High-yield production of recombinant virus-like particles of enterovirus 71 in Pichia pastoris and their protective efficacy against oral viral challenge in mice

Enterovirus 71 (EV71) is one of the major causative pathogens of hand, foot and mouth disease (HFMD), which is highly prevalent in the Asia-Pacific regions. Severe HFMD cases with neurological complications and even death are often associated with EV71 infections. However, no licensed EV71 vaccine is currently available. Recombinant virus-like particles (VLPs) of EV71 have been produced and shown to be a promising vaccine candidate in preclinical studies. However, the performance of current recombinant expression systems for EV71 VLP production remains unsatisfactory with regard to VLP yield and manufacturing procedure, and thus hinders further product development. In this study, we evaluated the expression of EV71 VLPs in Pichia pastoris and determined their protective efficacy in mouse models of EV71 infections. We showed that EV71 VLPs could be produced at high levels up to 4.9% of total soluble protein in transgenic P. pastoris yeast co-expressing P1 and 3CD proteins of EV71. The resulting yeast-produced VLPs potently induced neutralizing antibodies against homologous and heterologous EV71 strains in mice. More importantly, maternal immunization with VLPs protected neonatal mice in both intraperitoneal and oral challenge experiments. Collectively, these results demonstrated the success of simple, high-yield production of EV71 VLPs in transgenic P. pastoris, thus lifting the major roadblock in commercial development of VLP-based EV71 vaccines.     

中国1995－2012年双生子出生体重变化趋势分析

目的 描述分析中国双生子出生体重变化趋势。方法 使用中国双生子登记系统在中国8个省份收集的1995-2012年出生的双生子人群(共10 827对),采用病例回顾方法分析出生体重各指标情况和变化趋势。结果 调整性别、卵型、出生地区后,出生年份每推迟5年,双生子出生体重平均值降低0.01 kg(P=0.041).随着时间变化,双生子优势方出生体重、劣势方出生体重均不同程度地降低,出生体重相对差与出生体重不一致率在2007年以后有升高趋势。结论 1995-2012年中国双生子出生体重呈下降趋势,出生体重不一致率逐渐上升。考虑到出生体重不一致与某些不良健康结局的风险存在关联,应对双生子出生体重不一致予以重视。     

女性出生体重与2型糖尿病风险的跨代研究

目的 探索女性出生体重与T2DM的代际关联。方法 2012年11月至2013年1月对10 324名上海市有亲缘关系的2～4代女性开展横断面调查,通过问卷调查出生信息及T2DM史。将所有对象分成连续2代,共6 436对母女纳入分析。运用通径分析方法评估母代出生体重及T2DM患病状况对子代的影响;并采用中介效应分析方法分析子代出生体重是否为2代T2DM患病风险的中介因素。结果 2代人群的出生体重呈正相关,母代出生体重每增加1 kg,子代出生体重平均增加0.335 kg(95%CI:0.307～0.363).与无T2DM母亲的子代相比,患T2DM母亲的子代出生体重平均高0.066 kg(95%CI:0.025～0.107),患T2DM的风险增加3.173倍(95%CI:1.946～5.174).≥20岁研究对象中,调整年龄后,未见出生体重对成年期T2DM的影响。通径和中介分析显示,母代出生体重对子代出生体重的影响较大;子代出生体重高是母代患T2DM与子代患T2DM的中介因素,并减弱了二者关联的2.8%.结论 母代出生体重及T2DM状况对子代出生体重及成年后的T2DM风险有一定影响。     

Live porcine reproductive and respiratory syndrome virus vaccines: Current status and future direction

Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) was reported in the late 1980s. PRRS still is a huge economic concern to the global pig industry with a current annual loss estimated at one billion US dollars in North America alone. It has been 20 years since the first modified live-attenuated PRRSV vaccine (PRRSV-MLV) became commercially available. PRRSV-MLVs provide homologous protection and help in reducing shedding of heterologous viruses, but they do not completely protect pigs against heterologous field strains. There have been many advances in understanding the biology and ecology of PRRSV; however, the complexities of virus-host interaction and PRRSV vaccinology are not yet completely understood leaving a significant gap for improving breadth of immunity against diverse PRRS isolates. This review provides insights on immunization efforts using infectious PRRSV-based vaccines since the 1990s, beginning with live PRRSV immunization, development and commercialization of PRRSV-MLV, and strategies to overcome the deficiencies of PRRSV-MLV through use of replicating viral vectors expressing multiple PRRSV membrane proteins. Finally, powerful reverse genetics systems (infectious cDNA clones) generated from more than 20 PRRSV isolates of both genotypes 1 and 2 viruses have provided a great resource for exploring many innovative strategies to improve the safety and cross-protective efficacy of live PRRSV vaccines. Examples include vaccines with diminished ability to down-regulate the immune system, positive and negative marker vaccines, multivalent vaccines incorporating antigens from other porcine pathogens, vaccines that carry their own cytokine adjuvants, and chimeric vaccine viruses with the potential for broad cross-protection against heterologous strains. To combat this devastating pig disease in the future, evaluation and commercialization of such improved live PRRSV vaccines is a shared goal among PRRSV researchers, pork producers and biologics companies.     

中药清法对糖尿病足患者微循环障碍的疗效分析

目的探讨中药清法治疗糖尿病足患者微量白蛋白尿对微循环障碍疗效。方法 200例糖尿病足患者随机分为中西医治疗组和西医对照组,各100例。两组均采用相同的基础治疗。中西医治疗组予中药清法,药物组成: 穿心莲、蚤休、垂盆草、川乌、三七、冰片,100ml/袋,每次1袋,2次/d;西医对照组予西洛他唑100mg,1次/d,口服,且均行血生化、微量白蛋白尿及血液流变学的检测,比较治疗前后二组的变化。结果 用药前,两组患者的年龄、体质量、身高、BMI、收缩压、舒张压、TC、HDL-C、LDL-C、TG、BUN、Cr、UA、FPG、2hPG、MA、全血黏度低切、全血黏度中切、全血黏度高切、血浆黏度、血细胞比容、红细胞聚集指数和纤维蛋白原差异均无统计学意义(P＞0.05)。治疗后,两组患者的TC、TG、UA、FPG、MA、全血黏度低切、全血黏度中切、全血黏度高切、血浆黏度、血细胞比容、红细胞聚集指数和纤维蛋白原差异有统计学意义(P＜0.05),HDL-C、LDL-C、BUN、Cr、2hPG差异无统计学意义(P＞0.05)。此外,依据“脱疽”诊治疗效标准和糖尿病足坏疽疗效判定标准比较中西医治疗组与西医对照组的治疗结果,疗效差异有统计学意义(P＜0.01)。结论 中药清法通过治疗糖尿病足患者微量白蛋白尿和血液流变学,进而改善患者微循环障碍,促进伤口愈合,是值得推广的一种方法。     

The diffusion of autism spectrum disorder in Costa Rica: Evidence of information spread or environmental effects?

In the U.S., children with autism spectrum disorder (ASD) have been found to live in spatial clusters. Studies have suggested that the clustering is caused by social or environmental factors, but determining the cause of the clustering is difficult in the U.S. setting because of unmeasured variation in healthcare access and diagnostic practices. The present study explores the diffusion of ASD in a small setting in which the diagnosis is not widely publicised and there is no variation in healthcare access or diagnostic practices. Costa Rica provides universal healthcare and only has one diagnosing clinic for young children, and the diagnosis is relatively new and little known among clinicians and parents. In addition, the potential for mercury exposure from the source that has been associated with ASD is absent, and areas with high levels of air pollution are spatially concentrated. Focusing on all young children who underwent an ASD assessment from 2010 to 2013, we identify spatial clusters that suggest a mechanism that does not depend on information about ASD, healthcare access, diagnostic practices, or environmental toxicants. These findings provide details of the “contextual drivers” of the increasing worldwide prevalence of ASD.     

Epigenetic dimension of oxygen radical injury in spermatogonial epithelial cells

The present work reports a direct role of mitochondrial oxidative stress induced aberrant chromatin regulation, as a central phenomenon, to perturbed genomic integrity in the testicular milieu. Oxygen-radical injury following N-succinimidyl N-methylcarbamate treatment in mouse spermatogonial epithelial (GC-1 spg) cells induced functional derailment of mitochondrial machinery. Mitophagy resulted in marked inhibition of mitochondrial respiration and reduced mtDNA copy number. Impaired cell cycle progression along with altered H3K9me1, H4K20me3, H3, AcH3 and uH2A histone modifications were observed in the treated cells. Dense heterochromatin foci and aberrant expression of HP1α in nuclei of treated cells implied onset of senescence associated secretory phenotype mediated through nuclear accumulation of NF-κB. Neoplastic nature of daughter clones, emerged from senescent mother phenotypes was confirmed by cytogenetic instability, aberrant let-7a and let-7b miRNA expression and anchorage independent growth. Together, our results provide the first insights of redox-dependent epigenomic imbalance in spermatogonia, a previously unknown molecular paradigm.