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Biomedical subjects

D Sauer

Publications and source records attributed to D Sauer.

At least 55 records · Page 3Linked to original sources
PubMed1982

De Novo Purine Synthesis in Nitrogen-Fixing Nodules of Cowpea (Vigna unguiculata [L.] Walp.) and Soybean (Glycine max [L.] Merr.).

Partially purified, cell-free extracts from nodules of cowpea (Vigna unguiculata L. Walp. cv. Caloona) and soybean (Glycine max L. Merr. cv. Bragg) showed high rates of de novo purine nucleotide and purine base synthesis. Activity increased with rates of nitrogen fixation and ureide export during development of cowpea plants; maximum rates (equivalent to 1.2 micromoles N(2) per hour per gram fresh nodule) being similar to those of maximum nitrogen fixation (1-2 micromoles N(2) per hour per gram fresh nodule). Extracts from actively fixing nodules of a symbiosis not producing ureides, Lupinus albus L. cv. Ultra, showed rates of de novo purine synthesis 0.1% to 0.5% those of cowpea and soybean. Most (70-90%) of the activity was associated with the particulate components of the nodule, but up to 50% was released from this fraction by osmotic shock. The accumulated end products with particulate fractions were inosine monophosphate and aminoimidazole carboxamide ribonucleotide. Further metabolism to purine bases and ureides was restricted to the soluble fraction of the nodule extract. High rates of inosine monophosphate synthesis were supported by glutamine as amide donor, lower rates (10-20%) by ammonia, and negligible rates with asparagine as substrate.

Journal Article↗
PubMed1982

[Immunotherapy of burns--animal experiments].

Immunologic changes are a component of the pathophysiology of severe burns. The effect of the burn toxin can be reduced by immunologic mechanism. The antigen elimination by immunologic defense mechanism additionally to the necrectomy was discussed. A significant therapeutic effect after standardised burn in the animal mouse model showed the application of heterologous antibodies against the burn antigen and the specific immunostimulation. The antibody titre and the number of lymphocytes which bind burn toxin were investigated. The animal experimental results show the real chances of the antigen elimination by passive immunisation respectively immunostimulation. Immunosuppressive influence by therapeutic measures must be avoided.

Animals↗
PubMed1981

[Immunological and immunotherapeutic studies on the model of mice following thermic injury ].

A burn toxin, which is discussed as reason of the burn disease by Schoenenberger et al., was isolated from burned skin of mice and the immunological reactions to this antigen were evaluated in burned mice longitudinally at several intervals after the trauma. We determined the specific antibodies against the burn toxin by means of the passive hemagglutination test, the burn toxin binding cells by means of the antigen specific rosette technique and the cell-mediated immunity using the macrophage electrophoretic mobility test (MEM-test). A rise of the burn toxin-specific cells could be observed with maximum at day 4 and a cell-mediated immunity between day 11 and day 13. Antibody titre was on the background about an interval of 3 weeks. Pretreatment with burn toxin or posttraumatic i. p. application of antibodies against burn toxin from rabbits eliminated primary death of mice with lethal burns. No correlation seemed to exist between the effect of treatment with antibodies and the antibody titre in the first days following burns.

Animals↗
PubMed1981

[Immunological investigations of patients after thermic injury (author's transl)].

A burn toxin, which is important for the manifestation of clinical and septical processes during the burn disease, was isolated from burned skin of mice. Using this antigen we have studied the immunological reactions against burn toxin in 10 patients following thermic trauma. We determined the specific antibodies against the burn toxin by means of the passive hemagglutination test, the level of IgM, IgG and IgA in the serum using Mancini-immunodiffusion, the burn toxin binding cells by means of the antigen specific rosette technique and the cell-mediate immunity using the macrophage electrophoretic mobility test (MEM-test). A rise of the burn toxin-specific cells could be observed with maximum at day 4 and a second peak at day 10 and cell mediated immunity between day 10 and day 15. The titer of specific antibodies increased, most following an initial decrease, after day 6, a correlation seemed to exist between this titer and the level of immunoglobulins in the serum.

Antibody Formation↗
PubMed1978

De novo purine synthesis in avian liver. Co-purification of the enzymes and properties of the pathway.

The enzymes of the de novo purine biosynthetic pathway have been partially co-purified from pigeon liver by a method dependent upon the use of the nonionic polymer polyethylene glycol for enzyme stabilization and cofractionation. Although the enzymes did not appear to constitute a large macromolecular complex it was evident that some particular inter-relationship between them was preserved during the purification procedure. Analysis of the end products and pathway intermediates was carried out primarily by sensitive high pressure liquid chromatographic techniques. Substrate and cofactor requirements were confirmed and optimal conditions of pH, temperature, and K+ ion activation established. At phosphoribosyl pyrophosphate (PP-ribose-P) concentrations below 0.3 mM the activity of the first pathway enzyme amidophosphoribosyltransferase was rate-limiting, and the inhibition of this enzyme by AMP regulated the rate of purine ring synthesis. At higher concentrations of PP-ribose-P, aminoimidazole ribonucleotide synthetase, the fifth enzyme of the pathway became rate limiting and was subject to inhibition by added AMP. It was evident that the regulation of purine synthesis was quite complex and that AMP inhibition (perhaps reflected in a low adenylate energy charge) can be effected at different points on the purine pathway.

Amidophosphoribosyltransferase↗
PubMed1978

[Effect of infection on the immune system in burns in animal experiments].

After discussing a model of infection in mice and the possibility of active immunization against pyocyanic pseudomonas, the authors describe the effect of a lipid-protein-complex achieved from isolated burnt mouse skin on pseudomonas infection. First results showed that sublethal amounts of that complex at otherwise less pathogenic suspension of pseudomonas cause a lethality of 100 per cent. This effect can partially inhibited by application of antitoxic IgG. The lethal course was not primarily caused by the infection but by the above mentioned complex which significantly lowers the resistance against pyocyanic pseudomonas.

Animals↗