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Biomedical subjects

W Winter

Publications and source records attributed to W Winter.

47 records · Page 3Linked to original sources
PubMed1978

A method of mass cultivation of Toxoplasma gondii in cell culture.

Large quantities of Toxoplasma gondii were cultivated in human larynx carcinoma cells (H.Ep 2, heteroploid). Virulent Toxoplasma gondii, strain RH, which were obtained from the peritoneal exsudate of mice 2 days after infection served as inoculum. As culture medium for the cells and for growth medium, Minimum Essential Medium (MEM) supplemented by 5% foetal calf serum and 200,000 IE/1 Penicillin plus 20 mg/1 Sulmycin was used. 2--3 days after inoculation, 150--200 times the amount of the inoculated Toxoplasmas could be harvested in one or several harvests.

Cells, Cultured↗
PubMed1975

[The serum concentration of vitamin A in patients with psoriasis vulgaris after oral administration of vitamin A palmitate].

After oral application of vitamin-A-palmitate in male patients with psoriasis we hourly estimated the serum concentration of vitamin A. With rapidly elevating the maximum vitamin A level was achieved in 3-4 hrs but redescended to the initial level within 24 hrs by an exponential decrease. The curve could be fitted to the "BATEMANfunction". The velocity contents k1 and k2 were calculated but were varied individually. The constant b, the time between oral application and the commencement of resorption, was estimated at 30-60 min. The chromatographical analysis of the total vitamin A in all patients yielded a unique ratio of vitamin A-alcohol, -acetate and -palmitate for each hour.

Acetates↗
PubMed1975

[Serum picture of vitamin A in healthy persons following a vitamin A palmitate loading].

After oral consumption of 150 000 U vitamin A-palmitate the serum of eight healthy men was hourly determined for vitamin A-concentration. Rapidly ascending to a maximum within three to four hours the concentration returned exponentially to its normal fasting level after 24 hours. The curve could be adapted to the BATEMAN-function. The velocity constants k1 and k2 were equal except for one case. These results were opposite to earlier results of patients with psoriasis vulgaris.

Adult↗
PubMedDate not supplied

[Mechanics of damage and biomechanical tensile strength of the femur].

The properties of the femur are represented by the micromechanics of composites and the mechanics of damage. A consideration of the femur as a composite the Young's modul is dependent on the density. The biomechanical behavior of the femur can be simulated by a one-dimensional model of the mechanics of damage. It is shown that the maximal tolerable stress and the yield stress are not direct material properties. Material behavior is determined by a damage variable that is dependent on the current strain. The results of this investigation are in good agreement with experimental results.

Biomechanical Phenomena↗
PubMedDate not supplied

[Bone tensile strength and hydrostatic stress].

A model making use of an elastic-plastic material law and continuous damage mechanics has been developed to define the strength of trabecular bone. With the aid of this model, the differences in the behaviour of bone under tensile and compressive stresses can be simulated numerically. It is also possible to calculate the loss of strength of bone via a damage variable. The calculated results are in good agreement with stress-strain curves determined experimentally.

Biomechanical Phenomena↗
PubMedDate not supplied

Conditioned taste aversions accompanied by geophagia: evidence for the occurrence of "psychological" factors in the etiology of pica.

A conditioned taste aversion procedure was used to produce an avoidance of saccharin by rats. In the first experiment, saccharin consumption was paired with cyclophosphamide in two conditioning trials during which the animals were permitted to engage in pica. In the second experiment, saccharin consumption was paired with lithium chloride in four conditioning trials during which the animals were not allowed to engage in pica. Conditioned animals in both experiments subsequently engaged in geophagia when presented with saccharin alone. The absence of geophagia in noncontingently poisoned and "sham" injected control groups indicates that the pica was due to the acquisition of a conditioned illness during the conditioning trials. In addition to providing a demonstration of "psychological" involvement in the etiology of pica, these results indicate that visceral conditioning may accompany the formation of conditioned taste aversions. It is suggested that if there is a relationship between infantile pica and adult drug addiction, a plausible mediational mechanism is that pica-prone and addiction-prone individuals are similar in possessing a high susceptibility to visceral conditioning.

Animals↗