Yoshihiro Sei

Biochemical basis of prolidase deficiency. Polypeptide and RNA phenotypes and the relation to clinical phenotypes.

Cultured skin fibroblasts or lymphoblastoid cells from eight patients with clinical symptoms of prolidase deficiency were analyzed in terms of enzyme activity, presence of material crossreacting with specific antibodies, biosynthesis of the polypeptide, and mRNA corresponding to the enzyme. There are at least two enzymes that hydrolyze imidodipeptides in these cells and these two enzymes could be separated by an immunochemical procedure. The specific assay for prolidase showed that the enzyme activity was virtually absent in six cell strains and was markedly reduced in two (less than 3% of controls). The activities of the labile enzyme that did not immunoprecipitate with the anti-prolidase antibody were decreased in the cells (30-60% of controls). Cell strains with residual activities of prolidase had immunological polypeptides crossreacting with a Mr 56,000, similar to findings in the normal enzyme. The polypeptide biosynthesis in these cells and the controls was similar. Northern blot analyses revealed the presence of mRNA in the polypeptide-positive cells, yet it was absent in the polypeptide-negative cells. The substrate specificities analyzed in the partially purified enzymes from the polypeptide-positive cell strains differed, presumably due to different mutations. Thus, there seems to be a molecular heterogeneity in prolidase deficiency. There was no apparent relation between the clinical symptoms and the biochemical phenotypes, except that mental retardation was present in the polypeptide-negative patients. The activities of the labile enzyme may not be a major factor in modifying the clinical symptoms.

Comparison of the Nuclear Contour Index (NCI) and T cell Subsets of Erythematous, Plaque and Tumor Lesions in Patients with Mycosis Fungoides (MF)

Using monoclonal T cell antibodies, we compared T cell subsets of skin infiltrates with the nuclear contour index (NCI) of pan T cells of skin infiltrates from erythematous, plaque and tumor lesions in the same patients with mycosis fungoides (MF). In all lesions, the majority of the skin‐infiltrate population were T cells; helper T cells were especially dominant in the plaque and tumor lesions. The NCI of the T cells in skin infiltrates increased in parallel with advancing stages of the lesions in the same patient. The NCI data for T cell and T cell subsets in different stages of lesions in the same patient were similar to data from different stages of lesions in different patients. Therefore, even in tumor stage patients, topical treatment should be selected in accordance with the cytological stage of their lesions.