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H Breuer

Publications and source records attributed to H Breuer.

At least 163 records · Page 9Linked to original sources
PubMed1976

[Definition and differential diagnosis of chromophobe pituitary adenomas: light and electron microscopic studies].

INTRODUCTION: Chromophobe adenomas have been defined by the absence of secretory granules in them. But this definition has become doubtful since a granulation could be electron microscopically demonstrated. Hence we studied a collection of more than 100 surgically removed pituitary adenomas in order to find precise morphological criteria for the differential diagnosis of chromophobe adenomas, specially from the sparsely granulated chromophilic tumors. Furthermore we tried to find relations between the amount and type of granulation of the tumor cells and the clinical endocrine hyperfunction. MATERIAL AND METHODS: 108 unselected pituitary tumors were studied by light and electron microscopic methods. For histology the tissue was fixed in Helly's fluid or in buffered formalin. The paraffin wax sections were stained with haematoxylin-eosin, PAS, gallocyanin-chrome alum, carmoisine L-orange G-wool green, Herlant's tetrachrome method, and performic acid-alcian blue-PAS-orange G. For electron microscopy small pieces of the tumor were fixed in buffered glutaraldehyde, postfixed in osmium tetroxide, and embedded in epon 812. Sections were stained with toluidine blue for light microscopy. Thin sections were stained with uranyl acetate and lead citrate. Electron microscopical pictures with a primary magnification of 4000 were semi-quantitatively judged for the content and the extent of rough endoplasmic reticulum, Golgi complexes, secretory granules, lysosomes, and mitochondria by a grading with 6 degrees. Results. With special stains and the electron microscope 46 adenomas could be identified which consisted only of slightly granulated or agranular cells but not of densely granulated cells. These were defined as chromophobe adenomas. Oncocytic adenomas were regarded as another tumor type and were not included. One half of the chromophobe adenomas showed ultrastructurally well developed protein-synthesizing organellas. The diameter of the secretory granules amounts up to 500 mum. One quarter had many autolysosomes or lipid droplets. On the other hand, 18 adenomas of our collection exhibited moderate acidophilic granulation with only a few denser or fully granulated cells. These were designated as sparsely granulated acidophilic adenomas. They were rich in organelles. 89% of them showed a well developed rough endoplasmic reticulum and large Golgi complexes as signs of high endocrine activity. The secretory granules had diameters between 200 and 600 upsilonm. The autolysosomes were for the most part small and rare. The 20 fully granulated acidophilic adenomas could be easily recognized and are not discussed in this paper. The sparsely granulated mucoid cell-adenomas were easily identified by a positive PAS-reaction. DISCUSSION: From our studies we conclude that chromophobe adenomas exhibit only sparse granulation and no denser or fully granulated tumor cell...

Adenoma↗
PubMed1976

Uptake of cortisol by isolated rat liver cells. A phenomenon indicative of carrier-mediation and simple diffusion.

The uptake of cortisol by isolated rat liver cells was studied. Cortisol was taken up rapidly; the uptake increased with increasing temperature and reached a plateau after 45 s at 37 degrees, C, after 60 s at 27 degrees C, and after 90 s at 22 degrees C; at 5 degrees C the uptake increased linearly with time. The uptake was linear up to 1.5 mg of cell protein. Analysis of uptake as a function of increasing concentration of cortisol in the external medium indicated the presence of two saturable systems: a high-affinity system with an apparent Km value of 190 +/- 25 nM and a low-affinity system with an apparent Km value of 2200 +/- 180 nM. Above 600 nM, the rate of uptake of cortisol increased almost linearly with increasing cortisol concentration. Treatment of cells with KCN or 2,4-dinitrophenol inhibited the two saturable components, leaving the nonsaturable system unaffected. The affinity constants, Ka, were 6 X 10(6) M-1 and 0.6 X 10(6) M-1 for the high and low affinity components, respectively. These values increased approximately two-fold when uptake rates were corrected for diffusion. Cortisone and corticosterone inhibited the uptake of cortisol by liver cells competitively; dexamethasone inhibited cortisol uptake noncompetitively. Similarly, oestrone, oestradiol and testosterone decreased the uptake of cortisol, at a concentration of 2000 nM in the external medium, by 20, 49 and 35 percent, respectively; the inhibition was noncompetitive. p-Chloromercuribenzoate, N-ethylmaleimide and 1-fluoro-2,4-dinitrobenzene decreased the uptake of cortisol. Ouabain did not influence the uptake of cortisol; varying the external sodium concentration also did not affect uptake of cortisol. Cyclic-3',5'-adenosine monophosphate had a stimulatory effect. The results show that the first step, before cortisol is bound to intracellular binding proteins, is the uptake of cortisol by proteins in the plasma membrane. At lower concentrations of cortisol, uptake takes place by saturable processes; at higher concentrations saturation is not achieved, indicating that simple diffusion becomes the major route of transport into the cell. The proteins in the plasma membrane probably function as carriers to transport the glucocorticoid into the cell.

Animals↗
PubMed1976

Effect of oxygen shortage on the metabolism of oestrone in the hemoglobin-free perfused rat liver.

The isolated rat liver was perfused with a haemoglobin-free, albumin containing salt solution at 28 degrees and 37 degrees C, respectively, with [4-14C]oestrone as substrate. During perfusion, the functional state of the liver was checked by continuously measuring the oxygen pressure and hydrogen ion concentration in the perfusion medium, flow rate, oxygen tension at various areas of the liver surface, and oxygen consumption; in addition, the following biochemical parameters were determined: ATP, ADP, lactate and pyruvate in liver tissue, and lactate and pyruvate in the perfusion medium. After 30 min of perfusion, free steroids, steroid glucuronides, steroid sulphates and the remaining water-soluble metabolites, present in liver tissue, perfusion medium and bile, were separated from each other and characterised by thin-layer and paper chromatography. It was found that, during perfusion at 37 degrees C, less hydroxylated metabolites were formed than at 28 degrees C. In contrast, metabolites whose formation is not directly oxygen-dependent, such as glucuronides and sulphates, arose in higher amounts at 37 degrees C than at 28 degrees C. It may be concluded that the relative shortage of oxygen at 37 degrees C leads to a selective impairment of metabolic pathways requiring a sufficient supply of molecular oxygen. Since oxidative processes play an important role in the biogenesis and metabolism of steroid hormones, it is evident that results, obtained in perfusion experiments with haemoglobin-free media at 37 degrees C, must be treated with reserve.

Animals↗
PubMed1975

Blood serotonin in schizophrenic children. A preliminary study.

Blood serotonin levels were measured in schizophrenic children, all of whom showed manifestations of illness in the first 2 years of life, and controls. Serotonin levels were higher in patients (mean = 0.267 mug/ml) than in controls (mean = 0.218 mug/ml), although the difference did not reach statistical significance. Serotonin levels were significantly higher in patients with florid psychosis and those with lower IQs than in patients in remission or partial remission or higher IQs.

Adolescent↗
PubMed1975

The effect of fluorocarbon FC 43 on the metabolism of steroids during perfusion of the isolated rat liver.

The influence of fluorocarbon FC 43 on the metabolism of oestrogens in the isolated perfused rat liver was investigated. In comparative once-through perfusions with FC 43 emulsion or albumin solution as perfusion medium, the clearance rates of oestrone and its metabolites were determined. In perfusions with FC 43, the clearance of oestrone was lower, and the metabolites formed in the liver were more concentrated in the outflowing medium than in perfusions without fluorocarbon. This can be explained by the high affinity, even of conjugated oestrogens, to FC 43, which is established by equilibrium dialysis and partition coefficient. The results presented here show that the fluorocarbon has a strong influence of its own on the metabolism of steroids in the isolated perfused liver. Therefore, this solvent should be avoided as medium when the metabolism of steroids is studied in perfusion experiments.

Albumins↗
PubMed1975

[Metabolism of retro-progesterone and 17-hydroxy-retro-progesterone].

In comparative studes, the metabolism of retro-progesterone (9 beta,10alpha-pregn-4-ene-3, 20-dinoe) and 17-hydrozy-retro-progesterone (17-hydroxy-9 beta, 10 alpha-prgn-4-ene-3, 20-dione) as well as of progesterone and 17-hydroxy progesterone was investigated. The microsomal fraction from rat tests served as enzmye preparation. Whereas progesterone was metablised to 17-hydroxy-progesterone, testosterone and androstendion, retno-progesterone did not yield the corresponding reaction products. 16 alpha-Hydroxy-retro progresterone was found to be the main metabolite of retro-progesterone and identified by gas-liquid chromatopgray/mass spectrometry. In contrast to 17-hydroxy-progesterone, no transformation of 17-hudroxy-retro-progesterone to C19-steriods was observed. From these experiments, it can beconcluded that C21 -retro-steriods are not attacked by the 17alpha-hydrozylase and the C17-C20-desmolase of mammalian origin.

Androstenedione↗
PubMed1975

[Concentrations of amino acids in the blood of different vessels of patients with cirrhosis of the liver during and after the introduction of a porto-caval anastomosis (author's transl)].

In patients with liver cirrhosis the concentrations of amino acids were measured by ion exchange chromatography in the serum of blood samples taken from various vessels during and after the performance of a porto-caval anastomosis. Statistical evaluation was carried out with a nonparametric test. In three female and eight male patients, amino acids were determined intra operationem in blood samples of the following vessels (n = number of blood samples): arm vein (n = 8), arteria femoralis (n =2), vena cava (n = 7), vena portae (n = p) and aorta abdominalis (n = 5). With exception of ornithine (aorta abdominalis versus vena cava), no statistically significant differences in the concentrations of amino acids were observed in the various blood vessels. One to three years after the introduction of the porto-caval shunt, amino acid concentrations were measured in blood from the arm vein and arteria femoralis in four female and five male patients. The concentrations of glutamic acid, phenylalanine and lysine were significantly higher in blood from the arm vein than in blood of the arteria femoralis. The concentrations of valine, leucine and isoleucine were markedly lower in patients with liver cirrhosis than in normal persons. On the basis of the present findings and of the results obtained with normal subjects, it may be concluded that porto-caval anastomosis does not exert a noticeable effect on the metabolism of amino acids in patients with liver cirrhosis.

Adult↗
PubMed1975

[Studies on the metabolism of oestrone and oestradiol-17 beta in the liver of minipigs of different ages and sexes (author's transl)].

After incubation of [4-14C]oestrone (E1) with liver slices from minipigs, the ether-soluble fraction contained [4-14C]oestradiol-17 beta (E2). In the protein-bound fractions, only polar metabolites were found, whereas in the water-soluble fraction the 3-monoglucuronide of oestriol (E1) was the preferred conjugate. When E2 was used as a substrate, E1 was present as main metabolite in the ether-soluble fraction. The radioactive metabolites in the protein-bound and water-soluble fractions were similar to those in the experiments with E1. The metabolism of E1 and E2 was dependent on age. Thus, the rate of conversion of oestrogens was greater in liver tissue of infertile male animals than in fertile males. In contrast, the two steroids were metabolised more rapidly in liver of fertile female minipigs than in infertile female animals. In fertile animals, the metabolic pattern of oestrogens in the ether-soluble, the protein-bound and the water-soluble fractions showed sex dependence: In females, E1 and E2 were metabolised to a greater extent by liver slices than in males. On the other hand, in experiments with male minipigs, E3-3-monoglucuronide was the only metabolite in the water-soluble fraction, whereas liver slices of female animals not only form E3-3-monoglucuronide, but also the 3-glucuronides of E1 and E2. The results described here show that, in liver tissue of minipigs, the oxidoreduction of E2 and E1 is the predominant reaction; in contrast to human liver, hydroxylation reactions play only a minor role. It may be concluded that there are differences in the metabolism of steroid hormones in man and minipig.

Aging↗
PubMed1975

[Studies on the metabolism of oestrone and oestradiol-17 beta in the kidneys of minipigs of different ages and sexes (author's transl)].

After incubation of [4-14C]oestrone (E1) with kidney cortex slices of minipigs, [4-14C]oestradiol-17 beta (E2) and small amounts of a polar metabolite were detected in the ether-soluble fraction. E1, E2 and polar metabolites were found in the protein-bound fraction. The water-soluble fraction contained E1-3-glucuronide (80% of total glucuronides), E2-3-glucuronide and trace amounts of the 3-monoglucuronide of oestriol (E3). When E2 was used as substrate, the main product formed was E1; it was detected in both the ether-soluble and protein-bound fractions. E1-3-Glucuronide was the main metabolite in the water-soluble fraction, which also contained some E2-3-Glucuronide. In male minipigs, the mast, the rate of conversion of E1 and E2 as well as the formation of glucuronides were significantly greater in fertile females than in infertile females. Whereas no sex difference was observed in the metabolism of oestrogens in kidneys of infertile minipigs, the rate of oxidoreduction and glucuronidation was more pronounced in fertile female animals than in the corresponding males. The present results suggest that, in the kidneys of minipigs, the ratio of E1 to E2 is shifted towards the former; furthermore, by a comparatively rapid metabolism of the oestrogenic hormone, the renal tissue contributes to the maintenance of hormonal equilibrium.

Aging↗
PubMed1975

[Radioimmunologic diagnosis and pathobiochemistry of the renin-angiotension-aldosterone system. Report of the workshop conference of the German Society for clinical chemistry on January 31 and February 1, 1975 in Bonn (author's transl)].

Studies on the individual components of the renin-angiotensin-aldosterone system are of crucial importance for the investigation of hypertension. The purpose of the workship conference was to give occasion for discussion amongst German speaking research groups on the determination of the individual components of this system, and for the consideration of new results and their pathophysiological significance, as well as possibilities for the evaluation of radioimmunological data with the aid of electronic data processing. The following report is a summary of the contributions to the discussion by those taking part in the workshop conference.

Aging↗