ABSTRACT
Due to its numerous environmental extremes, the Tibetan Plateau--the world's highest plateau--is one of the most challenging areas of modern human settlement. Archaeological evidence dates the earliest settlement on the plateau to the Late Paleolithic, while previous genetic studies have traced the colonization event(s) to no earlier than the Neolithic. To explore whether the genetic continuity on the plateau has an exclusively Neolithic time depth, we studied mitochondrial DNA (mtDNA) genome variation within 6 regional Tibetan populations sampled from Tibet and neighboring areas. Our results confirm that the vast majority of Tibetan matrilineal components can trace their ancestry to Epipaleolithic and Neolithic immigrants from northern China during the mid-Holocene. Significantly, we also identified an infrequent novel haplogroup, M16, that branched off directly from the Eurasian M founder type. Its nearly exclusive distribution in Tibetan populations and ancient age (>21 kya) suggest that M16 may represent the genetic relics of the Late Paleolithic inhabitants on the plateau. This partial genetic continuity between the Paleolithic inhabitants and the contemporary Tibetan populations bridges the results and inferences from archaeology, history, and genetics.
Subject(s)
Emigration and Immigration , Genome, Mitochondrial/genetics , Paleontology , Base Sequence , China , Founder Effect , Genetic Variation , History, Ancient , Humans , Molecular Sequence Data , TibetABSTRACT
BACKGROUND: Drug resistance profiles of human immunodeficiency virus-1 (HIV-1) in treatment-naïve infections have been reported in developed countries. However, little is known in developing countries, including China, especially in treatment-naïve volunteer blood donors. STUDY DESIGN AND METHODS: Fifty-two HIV-1-positive samples of blood donors were collected from 2005 to 2006 in Yunnan, China. Recent and long-term infections were distinguished by the HIV-1 subtypes B, E, and D immunoglobulin G-capture enzyme immunoassay assay. The nucleotide sequences of pol genes were amplified and sequenced. Phylogenetic tree and drug resistance analyses were performed. RESULTS: Of 49 samples successfully analyzed, circulating strains were circulating recombinant form (CRF)08_BC (51.0%), CRF07_BC (24.5%), CRF01_AE (20.4%), and B (4.1%). No protease inhibitors (PI) major drug resistance mutation (DRM) was detected. Six samples (12.2%) displayed seven minor PI DRMs. Nine samples (18.4%) displayed 10 nucleoside reverse transcriptase inhibitor DRMs, and DRMs to nonnucleoside reverse transcriptase inhibitors were present in one sample (2.0%). There was only one sample of the 49 (2.0%) in which the DRMs were of sufficient magnitude to result in a clinical change to drug susceptibility, but even in this sample, the clinical effect of these DRMs was predicted to be low. Significant differences were not observed between the long-term and recent infected population. Differences in DRMs were not observed between peripheral blood mononuclear cells and plasma within an individual. CONCLUSIONS: CRF_BC was the dominant subtype circulating in HIV-1-infected donors in Yunnan. Prevalence of genotypic drug resistances among donors in Yunnan was low in this study. Surveillance on HIV-1 infections among blood donors should be continued in China.
Subject(s)
Blood Donors/statistics & numerical data , Drug Resistance, Viral/genetics , HIV Protease Inhibitors/pharmacology , HIV-1/drug effects , HIV-1/genetics , Adolescent , Adult , China , Enzyme-Linked Immunosorbent Assay , Female , Genes, pol/genetics , Genotype , HIV-1/classification , Humans , Male , Molecular Sequence Data , Phylogeny , Young Adult , pol Gene Products, Human Immunodeficiency Virus/classification , pol Gene Products, Human Immunodeficiency Virus/geneticsABSTRACT
OBJECTIVE: To investigate the subtype characterization of HIV-1 among IDUs in northern Myanmar. DESIGN: A molecular epidemiological investigation was conducted among IDUs in Laza and Maizayang cities of northern Myanmar. METHODS: A total of 83 HIV-1-positive serums were collected from consenting IDUs during June to August 2009. HIV-1 p17, pol, vif-env, C2V3 fragments were amplified and sequenced. Phylogenetic and bootscanning analyses were performed. RESULTS: A very high proportion (86.1%) of HIV-1 intersubtype recombinants and very low proportion of subtypes B' (3.8%), C (7.6%) and CRF01_AE (1.3%) were found in this HIV-infected IDUs cohort. These recombinants cover all four kinds of recombination forms formed among CRF01_AE, B and C. The B/C and CRF01_AE/B/C recombinants are the two most dominant recombinants, accounting for 54.4 and 42.6% of all cases, respectively, and indicating the ongoing generation of extensive and complex HIV-1 recombination among CRF01_AE, B' and C in northern Myanmar. Intriguingly, most recombinants have different chimeric patterns from each other, forming 64 unique recombination forms (URFs) that are quite distinct from any previously identified circulating recombinant forms (CRFs) and URFs in Asia. CONCLUSION: The extremely high proportion of intersubtype recombinants, especially CRF01_AE/B'/C recombinants (42.6%), strongly suggests that northern Myanmar is a big forge for HIV-1 recombination among CRF01_AE, B' and C.
Subject(s)
HIV Infections/epidemiology , HIV-1/genetics , Substance Abuse, Intravenous/epidemiology , Adult , HIV Infections/complications , Humans , Male , Molecular Epidemiology , Myanmar/epidemiology , RNA, Viral/genetics , Recombination, Genetic , Substance Abuse, Intravenous/complicationsABSTRACT
Syncytin is a placenta-specific protein and generally believed to play a pivotal role in syncytiotrophoblast morphogenesis. In this study, transcripts of this gene were quantified by real-time RT-PCR and the translated products were measured by an indirect immunofluorescence assay. Results showed that syncytin was found to be expressed in all nine leukemia and lymphoma cell lines studied albeit at different levels and in 43 peripheral blood samples of 57 leukemia or lymphoma patients. Neither the transcripts nor the translated syncytin was detected in blood samples of normal individuals. In conclusion, peripheral blood syncytin may serve as a marker for leukemia and lymphoma.
Subject(s)
Gene Products, env/metabolism , Leukemia/metabolism , Lymphoma/metabolism , Pregnancy Proteins/metabolism , Blotting, Western , Electrophoresis, Polyacrylamide Gel , Female , Fluorescent Antibody Technique, Indirect , Gene Products, env/genetics , Humans , Leukemia/pathology , Lymphoma/pathology , Male , Pregnancy Proteins/genetics , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
OBJECTIVE: To study the HIV-1 drug resistance (DR) situation among newly infected persons in Dehong. METHODS: 1048 HIV-1 positive blood samples from July to December in 2006 from Dehong prefecture of Yunnan, were collected. HIV drug resistance were tested using TruGene in newly infected people that were distinguished with BED-CEIA, while the subtype were determined with phylogenetic analysis using a set of reference sequences available on the Los Alamos Database. RESULTS: Of sixty-four successfully analyzed samples, drug resistance mutations were detected in 4 samples with the resistance rate as 6.25%. Minor mutation in PR region such as M361/V, L63P and H69K appeared frequently and the rates were 81.25%, 70.31% and 65.63% respectively. The predominantly prevalent strains were seen as C/CRF07 _ BC/08 _ BC(65.63%, 42/64) in this study. CONCLUSION: The prevalence of genotypic drug resistances in HIV-1 recent infections in Dehong prefecture appeared to be at moderate level. Drug-resistance surveillance program among HIV-1 infections should be continued and strengthened.
Subject(s)
Drug Resistance, Viral/genetics , HIV Infections/virology , HIV-1/drug effects , HIV-1/genetics , Adult , Anti-HIV Agents/pharmacology , China , Female , Genotype , HIV Infections/drug therapy , HIV-1/classification , Humans , Male , RNA, Viral/bloodABSTRACT
BACKGROUND: A multi-blood center study was conducted to evaluate a human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) multiplex nucleic acid testing (NAT) donor screening test and to determine the residual risk for HIV-1 and HCV infection. STUDY DESIGN AND METHODS: A commercially available HIV-1 and HCV assay (Procleix, Chiron Corp.) was used for simultaneous detection of HIV-1 RNA and HCV RNA on 89,647 unlinked donor samples. NAT was performed with pools of 16 samples that had passed all routine screening tests. Single-donor NAT was performed for samples that had been disqualified by any reactive screening test result(s). Anti-HCV (Ortho third-generation HCV enzyme immunoassay [EIA]), alanine aminotransferase, and HCV NAT (Roche COBAS Amplicor HCV test) confirmatory tests were used for HCV EIA-nonreactive, HCV NAT-reactive samples. RESULTS: Three HCV NAT yield cases and no HIV-1 yield cases were detected. The yield rate for HCV NAT was 3.4 per 10(5) (95 percent confidence interval [CI], 0.7-9.8). The estimated incidence rate for HCV is 24.2 per 100,000 person-years (95% CI, 3.4-88.0). If minipool NAT is added to routine donor screening, the residual risk for HCV is estimated to be reduced to 1 in 20.4x10(4) (95% CI, 1 in 5.2x10(4)-1 in 165.5x10(4)). CONCLUSION: The residual risk for transfusion-transmitted HCV infection is still relatively high in China. Incorporating NAT technology into blood donor screening would be estimated to reduce the residual risk of HCV infections eightfold over current EIA screening.