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Biomedical subjects

S Margolis

Publications and source records attributed to S Margolis.

At least 55 records · Page 3Linked to original sources
PubMed1984

Retinal and optic nerve findings in Goldenhar-Gorlin syndrome.

Involvement of the posterior segment of the eye in Goldenhar-Gorlin syndrome is more common than is generally appreciated. We examined seven patients with this syndrome. Abnormalities included diminished visual acuity, tilted optic disc, optic nerve hypoplasia, tortuous retinal vessels, macular hypoplasia and heterotopia, microphthalmia and anophthalmia. In one case, pathologic study showed agenesis of the optic nerve. It is proposed that retinal, optic nerve and craniofacial abnormalities in this condition may reflect an asynchrony in the migration of the neural crest cells in the early stages of embryonal development.

Adolescent↗
PubMed1984

Intracranial lipomas, hydrocephalus and other CNS anomalies in oculoauriculo-vertebral dysplasia (Goldenhar-Gorlin syndrome).

13 cases of Goldenhar-Gorlin syndrome are presented in which numerous central nervous system anomalies have been found. These include occipital encephalocele, hydrocephalus, aqueductal stenosis, agenesis of corpus callosum, multiple congenital lipomas and many others. Pertinent literature has been reviewed. It is concluded that any part of the central nervous system can be involved in this condition and that careful evaluation is indicated in order to rule out a treatable intracranial anomaly.

Adolescent↗
PubMed1984

Plasma and red blood cell fatty acid composition in children with protein-calorie malnutrition.

Plasma and red cell fatty acids were measured in 44 children with third degree malnutrition: 22 children with marasmus, 11 children with kwashiorkor, and 11 with marasmic kwashiorkor (MK). The presence of edema, dermatosis, hair changes, and hypoalbuminemia were positively correlated with the red cell percentage linoleic acid and negatively correlated with red cell percentage arachidonic acid. Red cell percentage linoleic acid in kwashiorkor was decreased from the control value of 15.3% to 10.9%. In marasmus and MK, there were significantly greater decreases, to 7.7% and 8.0%, respectively. Red cell arachidonic acid in kwashiorkor was significantly (P less than 0.001) decreased to 9.8% (control value of 13.1%) whereas in marasmus there was no significant change. Only one sample, plasma from an infant with marasmus, had any detectable eicosatrienoic acid (20:3,omega 9). Similar changes in fatty acid composition have been reported in infants with acrodermatitis enteropathica, in an infant with biotin deficiency, and in biotin-deficient rats.

8,11,14-Eicosatrienoic Acid↗
PubMed1984

Genital warts and molluscum contagiosum.

Genital warts (condylomata acuminata) and molluscum contagiosum have a significant sexual mode of transmission. They are considered "minor," nonreportable sexually transmitted diseases. As with most lesions, the differential diagnosis must exclude other malignant and nonmalignant diseases. The etiology, diagnosis, management, and epidemiology of both diseases are presented separately.

Anus Neoplasms↗
PubMed1983

OpScan-MIMS. A data network system.

The expansion of a unique system for medical, epidemiological, and laboratory information management is described. The system utilizes an automated, optically scanned data entry mode (OpScan), and a generalized, interactive storage and retrieval software package (MIMS). Aggregate medical, epidemiological, and laboratory information are monitored, with the permission of the locality, via telephone terminals at four sexually transmitted disease clinics. OpScan-MIMS combines an efficient, rapid, and cost-effective method for data entry with a user-friendly computer system that requires no specialized training in computer language.

Centers for Disease Control and Prevention, U.S.↗
PubMed1983

Stimulation of bile acid synthesis by dibutyryl cyclic AMP in isolated rat hepatocytes.

Freshly isolated rat hepatocytes were used to examine the effects of dibutyryl cyclic AMP on the incorporation of 14C-acetate and 14C-cholesterol into bile acids. After an initial lag period, both precursors were incorporated into cholic and chenodeoxycholic acids at a linear rate for the subsequent 60 min. An apparent stimulation of bile acid formation from 14C-acetate by dibutyryl cyclic AMP was complicated by the concomitant inhibition of cholesterol synthesis. In experiments with 14C-cholesterol, dibutyryl cyclic AMP (1 mM) increased the labeled cholic and chenodeoxycholic acids in the medium by 83 and 224%, respectively, but cellular levels of labeled bile acids were unchanged. As a result, the nucleotide stimulated the overall incorporation of 14C-cholesterol into cholic acid by 39% and into chenodeoxycholic acid by 123%. The mean ratio of labeled cholic to chenodeoxycholic acid declined from 55:45 in control cells to 41:59 in cells incubated with dibutyryl cyclic AMP. The results demonstrate that label incorporation can be used to study the regulation of bile acid synthesis in isolated hepatocytes. We propose that dibutyryl cyclic AMP enhanced bile acid production by phosphorylating, and thus stimulating the activity of, cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme in bile acid synthesis.

Acetates↗
PubMed1983

Comparison of glucagon, cAMP, and cGMP effects on lipogenesis in hepatocytes.

Control of lipogenesis by glucagon and cyclic nucleotide derivatives was examined in freshly isolated hepatocytes. [14C]Acetate was incorporated at a linear rate for 2 h into cellular lipids and for at least 6 h into medium lipids. About 80% of the incorporated label was recovered in fatty acids. Incorporation of [1-14C]acetate and 3H2O into cellular and medium lipids was inhibited by glucagon (K50 = 8 X 10(-10) M), dibutyryladenosine 3':5'-cyclic monophosphate (K50 = 7.5 X 10(-8) M), and guanosine 3':5'-cyclic monophosphate and its dibutyryl and 8-bromo derivatives, each with K50 = 2.9 X 10(-6) M. Glucagon (10 nM) reduced incorporation of [14C]acetate and 3H2O into fatty acid by 73 and 52%, respectively, and into cholesterol by 24 and 10%, respectively. When added together to hepatocytes at submaximally inhibitory concentrations, dibutyryl cAMP and dibutyryl cGMP exerted additive effects. However, maximal inhibitory concentrations of both produced the same effect as the addition of either nucleotide alone. Thus, this preparation of rat hepatocytes responded to physiological concentrations of glucagon and low concentrations of dibutyryl cAMP. Cyclic guanosine derivatives inhibited lipogenesis, but 100 times greater concentration was required when compared with dibutyryl cAMP. Dibutyryl cAMP and dibutyryl cGMP did not act synergistically.

Acetates↗
PubMed1983

Hyperinsulinemia of obesity is due to decreased clearance of insulin.

The hyperinsulinemia of obesity could result from a decrease in the metabolic clearance rate of insulin (MCR-I), an increase in the secretory rate of insulin (SR-I), or a combination of both these processes. Because C-peptide and insulin are secreted in an equimolar ratio, the plasma concentrations of C-peptide (C) and insulin (I) are inversely proportional to their rates of metabolic clearance (C/I = MCR-I/MCR-C). We obtained 24-h integrated concentrations (IC) of insulin (IC-I) and C-peptide (IC-C) in 23 obese and 45 nonobese subjects over a period of normal activity and food intake. The IC-I was 69% higher in the obese subjects (P less than 0.0001). A 13% increase in the IC-C (P = 0.04), with a constant rate of C-peptide clearance, indicates a proportionate increase in SR-I. A 33% decrease in the IC-C/IC-I in the obese group (P less than 0.005) reflects a decrease in MCR-I; hence, 75% of the hyperinsulinemia is due to a decrease in the clearance of insulin. Because peripheral MCR-I (pMCR-I) is similar in obese and nonobese subjects, the decrease in MCR-I may be due to a decrease in the hepatic clearance of insulin. This conclusion was supported by our comparison of 24-h IC-C/IC-I ratios in the obese and nonobese subjects. Whereas the 24-h IC-C/IC-I of the nonobese resembled the fasting state, the 24-h IC-C/IC-I of the obese resembled the postprandial state, when insulin removal by the liver is known to be suppressed. These data are consistent with a decreased 24-h hepatic MCR-I (hMCR-I) as the cause of the hyperinsulinemia of obesity.

Adolescent↗
PubMed1983

Effects of drugs and sterols on cholesterol 7 alpha-hydroxylase activity in rat liver microsomes.

This study examined the effects of various drugs and sterols on the rate of 7alpha-hydroxycholesterol synthesis in isolated rat liver microsomes. Cholesterol 7alpha-hydroxylase activity was significantly inhibited by proadifen (98%), metyrapone (67%), and aminoglutethimide (45%) at concentrations of 1 mM and by ascorbic acid (40%) at a concentration of 10 mM. Cimetidine had no significant effect. The activity of cholesterol 7alpha-hydroxylase was also significantly inhibited by 7beta-hydroxycholesterol (38%) and 7-ketocholesterol (35%) at concentrations of 1 micro M, and by 10 micro M 7alpha-hydroxycholesterol (35%), 25alpha-hydroxycholesterol (32%), and 5-cholenic acid-3beta-ol (27%). Two bile acids, cholate and lithocholate, as well as a geometric isomer of cholesterol, coprostanol, had little influence on 7alpha-hydroxylase activity at concentrations of 10 micro M. The inhibitory effect of metyrapone was additive with that of either 7beta-hydroxycholesterol or proadifen; the effects of 7beta-hydroxycholesterol and proadifen were not additive. These results suggest that proadifen and 7beta-hydroxycholesterol interact with the same enzyme site while metyrapone binds at a different location. Proadifen inhibited 7alpha-hydroxylase irreversibly, while kinetic studies demonstrated noncompetitive inhibition by metyrapone (K(I) = 0.55 mM) and competitive inhibition by 7beta-hydroxycholesterol (K(I) = 2.4 micro M). The inhibition of 7alpha-hydroxylase activity by metyrapone and aminoglutethimide, drugs used to manage patients with excessive cortisol production, suggests that such treatment may also alter bile acid synthesis.-Schwartz, M. A., and S. Margolis. Effects of drugs and sterols on cholesterol 7alpha-hydroxylase activity in rat liver microsomes.

Aminoglutethimide↗
PubMed1982

Rat liver cholesterol 7 alpha-hydroxylase. Modulation of enzyme activity by changes in phosphorylation state.

Four lines of evidence presented here suggest that the activity of cholesterol 7 alpha-hydroxylase in rat liver is modulated by changes in its phosphorylation state. 1) Livers were homogenized and microsomes were isolated and washed in the presence of either 50 mM NaCl or 50 mM NaF, the latter an inhibitor of phosphoprotein phosphatases. The 7 alpha-hydroxylase activity of microsomes prepared with NaF was 80% greater than that of microsomes prepared with NaCl. 2) Incubation of 10,000 X g supernatants from rat liver for 20 min at 37 degrees C in the absence of 50 mM KF decreased the activity of microsomal cholesterol 7 alpha-hydroxylase by 52%. No significant change was seen in the presence of KF. 3) 7 alpha-Hydroxylase activity fell by 40% when microsomes were incubated with bacterial alkaline phosphatase compared to incubation of microsomes with phosphatase that was inhibited by phosphate and EDTA. 4) 7 alpha-Hydroxylase activity increased by 22% when phosphatase-treated microsomes were incubated for 40 min at 37 degrees C with 1 mM MgATP, 50 microM cAMP, and 200 units of cAMP-dependent protein kinase.

Alkaline Phosphatase↗
PubMed1982

Pseudohypopyon in Best's vitelliform macular dystrophy.

We examined ten eyes with pseudohypopyon in seven patients with Best's vitelliform macular dystrophy. Fluorescein angiography showed hyperfluorescent defects in the retinal pigment of the superior half of the lesion in all ten eyes. The electro-oculographic findings were abnormal in all four patients who underwent this test. The fluid shifted slightly in two of six patients whose heads were turned to the side for an hour or longer, indicating that the material was probably located between the retinal pigment epithelium and the sensory retina. The volume of the hypopyon increased in one eye.

Adolescent↗
PubMed1982

Integrated concentrations of growth hormone, insulin, C-peptide and prolactin in human obesity.

Twenty-four hour integrated concentrations of growth hormone (IC-GH) were significantly lower in young, obese subjects than in young subjects who were lean. Significant inverse correlations were found between IC-GH and body mass index (BMI) as well as the IC-GH and the 24 hr integrated concentrations of insulin (IC-I) and C-peptide (IC-C) in obese subjects below 30 yr of age. Since IC-GH decreases with age, the effect of obesity on IC-GH could not be demonstrated in the older subjects; a weak inverse correlation (p less than 0.05) between IC-GH and IC-C was found. Prolactin was significantly lower in the older subjects but did not correlate with IC-GH and was similar in lean and obese. Lipid deposition in adipose cells is promoted by high concentrations of insulin as well as low concentrations of growth hormone. We found a significant correlation between the IC-I/IC-GH ratio and BMI of both the young and older subjects. Correlations between these two factors do not necessarily imply a cause and effect relationship. It is plausible, however, that the elevated IC-I/IC-GH of the obese may facilitate their lipid storage and counter their efforts at weight reduction.

Adolescent↗
PubMed1982

Intestinal phospholipase A and triglyceride lipase: localization and effect of fasting.

We investigated the distribution of phospholipase A and triglyceride lipase in the rat small intestine and the effects of heparin and hormones on enzyme release. Phospholipase A activity was 10 times higher in the ileum than in the jejunum; triglyceride lipase activity was threefold higher in the jejunum than in the ileum. Activities of both enzymes were much greater in villus than in crypt cells. The specific activity of phospholipase A was highest in microsomes and least in cytosol. The crude nuclei and brush-border fraction contained 40.5% of total phospholipase A activity; mitochondria contained 33.8%; and microsomes, 17.4%. Phospholipase A activity increased significantly in the distal intestinal mucosa in fasted rats compared with controls. Heparin did not increase the release of phospholipase A by isolated intestinal cells or perfused intestinal vasculature. Thus, the small intestine probably does not contribute significantly to the phospholipase A activity of postheparin plasma. Hormones and cAMP, which inhibit the secretion of phospholipase A and triglyceride lipase from isolated hepatocytes, had no effect on the release of either enzyme from intestinal cells.

Alkaline Phosphatase↗
PubMed1982

Short term improvement in glycemic control utilizing continuous subcutaneous insulin infusion: the effect on 24-hour integrated concentrations of counterregulatory hormones and plasma lipids in insulin-dependent diabetes mellitus.

Eight patients with established insulin-dependent diabetes mellitus were studied before and 2 weeks after the initiation of pumped continuous sc insulin infusion in order to investigate the effect of short term improvement of glycemic control on hormonal and lipid levels. Glycemic control was improved in all patients. Using a constant blood withdrawal pump, accurate 24-h average concentrations, denoted integrated concentrations, were obtained. The mean 24-h integrated concentrations of GH, cortisol, norepinephrine, and epinephrine did not change significantly. The mean fasting triglyceride concentration dropped from 119.1 to 83.4 mg/dl (P less than 0.05). The mean 24-h integrated concentration of plasma triglycerides fell from 132.1 to 101.5 mg/dl (P less than 0.02). Both mean fasting and mean 24-h integrated concentrations of plasma cholesterol were lower after improved control. Short term improvement in glycemic control was associated with a reduction in plasma lipid concentrations, but failed to alter mean 24-h integrated concentrations of the measured counterregulatory hormones.

Adolescent↗
PubMed1982

Estimation of the secretion rate of insulin from the urinary excretion rate of C-peptide. Study in obese and diabetic subjects.

Direct methods for measuring the secretion rate of insulin are too cumbersome for clinical application. Since C-peptide is secreted in an equimolar ratio with insulin and is excreted into the urine, measuring the urinary excretion rate of C-peptide (U-C) could serve as an indicator of its secretion rate (SR-C) if its urinary clearance (UCI-C) is constant and unaffected by plasma C-peptide concentration, body mass, or diabetes. We measured clearance ratios of C-peptide/creatinine (CR) in the fasting state and integrated 0-1, 1-3, and 3-5 h after 100 g of glucose p.o. as well as over a full 24-h in eight obese, eight lean, and six maturity-onset diabetic subjects. CR did not differ significantly when values in the fasting state were compared with those in the postprandial periods and was therefore unaffected by plasma C-peptide concentration. Furthermore, CR was similar in the lean, obese, and diabetic subjects. SR-C, determined as the product of the metabolic clearance rate of C-peptide and its fasting or integrated plasma concentrations, correlated significantly with U-C in all the subjects (r = 0.87, P less than 0.0001). The correlation of U-C with SR-C in the diabetic subjects alone was also significant (r = 0.88, P less than 0.0001). In conclusion, our data support the use of U-C as an indirect measure of SR-C and therefore of SR-I.

Adult↗
PubMed1981

Correlation of urinary excretion of C-peptide with the integrated concentration and secretion rate of insulin.

The secretion rate of insulin (SR-I) of 50 normal subjects was calculated from the 24-h integrated concentration of insulin (IC-I), the peripheral metabolic clearance of insulin (pMCR-I), and the mean fractional hepatic insulin extraction (fhMCR-I) that was derived from our data. fhMCR-I was determined as the difference in the molar secretory rate of C-peptide (SR-C) and the molar peripheral clearance of insulin (pMCR-I x IC-I) divided by SR-C. The IC-I in our 50 subjects was 1.19 +/- 0.38 ng/ml and the IC-C was 2.93 +/- 0.58 ng/ml. Based on these data, the fhMCR-I was 0.40 and the Sr-I was estimated to be 54.8 +/- 18.0 U/24 h. The 24-h urinary C-peptide excretion (U-C), 44.9 +/- 20.4 micrograms/24 h, had a statistically significant correlation with SR-I (r = 0.838, P less than 0.0001), while the IC-I correlated significantly with the 24-h urinary C-peptide/g of creatinine (r = 0.838, P less than 0.0001). The U-C may thus serve as a practical method for estimating the SR-I.

Adolescent↗
PubMed1981

Serum hormones and lipoproteins in benign breast disease.

Seventeen young women with clinically confirmed mammary dysplasia and six age-matched controls were treated with alpha-tocopherol. Serum samples collected during the luteal phase of each woman at monthly intervals for the 4-month duration of the study were analyzed for serum luteinizing hormone, follicle-stimulating hormone, and prolactin concentrations by radioimmunoassay and for lipoprotein levels by a combination of precipitation, ultracentrifugation, and enzymatic techniques. Fifteen patients showed objective and subjective remission from disease. While prolactin levels did not change significantly, elevated levels of luteinizing and follicle-stimulating hormones were decreased to normal levels. Ratios of serum cholesterol to high-density lipoprotein cholesterol decreased; high-density lipoprotein and free cholesterol associated with low-density lipoproteins increased as a result of therapy. The results suggest that alpha-tocopherol may serve as an effective agent not only to treat patients with benign breast disease but also to normalize abnormal hormone and lipid levels in subjects at high risk for breast cancer.

Breast Diseases↗