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Biomedical subjects

B Silverman

Publications and source records attributed to B Silverman.

At least 37 records · Page 2Linked to original sources
PubMed1990

The sulphated glycosaminoglycan levels in synovial fluid aspirates in patients with acute and chronic joint disease.

Proteoglycan levels were measured in a series of synovial fluid samples from patients with acute and chronic joint diseases using a modified chemical dye binding method. Levels found in 50 miscellaneous inflammatory arthritis fluids (mean = 173.2 +/- 90.9 micrograms/ml) were higher than found in either 50 with rheumatoid arthritis (96.3 +/- 31.3 micrograms/ml) or 50 with osteoarthritis (83.8 +/- 27.3 micrograms/ml). For comparison, proteoglycan levels were measured in 15 cadaver synovial fluids (98.9 +/- 44.2 micrograms/ml) and 12 synovial fluids from patients with sports injury (163.7 +/- 79.4 micrograms/ml). Patients were recruited into a trial where synovial fluid was aspirated as often as possible over a 6-month period during which the patients were followed using a number of well proven clinical parameters. No correlation was found between the degree of joint destruction as measured by X-ray damage and the concentration or total amount of proteoglycan in the synovial fluid. In addition, there was no correlation between the level or total amount of proteoglycan and any clinical parameter of disease activity.

Acute Disease↗
PubMed1990

Training perception of acute airflow obstruction.

Ten asthmatics selected for their tendency to experience frequent acute exacerbations were instructed in peak flow measurement. Each subject then recorded estimated peak flow (EPF) and measured peak flow (PF) at home twice daily. Data for up to 56 consecutive observations (4 weeks) per subject were analyzed. The correlation coefficient between EPF and PF following PF drops of 15% was .993 overall and was not significantly different following PF drops even greater than 25%. The absolute and proportional differences between PF and EPF were also not significantly affected by the magnitude of PF drop but decreased over time indicating improved accuracy of estimates with practice. Asthmatics can be trained to estimate accurately acute drops in airflow. Such ability has not been demonstrated in prior studies which utilized verbal symptom reports as indicators of subjective perception of airflow. Accurate perception would be a useful aid in achieving early recognition of acute exacerbations and in improving medication compliance. It is an adjunct to regular peak flow measurement, not a substitute for it.

Airway Obstruction↗
PubMed1986

Pulmonary disease in children with acquired immune deficiency syndrome and AIDS-related complex.

Two major pulmonary diseases were defined on the basis of lung biopsies in 15 children with acquired immune deficiency syndrome (AIDS) or AIDS-related complex. Pneumocystis carinii pneumonia was observed in eight children, and pulmonary lymphoid hyperplasia in six. One child had nonspecific interstitial pneumonitis. Children with P. carinii pneumonia had more severe hypoxemia, with higher alveolar-arterial oxygen gradients, and higher isomorphic elevations of serum lactate dehydrogenase. Clinically, children with pulmonary lymphoid hyperplasia were older, and had digital clubbing, parotid gland enlargement, and elevated serum IgG levels. Results of serologic assays and lung tissue analysis were suggestive of persistent Epstein-Barr virus infection exclusively in patients with pulmonary lymphoid hyperplasia. Recognition of the clinical and laboratory findings characteristic of each entity may assist in the differential diagnosis without the need of surgical biopsy.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Polymyalgia rheumatica/giant cell arteritis in a Cambridge general practice.

The aim of this study was to establish the incidence and prevalence of polymyalgia rheumatica/giant cell arteritis in general practice. Patients with this disorder, whether previously diagnosed or not, were ascertained by using a questionnaire administered by interview, and all received full clinical and laboratory assessment. A total of 579 patients aged 65 and over was seen, and 19 (33/1000) had been diagnosed or developed symptoms within the previous eight years. Thus the calculated annual incidence in those aged 65 and over was about 4/1000. The figures from this first large scale study of polymyalgia rheumatica/giant cell arteritis in general practice are much higher than those from studies carried out in hospital. The questionnaire was effective in both identifying known cases of polymyalgia rheumatica/giant cell arteritis and detecting new cases. As this is a treatable disorder, it is important that doctors become aware of how common it is in elderly people.

Aged↗
PubMed1982

Complement activation by isolated myelin: activation of the classical pathway in the absence of myelin-specific antibodies.

Many pathological conditions of the central nervous system involve damage to and removal of myelin membrane. Very little is known about initiation of this membrane damage and the mechanisms of disposal of the damaged tissue. We are interested in the interaction between complement (the components of complement are designated C1, C2, C3, etc.) and myelin membranes and the possible role of complement in amplifying myelin damage and in the disposal of damaged myelin in vivo, because activation of complement generates both membrane-attack complexes and opsonin(s). In this study, we found that isolated rat or human myelin consumes complement in the absence of specific antibodies. Activation of complement was demonstrated by showing C3 cleavage in fresh serum incubated with myelin. Incubation of central nervous system myelin with C2-deficient serum produced no C3 consumption and only minor factor B conversion, thus excluding the alternative pathway of activation. Involvement of the classical pathway was shown directly by the C1 fixation and transfer assay. Myelin incubated with C2-deficient serum or with purified C1 and then washed contained C1 activity that could lyse sheep erythrocytes sensitized with anti-Forssman IgM antibody and carrying C4, together with C2 and C3-C9. Membranes in brain tissues other than myelin (heavy membrane fraction obtained on sucrose density gradient centrifugation) were unable to activate C1.

Animals↗
PubMed1982

Ethanol-provoked disturbances in the binding of zinc to rat jejunal mucosal proteins.

The present investigation was undertaken to determine whether administration of ethanol by intragastric intubation to rats modifies the binding of radioactive zinc to its binding proteins in the jejunal mucosa. These studies were prompted by the frequent observation of abnormalities in serum and urine zinc concentrations in alcoholic patients and the necessity to determine whether alcohol diminishes intestinal protein binding of zinc, the first step in zinc absorption. Adult female rats received intragastric ethanol by intubation, either daily for 10 days, or only 1 hour prior to death. After death by decapitation, the small intestinal was removed, and mucosal cell extracts prepared by homogenization and centrifugation. These extracts were incubated with 65ZnCl2, and gel filtration chromatography was performed with Sephadex G-100. A major difference in the chromatographic profiles between control and alcohol-treated animals was observed: binding of zinc to high molecular weight proteins was reduced and that to low molecular weight proteins was increased. These differences occurred both 10 days and 1 hour after ethanol. The finding of diminished binding of zinc to high molecular weight jejunal proteins may represent the first step leading to diminished intestinal absorption of zinc in alcoholism.

Alcoholism↗
PubMed1981

A method for assessing the quality of a randomized control trial.

A system has been constructed to evaluate the design, implementation, and analysis of randomized control trials (RCT). The degree of quadruple blinding (the randomization process, the physicians and patients as to therapy, and the physicians as to ongoing results) is considered to be the most important aspect of any trial. The analytic techniques are scored with the same emphasis as is placed on the control of bias in the planning and implementation of the studies. Description of the patient and treatment materials and the measurement of various controls of quality have less weight. An index of quality of a RCT is proposed with its pros and cons. If published papers were to approximate these principles, there would be a marked improvement in the quality of randomized control trials. Finally, a reasonable standard design and conduct of trials will facilitate the interpretation of those with conflicting results and help in making valid combinations of undersized trials.

Clinical Trials as Topic↗
PubMed1976

Self-image and its relation to denture acceptance.

A study was initiated to determine whether a relationship exists in geriatric patients between self-image and the extent of their denture acceptance. Three assessing instruments were employed, namely, a "Focused Interview," the embedded-figures test, and projective figure drawings. Scores obtained were compared with scores on the Denture-Acceptance Rating Scale. The research results derived from the data follow: 1. Comparison of the degree of denture acceptance with the scores on all three assessing instruments showed significant relationships. Therefore, the hypothesis under study was accepted. 2. The "Focused Interview" appeared particularly well suited to a geriatric population, because it was nonthreatening, provided a communication outlet, and can be readily employed by a practitioner. 3. The embedded-figures test and the projective figure drawings appeared less appropriate for this population because of factors such as psychomotor retardation, perceptual difficulties, and diminution of ego strength which accompany the aging process. 4. The men in this study appeared to accept dentures more readily than the women, manifested higher morale, and were more field-independent. 5. Employed subjects, as compared to unemployed, showed significantly greater denture acceptance, higher morale and self-image, and a greater degree of field-independence. These factors appeared related to greater flexibility of adaptation. 6. Socioeconomic factors appeared to be significantly and positively related to morale factors. 7. Complaints regarding dentures were largely of a physical nature. They appeared to relate primarily to difficulties with adjustment to the new artifact which represented an alteration of body image for the subjects. 8. The study provided corroborative evidence of the need for the dentist to make an initial assessment of those personality factors in his patients which might limit his ability to provide adequate dental services.

Aged↗
PubMed1975

Echocardiographic manifestations of postinfarction ventricular septal rupture.

The echocardiographic features of three patients with postinfarction ventricular spectal rupture are described. All patients showed a decreased or paradoxical motion on the ventricular septum, and two of the patients demonstrated an unusual motion of the tricuspid valve. There were no abnormalities in mitral valve motion. The echocardiogram can be helpful in the diagnosis of postinfarction ventricular septal rupture and can assist in distinguishing this condition from acute disruption of the mitral valve complex.

Aged↗
PubMed1973

Accessibility of DNA in chromatin to DNA polymerase and RNA polymerase.

The accessibility of DNA in chromatin to both exogenous DNA polymerase and RNA polymerase is slight when compared to isolated DNA. DNA in extracted chromatin is somewhat more accessible to these enzymes than is DNA in the chromatin of isolated nuclei; and the DNA template of chromatin is more accessible to DNA polymerase than to RNA polymerase. In these experiments we have given much attention to the technique of scintillation counting, since artifacts arising in this procedure can lead to erroneous conclusions.

Adenosine Triphosphate↗
PubMed1973

Effects of selective extraction of histones on template activities of chromatin by use of exogenous DNA and RNA polymerases.

Exogenous DNA and RNA polymerases were used to measure the template activity of DNA in chromatin in isolated thymus nuclei from which lysinerich or arginine-rich histones were selectively extracted. Measurements were on nuclei containing 20-1200 mug of DNA per ml, the distinctions becoming clear at the higher concentrations. Experiments with RNA polymerase showed only moderate increases in template activity upon extraction of histone, although the removal of lysinerich histone had a greater effect than that of arginine-rich histone. DNA polymerase action on nuclei minus lysinerich histone achieved high results, exceeding even those on DNA itself.

Animals↗
PubMed1973

Addition of histones to histone-depleted nuclei: effect on template activity toward DNA and RNA polymerases.

The ability of histones to block the accessibility of DNA in chromatin to DNA and RNA polymerases was measured by addition of lysine-rich or arginine-rich histones to nuclei selectively depleted of these histones. By this procedure nuclei were obtained in which all of the original lysine-rich histone in the chromatin was replaced by arginine-rich histone. Conversely in other nuclei, additional lysine-rich histone replaced some of the endogenous arginine-rich histone. Lysine-rich histone was much more effective than arginine-rich histone in blocking accessibility to DNA polymerase. Both classes of histone inhibited template activity toward RNA polymerase to a similar extent. In addition to lysine-rich histone and total arginine-rich histone, phosphorylated lysine-rich histone, two fragments of lysine-rich histone produced by cleavage with N-bromosuccinamide, and fractions IIB and IV of arginine-rich histone were added to histone-depleted nuclei. With both DNA and RNA polymerases as probes, no differences in inhibition of template activity were found when native lysine-rich histone was compared to phosphorylated lysine-rich histone. Similarly, fractions IIB and IV were indistinguishable from total arginine-rich histone. On a molar basis, the carboxyl fragment of lysine-rich histone was as effective as intact lysine-rich histone only when the amino fragment was added to it. By itself, the amino portion of lysine-rich histone was without inhibitory effect in the RNA polymerase assay and resulted in only slight inhibition of template activity toward DNA polymerase.

Arginine↗