internal injuries. Personal watercraft accidents are a significant cause of morbidity in a lake resort community population. |
8041352 | Substance abuse and dependence in physicians: an overview of the effects of alcohol and drug abuse. | Substance abuse and dependence (alcohol and drugs) are behavioral disorders and treatable medical diseases. Early intervention followed by appropriate treatment can often help return physicians to healthy personal and professional lives. Current scientific evidence suggests the prevalence of substance abuse or dependence among the medical profession over a lifetime is approximately 10-15%, slightly in excess of the general population. The initiation of intervention is critical and ultimately may be lifesaving. |
8041350 | Syphilis in Missouri: a continuing problem. | Syphilis has re-emerged as a significant public health problem in the United States and Missouri. Reported cases of primary and secondary (P&S) syphilis and congenital syphilis in Missouri have been increasing since the late 1980s, and a major outbreak of these diseases continues in the St. Louis area. The nature of syphilis combined with certain characteristics of those populations at highest risk of infection can make prevention and control difficult. Achieving success requires the cooperative efforts of practicing physicians and public health professionals. |
8041349 | Congenital myasthenic syndromes. | The congenital myasthenic syndromes are uncommon but challenging disorders. They can arise from presynaptic defects that reduce quantal size or alter quantal release or from postsynaptic defects that impair quantal efficiency. This article reviews the pathologic mechanisms as well as the clinical and laboratory diagnosis in the syndromes characterized to date. |
8041348 | Diagnosis and treatment of Lambert-Eaton myasthenic syndrome. | Lambert-Eaton myasthenic syndrome is a rare autoimmune neuromuscular and autonomic disease that produces fluctuating muscle weakness, hyporeflexia, and autonomic dysfunction, and often is associated with small-cell lung cancer. The pathophysiology is understood quite well; antibodies to voltage-gated calcium channels in motor and autonomic nerve terminals disrupt calcium influx and reduce acetylcholine release. The diagnosis may be suspected clinically, but must be confirmed with electrophysiologic testing. Initial and then periodic screening for malignancy is essential. Tumors other than small-cell lung cancer occasionally are found. Effective tumor treatment may induce remission. Active disease may respond to agents that enhance neuromuscular transmission or to immunosuppression. Combined therapy frequently is needed and control is often marginal despite this. It is expected that availability of 3,4-DAP will improve significantly the response to treatment in most patients. |
8041347 | Nursing care of the patient with myasthenia gravis. | Nursing priorities for patients with acquired autoimmune myasthenia gravis are reviewed. Three key aspects of care are discussed: assessment of weakness, knowledge of treatments and medications, and understanding the need for patient education and support. The article traces these needs throughout the diagnostic process, during hospitalization, including crisis, and subsequent outpatient care. Advances in treatment and their implications for nursing care are emphasized. |
8041346 | The treatment of patients with myasthenia gravis. | Although there is general agreement among experienced physicians on the usefulness of different treatments for myasthenia gravis (MG), so many variations are possible that in practice, similar patients treated by different physicians rarely are treated the same. Because of these divergent opinions one may read papers in reputable journals that present and propose extremely variable programs for treating MG. Scientific controversies, although stimulating, often result in confusion, especially for less experienced physicians seeking treatment guidelines for their patients. This article offers the authors' opinions on the benefits and limitations of the therapeutic modalities used in MG and their proposals of therapeutic plans for specific situations. |
8041345 | The thymus in myasthenia gravis. | The experimental work discussed here endorses the hypothesis that in the pathogenesis of MG the initial and essential steps take place within the thymus. Most, if not all, thymuses of MG patients contain B cells capable of producing AChR-specific autoantibody along with appropriate stroma elements. This is especially pertinent in hyperplastic thymuses with germinal centers, which characteristically contain cellular complexes formed by AChR-producing MCs and surrounding interdigitating dendritic cells. The source of the myasthenogenic autoantigen is more complex in thymomas. There are data suggesting that thymoma epithelium express a protein that shares certain peptide epitopes with the AChR alpha chain, although there is no further molecular similarity. A unique type of "molecular self mimicry" could be the starter of thymoma-associated MG. |
8041343 | Pathophysiology of myasthenia gravis and Lambert-Eaton syndrome. | The first part of this article delineates the most important structural and functional bases of neuromuscular transmission under normal conditions. Next, the main effects of myasthenic antibodies at the neuromuscular junction are described. The article emphasizes the role of inflammation as a transient phase proceeding the degenerative changes of the neuromuscular junction observed in myasthenia gravis. The article ends with a discussion of the principal molecular and physiologic changes accounting for the impairment of neuromuscular transmission in Lambert-Eaton Myasthenic Syndrome. |
8041344 | The electrodiagnosis of myasthenia gravis and the Lambert-Eaton myasthenic syndrome. | Electrodiagnostic studies are valuable in confirming the diagnosis of a disorder of neuromuscular transmission. They are used to distinguish presynaptic and postsynaptic abnormalities. These studies provide an objective measure of the severity of the illness and may be useful in assessing the response to therapy. This article reviews the electrodiagnostic techniques that are commonly used today and highlights their specificity, sensitivity, and pitfalls. |
8041342 | Acquired myasthenia gravis. Immunopathology. | Much of the remarkable advance in our understanding of the immunopathology of MG relates to the availability of two gifts of nature that permit the ready purification of the antigen, AChR. Immunization of experimental animals with AChR has led to the development of the extremely faithful animal model, EAMG. Analysis of both EAMG and MG has revealed that the effector agents in this autoimmune disease are anti-AChR antibodies, whose production is regulated by anti-AChR CD4+ T cells. The pathogenic effects on neuromuscular transmission are mediated by antibody-induced antigenic modulation of end-plate AChR, end-plate membrane destruction through complement fixation and recruitment of inflammatory cells, and antibody-induced blockade of the function of the remaining AChR molecules. The origin of MG remains unknown. One theory proposes that dysregulation of the thymic control of tolerance plays an important role. An alternative hypothesis is that tolerance is broken as the result of a vigorous immune response directed against an invading microorganism that expresses a molecule that is similar to AChR, so-called molecular mimicry. This "normal" response eventually cross-reacts with self-AChR, resulting in the autoimmune damage. Our current knowledge of MG has suggested a number of possible sites of therapeutic intervention that are under active study. Future information concerning the origin of the disease will likely be useful in the design of more effective treatment for this and other related autoimmune diseases. |
8041341 | The epidemiology of myasthenia gravis. | This review has attempted to show what the patient population with MG really looks like. Generalizations about the manifestations of the disease may not be accurate if they are derived from small numbers of patients. The epidemiologic "big picture" provides a more realistic overview of the disease. There are surprisingly fewer patients with MG than many experienced clinicians expect. This does not diminish the impact of the disease on the individual patient, but it does give a more realistic view of its place among diseases affecting the nervous system. This knowledge can be used to direct the approach to the disease in the future. The fact that the number of patients with the disease is increasing in older age groups is a tribute to the success of treatment strategies during the past 20 years. As a consequence, the typical patient with MG in the future will likely be older and have additional medical problems. The evolution of our treatment in the future will need to take this factor into consideration. Older patients may not tolerate the aggressive immunosuppressive regimens that benefit young patients. Ideally, more targeted types of therapies that suppress a specific immunologic abnormality without imposing the burden of side effects inherent in present treatments will be most beneficial to these patients. |
8041340 | Clinical features of myasthenia gravis. | Myasthenia gravis (MG) is an antibody-mediated muscle disease in which any skeletal muscle can be affected. MG may produce numerous symptoms and signs. To doctors and patients, it may seem like lung disease, stroke, heart disease, or the effects of emotional stress. This article explores the "territory" between MG and diseases of the heart and lungs as well as the other neuromuscular diseases. |
8041339 | The history of myasthenia gravis. | The first case of myasthenia gravis (MG) was described in 1672. Treatment of MG was negligible until Mary Walker's seminal observation in 1934 of improvement with physostigmine and neostigmine injections. Blalock reported the initial success with thymectomy around 1940. Edrophonium was introduced around 1950 and pyridostigmine in the mid-1950s. John Simpson's hypothesis of an autoimmune etiology for MG in 1960 was later proven correct, and subsequent use of immunosuppressive therapy including corticosteroids led to the modern era in management of MG. |
8041326 | [The modelling of dynamic ascariasis infectivity and prevalence in foci of invasion]. | Suggests a simple model for calculation of ascariasis invasion rate in the population living in temperate climate foci, based on a single copro-ovoscopic examination over the entire epidemic season or a certain period. Describes a method for model construction for various epidemic conditions and a computer program realizing this method. The model is applicable for operative assessment of current ascariasis infection rate and for planning preventive measures. |
8041325 | [Cases of quartan malaria in Rostov and Volgograd provinces]. | Presents a retrospective analysis of four-day malaria incidence in the Rostov and Volgograd districts. Describes three cases of local four-day malaria (two recurrences and one new case). Gives recommendations on prevention of the disease dissemination. |
8041324 | [The malaria prevalence in at-risk groups of the native population in Western Africa. 1. Pregnant women]. | A total of 1277 women at various pregnancy terms were examined in field conditions in four West African countries. Malaria infection rate in areas varying in endemicity and the time course of this incidence in various pregnancy terms were studied. Malaria incidence among pregnant women living in areas mesoendemic for the disease was 13.0 to 16.0%, that in hyperendemic areas 36.9 to 42.1%. Increase of malariometric parameters in the second half of pregnancy was noted. The necessity of chemoprophylaxis in meso- and hyperendemic areas was confirmed. The choice of the drug depends on Plasmodium falciparum sensitivity to this drug and drug tolerance by pregnant women. |
8041323 | [The prevalence of cryptosporidiosis among the city population of Russia and Belarus]. | A total of 248 adults (170 with somatic diseases and 78 with the diarrheal syndrome) and 1206 children (323 attending kindergartens, 231 with somatic diseases, and 652 with the diarrheal syndrome), residents of seven towns of Russia and Belarus, were examined for cryptosporidiosis in 1989-1992. The mean infection rate of children and adults with the diarrheal syndrome was 4.8 and 2.7%, respectively, of those with somatic diseases 2.6 and 0% respectively, and of healthy children 1.9%. Children living in the towns of Belarus, localized in the radiation contamination zone, were more frequently infected than children living in other towns. The towns of the European Russia and Belarus should be regarded as stable foci of cryptosporidiosis infection. |
8041319 | [A method for determining tegalid in biological material]. | Conditions were selected for the extraction of tegalid, a new anthelmintic agent. A method for measurement of tegalide in biologic material, making use of high-pressure liquid chromatography, has been developed and experimentally tried. The method was found highly selective, sensitive and accurate and is recommended for experimental and clinical pharmacokinetic studies. |
8041318 | [An attempt at the serological examination of small mammals in a natural focus of tick-borne encephalitis in central Siberia]. | Studies of blood serum samples from Asian mice from a natural focus of tick-borne encephalitis (TBE) in the Krasnoyarsk district, in which agent strains of medium peripheral activity for white mice predominated, in the hemagglutination inhibition test have given negative results. At the same time murine sera were detected with nonspecific inhibitors to TBE virus in low titers (1:10 to 1:20), this being confirmed by enzyme immunoassay. Of the tested in 1988-1991 1047 mice of 11 species the share of sera with nonspecific inhibitors (and, consequently, positive ones) has made up 3.3 +/- 1.9/0.0 for asian mice (6.2 +/- 3.3/0.0 for males and 0.0/0.0 females), 1.4 +/- 1.4/2.8 +/- 2.0 in striped field mice (0.0/0.0 males and 3.2 +/- 3.2/6.4 +/- 4.5 females), and 0.5 +/- 0.3/5.7 +/- 1.0 in red-backed mice (0.3 +/- 0.3/6.3 +/- 1.4 males and 0.7 +/- 0.5/5.1 +/- 1.3 females). |
8041317 | [The suitability of bacterial preparations intended for mosquito control in salt water]. | Laboratory experiments have brought the authors to a conclusion on the efficacy of B. thuringiensis and B. sphaericus-based insecticides in salty water mosquito breeding sites. Species difference of mosquito larvae susceptibility to the insecticides related to salt concentration in water were detected. |
8041316 | [The morphofunctional changes in the ovarioles of blood-sucking mosquitoes (Diptera, Culicidae) during oogenesis. 4. The cells of the ovariole lumen]. | Lumen cells were found in female ovarioles of 15 bloodsucking mosquitoes studied, that were called so because of their similarity with the cells found by R. King in Drosophila melanogaster. The mosquito lumen cells differ by the morphology and position in the ovariole. Seven morphologic variants were distinguished: (1) irregular-shaped cells in the ovarian filament; (2) large spheroid cells in ovariolar filament; (3) round cells under ovariolar membrane near the connective stems or end pedicle; (4) drop-shaped cells, attached by their 'tail' to the ovariole; (5) 'lenticular' (in the transverse section) cells, often attached to the ovariole; (6) kidney-shaped cells spread on ovariolar surface; (7) large round cells in egg sac granulated sites. The authors suggest that all these cells may be referred to the same type, possibly to polygonal phagocytic cells in different periods of their activity. These cells seem to play an important role in abortive oogenesis processes in mosquitoes. The more abnormal is ovariolar function, the more lumen cells this ovariole contains. Such cells were the most incident in Anopheles females: sometimes a single ovariole contained as many as 15-17 lumen cells. |
8041315 | [The comparative isoenzyme characteristics of Old World Leishmania strains from different geographical regions (Africa, the Near East, Central Asia)]. | Thirty-four strains of seven Old World Leishmania species were analyzed for 12 enzymes. The findings indicate isoenzymatic profile geographic changeability of some Leishmania species: Tested L. major, L. tropica, and L. infantum strains from Africa, Middle East, and Central Asia were found to be represented by individual zymodemes differing between themselves by 3-5 enzymes. Many identical zymodemes could induce in some cases skin, in other visceral symptoms in the carriers. Great isoenzymatic affinity between L. tropica and L. donovani sensu lato strains was detected. The nature of intraspecies Leishmania zymodeme variability being virtually not studied at present, the authors emphasize the usefulness of clone studies. |
8041313 | [An analysis of the results of clinical trials of praziquantel analogs in intestinal cestode and trematode infections. 1. The treatment of intestinal cestode infections (diphyllobothriasis, taeniasis, hymenolepiasis)]. | The studies have demonstrated a high efficacy of prasiquantel in therapy of enteric cestodiases. No differences in the efficacy and tolerance of prasiquantel analogs manufactured by various pharmaceutic firms (azinox, CIS; pikiton, China; biltricide, Bayer, India; cesol, Merk, India; cisticide, Merk India) were detected. Prasiquantel single dose (15 mg/kg) efficacies in diphyllobothriasis, taeniarhynchiasis, and taeniasis made up 91.4, 98.5, and 100%, respectively. In hymenolepiasis the efficacy of a total dose (40 and 50 mg/kg given twice with a 10-day interval) was 88.9%. |
8041314 | [The routes of helminth egg appearance on the territory of recreational areas and sites of the lower Don River]. | Sanitary and parasitologic problems of recreation use of water bodies and coast lines are still to be studied. The author has examined the routes of invasion at recreation areas by the lower Don river. The river bed depositions and water as well as coastline soil were found contaminated with helminthic eggs. These eggs were brought by sewage water, feces, and surface flow. Effective ecologically justified measures should be developed to prevent it. |
8041312 | [The efficacy of a new Russian preparation metiazol in experimental aspiculariasis in mice]. | The efficacy of metiasole, a new Russian analog of albendasole, reproduced at the E. I. Martsinovskiĭ Institute of Medical Parasitology and Tropical Medicine, was studied in mice with Aspiculuris tetraptera invasion. Metiasole efficacy and acute toxicity were comparable to those of embovin and superior to those of medamin. Relationship between the drug efficacy and its doses and number of injections was analyzed. |
8041311 | [The potential for using an integrated method of soil disinfection in microfoci of geohelminthiases]. | Polycarbocin-lupine and polycarbocin-pea systems were found to exert a marked ovicidal effect providing decontamination of the top soil layer from ascarid eggs for 3 months. A combination of 4-5 mg of polycarbacine and 25-30 lupine or 20-30 pea plants per m2 was found the optimal. If combined with pea, 3 g of the agent is sufficient. The integrated method for soil deinvasion seems to be particularly promising in microfoci of helminthiasis. |
8041308 | [Opisthorchiasis among the population in the areas along the route of the Urengoĭ-Surgut-Kurgan gas pipeline]. | The authors assess opisthorchiasis situation at settlements near compressor stations along 2000 km gas line crossing Western Siberia from North to South. The mean opisthorchiasis incidence was found to be 17.4 +/- 0.7% (from 1.6% in the Extreme North to 38% in hyperendemic regions). Judging from children invasion rate (4.4%), the risk of opisthorchiasis invasion is high in this territory. Opisthorchiasis incidence in the newcomers who lived for more than a decade in this region was up to 38.4% (52.6 in hyperendemic zone). Consumption of improperly prepared salted fish was the most important risk factor. Serologic diagnosis making use of modified enzyme immunoassay test systems is advisable for epidemiologic survey and detection of population invasion rate. |
8041307 | [The medicosocial significance, epidemiology and prevention of enterobiasis at the present-day stage]. | Presents data on enterobiasis prevalence, medicosocial significance, and epidemiologic features in the former USSR and CIS. Analyzes the causes of ineffective control of this disease. Emphasizes the necessity of simultaneous solution of medical and nonmedical (social) problems. Distinguishes the priority trends in the disease prevention. |
8041306 | Effect of Escherichia coli lipopolysaccharide on Bacteroides fragilis abscess formation and mortality in mice. | To study the mechanism of synergism between Bacteroides fragilis and Escherichia coli, the effect of sublethal dose of E. coli lipopolysaccharide (LPS) (25 micrograms/mouse) was checked on B. fragilis abscess formation. LPS was administered prior or after inoculum injection. No significant difference in the abscess size was observed at necropsy on day 6. However, all the groups receiving LPS showed higher incidence of recovery of additional intestinal bacteria (23.5-45.5%) from the abscess pus. When LPS was given 4 hr prior to inoculum administration, 83-100% mortality was observed. Detailed investigation showed autoclaved cecal contents alone could also cause similar mortality. Studies with stimulation of endogenous cytokines by E. coli LPS demonstrated induction of all of them within 3 hr in the blood stream with TNF-alpha demonstrating peak at 1 hr, IL-1 alpha and IL-6 at 4 hr and IFN-gamma between 6-9 hr with moderately high levels at 4 hr. This E. coli LPS-triggered cytokine cascade possibly gets further stimulated by injection of autoclaved cecal contents containing high concentration of endotoxins (1.6 x 10(5) EU/ml) contributed by dead bacteria and lead to the mortality of animals. |
8041305 | Inflammatory and phagocytic response to experimental Campylobacter jejuni infection in mice. | After intraperitoneal inoculation with Campylobacter jejuni BALB/c, Swiss and DBA mice show a peritoneal inflammatory response of different intensity. Only BALB/c mice have a strong peritoneal response. Simultaneous intraperitoneal inoculation of C. jejuni plus FeCl3 increase both inflammatory response and phagocytic activity in Swiss mice, without production of diarrhea. Some thermostable compounds of C. jejuni have a very strong chemotactic activity against peritoneal cells of mice, whereas a diffusible, thermolabile and glutaraldehyde-resistant factor has an inhibitory effect over murine peritoneal cell phagocytosis. Bactericidal activity of peritoneal cells increased after in vitro re-challenge with C. jejuni. Bacteremia is present in all the mice strains tested, but the clearance is quick in DBA and slow in BALB/c and Swiss mice. These experiments confirm that in mice, peritoneal non-specific mechanisms of defense, such as macrophages, play an important role in order to control C. jejuni infection. |
8041304 | Identification of hepatitis C virus subtype 3b (HCV-3b) among Japanese patients with liver diseases using highly efficient primers for reverse transcription-polymerase chain reaction. | With a reverse transcription-polymerase chain reaction method that utilized highly efficient primers, the NS5 region of hepatitis C virus (HCV) genome could be amplified from all of the 24 serum samples randomly obtained from Japanese patients with liver diseases. Subtype analysis on the basis of nucleotide sequence similarities of the amplified fragments revealed that 2 out of 24 Japanese patients (8.3%) were infected with the recently identified subtype HCV-3b, which had been thought to be rare in Japan. |
8041303 | Greater amount of HCV-RNA in tears compared to blood. | Plasma, tear fluid and swabs from eye, nose and pharynx of 33 patients were examined for presence of hepatitis C virus (HCV) RNA by polymerase chain reaction (PCR). All samples from plasma, tear fluid and eyeswabs were found to show a positive reaction in HCV-RNA PCR. Remarkably, we regularly found greater amounts of amplification products in tear fluid and eyeswabs compared to plasma using the same conditions for sample preparation. |
8041302 | Degradation of a polymerase chain reaction (PCR) product by heat-stable deoxyribonuclease (DNase) produced from Yersinia enterocolitica. | When crude deoxyribonucleic acid (DNA) preparations by boiling were used for the polymerase chain reaction (PCR) from pathogenic and non-pathogenic Yersinia enterocolitica strains, the amplified products were degraded after their storage at 4 C. The degradation of products was prevented by the addition of ethylenediaminetetraacetate (EDTA) or treatment with proteinase K. These findings indicate that Y. enterocolitica produced heat-stable deoxyribonuclease (DNase). Proteinase K treatment would be recommended to prevent heat-stable DNase contamination in the DNA preparations for PCR from Y. enterocolitica strains. |
8041301 | Cytoplasmic membrane-associated protein (CAP) isolated from Streptococcus pyogenes: as a new bacterial superantigen. | A protein isolated from the cytoplasmic membranes of Streptococcus pyogenes (cytoplasmic membrane-associated protein, CAP) stimulated human T cells in vitro to induce their mitogenic response. This CAP-induced T cell proliferation required the presence of nylon-adherent accessory cells (AC) of either autologous or allogeneic origin in the reaction mixtures. In addition, the reaction was inhibited by monoclonal antibodies (mAbs) against major histocompatibility complex (MHC) class II molecules, HLA-DR and -DQ, but not -DP. Human lymphoid cell lines positive for HLA-DR but not those lacking it were also effective as AC for the reaction. A binding test using fluorescein-labeled protein revealed that CAP bound to the adherent monocytes and HLA-DR+ but not to -DR- lymphoid cell lines. The proliferative response of T cells to CAP was, however, not inhibited by the addition of the lysosomotrophic agent NH4Cl to the reaction mixtures. These results suggest that the presentation of CAP by AC to human T cells is mediated through binding of the protein to the MHC class II molecules but without being processed in the AC. The proliferative response of T cells was also found to be inhibited by addition of anti-CD2, -CD3 or -T cell receptor (TcR) mAbs. A major population responding to CAP was CD3+4+8- T cells. CAP also appears to stimulate T cells bearing V beta 8 sequences much more selectively than T cells bearing other V beta s. These results indicate that this streptococcal membrane protein, CAP, may be a new protein belonging to a group of bacterial superantigens. |
8041300 | Protective capacity of L-form Salmonella typhimurium against murine typhoid in C3H/HeJ mice. | L forms of Salmonella typhimurium LT2 conferred strong protection to a lethal challenge with its parental bacterium on innately hypersusceptible C3H/HeJ mice, and its minimal protective dose was approximately 150 L-forming units. Although L-form S. typhimurium was avirulent for C3H/HeJ mice, it multiplied slowly in both the liver and spleen with the maximal growth 2-3 weeks after immunization and thereafter it persisted in the liver until 24 weeks. Protective immunity began to work between 4 and 6 weeks after immunization, and it remained active as long as the L forms colonized the liver (until 24 weeks after immunization). Vaccination with the L form induced a population of T cells responding to L-form whole-cell lysate (WCL), while delayed-type hypersensitivity (DTH) to the extract of S. typhimurium was induced after the establishment of solid immunity. Moreover, neither T-cell responses nor DTH to heat-killed S. typhimurium was generated. In addition, antibody responses were elicited to WCL but not to heat-killed S. typhimurium. These results indicate that protection conferred by the L forms is attributable to the persistent colonization of the L forms rather than the presence of DTH, and also that Salmonella cytoplasmic antigens are involved in induction of immunological responses by vaccination with the L forms. |
8041299 | Epidemiological and ecological studies of Japanese encephalitis in Okinawa, subtropical area in Japan. II. Prevalence of Japanese encephalitis antibody in residents in Okinawa, Miyako and Ishigaki islands. | During 1989 to 1990, human sera were collected by age groups in Okinawa (the northern, central and southern areas), Miyako and Ishigaki islands and examined for the neutralization (N) antibodies to two strains, Nakayama (vaccine strain) and C307 (Okinawan strain), of Japanese encephalitis (JE) virus. In Okinawa island, the N antibody positive rate to C307 was higher than that to Nakayama, while in Miyako and Ishigaki islands, the positive rate to Nakayama was higher than that to C307, suggesting that JE virus transmission rate was higher in Okinawa than in Miyako and Ishigaki islands. In Okinawa Prefecture, JE vaccine had not been administered to most of residents over 31 years of age at the time of serum collection. In residents over 31 years old, the positive rate to C307 was highest in the north of Okinawa (83.3%) and was lowest in Miyako (26.3%), with the second lowest in Ishigaki (33.3%). The distribution of N antibody titers to C307 gave hyperbolic patterns in the 0-5 age groups in Miyako and Ishigaki, and also in the 31-40, 41-50 age groups in Miyako and the 41-50 age group in Ishigaki, suggesting low rates of natural infection in these 4-5 decades in both islands. In residents of ages subjected to JE vaccine, a characteristic pattern was obtained, in which the curves to Nakayama shifted to higher titers than those to C307, suggesting that the first antigenic stimulation was caused by vaccine, not by natural infection of JE virus. |
8041298 | Epidemiological and ecological studies of Japanese encephalitis in Okinawa, subtropical area in Japan. I. Investigations on antibody levels to Japanese encephalitis virus in swine sera and vector mosquito in Okinawa, Miyako and Ishigaki islands. | From 1985 to 1989, serum specimens of swine raised in the northern, central and southern areas in Okinawa island were examined for Japanese encephalitis (JE) virus antibody by ELISA and hemagglutination-inhibition test. The antibody positive rate was found to be higher in the north and central than in the south. The 2-mercaptoethanol sensitive antibody to JE was detected mostly in June and July, and occasionally in other months except February and March. There was no month when all specimens from three areas turned antibody-negative simultaneously, indicating that JE virus transmission to swine lasted longer in Okinawa island than in other temperature areas in Japan. From 1986 to 1991, the vector mosquitoes (Culex tritaeniorhynchus) were collected in a pig farm in the south of Okinawa island. A total of 153 strains of JE virus was isolated from the vector mosquitoes mainly in June. In Miyako and Ishigaki islands, the antibody positive rate in swine sera was found to be extremely low, compared with that in Okinawa island. In Miyako island, where no paddy rice field is cultivated, a few adults as well as larvae of the vector mosquito were collected, while in Ishigaki island, where there are many watered rice fields, a lot of adults as well as larvae were collected. Although the environmental situation is quite different between the two islands, JE virus transmission appeared to be very low in both islands. |
8041297 | Effect of BV-araU and acyclovir on varicella-zoster virus replication with various length and timing of drug exposure. | We studied antiviral effects of 1-beta-D-arabinofuranosyl-5-[(E)-2-bromovinyl]uracil (BV-araU) and acyclovir against varicella-zoster virus (VZV) multiplication varying the length or timing of drug exposure. First, residual anti-VZV effect of drugs, exposed to cells for various periods followed by incubation in drug-free medium, was determined by the plaque inhibition assay. None of the drugs showed activity when removed within 24 hr of incubation. Weakened efficacy of BV-araU was seen in 2 days of treatment. When it was removed after 3 or 4 days, the ED50 was as low as that for cultures in which the drug was not removed. Still, plaque inhibition was not complete even at high concentrations. Acyclovir inhibited plaque formation only by 50% or less in 2 days of treatment. It gave a much higher ED50 in 3 days of treatment than that observed without drug removal. In the experiments, in which BV-araU was added to VZV-infected cells 1 day after infection, BV-araU immediately suppressed increase in the number of infective centers at a concentration of 0.001 microgram/ml, and reduced it at concentrations of 0.01 microgram/ml or higher. The reduction of infective centers was seen with a dose-dependent manner when added 2 or 3 days after infection. BV-araU stimulated the decrease in the number of infective centers when added 4 days after infection. This inhibitory effect of acyclovir was very weak. Microscopic observations supported the above results. BV-araU was still much superior to acyclovir in the anti-VZV effect when the length and timing of drug exposure were varied. |
8041296 | Purification and characterization of an acid phosphatase from Mycoplasma fermentans. | An acid phosphatase associated with the cell membranes of Mycoplasma fermentans was released from the membranes with Triton X-100, then purified by ion-exchange chromatography on DEAE-Sephacel and CM-Sepharose, followed by affinity chromatography on Con A-Sepharose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme revealed a single band with a molecular mass of 31.2 kilodaltons. The enzyme activity toward p-nitrophenyl phosphate was enhanced remarkably by Cu2+, Co2+ and Mg2+, but the activity was not inhibited by EDTA. The enzyme dephosphorylated O-phospho-L-tyrosine as well as p-nitrophenyl phosphate, but not O-phospho-L-threonine, O-phospho-L-serine, glucose-1-phosphate, phosphoryl choline and adenosine triphosphate. The level of the O-phospho-L-tyrosine phosphatase activity was the highest in Mycoplasma faucium and the second highest in Mycoplasma fermentans of all tested human mycoplasmas. |
8041295 | Use of spectrocolorimetry for study of lipid consumption by Trichothecium roseum. | Studies were carried out by means of spectrocolorimetry in order to determine the consumption of total lipids in cultures of Trichothecium roseum. This technique has the advantage of requiring very little specimen preparation. |
8041294 | Thin film formation by rough form lipopolysaccharide and interaction with cationic antibiotic polymyxin B. | A monolayer film of the rough form of lipopolysaccharide (LPS) from Erwinia carotovora at an air-water interface was transferred onto solid substrates to form a multilayer film. The LPS was deposited on hydrophobic graphite as well as on hydrophilic platinum plates. The thickness of the LPS film prepared by a single dipping and removal of the graphite was estimated at 2.7 nm by atomic force microscopy. The repeated dipping of the platinum plate indicated early saturation with reduced subsequent absorption from the pure water subphase, while successive transfers of the LPS were observed from a 2.0 mM MgCl2 solution. The LPS film on the quartz crystal microbalance (QCM) interacted with cationic antibiotic polymyxin B in the solution and exhibited a downward shift of resonant frequency and resistance in proportion to its concentration. The resonant resistance change against the resonant frequency axis was parallel in this interaction. The absorption of the antibiotic on the LPS film prepared in the presence of MgCl2 indicated an increase in mass, but little change in viscoelasticity. A multilayer film of LPS on the QCM was found suitable for subsequent characterizations. |
8041293 | Lethal photosensitisation of Staphylococcus aureus. | The purpose of this study was to determine whether toluidine blue O (TBO) could sensitise Staphylococcus aureus to killing by light from a low-power helium/neon (HeNe) laser. Suspensions of the organism were irradiated with light from a HeNe laser in the presence and absence of TBO and the survivors enumerated. A 95% reduction (9 x 10(7) cfu) in the viable count was achieved following irradiation with 0.88 J of HeNe laser light in the presence of 12.5 micrograms/ml TBO whereas no significant reductions in viability were found when suspensions were exposed to this dose of laser light in the absence of TBO. With higher doses (3.5 J) of laser light statistically significant kills (3 x 10(7) cfu) were obtained in the absence of TBO implying the presence of an endogenous photosensitiser in the organism. |
8041292 | Analysis of Sec 19-1 mutant of Saccharomyces cerevisiae. | Saccharomyces cerevisiae Sec 19-1 cells are secretion mutants defective at 37 degrees C. The cells were analysed in order to ascertain the effect of mutation temperature on cell wall formation. At the restrictive temperature of 37 degrees C, the Sec 19-1 mutants had 37 micrograms/mg N-acetylglucosamine in the wall cells, while the wild type S. cerevisiae showed 84 micrograms/mg hexosamine. The mutants Sec 19-1 showed a maximum activity of chitin synthetase of 0.113 nmoles/min/ml, and the activity increased to 0.33 nmoles/min/ml in the wild type cells. On the other hand, variations of chitin distribution in the wall cells occurred at the restrictive temperature, but changes in actin organization were not evident. The results indicated that the mutation caused variations in the levels of N-acetylglucosamine and chitin synthetase, as well as in cell wall chitin distribution. |
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