Choice of the optimum intersection point for beam radiation axis in the planning of radiotherapy

Destructive changes in cardiomyocyte mitochondria of patients with diagnosis of alcoholic heart lesion were observed by the ultrastructural analysis of the endocardial biopsies serial sections. The appearance of mitochondria with the third additional compartment and mitochondria having two zones of different electron density not separated into the special compartments are described for the first time. The development of megamitochondria having different morphology is demonstrated. Mitochondrial origin of lipophuscin granules is suggested on the basis of the ultrastructural changes. Unusual structure of atypical mitochondria may provide new properties of these organelles this being considered by the authors as an adaptive cell and mitochondria response to the new metabolic conditions.     

The genetic sequelae for plant populations of radioactive environmental pollution in connection with the Chernobyl accident

Populations of Arabidopsis thaliana (L.) Heynh., and Pinus sylvestris L., growing within 30 km of Chernobyl and Bryansk region have been analyzed for the frequency of embryonic lethal mutations on Arabidopsis and frequency of chlorophyll mutations and chromosome aberrations by pine. On pine also have been analyzed rate of mutations at enzyme loci in endosperms of seeds. Dose dependence of the value genetic damage on level of radioactive pollution was observed.     

Inactivation of alpha-ketoglutarate dehydrogenase during oxidative decarboxylation of alpha-ketoadipic acid

alpha-Ketoglutarate dehydrogenase was inactivated irreversibly and completely during oxidation of alpha-ketoadipic acid. The inactivation was revealed both in the model system with ferricyanide and in the overall reaction catalyzed by the alpha-ketoglutarate dehydrogenase complex. Neither substrate depletion nor product accumulation induced the inactivation. The results obtained were compared with recent data on the enzyme inactivation during oxidation of alpha-ketoglutaric acid. The differences in the inactivation kinetics observed with the two substrates of the enzyme were analyzed. They seem not to reflect the different mechanisms of the inactivation, but, rather, depend on the changes in the rates of the individual stages of the process.     

The replacement of accessory T-lymphocytes by synthetic peptides during the formation of splenic hematopoietic colonies

Whether accessory T cells can be replaced by the synthetic immunomodulators thymogen (Glu-Trp) and thymohexin (Arg-Lys-Asp-Val-Tyr-Arg) was studied. The latter immunomodulator was found to show a 3-fold increase in splenic colony formation after incubation of bone marrow cells with rabbit antimouse brain serum (RAMBS). The former preparation failed to show the same action. Its effect was close to that of thymocytes. When the recipients exposed to lethal irradiation were administered the RAMBS-treated bone marrow cells and one of the peptides, it was shown that in concomitant administration, thymohexin and thymocytes lost their ability to restore colony formation by RAMBS-treated bone marrow. Thymogen did not suppress the stimulating activity of thymocytes. It is suggested that the differences observed between the tested peptides in their ability to recover colony formation were determined by their structure.