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Biomedical subjects

D Bernoco

Publications and source records attributed to D Bernoco.

33 records · Page 2Linked to original sources

Five subtypic specificities of the Bw22 complex in four racial groups.

Five subtypic specificities of Bw22 were defined using 38 informative local and Seventh Histocompatibility Workshop sera: Bw54, 22.2, J2, Bw42, and a new Bw22 associated antigen Te90. The previously defined specificity, 22.1, associated with Cw3, could not be distinguished from Bw54 in this study. Marked restriction in the distribution of four Bw22 specificities (Bw54 excepted) in white, Mexican, black, and Oriental populations was described and provided supporting evidence for the identification of these antigens.

Black People

Autoantibody against B lymphocytes.

The sera of 20 out of 99 (20%) normal males and females were shown to have antibodies that kill their own B lymphocytes. The sera were specifically cytotoxic to B lymphocytes and not T lymphocytes. Allogeneic B lymphocytes were also killed by these autocytotoxins. Maximum killing of B lymphocytes occurred when the incubation temperature in serum was 5 degrees C and complement incubation temperature was 20 degrees C. Under these cold conditions, some sera reacted up to a dilution of 1/16. These results suggest that positive B-lymphocyte crossmatches found in kidney transplantation do not detect alloantibodies. Since the B-cell autoantibodies tend to appear at the time of immunisation, their role as autoregulators of the antibody response is an intriguing possibility.

Autoantibodies

Structural heterogeneity of C2 Complement protein and its genetic variants in man: a new polymorphism of the HLA region.

A zymogram method, following thin-layer isoelectric focusing in a polyacrylamide gel, allows resolution of the lytic activity of serum C2 complement protein in a spectrum of molecular forms. This spectrum is characteristic in each of the species studied (man, rhesus monkey, guinea pig, and hamster). Moreover, two different alternative patterns are observed in man: each of the six major lytic bands characteristic of the most common pattern (herein designated C2(1) is duplicated in the least common pattern (C2(2-1), with an additional band displaced cathodally by not more than 0.04 pH unit. Distribution of phenotypes C2(1) and C2(2-1) in a Caucasion population is in agreement with the hypothesis that they are controlled by two alleles, C2(1) and C2(2), with frequencies 0.96 and 0.04 +/- 0.01. Segregation studies show that the two alleles are codominant and identify a locus in the HLA region. No recombinants with HLA-B were detected among 27 informative meioses, generating a cumulative lod score of 6.321 at equals 0. These findings suggest that the individuals with the C2-deficient trait might be interpreted as homozygotes for a third and rarest amorph C2 degrees of the same locus.

Animals

Ninety-five percent probability of paternity with HLA, ABO and haptoglobins.

Using HLA tissue typing as the basic genetic test along with ABO and haptoglobin typing, it is generally possible either to exclude a putative father conclusively or, in nonexclusion cases, to assign a greater than 95% probability of paternity. In 22 of 53 nonexclusion cases, the putative father had a probability of paternity above 99% based on these genetic tests.

ABO Blood-Group System

Heterogeneity and linkage of equine C4 and steroid 21-hydroxylase genes.

The fourth component of complement (C4) is polymorphic in most species studied, and is encoded by a gene or genes within the MHC. In man and mouse there are two closely linked C4 and steroid 21-hydroxylase (21-OH) genes. Therefore we have used Southern blotting to determine whether equine C4 and 21-OH genes are linked. C4 restriction fragment length polymorphism (RFLP) was found with the enzymes EcoRI and BamHI. Comparison of the sizes of EcoRI-digested fragments of genomic DNA hybridizing with C4 and 21-OH probes revealed that equine C4 and 21-OH genes are separated by no more than 13 kb. Further, there is no evidence of C4 and 21-OH gene duplication in the horse. Segregation of ELA and different polymorphic forms of equine C4 suggest that C4 and 21-OH genes are within the MHC. It is likely that equine MHC supratypes will provide improved markers of disease susceptibility.

Animals