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Biomedical subjects

H Wilke

Publications and source records attributed to H Wilke.

At least 127 records · Page 7Linked to original sources
PubMed1982

Quantitative analysis of intramembrane particle (IMP) distribution on biomembranes after freeze-fracture preparation by a computer-based technique.

An improved method for the quantitative analysis of intramembrane particles (IMPs) on freeze-fracture faces of biomembranes is described. The analysis provides, first, the number of IMPs per 1 micrometer2, second, the coefficient of dispersion (CD) of unweighted and weighted (i.e. the finite size is taken into consideration) IMP distribution, and, third, the diameters of IMPs. Additional data for further statistical evaluation are also derived. These data make it possible to numerically describe and characterize fracture faces of a membrane in a defined physiological state. They allow for comparison of normal membranes with experimentally induced alterations of the same specimen in other experiments, and for observation of differences between normal and malignant cells. Furthermore, such an analysis provides the basis for a dynamic interpretation of biomembrane components seen on the static freeze-fracture micrographs. With this numerical analysis, descriptive terms for IMP distribution such as 'random', 'aggregated' or 'clustered', which cannot be evaluated or verified, are avoided. The method, based on the Poisson statistic which provides a means for the description of different particle density distributions, is described. The validity of the method is demonstrated on artificially generated pictures and by an analysis of erythrocyte membranes before and after spectrin depletion.

Computers↗
PubMed1981

Rapid rise in plasma glucagon induced by acute cold exposure in man and rat.

The effect of acute cold exposure on the concentration of glucagon in the blood was investigated in man and in intact and adrenalectomized rats. In man fasted overnight acute cold exposure, which caused a twofold increase in O2-consumption resulted in a rapid rise in plasma glucagon. The levels of insulin and blood glucose remained unaltered, while the concentration of serum free fatty acids and beta-hydroxybutyrate increased. In fasted intact rats acute cold exposure lead to similar effects. A close parallelism between the rise in plasma glucagon and the concentration of hepatic cycloAMP was observed. Adrenalectomy did not impair the cold induced rise in plasma glucagon and hepatic cycloAMP. It is concluded that acute cold exposure caused a rapid rise in the concentration of plasma glucagon leading to an increase in the concentration of hepatic cycloAMP, thus enhancing the rate of hepatic gluconeogenesis and ketogenesis. As these alterations were similar in the absence of glucocorticoids and medulla-derived catecholamines, it is suggested that glucagon may play a role in the metabolic adaptation to acute cold exposure.

Adult↗
PubMed1979

[Alpha-1-fetoprotein in tumour tissue (author's transl)].

Using the indirect immunoperoxidase method, alpha 1-fetoprotein (AFP) can be demonstrated in paraffin sections of tumours by light-microscopy. Among 160 tumour preparations it was demonstrated in five of six endodermal sinus tumors, 19 of 40 teratomas, the three hepatoblastomas and 9 of 16 primary liver-cell carcinomas. Among 15 rhabdomyosarcomas, 15 Wilms tumours, 15 neuroblastomas and 15 other malignant tumours only one rhabdomyosarcoma contained AFP. No AFP was demonstrated in 35 various benign tumours and various other human tissue samples. Distribution of AFP-producing cells in tumour tissue is generally focal samples. In malignant teratomas AFP was found only in areas which corresponded to an endodermal sinus tumour or an embryonic carcinoma. The practical significance of the results consists of (1) demonstration and localisation of AFP in tumour tissue; (2) aiding the differential diagnosis and classification of tumours and their metastases; and (3) recognition of pathogenetic connection between embryonic carcinoma and endodermal sinus tumour.

Carcinoma, Hepatocellular↗
PubMed1979

[Therapy of hyperlipoproteinemia. Additive effect of the lipid-lowering agent d-triiodothyronine during dietetic treatment].

Combined treatment of hyperlipidaemia with a 1000-calorie-diet and d-triiodothyronine resulted in a lowering of serum cholesterol, triglycerids and lipoproteins. Concerning cholesterol and beta-lipoproteins there was an addition of reducing effects of simultaneous dietary and drug treatment. Triglycerids are influenced by the combined treatment or by dietary treatment alone to the same extent. The levels of free fatty acids rise during combined treatment while there is no change by diet alone. These observations indicate a most successful lowering of cholesterol and beta-lipoproteins by the combined therapy, but there is an increase of free fatty acids as a metabolic side effect of d-triiodothyronine.

Diet, Reducing↗
PubMed1979

[Grading procedures for neuroblastoma (author's transl)].

Various procedures of practical significance for grading neuroblastoma are described. The comparability of the grading procedures was studied on the basis of a series of 75 cases of neuroblastoma. When the grading procedure of Hughes et al. was applied to the material collected at the Childhood Tumor Registry in Kiel, the proportions of the various grades of malignancy agreed with the data on the collection in Manchester. More than 50% of the cases of neuroblastoma were undifferentiated, corresponding to grade III. An anaplastic type of neuroblastoma is also described. When applying grading procedures, one has to take the possible variations in the histologic picture of neuroblastoma into consideration.

Brain Neoplasms↗
PubMed1977

[Frequency and distribution of risk factors in hearing loss].

In 45 patients with hearing loss we found metabolic and other "risk factors" above average. In 96% of those patients there was one "risk factor" at least. Latent (63.8%) or manifest diabetes (6.6%) was most frequent. Hyperuricemia was observed in 35.9% and hyperlipoproteinemia type IIa/IIb or IV in 24.2%. Non-metabolic risk factors (overweight, elevated blood pressure, smoking, stress) were found in 80% of the patients. It seems possible and more likely that hearing loss is caused by "risk factors" and consecutive vascular complications of the inner ear than by neurologic or orthopedic diseases. The diagnosis "hearing loss" should motivate the otologist to look for "risk factors" by interdisciplinary cooperation.

Adolescent↗
PubMed1976

[Treatment of hyperlipoproteinaemia types IIa, IIb, IV and V with a combination of clofibrate and inositol nicotinate (author's transl)].

Treatment of 14 patients over eight weeks with a combined preparation containing 250 mg clofibrate and 180 mg inositol nicotinate resulted in a decrease of serum-cholesterol level of 20% and of serum triglyceride levels of 40%. The same effect was obtained in 22 patients by clofibrate alone in double doses. There was no significant difference in effect between the two preparations. Doubling the dose of the combined preparation in ten patients did not increase the lipid-lowering effect. After the combined preparation had been stopped triglycerides rose more slowly than after stopping clofibrate alone. There was no difference with regard to the rise in the cholesterol levels. The combined preparation lowered serum lipids regardless of the type of hyperlipoproteinaemia, but the extent was less with types IIa and IIb (n =15) because of the lower initial value, than in those with types IV (n = 26) and V (n = 3).

Cholesterol↗
PubMed1976

[Aseptic necrosis of head of femur and disturbance of fat-metabolism type IIa after Fredrickson (author's transl)].

The history of aseptic necrosis of the head of femur is given. Following publication of osteonecrosis in hyperlipoproteinemia type IV after Fredrickson, now for the first time the relation between aseptic necrosis of the femoral head and the primary disturbance of fat metabolism type II is revealed. There exists a hypercholesterinemia, more exactly a hyperbeta-cholesterinemia. The subgroups type IIa and type IIb are explained. Type II is of particular importance since it produces early arteriosclerosis which demands early diagnosis, since this condition can be treated by drugs and diet. In the writers' opinion further differentiation of dys-and hyperlipidemiae in aseptic necrosis of the femoral head will enable us to define signs of disturbances of lipid metabolism. The group of "idiopathic" necroses of the femoral head will become steadily smaller. According to this basic concept the hypothesis might be put forward that this type of aseptic osteonecrosis is a late complication of a differentiated fat-metabolic disturbance.

Age Factors↗
PubMed1975

Histidine and iron supplementation in dialysis and pre-dialysis patients.

Chronic renal failure (CRF) patients treated with histidine alone did not show any effect with respect to anaemia or protein metabolism, despite a rise in serum histidine levels. Beneficial effect of iron with regards to anaemia and protein metabolism was seen in CRF patients treated with iron alone or in combination with histidine. Patients with combination therapy showed accelerated improvement of anaemia in comparison with patients treated with iron alone. In RDT patients, who underwent basic treatment with parenteral iron, histidine failed to show any effect with regards to anaemia, despite significantly lowered serum histidine levels. But under histidine treatment a significant rise of transferrin levels occurred in RDT patients, so that histidine must be considered as a limiting factor in protein metabolism in these cases. Histidine requirements of RDT patients are more than 1-2 g/day, and are higher than the requirements of patients conservatively treated.

Histidine↗