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Biomedical subjects

S Berk

Publications and source records attributed to S Berk.

16 recordsLinked to original sources
PubMed2001

Mass spectrometry screening of combinatorial mixtures, correlation of measured and predicted electrospray ionization spectra.

Methodology was developed to afford rapid characterization of multicomponent mixtures of small organic molecules prepared by split-and-mix combinatorial synthesis. This methodology involved the use of liquid chromatography mass spectrometry (LC/MS) combined with correlation analysis of measured versus predicted electrospray ionization mass spectra. Low-resolution mass spectra of complex mixtures revealed predictable patterns that confirm library products, assisted in identifying chemical synthesis errors, and assessed overall library integrity. In general, equal signal intensities were observed for most combinatorial mixture components, indicating that differences in electrospray ionization efficiency was not a major limitation to this approach. High-throughput data processing programs and informatics tools were used to speed data analysis and to simplify the presentation of the library characterization results. This approach has been used to characterize combinatorial libraries that were synthesized for a variety of drug-discovery programs. Examples are shown for library formats of 1, 40, 66, 280, and 400 component(s)/well. The applicability of this approach to large combinatorial mixtures should allow direct characterization of massive combinatorial libraries.

Journal Article↗
PubMed1999

Long-term exercise and atherogenic activity of blood mononuclear cells in persons at risk of developing ischemic heart disease.

CONTEXT: Increasing evidence demonstrates that atherosclerosis is an immunologically mediated disease in which the secretion of atherogenic and atheroprotective cytokines, by infiltrating blood mononuclear cells, plays an important role. It is not known whether long-term exercise alters this atherogenic and atheroprotective activity directly. OBJECTIVE: To determine the effect of long-term exercise on the atherogenic activity of blood mononuclear cells in persons at risk of developing ischemic heart disease. DESIGN: Before-after trial using a 6-month individualized, supervised exercise program, with an enrollment period from December 1996 to October 1997. SETTING: Hospital-based community wellness center. PARTICIPANTS: Of 110 persons who responded to a public request for volunteers, 52 met the inclusion criteria (risk ratio for myocardial infarction > or =1.7 based on serum complement and/or C-reactive protein levels, and normal exercise treadmill test results). Forty-three of the 52 enrollees (25 women [mean age, 49.7 years] and 18 men [mean age, 48.1 years]) completed the study; 9 withdrew for personal reasons. Additional risk factors for ischemic heart disease included hypercholesterolemia (65.1 %), a family history of coronary heart disease (62.8%), inactivity (60.5%), hypertension (32.6%), obesity (25.6%), smoking (11.6%), and diabetes mellitus (4.7%). MAIN OUTCOME MEASURES: Blood levels were compared at baseline and after the exercise program had been completed for the following: spontaneous and phytohemagglutinin-induced production of interleukin 1 alpha, tumor necrosis factor alpha, and interferon gamma (atherogenic cytokines), and interleukin 4, interleukin 10, and transforming growth factor beta 1 (atheroprotective cytokines) by blood mononuclear cells; lymphocyte phenotypes and mitogenic responses to phytohemagglutinin; and serum C-reactive protein levels. RESULTS: Subjects exercised for a mean of 2.5 (range, 0.3-7.4) hours per week. Mononuclear cell production of atherogenic cytokines fell by 58.3 % (P<.001) following the exercise program, where as the production of atheroprotective cytokines rose by 35.9% (P<.001). Changes in transforming growth factor beta 1 and in phytohemagglutinin-induced atherogenic cytokine production after the exercise program were proportionate to the time subjects spent performing repetitive lower-body motion exercises (P<.02), indicating a dose-response relationship. After the exercise program, changes in cellular function were reflected systemically by a 35% decrease in serum levels of C-reactive protein (P=.12). CONCLUSIONS: Our data suggest that long-term exercise decreases the atherogenic activity of blood mononuclear cells in persons at risk of developing ischemic heart disease. This may be a mechanism whereby physical activity protects against ischemic heart disease.

Arteriosclerosis↗
PubMed1993

Effect of moderate exercise on proliferative responses of peripheral blood mononuclear cells.

We studied the effects of 30 minutes of exercise on T lymphocyte counts and proliferative responses of peripheral blood mononuclear cells (PBMC) in 25 runners. Exercise resulted in a T lymphocytosis in the immediate post-exercise period in all subjects (p < 0.001), and reduced CD4+/CD8+ ratios in 22/25 subjects (p = 0.001). The change was due primarily to a 2.2-fold increase in CD8+ cells (p < 0.001). Exercise also reduced PBMC mitogenic responses to phytohemagglutinin (PHA) in 13/14 subjects (p = 0.049), and to pokeweed mitogen (PWM) in 11/14 subjects (p = 0.022), but not to concanavalin A. Postrun sera from 5 of 6 subjects inhibited PHA but not PWM responses of resting autologous PBMC with normal CD4+/CD8+ ratios (p < or = 0.05): indomethacin and monocyte depletion blocked the serum inhibition (p = 0.003, p = 0.0006, respectively). We conclude that post-exercise suppression of mitogenic responses to PHA is due to the release of a serum factor(s) capable of inducing prostaglandin synthesis by circulating monocytes, whereas exercise-induced suppression of PWM responses depends primarily on the reversal of CD4+/CD8+ ratios.

Adult↗
PubMed1988

Susceptibility of dysgonic fermenter 2 to antimicrobial agents in vitro.

Dysgonic fermenter 2 (DF-2) is a fastidious, gram-negative organism well recognized as a cause of fulminant septicemia in patients without spleens or patients with alcoholic cirrhosis. In vitro antibiotic susceptibility testing of eight strains with a Schaedler broth dilution technique revealed DF-2 to be susceptible to all of the antibiotics tested except aztreonam. Previous reports that DF-2 is aminoglycoside resistant were based on disk diffusion or agar dilution assays that may be less reliable given the slow growth of the organism and its requirement for CO2 incubation. Penicillin is commonly used as prophylaxis after dog bites and has excellent activity against DF-2.

Anti-Bacterial Agents↗
PubMed1983

Judgments of vocal affect by language-delayed children.

Judgment of vocal affect was studied in 19 language-delayed children and 19 children with normal language. The children responded to utterances spoken in an angry, happy, or sad tone of voice by pointing to a picture of an angry, a happy, or a sad face. The language-delayed children made significantly fewer correct judgments. The normal children judged all three emotions quite accurately, whereas the language-delayed children were very poor in judging sadness and showed a bias for judging all three emotional tones as anger. The language-delayed children tended to improve with age, but age trends in normal children were obscured by near-perfect performance of many children. The practical and theoretical importance of further research was discussed.

Affect↗
PubMed1980

Thymoma and the nephrotic syndrome: a report of a case.

A 48-year-old male presented with the nephrotic syndrome 3 years after resection and irradiation of a thymoma. Renal biopsy revealed membranous glomerulonephritis by electron microscopy. IgA, IgG, and C3 deposition were present in the glomerular basement membrane by immunofluorescence. There was no evidence of other autoimmune diseases or causes of the membranous glomerulonephritis. He has continued to have proteinuria and edema 1 year later.

Adult↗
PubMed1976

Noninvasive differentiation of cardiomyopathy from coronary disease; pulse transmission time and systolic time intervals.

Systolic time intervals and central pulse transmission time were compared in cardiomyopathy (CM) patients and age-and sex-matched patients with coronary artery disease (CAD). Significant differences were found in pulse transmission time (shorter in the CAD patients (p less than .001) and in the pre-ejection period (p less than .001), ejection time index (p less than .05), and in the ratio of the pre-ejection period to the left ventricular ejection time (p less than .001); all were markedly abnormal in the CM group. Pulse transmission time differences may have been the result of more generalized arteriosclerotic disease in the CAD patients. It appears that both systolic time intervals and pulse transmission time clearly distinguish CM from CAD.

Cardiomyopathies↗