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Biomedical subjects

B Hoffman

Publications and source records attributed to B Hoffman.

117 records · Page 7Linked to original sources
PubMed1970

The intracellular transport and distribution of cysteamine phosphate derivatives.

Radioautography and extractive techniques were used to analyze the transport of cysteamine phosphate and its derivatives in salamander oocytes. The quantitative relations among the processes involved - membrane permeation, enzymatic dephosphorylation, binding through mixed disulfide formation, and cytoplasmic diffusion - were elucidated. Within the detection limits, all of the intracellular material is present as dephosphorylated derivatives. Cytoplasmic diffusion is effectively slowed by binding (the "chromatographic" effect) and makes an appreciable contribution to cellular flux rates. As a consequence, one can observe by radioautography a cortical diffusion ring which spreads inward as a function of influx time, while also increasing in peak density because of the finite membrane permeability. Good agreement was found between the transport parameters determined by radioautography and those from influx data for the whole oocyte. The ratio of nuclear to cytoplasmic concentrations of the cysteamine phosphate derivatives at equilibrium is about 0.4. The nuclear membrane is, however, a negligible barrier to transport, and the asymmetry appears to arise primarily from the quantity and sulfhydryl content of the binding proteins in the two compartments.

Animals↗
PubMedDate not supplied

Labetalol in essential hypertension.

Labetalol is an orally active adrenoreceptor-blocking drug which is a competitive antagonist of both alpha- and beta-adrenoreceptor sites. Thirty patients with essential hypertension were admitted to the study. The mean of initial systolic and diastolic blood pressures of these patients was 160/101 +/- 3/1 supine and 155/104 +/- 3/1 mm Hg standing, and the mean blood pressures at the end of the 16 week trial was 142/90 +/- 4/2 supine and 131/91 +/- 3/2 mm Hg standing. The average dose of labetalol was 546 mg: eight patients received a dose of 300 mg, seven a dose of 600 mg, six a dose f 900 mg, and two a dose of 1,200 mg. The patients who needed the highest doses of labetalol had an initial lowering of their blood pressures followed by a gradual increase despite the higher doses of labetalol. There was no significant change in the mean peripheral renin activity value. Side effects were reported by 18 of the 30 patients, but only 1 patient withdrew for this reason. Two patients were considered to be treatment failures. Overall, labetalol was found to be an effective antihypertensive agent in 15 patients.

Adult↗
PubMedDate not supplied

Cancer survivors at work: job problems and illegal discrimination.

Approximately 25% of the five million people in the United States with a cancer history experience disparate treatment in employment solely because of their medical histories. Many employers do not realize that more than half of the people diagnosed with cancer in 1988 in the United States will overcome their illness, that cancer is not contagious, and that cancer survivors have relatively the same productivity rates as other workers. Decisions to deny employment opportunities to cancer survivors that are based on misconceptions about cancer instead of the individual's ability to perform the job may violate the survivor's legal rights. Discrimination against individuals with a history of cancer, who are qualified for jobs, violates most federal and state laws that prohibit employment discrimination based on actual or perceived disabilities. Health professionals, as well as survivors themselves, must take action on three fronts to combat cancer-based discrimination: public and professional education, individual and group advocacy, and appropriate use of legal remedies.

Civil Rights↗