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Biomedical subjects

F Schneider

Publications and source records attributed to F Schneider.

At least 325 records · Page 18Linked to original sources
PubMed1979

[Control of parturition in swine. 2. Study results of parturition synchronization in swine with the prostaglandin analog cloprostenol (I.C.I. 80.996: Estrumate)].

Premature parturition was induced in 115 of 121 sows (95%) that had been given injections of 150 microgram or 200 microgram of "Estrumate", a prostaglandin analogues, on the 112th and 113th days of gestation. The average time that elapsed between injection and parturition of those 115 animals was 27.2 +/- 7.7 hours, with no difference being observed between gilts, on the one hand, and old sows, on the other. The time of gestation of the treated animals was shortened with significance from 114.6 +/- 1.6 days for the controls to 113.2 +/- 0.4 days. The average duration of parturition proper was 3.7 +/- 2.2 hours, the average litter being 11.2 +/- 3.3 piglets. The total number of piglets born was 1,320, with stillbirths accounting for 4.17%. The average weight at birth, 1,330 +/- 210 g, and the weight at weaning did not differ from weight figures recorded from the controls. The courses of parturition and puerperium were in agreement with normal biological standards. The sows treated were tested for their blood counts close to full term and for their endometrial histomorphology after weaning, with no side effects of "Estrumate" treatment being established. The behaviours of progesterone, 17-beta oestradiol, and cortisol in serum of "Estrumate"-treated sows were investigated, and congruence was established between spontaneous and prostaglandin-induced parturitions, which was in agreement with international literature. The conclusion is that 150 micrograms of 'Estrumate", administered to swine, after the 11th day of gestation has very good labour-inducing effects and ensures normal physiological parturition and piglet development.

Animals↗
PubMed1978

Anaerobiosis and oxygen recovery: changes in cell cycle distribution of Ehrlich ascites tumor cells grown in vitro.

The cell cycle distribution of in vitro cultured Ehrlich ascites tumor (EAT) cells was analysed by pulse-cytophotometry to characterize the growth cessation observed under anaerobic conditions. DNA histograms provided evidence that in the absence of oxygen EAT cells accumulate in the G1 and early S phase of the cell cycle while in the presence of oxygen an increase in G2 was observed during 24h culture period. Cellular recovery from anaerobiosis was observed soon after transfer of the cells into fresh aerobic culture medium but occurred slowly if the cells were only resupplied with air. Cell cycle analyses as well as (14C)-thymidine incorporation suggest considerable synchronization results from the introduction of anaerobiosis.

Anaerobiosis↗
PubMed1978

[Function of arginine in enzymes].

The average arginine content of proteins is 3.9%. Its frequency among the 20 amino acids of the proteins (13th position) is far lower than would be anticipated from the fact that 6 of the 61 codons for amino acids in the genetic code are arginine codons. Possible explanations for the relatively low frequency of arginine in proteins are discussed. The chemical and physicochemical properties of arginine, which are determined by the guanido group, and the method for chemical modification of arginine residues in proteins are described. The most important function of arginine residues in enzymes seems to be the recognition, binding, and orientation of anionic substrates and cofactors. This function is illustrated by numerous examples.

Amino Acids↗
PubMed1978

[Demonstration, kinetic study and solubilization of particular adenylate cyclase from Nocardia restricta].

An adenylate cyclase (EC r.6.1.1.) was found in cell-free extracts of several Nocardia species. The enzyme from Nocardia restricta has been specially studied. It is a membrane enzyme which exhibits a strong specific activity, one hundred times greater than that of mammals. It has an optimal pH of 8.5 in Tris buffer and an absolute requirement for divalent ions, Mg++ or Mn++ (Mn++ ions are the most efficient). The kinetic properties of this adenylate cyclase are similar to those that could be expected of an allosteric enzyme having, as a substrate, the ATP-Mg++ complex and, as an activator, free Mn++ ions. Ca++ ions are activators: they set up the maximum velocity without modification of the KM. GTP is a competitive inhibitor (KI = 5.10(-5) M). Fluoride ions have no detectable effect on activity. Non-ionic detergents, Lubrol WX and Triton X 100, are inhibitors of the enzyme which has been partially solubilized by repeated freezing and thawing, following by brief ultra-sonic treatment. Catalytic sites are not modified after the solubilization, but cooperative effects between moles of substrate ATP-Mn++ are diminished: the KM becomes smaller and the sigmoidal shape of the curve v = f (ATP-Mn++) is attenuated.

Adenylyl Cyclases↗
PubMed1977

Histological investigation of aortic wall in experimental sclerosis of rabbits.

Rabbit aortic changes were investigated after different sclerogenic diets. A subintimal chondroitin sulfate layer was characterized by toluidine blue metachromatic staining at pH 1--3, CEC value expressed in MgCl2 concentration: 0.4M, hyaluronidase sensitivity. This layer becomes disorganized during plaque formation and partly disaappears. A long-lasting sclerogenic diet, as well as a diet containing several sclerogenic factors, produced an increase of frequency and extension of the media necrosis, calcification, and chondroid metaplasia of the aortic wall. In these lesions, an increase of mucopolysaccharide secretion of modified smooth muscle cells was observed.

Animals↗
PubMed1977

[A new diet for inducing early experimental atherosclerosis in rabbits].

Authors by a new combined diet consisting of cholesterol vitamin D3 and sour cream produced clinico-biochemical changes characteristic for atherosclerosis in a very short period in rabbits. This diet caused severe lipoproteinaemia, hypercholesterinaemia and microscopis and macroscopic changes in the aortic wall. Authors assume, that this diet is suitable for producin atherosclerosis in a short period.

Animals↗
PubMed1977

[Radiation therapy in syringomyelia (author's transl)].

It is tried to summarize the different opinions concerning the pathogenesis, radiobiology and techniques of irradiation in the treatment of syringomyelia. The results obtained at the Radiotherapeutic Clinic of the University of Vienna are reported. Between 1969 and 1974 a total of 25 patients with this disease were treated with doses of 500 to 1500 rd SD. In 15 patients (60%) an improvement of symptoms occurred. Long time remissions could be observed in six out of 11 patients.

Humans↗