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Biomedical subjects

N Barzilai

Publications and source records attributed to N Barzilai.

82 records · Page 5Linked to original sources

Activated interferon system in healthy homosexual men.

More than 50% of a group of healthy homosexuals in Israel were found to have an activated interferon (IFN) system as evidenced by markedly elevated blood IFN levels, increased in vitro production of IFN by unstimulated peripheral blood mononuclear cells and HuIFN-alpha and HuIFN-gamma production by appropriately stimulated cells, and a surprisingly high incidence of an antiviral state of cells. This pattern resembles that found in persons with acute viral illness, and is unlike that found in normal healthy controls. The type of IFN in the blood was found to be unusual in that it was mainly HuIFN-alpha, pH 2-labile, a type of IFN found in certain collagen diseases as well as in homosexual men suffering from Kaposi's sarcoma or lymphadenopathy. Natural killer (NK) cytotoxic activity was found to be somewhat lower than that found in normal controls, although no correlation was found between blood IFN levels and NK activity. Mean (2'-5')-oligoisoadenylate synthetase levels in cell extracts were intermediate between normal controls and patients with viral illness. Likewise no correlation was found between enzyme levels and blood IFN levels. The highly activated IFN system found in certain homosexuals, as well as the increased spontaneous production of IFN by unstimulated mononuclear cells, suggest the possibility of the presence of a virus, active or latent, in these individuals. This virus could be a retrovirus such as HTLV-III or LAV which have recently been isolated from AIDS patients. The special type of IFN present could be the response to a novel virus in an unusual situation. On the basis of recent reports, we speculate that homosexuals with highly activated IFN systems who produce pH 2-labile HuIFN-alpha could be at increased risk for developing AIDS.

Acquired Immunodeficiency Syndrome↗

Insulin resistance in Cushing's syndrome.

Insulin resistance is well established in Cushing's syndrome, but its mechanisms are not completely understood. We performed the euglycemic insulin clamp technique on four patients with Cushing's syndrome, five obese patients and five normal volunteers, in order to determine the role of impairments in insulin responsiveness and insulin clearance in hypercorticism and obesity. Insulin was infused at 0.3, 1, 3 and 10 mU/kg/min, and steady-state glucose-infusion rates required to maintain euglycemia were determined. Glucose disposal at maximal insulin levels was 11.9 +/- 0.4 mg/kg/min in normals, with a 29% decrease in obese and a 42% decrease in Cushing's syndrome patients. Half maximally effective insulin concentrations were increased in both abnormal groups compared to normals. Maximal insulin clearance rates were 1460 +/- 200 ml/min/m2 in normals, not significantly changed in obese and 40% decreased in Cushing's syndrome patients. These results indicate that the insulin resistance in Cushing's syndrome is distinct from that occurring in obesity and is characterized by both decreased insulin responsiveness and decreased insulin clearance. These impairments could be caused by a common defect which may be at or distal to the glucose transport level.

Biological Transport↗

Increased insulin responsiveness and insulin clearance in thyrotoxicosis.

The euglycemic insulin clamp technique was used to evaluate in vivo insulin action in thyrotoxicosis (TTX). Insulin was infused at 0.5, 3 and 10 mu/kg per min, and the steady-state glucose infusion rate was determined in five TTX patients with fasting hyperinsulinemia and five healthy subjects. TTX is accompanied by a significant increase in insulin responsiveness, clearance and basal insulin delivery rate. Therefore, insulin resistance in TTX does not reside at the postreceptor peripheral tissue level, but may be the consequence of increased hepatic glucose production.

Blood Glucose↗

Immune derangements in asymptomatic male homosexuals in Israel: a pre-AIDS condition?

We have described several immune derangements found in a clinically asymptomatic group of 117 male homosexuals (MHS) in Israel. These consisted of a marked decrease in TH and TS cells, decreased NK and allogeneic response, and increased levels of acid labile alpha-interferon and circulating immune complexes (CIC). Most of these alterations were found in approximately 40% of the subjects, with no simple correlation between them. Since Israel is a low incidence area for AIDS and related syndromes, it is suggested that this situation reflects a common situation among asymptomatic MHS in general, although the reasons for these impairments are not clear. This situation may therefore explain susceptibility of the male homosexual for developing AIDS, given the appropriate circumstances, environment, and genetic background.

Acquired Immunodeficiency Syndrome↗

Cellular immunity in children with coeliac disease.

The experimental evidence implicating defective cell-mediated immunity in coeliac disease, a condition where symptomatology is believed to be due to immunological reaction to wheat gluten, is often inconsistent and sometimes controversial. Studies of certain parameters of cellular immunity in four groups of pediatric patients were performed: coeliac patients on normal diet; coeliac patients consuming gluten-free diet; children with cow's milk sensitivity. In all these assays no significant differences were found between treated or untreated coeliac children, infants with milk allergy or the gastro-intestinal control groups. On the basis of this study we could find no evidence of impairment of cell-mediated immunity in coeliac children. This conclusion is compatible with the hypothesis that intestinal damage may be due to a subpopulation of lymphocytes sensitive to gluten in persons with normal immune systems. In adults where abnormalities of cell-mediated immunity have sometimes been noted, the reason could be a loss of lymphocytes from the damaged mucosa of the gastrointestinal tract following prolonged antigenic stimulation. This indicated the need for strict adherence to a gluten-free-diet.

Adolescent↗

Effect of gluten-free diet on an immunological assay for coeliac disease.

The leucocyte migration inhibition factor (LIF) test for the presence of lymphocytes sensitised to gluten was evaluated over the past 4 years in patients with coeliac disease and correlated with the presence of gluten in the patients' diet. 149 LIF tests were done in 66 coeliac patients, 35 of whom were on a normal diet. However, 7 of 8 clinically and histologically diagnosed cases of coeliac disease who were LIF negative when first tested on a normal diet became LIF positive when placed on a gluten-free diet, so that 94% of patients with coeliac disease were LIF positive. On a prolonged gluten-free diet about 50% of LIF-positive cases became negative. The response to the LIF test seems to be related to gluten intake, with higher LIF values when the patient is taking gluten, and lower values when gluten is eliminated from the diet.

Celiac Disease↗

Isolation and haracterization nonconverting mutants of bacteriophage epsilon 34.

epsilon(34) Is a converting bacteriophage which brings about a glucosylation of the O antigen in the E group salmonella, thus producing antigen 34. Uridine diphosphate glucose is the precursor of antigen 34 and a glucosyl-lipid is an essential intermediate in this process. Mutants of epsilon(34) which cannot produce antigen 34 have been isolated. Cells lysogenic for these mutants are of two types. Type 1 mutant lysogens cannot form the glucosyl-lipid intermediate; those of type 2 can form glucosyl-lipid but are unable to transfer glucose from the lipid to the O antigen.

Adsorption↗

Differential gene expression between visceral and subcutaneous fat depots.

Abdominal obesity has been linked to the development of insulin resistance and Type 2 diabetes mellitus (DM2). By surgical removal of visceral fat (VF) in a variety of rodent models, we prevented insulin resistance and glucose intolerance, establishing a cause-effect relationship between VF and the metabolic syndrome. To characterize the biological differences between visceral and peripheral fat depots, we obtained perirenal visceral (VF) and subcutaneous (SC) fat from 5 young rats. We extracted mRNA from the fat tissue and performed gene array hybridization using Affymetrix technology with a platform containing 9 000 genes. Out of the 1 660 genes that were expressed in fat tissue, 297 (17.9 %) genes show a two-fold or higher difference in their expression between the two tissues. We present the 20 genes whose expression is higher in VF fat (by 3 - 7 fold) and the 20 genes whose expression is higher in SC fat (by 3 - 150 fold), many of which are predominantly involved in glucose homeostasis, insulin action, and lipid metabolism. We confirmed the findings of gene array expression and quantified the changes in expression in VF of genes involved in insulin resistance (PPARgamma leptin) and its syndrome (angiotensinogen and plasminogen activating inhibitor-1, PAI-1) by real-time PCR (qRT-PCR) technology. Finally, we demonstrated increased expression of resistin in VF by around 12-fold and adiponectin by around 4-fold, peptides that were not part of the gene expression platform. These results indicate that visceral fat and subcutaneous fat are biologically distinct.

Adipocytes↗

Repair of internal carotid aneurysm under local anaesthesia. Case report.

Aneurysms of the extracranial carotid arteries are unusual events but cause death or a cerebrovascular accident in the majority of cases (50-70%). This report describes a true internal carotid artery aneurysm that developed within six weeks. The aneurysm was resected and the artery repaired by the use of a graft from the internal jugular vein. Carotid cross-clamping time was 93 minutes. The operation was performed under local anaesthesia, with continuous clinical monitoring of the ipsilateral cerebral hemisphere function.

Anastomosis, Surgical↗

Ultrasound screening for abdominal aortic aneurysms in patients with atherosclerotic peripheral vascular disease.

The rapidly rising incidence of abdominal aortic aneurysm (AAA) and the grave prognosis in cases of rupture call for early detection and operative intervention. However, there is as yet no consensus on which groups in the population should be selected for screening. Some Authors have suggested the screening of populations at risk by virtue of their age, sex and/or the presence of arterial hypertension, and report the incidence of AAA in these populations as 5.3%, 3.4% and 0.25%, respectively. In this study we screened a group of patients with atherosclerotic peripheral vascular disease. Within this group the incidence of aneurysms was found to be 5.9%, which is at least twice the estimated incidence in the general population. Three of the six patients discovered, successfully underwent surgery. We conclude that screening of this specific population group is considerably more cost-effective than universal screening.

Aged↗