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Biomedical subjects

A F Michael

Publications and source records attributed to A F Michael.

263 records · Page 15Linked to original sources
PubMed1966

Tryptophan metabolism in a patient with phenylketonuria and scleroderma: a proposed explanation of the indole defect in phenylketonuria.

Phenylketonuria and severe focal scleroderma were observed in a white male child. This is the first instance in which the association of these two rare disorders has been reported. Studies carried out on this patient provide a possible explanation for the abnormalities of indole metabolism in phenylketonuria. On an unrestricted diet, when serum phenylalanine levels were elevated, excessive urinary excretion of indolic tryptophan metabolites was seen 18-24 hours after oral tryptophan loading, and tryptophan was demonstrable in the stool. This was not observed when the serum phenylalanine was within normal limits on a low phenylalanine diet. Impaired intestinal tryptophan absorption secondary to elevated serum phenylalanine, by providing tryptophan substrate for bacterial degradation to indolic compounds which are absorbed and excreted in the urine, may partially explain the abnormalities of indole metabolism in phenylketonuria.

Chromatography, Paper↗
PubMedDate not supplied

Analysis of renal cell populations using monoclonal antibodies.

Monoclonal antibodies have proved invaluable in identification and characterization of hemopoietic cell surface macromolecules. We have used a number of these monoclonal antibody probes for immunohistochemical analysis of interstitial cell populations in diseased human kidney tissues and in certain prototypic cutaneous cellular immune reactions. The studies demonstrate that the relative proportions of T-cell subpopulations present in graft rejection (OKT8+ exceeding OKT4+) differ from those observed in drug nephrotoxicity and end-stage kidney disease. In this regard rejection resembles graft versus host disease of skin but not delayed-type hypersensitivity. However, analysis of cell populations in interstitial infiltrates from various forms of chronic renal disease (glomerulonephritis, end-stage renal disease of varied etiologies) failed to demonstrate any unique or characteristic profile. These studies led to the recognition that certain monoclonal antibodies directed against B- and leukemic cell surface antigens also bind to normal renal cells and that nephron development in the human fetus is characterized by differential binding of these probes.

Antibodies, Monoclonal↗