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Start Over Creator Brtko, J.

2. The effect of antigen atimulation on splenic transplants

Creator:
Bergmann, E. S., Leitner, W., Brtko, J., Boeckl, O., and Thalhamer, J.
Type:
article, model:article, and TEXT
Subject:
splenic autotransplantation, immunohistology, flow-cytometry, antigen stimulation, and proliferation
Language:
English
Description:
The present paper deals with the regeneration of splenic tissue after autologous transplantation. Control and transplanted rats (60 days after operation (106 cells per injection). The effect of a primary response was studied by a single injection, long-lasting bacteraemia was imitated by 5 injections in weekly intervals. Spleens and transplants were investigated by flow-cytometry and immunohistochemistry. Additionally, the proliferation activity and the specific antibody production against Escherichia coli proteins were tested. Flow-cytometric analysis showed altered behaviour of T-helper cells and B-cells in transplants following a primary response, whereas in the multiple injection group a difference between the splenic and transplant response was restricted to macrophages and MHC II+ cells. The results of the morphometric analysis revealed that the cellular composition of unstimulated transplants was very similar to that of the spleen with some subtle alterations. Only the marginal zone showed more striking differences concerning the homing of several cell classes. Under stimulatory conditions, these subtle alterations became more drastic so that CD5 + cells, B-cells and macrophages responded in an abnormal manner in both groups. The analysis of thymidine kinase disclosed decreased activity in the spleen after weekly antigen stimulation. The stimulation index of all transplant groups was significantly lower than that of the spleen. The specific antibody (IgG) production after a single immunization was highest in the transplant group. All groups responded after the multiple challenge. In conclusion, the results demonstrate that splenic transplants differs in several, but subtle aspects from normal splenic tissue. The main reason for most of these alterations may be a slightly misguided recirculation and/or homing of cells.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Thyroid hormone receptor occupancy and biological effects of 3,5,3,-L-triiodothyronine (T3) in GH4C1 rat pituitary tumour cells

Creator:
Filipčík, P., Štrbák, V., and Brtko, J.
Type:
article, model:article, and TEXT
Subject:
GH4C1 rat pituitary cell line, 3,5,3,-L-triiodothyronine, thyroid hormone receptors, receptor occupancy, and biological response
Language:
English
Description:
The GH4C1 pituitary cell line, an excellent model for a thyroid hormone action study, was used for determination of the relationship between thyroid hormone receptor occupancy and intensity of cell proliferation, prolactin (PRL) production, thyrotropin (TSH) inhibition and 3,5,3,-L-triiodothyronine (T3) receptor down-regulation. Nuclear receptor population was progressively occupied by T3 in concentrations ranging from 0.025 to 10.0 nM T3. Bmax ranged from 0.029 fmol/106 cells at the lowest T3 concentration to Bmax = 12.51 fmol/106 cells at the highest concentration. Each of the observed biological events is operative within distinct dose-response ranges in cultured GH4C1 cells. The maximal biological response (except the TSH inhibition and T3 receptor down-regulation) does not require the occupation of the whole nuclear receptor population by T3 and the intensity of none of the responses studied was directly proportional to thyroid hormone receptor occupancy.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public