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Biomedical subjects

H P Fortmeyer

Publications and source records attributed to H P Fortmeyer.

69 records · Page 4Linked to original sources
PubMed1977

[Effect of various dietary carbohydrates on supplementary cholesterol].

The effect of addition of different carbohydrates (starch, glucose, fructose) to the feed was investigated using the experimental animal. Additionally, the admixture of cholesterol and of cholesterol plus cholic acid was tested. Fructose (70% of the feed) causes a slight increase in serum triglyceride concentration and a very slight increase in triglyceride concentration in the liver. Fructose and to a lesser degree glucose cause an increase in pyruvate kinase activity in the liver. The activity of glucose-6-phosphate dehydrogenase is increased slightly following high-dosed glucose, whereas the increase is very pronounced following fuctose-rich feed. The admixture of cholesterol (with cholic acid) causes a decrease in glucose-6-phosphate dehydrogenase activity up to 70%. The activity of glutamate dehydrogenase is decreased also following cholesterol admixture. A fructose-rich diet causes a slight degree of hyperlipemia with a metabolic situation similar to a latent diabetic state. This effect is greatly intensified by the addition of cholesterol and cholic acid to the diet of the rats. Especially striking was the increase in serum-free-fatty-acid concentrations in all groups of animals. This is speculated to be a sign of insulin deficiency. The so-called "carbohydrate-induced hypertriglyceridemia" is obviously intensified within a short period by the admixture of cholesterol plus cholic acid to the experimental diet.

Animals↗
PubMed1977

Heterotransplantation of human fetal pituitaries in nude mice.

The heterotransplantation of minced human fetal pituitaries into adult thymus-aplastic nude mice is described. Development and growth of such grafts were observed in 16 of 21 recipient mice. Histological examinations of the transplants showed typical adenohypophyseal cells. Neurohypophyseal cells could never be detected. The levels of human growth hormone (hGH) varied between 0.8 and 42.0 ng/ml in the plasma of the hosts (mean value 7.2 ng/ml, by radioimmunoassay).

Animals↗
PubMed1976

[In vivo and in vitro investigations of the effect of decortilen (16-methylenprednisolone) on lecithin synthesis in the fetal lung (author's transl)].

Lecithin synthesis in fetal lungs of the rat over three-fold methylation and over choline and CDP-choline was quantitatively determined via the incorporation rate of marked metabolites. The ability of decortilen to influence both modes of synthesis was investigated. In vivo and in vitro, the glucocorticoid stimulates lecithin formation, which can be as high as 200%, only over choline and CDP-choline.

Animals↗
PubMed1975

[The importance of the carbohydrate portion in a synthetic diet].

The influence of an almost fat-free and carbohydrate-rich diet on different serum parameters was investigated in human volunteers. These studies were supplemented by animal experiments where the effects of different additions of carbohydrates were compared. In human volunteers the fat-free and carbohydrate-rich diet caused a decrease in serum cholesterol concentration. This effect was especially seen when the initial cholesterol values were elevated. Exchange of the glucose carbohydrates (consisting predominantly of oligosaccharides) by frutose or by surose was without an influence on serum concentrations of cholesterol or triglycerides. No signs of carbohydrate-induced hyperlipemia were seen in human volunteers. Only under extreme conditions (60% fructose in the diet) a moderate increase in serum triglyceride concentration was found in animal experiments. However, serum cholesterol was unaltered even under these conditions. Additionally, no significant influence on fat concentration in the liver (triglycerides or cholesterol) was seen. Only using an imbalanced diet (80% glucose or 80% fructose) a slight increase in fat content of the liver and a moderate hypertriglyceridemia were observed. The concentration of serum cholesterol remained unaltered, cholesterol concentration in the liver diminished slightly. These experimental results are considered as evidence that only the extreme situation of a food imbalance (or hypernutrition) can cause a so-called carbohydrate-induced hyperlipemia.

Adult↗
PubMedDate not supplied

Lowering of blood glucose in athymic nude mice and rats, grafted with human lung cancers.

Human tumors were transplanted into athymic nude mice. From blood samples in the final stage of their passages we observed that in some of these lines, human lung cancer lines mostly, blood glucose generally decreased with increasing size of the tumor grafts. This observation was the reason for further investigations. Eight out of 13 human lung cancer lines caused a decrease of blood glucose in grafted mice. The extent of decrease was directly correlated with the proliferation of grafts. The results raise hope that the model of human malignant tumors, xenotransplanted and passaged into athymic nude mice, could be helpful in research on IGF and related substances.

Animals↗
PubMedDate not supplied

Vitamin B6 responsive growth of human tumors.

The model of human malignant tumors, heterotransplanted and passaged into athymic nude mice, proved to be a valuable tool for nutritional oncology. It showed that several human tumors proliferate in distinct dependence on the available vitamin B6. A surplus of the vitamin causes enhancement of growth. Proliferation is retarded in cases of reduced availability. The amount of vitamin B6 available does not only depend on the dietary supply. The contribution of the intestinal flora may be considerable. Therefore the adverse effect of a diet free of vitamin B6 is distinctly increased by additional application of a vitamin antagonist such as D-penicillamine for instance. It should be emphasized that this happens even in situations in which no clinical symptoms of vitamin deficiency could be observed at all. Our experimental findings may have consequences for those human patients who are stricken with vitamin B6 responsive tumors. A shifting supply of vitamin B6 should at least be avoided. Dietary guidance and a careful use of vitamin antagonists, such as D-penicillamine for instance, may be helpful.

Animals↗