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Biomedical subjects

T Cohen

Publications and source records attributed to T Cohen.

At least 109 records · Page 6Linked to original sources
PubMed1984

Admixture analysis of plasma cholesterol levels in a Jewish population sample in Jerusalem.

The frequency distribution of total plasma cholesterol levels (TC) in 17-year-old Jerusalem youngsters and their parents (n = 6,170) was examined for evidence of admixture of normal distributions. Probability plots indicated bimodality of age-adjusted TC in both sexes. Using a maximum likelihood procedure, two normal distributions fitted the age- and sex-adjusted data significantly better than 1, with 0.9% males and 1.2% females coming from a lower distribution 2-3 standard deviations below the major mode and 0.2% males and 1.1% females belonging to the higher distribution. These results suggest that single genes may determine high as well as low cholesterol levels, but are open to other interpretations, and thus require confirmation by segregation analysis. Jews originating from Europe showed the highest TC levels followed by those from Israel, Asia, and Africa. Adjustment of TC for ethnicity did not alter the above estimates. Analysis of bimodality within countries of origin showed greater separation of the distributions in Asian and Israeli origin groups than in European and North African groups, in whom there was less evidence for admixture.

Adolescent↗
PubMed1984

The distribution of ABO, MNSs, Rhesus, Kell, Duffy and Kidd blood groups of Jews originating from 20 countries.

The distribution of red blood cell antigens of 10,000 Jewish Israeli men are presented by their country of birth. The ABO, MNSs, Rh, Kell, Duffy and Kidd blood groups were examined, and their frequencies were analyzed for each of 20 countries of birth. These results can serve as control and reference data for various studies, both basic and applied, concerning Jewish communities. The data are shown in various ways: phenotype and allele frequencies are presented alphabetically by countries of birth, and the allele frequencies are also shown by lowest to highest frequencies among the communities. The data indicate that Jews from Europe and Morocco tend to have intermediate allele frequencies. At the extremes are mainly Jews from Yemen, Aden and Yugoslavia. These observations are in accordance with previous studies on genetic distances.

ABO Blood-Group System↗
PubMed1983

A muscle disorder as presenting symptom in a child with mucolipidosis IV.

Psychomotor retardation and hypotonia were found in a 1 1/2 year old girl with bilateral corneal opacities. Very high levels of enzymes of muscular origin together with abnormal electromyograms and muscle biopsy lead at the time to the diagnosis of an unspecified muscle disorder. Twelve years later mucolipidosis IV (ML IV) was diagnosed in this child. She was then very retarded, ocular and neurologic deterioration were evident and enzyme levels were still very high. Only few patients affected with ML IV have been reported and all but one were very young; therefore it is important to add observations on the progression of the disease and on unusual clinical features like muscle involvement.

Conjunctiva↗
PubMed1983

Admixture analysis of high density lipoprotein cholesterol distribution in a Jerusalem population sample.

The distribution of high density lipoprotein cholesterol values (HDL-C) in 2003 nuclear families (including both parents and one child aged 17) participating in the Jerusalem Lipid Research Clinic survey, were analyzed by a maximum-likelihood procedure for evidence of bimodality. HDL-C was age-sex adjusted by the mean-variance method to 17 year old male levels. After covariance adjustment for Quetelet's index, season, education and social class, when using untransformed data a mixture of two distributions fitted the data significantly better than one distribution in both sexes. The results indicated that 4.7% of males and 14.1% of females came from an upper distribution with mean values of 2.15-3.15 standard deviations above the major mode. We next applied the MacLean et al. (1976) method of transformation and used a maximum-likelihood method in which the skewness parameter was estimated jointly with the other parameters of the model. When the data were transformed the mixture of two distributions fitted the data significantly better than one for males only. We tested a mixture of three normal distributions and estimated that 6% of both males and females belonged to a higher distribution, while 1% came from a lower distribution. This model did not provide a significantly better fit to the data than a mixture of two distributions. Our findings imply that in the Israeli population there is evidence for an admixture in the distribution of HDL-cholesterol. Segregation analysis is necessary in order to determine whether a major gene or some environmental factors are responsible for the commingling detected.

Adolescent↗
PubMed1983

Kidney involvement in systemic lupus erythematosus and Fabry's disease.

A young female patient with both systemic lupus erythematosus (SLE) glomerulonephritis and glomerular glycolipid storage of Fabry's disease is described. The causal relationship between the two conditions is discussed and it is suggested that accumulated immunogenic galactocerebroside may have incited an autoimmune disease such as SLE.

Adolescent↗
PubMed1983

Cytotoxicity of arabinofuranosyladenine and erythro-9-(2-hydroxy-3-nonyl) adenine to Epstein-Barr virus producer and nonproducer lymphoma cells in culture.

Adenine arabinoside (ara-A) at a concentration of 5-10 micrograms/ml inhibited the multiplication of two Epstein-Barr virus (EBV) producer lymphoblastoid cell lines B . 95-8 and P3HR-1. The nonproducer EBV genome carrier cell line, Raji, and the EBV negative cell line, Ramos, were not significantly affected. The cytotoxicity of ara-A to Ramos, Raji and P3HR-1 cells increased in the presence of 1 . 10(-5)M erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), an inhibitor of adenosine deaminase. EHNA alone was noncytotoxic and even had a mild stimulatory effect on cell multiplication. The level of adenosine deaminase in Raji and Ramos cells was similar to that observed in human cord blood lymphocytes, as determined by starch gel electrophoresis. A low level of adenosine deaminase was detected in P3HR-1 cells and the enzyme was absent from B . 95-8 cells. These findings indicate that in the absence of adenosine deaminase, ara-A cytotoxicity increased. Ara-A (5 micrograms/ml) and EHNA (1 . 10(-5)M) had no effect on human cord blood lymphocytes stimulated by phytohemagglutinin as measured by (3H) thymidine uptake, but had some effect on protein A-stimulated lymphocytes. Ara-A, however, inhibited the transformation of human cord blood lymphocytes by EBV, which EHNA did not inhibit. The synthesis of EBV capsid antigen in B . 95-8 cells was also inhibited by ara-A and slightly stimulated by EHNA.

Adenine↗
PubMed1983

Study of a family with Cerebrotendinous Xanthomatosis. No HLA linkage, but an informative recombination between HLA-B and Bf.

A large family with three children affected with the autosomal recessive disease of Cerebrotendinous Xanthomatosis (CTX) was studied for class I (HLA-A,B,C) and class II antigens (HLA-DR,D,SB), properdin factor B and glyoxalase. The extensive typing revealed an informative cross-over between HLA-B and Bf, indicating that Bf is located centromeric to the HLA-B locus and segregated in this family with HLA-D/DR. The parents in this family were first cousins and their parents were also first cousins. Three of their four haplotypes share B14, BfS, DR1, Dx and SB4 and may be identical by descent. The three affected children carried among them all four parental haplotypes, indicating that close linkage of the CTX locus to HLA is unlikely.

Adolescent↗
PubMed1983

The blepharophimosis, ptosis, and epicanthus inversus syndrome: delineation of two types.

The blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES) is rare and autosomal dominant. A family is presented and analyzed together with 38 kindreds with BPES reported in the literature. The results demonstrate the existence of two types of the syndrome: type I with infertility in affected females, and type II which is transmitted by females and males. The two entities are further differentiated by incomplete penetrance only in type II and by differences in the sex ratios of the affected children. Female infertility in type I is a predominant symptom, and the distinction between the two types is of importance for genetic counseling.

Adult↗
PubMed1983

Replacement of gentamicin by amikacin as a means of decreasing gentamicin resistance of gram-negative rods in a neonatal intensive care unit.

The emergence of resistance in bacteria that colonize infants in a neonatal intensive care unit (NICU) is of great concern and a serious therapeutic problem. During the years 1980 to 1981, continuous surveillance of bacterial colonization was carried out on 499 infants admitted to the NICU of the Beilinson Medical Center. Antibiotic sensitivity testing was performed on all organisms isolated. At the end of 1980 and the beginning of 1981, an increased number of gram-negative rods became gentamicin-resistant. It was assumed that the discontinuation of gentamicin usage and replacement with another aminoglycoside, amikacin, would bring about a reduction in gentamicin resistance. Replacement of gentamicin by amikacin resulted in a significant decrease in gentamicin-resistant Escherichia coli and Klebsiella within 3 to 6 months. The emergence of resistant strains can be detected by surveillance methods and overcome by a change in the antibiotic regimen.

Amikacin↗
PubMed1982

HLA-DR, D recombination in a kidney transplant recipient.

Immunogenetic studies of a consanguineous family revealed discordance in the inheritance pattern of the HLA-D and HLA-DR antigens in one offspring. The findings suggest a recombination between the HLA-D and HLA-DR loci in one of the paternal chromosomes. Results on segregation of B-cell alloantigens. MLC reactivity, and glyoxalase isoenzyme determination map the DR gene between the HLA-B and D loci.

Chromosome Mapping↗
PubMed1982

Association arrays for comparing familial total cholesterol, high density lipoprotein cholesterol, and triglyceride similarity in the Israeli population by country of origin.

The method of association arrays is applied to plasma total cholesterol, triglyceride, and high density lipoprotein cholesterol concentrations measured for 2485 young men and women aged 17-18 years and living in Jerusalem, and for their parents. These triad families are divided into five groups according to whether they were of mixed "origins." Stronger associations are present for all lipid and lipoprotein cholesterol variables in Asian and African families relative to families of other origins, possibly reflecting the more disciplined life-style patterns in these families relative to other families. Parent and offspring values exhibit positive association for all lipid variables in all groups. Patterns of familial similarity revealed by the association arrays are discussed in relation to historic and cultural differences among groups.

Adolescent↗
PubMed1982

Clinical variability of congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency.

Studies in 18 Jewish families from Morocco, Tunis, Turkey and Iran revealed 26 patients with congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency. The clinical expression of androgen excess varied widely in affected females, and range from solely enlarged clitoris in the mildest forms to severely hypertrophied clitoris with penile urethra and fused labial-scrotal folds in the most extreme forms of masculinization. Intermediate degrees of severity were manifested by ambiguous genitalia. There was no correlation between the degree of virilization and the signs of mineralocorticoid excess. Severe volume-induced hypertension leading to vascular accidents and death were also observed in severe as well as in mildly virilized patients, while completely masculinized females were sometime normotensive. Overt hypokalemia was present in 6 patients but was not a constant feature of hypertensives. However, all affected individuals, except for 2 infants, had very low levels of plasma renin activity suggesting that a state of volume expansion was indeed present in the majority of cases, even though changes in blood pressure did not always occur. The clinical expression of this disorder is characterized by a wide range of variability in the signs of both androgen and mineralocorticoid excess, which do not necessarily correlate with the quantity of hormones secreted.

Adolescent↗
PubMed1982

Gastric carcinoid tumors: radiographic features in eight cases.

A retrospective analysis of eight proven cases of gastric carcinoid tumors is reported with emphasis on the radiographic features. These tumors occur rarely in the stomach and have variable radiographic presentations: (1) intramural defects simulating leiomyomas, (2) multiple gastric polyps, (3) large gastric ulcers, and (4) polypoid intraluminal lesions. In this series, single submucosal lesions located in the fundus and body of the stomach were demonstrated in five patients, adjacent sessile polyps in one patient, and large gastric ulcerations in the other two patients. In five of the cases, ulcerations were clearly visualized radiographically. Three patients had pathologic evidence of metastatic dissemination. The unusual entity of argentaffin-cell adenocarcinoma of the stomach is illustrated and discussed together with a pertinent review of the literature.

Adenocarcinoma↗
PubMed1982

The clinical significance of blood-contaminated midtrimester amniocentesis.

In 706 midtrimester amniocenteses, 180 (25.5%) samples yielded blood-stained amniotic fluid (macroscopically and microscopically), 152 (21.5%) contained maternal blood, 28 (3.9%) fetal blood and 8 samples contained both maternal and fetal blood. In the 180 cases of bloody midtrimester amniocentesis, the abortion rate was 6.6% when maternal blood was found and 14.3% when fetal blood was aspirated, compared with 1.7% in controls. The amount of blood drawn did not alter pregnancy outcome. The percentage of blood amniotic fluid in amniocenteses performed before the 16th week of pregnancy was much higher (36.7%) than during and after the 16th week of pregnancy (22%). Midtrimester amniocentesis should therefore be avoided before the 16th week of pregnancy.

Amniocentesis↗
PubMed1982

Pseudodeficiency of alpha-galactosidase A.

Apparent deficiency of alpha-galactosidase A was observed in a 51-year-old, clinically healthy male, with no clinical symptoms of Fabry disease, and without excess urinary excretion of ceramide trihexoside. The deficiency, which was similar to that found in Fabry disease patients, could be demonstrated using both synthetic and natural substrates. This pseudodeficiency was transmitted in his family by classical X-linked inheritance. His wife showed enzyme activity in the normal range, two daughters were heterozygotes for this mutation as demonstrated by hair root assay, and three sons showed normal alpha-galactosidase activity. Kinetic studies in cultured skin fibroblasts indicated a five-fold increase in the apparent Km and a greater heat stability of the residual alpha-galactosidase activity when compared to controls. These data indicate that the residual enzyme activity in this mutation behaves similarly to that observed in Fabry disease patients but does not cause any clinical abnormalities.

Adolescent↗