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At least 109 records · Page 6Linked to original sources
PubMed1975

Identification of dimethylnitrosoamine metabolites in vitro.

The incubation of dimethylnitrosoamine (DMNA) in the presence of rat liver microsomes leads to production of formaldehyde, formic acid, methylamine, and N-methylhydrazine. When pH 5-enzymes are added to the medium there is also the formation of N-methylhydroxylamide and N,N-dimethylhydrazine. The last compound is the only metabolite produced, to a lesser extent, by the pH 5-enzymes. Thus, the denitrosated or non-denitrosated metabolites are produced either by an oxidative dealkylation and by a reduction of DMNA, catalysed by microsomal and cellular soluble enzymes.

Animals↗
PubMed1975

Degradation of dimethylnitrosoamine catalysed by physical and chemical agents.

Decomposition of dimethylnitrosoamine (DMNA) by chemical and physical agents was further investigated. Both photoirradiation with sunlight or ultraviolet ray and reductive reactions under acid conditions (likely occurring in the stomach) led to the formation of formaldehyde, formic acid, and N-methydrazine, in addition to denitrosated compounds such as methylamine, dimethylamine, and N-methylhydroxylamine. N-Methylhydrazine was the only compound which was not detected by photoirradiation under neutral conditions. The agreement between physiochemical and metabolic degradation products and the possible biological meaning are discussed together with the problem of environmental contamination by the nitroso compound.

Dimethylnitrosamine↗
PubMed1976

Hydrogen exchange at the amide group of reduced pyridine nucleotides and the inhibition of that reaction by dehydrogenases.

Stopped flow ultraviolet spectroscopy has been used to measure the rate of hydrogen exchange with solvent at the amide group of reduced nicotinamide nucleotide coenzymes. Several mechanisms for the exchange reaction are considered in the light of the kinetic data. Complex formation between the coenzyme and any of four dehydrogenases markedly slows the rate of hydrogen exchange. Hydrogen bond formation and/or hydrophobic interactions within these complexes are thought to be the reasons for the decreased rate of exchange.

Alcohol Oxidoreductases↗
PubMedDate not supplied

[Metabolic acidosis and intravenous injections of fat emulsions (role of phospholipids. Experimental study)].

In explanation of metabolic acidosis during parenteral nutrition, the authors considered the supply of H+ ions by fat emulsion, containing phospholipids of egg or soy. During intravenous infusions of 24 grams of lecithins to two healthy subjects, they observed an increased output H+ ions in urine, about 74,05 and 75,88 mEq, and a metabolic acidosis of the plasma. The theorically forcasted supply of production was 74,6 mEq. Indeed the metabolism of phospholipids supplies phosphoric ions (PO4H3), giving H+ ions at pH 7,40. The most used fat emulsions are able to give between 37 (intralipid 10%) and 61 (lipihysan 15%) mEq of H+ ions/liter.

Acidosis↗
PubMed1975

[Endocrine cells of the gastric mucous membrane].

In order to obtain an additional information concerning a possible functional role of the main types of the endocrine cells (EC and ECL) on investigation of aspiration biopsy specimens taken from the middle third of the stomach in patients with ulcerative disease of the duodenum and chronic gastritis was carried out. Changes in morphology, distribution and number of the endocrine cells in pathology of the mucosa and in various acidity of the gastric juice were followed up. On the basis of the data obtained the conclusion is made that serotonin-producing (EC) cells seem to have nothing to do with the regulation of the activity of the fundal glands, whereas the enterochromaffin-like cells (ECL) influence the production of hydrochloric acid by pavement cells.

Chronic Disease↗
PubMed1976

[Ambulatory therapy of trichomoniasis vaginalis. Clinical trial of a new Trichomonas-active azide substance].

Report on the results of the clinical trial of a new trichomonacide in ambulatory patients in a gynaecological practice. A report is given on a new drug for the treatment of vaginal trichomoniasis, which has been tried in 87 patients of a gynaecological practice under outpatient conditions. The rate of failures was 5.7% (5 of 87 cases). The advantages over alternative preparations is to be seen in the short duration of treatment (24 hours at the most), and in the favourable tolerance in spite of high doses.

Adolescent↗
PubMed1976

[Old and new dangers of blood transfusion (author's transl)].

The predominant danger of blood transfusion, even after the discovery of the ABO and Rh systems, is the immunological risk. This led in 1940 to a regulation of blood transfusion in Germany by official guidelines which were constantly adjusted in the light of new research results. The dangers due to deterioration on storage still receive too little attention although these may be of greater danger to the patient than immunisation risk. Also the assessment of other medical problems of transfusion is insufficiently applied to clinical routine.

Ammonia↗
PubMed1977

Biosynthesis of alpha-amylase and protease by Streptomyces olivaceus 142. I. Regulation of alpha-amylase activity.

Streptomyces olivaceus 142 produces amylase in the logarithmic phase of growth of the culture. The synthesis of the enzyme is induced by maltose and starch. In the case of maltose the synthesis is induced by a contaminating compound, probably being a higher than maltose polymer of glucose. The synthesis of amylase is negatively controlled by catabolic repression. The level of the activity of the enzyme depends not only on the biosynthesis but also on it proteolytic degradation.

Amylases↗
PubMed1977

Blood group activity of human sucrase from intestinal metaplasia.

Sucrases were purified from human small intestine and from areas of intestinal metaplasia of the stomach mucosa surrounding stomach cancers. The kinetic constants and pH activity profiles of enzyme preparations from the two sources were similar. No blood group activity of sucrase was detectable in preparations from three cases of intestinal metaplasia, but preparations from two other cases showed activity like that of the small intestine. These results indicate that sucrase from areas of intestinal metaplasia has similar enzymatic properties to those of enzyme from the small intestine, but that the antigenic sugar moiety of the enzyme associated with blood group activity varies.

ABO Blood-Group System↗
PubMed1975

Histochemical observations on the occurrence of glycolytic and pentose phosphate cycle enzymes in the hepatopancreas and their possible relation to eyestalk factor(s) in the crab Scylla serrata (Forskal).

Histochemical studies were carried out on some of the glycolytic enzymes viz. phosphorylase, aldose, alpha-glycerophosphate dehydrogenase (alpha-GPDH) and lactic dehydrogenase (LDH) and a key enzyme of the pentose phosphatase cycle, glucose-6-phosphate dehydrogenase (G-6-PDH), in the hepatopancreas of Scylla serrata (Forskal). 1. Weak activities of phosphorylase and aldolase and strong-activities of alpha-GPDH and LDH were noticed mainly in the brush border of the tubules and R-cell cytoplasm. A trace activity of G-6-PDH was noticed in the brush border. 2. Bilateral eyestalk removal results in inhibition of both phosphorylase and aldolase. However, enhanced activities of alpha-GPDH and LDH were noticeable 4 h after the operation. The G-6-PDH activity remained unaltered till 24 h. 3. Injection of eyestalk extract into both intact and destalked crabs activated all the enzymes.

Animals↗
PubMed1975

[Acid-base equilibrium during physiological pregnancy].

Authors applied blood-gas analysis in 30 healthy gravid women on 3,3 occassions making out 90 cases altogether by blood samples taken from the pulp of the finger capillaries. As a control 27 healthy non-gravid women were examined for comparative analysis. In 10 cases between the 16. and 28. week the results of samples taken from the arteria femoralis and the pulp were evaluated. It has been found that in the gravidity period of the 16. and 28. week respiratory alcalosis does not appear. No metabolic changes have been found during the whole period of pregnancy. The parallel examination of blood samples taken from the arteria femoralis and the pulp have proved that it is sufficient and reliable to take blood-gas analysis on the material gained from the pulp capillary only. A special importance is attached to keeping to exact methodical prescriptions.

Acid-Base Equilibrium↗