Phylogenetic surveillance of viral genetic diversity and the evolving molecular epidemiology of human immunodeficiency virus type 1

With ongoing generation of viral genetic diversity and increasing levels of migration, the global human immunodeficiency virus type 1 (HIV-1) epidemic is becoming increasingly heterogeneous. In this study, we investigate the epidemiological characteristics of 5,675 HIV-1 pol gene sequences sampled from distinct infections in the United Kingdom. These sequences were phylogenetically analyzed in conjunction with 976 complete-genome and 3,201 pol gene reference sequences sampled globally and representing the broad range of HIV-1 genetic diversity, allowing us to estimate the probable geographic origins of the various strains present in the United Kingdom. A statistical analysis of phylogenetic clustering in this data set identified several independent transmission chains within the United Kingdom involving recently introduced strains and indicated that strains more commonly associated with infections acquired heterosexually in East Africa are spreading among men who have sex with men. Coalescent approaches were also used and indicated that the transmission chains that we identify originated in the late 1980s to early 1990s. Similar changes in the epidemiological structuring of HIV epidemics are likely to be taking in place in other industrialized nations with large immigrant populations. The framework implemented here takes advantage of the vast amount of routinely generated HIV-1 sequence data and can provide epidemiological insights not readily obtainable through standard surveillance methods.     

代谢组学及其应用

对代谢组学的概念、特性、发展历史做了简要介绍,综述了当前代谢组学研究中的数据采集、数据分析中采用的技术,及代谢组学在疾病诊断、药物毒性研究、植物和微生物等邻域的应用,并对代谢组学的发展作了展望。     

Mechanism of action of antimutagens. II. Relationship between the antimutagenic effect of ionol and the stage of the mitotic cycle of Crepis capillaris L.]

When a synchronous population of Crepis capillaris L. cells was used as the experimental material, the repair of spontaneous and induced aberrations by antimutagens was established to take place at the G1 stage. A definite period within this stage when the repair proceeds is discovered.     

Mechanism of action of antimutagens. I. ionol modification of aberrations induced by different factors]

The capacity of decreasing the frequency of chromosome aberrations, spontaneous and induced by ionizing radiation (gamma-rays) and alkylating compounds (ethylene imine) was established to be inherent in ionole (2,6-di-tretbutyl-4-methylphenole). Crepis capillaris was used as the experimental material. Ionole was particularly efficient with respect to aberrations induced by ethylene imine. The decrease of the frequency of spontaneous and induced aberrations did not affect their spectrum.     

The interrelation of the antimutagenic action of mannitol to its effect on cellular metabolic processes]

The mannitol influence on mutagenesis of ionizing radiation and cyclophosphate has been studied in albino mongrel rats using the methods of genetic and biochemical analysis. N correlation is determined between antimutagenic action of this preparation and a decrease of malondialdehyde content in cells and free fractions of matrix lysosomes (beta-galactosidase; N-acetyl-beta-D-glucosaminidase) and firmly membrane-structurized microsomal (glucose-6-phosphatase) enzymes, whose level increases under the influence of mutagens. It is shown that, one of the way of antimutagenic actions of mannitol is connected with mutagenesis correction at the stage of origin of mutagenic products and their transport to chromosome DNA.     

Study of the phenomenon and substantiation of the mechanism of antimutagenesis under conditions of action of sodium fluoride

Transplanted human amnion cells have been used in experiments differing in the regularity of the sodium fluoride and alpha-tocopherol action to determine a considerable antimutagenic efficiency of the mutagenic process modifier, the efficiency being dependent on the treatment variability.     

Neutralization by bioantioxidants of virus-induced mutagenesis in cultured human cells

The ability of alpha-tocopherol to neutralize mutational process caused by persistent infection (West Nile virus, strain 229) and primary infection (virus of poliomyelitis, type II) was shown in transplanted amnion and human kidney cells. Antimutagenic effect of the modificator was registered, independently of the regime and succession of applying alpha-tocopherol and inductors.