Genetic analysis of the microevolutionary processes in cattle populations (the example of the B locus of blood groups)

Dynamics of allele frequencies for the B-locus of blood groups in cattle populations and of a number of phenotype indexes in these animals was studied. It is determined that natural stabilizing selection and prezygotic selection, leading to a change in genetic structure, act in every population. The role of sires' influence on this process is insignificant.     

Sampling properties of DNA sequence data in phylogenetic analysis

We inferred phylogenetic trees from individual genes and random samples of nucleotides from the mitochondrial genomes of 10 vertebrates and compared the results to those obtained by analyzing the whole genomes. Individual genes are poor samples in that they infrequently lead to the whole-genome tree. A large number of nucleotide sites is needed to exactly determine the whole-genome tree. A relatively small number of sites, however, often results in a tree close to the whole-genome tree. We found that blocks of contiguous sites were less likely to lead to the whole-genome tree than samples composed of sites drawn individually from throughout the genome. Samples of contiguous sites are not representative of the entire genome, a condition that violates a basic assumption of the bootstrap method as it is applied in phylogenetic studies.      

Effect of various amino acids and ammonium salts in a synthetic culture media on the cholera enterotoxin production

The influence of amino acids and ammonium salts on the production of cholera enterotoxin (CT) by 3 Vibrio cholerae strains of different biovars and serogroups was evaluated. As revealed in this study, toxin formation in each of the strains was quantitatively and qualitatively determined by their individual sets of amino acids. The amino acid compositions ensuring the maximum production of CT by the V. cholerae strains under study were formed. The use of ammonium salts as the only source of nitrogen in the composition of a synthetic nutrient medium for the accumulation of CT was shown to be inexpedient.     

Genetic polymorphism of transferrins in Bovinae

Variability of transferrins in Bovinae is controlled by two loci: Tf (the locus of structural transferrin gene) and T (the locus of a gene responsible for protein modification). Originally, the ancestors of Bovinae, like the other ruminants, had the R type of transferrin (T-/T- genotype, inactive T gene). Later on, the T gene activation occurred and the B type appeared (T+/T-, T+/T+ genotypes). The subsequent evolution of Bovinae was accompanied by almost complete fixation of T+ allele. In one of the Bovinae representatives (Bos taurus L.) the frequency of T- allele remained at the level of approx 0.1. A hypothesis is proposed which explains the change of the transferrin type in Bovinae by imitation of multiple allelic forms of this protein present in Tf heterozygotes, by supplementary modificatory multiple transferrin forms arising on activation of the minor gene (T+). This process is assumed to involve the reduction of Tf locus variability. Since this hypothesis proceeds from the assumption of TF heterozygote advantage, the question is considered, whether this assumption is compatible with high polymorphism of Tf locus which significantly exceeds that for other loci.     

Some observations on the effect of Daflon (micronized purified flavonoid fraction of Rutaceae aurantiae) in bancroftian filarial lymphoedema

BACKGROUND: Morbidity management is a core component of the global programme for the elimination of lymphatic filariasis. In a double-blind clinical trial, the tolerability and efficacy of Daflon (500 mg) + DEC (25 mg) or DEC (25 mg) alone, twice daily for 90 days, was studied in 26 patients with bancroftian filarial lymphoedema. RESULTS: None of the patients in either drug group reported any adverse reaction throughout the treatment period (90 days). Haematological and biochemical parameters were within normal limits and there was no significant difference between the pre-treatment (day 0) and post-treatment (day 90) values. The group receiving Daflon showed significant reduction in oedema volume from day 90 (140.6 PlusMinus; 18.8 ml) to day 360 (71.8 PlusMinus; 20.7 ml) compared to the pre-treatment (day 0, 198.4 PlusMinus; 16.5 ml) value. This accounted for a 63.8% reduction in oedema volume by day 360 (considering the pre-treatment (day 0) as 100%). In the DEC group, the changes in oedema volume (between day 1 and day 360) were not significant when compared to the pre-treatment (day 0) value. The percentage reduction at day 360 was only 9%, which was not significant (P > 0.05). CONCLUSION: This study has shown that Daflon (500 mg, twice a day for 90 days) is both safe and efficacious in reducing oedema volume in bancroftian filarial lymphoedema. Further clinical trials are essential for strengthening the evidence base on the role of this drug in the morbidity management of lymphatic filariasis.     

Comparisons of cerebral circulation parameters in schoolchildren living in the Far East and European North

Transcranial Doppler sonography and impedansometry was used to study cerebral circulation in students aged from 7 to 17 living in the North in the "absolute discomfort" area (Magadan region. 62 degrees North, 158 degrees East, n = 167) and "discomfort" area (Arkhangelsk region, 61 degrees North, 41 degrees East, n = 52). New data were obtained about both blood flow parameters in main cerebral arteries, vessels tone and vasomotor reactivity as well as differences between these indices in children from the two northern areas. The results reveal that arterial blood flow velocity (BFV) in cerebral arteries is faster in Koryaks and Evens who are the children of the native population compared to BFV in the children born in the North whose parents represent newcomers. A tendency exists in the form of vascular tone rising in the living in the North students. This tendency is more expressed in children and adolescents from Magadan region which is distinguished from Arkhangelsk region by more severe climate. The indices that characterize individual alterations of cerebral circulation under hypoxic-cold factors as well as population peculiarities related to "polar adaptive type of metabolism" forming are discussed.     

EEG correlates of geno-phenotypical features of the brain development in children of the native and newcomers' population of the Russian North-East

Traditional and original methods of EEG analysis were used to study the brain electrical activity maturation in 156 children and adolescents from 7 to 17 years old who represented the native (Koryaks and Evenks) and newcomers' populations living in severe climatic and geographic conditions of the Russian North-East. New data revealing age-, sex- and ethnic-related features in quantitative EEG parameters are presented. Markers are obtained that characterize alterations in the structure of interaction between different EEG rhythms. The results demonstrate age-dependent transformation of this structure separated in time for both different cortical areas and different EEG frequency bands. These alterations show time lag from 2 to 3 years in children of native population compared to the newcomers. The revealed differences are assumed to reflect geno-phenotypical features of morpho-functional CNS development in children of the native and newcomers' population that depend on strong adaptation tension for extreme environmental conditions.