Search PubMed⌕ Search

Biomedical subjects

M Stein

Publications and source records attributed to M Stein.

At least 289 records · Page 16Linked to original sources
PubMed1990

Rheumatic disorders in Zimbabwe: a prospective analysis of patients attending a rheumatic diseases clinic.

The pattern of rheumatic disease in Africa differs from that in Europe and the United States and these differences may provide clues to its cause or pathogenesis. In a six month prospective analysis of 141 patients (83 female) attending a rheumatic diseases clinic rheumatoid arthritis was the commonest disorder, occurring in 49 patients. Twenty seven of the 49 (55%) were seropositive, 25 (51%) had erosive disease with rheumatoid nodules (13/49, 27%), and extra-articular complications (6/49, 12%), indicating a pattern of disease unlike the early reports from Africa. Systemic lupus erythematosus found in 18/141 (13%), gout in 12 (9%), ankylosing spondylitis in six (4%), and Reiter's syndrome in five (4%), in contrast with their rarity in previous reports from Africa, were not uncommon, whereas tropical polyarthritis was seldom diagnosed. The pattern of rheumatic disease in Harare, a large city, is changing to approximate more closely the pattern seen in developed countries.

Adult↗
PubMed1990

Adrenal steroid receptor binding in spleen and thymus after stress or dexamethasone.

Type I and II adrenal steroid receptor binding was measured in spleen and thymus of adrenalectomized (ADX) rats and intact rats at basal levels of corticosterone after 1 h of restraint stress or after exogenous administration of dexamethasone (DEX). Concurrent receptor determinations were made in the hippocampus and pituitary. Receptor binding measures in immune tissues and pituitary were less responsive to varying levels of endogenous hormones than binding measures in hippocampus. Compared with ADX rats, type I binding in spleen and pituitary of intact rats at basal levels of corticosterone was unchanged, whereas type I binding in the hippocampus was significantly decreased. Furthermore, despite peak levels of corticosterone, type II binding in spleen, thymus, and pituitary of stressed rats was also unchanged, whereas type II binding in the hippocampus of stressed animals was significantly lower. In contrast, DEX, a well-known immunosuppressant, reduced type II binding in immune tissues more than in the hippocampus. Because a decrease in receptor binding measured in vitro may reflect receptor activation in vivo, these results suggest that there may be considerable heterogeneity in the degree of activation of adrenal steroid receptor subtypes in immune, pituitary, and hippocampal tissue by endogenous and exogenous glucocorticoids.

Adrenalectomy↗
PubMed1990

Cricopharyngeal dysfunction in chronic obstructive pulmonary disease.

Dysphagia due to cricopharyngeal dysfunction is well known; however, there have been no previous data indicating an association between cricopharyngeal dysfunction and COPD. After observing marked cricopharyngeal dysfunction with aspiration in three patients who had frequent and severe exacerbations of COPD, we performed pharyngoesophageal examinations with videotaping in another 22 nonrandomized patients. Cineradiography or videofluoroscopic recording with capabilities of slow-motion and freeze-frame playback is mandatory, since the transit time of the bolus through the pharynx is rapid. Severe cricopharyngeal dysfunction was observed in 17 elderly patients with COPD. Deglutition disorders were elicited by careful questioning in 15 of these. In eight subjects, cricopharyngeal myotomy resulted in improvement of swallowing and complete or partial relief of acute exacerbations of respiratory distress. In one subject, myotomy relieved only the swallowing problem. The mechanism of cricopharyngeal dysfunction in elderly patients with COPD is unknown at this time, but may be related to gastroesophageal reflux, therapeutic agents, and/or alterations in pharyngoesophageal anatomic structures. We conclude that investigations for swallowing disorders should be considered in patients with COPD who have frequent acute exacerbations of respiratory distress.

Aged↗
PubMed1990

Case discussion in clinical pharmacology: application of small group teaching methods to a large group.

Problem-oriented case discussion is a valuable teaching tool in clinical pharmacology. Small groups are ideal for discussion but attempts to extend this to large groups often magnify the problems seen with small group discussion to an unacceptable extent. We describe a format which overcomes many of the problems encountered. The class is divided into groups of six students. Cases for discussion are distributed a week before discussion. Individual groups meet, research, discuss, form a consensus opinion and appoint a chairperson for each topic. The class meets and two groups are randomly chosen to discuss the first topic. The chairperson of the first group briefly presents the group's analysis of the problem. The chairperson of the second group then acts as an 'interrogator', questioning statements of fact, application of knowledge or logic, and offers alternative opinions. After discussion between the two groups the rest of the class join the discussion. Two new groups are chosen for the second case. This format facilitates self-directed learning, well-prepared participants and worthwhile discussion.

Group Processes↗
PubMed1990

Psychiatric perspectives of brain, behavior, and the immune system.

There is increasing evidence of reciprocal CNS-immune system interactions. The reaction of such processes to behavior and psychiatric disorders remains to be determined. It is not clear at this time if alterations in measures of the immune system associated with stress have clinical relevance, nor is there evidence that immune alterations are associated with the pathogenesis of psychiatric disorders. With the exciting advances in neurobiology, immunobiology, and biologic psychiatry, and with the availability of a wide range of methodologies, elucidation of the complexities of brain, behavior, and the immune system may be achieved.

Animals↗
PubMed1990

Therapeutic review: antibiotic prophylaxis for bacterial endocarditis.

A recent survey of antibiotic prophylaxis found that local practice often differed from that recommended by authoritative bodies such as the British Society for Antimicrobial Chemotherapy (BSAC) and the American Heart Association (AHA). Practitioners found the subject confusing and requested guidance. For these reasons we present current recommendations. Unfortunately all recommendations are based on animal studies and an understanding of the pathogenesis of bacterial endocarditis in humans. There are no controlled trials in humans on which to base guidelines, so rigidity is inappropriate. It is also important to realise that optimal prophylaxis will not eliminate bacterial endocarditis. In developed countries it has been estimated that only 10% of cases of endocarditis are theoretically preventable.

Anti-Bacterial Agents↗
PubMed1990

The spondyloarthropathies in Zimbabwe: a clinical and immunogenetic profile.

Spondyloarthropathies are rare in Africa and there is little data regarding HLA association. We prospectively studied 19 patients with spondyloarthropathy, recording clinical details and performing tissue typing (ABC loci). There were 9 patients with ankylosing spondylitis (8 males), all had severe spinal disease but none had ocular or cardiac involvement and HLA-B27 antigen was not found in any of the 7 patients tested; only one patient possessed a B7 crossreacting antigen. The 10 patients with Reiter's syndrome (8 males) had typical clinical features but again the HLA-B27 tissue type was not found. B7-CREG antigen was found in 7 of the 10 patients with Reiter's syndrome.

Adult↗
PubMed1990

Computed tomography and lateral ventricular asymmetry: clinical and brain structural correlates.

Asymmetry of the ventricles of the brain without an obvious cause is a common and intriguing radiologic finding. To understand this phenomenon better the authors conducted a 24-month study to compare clinical and structural manifestations of two groups of patients who had undergone head computed tomography (CT): group A comprised 249 patients with asymmetry of the lateral ventricles of the brain without space-occupying lesions, intracranial bleeding, recent infarction or trauma and group B comprised 266 patients with the above exclusion criteria but without ventricular asymmetry. The degree of ventricular asymmetry was classified as mild, moderate or severe, according to the ratio of the larger frontal horn diameter to the smaller one. The incidence of lateral ventricular asymmetry was 5.3%. The following clinical manifestations were more frequently present in group A: headaches (p = 0.002), seizures (p = 0.007) and positive human immunodeficiency virus (HIV) status (p = 0.02). Transient ischemic attacks were more prevalent in group B (p = 0.009). Independent predictors of headache were: younger age (p less than 0.001) and the degree of ventricular asymmetry (p = 0.02). Predictors of seizures were: younger age (p less than 0.001), ventricular asymmetry (p = 0.004) and the absence of septal deviation (p = 0.009). In group A, predictors of a higher degree of asymmetry were septal deviation (p less than 0.001) and older age (p = 0.008). The authors conclude that asymmetry of the lateral ventricles of the brain is a relatively common CT finding that has important clinical and brain structural correlates and deserves more attention in the field of imaging.

Adult↗
PubMed1989

Multiple primary thyroid and breast cancer in Israel, 1960-1976.

The occurrence of breast and thyroid multiple primary neoplasms has been evaluated using data from the Israel Cancer Registry. During the 16 years 1960-1976, 3,072 cases of thyroid cancer were registered in Israel. The occurrence of a second primary tumour was reported in 92 of these patients. In this latter group were 25 female patients (27%) with breast cancer, developing synchronously in 7 cases and metachronously in the remaining 18. The average age at the time of appearance of breast cancer was 50 years. Most of the patients (84%) were of European origin. The most common histological types were ductal and intraductal carcinoma and scirrhous adenocarcinoma. The possible aetiological factors common to breast and thyroid cancer are discussed. Efforts aimed at improving the survival of patients with thyroid cancer must incorporate strategies for the early detection and treatment of secondary breast cancer.

Adult↗
PubMed1989

Concerted action of cosolvents, chaotropic anions and thioredoxin on chloroplast fructose-1,6-bisphosphatase. Reactivity to iodoacetamide.

The incubation of chloroplast fructose-1,6-bisphosphatase with both dithiothreitol and protein denaturants made sulfhydryl groups available for reaction with [1-14C]iodoacetamide (10-12 mol iodoacetamide incorporated/mol enzyme). Digestion of S-carboxyamidomethylated enzyme with trypsin and polyacrylamide gel electrophoresis, in the presence of sodium dodecylsulfate, yielded two 14C-labeled fragments whose apparent molecular mass were 10 kDa and 16 kDa. In the absence of either dithiothreitol or protein denaturants the incorporation of iodoacetamide to the enzyme was lower than 4 mol. When chloroplast fructose-1,6-bisphosphatase was initially incubated with dithiothreitol (2.5 mM) and (a) high concentrations of both fructose 1,6-bisphosphate (4 mM) and Ca2+ (0.3 mM) or (b) low concentrations of both fructose 1,6-bisphosphate (0.8 mM) and Ca2+ (0.05 mM) in the presence of either 2-propanol (15%, by vol.), trichloroacetate (0.15 M) or chloroplast thioredoxin-f (0.5 microM) and subsequently subjected to proteolysis and electrophoresis, S-carboxyamidomethylated tryptic fragments had similar molecular masses. Thus, conditions that stimulated the specific activity of chloroplast fructose-1,6-bisphosphatase caused conformational changes which favoured both the reduction of disulfide bridges and the exposure of sulfhydryl groups. In this aspect, thioredoxin exerted structural and kinetic effects similar to compounds not involved in redox reactions (organic solvents, chaotropic anions). These results indicated that the modification of hydrophobic (intramolecular) interactions in chloroplast fructose-1,6-bisphosphatase constituted the underlying mechanism in light-activation by the ferredoxin-thioredoxin system.

Bacterial Proteins↗
PubMed1989

Sacrococcygeal extradural ependymoma.

A case of lumbosacral extradural myxopapillary ependymoma is reported. The clinical, embryologic, and therapeutic features of this rare lesion are presented. The unusual entity is discussed in the light of previous experience with extradural ependymoma in the lumbosacral region.

Adult↗