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Biomedical subjects

J Marek

Publications and source records attributed to J Marek.

At least 271 records · Page 15Linked to original sources
PubMed1977

Inhibitory effect of various cytostatics and cycloheximide on acute experimental pancreatitis in rats.

Cycloheximide, 5-azacytidine, and 4-methoxybenzoyl-beta-bromoarylate (Cytembena) block the development of experimental acute pancreatitis in rats when mediated by the administration of 5% bile solution into the pancreas in vivo. Six hours after drug treatment the pathological changes, evaluated macroscopically or using histological sections of the pancreas, were significantly decreased. The drugs affected the amount of abdominal fluid and lowered its lipase and amylase activity. The known inhibitory mechanism of the active drugs and the possible advantage of cycloheximide for clinical use are briefly mentioned.

Acrylates↗
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↗
PubMed1976

Insulin secretion and glucose tolerance in acromegaly.

Thirty patients with active acromegaly were divided into five groups according to the results of their IRI and blood glucose curves in the course of oral glucose tolerance test. Young acromegalics with short duration of acromegaly had grossly exaggerated IRI response with the peak in the first half-an-hour and the flat blood glucose curve. In the second group the peak of IRI response was in the first hour and the blood glucose curve rose to high values in the early stage after the glucose load. The IRI response in the third group was still exaggerated but delayed and the diabetic type of blood glucose curve was found in some of these patients. Acromegalics with overt diabetes mellitus lost their exaggerated IRI response and the IRI curves were flat in those with more advanced disturbance of glucose tolerance. It was suggested that the groups described might represent individual stages in the development of diabetes mellitus in acromegaly. Unclear position in this scheme is kept by the group of active acromegalics with IRI response in normal limits and glucose tolerance unimpaired.

Acromegaly↗
PubMed1976

[Functionally active tumor of the carotid body].

The clinical and biochemical pictures of a woman of 60 suffering from paroxysmal hypertension appeared to be clear evidence of a functionally active neoplasm of the sympathoadrenal tissue. A surgical operation ruled out the possibility of the tumour being localized adrenally so that the actual site of noradrenaline release was never found during the patient's lifetime. An autopsy discovered the presence of a carotid body tumor sized. 4.5X3X3 cm. The histological picture, electron microscopy as well as the positive isolation of noradrenalin all seemed to offer clear evidence of a functionally active tumour although the chromaffin reaction was negative. This is just additional evidence of the fact that the carotid body does belong among sympathetic paraganglia and that the chromaffin reaction is not sufficiently sensitive and reliable either for the determination of biogenic amines in the tissue or for a clear, unequivocal detection of functionally active tumours of the sympathetic.

Autopsy↗