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Biomedical subjects

A Persitz

Publications and source records attributed to A Persitz.

4 recordsLinked to original sources
PubMed1985

Meiotic association between the XY chromosomes and unpaired autosomal elements as a cause of human male sterility.

Intimate association between autosomal translocation trivalents and XY bivalents at pachytene was observed in a majority of cells of two men ascertained through primary sterility and found to be heterozygous for a 14;21 Robertsonian translocation. The association, studied by light and electron microscopy of spread first spermatocytes, was between the unpaired short arms of the normal chromosomes of the translocation trivalent and the differential axes of the XY chromosomes. In a minority of cells, this contact was not established, or not maintained, as alternative combinations between the elements available for non-homologous pairing were realized. Following a suggestion of Lifschytz and Lindsley (1972), sterility in these patients was attributed to spermatogenic arrest caused by physical contact of sex chromosomes with autosomal material and consequent interference with the normal metabolism of the sex chromosomes. Autosomal aberrations and polymorphisms, which lead to the presence of unpaired segments at meiosis, may thus play a critical role in a general mechanism of chromosomally-derived male sterility. It is proposed that such a mechanism may also be instrumental in the initiation of reproductive barriers in nature.

Chromosomes, Human, 13-15↗
PubMed1978

Ultrastructural features in normal and hyperplastic postmenopausal endometrium.

Seven samples of postmenopausal endometrium were studied by electron microscopy. Four samples were diagnosed as adenomatous hyperplasia (2 of which were atypical) and 3 as normal postmenopausal endometrium. The most striking ultrastructural features of hyperplastic endometrium were: numerous nucleoli, deep nuclear membrane infoldings, increased nucleocytoplasmic ratio, prominent and enlarged RER closely associated with mitochondria and nuclear membrane, abundant free ribosomes and marked network microfilaments. In the case of atypical adenomatous hyperplasia, the protruded intraglandular proliferating epithelial cells exhibited more atypical features than the epithelial cells of the glandular lining, suggesting a more advanced degree of anaplastic change. The characteristic features of the normal postmenopausal endometrium were: paucity and random distribution of the cytoplasmic organelles, the presence of large cytoplasmic vacuoles and short, blunt microvilli. Secretory vacuoles opening into the lumen of the gland were found in one case of cystic atrophy of a normal postmenopausal endometrium. Collagenization was found in the stroma of both groups, although predominantly in the normal postmenopausal endometrium. In 2 cases of adenomatous hyperplasia stromal cells with vacular cytoplasm were found. The significance of these findings, as related to their importance as precursor stages of endometrial cancer (in the cases of adenomatous and atypical adenomatous hyperplasia); as involutional manifestations (in the cases of normal postmenopausal endometrium); and as related to the absence of cyclic activity (in both groups) is briefly discussed.

Cell Nucleus↗