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Biomedical subjects

S Margolis

Publications and source records attributed to S Margolis.

At least 19 recordsLinked to original sources

Early predictors of career achievement in academic medicine.

OBJECTIVE: To identify early personal and scholastic factors that predict academic career choice and long-term career achievement among academic physicians. DESIGN: A longitudinal cohort study. PARTICIPANTS: Nine hundred forty-four male physicians who graduated from The Johns Hopkins University School of Medicine, Baltimore, MD, from 1948 through 1964. OUTCOME MEASURES: Career achievement outcomes included attained faculty rank in 1990 and the number of citations (20 to 24 years after graduation) to published work. RESULTS: Of the 944 physicians, 424 (45%) had chosen academic careers. Scholastic performance and research experience in medical school were independently associated with having chosen an academic career (P less than .001). Among academicians, higher attained rank in 1990 was independently associated with the following: (1) membership in Alpha Omega Alpha (relative risk [RR] = 4.94, P = .0001); (2) rank in the top third of the graduating class (RR = 2.68, P = .01); and (3) research experience in medical school (RR = 3.11, P = .0001). These three factors were also independently associated with more citations to participants' published work (P less than .05). CONCLUSION: These data suggest that scholastic performance and research experience during medical school predict career achievement in academic medicine over 20 years in the future.

Achievement

Effects of pravastatin, a new HMG-CoA reductase inhibitor, on vitamin D synthesis in man.

The HMG-CoA reductase inhibitors, a new class of lipid-lowering agents being used with increasing frequency, inhibit synthesis of cholesterol in vivo. Thus, one potential side effect of these drugs is alteration of other metabolic pathways requiring intermediates in the cholesterol biosynthetic pathway. We hypothesized that pravastatin, a new HMG-CoA reductase inhibitor, may impair vitamin D3 synthesis in the skin and alter mineral homeostasis by diminishing the availability of vitamin D precursors. Basal serum levels of calcium, phosphorus, parathyroid hormone (PTH), vitamin D3, and 1,25-dihydroxyvitamin D were measured, and dietary intakes of calcium and vitamin D were calculated in a control hypercholesterolemic group and an experimental group treated with pravastatin 10, 20, and/or 40 mg orally twice daily for at least 3 months. Basal parameters of mineral metabolism were similar in the two groups. To assess the capacity of the skin to synthesize vitamin D3 and as an indirect measure of its precursors, all subjects received whole body ultraviolet irradiation (UVI) in a phototherapy chamber for varying time intervals. Subjects in both groups showed significant (P less than .001) dose-dependent increases in vitamin D3 production after equivalent UVI exposures. However, for equivalent UVI exposure, the serum vitamin D3 response was identical in controls versus pravastatin-treated subjects. We conclude that hypercholesterolemic patients have normal mineral metabolism and the use of pravastatin at these doses for up to 3 months does not alter vitamin D3 synthesis in the skin.

Adult

Bilateral optic disc neovascularization in association with retinitis pigmentosa.

Bilateral neovascularization of the optic disc developed in a 16-year-old Hispanic girl with retinitis pigmentosa. The neovascularization regressed in both eyes over 1 year without treatment. Ocular and systemic evaluation failed to reveal a recognized cause for the neovascularization. To our knowledge this is only the third case reported of this unusual association.

Adolescent

Efficacy and safety of pravastatin in patients with primary hypercholesterolemia. I. A dose-response study.

This multicenter, double-blind, placebo-controlled, dose-response study was conducted in patients with primary hypercholesterolemia to examine the effects of pravastatin, a selective inhibitor of HMG-CoA reductase, on plasma lipids and lipoproteins. A total of 306 patients on cholesterol-lowering diets received twice daily doses of 5 mg, 10 mg, 20 mg pravastatin, or placebo for 12 weeks. Marked reductions in low density lipoprotein (LDL) cholesterol and total cholesterol were observed after 1 week of treatment; maximum lipid-lowering effects occurred at 4 weeks and were sustained for the duration of the trial. At week 12, pravastatin treatment resulted in dose-dependent mean reductions from baseline in LDL cholesterol of 17.5%, 22.9%, and 30.8% for the 3 doses tested (P less than or equal to 0001 compared with baseline and placebo). The reduction in LDL cholesterol was log-linear with respect to dose; each doubling of dose reduced LDL cholesterol an additional 6.5%. Dose-dependent reductions in total cholesterol from 12.9% to 23.3% also occurred (P less than or equal to 0.001). Triglycerides decreased by as 15.4% (P less than or equal to 0.001) and high-density lipoprotein (HDL) cholesterol increased approximately 7% (P less than or equal to 0.01), but these effects were not dose-dependent. No patient receiving pravastatin was discontinued during the 12-week trial. Transient episodes of rash and headache occurred. Slight increases in mean serum levels of ASAT and ALAT occurred, and 2% of both placebo- and pravastatin-treated patients reported myalgia although there was no clinically significant elevation of creatine kinase. These data indicate that pravastatin favorably affects all lipid parameters and is well tolerated.

Anticholesteremic Agents

Nutritional status and growth in juvenile rheumatoid arthritis.

The specific cause of short stature in juvenile rheumatoid arthritis (JRA) is unknown. One hypothesis links altered growth to inadequate dietary intake. In this study, nutritional status was assessed in 34 children with JRA (8 with systemic JRA, 14 with polyarticular JRA, and 12 with pauciarticular JRA) and 9 healthy controls using 3-day diet records, anthropometrics, and biochemical analyses. Differences in growth were found among the three types of JRA. One third of all subjects were at or below the 10th percentile in height for age (these being predominantly among the systemic and polyarticular groups). With few exceptions, the mean dietary intake for calories and essential nutrients was found to be adequate for each of the three groups. However, more than half of those with systemic JRA reportedly consumed less than the recommended caloric intake for their age and weight. No significant correlations were found linking dietary intake to growth percentiles in any of the groups studied. Biochemical abnormalities were found among the systemic and polyarticular groups. These abnormalities included low plasma levels of vitamins A and C, proteins (albumin, prealbumin, and retinol binding protein) and zinc; and increased levels of copper and glutathione peroxidase activity. Plasma selenium and vitamin E levels were unchanged. The discrepancy between intake and certain circulating nutrient levels may reflect alterations in the requirements, absorption, or use of these nutrients in the presence of chronic inflammation.

Adolescent

The golden tapetal sheen reflex in retinal disease.

A mother and son with dominant cone dystrophy manifested the retinal reflexes seen in Oguchi's disease (mother) and the carrier female of X-linked retinitis pigmentosa (son). Another patient with cone dystrophy (simplex) showed localized areas of a golden reflex in each eye. A patient with juvenile macular dystrophy exhibited a diffuse golden-orange reflex throughout the posterior pole. The latter two patients did not have the Mizuo phenomenon.

Adult

Nutritional management of plasma lipid disorders.

Prevention of vascular disease and acute pancreatitis is the goal of hyperlipidemia treatment. The risk of coronary heart disease (CHD) increases with increasing plasma cholesterol levels because low-density lipoprotein (LDL), the major carrier of cholesterol in the plasma, is atherogenic. High-density lipoprotein (HDL), especially the HDL2 subfraction, protects against CHD. Hypertriglyceridemia, although not an independent risk factor for CHD, is generally accompanied by low HDL cholesterol (HDLch), which may predispose to CHD. Reducing plasma LDL and raising HDL levels are thus goals in preventing CHD. Serum LDL levels may be lowered by reducing saturated fat and cholesterol intake; weight loss may decrease LDL but is more effective in lowering plasma triglycerides and raising HDLch. The percent of total calories from polyunsaturated, monounsaturated, and saturated fats should be less than 10%, up to 10-15%, and less than 10%, respectively. High cholesterol intake increases the flux of cholesterol, which may be harmful to arterial walls, but beyond a certain point does not increase plasma cholesterol levels. Some diets change the composition rather than the level of LDL and apoproteins. Weight reduction and maintenance are the most effective dietary measures to lower plasma triglycerides; omega-3 fatty acids (fish oils) have shown promise in reducing triglyceride but not cholesterol levels. Substitution of starch for sugar lowered triglyceride levels toward normal in hypertriglyceridemia patients. Fasting triglyceride levels rise in all individuals fed high-carbohydrate diets, but the high levels persist in hypertriglyceridemia patients. Weight loss, cessation of cigarette smoking, increased physical activity, good control of diabetes, and moderate alcohol use all raise HDLch levels. Vitamin E deficiency causes neurological sequelae in children with severe malabsorption problems due to abetalipoproteinemia or cholestatic liver disease.

Acute Disease

Improved glycemic control lowers plasma apoprotein E and triglyceride levels following ingestion of a fat load in insulin-dependent diabetic subjects.

To assess the effect of glycemic control on triglyceride (TG) and apoprotein E (apo E) metabolism, plasma levels of TG and apo E were studied in nine nonobese subjects with insulin-dependent diabetes mellitus (IDDM) following acute ingestion of polyunsaturated fat. Each subject was studied twice: before and after ten days of continuous subcutaneous insulin infusion (CSII). Each subject ingested identical meals on both study days. Plasma glucose was determined in all patients before and two hours after each meal and at 3 AM, and a mean value was calculated for each patient. CSII reduced mean plasma glucose from 205 to 113 mg/dL (P less than .005, paired t test); there was no change in the total daily insulin dose. Plasma TG and apo E levels were measured before and 3.5, 5, and 7 hours after a breakfast which contained 50 g of fish oil (five subjects) or vegetable oil (four subjects). A repeated-measures ANOVA was performed to assess the effects of the following three factors on plasma TG and apoE levels: type of oil ingested (Oil, factor A), glycemic control (Glycemic control, factor B), and the response to fat ingestion over time (Times, factor C). Plasma levels of both apo E and TG increased significantly after fat ingestion (F test, ANOVA, P less than .005 and P less than .001, respectively). Glycemic control significantly reduced the rise in both apo E and TG levels (P less than .005 and P less than .05, respectively). The effect of the type of oil and the interactions tested (AB, AC, BC, ABC) were not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Effect of improved glycemic control on the response of plasma triglycerides to ingestion of a saturated fat load in normotriglyceridemic and hypertriglyceridemic diabetic subjects.

This study tests the hypothesis that improved glycemic control decreases the postprandial plasma triglyceride (TG) response to ingestion of a saturated fat load. Fifteen normotriglyceridemic subjects with insulin-dependent diabetes mellitus (IDDM, group I) and six hypertriglyceridemic subjects with non-insulin-dependent diabetes mellitus (NIDDM, group II) were studied. Each subject was studied before and after 12 days of continuous subcutaneous insulin infusion (CSII). Each subject ingested identical meals on both study days. Plasma glucose was determined in all patients before and two hours after each meal and at 3 AM, and a mean value was calculated for each patient. CSII reduced mean plasma glucose from 252 to 140 mg/dL in group I, and from 209 to 120 mg/dL in group II (P less than .001 in both groups, paired t test). Plasma TG levels were measured before and 1.5, 3, 4.5, 6, and 7.5 hours after a breakfast which contained 50 g of mostly saturated fat. A repeated-measures ANOVA was performed to assess the effects of glycemic control (factor A) and TG response (factor B) to fat ingestion. In both groups plasma TG levels increased significantly after fat ingestion (P less than .001), and were significantly reduced during improved glycemic control (P less than .001). The reduction was observed in 14 of 15 patients in group I and in all patients in group II. In group I the lowering of the postprandial plasma TG levels after CSII was secondary to a decrease in the fasting plasma TG levels, as shown by the unchanged mean percent TG elevation over the baseline.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

The social image of smokeless tobacco use in three different types of teenagers.

The current study used an unobtrusive methodology to describe the social image associated with smokeless tobacco use and with cigarette smoking in three "types" of teenage models--an athlete, a cowboy, and an average teenager. As in previous research, the social image associated with smokeless tobacco use was more positive than that associated with cigarette smoking, suggesting that adopting smokeless tobacco use may have perceived social image benefits for adolescent males. The image conveyed by smokeless tobacco use was similar across the three different types of adolescent. Relations between social image factors and tobacco use behavior were examined, and implications for tobacco use prevention are discussed.

Adolescent

Intracardiac extension of intravenous leiomyomatosis.

A 42-year-old woman was found to have intravenous leiomyomatosis of the uterus with extension into the inferior vena cava and right atrium. Intravenous leiomyomatosis is a rare neoplastic disease characterized by invasion of venous channels by a benign smooth muscle tumor arising either from the wall of a vessel or from a uterine myoma. Intracardiac extension is often initially misdiagnosed as a right atrial myxoma and may cause death by mechanical obstruction. The diagnosis of intravenous leiomyomatosis should be considered in young women with cardiac symptoms associated with a right atrial mass who also have a pelvic mass or who have previously undergone hysterectomy because of leiomyoma uteri.

Adult

Variable expressivity in fundus albipunctatus.

A healthy, 14-year-old girl presented with nyctalopia, good vision, and multiple, irregular, yellowish lesions of the fundus. Dark adaptometry showed prolonged cone and rod branches, elevated thresholds, and the cone-rod transition occurring after 50 minutes in darkness. Her scotopic electroretinogram (ERG) b-wave attained normal amplitudes after 45 minutes of dark adaptation. The half-time for regeneration of rhodopsin after an extensive bleach was 16 minutes, four times longer than normal, and the maximum density difference measured by fundus reflectometry was at the lower limit of the normal range. Although photopigment kinetics were significantly faster than observed in other reported cases of fundus albipunctatus, it appears likely that there is a wide spectrum of functional and funduscopic abnormalities in this disorder. However, fundus appearance, adaptometric findings, and rhodopsin determinations serve to distinguish fundus albipunctatus from other flecked retina diseases.

Adolescent