Modulating Effects of Core Oligoadenylate on the Voltage-Operated Potassium Channels in Rat Pheochromocytoma Cells

We studied modulating influences of a core oligoadenylate, 2,5-ApApA, on the voltage-operated potassium channels; the agent was injected into cloned cells of the rat pheochromocytoma PC-12. Diffusion of 2,5-ApApA from a micropipette into the cell evoked clear changes in the current-voltage relationships of the integral potassium current; when positive shifts of the membrane potential reached about +20 mV, a saturation phenomenon was observed. The dependence of the probability for open state of the voltage-operated potassium channels on the membrane potential was calculated using normalization of the potassium conductance graphs; it satisfactorily fit Boltzmann's equation. Under the influence of 2,5-ApApA, activation of the potassium channels became more strongly dependent on the voltage. Within the first minutes of the action of core oligoadenylate, the potassium conductance changed by e times at a shift of the membrane potential by 12 mV, while after a stationary level of the 2,5-ApApA effect had been attained (approximately from the 25th min), the same change in the potassium conductance needed only an 8-mV shift. We conclude that 2,5-ApApA-evoked conformation modifications in the structure of the potassium channels in the cells of rat PC-12 pheochromocytoma can result from an increase in the sensitivity of voltage sensors in the above-mentioned channels to changes in the membrane potential.     

Marriage structure of Yakut populations: Migrations

Rural and urban settlements of the Republic of Sakha (Yakutia) are characterized by intense marriage migrations: both indigenous residents of different uluses (districts) of the republic (7–30%) and migrants from outside Yakutia (7–29%) contract marriages in five administrative centers analyzed in this respect. All the populations studied are characterized by a wide geographic range of the birthplaces of persons contracted marriages there (from 14 to 24 uluses of Yakutia), without any predominant migration flow from one district to another. The proportion of homolocal marriages among indigenous ethnic groups (Evenks, Evens, and Yukagirs) is as high as 75–100%; this proportion among Yakuts varies from 26 to 68%; heterolocal marriages are more characteristic of Russian immigrants (41–95%). Positive assortative marriages among persons with the same birthplaces have been found in all populations except for Momsky ulus.     

Simulation of the distribution of spinocerebellar ataxia type 1 in Yakut populations: Description of the model

A simulation model has been developed for predicting the distribution of trinucleotide repeat expansion diseases in human populations. The interface of the software used to run this model presents the options for simulating natural reproduction of a population, with the population demographic parameters taken into account, and for simulating the appearance of a dynamic mutation in populations, transmission of the mutant gene from parents to offspring, and the effect of the phenotypic expression of the disease (the patients’ life expectancy and birthrate) on the transmission of the mutant allele in the patients’ families and its accumulation in the population.     

Population genetic study of differential human fertility (exemplified by habitual abortion). VI. Nonspecific risk factors for habitual abortion

The associations between variation of morphophysiological traits, biochemical and immunological loci and incidence of repeated spontaneous abortions were examined in Moscow population. Early age of menarche, great difference in wife/husband body length and the presence of rare genotypic paired combinations for 8 biochemical and 5 immunological loci have been shown to be the main nonspecific risk factors for this type of pathology. Direct estimations of relative risk are presented.     

The Effect of Environmental Processes on the Isomeric Composition of DDT-related Compounds

The pesticide p,p’-DDT (1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene) has been used in agriculture, forestry, and vector control for decades. Technical DDT, the purity commonly used for insecticidal applications, contained p,p’-DDT as well as its constitution isomer o,p’-DDT (1-chloro-2-(2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene) and several closely related compounds. To investigate the effect of environmental processes on the isomer-specific composition of DDT and its degradation products, we examined previously published and newly acquired quantitative data with regard to o,p’-/p,p’-DDX ratios in different environmental matrices. Isomeric shifts related to the depositional regime, transfer between and within compartments, and microbial transformation were clearly observed. Shifts of the positional isomer ratios potentially can serve as indictors to track the environmental fate of DDX. For an unambiguous assignment of these shifts to specific processes, further systematic studies and complementary lab experiments are necessary.     

Genetic subdivision of the Buryat population

The results of an estimation of the level of subdivision in the Buryat ethnos (obtained on the basis of data published by a number of research teams) are given. Altogether, information about 34 loci, including 25 diallelic loci and 9 STR loci, was analyzed. The results of the analysis, both for the diallelic polymorphic variants in genes predisposed to multifactorial diseases and for neutral STR markers, indicate the subdivision of the genetic structure of the different territorial groups of Buryats. The peculiarities of the ethnogenesis and heterogeneity of the settlement of Buryat tribes on the territory of residence are considered as one possible (but not the sole) explanation of the genetic heterogeneity of different territorial groups of Buryats. It is indicated that it is important to take into account information about the territorial, ethnic, and tribal affiliation of individuals (included in the studied groups) when planning studies aiming to establish a genetic component of the determination of pathological states in humans.     

Effect of individual peculiarities of emotional sphere on formation of preference of ethanol in female and male Wistar rats

Individual characteristics of animal behavior can serve a prognostic parameter of predisposition to use of alcohol. The goal of the work was to study dynamics of formation of preference of alcohol at early stages in the process of forced alcoholization in male and female rats as well as the accompanying changes in behavior parameters. For 3 months, the rats were submitted to the forced alcoholization with 10% ethanol. Each week the rats were tested in the “two-glass trial.” Individual peculiarities of all animals were evaluated prior to, after 6 weeks, and after the end of the experiment with aid of the “open field test” and “Suok-test.” Results showed that the male rats demonstrating by the end of the experiment the significantly higher level of the alcohol preference, demonstrated at the initial stages of the forced alcoholization the significantly lower preference as compared with the remaining ones. These rats also showed before alcoholization the lower levels of the motor and exploratory activities as compared with control. On the contrary, the individuals that by the end of the experiment did not differ from control by the level of the alcohol preference demonstrated prior to alcoholization in the “Suok-test” the higher anxiety level. In females there was observed a positive correlation of a decrease of the anxiety level in the process of alcoholization with a rise of ethanol consumption. Thus, in male rats, the prognostic parameter predicting formation of the abuse can serve the degree of alcohol preference at the initial stages.