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Biomedical subjects

H Breuer

Publications and source records attributed to H Breuer.

At least 127 records · Page 7Linked to original sources
PubMed1979

Liver cirrhosis and oestrogen metabolism--perfusion studies with cirrhotic rat livers.

1. Radioactive oestrone and oestradiol-17 beta were perfused through normal and cirrhotic livers of rats. Liver cirrhosis had been induced by a combined application of carbon tetrachloride and azathioprine. 2. The hepatic uptake of both oestrogens by cirrhotic livers was reduced; the uptake of oestrone was more affected than that of oestradiol-17 beta. 3. The pattern of oestrogen metabolites indicated a reduction of the sulphotransferase activity in cirrhotic livers. The activity of other enzymes of oestrogen metabolism were similar in normal and cirrhotic livers. 4. The amount of oestrogen glucuronides excreted into the bile was significantly less in cirrhotic livers although the bile volume was larger in cirrhotic than normal livers. 5. The release of oestrogen metabolites into the circulating medium was considerably higher during perfusion of cirrhotic livers. From the findings presented here it is concluded that the turnover of oestrogens is slower in cirrhotic than in normal livers. Moreover, it may be speculated that the distribution volume of the oestrogen metabolites is smaller in rats with liver cirrhosis, due to a disturbed enterohepatic circulation. This results in higher oestrogen concentrations in extracellular fluids, thus supporting the concept of hyper-oestrogenism in liver cirrhosis.

Animals↗
PubMed1979

[Effect of 17-alpha-hydroxyprogesteronecapronate on sodium excretion and the renin-angiotensin-aldosterone-system in humans].

In seven healthy male subjects, a natriuretic effect of 17 alpha-hydroxyprogesterone caproate (17 alpha-OHPC) was demonstrated. Three of these subjects were kept on an uncontrolled diet and were examined over a period of 12 days. To the remaining four subjects, a single dose of 250 mg 17 alpha-OHPC was given intramuscularly after four days of intake of a chemically defined diet (Vivasorb). In this second test procedure, blood samples were taken in the recumbent position every two hours throughout a period of 12 h after the injection. For two more days and during the days before the administration of 17 alpha-OHPC, blood was taken at 8 a.m. before getting up from bed in same intervals, urine was collected for analysis of sodium and potassium excretion. During the first 12 h after the injection of 17 alpha-OHPC, the urinary sodium/potassium ratio significantly increased in all subjects. Plasma renin activity showed no characteristic changes at this time, whereas the plasma concentrations of aldosterone and cortisol decreased. The decrease of cortisol concentration started immediately after the injection and was more pronounced than that of plasma aldosterone. During the following 36 h, renin activity as well as aldosterone and cortisol concentrations in plasma showed an increase; in contrast, the sodium/potassium ratio decreased. On the basis of these results, the following effects of 17 alpha-OHPC are discussed: (1) an acute natriuresis which may be due to a competitive inhibition of aldosterone at the renal tubules, and (2) an inhibition of pituitary ACTH secretion or of adrenal steroid biosynthesis.

Adult↗
PubMed1978

A highly sensitive method for the demonstration of carcinoembryonic antigen in normal and neoplastic colonic tissue.

A highly sensitive method for the immuno-histochemical localisation of carcinoembryonic antigen (CEA) is described. This method is based on the binding of a peroxidase-antiperoxidase complex (PAP) to anti-CEA antibodies by means of an anti-gamma-globulin which reacts with both the anti-CEA and the antiperoxidase antibodies. Using the technique described here, CEA was localised in conventionally processed normal and cancerous colonic tissue. In normal as well as in neoplastic tissues, a CEA-specific staining of cell membranes and cytoplasm was demonstrated. In frozen sections of normal colonic tissue CEA was found even at high dilutions of the first antibody; this indicates the high sensitivity of the method. The applicability of the method to conventionally processed and thereby well preserved tissue specimens opens the possibility to identify CEA by light microscopy even at very low concentrations.

Animals↗
PubMed1978

[Biosynthesis of C19- and C21-steroids in tissue slices of paraganglioma and pheochromocytoma (author's transl)].

The biogenesis of C19- and C21-steroids has been studied in tissue slices of a paraganglioma, of a pheochromocytoma and of human adrenal cortex using radioactive steroids. Slices of paraganglioma as well as of pheochromocytoma metabolise 17-hydroxyprogesterone to cortisone, cortisol, 11-deoxycortisol and testosterone. The rate of formation of these steroids, however, by the two tumours is 8--15 times less than that in normal adrenal cortex tissue. After incubation of dehydroepiandrosterone with tissue slices of paraganglioma and pheochromocytoma, 7alpha-hydroxydehydroepiandrosterone, 11beta-hydroxy-4-androstene-3,17-dione and 4-androstene-3,17-dione were found as metabolites; testosterone was converted by both tissues to 4-androstene-3,17-dione. 17-Hydroxypregnenolone was converted to a small extent (1.7%) to dehydroepiandrosterone by slices of paranganglioma. These results show that enzymes of steroid biosynthesis (hydroxylases, oxidoreductases, delta4(-5)-isomerases, C17(-20)-desmolases) are present in both paraganglioma and pheochromocytoma.

Adrenal Cortex↗
PubMed1978

Comparative studies on the radioimmunological determination of carcinoembryonic antigen in tumour tissue.

Human carcinoembryonic antigen (CEA) was measured in perchloric acid extracts from 9 malignant gastrointestinal tumours, using two different radioimmunological methods (Hoffmann-La Roche and CEA-IRE-SORIN). When standard curves were set up, quantitative differences in the degree of inhibition were found between the standards from the two manufacturers. In the Hoffmann-La Roche assay the CEA binding curves of all tumour extracts ran parallel with the standard. However, when the CEA-IRE-SORIN assay was applied two of the nine tumours exhibited different slopes. In one case, using the CEA-IRE-SORIN method, various parts of the tumour exhibited binding curves with non-parallel slopes. The present results suggest that radioimmunologically heterogeneous CEA occurs in different gastrointestinal tumours as well as in various parts of the same tumour.

Carcinoembryonic Antigen↗
PubMed1978

Diastereomeric 7-ureidoacetyl cephalosporins. I. Superiority of 7alpha-H-L-isomers over D-isomers.

The synthesis and in vitro structure-activity relationship of 7-ureidoacetyl cephalosporins carrying various substituents in the 3-position, compounds that showed an enhanced broad spectrum of antibacterial activity, has been outlined. Contrary to most of the previous observations with diastereomeric isomers of cephalosporins, it has been found that the L-side chain isomers also are very potent antibiotics and are even more active inhibitors of certain beta-lactamase-producing Gram-negative bacteria than the corresponding D-side chain isomers. SQ 69,613, 7beta-[[L-[(aminocarbonyl)amino]-2-furanylacetyl]amino]-3-[[(1-methyl-1H-tetrazol-5-yl) thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, sodium salt, the most active compound tested, except for activity against staphylococci, was as active in vitro as cefamandole.

Amino Acids↗
PubMed1978

Diastereomeric 7-ureidoacetyl cephalosporins. II. 7beta [[[(Aminocarbonyl) amino]-2-thienylacetyl] amino]-7-methoxy-3-[[(1-methyl-1H-tetrazol-5-yl) thio] methyl]-8-oxo-5-thia-1-azabicyclo [4.2.0] oct-2-ene-2-carboxylic acid.

The synthesis and antibacterial activity in vitro of 7-methoxylated cephalosporins having a thienylureidoacetyl or a thienylglycyl C-7 side-chain are described. Acylation of 7 beta-amino-7-methoxycephems with a novel 2-aminooxazolone hydrochloride under neutral conditions gave the thienylureidoacetyl derivatives in good yield with retention of configuration. 7 beta-[[D-[(Aminocarbonyl)amino]-2-thienylacetyl]amino]-7-methoxy-3-[[(1-methyl-1H-tetrazol-5-yl)thio] methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid sodium salt (SQ 14,359) was found to have a broad-spectrum of antibacterial activity in vitro, particularly against beta-lactamase-producing organisms.

Bacteria↗
PubMed1978

Studies on the metabolism of steroid hormones in a virilizing adrenal cortex adenoma.

Slices of an adreno-cortical adenoma which had been obtained at operation from an 11-year-old girl with clinical signs of virilism were incubated with each of the following steroids: [1,2-3H]progesterone, [4-14C]pregnenolone, [1,2-3H]testosterone, [4-14C]androstenedione and [7-3H]dehydroepiandrosterone, respectively. Isolation and identification of the free radioactive metabolites were achieved by gel column chromatography on Sephadex LH-20, thin-layer chromatography, radio gas chromatography and isotope dilution. After incubation of progesterone, the following metabolites were identified: 11beta-hydroxyprogesterone, 16alpha-hydroxyprogesterone, 17alpha-hydroxyprogesterone, 21-deoxycortisol, corticosterone and cortisol. Pregnenolone was metabolized to 17alpha-hydroxypregnenolone, progesterone, dehydroepiandrosterone, androstenedione and 11beta-hydroxyandrostenedione. When testosterone was used as substrate, 11beta-hydroxytestosterone, androstenedione and 11beta-hydroxyandrostenedione were found as metabolites, whereas androstenedione was metabolized to testosterone and 11beta-hydroxyandrostenedione. After incubation of dehydroepiandrosterone, only androstenedione and 11beta-hydroxyandrostenedione were isolated and identified. From these results, it appears that cortisol was formed in the adenoma tissue via 21-deoxycortisol and corticosterone. Delta4-3oxo steroids of the C19-series arose exclusively from pregnenolone via 17alpha-hydroxypregnenolone and dehydroepiandrosterone, and not from progesterone and 17alpha-hydroxyprogesterone. Calculated on the amounts of metabolites formed, the highest enzyme activities were those of the 11beta-hydroxylase and the 17alpha-hydroxylase. It is interesting to note that only traces of testosterone were detected after incubation of androstenedione, whereas testosterone yielded large amounts of androstenedione.

Adenoma↗
PubMed1978

Hypoglycemic activity of amine derivatives. Preliminary observations.

Dicyclohexylamine and related amino compounds as well as some simple secondary amines with branched aliphatic substituents were found to decrease blood glucose levels of fasted, glucose-loaded, or streptozotocin-diabetic rats, and of fasted mice. Structure-activity relationships are discussed.

Amines↗