SpltMNPV日本分离株gp41的克隆表达及gp41和ph的进化分析

从斜纹夜蛾核型多角体病毒(Spodopteralitura multicapsid nucleopolyhedrovirus,SpltMNPV)日本分离株(C3)基因组中克隆了gp41基因.该基因编码区含993bp核苷酸,编码分子量为36.9kDa的多肽.将该基因克隆至原核表达载体pET28a,经IPTG诱导后在大肠杆菌BL21(DE3)中获得了表达.应用CLUSTAL程序分析表明,SpltMNPV日本株(C3)gp41的核苷酸序列和氨基酸序列与SpltMNPV中国G2株相似性最高,均达99.9%.用MEGA分别构建了基于gp41和ph的聚类分析图和分子进化树,发现它们具有相似的拓扑结构.将这两个基因序列结合在一起构建进化树,该树的结构与基于gp41的进化树相似.突变率分析显示gp41的突变率高于ph,这意味着在杆状病毒进化过程中,gp41和ph面临不同的选择压力.     

Efficient mucosal vaccination mediated by the neonatal Fc receptor

Almost all infectious diseases are initiated at mucosal surfaces, yet intramuscular or subcutaneous vaccination usually provides only minimal protection at sites of infection owing to suboptimal activation of the mucosal immune system. The neonatal Fc receptor (FcRn) mediates the transport of IgG across polarized epithelial cells lining mucosal surfaces. We mimicked this process by fusing a model antigen, herpes simplex virus type-2 (HSV-2) glycoprotein gD, to an IgG Fc fragment. Intranasal immunization, together with the adjuvant CpG, completely protected wild-type, but not FcRn knockout, mice after intravaginal challenge with virulent HSV-2 186. This immunization strategy induced efficient mucosal and systemic antibody, B- and T-cell immune responses, with stable protection for at least 6 months after vaccination in most of the immunized animals. The FcRn-IgG transcellular transport pathway may provide a general delivery route for subunit vaccines against many mucosal pathogens.     

人X染色体间期细胞遗传学研究

应用人X染色体α卫星DNA探针进行X染色体正常或异常个体的外周血淋巴细胞染色体和间期核的原位杂交,在R显带的中期分裂相上,绝大部分杂交颂粒位于X染色体着丝粒区(p11→q11);在间期核内则显现与X染色体数相一致的银颗粒簇,其中相当部分位于核边缘区。实验结果表明,用原位杂交来检测X染色体数目,比记数Barr小体的方法可靠。本文还就α卫星DNA探针在间期细胞遗传学方面广泛的应用做了讨论。     

Nicotianamine,a Novel Enhancer of Rice Iron Bioavailability to Humans

Background

Polished rice is a staple food for over 50% of the world''s population, but contains little bioavailable iron (Fe) to meet human needs. Thus, biofortifying the rice grain with novel promoters or enhancers of Fe utilization would be one of the most effective strategies to prevent the high prevalence of Fe deficiency and iron deficiency anemia in the developing world.

Methodology/Principal Findings

We transformed an elite rice line cultivated in Southern China with the rice nicotianamine synthase gene (OsNAS1) fused to a rice glutelin promoter. Endosperm overexpression of OsNAS1 resulted in a significant increase in nicotianamine (NA) concentrations in both unpolished and polished grain. Bioavailability of Fe from the high NA grain, as measured by ferritin synthesis in an in vitro Caco-2 cell model that simulates the human digestive system, was twice as much as that of the control line. When added at 1∶1 molar ratio to ferrous Fe in the cell system, NA was twice as effective when compared to ascorbic acid (one of the most potent known enhancers of Fe bioavailability) in promoting more ferritin synthesis.

Conclusions

Our data demonstrated that NA is a novel and effective promoter of iron utilization. Biofortifying polished rice with this compound has great potential in combating global human iron deficiency in people dependent on rice for their sustenance.     

‘Green tides’ are overwhelming the coastline of our blue planet: taking the world’s largest example

A broad spectrum of events that come under the category of green tide are recognized world-wide as a response to elevated levels of seawater nutrients in coastal areas. Green tides involve a wide diversity of sites, macroalgal species, consequences, and possible causes. Here we review the effect of natural and man-induced environmental fluctuations on the frequency and apparent spread of green tides. This article highlights the need for interdisciplinary research aimed at shedding light on the basic mechanisms governing the occurrence and succession of green algae in coastal seas. This will result in more effective management and mitigation of the effects of green tides, thus safeguarding the intrinsic and commercial value of coastal marine ecosystems.     

Sunitinib Reverse Multidrug Resistance in Gastric Cancer Cells by Modulating Stat3 and Inhibiting P-gp Function

Sunitinib, a small-molecule multi-targeted tyrosine kinase inhibitor, has been applied in phase II clinical trial as second-line treatment for advanced gastric cancer. In this study, we determined the effect of Sunitinib on the multidrug resistance in gastric cancer cells selected by vincristine. Our results showed that Sunitinib significantly enhanced the cytotoxicity of adriamycin, vincristine, etoposide, 5-Fluorouracil, and cisplatin in multidrug-resistant gastric cancer cells (SGC7901/VCR). Sunitinib significantly increased the intracellular accumulation and retention of rhodamine 123 in the SGC7901/VCR cells. However, Sunitinib, at a concentration that reverses MDR, had no significant effect on P-gp protein or mRNA expression levels. In addition, the present study revealed that Sunitinib inhibited Stat3 and down-regulated Bcl-2 in SGC7901/VCR cells, which might also contribute to the reversal of MDR. In conclusion, Sunitinib reverses multidrug resistance in gastric cancer cells by inhibiting P-gp transporter function and modulating Stat3 and Bcl-2. Further study with Sunitinib may be helpful for developing combination therapeutic strategy or circumventing gastric cancer MDR to other conventional anti-cancer drugs.     

Precise Reconstruction of Veins and Bile Ducts in Rat Liver Transplantation

Rat orthotopic liver transplantation (ROLT) remains a technically demanding procedure, especially regarding the reconstruction of the suprahepatic vena cava (SHVC). In this study, a new microsuture technique was developed for anastomosis of the SHVC, and a special single-groove cuff and blade-cut stent were introduced. With these modified techniques, we aimed to make a precise anastomosis of the SHVC and to provide optimal cuffs and stents for the reconstruction of the veins and bile ducts. According to different microsuture techniques for the SHVC and different types of cuffs and stents, three ROLT groups were created to compare the operation times and prognoses. Sham operations were performed as controls in the fourth group. The time expenditures with each step were compared among the transplantation groups. Biochemical parameters were tested at the end of a 1-month observation period. The short- and long-term survival rates of the transplantation groups were recorded and compared. Our new microsuture technique was faster than the conventional continuous suture technique for SHVC anastomosis (P < 0.05). The use of a single-groove cuff for reconstruction of the portal vein and the infrahepatic vena cava shortened the anastomotic time (P < 0.05). The use of blade-cut stents resulted in fewer biliary complications and better survival over the short and long terms (P < 0.05). Our new microsuture technique and the single-groove cuffs proved to be a precise method for venous reconstruction which shortened the anhepatic time and the anastomotic time significantly. The blade-cut stents apparently reduced the incidence of biliary complications. In summary, with this precise microsuture technique and delicate cuffs and stents, excellent long-term survival can be achieved easily and stably for ROLT.     

栀子提取物ZG对单纯疱疹病毒1型细胞吸附的影响

采用负染技术,借助高倍电子显微镜观察栀子提取物ZG作用后,病毒颗粒及其病毒吸附蛋白(virus attach-ment protein,VAP)的变化,考察药物是否直接改变或破坏病毒包膜蛋白的结构,使其失去感染性;采用异硫氰酸荧光素(fluorescein isothiocyanate,FITC)标记病毒,以肝素钠为参照,借助冷却慢扫描电荷耦合器件荧光成象技术,用Aquacomos软件进行图象分析,以探讨栀子提取物ZG不同加药方式对HSV-1吸附量的影响。结果表明栀子提取物ZG对HSV-1包膜表面的VAP无直接破坏作用,不影响病毒对Hep-2细胞的感染性;先加入肝素钠再进行病毒吸附及肝素钠病毒同时加入培养细胞这两种用药方式可明显减少细胞表面病毒的吸附量;栀子提取物ZG各种不同加药方式均能阻止HSV-1对Hep-2细胞表面的吸附,使病毒吸附量减少。