PubMed Health⌕ Search

Biomedical subjects

M Wenzel

Publications and source records attributed to M Wenzel.

At least 163 records · Page 9Linked to original sources
PubMed1977

Temperature-dependence of the proliferation of mouse bone marrow cells cultured in H2O- and D2O-media.

In an attempto to optimize and standardize the in vitro culture conditions of mouse bone marrow cells for assaying growth regulating factors, we studied the effects of incubation at low temperatures and of a nutrient medium containing deuteriumoxide instead of water. It was found that (1) the proliferative capacity of the cells is significantly increased by pre-incubation for 1-2 h at 0 degrees C rather than at 37 degrees C, measured by both a colony-forming and a 3H-thymidine (3H-tdr) uptake assay. A similar temperature effect on the colony-forming and 3H-tdr uptake ability is apparent after pre-incubation in D2O-medium, yet significantly lower than in H2O-medium. It was concluded that the previously observed protective effects of D2O on ascites tumor cell proliferation and viability and for hemolysis of human erythrocytes is not apparent in proliferating and colony-forming mouse bone marrow cells in vitro.

Animals↗
PubMed1977

[Biochemistry of metallocenes. III. Thymus-affinity for (103Ru)-ruthenocenyl-3-phenyl-propen-1-one].

103Ru labelled 1-Ruthenocenyl-3-phenyl-propen-1-one was administered to mice introperitoneally. The organ distribution was determined in liver, spleen, lung, muscle, blood, kidney and thymus. The highest concentration was found in the thymus-up to 22% of the injected dose/g with corresponding thymus to muscle ratios of up to 364:1. The consequences for nuclear medicine are discussed.

Animals↗
PubMed1977

Biochemistry of metalocenes. I. Distribution of 59Fe or 103Ru-labeled metalocene carboxylic acid in mice.

Metalocene carboxylic acids labeled with 59Fe or 103Ru were administered to mice and the organ distributions and amounts of label excreted were determined. Both metalocenes were excreted approximately 90 times faster than the respective inorganic chlorides 59FeCl3 or 103RuCl3. The metalocenes showed an extremely high kidney-to-muscle ratio (up to 1,000). 99mTc-labeled renal agents, tested for comparison, showed lower ratios. Retention of radioactivity in blood and the presence of free iron in urine indicate that the ferrocene derivative is degraded in vivo, but the ruthenocene analog is not.

Animals↗
PubMed1977

[The estradiol and estrone esters of [103Ru]ruthenocenecarboxylic acid. Synthesis, excretion and organ distribution (author's transl)].

The synthesis of the estradiol-17beta and estrone esters of ferrocenecarboxylic acid is described. The exchange reaction of these compounds with [103Ru]RuCl3 produced the corresponging [103Ru]ruthenocene compounds. The excretion and organ distribution of these estrogen esters in mice were quite different from those of [103Ru]ruthenocenecarboxylic acid and its methyl ester. The 103Ru-labelled estrogen esters are compared to 125I or 135I-labelled derivatives with respect to possible applications.

Animals↗
PubMed1976

[The effect of orotic acid and orotic acid derivatives on the in vitro differentiation of hippocampus neurons-morphometric and electron microscopic studies of ribosomes].

1. By means of electron microscopic and quantitative methods at the explantate cultures of the fetal hippocampus in vitro the influence of the orotic acid, sodium orotate and methylglucamine orotate on the neurogenesis was investigated. 2. After three days of the in vitro cultivation the neuroblasts influenced by these drugs show a smaller respectively not different degree of differentiation compared to the controls. 3. Under the influence of the orotic acid and of its derivatives the neurogenesis is significantly stimulated. The drugs produce a significant increase of the membrane-bound ribosomes and polysomes. The total number of ribosomes increases following the application of orotic acid by 20%, of sodium-orotate by 48% and of methylglucamine-orotate by 23% compared to the controls (alpha = 0,1%). 4. Sodium-orotate shows with reference to the neuronal development the clearest stimulatory effect. After 20 days in vitro the total number of ribosomes is by 60% higher at the treated cultures than in the controls. 5. The results might suggest, that an enlarged supply of the pyrimidine nucleotide via a raising of the RNA- and the protein synthesis might stimulate the development of the neuroblasts even under the in vitro conditions.

Animals↗
PubMed1976

[Protection of erythrocytes in D2O against damage by hyperthermy and freezing (author's transl)].

The haemolysis of erythrocytes after heating to 55 degrees C, after freezing and after osmotic damage was studied in normal water and in heavy water (D2O). Haemolysis in all cases was lower in the presence of D2O. The greatest increase in stability was observed between 5--20% D2O. The practical consequences of this protective effect for the preservation of blood are discussed.

Blood Preservation↗
PubMed1975

[Increased estradiol-estrone quotient in rat liver by hydroxysteroids: an effect of the specific hydrogen transfer between steroids].

After addition of estrone to rat liver slices, a quotient of estradiol/estrone of ca. 0.1 is reached within 1 - 2 min. By additional application of 17 beta-hydroxysteroids this quotient is changed in the direction of estradiol, although the applied concentrations of both steroids are far below the concentration of the cytoplasmic redox couple NADH/NAD. Of all the steroids tested, testosterone had the strongest influence on the quotient, especially in the liver of female rats. This influence is smaller in the livers of male rats and infantile animals. The changing of the E2/E1 quotient by testosterone can be inhibited by the antiandrogen cyproteron acetate. Steroids with hydroxy groups at C-3 or C-20 or high concentrations of non-steroids, which can be oxidized by NAD, change the E2/E1 quotient only minimally. The experiments demonstrate that in liver, the redox couple estradiol/estrone is not in equilibrium with the main redox couple of the cytoplasmic NADH/NAD. Only on account of this fact it is possible that relatively low concentrations of testosterone change the E2/E1 quotient via the C-17 leads to C-17 hydrogen transfer between steroids. Biological consequences are discussed.

Animals↗