Interleukin 17A rs4711998 A>G polymorphism was associated with a decreased risk of esophageal cancer in a Chinese population

Esophageal cancer is the eighth most common cancer and sixth leading cause of cancer-associated death worldwide. Besides environmental risk factors, genetic factors might play an important role in the esophageal cancer carcinogenesis. We conducted a hospital-based case-control study to evaluate the genetic effects of functional single nucleotide polymorphisms (SNPs) in the interleukin 17A (IL17A) gene on the development of esophageal cancer. A total of 380 esophageal squamous cell carcinoma (ESCC) cases and 380 controls were recruited for this study. The genotypes were determined using a custom-by-design 48-Plex SNPscan Kit. IL17A rs4711998 A>G polymorphism was associated with the decreased risk of ESCC. When the IL17A rs4711998 AA homozygote genotype was used as the reference group, the AG genotype was associated with a significantly decreased risk for ESCC (AG vs. AA: adjusted odds ratio 0.72, 95% confidential interval 0.53-0.98, P = 0.039). However, there was no significant association between the other five SNPs and ESCC risk. Stratified analyses indicated that a significantly decreased risk of ESCC associated with the IL17A rs4711998 A>G polymorphism was evident among younger patients and patients who never smoking or drinking. These findings indicated that functional polymorphism IL17A rs4711998 A>G might contribute to ESCC susceptibility. However, our results were obtained with a limited sample size; the power of our analysis was low. Future larger studies with more rigorous study designs of other ethnic populations are required to confirm current findings.

Application of a global reference for fetal-weight and birthweight percentiles in predicting infant mortality

OBJECTIVE

To determine whether the recently published A global reference for fetal-weight and birthweight percentiles (Global Reference) improves small- (SGA), appropriate- (AGA), and large-for-gestational-age (LGA) definitions in predicting infant mortality.

DESIGN

Population-based cohort study.

SETTING

The US Linked Livebirth and Infant Death records between 1995 and 2004.

POPULATION

Singleton births with birthweight >500 g born at 24-41 weeks of gestation.

METHODS

We compared infant mortality rates of SGA, AGA, and LGA infants classified by three different references: the Global Reference; a commonly used birthweight reference; and Hadlock's ultrasound reference.

MAIN OUTCOME MEASURES

Infant mortality rates.

RESULTS

Among 33 997 719 eligible liveborn singleton births, 25% of preterm and 9% of term infants were classified differently for SGA, AGA, and LGA by the Global Reference and the birthweight reference. The Global Reference indicated higher mortality rates in preterm SGA and preterm LGA infants than the birthweight reference. The mortality rate was considerably higher in infants classified as preterm SGA by the Global Reference but not by the birthweight reference, compared with the corresponding infants classified by the birthweight reference but not by the Global Reference (105.7 versus 12.9 per 1000, RR 8.17, 95% CI 7.38-9.06). Yet, the differences in mortality rates were much smaller in term infants than in preterm infants. Black infants had a particularly higher mortality rate than other races in AGA and LGA preterm and term infants.

CONCLUSIONS

In respect to the commonly used birthweight reference, the Global Reference increases the identification of infant deaths by improved classification of abnormal newborn size at birth, and these advantages were more obvious in preterm than in term infants.

Herpes simplex virus type 2 incidence and associated risk factors among female sex workers in a high HIV-prevalence area of China

Herpes simplex virus type 2 (HSV-2) can contribute to the spread of HIV. From March 2006 to November 2009, female sex workers (FSWs) in Yunnan, China were recruited into an open cohort study to determine incidence and risk factors for HSV-2 acquisition. Participants were interviewed and tested for HSV-2 and other sexually transmitted infections (STIs) every six months. A multivariate Cox proportional hazards regression model with time-dependent variables was used to measure associations with HSV-2 acquisition. In 3.5 years, 83 incident cases of HSV-2 infection were diagnosed, yielding an overall incidence of 21.9 per 100 person years (PY) (95% confidence interval [CI], 17.8-26.3). Working in higher risk commercial sex venues, current Neisseria gonorrhoeae infection, age of sexual debut <18 years and lack of a regular sex partner were independent factors associated with HSV-2 acquisition. The high incidence of HSV-2 suggests that prevention methods for HIV/STI control are urgently needed.

Role of Etv2-positive cells in the remodeling morphogenesis during vascular development

Etv2 is a critical determinant for the commitment of endothelial (EC) and hematopoietic (HPC) cells from mesoderm. Etv2 is assumed to be transiently required for EC commitment but dispensable after most ECs differentiate around E9.5. To confirm the time window of Etv2 requirement, Etv2 was ablated at different time points using ROSA26CreER mice. Unexpectedly, Etv2 ablation at E9.5 caused vascular remodeling defects in cranial and yolk sac vasculature. Immunostaining showed that Etv2+/VE-cadherin (VECAD)- cells were present around forming vasculature, mostly co-expressing Flk-1 with a small number of Etv2+/VECAD+ cells, indicating that Etv2+/Flk-1+/VECAD- cells are the major Etv2+ population promoting vascular remodeling around E9.5. Gene expression analysis showed up-regulation of Fgf proteins, Il-6, Glypican-3 and matrix metalloproteases in Etv2+/VEDAC- cells over Etv2-/VECAD+ mature ECs. Blockade of those factors caused reduced EC sprouting in ex vivo explant culture from E9.5 embryos, suggesting the functional significance of environmental factors derived from Etv2+ cells. Altogether, we propose that Etv2+/VEDAC- cells around E9.5-E10.5 provide extracellular factors to complete vascular morphogenesis in addition to becoming differentiated ECs incorporated into vessels. This insight for the new role of Ets protein in perivascular Flk-1+/VECAD-/(Etv2+) cells to induce expression of angiogenic factors may provide another strategy to control angiogenesis.

Production of S-acetoin from diacetyl by Escherichia coli transformant cells that express the diacetyl reductase gene of Paenibacillus polymyxa ZJ-9

S-acetoin (S-AC) is an important four-carbon chiral compound that has unique industrial applications in the asymmetric synthesis of valuable chiral specialty chemicals. However, previous studies showed that the usually low yield and optical purity of S-AC as well as the very high substrate cost have hindered the application of this compound. In the current work, a gene encoding diacetyl reductase (DAR) from a Paenibacillus polymyxa strain ZJ-9 was cloned and expressed in Escherichia coli. Whole cells of the recombinant E. coli were used to produce S-AC from diacetyl (DA). Under optimal conditions, S-AC with high optical purity (purity >99·9%) was obtained with a yield of 13·5 ± 0·24 and 39·4 ± 0·38 g l(-1) under batch and fed-batch culture conditions, respectively. This process featured the biotransformation of DA into S-AC using whole cells of engineered E. coli. The result is a considerable increase in the yield and optical purity of S-AC, which in turn facilitated the practical application of the compound.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrated a highly efficient new method to produce S-acetoin with higher than 99·9% optical purity from diacetyl using whole cells of engineered Escherichia coli. It will therefore decrease the production cost of S-acetoin and highlight its application in asymmetric synthesis of highly valuable chiral compounds.

Associations between drug use and risk behaviours for HIV and sexually transmitted infections among female sex workers in Yunnan, China

This is a cross-sectional study of 399 subjects conducted to explore the association between drug use and risk behaviour for HIV and sexually transmitted infections (STIs) among female sex workers (FSWs), and also to study the prevalence of HIV/STIs among drug-using FSWs (DUFSWs) and non-DUFSWs in Yunnan province of China. Demographic information, mobility, sexual and drug-using behaviours were collected and subjects were tested for HIV/STIs. Mean age was 27 years (SD = ±7.8) and 94 (23.6%) tested positive for recent opiate use. Compared with non-DUFSWs, DUFSWs had a significantly higher prevalence of HIV (38% versus 4%, P ≤ 0.001), herpes simplex virus type 2 (HSV-2; 92% versus 60%, P ≤ 0.001) and STIs (95.7% versus 69.2%, P ≤ 0.001). DUFSWs had a significantly longer duration of commercial sex work compared with non-DUFSWs (median 5 versus 1 years, P ≤ 0.001), and had at least two clients in the last working day. DUFSWs were also more likely to work in low-end commercial sex venues and frequented a greater number of work locations than non-DUFSWs. Compared with non-DUFSWs, DUFSWs were more likely to exhibit riskier sexual behaviours and greater workplace mobility. Interventions targeting drug-related behavioural changes are needed urgently in this population in order to reduce rates of HIV and STIs.

Molecular characterization and population genetic diversity of Limonium sinense based on nuclear ribosomal DNA and ISSR

The single nucleotide polymorphism (SNP) and amplification refractory mutation system (ARMS) have been applied to authenticate Limonium species and their corresponding herb samples. One species specific primer was designed and the amplification product is 200 bp (Limonium sinense) by using this primer. No band was observed with other Limonium species. The phylogenetic relationship of Limonium species were studied using ribosomal DNA ITS and the adulterants (L. bicolor, L. aureum and L. wrightii) were clustered with L. sinense in NJ tree. Inter simple sequence repeat (ISSR) was used to assess genetic diversity and population structure of L. sinense and a high level of genetic diversity was detected (H(E) = 0.2573, PPB = 85.71%) with POPGENE. Based on AMOVA analysis, there was moderate variation between pairs of populations with phi(ST) from 0.1744 to 0.5131 and on average 28.81% of the genetic variation occurred among populations. Five main clusters were shown in UPGMA dendrogram using TFPGA. The results showed that SNP and ARMS could be used to authenticate not only Limonium species but related herbs on rDNA internal transcribed spacer region. Possible strategies should be implemented for conservation of this endemic herb.

PDGF receptor alpha+ mesoderm contributes to endothelial and hematopoietic cells in mice

BACKGROUND

Early mesoderm can be classified into Flk-1+ or PDGF receptor alpha (PDGFRα)+ population, grossly representing lateral and paraxial mesoderm, respectively. It has been demonstrated that all endothelial (EC) and hematopoietic (HPC) cells are derived from Flk-1+ cells. Although PDGFRα+ cells give rise to ECs/HPCs in in vitro ES differentiation, whether PDGFRα+ population can become hemato-endothelial lineages has not been proved in mouse embryos.

RESULTS

Using PDGFRαMerCreMer mice, PDGFRα+ early mesoderm was shown to contribute to endothelial cells including hemogenic ECs, fetal liver B lymphocytes, and Lin-Kit+Sca-1+ (KSL) cells. Contribution of PDGFRα+ mesoderm into ECs and HPCs was limited until E8.5, indicating that PDGFRα+/Flk-1+ population that exists until E8.5 may be the source for hemato-endothelial lineages from PDGFRα+ population. The functional significance of PDGFRα+ mesoderm in vascular development and hematopoiesis was confirmed by genetic deletion of Etv2 or restoration of Runx1 in PDGFRα+ cells. Etv2 deletion and Runx1 restoration in PDGFRα+ cells resulted in abnormal vascular remodeling and rescue of fetal liver CD45+ and Lin-Kit+Sca-1+ (KSL) cells, respectively.

CONCLUSIONS

Endothelial and hematopoietic cells can be derived from PDGFRα+ early mesoderm in mice. PDGFRα+ mesoderm is functionally significant in vascular development and hematopoiesis from phenotype analysis of genetically modified embryos.

[Association between the myeloperoxidase gene polymorphisms and the susceptibility to prostate cancer: a case-control study in a Chinese population]

BACKGROUND AND OBJECTIVES

Prostate cancer (PCa) is the most common cancer among men in most western populations. The polymorphisms of the myeloperoxidase (MPO) gene have been correlated with abnormal MPO expression and increased risk of various types of cancers. Our study aimed to evaluate the association between the genetic polymorphisms and the risk of prostate cancer.

METHODS

Genotyping was carried out by using the genotyping system (MassARRAY iPLEX; Sequenom, Inc., San Diego, CA, USA) on 1,108 PCa patients and 1,525 cancer-free controls in a Chinese Han population.

RESULTS

Although one SNP (rs8082134, P < 0.050) was significant, it is very rare and unstable. Other SNPs had no significant difference between genotype distributions in the PCa patients and the control group. Totally, SNPs in the MPO gene is not associated with PCa risk.

CONCLUSION

Our data showed a limited association between the MPO SNPs and the susceptibility to PCa in population of Chinese Han population. The possible association of rs8082134 of MPO with PCa risk need further clarification.

Isolation and characterization of microsatellite markers in Chinese herb of Dendrobium loddigesii

As an invaluable herb, Dendrobium loddigesii is widely used in Chinese medicinal field. In order to develop a convenient and efficient identification method and investigate the genetic diversity and structure of this species, twelve microsatellite loci were isolated from two microsatellite-enriched libraries. Twenty-six individuals from Baise population were analysed. The observed and expected heterozygosities ranged from 0.174 to 0.617 and from 0.182 to 0.608, respectively. These microsatellite loci characterized from D. loddigesii will contribute to research on the individual authentication, population structure, genetic diversity and conservation of this species and its similar species.