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Biomedical subjects

G Fischer

Publications and source records attributed to G Fischer.

At least 397 records · Page 22Linked to original sources
PubMed1989

Pressure of intraoesophageal varices assessed by fine needle puncture: its relation to endoscopic signs and severity of liver disease in patients with cirrhosis.

In 40 patients with cirrhosis and oesophageal varices transmural variceal pressure was assessed endoscopically by fine needle puncture and related to endoscopic signs as well as to the severity of liver disease. Transmural pressure was significantly (p less than 0.01) higher in the presence of a red colour sign (26.7 (7.8) cm H2O) than in its absence (19.1 (6.6) cm H2O). Transmural pressure, however, was not significantly related to diameter or number of varices (diameter greater than 5 mm: 23.7 (8.4), diameter less than or equal to 5 mm: 22.2 (7.9) cm H2O; number greater than 3: 23.2 (8.0), number less than or equal to 3: 22.2 (7.8) cm H2O). The Child status (Child A: 23.9 (8.0), Child B/C: 21.3 (8.1) cm H2O) and individual Child-Pugh parameters including ascites (ascites present: 23.2 (8.3) cm H2O ascites absent: 22.8 (8.1) cm H2O) were not significantly related to transmural variceal pressure. We conclude that the endoscopic visibility of a red colour sign on the varices is associated with a high transmural oesophageal variceal pressure. Our results favour the hypothesis that variceal pressure may be of major importance for the development of the red colour sign.

Ascites↗
PubMed1989

[Immunohistochemical demonstration of L- and M2-pyruvate kinase in primary renal cell carcinomas and their metastases].

Seventeen renal cell carcinomas (RCC) were classified histologically and investigated for their expression of L- and M2-pyruvate kinase (PK) immunohistochemically. Using monoclonal antibodies we were able to demonstrate L-PK within 15 RCC and two metastases (in thyroid gland and bone) after fixation with aceton and paraffin embedding. In normal renal tissue the enzyme was localized within proximal tubules selectively. No enzyme reaction of L-PK could be demonstrated in renal oncocytoma, thyroid carcinoma, and in carcinomas of renal pelvis and lung. In contrast to this the M2-PK was detectable in all tumors and metastases investigated in this study. The results presented in this paper are able to show that (1) RCC derive from the proximal renal tubules, but not the renal oncocytoma, (2) the detection of L-PK may be helpful for identification of metastases of RCC even if they are undifferentiated and (3) there is an enzyme shift from L-PK to M2-PK within tumor cells of RCC resulting in alteration of glucose utilization from energy supply to syntheses of substrates essential for tumor cells.

Carcinoma, Renal Cell↗
PubMed1989

[A comparison of the quantified determination of the echogeneity of the liver by ultrasound and the density of the liver by CT].

A defined region of the right lobe of the liver was measured by grey scale analysis based on similar presets according to a manual input of a Region of Interest (ROI). During 20 days, the livers of healthy subjects were tested by this method in order to test the reproducibility of the results. By prospective studies, the livers of 30 patients were examined by ultrasound and CT regarding the determination of the extent of their fatty liver disease. The value of the density of liver was determined in Hounsfield units (HU). Both methods lead to parameters that characterise the fatty content of the liver. Statistic analysis shows acceptable correlation of both methods. By means of grey scale analysis in ultrasound measurements it is possible to estimate the extent of the fatty content of liver.

Adult↗
PubMed1989

[Nitrate and nitrite in the urine, saliva and blood of urologic patients].

Nitrate and nitrite contents were determined in urine, saliva, and blood of 298 patients suffering from urological diseases. Crude values of nitrate and nitrite in morning urine without any correction due to density and creatinine are sufficient for epidemiological purposes. Significant correlations exist with vegetables intake and bacteriuria, but not with age, sex, disease, smoking, and medicaments. Neither nitrate nor nitrite may be considered to be general indicators of inflammatory processes in the urogenital tract. According to recent investigations nitrite formation during bacterial infections must be seen in connection with simultaneously occurring macrophage activation, as the latter one is catalyzing the formation of carcinogenic N-nitroso compounds from nitrite and secondary amines.

Escherichia coli Infections↗
PubMed1989

[Post-proline hydrolysis activities in cerebrospinal fluid].

Post-proline hydrolytic-activity exists in various tissues and body fluids of human organism. Using electrophoretic techniques, column chromatographic methods and kinetic investigations two peaks of proteolytic activity towards glycyl-prolyl-p-nitroanilide were detected in human cerebrospinal fluid. The identity of one enzyme with dipeptidylpeptidase IV (EC 3.4.14.5) must now constitute proof of this. Among 650 patients with cerebral diseases, characterised by post-proline hydrolytic activity in cerebrospinal fluid, high enzyme activity coincide with bacterial meningitis. Furthermore, all bacteria which could be isolated from cerebrospinal fluid exhibit high activities of post-proline cleaving hydrolases. Until now, the origin of the cerebrospinal post proline hydrolytic activity is not clear, although our investigations suggested, that lymphocytes, cerebral parenchyma and bacteria may be involved in the enzyme secretion.

Dipeptidyl-Peptidases and Tripeptidyl-Peptidases↗
PubMed1989

Immunomodulation by the new synthetic thiazole derivative tiprotimod. 1st communication: synthesis and structure-activity relationships.

A series of carboxyalkylthio-substituted thiazole-carboxylic acids was synthesized and examined for macrophage activation and stimulation of the DTH (delayed type of hypersensitivity)-reaction. The structure-activity relationship in this series of new immunomodulators is discussed. Broadest immunological activity was seen for [2-(3-carboxy-1-propylthio)-4-methyl-1,3-thiazole]acetic acid (tiprotimod, HBW 538) which was selected for further studies.

Animals↗
PubMed1989

[The synthesis of physics and biology].

The hypothesis of a qualitative new field permits the prediction of a new fundamental constant. With this constant a relation between c and h can be found. The new constant permits not only a system of physics but also a new transition from physics into biology.

Biology↗
PubMed1988

Characterization of Ca2+-dependent and -independent aggregation mechanisms among mouse cerebellar cells.

To gain insight into the cellular and molecular mechanisms underlying cell interactions in the early postnatal mouse cerebellum, Ca2+-dependent and -independent aggregation mechanisms were characterized using single cell suspensions under conditions that allow discrimination between the two mechanisms. When cerebellar cells were derived from newborn to 10-day-old mouse cerebellum, both mechanisms were active and showed no major change in activity during this time period. Mg2+ could not replace Ca2+ in the Ca2+-dependent mechanism. In contrast to the Ca2+-independent mechanisms, the Ca2+-dependent mechanism was inactive at low temperatures, suggesting a necessity for molecular rearrangement within the surface membrane during aggregation. Neuraminidase, chondroitinase, heparinase or hyaluronidase treatment of cells did not influence the aggregation of cells under Ca2+-dependent and -independent conditions. Chondroitin sulfate inhibited and hyaluronic acid stimulated the Ca2+-dependent mechanism, whereas chondroitin sulfate only slightly and hyaluronic acid strongly inhibited the Ca2+-independent one. Dextran sulfate slightly inhibited both mechanisms, whereas heparin and fucoidan, a complex sulfated carbohydrate, did not influence cell aggregation, while they strongly inhibited attachment of cells to laminin. The polycation poly-L-lysine slightly stimulated the Ca2+-independent mechanism, but inhibited the Ca2+-dependent one. Interestingly, chondroitin sulfate and hyaluronic acid strongly stimulated cell aggregation under conditions where both mechanisms were almost destroyed or inactive. Dextran sulfate showed only a small effect under these conditions. These observations indicate that different molecular mechanisms are active in cell-cell versus cell-extracellular matrix interactions and suggest a hitherto unknown complexity in molecular mechanisms during early postnatal cerebellar development.

Aging↗
PubMed1988

31P NMR investigations on free and enzyme bound thiamine pyrophosphate.

Pyruvate decarboxylase (PDC) contains thiamine pyrophosphate (TPP) and Mg2+ as cofactors. 31P NMR studies with PDC in the presence of added Mn2+ reveal the pyrophosphate moiety of TPP to be a nonaccessible area for the external Mn2+ and thus proving the Mg-P-complex (taking part in the binding of the coenzyme to the protein) to be a nonaccessible area for the medium. Glyoxylic acid, acting as an inhibitor of PDC by forming a noncleavable bond with the catalytic center of TPP causes a steric immobilization of the coenzyme indicated by a line broadening of the pyrophosphate moiety.

Carboxy-Lyases↗
PubMed1988

Injuries of the lateral ligaments of the ankle joint. Operative treatment and long-term results.

Between 1980 and 1984, 268 patients with recent ankle ligament ruptures were treated with primary surgical repair at the 2nd Department of Trauma Surgery, University of Vienna. The decision for immediate operative treatment was based on clinical findings as well as on a positive stress roentgenogram. Ligament ruptures were diagnosed if the talar tilt on the injured side exceeded that on the uninjured side by 5 degrees or more or if the ventral subluxability of the talus was more than 5 mm compared with the uninjured side. One hundred twenty-two patients were followed up for 2-6 years after operation; follow-up included physical examination as well as standardized and stress roentgenograms. Good results were obtained in 80% of cases, moderate results in 17%, and poor results in 3%. All of the poor results were due to persistent radiological instability and/or arthrotic joint degeneration. The incidence of infection was 1.5%.

Adolescent↗
PubMed1988

The L2/HNK-1 carbohydrate of neural cell adhesion molecules is involved in cell interactions.

We investigated whether the L2/HNK-1 carbohydrate epitope, expressed by two unusual glycolipids and several neural adhesion molecules, including L1, neural cell adhesion molecule, J1, and the myelin-associated glycoprotein, is involved in adhesion. Monoclonal L2 antibodies, the L2/HNK-1-reactive, sulfate-3-glucuronyl residue carrying glycolipids (L2 glycolipid) and a tetrasaccharide derived from the L2 glycolipid (L2 tetrasaccharide) were added to microexplant cultures of early postnatal mouse cerebellum, and cell migration and process extension were monitored. On the substrate poly-D-lysine, Fab fragments of L2 antibodies, L2 glycolipid, and L2 tetrasaccharide inhibited outgrowth of astrocytic processes and migration of cell bodies, but only L2 glycolipid and L2 tetrasaccharide reduced neurite outgrowth. On laminin, L2 antibodies, L2 glycolipid, and L2 tetrasaccharide inhibited outgrowth of astrocytic processes. Additionally, L2 glycolipid and L2 tetrasaccharide inhibited cell migration and neurite outgrowth. Several negatively charged glycolipids, lipids, and saccharides were tested for control and found to have no effect on outgrowth patterns, except for sulfatide and heparin, which modified outgrowth patterns in a similar fashion as L2 glycolipid and L2 tetrasaccharide. On astrocytes none of the tested compounds interfered with explant outgrowth. In short-term adhesion assays L2 glycolipid, sulfatide, and heparin inhibited adhesion of neural cells to laminin. L2 glycolipid and sulfatide interfered with neuron to astrocyte and astrocyte to astrocyte adhesion, but not with neuron-neuron adhesion. The most straightforward interpretation of these observations is that the L2/HNK-1 carbohydrate and the sulfated carbohydrates, sulfatide and heparin, act as ligands in cell adhesion.

Animals↗
PubMed1988

Altered growth control of rat hepatocytes after treatment with 3,4,3',4'-tetrachlorobiphenyl in vivo and in vitro.

Alterations of hepatocyte growth control by inducers of drug-metabolizing enzymes were investigated using 3,4,3',4'-tetrachlorobiphenyl (TCB) as the inducing agent. TCB was chosen as a selective 3-methylcholanthrene-type inducer and liver tumor promoter which probably exerts its biological actions through binding to the aryl hydrocarbon (Ah) receptor. In vivo treatment of rats with TCB (200 mg/kg) markedly stimulated growth of enzyme altered liver foci and [3H]-thymidine incorporation into nuclear DNA. Hepatocyte cultures from TCB-treated rats were more sensitive to exogenous growth factors such as EGF than those from untreated controls. In vitro TCB exposure of hepatocyte cultures also altered hepatocyte growth control in a dose-dependent manner and induced drug-metabolizing enzymes. TCB treatment in vivo enhanced EGF-stimulated autophosphorylation of the EGF receptor in liver plasma membranes. The results suggest that altered growth control is due to a direct effect of TCB on hepatocytes. The proposed model may be useful to elucidate a possible linkage between the functional stress imposed on hepatocytes by sustained overexpression of an adaptive program and modulation of hepatocyte growth control.

7-Alkoxycoumarin O-Dealkylase↗