PubMed Health⌕ Search

Biomedical subjects

O Shalev

Publications and source records attributed to O Shalev.

At least 73 records · Page 4Linked to original sources

Erythrocyte 22Na+ influx in hypertension.

We assessed 22Na+ uptake by erythrocytes (RBC) from 38 individuals with essential hypertension and 37 healthy controls. All subjects were male, white, non-obese and with normal renal function, obviating sex, race, hormonal, ponderal and renal factors known to influence RBC Na+ handling. The mean +/- sem 22Na+ uptake of the patients was 284 +/- 16 mumole/liter RBC/hour while that of normal controls was 249 +/- 11 mumole/liter RBC/hour; although the difference reached borderline significance, individual values showed considerable overlap. Consequently, in our population, RBC 22Na+ uptake is not a reliable marker for essential hypertension. We believe that previous studies should be reassessed with regard to patients' characteristics and future studies employ rigorous criteria in selection of subjects.

Adult↗

Improved prognosis during long-term treatment with beta-blockers after myocardial infarction: analysis of randomized trials and pooling of results.

We reviewed 14 randomized controlled trials that involved long-term treatment of patients after myocardial infarction with beta-blockers. Studies in which randomization was carried out at the time of hospital admission were excluded because of a very high rate of early withdrawal before hospital discharge. Seven studies were found methodologically acceptable, and their results were analyzed according to the "intention-to-treat" principle to avoid bias caused by late withdrawals. Although only two of the trials found a significant reduction in total deaths in the beta-blocker groups, pooling the data from all seven studies showed a highly significant treatment benefit (p less than 0.001). The best estimate of the magnitude of the reduction in mortality rates is 26%. Pooling of the data revealed similarly significant reductions in the rates of reinfarction (p less than 0.001) and sudden death (p less than 0.001).

Adrenergic beta-Antagonists↗

Impaired erythrocyte calcium homeostasis in beta-thalassemia.

Intracellular calcium (Ca) concentration in erythrocytes (RBCs) is controlled by a low passive influx through a relatively impermeable membrane and by active efflux catalyzed by Ca2+,Mg2+-ATPase. Since precipitation of alpha-globin chains in thalassemic RBCs may interfere with normal membrane function, we studied the RBC intracellular Ca content and the RBC membrane Ca2+,Mg2+-ATPase activity in two groups of patients with nonsplenectomized (n = 9) and splenectomized (n = 9) beta-thalassemia intermedia and in two groups of matched controls. The mean +/- SD Ca concentration in the nonsplenectomized (n = 12) and splenectomized (n = 6) controls were 6.1 +/- 6.0 and 5.8 +/- 3.4 mumol Ca per liter of RBCs, respectively, compared with 26.0 +/- 7.6 (P less than .001) and 85 +/- 24.4 (P less than .001) in the nonsplenectomized and splenectomized thalassemia patients, respectively. The mean +/- SD Ca2+,Mg2+-ATPase activity in the eight nonsplenectomized patients was 0.77 +/- 0.58 mumol inorganic phosphate (Pi) per milligram of protein per hour compared with 0.66 +/- 0.41 in the controls (P = NS). Similar values were obtained for the splenectomized patients and their controls. No correlation was found between either the intracellular Ca content or the Ca2+,Mg2+-ATPase activity with the peripheral nucleated RBC count. These findings suggest that there is a major defect in the membrane of the thalassemic RBC leading to an increased Ca content that is more pronounced in splenectomized patients.

Calcium↗

Myelofibrosis in young adults.

3 young adults with myelofibrosis, a rare disease in this age-group, are presented. Their clinical course was distinguished by a virtually asymptomatic state at time of diagnosis and a stable, or very slowly progressive course over a 4- to 5-year follow-up. Myelofibrosis in young adults may pursue a more benign course than that usually noted in older populations.

Adult↗

Comparison of the antianginal effectiveness of nifedipine, verapamil, and isosorbide dinitrate in patients receiving propranolol: a double-blind study.

Ten men with stable angina not fully relieved by optimal doses of propranolol were given on each of four mornings a single dose of 10 mg nifedipine, 120 mg verapamil, isosorbide dinitrate (5 to 30 mg, previously titrated to lower systolic blood pressure by 15 to 20 mm Hg), or placebo, in double-blind fashion. Bicycle exercise to angina was performed hourly for 8 hr thereafter. All three vasodilators increased exercise time by at least 50% by the first hour (p less than .001), with a gradually diminishing effect persisting for 6 to 8 hr (p less than .01). Although for the group there were no differences in magnitude and duration of effect among the three drugs, in five of the individual patients there were important differences in response favoring one or another vasodilator. We conclude that nifedipine, verapamil, and isosorbide dinitrate are equally effective and reasonably long-acting antianginal supplements to propranolol, although some patients may benefit more from one than another of the three.

Adult↗

Alterations in structure, function, and Ca++ content of thalassemic red blood cells.

Dodge ghosts and their Triton extracted cytoskeletons (TS) were obtained from RBC of splenectomized (spx) and non-splenectomized (non-spx) patients with beta thalassemia intermedia. No major abnormalities were seen in the polypeptide pattern of Dodge ghosts of the thalassemic patients apart from increased globin content in the spx patients (P = 0.004). There was also a large increase of globin content in the TS of both spx and non-spx patients, while the spectrin content of the TS was markedly decreased from 22 +/- 2.8% in the spx patients compared to 39 +/- 2% in the controls (P = 0.006). At least part of the globin was not found at the normal band 3-binding site. The mean Ca++ content in spx and non-spx controls was approximately 6.0 micromoles ca/liter RBC, as compared to 26 +/- 7.6 (P less than 0.001) in the non-spx and 85 +/- 24 in the spx thalassemic patients (P less than 0.001). (Ca++Mg++)-ATPase activity was in the same range in RBC of patients and controls. Membrane protein phosphorylation was examined by incubation of intact cells with (32P)Pi. There was decreased labeling of several protein bands in thalassemic RBC which are labeled in normal RBC. New phosphorylation peptides also appeared. On the other hand, there were no major differences in the phosphorylation of isolated membranes including phosphorability of spectrin. The possible etiology and consequences of the newly described RBC membrane changes in thalassemia is discussed.

Blood Proteins↗

Methyldopa-induced immune hemolytic anemia and chronic active hepatitis.

Immune hemolytic anemia and chronic active hepatitis developed concurrently in a 76-year-old man after prolonged therapy with methyldopa. Both complications disappeared following cessation of treatment with the offending drug and a short course of a high-dose corticosteroid (prednisone). Inhibition of T-suppressor lymphocyte function by methyldopa may be instrumental in the emergence of autoimmune complications following usage of the drug.

Aged↗

Additive antianginal effect of verapamil in patients receiving propranolol.

Ten men with stable angina pectoris not fully relieved by optimal doses of propranolol (mean 218 mg daily) were given a single oral dose of 120 mg verapamil or a placebo on alternate mornings; the order of treatment was double blind. Patients had trained in a protocol that precipitated angina after three to six minutes of exercise on a bicycle ergometer. On test days, and with continued propranolol treatment, bicycle exercise was performed just before the administration of verapamil or placebo and hourly thereafter for eight hours. Mean exercise tolerance was 118 seconds greater one hour after verapamil than one hour after placebo (p <0.001), and a significant though somewhat diminished difference of 66 seconds was still present at six hours (p <0.01). Verapamil lowered resting systolic blood pressure by 12 mm Hg (p <0.01) without changing heart rate. None of the 10 patients showed adverse effects from the verapamil-propranolol combination.The results of this study suggest that verapamil is a highly effective antianginal supplement to propranolol.

Angina Pectoris↗

Tumour of the nose as a presenting feature of leukaemia.

A skin nodule on the external nose, as a presenting feature of acute myeloid leukemia, is described. The child presented with a lesion on the tip of the nose together with the clinical and haematologic features of leukaemia. The histological finding of the nodule was found to be a characteristic leukaemia cutis with leukaemia cell infiltrate in the skin. Epistaxis and external ear infection were also additional features of E.N.T. system involvement, as we find in other leukaemic patients. Since starting chemotherapy the patient has been well, in complete remission, and the lesion on the nose has almost disappeared.

Adolescent↗

The additive antianginal action of oral nifedipine in patients receiving propranolol: magnitude and duration of effect.

Ten men with stable angina not completely relieved by full doses of propranolol (mean 218 mg/day) were administered an oral dose of 10 mg of nifedipine or placebo on alternate mornings in a double-blind fashion. Patients had been trained in a protocol that precipitated angina after 3-6 minutes of bicycle exercise. On test days, with propranolol continued, bicycle exercise to angina or fatigue was performed before nifedipine or placebo administration, and hourly thereafter for 8 hours. Mean exercise duration was greater 1 hour after nifedipine than after placebo by 123 seconds (372 +/- 21 vs 249 +/- 16 seconds, p less than 0.001). By the fifth hour, the increase in exercise time was reduced to 93 seconds (p less than 0.001), and a significant, though further diminished, difference of 57 seconds was still present at 8 hours (p less than 0.01). Nifedipine lowered resting systolic blood pressure by 20 mm Hg (p less than 0.001) without appreciably changing heart rate. We conclude that nifedipine is a very effective and reasonably long-acting antianginal supplement to propranolol.

Administration, Oral↗