Biomedical subjects

D Schreiber

Publications and source records attributed to D Schreiber.

At least 109 records · Page 6Linked to original sources

PubMed1976

Hypothalamic hypothyroidism and XXY/XY sex chromosome mosaicism. Report of a case.

An 18-year-old boy with clinical features of Klinefelter's syndrome in whose case the buccal smear was chromatin-negative and chromosomal analysis of peripheral blood revealed 46 XY karyotype is described. Diagnosis was confirmed by demonstration of an XXY cell line in cultured skin fibroblasts. Low circulating thyroxine levels were found despite absence of clinical hypothyroidism, and TSH was barely detectable. The studies are consistent with an isolated deficiency of thyrotropin-releasing hormone in a patient with XY/XXY mosaicism.

Adolescent↗

PubMed1976

[Experimental heart tumours in rats (author's transl)].

In continuation of previous own investigations 68 heart tumours including 46 early stages were found in the heart of 590 BD IX rats systematically examined after treatment with methylnitrosourea (MNU) or ethylnitrosourea (ENU). The tumour incidence was about 40% in animals treated by repeated intravenous or intraperitoneal injections of 20 mg per kg body weight MNU. These experiments are suitable for the study of early stages and the histogenetic origin of heart tumours. At present MNU in addition to triazenes (table 5) belongs to the most powerful carcinogens which affect the heart in rats.

Animals↗

PubMed1975

[Beta-glucuronidase activity and morphological alterations in the nervus trigeminus of the rat after application of the neurotropic carcinogen ethylnitrosourea (author's transl)].

Newborn rats were given subcutaneuously 85 mg ethylnitrosourea/kg body weight. The trigeminal nerves of the grown up and of infantile animals were histologically examined and their beta-glucuronidase activity biochemically determined. These activities were compared with those of untreated control animals of the same age. More than 50% of the enzyme values of the experimental animals were significantly higher than those of the controls. Most of the elevated activities were encountered in the central part of the nerve and consisted mainly of the pooled soluble and bound fraction of the enzyme. There is a positive correlation between the level of the enzymatic activity and the degree of morphological changes. An increased enzymatic activity was found in almost 100% of the tumor bearing nerves. Moreover such increased activities were found in a considerable number of histologically tumor free nerves. Ruling out other causes, for instance inflammation, it may be assumed that the increased activity of beta-glucuronidase in the trigeminal nerve of the rat after application of ethylnitrosourea is an expression of its carcinogenic effect and precedes the histologically visible alterations.

Animals↗

PubMed1975

[Pathobiology of carcinogenesis and the growth of neoplasms].

The importance of carcinogenicity by chemical substances is reviewed with regard to the increasing number of human neoplasms (1955: 39703; 1972: 62556) in the German Democratic Republic. The organotropic action of some carcinogens, the transplacental tumour induction, the endogenous formation of oncogenic N-nitroso compounds from inactive precursors in the stomach of experimental animals, and the role of carcinogens derived from plants are analysed. Up to now it remains uncertain, whether DNA and RNA viruses responsible for tumour development in different species of animals may effect tumour growth in human beings as well.

Animals↗

PubMed1973