Measuring European population stratification with microarray genotype data

A proper understanding of population genetic stratification--differences in individual ancestry within a population--is crucial in attempts to find genes for complex traits through association mapping. We report on genomewide typing of approximately 10,000 single-nucleotide polymorphisms in 297 individuals, to explore population structure in Europeans of known and unknown ancestry. The results reveal the presence of several significant axes of stratification, most prominently in a northern-southeastern trend, but also along an east-west axis. We also demonstrate the selection and application of EuroAIMs (European ancestry informative markers) for ancestry estimation and correction. The Coriell Caucasian and CEPH (Centre d'Etude du Polymorphisme Humain) Utah sample panels, often used as proxies for European populations, are found to reflect different subsets of the continent's ancestry.     

The cytogenetic effect of natural mutagenesis modifiers in a human lymphocyte culture. The action of aminobenzamide during the gibberellic acid induction of chromosome aberrations

The 3-aminobenzamide sensibilization of the cytogenetic activity of gibberellic acid in the culture of human lymphocytes has been investigated. Two-three-fold increase of the chromosome aberrations induced by gibberellic acid, irrespective of the time of 3-aminobenzamide addition to the cultures (the 28th, 46th, 72th hrs of the cultivation) is shown.     

Mechanisms of resistance of Salmonella derby cells to streptomycin

Mechanisms of high streptomycin resistance (8000 micrograms/ml) in S. derby cells carrying R plasmids were studied. The cells were isolated from clinical materials. The findings showed that the streptomycin resistance determinant in the S. derby cells was localized on the plasmid. In cell-free extracts of the strains, there was detected no inactivation of aminoglycosides by phosphorylation, adenylation and acetylation of the antibiotic molecules. The plasmid elimination from the cells of S. derby K89 by ethidium bromide resulted in loosing of streptomycin resistance by the cells. This indirectly excluded the mechanism associated with modification of the ribosomes. Streptomycin resistance in the strains studied must be due to decreased permeability of the S. derby K89 cell envelopes for streptomycin.     

PatternLab for proteomics: a tool for differential shotgun proteomics

Background  

A goal of proteomics is to distinguish between states of a biological system by identifying protein expression differences. Liu et al. demonstrated a method to perform semi-relative protein quantitation in shotgun proteomics data by correlating the number of tandem mass spectra obtained for each protein, or "spectral count", with its abundance in a mixture; however, two issues have remained open: how to normalize spectral counting data and how to efficiently pinpoint differences between profiles. Moreover, Chen et al. recently showed how to increase the number of identified proteins in shotgun proteomics by analyzing samples with different MS-compatible detergents while performing proteolytic digestion. The latter introduced new challenges as seen from the data analysis perspective, since replicate readings are not acquired.     

The action of low-intensity extremely high-freguency electromagnetic radiation on growth parameters for bacteria Enterococcus hirae

It has been found that the exposure of Enterococcus hirae ATCC9790, grown under anaerobic conditions for 30 min or 1 h, to low-intensity (flux capacity 0.06 mW/sm2) coherent electromagnetic radiation (EMI) of extremely high-frequency 45 - 53 GHz), or millimeter waves causes a marked prolongation of the lag-growth phase and a decrease in their specific growth rate, the inhibitory effect increasing in the frequency range from 49 to 53 GHz. The effect enhanced as duration of expocure was encreased from 30 min to 1 h; however, further increase in exposure duration to 2 h did not cause an enhancement of the effect. It has been shown that the action of extremely high-frequency EMI on these bacteria does not depend on medium pH (pH 8.0 or pH 6.0). It is proposed that these bacteria have defensive or reparation mechanisms which compensate for the action of radiation; the occurrence of different mechanisms for pH regulation is not ruled out.     

Comparative analysis of spontaneous unit activity of the cerebellum fastigial nucleus' neurons in different periods of vibration influence

In conditions of acute experiment on white rats anaesthetized with Nembutal (40 mg/kg, interperitonially) recording and analysis of spontaneous impulse activity of the fastigial nucleus' neurons in norm and after 5, 10 and 15 days of vibration influence on the organism were carried out. Distribution of the neurons was evaluated by the dynamics of neuronal current flow and the modality of the interspike interval hystograms, as well as the statistical parameters: the average discharge frequency and the coefficient of the interspike interval variation. It is shown that more significant changes in neuronal activity of fastigial nucleus cells are formed during the first 10 days of vibration influence. On the 15th day, there was a tendency towards return to control levels of the parameters under study.     

Effect of disruption of the entopeduncular nucleus on rat behavior in simultaneous discrimination and open field tests]

The influence of unilateral destruction of n. entopeduncularis on learning and retention of simultaneous discrimination in a T-maze and adaptation in the open filed was studied in 29 adult rats. Destruction of n. entopeduncularis in rats resulted in appreciable deviations from the normal behavior during realization of earlier acquired simultaneous discrimination and slowing down of the acquisition of a new habit. Differences in behavioral activity of the lesioned animals in the maze and open field were revealed.     

Spontaneous unit activity of locus coeruleus neurons after destruction of some nuclei of the medulla oblongata

Bilateral lesions of the nuclei prepositus hypoglossi produced a more than twofold decrease in the mean frequency discharges in the neurons of the nucleus coeruleus. The number of neurons with burst activity and the number of polymodal neurons substantially increased. Lesion of the nucleus tractus solitarius resulted in an increase in the number of neurons with regular activity and certain decrease in the mean discharge frequency of coeruleus neurons. The results confirm the suggestion about a substantial role of the nucleus prepositus hypoglossi in relaying afferent effects to the activity of locus coeruleus neurons.     

The limbical mechanisms of regulations of respiratory neurons in hypoxia conditions

The structures of limbic system have great integration in vegetative reactions. In the oxygen deficiency conditions we studied influence of irritation of limbical cortex, orbitofrontal cortes, hipotalamys, septum and hippocampus (CA1 and CA3 areas) on the impulse activity of respiratory neurons. Phases of hypoxia were the model of experiment. Irritation some of this structures on normoxia and 4-5 thousand meters higher, we discover inhibiting influense on respiratory neurons; some structures irritation had activating influence. In difficult conditions of hypoxia (7.5-8 thousand meters) on the reduction of the impulse activity of neurons, stimulation induced uncharacteristic reactions. Those different reactions of irritation limbic structures have regulation sense on respitatory neurons.