No abstract

Genes of two iron-regulated outer membrane proteins of Vibrio parahaemolyticus zj2003, a pathogenic strain isolated from large yellow croaker (Pseudosciaena crocea), psuA and pvuA, were cloned and expressed as N-terminal His(6)-tagged proteins in Escherichia coli BL(21)(DE(3)). The recombinant fusion proteins were purified with nickel chelate affinity chromatography. To analyze the immunogenicity of the proteins, groups of large yellow croaker were immunized with the purified recombinant psuA, pvuA or both, by intraperitoneal injection. Antibody response was assessed by enzyme-linked immunosorbent assay. Titers to the recombinant proteins increased from log(2) 3.25 to log(2) 9.80, 4-8 weeks following immunization. The relative percent survival of the groups vaccinated with psuA, pvuA, or a combination of the two, reached 50%, 62.5% and 75%, respectively. Western blot analysis was carried out with the serum from unvaccinated survival fish after infection. Both recombinant proteins were detected, indicating that these two proteins of V. parahaemolyticus zj2003 were immunogenic and could produce synergistic effects during in vivo infection, and they might be considered as important components for developing an aquaculture vaccine against this pathogen.

Osteoporosis is a major public health problem for old people. Genetic factors are considered to be major contributors to the pathogenesis of postmenopausal osteoporosis. The vitamin D receptor (VDR) gene is a prominent candidate gene for the regulation of postmenopausal bone mass; however, despite extensive studies, controversy remains regarding its association with postmenopausal body mineral density (BMD) variation. In this study, a total of 260 healthy postmenopausal Chinese women were genotyped at the VDR ApaI locus using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Raw hip BMD was significantly associated with VDR ApaI polymorphism with and without adjusting for age (P=0.015 and 0.040, respectively). This genetic effect can explain 3.32% of hip BMD variation. However, the significant association vanished after correcting for both age and body mass index (BMI) (P=0.169). In addition, we observed a significant association between VDR ApaI polymorphism with unadjusted BMI (P=0.042) or BMI adjusted for age (P=0.049). The raw hip BMD was also found to be significantly correlated with BMI (r=0.517, P=0.0001), with BMI explaining 26.35% of the variation of hip BMD. All of these facts prompt us to conclude that the significant association between the VDR ApaI genotype and hip BMD may be modified by BMI in postmenopausal Chinese women. Our findings may partially explain the earlier inconsistent association results concerning the VDR gene and BMD, and highlight the importance of incorporating covariates such as BMI into osteoporosis association studies.

A plasmid DNA that encodes chicken interleukin-2 (pCI-ChIL-2-EGFP) was investigated for its distribution and expression after intramuscular (i.m.) injection in chickens. After the i.m. injection, serum distribution was detectable from 2 h post inoculation (p.i.), peaked at 8 h p.i., and disappeared at 7 days p.i. The plasmid DNA was also observed in several organs including heart, liver, lung, spleen, bursa and inoculated muscle at different time points, but at 19 days p.i. the plasmid DNA was not found in any organ except inoculated muscle. Fluorescence of enhanced green fluorescent protein (EGFP) was found in cytoplasm and nucleus of cultured Vero cells, chicken embryo fibroblasts and peripheral blood lymphocytes, which were transfected in vitro with the plasmid DNA or in vivo with Lipofectamine. The expression profile of the fusion gene (ChIL-2-EGFP) in vivo was measured by RT-PCR, ELISA and fluorescence microscopy. The EGFP expression was detected from 8 h p.i. to 14 days p.i. and peaked at 5 days p.i., when the number of EGFP-expression myocytes was about 5% in the injected site. These results demonstrate that intramuscular administration of plasmid DNA leads to widespread distribution and long-term expression in vivo.