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Biomedical subjects

W Schmidt

Publications and source records attributed to W Schmidt.

At least 667 records · Page 37Linked to original sources
PubMed1981

[The influence of the polymorphism of the active substance on the properties of tablets. Part 3. Compressional behaviour of meprobamate (author's transl)].

Three polymorphic meprobamate-modifications (I, II, III) of different particle size were compressed without other ingredients on a hydraulic press under 30, 60, 120, and 240 N/mm2. The rather soft substance shows a high degree of densification and above ca. 60 N/mm2 also good consolidation properties. The void volumes of the compacts obey the equation of Kawakita and are increasing in all cases in the sequence I leads to III leads to II. The radial breaking strength generally decreases in the same succession and depends linearly on the logarithm of compaction pressure. It is noteworthy, that the modification with the highest density (I) has the highest plasticity and is also compacted most easily. Modification II which is slightly harder and has a density between modifications I and III, shows the greatest differences in the compaction behaviour, as compared to modification I. Its breaking strength is also increasing faster with compaction pressure than the other modifications.

Drug Compounding↗
PubMed1981

[Contribution to knowledge on magma reticulare (author's transl)].

The structure of the magma is being described consequently to light-microscopic tests. It consists of argyrophylic fibrils and a granular component. The granules consists of glycoproteins, proteoglycans and proteins. It has been attempted to trace the origin of muco-substances and their continuous development by means of light microscopic preparations. The formation of these substances occurs in the syncytiotrophoblast. They are discharged into the villus stroma and directed through the extraembryonic mesenchymee to the yolk sac. There they are absorbed by the outer layer of cells of the yolk sac and are passed on to the capillaries of the vasa vitellina. Thus the hypothesis is being affirmed that the yolk sac plays an important role for the feeding of the embryo and to be sure finds itself in full function during the time before the placenta-circulation. Possibly the blood-liquid of the early embryonal metabolism is being created from the liquid that finds itself within the extraembryonic coelom. In cases of a lesion of the embryo and a resulting faulty resorption of the alimentating substances does result an accumulation and an increasing augmentation within the extra-embryonic coelom. This is leading to the well known picture of an increase of the magma reticulare. Considerations concerning the definition of the term "magma reticulare" and its limitation towards the term of "extra-embryonic mesenchyme" are joined here. It is proposed to speak in normal cases of an extra-embryonic mesenchyme (Mesoderm) and to reserve the term of magma reticulare for conditions of pathological alterations.

Chorion↗
PubMed1980

Mutagenic activation of an antischistosomal drug by enteric Streptococcus sps in vitro and in vivo.

Previous studies have shown that a new antischistosomal drug, 4-isothiocyano-4'-nitro diphenylamine (CGP 4540, amoscanate), is not mutagenic in vitro, but the urines of animals treated with this drug have mutagenic activity. Mutagenicity can be eliminated by coadministration of some antibacterial agents and is not demonstrable in germ-free animals. The present study describes attempts to isolate and identify intestinal microorganisms responsible for the mutagenic activation of amoscanate. Streptococcus equinus, isolated from the intestinal tract of mice, as well as some other species of Streptococcus, were found to produce mutagenic activation of amoscanate when introduced into animals pretreated with antibacterial agents. Similarly, incubation of these strains with amoscanate in vitro resulted in the formation of a mutagenic product.

Aniline Compounds↗
PubMed1980

A high-performance dual-wavelength spectrophotometer and fluorometer.

In recent years it has become increasingly desirable to investigate the kinetic behavior of molecules in order to obtain information about their function. A relatively inexpensive high-performance dual-wavelength filter spectrophotometer and fluorometer is described employing both home-made and purchased parts. This system can be easily set up by any modestly equipped workshop.

Edible Grain↗
PubMed1980

[Genetic amniocentesis: technique and results in 1,000 first trimester amniocenteses (author's transl)].

The results of 1,000 transabdominal amniocenteses between 15 and 20 weeks gestation are reported. The method is described. The bio-chemical and cytogenetic results are reported. - Amniocentesis in the first trimester is not a routine investigation since fetal and maternal risks are associated with this procedure. The risk of abortion following amniocentesis was lowered from 6/1000 to 2/500 by improvement of the technique under ultra-sound control. The worst maternal complication observed was a septic abortion one day after amniocentesis. 96% of all cyto-genetic examinations showed normal karotypes. The largest group at risk were mothers over 35 years of age. In this group chromosome anomalies were found in 17 cases. All neural tube defects were found by determination of the alpha-fetoprotein in the amniotic fluid. 26 terminations of pregnancy for fetal indications were carried out. Two patients refused therapeutic abortions despite trisomy 21 for ethical reasons. One patient continues her pregnancy with a 47 XYZ pregnancy.

Abortion, Induced↗
PubMed1980

Serological and immunochemical studies of H-2 allospecificities on K36, a syngeneic tumour of AKR.

Expression of H-2 antigenic specificities on K36, a spontaneous leukaemia originating from AKR (H-2k) mice, was studied by serology and immunochemistry. Two ascites lines of the tumour, as well as a tissue culture adjusted and cloned tumour line, were used in these studies with similar results being obtained. K36 expresses on its cell surface D-region encoded H-2K antigens but does not express K-region encoded H-2K alloantigens. It also expresses on its cell membrane, H-2 specificities of foreign haplotypes not present on normal AKR lymphoid cells. The molecular basis of the H-2Dd specificity on K36 (H-2k) was analysed by immunoprecipitation and polyacrylamide gel electrophoresis. The specificity was shown to be present on a glycoprotein of apparent molecular weight 45,000. However, antisera against the H-2Dd private specificity (H-2.4) precipitate additional glycoprotein of 45,000D and also 70,000D. In tryptic peptide maps of the isolated 45,000D fraction precipitated by anti-H-2.4 serum from radiolabelled K36 glycoprotein, all H-2Dd specific peptides were present in the same quantitative ratio. This is consistent with the structural identity of the foreign H-2Dd from the K36 tumour with normal H-2Dd and supports the hypothesis of a regulator system controlling the H-2 allelism. Under certain circumstances such a system could cause suppression of one and derepression of the other H-2 gene products.

AKR murine leukemia virus↗