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Biomedical subjects

K Motlík

Publications and source records attributed to K Motlík.

At least 37 records · Page 2Linked to original sources
PubMed1981

Effect of 4-cholesten-3-one on steroidogenesis and morphology of rat adrenal cortex.

The production of corticosteroids from endogenous precursors was decreased in adrenal glands of male rats fed a diet containing one per cent of 4-cholesten-3-one for 3 and 7 days. In contrast, the conversion of labelled progesterone into corticosteroids was only slightly affected as shown by the increased aldosterone to 18-hydroxydeoxycorticosterone ratio. Morphological method revealed lipoid adrenal hyperplasia developing progressively during the observation period. In the adrenal gland, the content of 4-cholesten-3-one rose slightly and, as shown in the experiment with labelled 4-cholesten-3-one, it can serve only as a weakly effective precursor of corticosteroid biosynthesis. Cholesterol content in the adrenals decreased and lipoid hyperplasia could not be explained therefore by cholesterol accumulation.

Adrenal Cortex↗
PubMed1980

Carcinoma of the prostate in specimens removed for benign hyperplasia.

Unexpected carcinoma was found in 69 cases (7.7%) our of 891 patients subjected to surgery for clinically benign hyperplasia. The incidence was higher in specimens removed by suprapubic or retropubic approach (10.2%) than by transurethral resections (2.7%). Carcinoma was found most frequently in patients aged 70 to 80 years (50.8%), next being the age group 60 to 70 years. A statistically significant prevalence of carcinoma was in th medium sized prostases (30-40 grams = 12.4%) well compared to smaller or larger prostates. The principles for a systematic topographically oriented microscopic examination are described. Morphological categories of latent carcinoma are defined as microcarcinoma, focal, multifocal or diffuse carcinoma. Adenocarcinoma was the uniform pattern of these latent carcinomas. The therapeutic attitude towards the microscopically diagnosed clinically latent prostatic carcinoma is discussed.

Age Factors↗
PubMed1977

Influence of single peroral dose of aminoglutethimide on the rat adrenal cortex.

In female albino rats force fed with a single dose of 50 mg of aminoglutethimide (AG) lipoid adrenocortical hyperplasia was found within 24 h. In addition, a marked focal increase in cytoplasmic transparency was found which ultrastructurally appeared to result from optically empty vacuoles and membrane-bound spaces. Later, an increase occurred in the translucency of the cytoplasmic matrix, mitochondrial swelling, destruction of cell membranes and disappearance of adrenocortical cells presenting as cytolysis. Some of the damaged cortical cells contained protein vacuoles with fibrillar structures and occasionally also blood cells. All such changes were associated with a marked infiltration by neutrophilic granulocytes, the most severe of them resembling an acute purulent epinephritis. Ultrastructural examination showed blood monocytes with signs of initial phagocytic activity at sites of disintegration of adrenocortical cells. Focal decrease of dehydrogenase activity was demonstrated in areas of cellular destruction, while no alteration in acid phosphatase activity was detected. Moreover, an absolute increase in corticosterone production form endogeneous precursors in vitro was found which could be partially explained by an increase in adrenocortical size. Formation of 18-hydroxycorticosterone and aldosterone from 4-14C-progesterone was decreased. However, no appreciable changes were revealed in the zona glomerulosa. From these findings it may be assumed that high doses of AG not only block the conversion of cholesterol into pregnenolone, but also injure some other cellular enzymatic systems necessary for the integrity of the adrenocortical cell.

Adrenal Cortex↗
PubMed1977

Morphological and biochemical findings in the tissues of maldeveloped gonads in 45,XX females with early primary ovarian insufficiency.

The gonads or excisions there of obtained from 13 cases of early primary ovarian failure in 46,XX females subjected to explorative laparotomy have been examined microscopically, histochemically and biochemically. Clinically, the cases were characterized by either primary amenorrhoea or by one or several spontaneous menstruations followed by amenorrhoea until operation. Roentgenologically and macroscopically, the gonads were characterized as either "steak" gonads or hypoplastic ovaries. There were no associated somatic anomalies except for slight dysplastic bone changes and/or osteoporosis. Based on morphological findings, the gonads were grouped as follows. Type A ("dysgenetic" or "aplastic") gonads characterized by a complete absence of follicular apparatus or its remnants were composed of ovarian cortical-like stroma. Some of them contained hilus cells and rete structures. Type B gonads were severely hypoplastic ovaries differing from the previous ones by the presence of various active, but predominantly inactive derivatives of the follicular apparatus, such as scarce primordial or growing follicles, corpora albicantia or atretica. Type C gonads were designated as hypoplastic sclerocystic ovaries showing a microscopical pattern similar to that of the "Stein-Leventhal ovaries", with follicles, follicular cysts and predominantly perifollicular hyperthecosis. Biochemical investigations were based on incubation studies with labelled precursors. They permitted to conclude that steroid biosynthesis was severely affected in all the gonads examined, differing most markedly from the ordinary ovarian steroid biosynthesis in the A-type gonads, and being rather similar to that observed in the "Stein-Leventhal ovaries" in the C-type ones.

Adolescent↗
PubMed1975

Dicentric Yp chromosome in a patient with the gonadal dysgenesis and gonadoblastoma.

A patient with a short stature, gonadal dysgenesis, and bilateral gonadoblastoma had 3 cell lines in the blood and in the skin: 46,X,dic (Y) (pter vector q 1 2 : : 1 2 vector pter) as a major cell line 46,X,del(Y) (q 1 2), and 45,X. The intensively flourescent distal part of the Yq was deleted in both the Y-dicentric and Yq--chromosome. Both parents had normal karyotypes.

Adult↗
PubMed1975

Familial occurrence of differentiated (non-medullary) thyroid cancer.

Differentiated thyroid cancers were found in mother and son. The diagnosis was made first in the boy where papillary and follicular cancer with lymph node involvement and lung metastatic dissemination was diagnosed at the age of 9. Treatment by surgery, radioiodine and thyroid hormones was highly effective. 1 year later, thyroid surgery was performed on his mother but the diagnosis of poorly differentiated follicular thyroid cancer was made only 4 years later when the primary tumour was already unresectable and distant metastases present. In spite of treatment, the disease followed a lethal course in the mother. The familial occurrence of differentiated thyroid cancer is extremely rare and this report is the first where neither previous radiation exposure nor familial colonic polyposis were detected.

Adenocarcinoma↗