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Biomedical subjects

M Levin

Publications and source records attributed to M Levin.

At least 37 records · Page 2Linked to original sources
PubMed1991

Deficiency of prostacyclin production in meningococcal shock.

A deficiency of prostacyclin (PGI2) production by the vascular endothelium might underline the severe vasoconstriction and intravascular thrombosis that characterise meningococcal shock. The effect on PGI2 synthesis by human umbilical vein endothelial cells (HUVEC) in culture was examined in sera from children with meningococcal shock, healthy adults, and children with other febrile illnesses. In comparison with adult controls, PGI2 synthesis was reduced when HUVEC were incubated with the sera from 10 of 13 patients with meningococcal shock. A similar defect was observed with only four of 20 sera from children with other febrile illnesses. The effect of sera from patients with meningococcal shock on HUVEC was reversible with normal serum, and seems to be due to the absence of a factor necessary for PGI2 production rather than an inhibitor. These findings suggest that a deficiency of PGI2 may have a role in the pathogenesis of meningococcal shock and that exogenous PGI2 may be of therapeutic benefit.

Adult↗
PubMed1991

Clinical aspects of 100 patients with Kawasaki disease.

We report 101 episodes of Kawasaki disease in 100 patients seen over a 12 year period. A total of 35 patients had cardiac involvement ranging from pericardial effusion to coronary artery aneurysms with ischaemic complications, which resulted in death in one patient. Laboratory investigations showed leucocytosis, thrombocytosis, and a raised erythrocyte sedimentation rate to be common features and the first two variables were significantly associated with cardiac involvement. Treatment regimens changed over the study period. Aspirin was used in most patients often in conjunction with dipyridamole and from 1986 intravenous immunoglobulin was given routinely to those patients seen early in the illness. Additional therapeutic measures in individual patients included prostacyclin, heparin, streptokinase, and plasma exchange/exchange transfusion. Attention is drawn to the uncertainity of the long term cardiovascular consequences in the light of adults reported with premature atherosclerotic lesions of similar appearance to those seen in Kawasaki disease.

Aspirin↗
PubMed1991

Use of vincristine in refractory thrombotic thrombocytopenic purpura.

We describe 3 patients with thrombotic thrombocytopenic purpura (TTP) treated with vincristine. In 2 of them, multimodality treatment with plasmapheresis, acetylsalicylic acid, dipyridamole, corticosteroids, and plasma infusions did not achieve lasting remission, subsequent to which the administration of vincristine was followed by prompt and durable remission. In the third patient, 1 mg of intravenous vincristine as initial therapy in conjunction with multimodality treatment resulted in the prompt resolution of the disease. Our experience suggests that vincristine is effective in the treatment of TTP and can be used as initial treatment in combination with other modalities.

Adolescent↗
PubMed1991

Gender differences in the utilization of emergency department services.

Some of the suggested explanations of the well documented gender morbidity differences imply that these are not 'real' but the result of women's tendency to perceive and report more symptoms, to magnify symptom severity, and to seek help. To contribute to this debate, gender differences in utilization of a general hospital emergency department (ED), often used as a primary care service and for mild conditions, were studied. Data were collected from the general ED admissions registry for 6815 patients. In our data strikingly more men than women visited the ED during the period studied; generally, the same proportion of men and women were self-referred patients; and similar rates of both sexes were hospitalized regardless of type of referral. Thus, these findings suggest that, at least among ED patients, there is no gender differential in symptoms perception, evaluation, or presentation. Indications for these were somewhat found among young patients (aged 17-24) only. Alternatively, the findings with regard to this age group could reflect professional gender stereotyping at the primary care level.

Adolescent↗
PubMed1991

Sonography of the eye.

Real-time sonography of the eye is a technique that is rapidly performed and readily available in most sonography departments. It is less expensive than CT and MR imaging and, if necessary, may be performed at the patient's bedside. This essay demonstrates a few of the large number of clinical entities that may be successfully examined with this technique.

Eye↗
PubMed1990

Emergency department utilization: a comparative analysis of older-adults, old and old-old patients.

A comparative analysis of Emergency Department (ED) utilization by 2936 older-adults, old, and old-old patients was conducted in the only hospital available for residents of a vast geographical region. All patients (45+) who arrived at the ED during the first week of every even month from September 1986 to August 1987 were selected for the study. No significant differences were found among the three groups with regard to sociodemographic characteristics other than age. Data showed that the old-old use the ED approximately twice as much as the old and the older-adults; they also use the ED more often than the two other groups during the winter season. These two findings indicate the utility of viewing the old-old not only as a part of the elderly population, but also as a unique risk group. Hospitalization rates present a different pattern: they double in each age group moving from the youngest to the oldest. Complaints of an internal medicine nature are more often presented by the two groups of the elderly in comparison to the older-adults, and are followed by more frequent hospitalizations in internal medicine wards. Such findings have practical implications, and should be taken into consideration by policymakers.

Age Factors↗
PubMed1990

Emergency department utilization by two subcultures in the same geographical region.

An exploratory study of emergency department (ED) utilization, comparing Israeli adult Jews and Bedouin Arabs was conducted. The data interpretation derived from the premise that health services utilization reflects not only morbidity patterns but characteristics of both subcultures and the structure of health services. The Bedouins in the study are a Moslem traditional society going through a rapid process of urbanization and modernization, with a relative deficiency in primary health services. Data were collected from the general ED admissions registry. Patients (17+) who arrived at the ED during the first week of every even month of one calendar year were selected for this study (6815 Jews and 583 Bedouins). The findings indicate that, in general Bedouins use the ED significantly less than Jews. They adjust to the structure of the ED services and use them, more than Jews, as a primary service. Yet, the hospitalization rates of the two populations are similar. In both subcultures the pattern of gender differences changes after the age of 45. The change, however, is in the opposite direction. Differences in ED usage among Bedouin age-sex groups are discussed in terms of changes in social status during a period of socio-cultural transition.

Adult↗
PubMed1990

Absence of effect of dipyridamole on renal and platelet function in diabetes mellitus.

We evaluated the effect of dipyridamole (5 mg/kg/day) for 12 months on renal and platelet function in 53 children with insulin dependent diabetes mellitus (IDDM) in a prospective double blind placebo controlled trial. Urine albumin excretion (expressed as the geometric mean albumin to creatinine concentration ratio (UA/UC) was measured every three months throughout the study. At 12 months, the geometric mean UA/UC was no different in diabetic children receiving dipyridamole, 0.60 mg/mmol, when compared with those receiving placebo, 0.87 mg/mmol. Glomerular filtration rate, urinary excretion of retinol binding protein, and N-acetyl-beta-D-glucosaminidase (NAG), blood pressure, and spontaneous platelet aggregation in response to stirring whole blood did not differ between the two groups at 12 months. Subgroup analysis to include only those children with high UA/UC before entry into the study also failed to show an effect of the drug on UA/UC. Eleven children had either persistently high UA/UC (n = 8: four on dipyridamole, four on placebo) or progression to high UA/UC (n = 3: two on dipyridamole, one on placebo). These children had significantly higher urinary excretion of retinol binding protein and NAG, bigger kidneys, and higher diastolic blood pressure both before and after treatment than the remaining 42 children, whereas there was no difference in spontaneous platelet aggregation between the two groups. These observations on the associations between UA/UC and other parameters of renal function suggest that measurement of 'tubular' proteins and diastolic blood pressure as well as UA/UC may contribute to the identification of those at risk of developing nephropathy.

Adolescent↗
PubMed1990

Assessment of platelet antibody by flow cytometric and ELISA techniques: a comparison study.

Two different methods for evaluating platelet antibody were used to study 12 normal subjects and 24 patients consisting primarily of intravenous drug users (IVDUs) who were positive for human immunodeficiency virus (HIV). Total platelet-associated immunoglobulin G (IgG) and immunoglobulin M (IgM) were measured by enzyme-lined immunosorbent assay on platelet lysate, and platelet surface-associated IgG and IgM were measured by semiquantitative flow cytometry. IgG and IgM values showed significant correlations between the two measurement methods. Mean platelet surface IgG and total IgG were 3.6 and 4.3 times greater, respectively, in IVDUs than in controls, and platelet IgM was also significantly higher in IVDUs than in controls as measured by both techniques. Although mean platelet immunoglobulin levels were higher in the IVDUs with thrombocytopenia than in IVDUs with normal platelet counts, these differences did not achieve significance. These data show that platelet IgG and IgM levels are increased in IVDU-associated HIV infection and suggest that these increases are not confined to patients manifesting thrombocytopenia. The herein described platelet surface antibody and total platelet antibody measurements appear to be equally useful in studying this patient population. Specific details for generating platelet-associated immunofluorescence units are discussed.

Adult↗
PubMed1989

Diseases that mimic herpes simplex encephalitis. Diagnosis, presentation, and outcome. NIAD Collaborative Antiviral Study Group.

A total of 432 patients underwent brain biopsy for presumptive herpes simplex encephalitis. Three patient groups were identified. The first group, 195 patients (45%), had herpes simplex encephalitis confirmed by the isolation of herpes simplex virus from brain tissue at biopsy (193 patients) or autopsy (2 patients). The second group, 95 patients (22%), had diseases that were identified but that were not caused by herpes simplex virus. Three subgroups were recognized: (1) 38 patients (9%) with treatable disease, (2) 40 patients (9%) with nontreatable but diagnosed viral infection, and (3) 17 patients (4%) with identified diseases neither of viral etiology nor treatable. The third group, 142 patients (33%), remained without a diagnosis. Clinical presentation of patients in the second group was similar to that of those with herpes simplex encephalitis and those without a diagnosis. Patients in the subgroup with nontreatable but diagnosed viral infections had the greatest likelihood of returning to normal.

Adolescent↗
PubMed1989

Glomerular and urinary heparan sulphate in congenital nephrotic syndrome.

Studies using cationic probes have suggested that a reduction in glomerular anionic sites, composed principally of the glycosaminoglycan heparan sulphate, is responsible for the abnormal glomerular permeability in the congenital nephrotic syndrome (CNS). We therefore analysed the glycosaminoglycan content of the glomerular basement membrane (GBM) from an infant who died of CNS and from an infant who died of unrelated causes. We also measured the urinary excretion of glycosaminoglycans in children with nephrotic syndrome, both congenital and acquired, and in healthy children. Heparan sulphate constituted 59% of the glycosaminoglycan content of the GBM in the normal infant, the other principal glycosaminoglycan being chondroitin sulphate. In the GBM from the infant with CNS the heparan sulphate was greatly reduced, constituting only 3% of total glycosaminoglycans. The urinary excretion of heparan sulphate was significantly increased in CNS (expressed both in relation to creatinine and to chondroitin sulphate) compared with normal children and to those with acquired nephrotic syndrome. Diminished GBM content of heparan sulphate may be responsible for the abnormal glomerular permeability in CNS and may be a consequence of defective incorporation of heparan sulphate into the GBM with subsequent loss into the urine.

Basement Membrane↗
PubMed1989

Epidermoid splenic cyst detected on a sports physical examination.

A 14-year-old female had a large, nontender abdominal mass on a routine sports physical examination. Following evaluation by ultrasound and computed tomography scan there was an initial attempt at drainage. The mass was subsequently removed. The diagnosis was epidermoid cyst of the spleen. In this report, we discuss the epidemiology and management of a splenic cyst, a rarely encountered diagnosis in adolescents, and emphasize the life-saving potential of the abdominal examination in sports medicine.

Adolescent↗
PubMed1989

Hemorrhagic shock and encephalopathy: clinical, pathologic, and biochemical features.

To further define the clinical, pathologic, and biochemical features of hemorrhagic shock and encephalopathy syndrome, we studied 25 affected children (aged 3 months to 14 years) admitted to a single center between 1982 and 1985. A prodromal illness comprising vomiting, diarrhea, listlessness, and fever was present in 84% of the cases. Acute onset of shock, convulsions and coma, bleeding (or laboratory evidence of disseminated intravascular coagulation), elevated plasma activity of hepatic enzymes, acidosis, and impaired renal function was present in every case. Twenty patients died, and all the survivors are neurologically damaged. At postmortem examination, intravascular microthrombi coexisting with hemorrhages and petechiae were found in most organs. Centrilobular liver necrosis and cerebral edema were prominent features. No microbiologic cause for the disorder was identified, but decreased plasma levels of the protease inhibitors alpha 1-antitrypsin and alpha 2-macroglobulin, together with increased levels of circulating proteolytic enzymes, were frequently present. An overrepresentation of the uncommon variant phenotypes of alpha 1-antitrypsin was found in first-degree relatives of affected patients (four had the MZ phenotype, and one each the MS or MC phenotype, of 19 relatives studied). Abnormal accumulation of alpha 1-antitrypsin was detected immunohistochemically in the livers of six of the patients. Defective protease inhibitor production or release may be involved in the pathogenesis of the disorder.

Adolescent↗
PubMed1989

A highly cationic protein in plasma and urine of children with steroid-responsive nephrotic syndrome.

We postulated that the reduction of surface negative charge on the glomerular capillary wall, which is believed to underlie the proteinuria of steroid-responsive nephrotic syndrome (SRNS), might be due to the presence of a cationic substance which binds to and neutralizes the negative charge on cells and membranes. Using a method to detect charge neutralizing substances based on inhibition of binding of the cationic dye Alcian blue 8GX to heparin, plasma and urine from children with SRNS were found to contain a protease-sensitive charge-neutralizing factor, which was not present in plasma or urine of healthy individuals. This factor has been partially purified from SRNS plasma and urine by ion exchange chromatography on QAE Sephadex, gel filtration on Sephadex G150, and FPLC on Mono-S. This cationic protein, which binds to and neutralizes the charge on heparin, may also neutralize the negative charge on the glomerular capillary wall and may thus be involved in the pathogenesis of SRNS.

Cations↗
PubMed1989

Phenotype, cytotoxic, and helper functions of T cells from varicella zoster virus stimulated cultures of human lymphocytes.

Blood mononuclear cells (MNC) were stimulated with VZV in the form of live cell-associated virus, glutaraldehyde-fixed VZV-infected fibroblasts or an extracted VZV antigen. After 7 days of culture with live virus, IL2 receptors (IL2R) were found on CD4 and CD8 cells while cultures stimulated with fixed or extracted antigen had IL2R only on CD4 cells. Clones derived by limiting dilution from these cultures were tested for specificity by cytotoxicity to autologous VZV-superinfected B lymphoblasts, and by proliferation in the presence of antigen and antigen presenting cells. The CD8+ clones were not VZV specific in tests of cytotoxicity or proliferation. 50% of the CD4+ clones with specificity for VZV also proliferated in cultures stimulated with individual VZV glycoproteins gp I, II or III. Included amongst these were clones cytotoxic for lymphoblast targets prepared with live VZV. Most of the VZV-specific T cell clones which failed to lyse targets prepared with live VZV lysed targets prepared with heat killed VZV. Target cells were susceptible to lysis after VZV antigens were no longer demonstrable on the cell surface by immunofluorescence and monoclonal antibodies to VZV glycoproteins failed to block cytotoxicity. 5 of 8 VZV-specific CD4+ clones provided antigen-specific help to B cells for IgG antibody production. The data are consistent with the view that CD4+ T cells respond to processed VZV antigen fragments, and that these fragments include epitopes present on gp I, gp II and gp III. Additionally, some the cloned progeny of VZV specific T cells were bifunctional (expressing cytotoxicity and help for B cells) in tissue culture.

Antigens, Viral↗