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Biomedical subjects

R Sharon

Publications and source records attributed to R Sharon.

At least 91 records · Page 5Linked to original sources

Histocompatibility determinants in Israeli Jewish patients with coeliac disease: population and family study.

The association between HLA and coeliac disease (CD) was studied in the Jewish population of Israel. A total of 112 patients were typed for HLA-A,B,C antigens, including 67 patients whose families were typed in order to deduce the genotypes. Forty-seven patients were typed for HLA-DR antigens. The HLA-A,B,C data show a pattern of association, which is similar to that found in European CD patients: HLA-B8 is increased, although to a lower degree; a suggestive, insignificant increase for Aw30, B13 and Cw6 and a decrease of Bw35 were noted. The DR antigens DR3 and DR7 are associated with CD in the Jewish population. An excess of DR3/DR7 heterozygotes was noted. The data from family and population studies support a model in which two different HLA-DR associated genes are interacting.

Celiac Disease↗

Relationship between formaldehyde-related antibodies and cross-reacting anti-N-like antibodies in patients undergoing chronic haemodialysis.

An attempt was made to determine the sequence of events leading to the production of two distinct antibodies in patients with chronic renal failure who regularly undergo haemodialysis with formaldehyde-resterilizable dialysis units by Multipoint (UK) or Cordis (USA). A distinct pattern emerged-namely, the production of anti-formaldehyde red cells started about six months after the beginning of haemodialysis treatment. Only when the titre of these antibodies reached 64 or 128 another, apparently cross-reacting, antibody appeared which reacted like an anti-N antibody. A strong direct antiglobulin reaction was found to be positive for formalin-treated red cells after five minutes' contact with specific antibody, indicating a high affinity of the antibody fo the formalin-altered red cell.

Antibodies↗

HLA-DRw4 in pemphigus vulgaris patients in Israel.

Pemphigus vulgaris (PV) is relatively common in Jews. Three HLA antigens were significantly more frequent in 39 Israeli Jewish PV patients than in controls A26 - 59% vs 20%; Bw38 - 61% vs 20%; and DRw4 - 90% vs 38%. The joint occurrence of A26-Bw38-DRw4 was observed in 46% of PV patients and in 10% of controls. Similar results were recently reported for Jews in the Los Angeles area. Yet, when our patient sample was grouped into Ashkenazi and non-Ashkenazi Jews, it was evident that each of the three antigens had a higher frequency both in Ashkenazi patients and controls as compared to non-Ashkenzai. The relative risk for DRw-4 in Ashkenzim was 33.8 as compared to 14.4 in the total sample of Israeli PV patients. The phenotype A26-Bw38-DRw4 was present in 57% of Ashkenazi patients and in 13% of controls. Ashkenazi Jews have the highest prevalence of PV, and HLA associations were strongest with Ashkenazi PV patients. These associations were with three antigens, all of high frequency in that group.

Female↗

Detection of penicillins in the sera of 'healthy' blood donors.

10,853 sera, collected from 'healthy' blood donors during the period December 1977 to May 1979, were tested for the presence of penicillinase-sensitive penicillins by a bioassay technique using Bacillus subtilis ATCC 6633 as test organism. Their presence could be demonstrated in 30 sera (0.27%), at concentrations equivalent to 0.2--4.0 micrograms/ml of penicillin G. The implications of these findings are discussed, particularly the possibility of their relationship to nonhemolytic adverse reactions to transfusion.

Bacillus subtilis↗

Presence of aspirin in blood units.

2,655 blood units collected from healthy voluntary donors selected according to the criteria of the International Society of Blood Transfusion were tested for the presence of aspirin. This drug was found in 6% of the samples at concentrations ranging from 10 to 200 microgram/ml. The clinical implications of these findings are discussed. We also report a case of allergic reaction which could probably be related to the transfusion of blood containing aspirin.

Adult↗

The Duffy blood group system in Israeli Jews and Arabs.

The distribution of the Fy gene was studied in 1,207 Israeli Jews and 509 Arabs. The Fy(a--b--) phenotype (FyFy) was observed in Moslem, Christian and Druze Arabs, and in Jewish immigrants from Yemen and Iraq, but not in Sephardi or Ashkenazi Jews. The Fy gene frequencies in Arabs and Jews were compatible with historical evidence of interactions with native African and admixed regional populations. Compared with Rho (cDe) and Jsa, Fy(a--b--) is a more useful genetic marker for recognizing African admixture in Middle Eastern populations.

Blood Group Antigens↗

Antiformaldehyde and anti-N-like antibodies in hemodialysis patients.

Seventy-one hemodialysis patients were tested for antibodies to red blood cell antigens; 19 of the 71 had been treated with formaldehyde-sterilized dialysis membranes. The sera of 3 (16%) of these 19 contained anti-N-like antibodies and those of 17 (89%) contained a second agglutinin specific for formaldehyde-treated red blood cells. Anti-N-like and "antiformaldehyde" antibodies appear to be serologically distinct. We suggest that residual formaldehyde in formaldehyde-sterilized dialysis membranes reacts with red blood cells to form an immunogen responsible for antiformaldehyde in patients treated with these membranes.

Antibodies↗

Two modes of excision repair in toluene-treated Escherichia coli.

In toluene-treated Escherichia coli incision breaks accumulate during post-irradiation incubation in the presence of adenosine 5'-triphosphate (ATP). It is shown that incised deoxyribonucleic acid (DNA) is converted to high-molecular-weight DNA during reincubation in the presence of the four deoxyribonucleoside triphosphates (dNTP's) and nicotinamide adenine dinucleotide (NAD). This restitution process is ATP independent and N-ethylmaleimide insensitive and takes place only in polA+ strains. It is defective in strains carrying a mutation in the 5' leads to 3' exonucleolytic activity associated with DNA polymerase I. Repair of accumulated incision breaks differs from repair in which all the steps of the excision repair process occur simultaneously or in rapid succession. The latter is observed if toluene-treated E. coli are incubated immediately after irradiation in the presence of the four dNTP's, NAD, and ATP. It is shown that under these conditions dimer excision occurs to a larger extent than during repair of accumulated incision breaks and that, except in strains defective in polynucleotide ligase, incision breaks do not accumulate. This consecutive mode of repair is detectable in polA+ strains and at low doses also in polA mutants.

Adenosine Triphosphate↗