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Biomedical subjects

D Cohen

Publications and source records attributed to D Cohen.

At least 829 records · Page 46Linked to original sources
PubMedDate not supplied

Immunity to measles in young adults in Israel.

The likelihood of an epidemic of measles in 1990-92 in Israel prompted us to study the immune status against measles in a random sample of 454 recruits aged 18-19 years in order to obtain data that might be used in determining vaccination policy. This cohort had received one dose of measles vaccine at 12 months of age. The measles immunity status was studied by determination of antibody values that were measured by means of an enzyme-linked immunosorbent (ELISA) IgG antibody test. Of the recruits, 84.6% were found to have positive sera for anti-measles IgG antibodies, while 13.7% had negative sera. Eight (1.7%) subjects had borderline results. The results of this study indicate the need to administer a second dose of measles vaccine at an older age in addition to the MMR (measles, mumps, rubella) vaccine that is now given in Israel at 12 months of age. This step will help achieve the World Health Organization's target of complete eradication of measles.

Adult↗
PubMedDate not supplied

Prevalence of anti-hepatitis A antibodies, hepatitis B viral markers, and anti-hepatitis C antibodies among immigrants from the former USSR who arrived in Israel during 1990-1991.

The goal of this study was to assess the susceptibility of the sub-population of over 500,000 immigrants from the former USSR who came to Israel during 1989-94 to HAV infection, and to provide military physicians with estimates of the prevalence of HBV and HCV carriage in this sub-population. 987 males aged 17-49 and 195 females aged 17-19, reporting to military recruitment offices between December 1991 and March 1992 were tested. Anti-HAV, anti-HBV antibodies and hepatitis B surface antigen (HBsAg) were detected by using standard enzyme immunoassay (EIA) tests, and anti-HCV antibodies by a second-generation EIA and confirmed by a third-generation INNO-LIA test. It was found that in the 17-19-year age-group the prevalence of anti-HAV antibodies was 37%, anti-HBV was 12.8%, HBsAg was 3.0% and anti-HCV 1.3%. All markers were higher among males. The prevalence of anti-HAV and anti-HBs antibodies increased with age among males. That of HBsAg and anti-HCV antibodies increased with age overall. In the multiple logistic regression analysis, HAV and HBV seropositivity were significantly associated with the mother's education and republic of origin. It was concluded that the prevalence of anti-HAV antibodies is similar to that among the local population, which should not be considered at a higher risk of infection during military service. On the other hand, the higher prevalence of HBsAg and anti-HCV antibodies in this sub-population should heighten the awareness of the possibility of chronic liver pathology.

Adolescent↗
PubMedDate not supplied

Immune status against diphtheria among immigrants from the former USSR who arrived in Israel during 1990-1991.

Large outbreaks of diphtheria occurred recently in the former USSR. Between 1989 and 1994, a total of about 600,000 Soviet immigrants arrived in Israel. The immune status against diphtheria in a sample of 992 men aged 17-49 and 195 women aged 17-19, who arrived in Israel during 1990-91, was studied in order to evaluate the need for vaccination. Participants completed a self-administered questionnaire and diphtheria antitoxin antibody levels were measured by means of ELISA. At age 17-19, the prevalence of antitoxin antibody levels below the protective level of 0.01 IU/ml was 4.8% in the men and 2.1% in the women. Among the men, the percentage lacking protection declined from 4.8% at age 17-19 years to 1.6% at age 20-24, and increased to 18.2% at age 35-49. In the oldest group, the prevalence of those lacking protection was considerably higher than for the general Israeli population. In the multivariate analysis, age, mother's education and republic of origin were significantly associated with the absence of protection. Immigrants from the former USSR appear to be more susceptible to diphtheria, thus increasing the possibility of clinical disease, and it is recommended that they receive booster doses of diphtheria toxoid.

Adolescent↗
PubMedDate not supplied

Decline in CD28+ T cells in centenarians and in long-term T cell cultures: a possible cause for both in vivo and in vitro immunosenescence.

The dramatic decline in immune function with age, especially in T cell proliferative activity, has been documented extensively in experimental animal models and in clinical studies of the elderly. A similar proliferative decline is also seen in long-term T lymphocyte cultures used to study in vitro cellular senescence. We have compared the peripheral blood T lymphocytes of centenarians and younger controls for the cell surface expression of CD28, a costimulatory molecule that is required for optimal activation and proliferation following engagement of the T cell receptor. Our analysis shows a significant decrease (p < 0.001) in the percentage of T cells expressing CD28 in the elderly cohort, with values ranging from 44% to 90%, as compared to the mean control value of 91%. The decline in the percentage of CD28+ T cells correlates with a reduction in the CD4/CD8 ratio (r2 = 0.695, p < 0.0001). Concommitantly, experiments using an in vitro T cell culture system showed a progressive loss of CD28 expression with culture "age." The concordance of proliferative decline and loss of CD28 in the centenarians and in the in vitro cultures suggest that a Hayflick phenomenon may operate in vivo leading to immunosenescence.

Adult↗
PubMedDate not supplied

CT findings in visceral leishmaniasis mimicking lymphoma.

A case of visceral leishmaniasis (Kala-Azar) is presented which clinically and on CT examination mimicked lymphoma. The value of the recognition of the previously unreported CT findings of visceral leishmaniasis is discussed.

Adult↗
PubMedDate not supplied

Psychosocial correlates of pain attributions in women with dyspareunia.

The relationship between patients' causal attributions for pain and biopsychosocial measures was investigated in a sample of 100 women with dyspareunia. Independently of findings from the gynecological examinations, causal attributions were related to adjustment. More specifically, the women who made psychosocial attributions reported higher pain scores, higher levels of psychological distress, lower levels of marital adjustment, more problems with sexual function, and more frequent reports of sexual assault. The relationship between psychosocial causal attributions for pain and psychosocial distress may be clinically useful in the multidisciplinary treatment of this and other pain disorders, regardless of actual physical pathology.

Adaptation, Psychological↗
PubMedDate not supplied

Word identification in adults with mild mental retardation: does IQ influence reading achievement?

OBJECTIVE: To assess the relationship between word identification and intelligence in adults with mild mental retardation (IQ < 80). METHOD: A standardized evaluation was administered to 67 adults with mild mental retardation. The evaluation included a psychiatric interview, the WAIS-R, and a 2-h interview with a speech therapist and reading tests. RESULTS: Causes of mental retardation were diverse in the sample, and IQ scores ranged from 43 to 79 (mean score = 64). All subjects exhibited reading impairment, including 69% with severe impairment. No subject with an IQ score under 65 was able to perform adequately in the word identification tasks. Word identification was correlated with total and verbal IQ, but not with performance IQ. CONCLUSION: Our results suggest that, in contrast to subjects with normal intelligence, IQ score is correlated with reading in subjects with mild mental retardation. Finally, remediation should be preferentially implemented for subjects with IQ score greater than 65.

Achievement↗
PubMedDate not supplied

Reasons for intracranial hypertension and hemodynamic instability during acute elevations of intra-abdominal pressure: observations in a large animal model.

In previous studies we reported that an acute elevation in intra-abdominal pressure (IAP) is responsible for the elevation in intracranial pressure (ICP) and mean blood pressure (MBP). Thus far, the reasons for the increased ICP during an acute elevation in IAP and the combined effects of increased IAP and ICP on hemodynamics have not been reported. Five large animals (swine) were studied. Each animal served as its own control. A subarachnoid screw was placed for ICP monitoring. The jugular vein, femoral vein, and femoral artery were cannulated. ICP, MBP, central venous pressure above (CVPA) and below (CVPB) the diaphragm, and PaC02 were monitored after a pneumoperitoneum with C02 was established at 5, 15, and 30 mm Hg of IAP. Cavography was performed to evaluate the morphology of the inferior vena cava at different increments of IAP. Measurements were obtained in reverse Trendelenburg (group 1), supine (group 2), and Trendelenburg (group 3) positions. Multiple regression analysis was used to examine the effects of IAP and positioning in separate models with different blood pressures as dependent variables. Increased IAP significantly increased CVPA, CVPB, ICP, and MBP. There were no changes in cerebral perfusion pressure. The change in position (from group 1 to group 3) significantly increased CVPA and decreased the CVPB. Cavograms performed on animals in the supine position with increased IAP showed a narrowing of the IVC at the level of the diaphragm. Increases in IAP will increase ICP and MBP without altering the cerebral perfusion pressure. A mechanical effect mediated by compression of the inferior vena cava at the level of the diaphragm with increased central venous pressure and decreased drainage from the lumbar plexus and central nervous system is responsible for this effect.

Abdomen↗
PubMedDate not supplied

The HIV 'A' (sor) gene product is essential for virus infectivity.

The genome of the human immunodeficiency virus (HIV) contains several open reading frames (ORFs) not present in other viruses. The 'A' gene, also known as Q2 P'3, ORF-1(4) or sor5, partially overlaps the pol gene; its protein product has a relative molecular mass of 23,000 (Mr 23K) and is present in productively infected cells. The function of this protein is unclear; mutant viruses deleted in 'A' replicate in and kill CD4+ lymphocyte lines, but the high degree of conservation of the deduced amino-acid sequence in nine different HIV isolates (80%) and the presence of analogous genes in HIV-2 and other lentiviruses suggest that the gene function is an important one. Here we describe a mutant virus deficient in the 'A' gene which produces virion particles normally; however, the particles are approximately 1,000 times less infective than wild type. Transcomplementation experiments partially restore infectivity. The mutant virus spreads efficiently when virus-producing cells are co-cultivated with CD4+ lymphocytes, however, indicating that HIV can spread from cell to cell in a mechanism that does not require the 'A' gene product and probably does not require the production of infective virus particles.

Amino Acid Sequence↗
PubMedDate not supplied

Memory for a geometrical configuration in the cognitively impaired elderly.

The objective of this study was to analyze the mnemonic reconstruction of a complex spatial configuration in a group of 10 men and women, 70-88 years, with a diagnosis of organic brain syndrome and 10 controls matched for age, sex and educational background. A Piagetian model of a geometrical configuration with contingent and non-contingent properties was used to establish a heirarchical order of memorial organization for spatial structures. Subjects were evaluated one hour and one week after learning in reconstruction tasks. Although individuals with dementia performed more poorly than the age-matched controls, the hierarchy of chosen characteristics reflected a schematic progression in the organization of spatial memory in both groups.

Aged↗
PubMedDate not supplied

Four decades of shigellosis in Israel: epidemiology of a growing public health problem.

Despite the improved standard of living in Israel, shigellosis remains a common disease. Examination of trends in the incidence of shigellosis in Israel between 1951 and 1987 showed a period of declining rates followed by an increase in the reported incidence beginning around 1969. This increase was mainly due to Shigella sonnei; rates of infection with Shigella flexneri remained relatively constant. Trends showed marked differences between age groups and between ethnic groups. In comparison, the rates in the United States--much lower than those in Israel--began to decline in the early 1950s and have remained low. The incidence in Israel is now about 20 times higher than that in the United States. Thus shigellosis remains a major and growing public health problem in Israel, a country that has enjoyed a dramatic improvement in basic sanitary services and infrastructure over the past few decades. This disturbing finding lends urgency to efforts to control the disease.

Adolescent↗
PubMedDate not supplied

Surface analysis of bileaflet prosthetic heart valve leaflet leading edge.

In 1991 and 1992, two patients presented with persistent clinical hemolysis after mitral valve replacement with bileaflet valves, in the absence of paravalvular leaks. When each valve was replaced, the hemolysis disappeared. The first valve was not examined in the laboratory owing to its loss, but it looked normal. The second valve was tested and found to have normal hemodynamics and a normal appearance by light microscopy (LM) and scanning electron microscopy (SEM), but fringe pattern interferometry (FPI) showed its leading leaflet edges to be flatter and rougher than another St. Jude Medical valves (SJMV). This led the authors to collect 17 bileaflet valves (14 SJMV and 3 Carbomedics) for examination of their surface characteristics to see if there was any correlation with hemolysis. All valves were examined by LM, SEM, and FPI. However, only FPI indicated the presence of notable differences in surface roughness and convexity of the leading leaflet edges. Further, convexity of an edge tended to vary inversely with its roughness, and the flat inlet surfaces of most leaflets were consistently less rough than the adjacent edge. The authors' hemolytic valve had one of the flattest and roughest edges of the series. Roughness of the leading edge may contribute to hemolysis by presenting an abrasive surface to the antegrade flow of blood, and by forming the sides of the gap between the leaflets, through which blood is squeezed during closed regurgitation, generating substantial shear forces and causing hemolysis. FPI is a noncontact, sensitive modality, useful in screening pyrolytic carbon surfaces but, unlike other current methods, it is reproducible, does not require modification of the surface, and causes no alteration of the surface texture.

Anemia, Hemolytic↗
PubMedDate not supplied

Erythropoietin (EPO) requirements remain high in EPO resistant patients after iron repletion.

Iron deficiency is an important factor for high erythropoietin (EPO) requirements. Some studies have shown a decrease in recombinant human erythropoietin (rHuEPO) dosage with correction of iron deficiency. This is a 2 year prospective study of 58 chronic hemodialysis (HD) patients in whom iron deficiency was corrected with intravenous iron therapy. Patients were stratified into two groups: Group 1 with 25 patients (EPO < 70 U/kg per HD), and Group 2 with 33 patients (EPO > 70 U/kg per HD). For Groups 1 and 2, respectively, differences in mean age (56.5 vs 64.1 years), rHuEPO dose (30.1 vs 148.7 U/kg per HD), and hematocrit concentration (36.5% vs 32.7%) were statistically significant (p < 0.05). Although iron saturation was 45% compared with 41.3% for Groups 1 and 2, respectively, serum parathyroid hormone, aluminum, and urea reduction ratio were similar for both. These data suggest that some patients continue to require a high rHuEPO dose in spite of adequate iron repletion. Further investigation into factors causing EPO resistance is important to decrease rHuEPO requirements and improve cost effectiveness.

Dextrans↗