Estimation of bisphenol A (BPA) concentrations in pregnant women,fetuses and nonpregnant women in Eastern Townships of Canada

We determined bisphenol A (BPA) concentrations of 61 pregnant women (PW), their fetuses and 26 nonpregnant women (NPW) in Eastern Townships of Canada; and evaluated potential correlations between maternal and fetal blood, and between peripheral blood and peritoneal fluid. In PW, BPA levels were ranged from non-detected to 4.46 ng/ml and from non-detected to 4.60 ng/ml for maternal and fetal serum, respectively. In NPW, BPA levels were ranged from 1.30 to 8.17 ng/ml and from 0.19 to 13.45 ng/ml for serum and peritoneal fluid, respectively. Positive correlation was found between maternal and fetal serum, and between serum and peritoneal fluid. In conclusion, our findings highlight a continuous distribution of BPA between the mother and its fetus and reveal a role of pregnancy in underestimating the actual levels of blood BPA. Our study also provides a temporal-spatial reference on BPA exposure, which is a useful tool in monitoring, comparing and correcting.     

Immunogenicity and therapeutic effects of recombinant Ag85AB fusion protein vaccines in mice infected with Mycobacterium tuberculosis

The immune function of tuberculosis (TB) patients is disordered. By using immune regulators to assist chemotherapy for TB the curative effect might be improved. In this study, a vaccine containing Mycobacterium tuberculosis (M. tuberculosis) recombinant Ag85AB fusion protein (rAg85AB) was constructed and evaluated. The mice were immunized intramuscularly three times at two-week intervals with Ag85AB fusion protein combined with Corynebacterium parvum adjuvant (rAg85AB+CP). In comparison to control mice that received either CP alone or saline, the mice that received rAg85AB+CP had significantly higher number of T cells secreting IFN-γ and higher levels of specific antibodies of IgG, IgG1 and IgG2a isotypes in sera. The specific antibodies also had higher ratios of IgG2a to IgG1, indicating a predominant Th1 immune response. To test for immunotherapy of TB, M. tuberculosis infected mice were given three intramuscular doses of 20 μg, 40 μg or 60 μg of rAg85AB in rAg85AB+CP, or phosphate-buffered saline (PBS), or CP or Mycobacterium phlei (M. Phlei) F.U.36. Compared with the PBS group, 20 µg, 40 µg and 60 µg rAg85AB+CP and M. phlei F.U.36 groups reduced the pulmonary bacterial loads by 0.13, 0.15, 0.42 and 0.40 log₁₀, and the liver bacterial loads by 0.64, 0.64, 0.53 and 0.61 log₁₀, respectively. Pathological changes of lungs were less, and the lesions were limited to a certain extent in 40 µg and 60 µg rAg85AB+CP and M. phlei F.U.36 groups. These results showed that rAg85AB+CP had immunotherapeutic effect on TB, significantly increasing the cellular immune response, and inhibiting the growth of M. tuberculosis.     

Phylogenetic and recombination analysis of human bocavirus 2

Background  

Human bocavirus 2(HBoV2) and other human bocavirus species (HBoV, HBoV3, and HBoV4) have been discovered recently. But the precise phylogenetic relationships among these viruses are not clear yet.     

Molecular characterization of astrovirus infection in children with diarrhea in Beijing, 2005–2007

Human astroviruses (HAstVs) have been recognized as one of the major causes of acute gastroenteritis in children. To provide more insight into the prevalence of HAstV gastroenteritis in China, 664 fecal samples were collected from children affected with acute gastroenteritis in Beijing from March 2005 to November 2007. The samples were analyzed genetically. All eight serotypes (genotypes) of HAstVs were screened using RT‐PCR assays targeting the ORF2 region in the study. The assays detected HAstVs in 52 (7.8%) of the patients, with HAstV‐1 (50/52) being the dominant genotype during the study period. Two minor genotypes, HAstV‐6 and HAstV‐3, were also detected. Partial sequencing of the 50 HAstV‐1 strains showed that the homology of the nucleotide sequence of the ORF1a region between these strains was 88.4–100%, whereas the homology of the amino acid sequences was 95.6–100%. In the ORF2 partial region, the nucleotide identities ranged from 91.5% to 100%, and amino acid identities ranged from 97.3% to 100%. The identity of the whole genome sequence between four randomly examined HAstV‐1 strains was 91–99%. No recombination events were observed in HAstVs in this study. The findings of this study will provide baseline data for HAstVs surveillance and control. J. Med. Virol. 82:415–423, 2010. © 2010 Wiley‐Liss, Inc.     

Epidemiological investigations of human rabies in China

Background  

The epidemic of rabies showed a rising trend in China in recent years. To identify the potential factors involved in the emergence, we investigated and analyzed the status and characteristics of human rabies between 1996 and 2008. Moreover, the status of rabies infection and vaccination in dogs, and prophylaxis of humans after rabies exposure were analyzed.     

Development of genetically engineered CD4+ and CD8+ T cells expressing TCRs specific for a M. tuberculosis 38-kDa antigen

Cell-mediated immunity is critical to the clearance of Mycobacterium tuberculosis due to the primarily intracellular niche of this pathogen. Adoptive transfer of M. tuberculosis-specific effector T cells has been shown to confer immunity to M. tuberculosis-infected recipients resulting in M. tuberculosis clearance. However, it is difficult to generate sufficient numbers of M. tuberculosis antigen-specific T cells in a short time. Recent studies have developed T cell receptor (TCR) gene-modified T cells that allow for the rapid generation of large numbers of antigen-specific T cells. Many TCRs that target various tumor and viral antigens have now been isolated and shown to have functional activity. Nevertheless, TCRs specific for intracellular bacterial antigens (including M. tuberculosis antigens) have yet to be isolated and their functionality confirmed. We isolated M. tuberculosis 38-kDa antigen-specific HLA class I and class II-restricted TCRs and modified the TCR gene C regions by substituting nine amino acids with their murine TCR homologs (minimal murinization). Results showed that both wild-type and minimal murinized TCR genes were successfully cloned into retroviral vectors and transduced into primary CD4⁺ and CD8⁺ T cells and displayed anti-M. tuberculosis activity. As expected, minimal murinized TCRs displayed higher cell surface expression levels and stronger anti-M. tuberculosis activity than wild-type TCRs. To the best of our knowledge, this is the first report describing TCRs targeting M. tuberculosis antigens and this investigation provides the basis for future TCR gene-based immunotherapies that can be designed for the treatment of immunocompromised M. tuberculosis-infected patients.     

Quick identification of effective small interfering RNAs that inhibit the replication of coxsackievirus A16

Coxsackievirus A16 (CA16) is a major causative agent of hand, foot, and mouth disease (HFMD). It can cause myocarditis, pericarditis and fatal shock. There is no effective therapy against CA16. RNA interference (RNAi) is a powerful tool to silence gene expression. The small interfering RNA (siRNA) that induces RNA degradation has recently been used as an anti-virus agent to inhibit virus replication. In this study, we established the complete nucleotide sequence of CA16 strain Shzh05-1, and then compared the nucleotide sequences of Shzh05-1 with sequences of other CA16 strains in GenBank. We chose conserved regions between Shzh05-1 and the two other CA16 strains to design 30 siRNAs and construct siRNA-encoding plasmids. Thirteen siRNAs targeting conserved regions of the virus could effectively block replication of CA16 in cultured cells. Combination transfection of these 13 effective siRNAs could also produce a high inhibitory effect. These strategies and results suggest that RNAi has potential therapeutic use for suppression of CA16 infection.     

中国流行的麻疹病毒基因型和亚型趋势分析

目的分析中国（未包括香港、澳门特别行政区和台湾地区）1993～2006年本土麻疹病毒基因型和基因亚型的流行趋势。方法依据全国麻疹实验室网络监测数据库、中国疾病预防控制中心病毒病预防控制所国家麻疹实验室病毒学监测数据库,分析中国麻疹病毒分子流行病学资料。结果1993～2006年,从29个省（自治区、直辖市,下同）分离到748株麻疹病毒,其中743株为H1基因型,1株为H2基因型,1株为A基因型,3株为疫苗相关A基因型。在H1基因型中,684株为H1a基因亚型,50株为H1b基因亚型,9株为H1c基因亚型。从29个省分离到H1a基因亚型（西藏、湖北省未开展）,H1b基因亚型只从10个省分离到,H1c基因亚型在1993～1994年从4个省分离到。自2000年以来,H1a基因亚型逐年成为优势流行亚型,并呈上升趋势;H1b基因亚型逐年转为弱势,其传播于2006年被阻断;而H1c基因亚型的流行自1995年已经消失。结论通过对1993～2006年中国29个省流行的麻疹病毒分子流行病学的系统研究,阐明了在麻疹控制和加速控制阶段中国流行的麻疹野病毒的基因变异规律,以及病毒基因型别在地域和年代上的分布,证实H1基因型是中国近14年麻疹病毒流行的绝对优势本土基因型,其中H1a逐渐成为中国近几年流行的绝对优势基因亚型。