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Biomedical subjects

K Schubert

Publications and source records attributed to K Schubert.

At least 73 records · Page 4Linked to original sources
PubMed1983

[Interferon-inducing effect of influenza viruses following aerogenic and oral administration in NMRI mice].

The aim of our study was to investigate the interferoninducing effect of aerogenic or oral uptake of influenza viruses in animals. NMRI-mice were infected with mouse-adapted influenza viruses (A/PR/8/34, H1 N1) by aerogen and oral route. In one-day-intervals interferon titers were determined in lung lavage fluids and in lung tissues within nine days after infection. The aerogenic infection led to an increase in interferon followed by a plateau and followed by a slope. The same course of interferon given in lower values was seen in animals after oral virus uptake. The results support the idea of a stimulation of local defense mechanisms in the lung after oral antigen uptake.

Administration, Oral↗
PubMed1982

Microbial transformation of 17 alpha-cyanomethyl-17-hydroxy-4,9-estradien-3-one (STS 557) and 17 alpha-cyanomethyl-19-nortestosterone by Mycobacterium smegmatis.

Microbial transformation of the new progestagen STS 557 (17 alpha-cyanomethyl-17-hydroxy-4,9-estradien-3-one) by Mycobacterium smegmatis yielded predominantly ring A-aromatized compounds: 17 alpha-cyanomethyl-1,3,5(10),9(11)-estratetraene-3, 17-diol, 17 alpha-cyanomethyl-1,3,5(10)-estratriene-3,17-diol and the corresponding 3-methyl ethers. The analogous compound without the 9(10) double bond, 17 alpha-cyanomethyl-19-nortestosterone, was transformed mainly to 5 alpha-hydrogenated metabolites: 17 alpha-cyanomethyl-17-hydroxy-5 alpha-estran-3-one, 17 alpha-cyanomethyl-17-hydroxy-5 alpha-1-estren-3-one, 17 alpha-cyanomethyl-5 alpha-estrane-3 alpha, 17-diol, and 17 alpha-cyanomethyl-5 alpha-estrane-3 beta, 17-diol. From these results, it is concluded that 4,9-dien-3-oxo compounds are not substrates for enzymatic 5 alpha-hydrogenation.

Biotransformation↗
PubMed1981

[Chromosomal analysis of baboons and their mothers, following application to mothers of potentially post-ovulation fertility-inhibiting steroids (author's transl)].

One single does of 0.4 mg of steroid compounds Levonorgestrel (13-ethyl-17alpha-ethinyl-17beta-hydroxy-gon-4-en-3-on) or STS 557 (17alpha-cyanomethyl-17beta-hydroxy-13beta-methylgona-4.9-dien-3-on) was administered to each of six baboon mothers, right after mating. No indication whatsoever to possible mutagenic action of the compounds applied under the given experimental conditions were recordable from the bone-marrow cells of the mothers nor from the lymphocytes of peripheral blood of their newborns. Chromosomal aberrations recorded from this species were within normal limits.

Animals↗
PubMed1981

[Biotransformation of doxylamine: isolation, identification and synthesis of some metabolites (author's transl)].

After administration of therapeutic doses of doxylamine, the unchanged drug(I) and five degradation products were detected in human urine; their chemical structures are discussed and - to some extent - confirmed by synthesis. The results show that biotransformation of doxylamine in man takes place by the following routes: successive dealkylations at the nitrogen atom, giving N-demethyl-doxylamine(II) and N.N-didemethyl-doxylamine(II); cleavage at the benzhydrylether-function, resulting in the formation of 1-phenyl-1-(2-pyridyl)-ethanol(V), 1-phenyl-1-(2-pyridyl)-ethane(VI) and 1-phenyl-1-(2-pyridyl)-ethene(VII). VI and VII may be artefacts. Identification of an additional degradation product(=IV) was not possible, because the isolated quantities were too small. The analytical properties (hydrolysis!) of the pure substance and free base are thoroughly discussed, as well as the role of Chemical Ionization Mass Spectrometry with various reagent gases for the examination of biological extracts.

Biotransformation↗
PubMed1980

STS 557 as an interceptive in rodents and baboons.

Studies with mice, rats, guinea pigs and baboons were undertaken to define the interceptive action of the new progestin STS 557 (17 alpha -cyanomethyl-17 beta-hydroxy-estra-4.9(10)-diene-3-one) and to compare it with other progestins used in oral contraceptives. STS 557, norethindrone and norethindrone acetate reduced deciduoma formation as well as the number of implantations in mice and rats. Chlormadinone acetate and levonorgestrel when administered at the appropriate dose could not prevent early pregnancy or deciduoma formation. But in contrast to STS 557, levonorgestrel maintained early pregnancy in ovariectomized rats. On the other hand, STS 557 was ineffective as a postcoital agent in guinea pigs. When 0.4 mg STS 557 was orally administered to 37 female baboons 3 or 6 h after the mating period, only one pregnancy occurred in a total of 60 cycles investigated (controls: 11 pregnancies in 12 cycles investigated). The results are discussed in view of the development of an interceptive method based on STS 557.

Animals↗
PubMed1980

[Investigations for improving the microscopic detection of mycobacteria following rapid cultivation by means of a rotating incubator. I. Improvement of the fixation technique (author's transl)].

The optimal qualitative and quantitative identification by microscopy of mycobacteria cultivated in liquid medium in including several problems. Acridine-orange was used for staining in all investigations. Polyvinyl-alcohol (1--2.5%) proved to be the best means for fixing mycobacteria culture suspensions on slides. A reliable sterilization of the sides was possible with peracetic acid (3%). Tween 80 in the culture medium did not impair the adherence of the fixed suspension on the slide under these conditions. Mycobacteria in a suspension of 10(-4) mg (wet weight) per ml could be still found by microscopy with this procedure.

Acridine Orange↗
PubMed1979

Direct evidence for the involvement of prostaglandin F2 alpha in the first step of estrone-induced blastocyst implantation in the spayed rat.

The effect of prostaglandin F2 alpha (PGF2 alpha) on blastocyst implantation in spayed rats has been studied. In preliminary experiments, the first implantation sites were observed 8 - 12 hours after a single injection of estrone in ovariectomized and progesterone-conditioned rats. Intraluminal instillation of PGF2 alpha into the right uterine horn 8 - 10 h after the estrone injection increased the number of implantation sites. Even treatment with PGF2 alpha without previous estrone injection induced the first step of blastocyst implantation as shown by uterine dye site reaction (Niagara-blue test). The results are discussed with regard to the possible role of PGF2 alpha in the regulation of the blastocyst implantation processes in the rat.

Animals↗
PubMed1979

Inhibition of the 3 beta-hydroxysteroid oxidoreductase of Pseudomonas testosteroni by steroids.

55 Steroids of the estratriene and androstane type with substituents in pos. 16 alpha, 17 alpha or 17 beta were tested for inhibition of the 3beta-hydroxysteroid oxidoreductase of Pseudomonas testosteroni. Estratrien-3-ols were strong and competitive inhibitors (Ki less than 1 micron). Substituents in pos. 16 alpha of estradiol influenced the inhibitory activity distinctly. Substituents in 17 alpha- or 17 beta-position were of slight influence. 3-Methoxy estratrienes gave no inhibition of the enzymic 3 beta-OH-dehydrogenation. The 4-unsaturated 3-oxo-steroids tested were moderate inhibitors (Ki 2.4-70 micron). The activity was slightly influenced by 17 alpha-substituents. It was increased by 10 beta-substituents in the order H less than CH3 less than N3. The inhibition test can be used to select and eliminate very strong synthetic inhibitors, which are known to disturb the metabolism of steroid hormones.

3-Hydroxysteroid Dehydrogenases↗
PubMed1979

Estrogen biosynthesis and its inhibition--a review.

A short review is given about extragonadal sources of estrogens via androgen aromatization; the possible importance of this aromatization; the mechanism of aromatization, the inhibition of androgen aromatization by steroidal compounds; the importance and possible usefulness of such an inhibition.

Adult↗
PubMed1979

[Infection as indicator of finding complex environmental noxious agents within a short time (author's transl)].

We do not know whether complexes of chemical agents produce an accumulation of their respective noxious effects or whether these effects weaken each other and we have no exact methods to quantify these effects. Knowledge of such methods would be important for investigation of environmental health. In the course of researches how to influence infectious diseases by altering natural resistance we have found that it might be possible to use an indicator method: Animals exposed to such a light environmental toxic influence that they seem to be in a good health have a reduced period of survival time and an altered steroid metabolism after infection. The time of survival (after infection) and the steroid metabolism are the indicators of some hidden trouble caused by environmental influence. Here are three examples: 1) The covered intoxication with exhaust fumes, 2) the covered intoxication with lead salt and 3) the covered intoxication with DDT demonstrate the applicability of this method, results being available within a period of 2--3 weeks.

17-Ketosteroids↗
PubMed1978

[Steroid metabolism in primates. XX. Excretion of C21-steroids in urine of women and baboons (Papio hamadryas) during pregnancy].

Urinary excretion of 10 C21 steroids was investigated in women and baboons (Papio hamadryas) in various stages of pregnancy, in comparison to controls. In pregnant women, excretion of total C21 steroids is slightly increased, whereas in pregnant baboons it is slightly decreased. In women, excretion of tetrahydrocortisol and tetrahydrocortisone is diminished, that of 20 beta-OH-F (11-beta,17alpha,20beta,21-tetrahydroxy-4-pregnen-3,20-dione) and of 11-deoxycortisol is increased. In pregnant baboons no significant alterations in corticosteroid metabolism were established.

Adolescent↗
PubMed1978

[Postcoital contraception in primates. II. Examination of STS 153 and STS 287 as interceptives in the baboon (Papio hamadryas)].

The interceptive activity of 2 new synthesized steroid compounds: STS 153 (17 beta-Phenylaminocarbonyloxy-estra-1,3,5(10)-triene-3-methyl ether and STS 287 (16 alpha-Bromo-17 beta-[N',N'-dimethylhydrazino]-carbonyloxy-estra-1,3,5(10)-triene-3-methyl ether) and of 17 alpha-Ethynylestradiol was investigated in baboons.--Postcoital oral administration of 1--3 mg/kg b. w. STS 153 for 5--7 days and of 1 mg/kg b. w. STS 287 for 5 days resulted in a fertility inhibition of about 90% and 95% respectively. A dose of 2 mg/kg b. w. of ethynylestradiol was necessary to attain complete fertility inhibition. Following administration of STS 153 and STS 287, side effects were not observed. Pharmacokinetic aspects are discussed.

Animals↗
PubMed1978

[Characteristics of the ovarianc cycle in the baboon (Papio hamadryas)].

The dynamics of estradiol, estrone, 17 alpha-hydroxyprogesterone, progesterone and 20 alpha-dihydroprogesterone were investigated in the blood plasma of the pavian (papio, hamadryas) with regard to the menstrual cycle and in comparison with the human. Furthermore results were presented about the basal temperature, the fern phenomenon and the development of the sex-skin in the pavian.

Algestone↗
PubMed1978

[Postcoital contraception in primates. I. Action mechanism of a potential postovulatory fertility-inhibiting substance STS 456 in the baboon (Papio hamadryas)].

With the substance STS 456, an estrogenic active steroid, a high fertility inhibition could be obtained in the pavian, when administered p. o. over a 5 day period postcoital. The effectiveness and also the side effects were dose dependent. The antifertility mechanism is based on an luteolytic effect, demonstrated by analytical hormonal investigations. The inhibition of the synthesis of steroids in the ovary affected not only progesterone but also the estrogens.

Animals↗