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C Timm

Publications and source records attributed to C Timm.

24 records · Page 2Linked to original sources

Studies on the antigenicity of vital allogeneic valve leaflet transplants in immunogenetically controlled strain combinations.

The use of defined inbred strains of rats enables reproducible experimentation on the antigenicity of heart valve leaflet transplantation. The inbred strains CAP, F344, and LEW were used as syngeneic, weakly allogeneic (RT-1-identical) and strongly allogeneic (RT-1-incompatible) strain combinations. After heart valve leaflet transplantation, humoral and cell-mediated immune responses were investigated. The results were: (1) Allogeneic heart valve leaflets are antigenic. (2) Just one heart valve leaflet, applied intravascularly induces sensitization of the recipient. (3) In the weakly allogeneic system, sensitization is only revealed by donor-specific skin transplants, while in the strongly allogeneic group, sensitization is demonstrated humorally as well. (4) The greater the immunogenetical difference, the sooner sensitization appears. In the strongly allogeneic system, skin transplants were rejected as "white grafts".

Animals↗

[Disease picture of dysplasia epiphysealis hemimelica].

Dysplasia epiphysealis hemimelica - an epiphyseal developmental disturbance of the skeleton - is combined with exostose-like, tumor-simulating cartilaginous hypertrophy of bone tissue, mainly located at the epiphyses of the lower extremities and at the tarsal bones. In the case of multiple involvement the unilateral type prevails (hemimele type); within the epiphyses it is mostly the medial part which is undergoing changes. Rare sites are patella, head of the hip bone, shoulder joint, carpalia, more commonly affected are talus as well as other tarsal bones, distal femoral epiphysis and proximal and distal tibial epiphysis. Histologically, dysplasia epiphysealis hemimelica is identical to cartilaginous exostosis. Bone formation is taking place by enchondral ossification (epiphyseal osteochondroma). The ratio between male and female is 3:1. As a rule, this disease becomes manifest in early childhood or adolescence by indolent swellings of the joint region, restricted movement, axis shift, sometimes by differences in the length of the legs. Therapeutic guidelines are not unanimous. On one hand, correction osteotomy is not recommended until the completion of growth, while on the other hand excision of the cartilaginous hypertrophy in early childhood (before the age of 4) is postulated. Since there are less than 100 cases described in literature, another 8 cases of this extremely rare disease are to be presented here.

Adolescent↗

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↗