Biomedical subjects
Publications and source records attributed to H Betuel.
In 94 children suffering from cystic fibrosis, no abnormal frequencies of HLA markers of the A and B locus were observed in comparison with the distribution of these antigens in control series. Furthermore, the HLA genotypes of seven pairs of diseased sibs are incompatible with the hypothesis of a closed linkage between CF--an autosomal recessive transmitted disease--and HLA.
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New data are presented concerning the relationship between NPC and HLA antigens among Chinese. When attention is confined to newly diagnosed cases, it can be shown that, apart from the increased risk associated with the joint occurrence of A2 and B-Sin 2, there is also an increased risk associated with BW17 and a decrease in risk associated with A11. Among long-term survivors, however, BW17 is appreciably decreased, whereas A2 in the absence of B-Sin 2 or BW17 is increased. Among Malays, a non-Chinese group, there is an excess among NPC patients of a locus A blank, a blank which is probably associated with the AW19 complex.
Human peripheral blood T cells bearing receptors for the Fc portion of immunoglobulins were characterized by the formation of double rosettes with sheep red blood cells and IgG-coated chicken erythrocytes (EA). Treatment of cells by anti-"Ia-like" antisera inhibits the binding of EA. Inihbition appeared to be specific since anti-HLA-A and HLA-B antibodies did not inhibit the formation of EA rosettes, whereas F (ab')2 fragments of anti-Ia-like IgG were found to be as potent inhibitors as the whole IgG. This result shows that in human and in mice, Ia-like determinants arepresent, close to Fc gamma receptors, on the surface of the T lymphocytes bearing such receptors.
Seventy-five patients with multiple sclerosis (MS) were treated for complement components C3, after factor B, C4, and tested for HLA-A and B-determinants. Levels of IgG, IgA, IgD, IgE and titres of measles antibodies were also determined. Correlations between these immunological values and HLA determinants could be obtained in siblings, parents and/or children of the patients in 13 families. B18 frequency is strongly associated with the hypocomplementaemic group (x2 = 8.9). An association of B18 with the population of cases with low B levels is also found (x2 = 8.02). Familial data showed that low C3 and/or low B levels are associated with the HLA haplotyes, especially with those containing B18. A "complement abnormality susceptibility gene", linked to the HLA genes, is postulated. Infections are significantly more frequent in families of hypocomplementaemic MS, the existence of a genetic immunodeficiency affecting the synthesis of the complement components, linked to the HLA determinants. In 1 case studied in this article, a heterozygous C2 deficiency linked to HLA-A10, B18 was found and might confirm this hypothesis.
After centrifugation of 450 ml-CPD-whole blood, 125 ml of packed red cells are diluted to 50 percent with saline (pH 7, 2). To remove leukocytes the diluted blood is filtered at room temperature through a newly devised column packed with cotton wool disks. 200 ml of red blood cells suspension are recovered and contain less than 5.10(6) leukocytes. Appropriate controls show that: 1. The filtered blood contains no pyrogen; 2. The red blood cells have a normal osmotic resistance; 3. The suspension can be maintained at 4 degrees C up to 5 days before transfusion without cellular damage.
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HLA antigens were purified from urines of kidney transplanted patients, HLA was recovered as a single peak of 45,000 mol wt that was dissociated into beta2-microglobulin and a 33,000 mol wt fraction bearing the allospecificity. The purified fractions contain carbohydrates but no lipids. Electrophoretical mobility and the relative salt concentration of eluting buffers in DEAE-Sephadex chromatography were determined for six antigens of the A locus and seven antigens of the B locus. Isolectric points of antigens A1, A2, A9, and B12 were measured. Physiochemical characteristics of HLA purified from urine appear to be similar to those of papain-solubilized cell membrane HLA. Urinary HLA was shown to originate from serum and not from renal or ureteric tissue.
HL-A antigens were found with similar frequency in ninety vitiligo patients and in 341 healthy controls. However there was a significant correlation between HL-A13 and vitiligo with antithyroid antibodies. This supports the concept that vitiligo is a syndrome rather than a disease.
The authors describe the results of immunological assay of complement factors C3, C4 (the usual path of activation of complement) and of B factor (the alternate path of activation) in 61 multiple sclerosis patients not receiving corticoids, 52 normal controls and 217 patients with other neurological disorders. Hypocomplementaemia (fall in factor C3 related to a fall in total haemolytic activity) was found in 29.5 p. 100 of the patients not on corticotherapy at the first assay, and in 36 p. 100 of the patients when repeated assays were carried out. Hypocomplementaemia is significantly more frequent in multiple sclerosis than in the normal population (0 p. 100) and in neurological patients (9.6 p. 100). In 13.1 p. 100 of the multiple sclerosis patients there was a decrease in B factor: 50.3 p. 100 of the multiple sclerosis patients exhibited no quantitative abnormality of the main factors of complement (normocomplementary multiple sclerosis). The group of multiple sclerosis patients with hypocomplementaemia was characterized by the incidence of other abnormalities in the complement system: cleavage of the C3 factor and a fall in B factor in 60 p. 100 of the cases. A more frequent increase in IgE and measles antibodies was found also while the normocomplementary multiple sclerosis patients more frequently had higher levels of IgA. Genetically, the group with hypocomplementaemia is related to a significant increase in the incidence of the HL-A W18 group while the normocomplementary multiple sclerosis patients appear closely related to the HL-A7 group. Familial investigations show that hypocomplementaemia is usually present in the ascendents and collaterals and that it seems to be transmitted with the HL-A haplotypes. Four families gave evidence of transmission with the W18 group. This transmission sometimes occurs together with transmission of an increase in IgE and/or of measles antibodies. In two pedigrees, one of the ascendents carried in his serum an activator of the alternate path of complement. There does not appear to be any prognostic difference between the two groups. In multiple sclerosis with hypocomplementaemia, the facts suggest a complex immunological abnormality, transmitted genetically to the subject and existing prior to the illness, comprising both elements of deficient and excessive immune response. The recognized presence of a gene of immunological reactivity and of genes of synthesis of complement on the 6th chromosome, in proximity with genes of histocompatability (HL-A and M.L.C.) provides a theoretical basis for this supposition.
Previous reports have demonstrated an association between the HL-A system and risk for nasopharyngeal carcinoma among the Chinese in Singapore. The present paper describes an investigation of HL-A profiles among NPC cases and non-NPC controls from Tunisia, to determine whether a similar association occurs in a different ethnic group. A total of 109 NPC cases and 84 controls were typed. At the second HL-A locus the results were similar to those found in Singapore, but the effect was less marked and did not reach high statistical significance. At the first HL-A locus, no association between A2 and NPC was found, in contrast to the Singapore results.
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An enzyme, guanyl cyclase, which catalyzes formation of CYCLIC 3',5'-GMP from 5'-GTP, has been identified in human peripheral lymphocytes. The activity in lymphocyte homogenate is 14 pmol (min 10-7 lymphocytes). No activity is detected in red blood cells, and the amount found in platelets is very low. The properties of this enzyme are very close to those reported for other guanyl cyclases studied in other tissues: namely, its intracellular localization, its requirement for cation Mn-2+, its inhibition by Hg-2+, Zn-2+ and by nucleotides especially 5'-ATP. No change in enzyme activity occurs when phytohemagglutinin P is added to disrupted lymphocytes. However, when the mitogen is incubated with intact cells, guanyl cyclase activity increases in a few minutes.