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Biomedical subjects

O Cohen

Publications and source records attributed to O Cohen.

At least 145 records · Page 8Linked to original sources
PubMed1983

Analysis of HLA class I genes with restriction endonuclease fragments: implications for polymorphism of the human major histocompatibility complex.

Cellular DNA from HLA-typed individuals was digested with the restriction endonucleases HindIII, EcoRV, and EcoRI. The separated restriction endonuclease fragments were hybridized with a HLA class I cDNA probe by using the Southern transfer technique. Digestion of cellular DNA with HindIII generated 22 restriction endonuclease fragments, 11 of which showed polymorphism for presence or absence in a population sample. With EcoRV, 13 fragments were identified; 6 showed polymorphism. EcoRI generated 11 fragments, of which 1 was polymorphic. Of these 18 polymorphic fragments generated by the three restriction endonucleases, each of 5 was found to be positively associated with one allele of the HLA-A or -B allelic series (HLA-Aw24, -B8, -B15, -Bw35, and -B40). One fragment was positively associated with two HLA-A series alleles (HLA-A1 and -A11). Another fragment was positively associated with five HLA-B series alleles (HLA-B5, -B7, -B14, -Bw16, and -Bw35) and one fragment was positively associated with alleles at two loci (HLA-B14 and -Cw5). The serologically defined allele HLA-Aw24 was associated with two polymorphic fragments, one association showing a positive correlation and the other a negative correlation. Each informative family studied thus far has shown segregation of the restriction fragment with the associated serologically defined allele. The fragments associated with serologically defined alleles occurred in the population sample studied at low or moderate frequencies. The remaining polymorphic fragments occur at high frequency, suggesting that class I genes not serologically detected show less polymorphism than serologically defined class I genes.

Alleles↗
PubMed1983

Histocompatibility antigens, mixed lymphocyte reactivity and severe preeclampsia in Israel.

In the present study we have attempted to ascertain the possible existence of an association between antigens of the major histocompatibility complex (MHC) and development of severe preeclampsia (PE). HLA-A, B, C, DR antigens as well as reactivity in one-way mixed lymphocyte culture (MLC) were studied in 40 couples with severe PE, and subsequently compared to 30 normal fertile control couples. No significant differences in the frequencies of HLA antigens were detected between PE and control couples. The frequency of shared HLA-A, B and DR antigens among members of the couples was similar in both groups. The one-way MLC showed normal reactivity of both parental pairs in all combinations tested. Consequent to our data we are unable to support the suggestion that the MHC affects the susceptibility to develop severe PE.

Female↗
PubMed1982

Abnofmalities in brain myelin or rabbits with experimental autoimmune multiple sclerosis-like disease induced by immunization to gangliosides.

An experimental autoimmune multiple sclerosis-like disease (EAMSD) was induced in rabbits by immunizing them with bovine brain gangliosides. Forebrain myelin was isolated and fractionated on a discontinuous sucrose gradient into light myelin (LM, buoyant density less than or equal to 0.625 M), and heavy myelin (HM, buoyant density greater than 0.625 M). No abnormalities in either protein or lipid composition of EAMSD myelin fractions were observed. However, the EAMSD tissue yielded 31% less light and 39% more heavy myelin compared to the control brains. Thus, the HL/LM ratio was two-fold greater in experimental than in control myelin. This pathological pattern is similar to that which has been observed in myelin obtained from the brains of multiple sclerosis patients and from the optic nerves of rabbits with experimentally-induced demyelination.

Animals↗
PubMed1981

Genetics of insulin dependent diabetes mellitus in Israel: population and family study.

The association between insulin dependent diabetes mellitus (IDDM) and the HLA system was studied in two groups of Jewish patients: 50 Ashkenazim and 42 non-Ashkenazim. The pattern of association of HLA-A and B locus antigens was somewhat different from that observed in European Caucasian patients. HLA-B8 had a higher frequency; B15 and Cw3 were rare in the population studied and were less frequent in IDDM patients than in controls. On the other hand, the frequency of A26, B18, and Bw38 was increased in Ashkenazi patients, but not in non-Ashkenazim, who in turn showed an increase for Bw51. Although the association between IDDM and HLA-A and B locus antigens shows a marked variability in different populations, the association with HLA-DR3 and DR4 is constant feature. There was a typical excess of DR3/DR4 heterozygotes in both patient groups. This heterozygote type carries the highest relative risk, followed by DR4/DR4 homozygotes. These data can well be interpreted by a model of two different HLA-linked susceptibility genes, one associated with DR3 and the other one with DR4, that interact so that different genotypes are associated with different levels of penetrance. This model received further support from studies in 15 multiple case families where there is an excess of affected sib pairs sharing two DR antigens.

Adolescent↗
PubMed1980

Horner's syndrome: a complication of internal jugular vein cannulation.

Percutaneous internal jugular vein cannulation has become an accepted method for placement of central venous catheters. A variety of complications connected with this procedure have been noted, but direct injury to the sympathetic trunk causing Horner's syndrome is extremely rare. A description of repeated attempts of percutaneous cannulation of the right internal jugular vein which led to the occurrence of Horner's syndrome is given.

Adult↗
PubMed1979

Acute appendicitis in a premature baby.

Acute appendicitis with perforation in a premature baby, weighing 1 050 g, is described. Initially the infant did well after surgery, but succumbed to sepsis, as a result of hyperalimentation, eleven days later. This is the smallest infant suffering from appendicitis reported in the English literature.

Acute Disease↗
PubMed1977

Traumatic hemolysis after aortofemoral bypass. A study of 25 cases.

The prevalance of traumatic intravascular hemolysis was estimated in 25 patients following aortofemoral bypass. Stigmata of mild red cell fragmentation were noted in approximately one third of the patients, but in only one of them was hemolysis of sufficient severity to be of clinical significance. The case history and laboratory findings in this patient are described in detail. This study indicates that traumatic hemolysis should be considered as a possible cause of anemia developing after aortofemoral bypass.

Aged↗
PubMedDate not supplied

Computer-assisted image analysis of small cell lymphoma of the thyroid gland. Comparison of nuclear parameters of small lymphocytes in lymphomas and Hashimoto's thyroiditis.

The nuclear parameters of the small lymphocytes in nine cases of small cell lymphomas of the thyroid gland and 17 cases of Hashimoto's thyroiditis were assessed by computer-assisted image analysis. The nuclear area, maximal, minimal and averaged Ferret diameters, perimeter, regularity factor and elongation factor were gauged. Statistically, the nuclear area was ascertained to be the optimum descriptor discriminating between small neoplastic and reactive lymphocytes. Application of a novel variable, combining a nuclear area cut-off value of 14 microm2 with a nuclear averaged Ferret diameter cut-off value of 4.5 micron, allows for the distinction - with a high degree of sensitivity and specificity - between small neoplastic lymphocytes in thyroidal lymphomas and the reactive lymphocytes in Hashimoto's thyroiditis.

Adult↗
PubMedDate not supplied

Significance of elevated levels of serum creatine phosphokinase in febrile diseases: a prospective study.

The incidence and significance of elevated serum levels of creatine phosphokinase (CPK) in febrile diseases were studied prospectively in all patients admitted with fever to a department of medicine during 1 year. High serum CPK levels were detected in 70 (28%) of 247 febrile patients but in only six (6%) of 105 afebrile control patients (P = .0001). Elevated CPK levels were not related to any specific diagnosis. Logistic regression analysis identified five factors that correlated both significantly and independently with elevation of CPK values: increased blood urea nitrogen level, low serum phosphate level, a stuporous or comatose state, tremor, and muscle tenderness. Myoglobinuria, detected in 14 patients, was predictive of a fatal outcome, but a high CPK level by itself was not an independent correlate of mortality. In summary, CPK elevation is not uncommon in febrile diseases, but because it does not reflect a specific etiology it does not necessarily indicate that an extensive diagnostic work-up is required.

Adult↗
PubMedDate not supplied

Transplacental effect of a 15% olive-oil diet on functional activity of immune components in the spleen and colon tumors of rat offspring.

We studied whether feeding pregnant female rats a 15% olive-oil diet affects the activity of lymph cells in the spleen and tumors in offspring with chemically-induced colon tumors. Rat mothers were fed either a 7% corn-oil or a 15% olive-oil diet. Five-week-old male offspring were divided into 3 groups. A control group was fed the 7% corn-oil diet similar to their mothers. The experimental group I was fed the 7% corn-oil diet whereas their mothers were fed the 15% olive-oil diet. The experimental group II was fed the same 15% olive-oil diet as their mothers. Experimental rats were injected weekly for 8 weeks with the carcinogen, 1,2-dimethylhydrazine (DMH), 20 mg/kg b.w. Results of experiments were studied 6 months later. The area of zones in the spleen responsible for producing B and T lymphocytes were measured and the number of cells counted. The activity of lymphoid elements of the spleen and of tumors were studied using immunohistochemical methods for evaluating the synthesis of CD8(+) lymphocytes and proliferative activity of lymphocytes in spleens and tumors. Feeding pregnant or lactating mothers with the 15% olive-oil diet had no marked tumor-protective effect on chemically-induced colon cancer in offspring. Diet-dependent changes were found at the cellular level. In the spleen of control offspring, the presence of a tumor was accompanied by an increase in the number of Ki-67(+) cells and CD8(+) lymphocytes in the red pulp. In experimental group I, DMH significantly increased the total cell number and the number of CD8(+) lymphocytes in the red pulp of the spleen in both tumor-bearing and tumor-free rats. In experimental group II, the total number of lymph cells and the number of CD8(+) lymphocytes increased compared to offspring fed a control diet. Tumor formation activated the proliferative activity of lymph elements. The total number of cells in infiltrates of the colon mucosa decreased in tumor-bearing rats compared to tumor-free counterparts, and this was seen in all three dietary groups of rats. In tumors from offspring of experimental group II, only the number of CD8(+) lymphocytes increased compared to those in offspring of experimental group I. The findings indicate that feeding mothers the 15% olive-oil diet had a cancer-inhibiting role in offspring, predominantly changes at the cellular level.

1,2-Dimethylhydrazine↗