Human leucocyte antigen (HLA)-B27 encompasses an increasing number of subtypes that show diverse racial/ethnic prevalence in the world. One thousand-one-hundred and seventy unrelated individuals from Mumbai, Maharashtra, Western India were typed for HLA-B27 antigen by serological methods. HLA-B27 positivity was confirmed by polymerase chain reaction using sequence specific primers. High-resolution typing using sequence specific primers for HLA-B27 alleles (B*2701 - B*2721) was carried out in 70 HLA-B27-positive individuals. The frequency of B27 ranged between 1.48 and 9.6% among the caste groups studied. HLA-B27 subtyping identified B*2702 (1.43%), B*2704 (14.29%), B*2705 (70%), B*2707 (12.86%) and B*2718 (1.43%), respectively. The findings illustrate substantial genetic variation and heterogeneity within population groups from India. Extensive subtyping in other Indian caste groups will be necessary to resolve the evolutionary implications of HLA-B27 subtypes and their relationship to disease association in the Indian context. 相似文献
The aim of this study was to determine HIV-1 V3 sequences, in vitro biological characteristics and co-receptor usage of virus isolates from Tanzania. Virus was isolated from 14 of 17 samples investigated. Four of the isolates induced syncytia in MT-2 cells and used the CXCR4 co-receptor, while the remaining 10 isolates used the CCR5 co-receptor characteristic of non-MT-2 tropic viruses. One of the four MT-2 tropic isolates also used the CCR5 and CCR3 co-receptors. Proviral DNA was detected in all 14 isolates and PCR products were subjected to DNA sequencing. Unambiguous V3 amino acid sequences were obtained from 11 amplificates. Phylogenetic analysis indicated that these sequences were divergent and clustered in HIV-1 subtypes A, C or D. Sequences from the viruses that induced syncytia in MT-2 cells presented characteristic V3 phenotype-associated amino acids. Results of co-receptor analysis are in concordance with the isolate phenotype as determined by replication and induction of syncytia in MT-2 cells. The considerable diversity illustrated by a limited number of isolates from Tanzania is in accordance with reports from other regions of Africa. 相似文献
The extent of population diversity among GB virus C (GBV-C)/hepatitis G virus (HGV) within a persistently infected individual (Iw) was investigated by sequence analysis of multiple clones generated from polymerase chain reaction (PCR)-amplified products of cDNA analogous to fragments of 5 non-coding region (5NC), envelope region 1/2 (E1/E2) and non-structural region 3 (NS3) of viral genome. Although nucleotide substitutions were more common in coding regions than in the 5NC region, there was no region corresponding to the hypervariable region of hepatitis C virus in the E1/E2 region. Transition substitution exceeded transversion by 7 to 12-fold, and 79.4% of substitutions were synonymous. This bias against substitutions producing amino acid replacements and the use of Pfu DNA polymerase with an error rate 10 times lower than the observed frequency of substitution, suggests that most substitutions were not artefactual. This data suggests that individual genomes of HGV within an infected individual may differ from each other at 0.23–0.84% nucleotide position and at 0.42–0.61% amino acid position. 相似文献
Background: Investigation of haplotype/allele frequency data of Y-STR loci in ethnically diverse populations is essential for forensic reference database construction and genetic application. However, the population genetic characteristics of the Chinese Miao minority from Guizhou Province remain uncharacterised.
Aim: To assess forensic characteristics for 23 Y-Chromosomal STR loci in Guizhou Miao and explore population genetic relationships with geographically neighbouring populations.
Subjects and methods: Twenty-three Y-Chromosomal STRs were genotyped using the Powerplex® Y23 system in 103 unrelated Chinese Miao males from Guizhou Province, southwest China. Haplotypes and forensic parameters were obtained. Population relationships of Guizhou Miao with others were revealed using AMOVA and an MDS plot.
Results: A total of 96 haplotypes were identified with overall haplotype diversity (HD) and discrimination capacity (DC) of 0.9985 and 0.9320, respectively. Genetic differentiation was observed with most of the comparison populations, prominently for Guizhou Shui.
Conclusion: The 23 Y-STR loci were highly polymorphic and discriminating in the Guizhou Miao population and could be used for forensic practice and population genetic studies. Population relationship analysis revealed Guizhou Miao had a close genetic relationship with geographically close Guizhou Gelao, as well as Han majorities derived from different regions. 相似文献
Along with sanitation and hygiene, water is a well-known driver of child undernutrition. However, a more direct role of household (HH) water access in shaping dietary diversity remains unexplored. We assessed the association between HH water access and achievement of minimum dietary diversity (MDD) among young children. We utilized nationally-representative cross-sectional data from the 2015/16 Malawi Demographic and Health Survey, which included 4727 mother–child dyads, respectively, (26.8 ± 6.8 years, range 15–49 years) and (13.9 ± 4.9 months, range 6–23 months). HH water access was categorized as (1) basic or no access, (2) intermediate, or (3) optimal. MDD was defined as feeding a child, during the previous day, at least four of the food groups defined by the World Health Organization. Only 27.7% of the children achieved MDD standards; most of the children who achieved MDD were from HHs with optimal water access (58.4%, p < 0.001). However, only 5.9% of the mother–child dyads were from HHs with optimal water access. After adjusting for covariates, children from HHs with optimal water access had higher odds of achieving MDD than those from HHs with basic or no water access (aOR = 1.74, CI = 1.24–2.46). Our results highlight the need to incorporate water-based strategies into national nutritional policies to increase dietary diversity among Malawian infants and young children. 相似文献
Despite increasing numbers of women entering anaesthesia, they remain persistently under-represented within academic anaesthesia and research. Gender discordance is seen across multiple aspects of research, including authorship, editorship, peer review, grant receipt, speaking and leading. Women are also under-represented at higher faculty ranks and in department chair positions. These inequities are further magnified for women with intersectional identities, such as those who identify as Black, indigenous and women of colour. Several barriers to participation in research have been identified to date, including a disproportionate amount of family responsibilities, a disproportionate burden of clinical service, gender bias, sexual harassment and the gender pay gap. Several strategies to improve gender equity have been proposed. Increasing access to formal mentorship of women in academic medicine is frequently cited and has been used by healthcare institutions and medical societies. Senior faculty and leaders must also be conscious of including women in sponsorship and networking opportunities. Institutions should provide support for parents of all genders, including supportive parental leave policies and flexible work models. Women should also be materially supported to attend formal educational conferences targeted for women, aimed at improving networking, peer support and professional development. Finally, leaders must display a clear intolerance for sexual harassment and discrimination to drive culture change. Peers and leaders alike, of all genders, can act as upstanders and speak up on behalf of targets of discrimination, both in the moment or after the fact. Gender inequities have persisted for far too long and can no longer be ignored. Diversifying the anaesthesia research community is essential to the future of the field. 相似文献