The functional specificity of the cardiac pacemaker system

On the basis of the own and literature data the original conception on pacemaker system of the heart experimentally is grounded. The new classification of the specialized structure--functional formations in the heart is suggested. The functional specificity of pacemaker system is considered in the comparative-ontogenetic aspect.     

Age-related dynamics of the genetic marker distribution in an irradiated population. Haptoglobin genetic system

The age dynamics of haptoglobin (Hp) type and allele distribution was studied in 985 workers aged 35-79 years who worked in the atomic industry. These workers were exposed to chronic radiation in a wide range of doses 17-40 years ago. Along with the chi 2 test, the relative and attributive risks of elimination of Hp types and alleles were determined to obtain the qualitative characteristics of age alterations. The substantial changes in distribution of Hp types and alleles were revealed in individuals older than 60 years. These changes depended on doses of external and internal irradiation. For instance, in individuals of this age group, who received the total dose of gamma-radiation (less than 100 cGy) and or that of plutonium-239 incorporation (less than 1.48 kBq), a decrease in Hp 2-2 and Hp2 and an increase in Hp 1-1 and Hp1 was observed. However, among the individuals of similar age (older than 62 years), who received a higher total dose of external and/or internal radiation, the different Hp type distribution showed a decrease in Hp 2-1 and an increase in Hp 1-1. In the latter case, the changes with age were dose-dependent. In individuals over 60 years of age with essential hypertension or diabetes mellitus and those who had a myocardial infarction, a decrease in Hp 2-2 and Hp2 and an increase in Hp 1-1 and Hp1 were found. This explains the changes with age in individuals irradiated at lower doses. The peculiar changes with age in individuals irradiated at higher doses are possibly due to the difference in morbidity and mortality from malignancy in various Hp type carriers.     

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.