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Biomedical subjects

J Bernstein

Publications and source records attributed to J Bernstein.

At least 181 records · Page 10Linked to original sources
PubMed1987

The effect of nicotinic acid on the depressant action of ethanol and pentobarbital.

The effect of nicotinic acid (NA) on sleeping time induced by a single dose of ethanol or pentobarbital was studied in rats. It was found that sleeping time was markedly reduced by NA in a dose-dependent manner. The effect was observed when NA was administered 10 min before or after ethanol or pentobarbital, but not when given 60 min in advance. NA did not affect the rate of ethanol elimination measured up to 5 hr after ethanol administration. Rats pretreated with NA 60 min before ethanol slept longer than controls. This latter effect was not observed with pentobarbital. These observations, together with the known lack of effect of high liver NAD+ levels on ethanol metabolism and the rather stable NAD+ concentration in brain cells, suggest that the effect of NA on sleeping time is not mediated by an increase in ethanol metabolism in liver or by NAD+ or NAD+-dependent reactions in brain. Our results are consistent with a direct action of NA, or some rapidly formed derivative, on a structure or process associated with brain cell functions or membranes.

Animals↗
PubMed1987

Effects of ethanol on calcium transport across the liver cell plasma membrane.

The effect of ethanol on calcium transport by the liver cell was studied by using a rat liver slice preparation. Ethanol was shown to decrease by about 30% the rate constant for 45Ca efflux from the intracellular compartment. This inhibitory effect of ethanol was not observed in the absence of Ca2+ or Na+ from the incubation medium. Ethanol was also shown to greatly increase non-insulin calcium uptake by liver slices. This effect of ethanol appeared to be dose dependent and was not observed in the absence of Na+ from the incubation medium. The ability of ethanol to increase calcium uptake by the hepatocyte was completely blocked by 1 mM Amiloride. Amiloride, however, did not affect the increased entry of either Na+ or Ca2+ produced by 10 mM Ouabain, a specific inhibitor of the sodium pump. Carbon tetrachloride (CCl4), a well known hepatotoxin, also increased calcium uptake by the hepatocyte. Amiloride, however, was not able to block the CCl4-induced calcium uptake. These results suggest that ethanol activates a Na+ entry pathway, probably represented by a Na+/H+ exchanger, which in turn stimulates an entry of Ca2+ through a Na+/Ca2+ exchange mechanism located in the plasma membrane of the hepatocyte.

Amiloride↗
PubMed1986

Early weight-change patterns in neonatal abstinence.

Early weight-change patterns were studied in 101 passively addicted neonates. Newborns showing mild abstinence and not requiring pharmacologic treatment lost an average of 4.0% of birth weight, reached a weight nadir on day 3, and regained birth weight by days 7 to 8. Newborns treated with either paregoric or phenobarbital for more severe signs of abstinence lost an average of 6.3% of birth weight, reached a nadir on days 6 to 7, and regained birth weight only by days 13 to 14. Despite comparable birth weights and energy intakes, treated newborns weighed 95 g less than untreated neonates on day 10 when the untreated neonates were discharged. In light of abnormal early weight-change patterns seen with more severe abstinence, both strict control of abstinence and provision of additional individualized nutritional support seem warranted.

Birth Weight↗
PubMed1986

Sensitization of T lymphocytes to thyroid antigen in autoimmune thyroid disease as demonstrated by the monocyte procoagulant activity test.

Monocyte procoagulant activity (PCA) production has been reported to have a close relation to cell-mediated immunity (CMI), and the collaboration of T lymphocytes is necessary to induce PCA. Antigen-specific sensitization of lymphocytes in patients with Graves' disease (GD) and Hashimoto's thyroiditis (HT) has been demonstrated by means of the production of cell-bound PCA by monocytes following antigen stimulation of whole peripheral blood mononuclear cells (PBM). These cells, obtained from both normal subjects and patients with autoimmune thyroid diseases, produced significant amounts of PCA with non-specific lectin, concanavalin A (Con A) stimulation; however, there was no significant difference between the two groups, suggesting that Con A stimulated T cells induced monocyte PCA nonspecifically. Peripheral mononuclear cells from patients with autoimmune thyroid diseases produced significantly greater amounts of PCA than PBM from normal subjects when stimulated with solubilized and IgG-free thyroid antigen. On the other hand, liver antigen did not induce significant amounts of PCA production in PBM from either normal subjects or patients. Significantly larger amounts of PCA were produced by PBM from patients following thyroid antigen stimulation than with liver antigen stimulation. Although monocytes were the major source of PCA, T cells were necessary to induce PCA in monocytes with thyroid antigen and Con A stimulation. Elimination of lymphocyte subsets in PBM from patients by negative selection (using monoclonal antibodies and complement) suggested that the collaboration of T lymphocytes, especially helper/inducer (T4+) T cells, was necessary to produce PCA with thyroid antigen stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Identifying with the patient: an intensive programme for medical students.

An intensive programme called 'Hospitalization Week' was developed at the medical school of the Ben-Gurion University of the Negev in Israel. The main goal of the programme is to give first-year medical students an opportunity to understand the complexity of the needs and problems of hospitalized patients. To achieve this goal each student accompanies two patients from their arrival at the emergency room throughout their stay in the hospital. The goals and methods of the programme are described and evaluated.

Consumer Behavior↗
PubMed1986

Control of hyperprolactinemia with pergolide.

Ten patients with clinical, laboratory and radiographic evidence compatible with the diagnosis of prolactinoma were treated with two dopamine agonists. One group (N = 6) took bromocriptine and the other group (N = 4) used pergolide, a longer-acting agent. Both medications were found to reduce prolactin levels significantly from baseline, but an oscillatory pattern with significant fluctuation was seen in the mean prolactin levels in the patients taking bromocriptine. Three patients did not achieve euprolactinemia on bromocriptine, 2.5 mg qid, the maximum dose used in this study. All of the study group taking pergolide became euprolactinemic rapidly; no more than a single dose of 100 micrograms/day was required. Tumor reduction was noted in two patients taking bromocriptine and two taking pergolide. The duration of side effects was shorter and compliance was improved on pergolide therapy.

Bromocriptine↗
PubMed1986

Minimal renal amyloidosis with nephrotic syndrome.

Two patients older than age 50 years had minimal amyloidosis in association with the nephrotic syndrome. The amyloid deposits in each case were so inconspicuous as to have been initially overlooked, and both biopsy specimens were thought to show minimal glomerular changes. A few, widely scattered, silver-positive, epimembranous spicules were found on reexamination by light microscopy, and Congo red and thioflavin T stains and electron microscopy confirmed the presence of small glomerular amyloid deposits. Both patients have since died of renal failure. In our series of biopsy specimens, amyloidosis was found in 14.2% of patients older than age 50 years presenting with nephrotic syndrome or severe proteinuria, over 1 1/2 times the frequency of minimal-change nephrotic syndrome. We therefore urge careful examination for amyloid deposits of all kidney biopsy specimens with the appearance of minimal-change nephrotic syndrome in older patients. Fluorescence microscopy of Congo red- and thioflavin T-stained sections is very helpful in the detection of small deposits.

Amyloidosis↗
PubMed1986

The renal lesions of tuberous sclerosis.

Renal involvement in the tuberous sclerosis complex includes angiomyolipomas, cysts, and carcinomas. Angiomyolipomas, despite a sometimes frightening histopathologic appearance, are benign. Cystic disease, apparently resulting from tubular epithelial hyperplasia, causes hypertension and renal insufficiency, progressing to end-stage renal disease. The same epithelial hyperplasia predisposes to renal carcinoma.

Adolescent↗
PubMed1986

Mechanical responses of developing Fisher rat heart. Effects of steroid hormone.

Age-dependent changes in the mechanical responses of developing Fisher rat heart during the first three postnatal weeks were studied in relation to the hypothesis that the abnormality observed in the mechanical responses of the rat heart might be calcium related. Therefore the effect of frequency of stimulation as well as the response to calcium, epinephrine and ouabain on hearts of untreated and cortisol-treated rats was compared. The positive force-frequency response observed in fetal rat heart reverted to a highly negative response by the 12th to 14th postnatal day. The biphasic mechanical responses directly paralleled reported changes in circulating glucocorticoid levels in developing rat. The force-frequency response was maximally negative when the circulating levels of glucocorticoids were lowest. The reversion of the negative force-frequency responses coincided with a gradual increase reported in the circulating levels of glucocorticoids. The negative force-frequency response was absent in the cortisol-treated developing rat heart and a definite positive pattern was observed as the rats developed. A high sensitivity to free calcium concentration, seen in control fetal and and newborn hearts, diminished after the second postnatal week. By the third postnatal week, the sensitivity to high extracellular calcium concentrations was significantly reduced. The sensitivity to calcium persisted in the cortisol-treated hearts during the 3 postnatal weeks. Cortisol-treated hearts were more responsive to epinephrine than controls. The abbreviation of time to peak tension, a hallmark of the catecholamine effect, was observed at a younger age in the cortisol-treated hearts. Cortisol-treated hearts were more responsive to the inotropic effects of ouabain than controls. The possible involvement of glucocorticoids in the control of calcium handling elements of the myocardium is discussed.

Animals↗