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Biomedical subjects

G Fuchs

Publications and source records attributed to G Fuchs.

At least 145 records · Page 8Linked to original sources
PubMed1978

[Isolated dislocation fracture of the trapezium (author's transl)].

As a very rare injury, isolated fracture, dislocation or rarely dislocation fracture of the trapezium can be connected with difficult diagnostical problems. Routine X-rays of the hand are not always sufficient, because of overlying trapezoid-contours. Special X-rays are additionally necessary. Concerning the therapy, there is a balance in conservative and surgical treatment, depending on the kind and nature of fracture and dislocation.

Adult↗
PubMed1977

Fibrinogen Marburg a new genetic variant of fibrinogen.

A new case of congenital dysfibrinogenemia has been discovered in a 20 year old woman, who suffered from a severe postpartal hemorrhage after the delivery of her first child, followed by episodes of thrombosis. Coagulation studies reveal a prolongation of thrombin time, reptilase time was immeasurable. Thromboplastin time and partial thromboplastin time were slightly prolonged. Low fibrinogen levels were obtained by techniques, which depend on the coagulation velocity following addition of thrombin, while immunological procedures gave slightly diminished values of fibrinogen. Patients's fibrinogen had a moderate inhibitory effect on the fibrin formation in normal plasma. However, inhibitors of the fibrinogen-fibrin conversion could not be detected. Coagulation factors were normal, fibriolysis as well. The cause of the coagulation disorder was found to be a defect of the fibrinogen molecule, leading to an abnormal fibrin polmerization of patient's fibrin monomers. The release of the fibrinopeptides in the paperelectrophoresis was normal. The defect of the fibrinogen molecule did not protect from thrombotic complications. The same defect could be found in the lower scale in patient's father, 4 of her 7 brothers and sisters, and her son.

Adult↗
PubMed1977

Carbon monoxide oxidation by methanogenic bacteria.

Different species of methanogenic bacteria growing on CO(2) and H(2) were shown to remove CO added to the gas phase. Rates up to 0.2 mumol of CO depleted/min per 10 ml of culture containing approximately 7 mg of cells (wet weight) were observed. Methanobacterium thermoautotrophicum was selected for further study based on its ability to grow rapidly on a completely mineral medium. This species used CO as the sole energy source by disproportionating CO to CO(2) and CH(4) according to the following equation: 4CO + 2H(2)O --> 1CH(4) + 3CO(2). However, growth was slight, and the growth rate on CO was only 1% of that observed on H(2)/CO(2). Growth only occurred with CO concentrations in the gas phase of lower than 50%. Growth on CO agrees with the finding that cell-free extracts of M. thermoautotrophicum contained both an active factor 420 (F(420))-dependent hydrogenase (7.7 mumol/min per mg of protein at 35 degrees C) and a CO-dehydrogenating enzyme (0.2 mumol/min per mg of protein at 35 degrees C) that catalyzed the reduction of F(420) with CO. The properties of the CO-dehydrogenating enzyme are described. In addition to F(420), viologen dyes were effective electron acceptors for the enzyme. The apparent K(m) for CO was higher than 1 mM. The reaction rate increased with increasing pH and displayed an inflection point at pH 6.7. The temperature dependence of the reaction rate followed the Arrhenius equation with an activation energy (DeltaHdouble dagger) of 14.1 kcal/mol (59.0 kJ/mol). The CO dehydrogenase activity was reversibly inactivated by low concentrations of cyanide (2 muM) and was very sensitive to inactivation by oxygen. Carbon monoxide dehydrogenase of M. thermoautotrophicum exhibited several characteristic properties found for the enzyme of Clostridium pasteurianum but differed mainly in that the clostridial enzyme did not utilize F(420) as the electron acceptor.

Bacteria↗
PubMed1977

Oxidoreductases involved in cell carbon synthesis of Methanobacterium thermoautotrophicum.

Cell-free extracts of Methanobacterium thermoautotrophicum were found to contain high activities of the following oxidoreductases (at 60 degrees C): pyruvate dehydrogenase (coenzyme A acetylating), 275 nmol/min per mg of protein; alpha-ketoglutarate dehydrogenase (coenzyme A acylating), 100 nmol/min per mg; fumarate reductase, 360 nmol/min per mg; malate dehydrogenase, 240 nmol/min per mg; and glyceraldehyde-3-phosphate dehydrogenase, 100 nmol/min per mg. The kinetic properties (apparent V(max) and K(M) values), pH optimum, temperature dependence of the rate, and specificity for electron acceptors/donors of the different oxidoreductases were examined. Pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase were shown to be two separate enzymes specific for factor 420 rather than for nicotinamide adenine dinucleotide (NAD), NADP, or ferredoxin as the electron acceptor. Both activities catalyzed the reduction of methyl viologen with the respective alpha-ketoacid and a coenzyme A-dependent exchange between the carboxyl group of the alpha-ketoacid and CO(2). The data indicate that the two enzymes are similar to pyruvate synthase and alpha-ketoglutarate synthase, respectively. Fumarate reductase was found in the soluble cell fraction. This enzyme activity coupled with reduced benzyl viologen as the electron donor, but reduced factor 420, NADH, or NADPH was not effective. The cells did not contain menaquinone, thus excluding this compound as the physiological electron donor for fumarate reduction. NAD was the preferred coenzyme for malate dehydrogenase, whereas NADP was preferred for glyceraldehyde-3-phosphate dehydrogenase. The organism also possessed a factor 420-dependent hydrogenase and a factor 420-linked NADP reductase. The involvement of the described oxidoreductases in cell carbon synthesis is discussed.

Anaerobiosis↗
PubMed1977

Demonstration of granulocytic proteases in plasma of patients with acute leukemia and septicemia with coagulation defects.

To show whether direct proteolysis of coagulation factors may play a role in patients with so-called consumption coagulopathy, granulocytic neutral proteases in the plasma of patients with acute myelocytic leukemia and septicemia were assayed by one- and two-dimensional Laurell electrophoresis. Complexes between serum alpha1-antitrypsin and elastase-like granulocytic protease could be demonstrated in those patients with acute myelocytic leukemia and septicemia who also had moderate or severe coagulation defects. Despite the presence of a high antiprotease potential, addition of the elastase-like enzyme to normal plasma resulted in coagulation defects in vitro comparable to those seen in the patients. These results and the ability of the elastase-like protease to destroy isolated clotting factors suggested that in certain types of coagulation factor deficiencies direct proteolysis rather than consumption of clotting factors due to disseminated intravascular coagulation may be operational.

Blood Coagulation Disorders↗
PubMed1976

[Salivary electrolytes and serum digoxin in the Assessment of digitalis intoxication (author's transl)].

Salivary electrolytes (potassium and calcium), as well as serum digoxin levels were measured in 114 patients receiving digoxin or one of its derivatives. The mean value of the product of salivary potassium (mVal/I) and calcium (mVal/i in digoxin-treated patients without signs of digitalis intoxication (group 1) was 235 +/- 137 (SD) and with digitalis intoxication (group 2) 404 +/- 161 (SD). The difference in these values was not of statistical significance. The mean serum digoxin levels were 1.38 +/- 0.6 ng/ml (SD) in group 1 and 2.97 +/- 0.7 ng/ml (SD) in group 2; this difference is highly significant (p less than 0.001). Both salivary electrolytes and serum digoxin levels were falsely elevated in 11% of group 1 patients. 50% of the cases in group 2 showed salivary electrolyte values within the range of group 1, but there was only 1 patient with a serum digoxin level of below 2 ng/ml. It can, thus, be concluded that measurement of the salivary electrolytes is a test of only limited value in the assessment of digitalis intoxication, whereas determination of the serum digoxin level is a valuable diagnostic tool.

Calcium↗
PubMed1976

[Post-heparin-lipolytic activity in acute ethanol-induced hyperlipoproteinemia (author's transl)].

Post-heparin lipolytic-activity (PHLA) was studied in 10 healthy volunteers ingesting 0.5 g of ethanol/kg body weight initially and 0.1 g/kg body weight and hour over 5 hours. This dose led to enhancement in plasma triglycerides to about 170% of the pre-ethanol values. PHLA was determined before, 15 min, 1 and 5 hours after intake of the initial dose and showed no significant changes. These findings are compared with the results of earlier investigations. It is concluded that acute ethanol induced hyperlipoproteinemia in healthy man seems to be due mainly to enhanced hepatic synthesis of triglycerides and release of very low density lipoproteins and not to decrease catabolism of triglyceride rich lipoproteins.

Adult↗
PubMed1976

[Longtime therapy of congenital factor XIII deficiency using factor XIII concentrate].

Factor XIII was determined by enzymatic and immunochemical methods in 3 patients with congenital factor XIII deficiency. Factor XIII activity measured by trans-glutaminase assay was below 1% of normal value in each of these cases. Immunelectrophoresis determination revealed the absence of the functionally active subunit A, whereas subunit S was only slightly diminished (30 to 50% of the normal value). Substitution with factor XIII concentrate caused a parallel increase of factor XIII activity and subunit A concentration. No uptake of factor XIII activity or of subunit. A by platelets could be demonstrated. Despite discontinuous substitution over a period of six years no antibody against factor XIII activity could be demonstrated in one patient with congenital factor XIII deficiency.

Antibodies↗
PubMed1976

Acute toxicity of various solvents in the mouse and rat. LD50 of ethanol, diethylacetamide, dimethylformamide, dimethylsulfoxide, glycerine, N-methylpyrrolidone, polyethylene glycol 400, 1,2-propanediol and Tween 20.

The LD50's of various solvents frequently used in toxicological work to improve the solubility of otherwise poorly soluble compounds were determined in the mouse and rat. The substances investigated were ethanol, dimethylacetamide, dimethylformamide, dimethylsulfoxide, glycerine, N-methylpyrrolidone, polyethylene glycol 400, 1,2-propanediol and Tween 20. The substances were administered under standardized conditions to groups of 10 animals (5 females, 5 males) (mice and rats) at doses that supplied at least 3 values lying between the LD16 and LD84. The median lethal dose and slope were determined with the aid of Finney's programmed probit analysis. The results are tabulated as LD50 ml/kg with 95% confidence limits. It is recommended that when using these solvents for pharmacological and toxicological investigations not more than a quarter of the LD50 should be used because otherwise there will be confusion between the deaths due to the substance being investigated and those due to the solvent.

Acetamides↗
PubMed1975

The active species of 'CO2' utilized by reduced ferredoxin:CO2 oxidoreductase from Clostridium pasteurianum.

Reduced ferredoxin:CO2 oxidoreductase (CO2 reductase) from Clostridium pasteurianum catalyzes the reduction of 'CO2' to formate with reduced ferredoxin, an isotopic exchange between 'CO2' and formate in the absence of ferredoxin, and the oxidation of formate to 'CO2' with oxidized ferredoxin. The active species of 'CO2', i.e. CO2 or HCO3 (H2CO3), utilized by the enzyme was determined. The method employed for the species identification was that of Copper et al. (1968). Both 'CO2' reduction to formate and the exchange reaction were studied. Data were obtained which are compatible with those expected if CO2 is the active species. The V and the dissociation constant Ks of the enzyme - CO2 complex in dependence of pH were determined from initial velocity studies of the exchange reaction. V was found to be only slightly affected by pH between 5.5 and 7.5. Ks was markedly dependent on pH; the constant increased with decreasing pH from 0.2 mM at pH 7.5 to 3 mM at pH 5.5.

Aldehyde Oxidoreductases↗
PubMed1975

[Breast cancer in women as a paradigm for ageing as a hidden syncarcinogenic factor].

In man the application of so-called cancerogenic factors and the latency period of a neoplasm until its manifestation includes the factor of biological ageing. There are in humans relationships between age, localisation and incidence of tumour which can retrospectively appear as syncarcinogenic factors. Using breast carcinoma in women as an example, it is shown that a carcinogenic effect cannot be demonstrated for two of the supposed carcinogenic factors, namely repeated diagnostic radiographic measures and administration of Rauwolfia-alkaloid containing drugs.

Age Factors↗
PubMed1975

Reduced ferredoxin: CO2 oxidoreductase from Clostridium pasteurianum. Effect of ligands to transition metals on the activity and the stability of the enzyme.

Reduced ferredoxin: CO2 oxidoreductase (CO2-reductase) from Clostridium pasteurianum catalyzes the reduction of CO2 to formate at the expense of reduced ferredoxin, an isotopic exchange between CO2 and formate in the absence of ferredoxin, and the oxidation of formate to CO2 with oxidized ferredoxin. The three activities were found to be equally affected by monovalent anions known to be ligands to transition metals: The enzyme was reversibly inhibited by azide (Ki = 0.004mM), cyanate (Ki = 0.3 mM), thiocyanate (Ki = 1mM), nitrite (Ki = 0.4mM), nitrate (Ki = 6mM), chlorate (Ki = 3mM), fluoride (Ki = 5mM), and by chloride, bromide, iodide (Ki greater than 5mM). There was no observable effect of pH on the inhibition constants. The enzyme was not inhibited by carbon monoxide. The enzyme was irreversibly inactivated by low concentrations (10muM) of cyanide. The rate of inactivation increased with increasing pH with an inflection point near pH 9.5. Reduced ferredoxin and formate rather than oxidized ferredoxin or CO2 protected the enzyme from inactivation by cyanide. The enzyme was protected by azide and cyanate from inactivation. In the presence of high concentrations of the monovalent anions the rate of inactivation by heat (55 degrees C), by molecular oxygen, and by cyanide was decreased by a factor of more than 100. Half maximal protection was observed at the Ki concentrations of the two reversible inhibitors. The data are interpreted to indicate that a transition metal of weak "a class" character and a disulfide are catalytically significant groups of CO2-reductase from C. pasteurianum.

Anions↗