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Biomedical subjects

J Roseman

Publications and source records attributed to J Roseman.

26 records · Page 2Linked to original sources

Increase of HLA-DR4 in melanoma patients from Alabama.

This report describes the association of HLA-DR phenotypes in a population of 91 Caucasian melanoma patients compared with 106 Caucasian controls from the Sunbelt region of the United States. Over 75% of both patients and controls were born in Alabama or a surrounding state. There was a significant increase in the frequency of HLA-DR4 (chi 2 = 12.8; rho = 0.0003). This was present in 38.5% of the patients compared to a 16.0% frequency in the controls, producing a relative risk of 3.3. The difference in DR4 distribution remained significant after correcting for the number of antigens (rho c = 0.0018). The patients were then grouped into two categories, "low risk" and "high risk," based on their clinically assessed risk at presentation for metastatic involvement. The decrease of DR3 in the high-risk group (chi 2 = 5.2; rho = 0.02) suggested that it may represent a marker for long-term survival. Thus, it appears that susceptibility to developing melanoma may be associated with DR4 while survival may be associated with DR3.

Alabama↗

Comparison of the effects of carbamyl phosphate and sodium cyanate on protein synthesis and glutathione concentration in human sickle cell and rabbit reticulocytes.

Two carbamylating agents, carbamyl phosphate and sodium cyanate, are currently being evaluated as therapeutic drugs for the treatment of sickle cell anemia. Since the clinical usefulness of these drugs might be limited by toxicity, a comparative in vitro study of the relative inhibition of human sickle cell and rabbit reticulocyte protein synthesis was performed. Sodium cyanate was found to inhibit human sickle cell protein synthesis at concentrations one-eighth that of carbamyl phosphate. Carbamyl phosphate lowered reduced glutathione levels to a similar degree as sodium cyanate and was slightly more effective as an in vitro antisickling agent, which is evidence that carbamyl phosphate enters these cells. When rabbit reticulocyte protein synthesis was investigated, carbamyl phosphate was found to be noninhibitory at concentrations as high as 128 mol/mol of hemoglobin in the incubation medium, while cyanate was inhibitory at much lower concentrations. The effect of carbamyl phosphate on glutathione concentrations, however, was virtually identical to that of cyanate. These results show that the effect on protein synthesis does not result from the lowered glutathione levels. It is concluded that both the therapeutic and toxic effects of sodium cre, there might be differences in toxicity between animals and humans.

Anemia, Sickle Cell↗

X-ray resistant cell required for the induction of in vitro antibody formation.

Mouse spleen cells were separated into two populations on the basis of adherence to plastic. The recombination of these two populations was required for the in vitro antibody response to sheep erythrocytes. By separating the two populations from x-irradiated mice and combining each with the other population prepared from normal mice, it was demonstrated that the immunologic function of the nonadherent population only was highly sensitive to x-ray injury. In contrast, x-irradiation in doses as high as 1000 roentgens had no measurable effect on the immune function of adherent cells, that is, the population which first interacts with antigen and is composed principally of large phagocytic cells.

Animals↗

Qualitative issues in developing educational diagnostic instruments and assessment procedures for diabetic patients.

With one exception, psychometric analyses of the quality of instrumentation and educational assessment procedures for diabetic patients have not been reported in the literature. Following an extensive internal review process, a pilot test of 56 diabetic patients found that the newly developed instrument had a high degree of internal consistency for the major indexes, 0.89 and 0.85, respectively. An item analysis found individual questions to be of an acceptable quality. An analysis of interrater reliability of patient assessment procedures produced an r = 0.93. Some support for content and concurrent validity was noted. Using an external review by an expert panel, a revised instrument and protocol was used to conduct a formal field test of 100 diabetic patients. Levels of internal consistency similar to the pilot, 0.87 adn 0.86, were found. An item analysis produced similar positive results. While some support for concurrent validity of the data was found, little support for discriminant validity was evident. The instrument and assessment procedures need to undergo more extensive and rigorous examination of its psychometric characteristics, particularly stability and predictive validity.

Diabetes Mellitus↗