Biomedical subjects

Li Jin

Publications and source records attributed to Li Jin.

At least 37 records · Page 2Linked to original sources

PubMed2006

Induction of apoptosis and fibrillin 1 expression in human dermal endothelial cells by scleroderma sera containing anti-endothelial cell antibodies.

OBJECTIVE: Sera from patients with scleroderma (systemic sclerosis [SSc]) contain anti-endothelial cell antibodies (AECAs) capable of inducing endothelial cell apoptosis. We sought to determine whether SSc sera containing anticentromere antibodies (ACAs) or anti-topoisomerase I antibodies (or, anti-Scl-70 antibodies) contain subsets of AECAs that trigger distinct pathways of apoptosis and gene expression in normal adult human dermal endothelial cells (HDECs). METHODS: Adult HDECs were grown to subconfluence and treated with control or SSc patient sera. Apoptosis was investigated by differential interference contrast (DIC) microscopy, microarrays of proapoptotic gene expression, caspase 3 protease activity, and flow cytometry for phosphatidyl serine translocation. RESULTS: Flow cytometry and DIC microscopy demonstrated that HDECs exposed to SSc sera containing either SSc autoantibody underwent apoptosis at much higher levels than those treated with control sera. While unique gene expression profiles were induced in HDECs by stimulation with SSc sera containing the respective autoantibody, similar patterns of increased gene expression of transcripts for the proapoptotic protease caspase 3 as well as the SSc autoantigen fibrillin 1 were demonstrated. Caspase 3 gene expression correlated with increased protease activity, and targeted inhibition of this protease partly blocked SSc serum-induced apoptosis. Immunohistochemistry studies of serum-stimulated HDECs demonstrated the aberrant expression of fibrillin 1 protein only in apoptotic endothelial cells treated with SSc sera containing AECAs. CONCLUSION: There are distinct AECA subsets in the sera of patients with limited SSc (with ACAs) and diffuse SSc (with anti-Scl-70) that induce unique patterns of HDEC gene expression in the setting of apoptosis associated with increased caspase 3 activity and the reexpression of endothelial cell fibrillin 1.

Adult↗

PubMed2006

Investigation of measles and rubella outbreaks in Tamil Nadu, India-2003.

The aims of the present study were to confirm measles outbreaks by detection of measles-specific IgM antibodies, isolation of measles virus, and genetic characterization to document the circulating genotypes in Tamil Nadu. Eight outbreaks were reported from six districts of Tamil Nadu, India during the period Jan-Dec 2003. Blood samples were collected for serology, urine, and throat swabs for virus isolation. Genotypic characterization of measles isolates was based on the sequence of the N gene. All the clinically suspected outbreaks (n = 8) were confirmed by serology; six out of the eight as measles and two as combination of measles and rubella highlighting the need to carry out rubella serology on measles-negative samples. Genetic characterization of three isolates obtained revealed one as genotype D4 and two as D8. Measles genotypes D4 and D8 were found to circulate in three districts of Tamil Nadu. It is necessary to be aware of the circulating genotypes within the geographical area. The information would be valuable to evaluate control measures and identify viral transmission and importation.

Adolescent↗

PubMed2006

Y-chromosome genotyping and genetic structure of Zhuang populations.

Zhuang, the largest ethnic minority population in China, is one of the descendant groups of the ancient Bai-Yue. Linguistically, Zhuang languages are grouped into northern and southern dialects. To characterize its genetic structure, 13 East Asian-specific Y-chromosome biallelic markers and 7 Y-chromosome short tandem repeat (STR) markers were used to infer the haplogroups of Zhuang populations. Our results showed that O*, O2a, and O1 are the predominant haplogroups in Zhuang. Frequency distribution and principal component analysis showed that Zhuang was closely related to groups of Bai-Yue origin and therefore was likely to be the descendant of Bai-Yue. The results of principal component analysis and hierarchical clustering analysis contradicted the linguistically derived north-south division. Interestingly, a west-east clinal trend of haplotype frequency changes was observed, which was supported by AMOVA analysis that showed that between-population variance of east-west division was larger than that of north-south division. O* network suggested that the Hongshuihe branch was the center of Zhuang. Our study suggests that there are three major components in Zhuang. The O* and O2a constituted the original component; later, O1 was brought into Zhuang, especially eastern Zhuang; and finally, northern Han population brought O3 into the Zhuang populations.

Alleles↗

PubMed2006

Search for an association between the human CYP1A2 genotype and CYP1A2 metabolic phenotype.

The genotype responsible for more than 60-fold interindividual differences in human hepatic CYP1A2 constitutive expression is not understood. Resequencing the human CYP1A1_CYP1A2 locus (39.6 kb) in five major geographically isolated subgroups recently led to the identification of 85 single nucleotide polymorphisms (SNPs), 57 of which were double-hit SNPs. Here, we attempted to correlate the CYP1A2 genotype with a metabolic phenotype. We chose 16 SNPs (all having a minor allele frequency > or =0.05 in Caucasians) to genotype 32 DNA samples (26 Caucasians, six Ethiopians) in which CYP1A2 metabolism had previously been determined. From 280 subjects (five locations worldwide) that had been CYP1A2-phenotyped, we genotyped the 10 highest, 14 lowest and eight intermediate DNA samples. Although no SNP was significant (P<0.05), possibly due to the small sample size, we found a trend for several of the six SNPs across the CYP1A2 linkage disequilibrium block associated with the trait. Five CYP1A2 haplotypes were inferred, two of which had not previously been reported; haplotype 1A2H10 showed the greatest association with CYP1A2 activity. Regulatory sequences responsible for the large interindividual differences in hepatic CYP1A2 gene basal expression might reside, in part, with some of these CYP1A2 SNPS but, in large part, might be located either cis (in nearby sequences not yet haplotyped) or trans in that they are not linked to the gene. We conclude that no SNP or haplotype in the CYP1A2 gene has yet been identified that can unequivocally be used to predict the metabolic phenotype in any individual patient.

Alleles↗

PubMed2006

Statistical power of association using the extreme discordant phenotype design.

BACKGROUND: Selective genotyping has been proven to be an effective design for mapping quantitative trait loci (QTL), either by linkage or by allelic association, wherein the individual trait values can be used as the indices for phenotype selection. It has also been proposed that association studies of dichotomous traits can benefit from such design. When there is no quantitative measurement for phenotype available, cases and/or controls having extreme discordant phenotypes (EDP) can still be selected, based on their exposure status to a drug toxicity or environmental risk factor. The advantage of EDP design is intuitive and it has been successfully used in a number of studies. METHODS: In this report, we developed a statistical method to calculate the power of EDP methodology, using a mixture model of genotype-specific distributions of a single biallelic susceptibility locus. We also compared the power of three statistical tests commonly used in association studies - including the chi test of allelic frequencies, the chi test of genotype frequencies, and the Armitage trend test. The power of two different EDP designs was evaluated under a range of scenarios. RESULTS AND CONCLUSION: Our results indicate that the chi test of genotype frequency is a robust, though less powerful, test for single-locus association, and that EDP methodology is a powerful design for genetic association studies - especially those of common diseases caused by quantifiable drug toxicity or environmental risk factors.

Alleles↗

PubMed2006

Is colposcopy needed following laser ablation for dysplasia?

AIMS: To evaluate the effectiveness of cytology and colposcopy in the follow up of women treated by laser CO(2) ablation for cervical intraepithelial neoplasia (CIN). METHODS: A retrospective analysis of 1784 patients with CIN treated with laser CO(2) ablation from 1998 to 2003 at the Royal Women's Hospital, Melbourne. Data were collected prospectively in a computerised colposcopy database utilised in the Dysplasia Unit. RESULTS: There was equal distribution in the study population treated for low-grade intraepithelial neoplasia (LSIL) and high-grade intraepithelial neoplasia (HSIL), with no significant age difference in both groups (mean 27.6 years). The success rate of treatment of LSIL (94%) was similar to that of HSIL (92%). Fifty-seven per cent of all failures occurred within the first year of treatment. Colposcopy was more sensitive in detecting intraepithelial neoplasia (SIL) than cytology, whereas cytology was more specific. No case of cancer was diagnosed on follow up. CONCLUSIONS: CO(2) laser ablation was equally effective in treating different grades of CIN. There is a continuing incidence of recurrent CIN, even up to five years after initial treatment, which suggests that it is necessary for patients to adhere to long-term follow up. The combination of cytology and colposcopic assessment is essential for surveillance of SIL in the initial two years after treatment.

Adult↗

PubMed2006

Polymorphisms in the two helicases ERCC2/XPD and ERCC3/XPB of the transcription factor IIH complex and risk of lung cancer: a case-control analysis in a Chinese population.

The transcription factor IIH (TFIIH) helicases ERCC2/XPD and ERCC3/XPB are responsible for opening the DNA strand around the lesion site during nucleotide excision repair process. Genetic variants in these two genes may be markers for interindividual variability in DNA repair capacity and thus predisposition to cancer risk. In this case-control study of 1,010 incident lung cancer cases and 1,011 age and sex frequency-matched cancer-free controls in a Chinese population, we genotyped eight tagging polymorphisms of ERCC2 and ERCC3 using the high-throughput Taqman platform to determine their associations with risk of lung cancer. Although none of the eight polymorphisms was individually associated with lung cancer risk, we found that genetic variants in ERCC2 and ERCC3 jointly contributed to lung cancer risk in a dose-response manner. Compared with those with 0 to 1 "at-risk" locus, subjects carrying >1 at-risk loci were at increased risk for lung cancer [adjusted odds ratio (OR), 1.29; 95% confidence interval (95% CI), 0.98-1.70 for 2 at-risk loci; adjusted OR, 1.38; 95% CI, 1.02-1.85 for 3 at-risk loci; and adjusted OR, 1.51; 95% CI, 1.09-2.10 for > or =4 at-risk loci, respectively; P(trend) = 0.015]. This combined effect was slightly more evident in young subjects (<60 years), males, current smokers, and those with family history of cancer, particularly for histologic type of adenocarcinomas. No evidence for interaction was found. These findings indicate that these tagSNPs of the ERCC2 and ERCC3 along with their surrounding regions may serve as biomarkers of susceptibility to lung cancer, which warrant further validation by other population-based and phenotypic studies to determine the biological relevance of these tagSNPs.

Adenocarcinoma↗

PubMed2006

[Analysis of polymorphisms in Y-DNA haplotypes and mtDNA haplogroups in Yao ethnic group from Guizho].

The frequencies of Y-chromosome haplotypes consisting of 12 single nucleotide polymorphisms (SNP) and mitochondrial DNA (mtDNA) haplotypes consisting of 9 SNPs were investigated using PCR-RFLP in 97 Yaos from Guizhou to study the patrilineal and matrilineal genetic structure and the origin of Yao Ethnic Group from Guizhou. Results showed that all 97 samples were classified into 4 Y-DNA haplotypes (H7, H8, H9 and H11). The major haplotype H7 of Hmong-Mien Population was highly prevalent (92.4%) in Yaos from Guizhou. Eight mtDNA haplotypes were identified through mtDNA analysis and all the haplotypes could be classified into 5 haplogroups (B4, B5, D4, D5 and N*) that were defined previously. The frequency of a 9-bp deletion in the human mtDNA Co II/tRNALys intergenic region was 58.2% in the 97 samples. These data suggest that the patrilineal genetic structure of Yao ethnic group from Guizhou was simple and Yaos from Guizhou had the typical genetic character of the Hmong-Mien Population and some admixture with other populations. The matrilineal genetic structure of Yaos from Guizhou was relatively complex and the 9-bp deletion was a characteristic genetic marker of the matrilineal genetic structure of Yaos from Guizhou.

Asian People↗

PubMed2006

[Association between endothelial nitric oxide synthase gene (G894T) polymorphism and essential hypertension in Uygur populations].

OBJECTIVE: To investigate the association between G894T polymorphism and essential hypertension (EH) in Uygur population in Xinjiang province. METHODS: In this case-control study, G894T genotypes in 375 hypertension patients (EH group) and 414 normotensive control subjects (NT group) from the rural area of Tuluafan of Xinjiang was investigated by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: (1) Significant differences were found in GG, GT and TT frequencies of G894T genotypes between the EH and NT groups (56.5%, 28.3%, 15.2% in EH group and 65.9%, 22.5%, 11.6% in NT group, OR = 2.97, 95% CI 1.393 - 6.358). T allele frequencies were significantly higher in EH group (29.33%) than that in NT group (22.83%, P < 0.05). (2) SBP, DBP in patients with T allele of eNOS gene [(171.36 +/- 22.30) mm Hg and (103.63 +/- 13.22) mm Hg] were significantly higher than that of GG genotype [(158.07 +/- 20.850) mm Hg and (89.90 +/- 10.39) mm Hg] (P < 0.01). CONCLUSIONS: eNOS gene exon7 G894T polymorphism might relate to essential hypertension in Uygur population in Xinjiang province.

Aged↗

PubMed2006

[Genetic polymorphism of HLA-Cw locus in hematopoietic stem cell transplantation patient and donor population].

OBJECTIVE: To analyze the distribution of genes in HLA-Cw locus from Han population of China in a large scale, and to provide basic data for further study on the genetic characteristics of HLA-Cw locus of this population. METHODS: Totally 1285 unrelated Chinese Han individuals were typed by PCR-SSP, and statistics was utilized to investigate the distribution rules of detected genes. RESULTS: Twenty-three HLA-Cw alleles were identified in Chinese Han population, out of them HLA-Cw*01, *03, *07 and *08 were the commonest genes, which accounted for frequencies of 0.1529, 0.2385, 0.1747 and 0.1004, respectively. Five genes which could not be identified by serological method were deaed: HLA-Cw*12, *14, *15, *16 and *17. Hardy-Weinberg test showed that the observed genetic polymorphism distribution values were correspondent with the expected (chi-square=73.74, df=98, P>0.5). CONCLUSION: This study may serve a full-scale scientific genetic parameters of HLA-Cw genes for Chinese Han population studies.

Adolescent↗

PubMed2005

Demineralized bone matrix gelatin as scaffold for osteochondral tissue engineering.

To develop a single-unit osteochondral tissue with demineralized bone matrix gelatin (BMG), rabbit chondrocytes were cultured on demineralized bone matrix gelatin for 6 weeks. The engineered osteochondral tissue was characterized with histology, immunolocalization, TEM, SEM, biochemical assay, and gene expression analysis. About 1.3mm viable neo-cartilage was produced on demineralized BMG. RT-PCR, immunohistochemistry, TEM, biochemical assay, and histology revealed hyaline-like cartilage with zonal layers, intense type II collagen expression, and abundant proteoglycan content formed upon BMG compared with normal cartilage. But hydroxyproline content and type I collagen gene and protein expressions were significantly lower. We consider engineering cartilage tissue with chondrocytes cultured on allogenic demineralized BMG is a good approach for osteochondral tissue engineering.

Animals↗

PubMed2005

Mutations in tap uncouple RNA export activity from translocation through the nuclear pore complex.

Interactions between transport receptors and phenylalanine-glycine (FG) repeats on nucleoporins drive the translocation of receptor-cargo complexes through nuclear pores. Tap, a transport receptor that mediates nuclear export of cellular mRNAs, contains a UBA-like and NTF2-like folds that can associate directly with FG repeats. In addition, two nuclear export sequences (NESs) within the NTF2-like region can also interact with nucleoporins. The Tap-RNA complex was shown to bind to three nucleoporins, Nup98, p62, and RanBP2, and these interactions were enhanced by Nxt1. Mutations in the Tap-UBA region abolished interactions with all three nucleoporins, whereas the effect of point mutations within the NTF2-like domain of Tap known to disrupt Nxt1 binding or nucleoporin binding were nucleoporin dependent. A mutation in any of these Tap domains was sufficient to reduce RNA export but was not sufficient to disrupt Tap interaction with the NPC in vivo or its nucleocytoplasmic shuttling. However, shuttling activity was reduced or abolished by combined mutations within the UBA and either the Nxt1-binding domain or NESs. These data suggest that Tap requires both the UBA- and NTF2-like domains to mediate the export of RNA cargo, but can move through the pores independently of these domains when free of RNA cargo.

ATP-Binding Cassette Transporters↗

PubMed2005

Beta-2 adrenergic receptor gene (ADRB2) polymorphism and risk for lung adenocarcinoma: a case-control study in a Chinese population.

The incidence of lung adenocarcinoma (AC) has been increasing over recent decades. The tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the most potent carcinogens and reproducibly induces a high incidence of lung AC in laboratory animals. In addition to its genotoxic effects, NNK has also epigenetic effects on lung cells by functioning as an agonist for beta adrenergic receptors and stimulating the signal pathways that lead to lung AC. Beta-2 adrenergic receptor (ADRB2) expressed on bronchial smooth muscle is a well-defined target for asthma treatment that has epidemiological implications in lung cancer development. And biochemical effect and pharmacogenetic relevance of regulatory and coding variants of ADRB2 have been well documented. Aiming to test whether the genetic variants of ADRB2 modify risk of lung AC, we compared the manifestation of three common single nucleotide polymorphisms (SNPs) of ADRB2 (G-1023A, G-654A, and A46G (Gly16Arg)) between 313 patients with lung AC and 321 controls. Overall association was not observed between risk and either individual of the three SNPs or their combined haplotypes. However, in the subgroup of young subjects < or =50 years old, significant association was observed for G-1023A (allele based OR, 1.82; 95% CI, 1.12-2.95), A46G (Gly16Arg) (allele based OR, 0.64; 95% CI, 0.40-1.03), and the haplotype A(-1023)A(46) (OR 2.62; 95% CI 1.30-5.27). Our results do not support a major independent role of ADRB2 polymorphisms in lung AC risk, suggesting that functional variants of other genes involved in the NNK epigenetic pathway of carcinogenesis should be investigated.

Asian People↗

PubMed2005

Genetic variability of measles virus in acute and persistent infections.

RNA viruses have high nucleotide substitution rates, and therefore the potential to mutate rapidly. In the case of vaccine preventable RNA viruses, this may potentially lead to emergence of vaccine escape mutants. The WHO has targeted measles virus (MV) for elimination in many regions, and its genetic variability is monitored to estimate appearance of such mutants. Phylogenetic analysis of partial N or H genes of 230 MV strains circulating in the UK over a 10-year period was performed. Substitution rates in three outbreaks were determined to be 3.9 x 10(-3) to 6.7 x 10(-3) per nucleotide per annum. This is an order of magnitude higher than previously reported for circulating MV. Analysis of virus detected sporadically in the UK between 1992 and 2000 lead to a slightly higher substitution rate of 7.8 x 10(-3) per site per year. Additionally, genetic variability of persistent MV, isolated from subacute sclerosing panencephalitis (SSPE) patients, was investigated and appeared more stable than circulating viruses. Profiles of nucleotide changes in acute and persistent virus were compared. In acute virus, 33% of all mutation events occurred from A-to-G, which contrasts the predominant U-to-C mutations found in persistent infections. Mutations do not seem to be driven by positive selection and no association with known biological functions could be found. We conclude that substitution rates in circulating virus may be higher than in persistent, hypermutated virus and that the high substitution rate of MV may allow evolution of escape. Diversity of circulating strains should be closely monitored in the future.

Acute Disease↗

PubMed2005

[Infection of Helicobacter pylori strains with multiple vacA m-region subtypes and/or iceA mixed genotype among the Bai, Naxi, and Han populations in Yunnan province].

OBJECTIVE: To study the epidemiology and pathogenicity of mixed infection of Helicobacter pylori (H. pylori) strains with multiple vacA m-region subtypes and/or iceA mixed genotype among the Bai, Naxi, and Han populations in Yunnan province. METHODS: Gastric mucous membrane were obtained by gastroscopy from 444 patients with digestive ulcer or chronic gastritis, 165 of Han nationality, 117 of Bai nationality, and 162 of Naxi nationality. H. pylori was isolated from 109 patients and cultured. RT-PCR was used to detect the Helicobacter pylori strains vacA gene subtype and iceA genes. RESULTS: The overall rates of vacA gene s1 type and vacA gene s2 type were 98.2% (107/109) and 1.8% (2/109) respectively. The overall rates of vacA gene m2 type, vacA gene m1a type, vacA gene m1b type, and mixed types were 45.9% (50/109), 0.9% (1.109), 23.9% (26/109), and 11% (12/109) respectively; and m region was not identified in 18.3% (20/109) of the strains. The overall rates of iceA1 and iceA2 genes were 67.0% (73/109) and 41.3% (45/109) respectively. In the specimens from the patients of Bai nationality, as regards the s region, only s1 type was identified in all specimens; the rates of vacA gene m2 type, vacA gene m1a type, vacA gene m1b type, and mixed type were 45.2% (14/31), 3.2% (1/31), 12.9% (4/31), and 16.2% (5/31) respectively, and m region was not identified in 22.6% of the strains; and the rates of iceA1 and iceA2 were 87.1% (27/31) and 61.3% (19/31) respectively. In the specimens from the patients of Naxi nationally, The rates of vacA gene s1 type and s2 type were 95.6% (43/45) and 4.4% (2/45), the rates of vacA gene m2 type, vacA gene m1b type, and mixed m-type were 33.3% (15/45), 37.8% (17/45), and 6.7% (3/45) respectively, no m1a type was found, and m region was not identified in 22.2% of the strains; the rates of iceA1 and iceA2 were 48.9% (22/45) and 31.1% (14/45) respectively. In the specimens of the patients of Han nationality, as regards the s region, all specimens were s1 type; the rates of vacA gene m2 type, vacA gene m1b type, and mixed type were 63.6% (21/33), 15.2% (5/33), and 12.1% (4/33) respectively, and m region was not identified in 9.1% (3/33) of the strains; the rates of iceA1 and iceA2 were 72.7% (24/33) and 36.4% (12/33) respectively. 34 of the 109 patients (31.2%) suffered from mixed infection of vacA gene m mixed subtype and/or iceA mixed genotype, 64.7% of which (22/34) suffering iceA1 + iceA2 infection, 23.5% of which (8/34) being iceA + vacA mixed infection, and 11.8% of which (4/34) being vacA subtype mixed infection, with the former incidence of the former group significantly higher than those of the 2 latter groups (both P < 0.001). The mixed infection rate of the Bai nationality (67.7%, 21/31) was significantly higher than those of the Naxi nationality (20.0%, 9/45, P < 0.001) and Han nationality (12.1%, 4/33, P > 0.001) without a significant difference between the Naxi and Han nationalities (P > 0.05). The mixed infection rate of iceA1 + iceA2 of the Bai nationality (61.3%, 19/31) was significantly higher than those of the Naxi nationality (17.8%, 8/45, P < 0.001) and Han nationality (9.1%, 3/33, P < 0.001) without a significant difference between the Naxi and Han nationalities (P > 0.05). The mixed rate of the patients with digestive ulcer was 30.2% (16/53), not significantly different from that of the patients with chronic gastritis (32.1%, 18/56, P > 0.05). 16 of the 34 cases of mixed infection were patients of digestive ulcer; and 8 of the 34 cases were patients with chronic gastritis. 8 of the 34 cases (23.5%) of mixed infection were cases of infection of vacA gene m mixed subtypes and iceA mixed genotype; among which 7 were patients with digestive ulcer and 1 case was patient of chronic gastritis. Thus the rate of vacA gene m mixed subtypes and iceA mixed genotype was 43.8% (7/16) in the patients with digestive ulcer, significantly higher than in the patient with chronic gastritis (5.6%, 1/18, P = 0.014). 22 of the 34 cases of mixed infection (64.7%) suffered from infection of iceA mixed gene subtypes. Among these 22 cases 15 were patients with chronic gastritis and 7 were patients with digestive ulcer. Thus the rate of iceA mixed subtypes infection was 43.8% (7/16) in the patients with digestive ulcer, significantly lower than in the patient with chronic gastritis (83.3%, 15/18, P = 0.016). In the 21 mixed infection patients of Bai nationality, the rate of vacA gene mixed sybtype + iceA gene mixed subtypes infection was 100% in the patients with digestive ulcer (100%, 5/5), significantly higher than that of single vacA gene subtype + iceA gene mixed subtypes (37.5%, 6/16, P = 0.0258). The mixed infection rate of H. pylori strains was 32.1%. CONCLUSION: The mixed infection rate of the Bai nationality is higher than those of the Han and Naxi nationalities. Detection of mixed infection by vacA genotypes is more sensitive in Han populations. Detection of multiple infections by iceA gene mixed subtypes is more sensitive in Bai and Naxi populations.

Bacterial Proteins↗

PubMed2005

Y-chromosome evidence of southern origin of the East Asian-specific haplogroup O3-M122.

The prehistoric peopling of East Asia by modern humans remains controversial with respect to early population migrations. Here, we present a systematic sampling and genetic screening of an East Asian-specific Y-chromosome haplogroup (O3-M122) in 2,332 individuals from diverse East Asian populations. Our results indicate that the O3-M122 lineage is dominant in East Asian populations, with an average frequency of 44.3%. The microsatellite data show that the O3-M122 haplotypes in southern East Asia are more diverse than those in northern East Asia, suggesting a southern origin of the O3-M122 mutation. It was estimated that the early northward migration of the O3-M122 lineages in East Asia occurred approximately 25,000-30,000 years ago, consistent with the fossil records of modern humans in East Asia.

Chromosomes, Human, Y↗

PubMed2005

Genome amplification of single sperm using multiple displacement amplification.

Sperm typing is an effective way to study recombination rate on a fine scale in regions of interest. There are two strategies for the amplification of single meiotic recombinants: repulsion-phase allele-specific PCR and whole genome amplification (WGA). The former can selectively amplify single recombinant molecules from a batch of sperm but is not scalable for high-throughput operation. Currently, primer extension pre-amplification is the only method used in WGA of single sperm, whereas it has limited capacity to produce high-coverage products enough for the analysis of local recombination rate in multiple large regions. Here, we applied for the first time a recently developed WGA method, multiple displacement amplification (MDA), to amplify single sperm DNA, and demonstrated its great potential for producing high-yield and high-coverage products. In a 50 mul reaction, 76 or 93% of loci can be amplified at least 2500- or 250-fold, respectively, from single sperm DNA, and second-round MDA can further offer >200-fold amplification. The MDA products are usable for a variety of genetic applications, including sequencing and microsatellite marker and single nucleotide polymorphism (SNP) analysis. The use of MDA in single sperm amplification may open a new era for studies on local recombination rates.

Genomics↗

PubMed2005

[Clinical observation of propofol combined with misoprostol for painless induced abortion].

OBJECTIVE: To observe the effects of propofol combined with misoprostol for painless induced abortion. METHODS: Two hundred early pregnant women, nullipara or pluripara with history of cesarean section, were randomly divided into two groups: control group receiving intravenous injection of propofol 2.5 mg/kg and then underwent induced abortion after becoming unconscious, and experimental group receiving misoprostol 200 microg intravaginally two hours before undergoing induced abortion. The effects on anesthesia, cervix dilatation, uterotonic degree, bleeding and abortion syndrome were observed. RESULTS: Anesthesia was 100% effective in both groups. No induced abortion syndrome occurred. For the effect on cervical dilatation, No.6 Hegars dilator were smoothly inserted into the cervical canal in 96 cases (96%) in the experimental group and in only 8 cases (8%) in the control group (P < 0.01). For the effect on uterotonic degree, 79 cases in the experimental group (79%) and 30 cases in the control group (30%) showed 1 approximately 2 cm of uterine contraction (P < 0.01). Seventy-five cases in the experimental group (75%) and 25 cases in the control group (25%) showed blood loss of less than 15 ml (P < 0.01). CONCLUSION: Intravenous injection of propofol combined with misoprostol administered intravaginally is effective in anesthesia and cervical dilatation with less bleeding and absence of abortion syndrome.

Abortion, Induced↗