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Biomedical subjects

D B Amos

Publications and source records attributed to D B Amos.

At least 145 records · Page 8Linked to original sources
PubMed1972

Renal transplantation between HL-A identical donor-recipient pairs. Functional and morphological evaluation.

16 patients underwent renal transplantation from a sibling donor who was prospectively determined to be ABO compatible and HL-A identical with the recipient. Unidirectional mixed leukocyte reactions were performed; in each instance, lymphocyte stimulation in either direction was not observed. The plasma creatinine 10-68 months after transplantation in these 16 patients ranged between 0.9 and 1.9 mg/100 ml. The creatinine clearance ranged from 48 to 113 ml/min, and the blood urea nitrogen (BUN) ranged between 12 and 35 mg/100 ml. Urine protein excretion varied from 0.11 to 1.86 g/day. Six patients exhibited no detectable clinical episodes of acute rejection; they were treated with azathioprine alone and each of them demonstrated normal or near normal renal histology when biopsy specimens were obtained more than 6 months after transplantation. Nine patients experienced acute rejection episodes that required the use of steroid therapy. The severity of these rejection episodes was variable; they included a mild reduction in renal function with an immediate steroid-induced restoration of function and eventual discontinuance of steroid therapy to severe reduction in function requiring prolonged and moderate doses of steroids without return to normal renal function. Renal histological observations in this group ranged from mild to marked cellular and structural changes which fit the criteria of the rejection. One patient demonstrated a gradual loss of renal function with heavy proteinuria. Biopsy of this allograft demonstrated the recurrence of original disease, i.e., lobular glomerulonephritis. The marked variability in the clinical course and allograft morphology in these 16 patients could be explained by antigenic differences at non-HL-A loci. The presence of minor histocompatibility loci has been well documented in other mammalian species and they are most certainly present in man. The need for their identification and definition is stressed.

Adult↗
PubMed1971

Human lymphocyte antigen reactivity modified by neuraminidase.

Human lymphocytes treated with neuraminidase (from Vibrio cholera) are more susceptible to lysis with antiserums directed against HL-A antigens in the cytotoxicity test than are the corresponding cells incubated in buffer. Enzymetreated cells are also lysed by antibodies other than those directed against HL-A, but control cells are not. The extra sensitivity to antibody disappears after 2 to 6 days in tissue culture.

Antigen-Antibody Reactions↗
PubMed1971

The immunogenicity of human HL-A haplotypesas measured by skin graft survival times and mixed leukocyte reactions.

The immunogenicity of the haplotypes in 30 families was measured by survival of skin grafts between selected paired family members. These families were genotyped for HL-A using 57 selected cytotoxic alloantisera defining HL-A 1-12 as well as other nondefined specificities. Mixed leukocyte reactions were also studied in this series and the correlations between the mixed leukocyte reactions with skin graft survival times, individual HL-A specificities, and the number of incompatible HL-A alleles are reported. Comments concerning the interpretation and quantitation of the mixed leukocyte reactions are discussed.

Alleles↗
PubMed1971

Three closely linked genetic systems relevant to transplantation.

The concept that antigens of a major histocompatibility locus (HL-A), the mixed leukocyte reaction, and the rejection of a graft are expressions of the same genetic region has been generally accepted. WE HAVE PRESENTED EXPERIMENTS THAT CHALLENGE THE ABOVE CONCEPT AND SUGGEST THAT THE REJECTION TIME OF SKIN AND ORGAN TRANSPLANTS IS DEPENDENT ON IMMUNIZATION AGAINST THE PRODUCTS OF TWO, AND POSSIBLY THREE, SEPARATE, BUT CLOSELY LINKED, GENETIC SYSTEMS: HL-A, mixed leukocyte reaction (MLR-S), and hypersensitivity delayed reaction (HDR). The findings presented and discussed here suggest that the HL-A antigens are not the primary factors involved in the cell-mediated component of allotransplantation, and that these antigens and phenotypes of the mixed leukocyte reaction can only be used as a guide in predicting the survival of allografts that are obtained from unrelated donors.

Female↗