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E J Benz

Publications and source records attributed to E J Benz.

114 records · Page 7Linked to original sources
PubMed1971

Defect in messenger RNA for human hemoglobin synthesis in beta thalassemia.

Functional messenger RNA for human hemoglobin synthesis was prepared from reticulocyte lysates of patients with homozygous beta thalassemia and sickle cell anemia. The messenger RNA stimulated the synthesis of human globin chains by a cell-free system derived from Krebs mouse ascites cells. In the presence of beta thalassemia messenger RNA, the system synthesized much less beta chain than alpha chain whereas in the presence of sickle cell anemia messenger RNA, nearly equal amounts of alpha and beta chains were synthesized. The beta/alpha synthetic ratios obtained in the cell-free system were similar to those obtained by incubating intact beta thalassemia and sickle cell anemia reticulocytes in the presence of radioactive leucine. The experiments provide direct evidence of a defect in messenger RNA for beta chains as a cause for the decreased synthesis of beta chains observed in beta thalassemia.

Anemia, Sickle Cell↗
PubMedDate not supplied

Na, K-ATPase isoform gene expression in normal and hypertrophied dog heart.

OBJECTIVES: The catalytic alpha subunit of the sodium-potassium ATPase, the target of digitalis glycosides, has three isoforms; the expression of these isoforms is tissue-specific and developmentally regulated. While the effect of pressure overload on Na, K-ATPase isoform expression has been studied in rodent heart, there are no systematic data on this question in hearts of larger animals, which differ from those of rodents both in isoform composition and in glycoside sensitivity. Thus, we investigated the expression of Na, K-ATPase isoforms in normal dog heart; we also examined the effect of experimental left ventricular hypertrophy on isoform expression. METHODS: hypertrophy was produced by aortic banding. Expression was assessed by quantitative Northern and Western blotting, immunofluorescence, and 3H-ouabain binding. RESULTS: RNA blotting indicated that the alpha 3 isoform represented 11% of Na, K-ATPase mRNA in normal dog LV. Normal dog LV expressed alpha 1 and alpha 3 protein, but no detectable alpha 2; immunoreactive alpha 1 and alpha 3 protein were also present in Purkinje fibers. There was a statistically significant decrease in total expression of all alpha isoform mRNA's in hypertrophied dog LV, resulting in a greater proportion of alpha 1. The expression level of the alpha 3 isoform mRNA and protein was lower in hypertrophied hearts. CONCLUSIONS: These results indicate a greater proportion of alpha 1 isoform pumps in experimental canine hypertrophy. Thus, shifts in NA, K-ATPase isoforms occur in pressure-overloaded heart in large animals as well as rodents.

Analysis of Variance↗
PubMedDate not supplied

Isoniazid-induced pure red cell aplasia.

The clinical courses of four individuals with pure red cell aplasia associated with isoniazid use are described. Erythroblastopenia in these individuals resolved following cessation of this antituberculous therapy. A clonal assay system that quantitates erythroid precursor cells was used to investigate the pathogenesis of the red cell aplasia in three of the patients. Using this technique, however, we were unsuccessful in demonstrating an inhibitory effect of acute phase serum, isoniazid or a combination of the two on erythroid colony formation. We conclude that isoniazid usage alone appears to be associated with a readily reversible form of acquired pure red cell aplasia. In addition, the results of our in vitro studies emphasize the limitations of bone marrow culture systems when used to implicate offending drugs in the production of drug related cytopenias.

Adult↗
PubMedDate not supplied

Hospital cardiology, cardiac surgery program reported.

In the summer of 1986, at the request of Dr. Benz, the Academy surveyed 600 hospital-based members on their cardiology and cardiac surgery programs. Of the 184 respondents, 103 either had both programs or planned to have them by mid-1987. In this article, Dr. Benz reports the findings of the survey.

Cardiology↗