A new approach for selective rat endolymphatic sac epithelium collection to obtain pure specific RNA

The endolymphatic sac (ES) is an organ that is located in the temporal bone. Its anatomical location makes ES tissue collection without any contamination very difficult, and sometimes accurate molecular analyses of the ES are prevented due to this matter. In the present study, a new selective ES epithelial tissue collection method was attempted using laser capture microdissection to obtain pure ES RNA without any contamination. The validity of this method was demonstrated by RT-PCR with three specific primer pairs against osteocalcin, calponin H1, and NKCC2, which are specific proteins in bone, smooth muscle, and kidney/ES cells, respectively. From the RT-PCR results, the high specificity and sufficient sensitivity of the new method was indicated. It is considered that the new method is optimal for ES collection without contamination and it will be able to contribute to future analyses of the ES.     

DGGE技术在动物胃肠道微生物研究中的应用

变性梯度凝胶电泳(DGGE)是通过聚丙烯酰胺凝胶中变性剂浓度梯度的不同,将序列不同的DNA分开。目前,该技术已广泛应用于瘤胃微生物、肠道微生物等多样性研究。综述了变性梯度凝胶电泳技术的基本原理、优缺点及其在动物营养中的应用。     

太白山栎属树种气孔特征沿海拔梯度的变化规律

气孔是植物与外界环境进行水分和气体交换的主要通道,调节植物碳同化和水分散失的平衡关系,在一定程度上反映植物对外界环境变化的适应。沿太白山北坡1100—2300 m海拔,测定4种栎属树种的气孔性状,分析气孔性状沿海拔的变化规律和其对环境因子的响应。结果表明:(1)气孔密度与气孔长度间的负相关在4个树种间均显著存在(P0.05);除栓皮栎(Quercus variabilis)外,气孔密度与潜在气孔导度指数的正相关关系均达显著水平;而气孔宽度与气孔长度之间只在栓皮栎和锐齿栎(Q. aliena var. acuteserrata)达到显著水平。(2)栓皮栎和槲栎(Q. aliena)的气孔长度和宽度随海拔升高而下降,气孔密度、潜在气孔导度指数增加,辽东栎(Q. wutaishansea)变化形式则相反;锐齿栎气孔宽度减小,其余性状沿海拔呈单峰变化,在约1600 m处气孔长度达到最小值,气孔密度和潜在气孔导度指数达到最大值。(3)与土壤因子相比,气孔性状主要受气候因素的影响。潜在气孔导度指数与大气温度、空气湿度成极显著正相关(P0.01),与降水量显著负相关(P0.05)。其中,空气相对湿度是影响潜在气孔导度指数的主要因素,能够解释气孔变异的22.9%。本研究结果对于深入认识秦岭太白山地区栎属树种对环境变化的响应和适应提供理论证据。     

猪瘟病毒NS3基因克隆、原核表达及间接ELISA方法初步建立

采用PCR方法从携带猪瘟病毒兔化弱毒(Hog cholera lapinized virus,HCLV)全长基因组cDNA的质粒pPOHCLV中扩增到长度为2000bp左右NS3基因序列,并将其克隆至原核表达载体pET-32a(+),构建成重组原核表达载体pETNS3。将pETNS3在大肠杆菌Rosetta(DE3)中进行优化表达,SDS-PAGE分析重组蛋白NS3主要以包涵体形式表达,分子大小约95kD。Western Blotting分析表明重组蛋白NS3具有免疫原性。采用Ni+亲和层析方法纯化得到重组蛋白NS3(90%)。以纯化的重组蛋白NS3为抗原初步建立了检测CSFVNS3抗体的间接ELISA方法,检测221份不同猪群和年龄猪的血清样品。检测结果与IDEXX公司CSFV-Ab检测试剂盒检测结果进行对比,阳性符合率为83.33%,阴性符合率为89.38%,总符合率为86.43%。30份存在差异的血清样品用间接免疫荧光法(Indirect immunofluorescence assay,IFA)进行检测,结果显示IFA检测结果与NS3间接ELISA和IDEXX公司CSFV-Ab检测试剂盒符合率分别为56.67%和43.33%。     

Factor Structure of the Japanese Version of the Edinburgh Postnatal Depression Scale in the Postpartum Period

Background

The Edinburgh Postnatal Depression Scale (EPDS) is a widely used screening tool for postpartum depression (PPD). Although the reliability and validity of EPDS in Japanese has been confirmed and the prevalence of PPD is found to be about the same as Western countries, the factor structure of the Japanese version of EPDS has not been elucidated yet.

Methods

690 Japanese mothers completed all items of the EPDS at 1 month postpartum. We divided them randomly into two sample sets. The first sample set (n = 345) was used for exploratory factor analysis, and the second sample set was used (n = 345) for confirmatory factor analysis.

Results

The result of exploratory factor analysis indicated a three-factor model consisting of anxiety, depression and anhedonia. The results of confirmatory factor analysis suggested that the anxiety and anhedonia factors existed for EPDS in a sample of Japanese women at 1 month postpartum. The depression factor varies by the models of acceptable fit.

Conclusions

We examined EPDS scores. As a result, “anxiety” and “anhedonia” exist for EPDS among postpartum women in Japan as already reported in Western countries. Cross-cultural research is needed for future research.     

鸭绿江口湿地鸻鹬类停歇地的生物生态研究

鸭绿江口湿地是鸻鹬类在东亚一澳大利亚北迁路线上的最重要停歇地,潮间带上的双壳类、腹足类、多毛类等底栖动物为鸻鹬类提供了能量保障.2010年3月-2011年6月对鸭绿江口潮间带的生物生态进行了调查研究.研究结果表明,生物群落结构相对简单,主要以双壳类、腹足类和多毛类为主,优势种演替明显,系统具有低多样性低密度的特点.鸻鹬类能量补充来源相对匮乏,饵料生物量的更新速度较慢,所提供的能值也相对较低,江户明樱蛤、青蛤(幼体)和长吻沙蚕是鸻鹬类的主要食物来源.鸻鹬类主要集中在低潮带下区觅食,在北迁高峰期对低潮带下区饵料生物影响较显著,尤其对江户明樱蛤丰度影响最明显.泥螺作为优势种,生态位最宽,分布于整个调查断面和潮带,但因体表分泌一种毒性粘液而不被鸻鹬类取食.饵料生物的种群补充能力较强,在鸻鹬类迁徙高峰期之后,饵料丰度和生物量又会恢复到正常水平.虽然目前人类对鸻鹬类的威胁显现较小,但使人类一生态系统一滨鸟之间持续和谐统一,必须综合考量鸭绿江口湿地包括人类在内的生态系统各关键组分之间的生态关联,兼顾生态系统的完整性和人类社会经济发展的可持续性.     

Gram Stains: A Resource for Retrospective Analysis of Bacterial Pathogens in Clinical Studies

We demonstrate the feasibility of using qPCR on DNA extracted from vaginal Gram stain slides to estimate the presence and relative abundance of specific bacterial pathogens. We first tested Gram stained slides spiked with a mix of 10⁸ cfu/ml of Escherichia coli and 10⁵ cfu/ml of Lactobacillus acidophilus. Primers were designed for amplification of total and species-specific bacterial DNA based on 16S ribosomal gene regions. Sample DNA was pre-amplified with nearly full length 16S rDNA ribosomal gene fragment, followed by quantitative PCR with genera and species-specific 16S rDNA primers. Pre-amplification PCR increased the bacterial amounts; relative proportions of Escherichia coli and Lactobacillus recovered from spiked slides remained unchanged. We applied this method to forty two archived Gram stained slides available from a clinical trial of cerclage in pregnant women at high risk of preterm birth. We found a high correlation between Nugent scores based on bacterial morphology of Lactobacillus, Gardenerella and Mobiluncus and amounts of quantitative PCR estimated genus specific DNA (rrn copies) from Gram stained slides. Testing of a convenience sample of eight paired vaginal swabs and Gram stains freshly collected from healthy women found similar qPCR generated estimates of Lactobacillus proportions from Gram stained slides and vaginal swabs. Archived Gram stained slides collected from large scale epidemiologic and clinical studies represent a valuable, untapped resource for research on the composition of bacterial communities that colonize human mucosal surfaces.     

熔盐热裂解生物质制生物油

为探讨热裂解条件对熔盐中生物质热裂解制生物油的影响,在自行设计的反应器中,以摩尔比为7∶6的ZnCl2-KCl混合熔盐作为热裂解的热载体、催化剂和分散剂,考察了500 ℃时添加的金属盐和生物质原料的影响,并采用气相色谱-质谱仪 (GC-MS) 对生物油的主要组成进行了分析。结果表明：添加的金属盐显著影响热裂解产物得率,稀土金属盐显著提高生物油得率,降低生物油的含水率,添加摩尔分数为5.0％ LaCl3时生物油得率为32.0％,含水率为61.5％;水稻秸秆热裂解的生物油和焦炭得率较高,稻壳热裂解的气体得率较高;金属添加盐对生物油组成有较强的选择性,LiCl和FeCl2对生物质向小分子裂解具有较强的催化作用,而CrCl3、CaCl2和LaCl3对生物油二次裂解具有抑制作用。研究结果为熔盐热裂解生物质制生物油提供了参考。     

Subacute SARS-CoV-2 replication can be controlled in the absence of CD8+ T cells in cynomolgus macaques

SARS-CoV-2 infection presents clinical manifestations ranging from asymptomatic to fatal respiratory failure. Despite the induction of functional SARS-CoV-2-specific CD8⁺ T-cell responses in convalescent individuals, the role of virus-specific CD8⁺ T-cell responses in the control of SARS-CoV-2 replication remains unknown. In the present study, we show that subacute SARS-CoV-2 replication can be controlled in the absence of CD8⁺ T cells in cynomolgus macaques. Eight macaques were intranasally inoculated with 10⁵ or 10⁶ TCID₅₀ of SARS-CoV-2, and three of the eight macaques were treated with a monoclonal anti-CD8 antibody on days 5 and 7 post-infection. In these three macaques, CD8⁺ T cells were undetectable on day 7 and thereafter, while virus-specific CD8⁺ T-cell responses were induced in the remaining five untreated animals. Viral RNA was detected in nasopharyngeal swabs for 10–17 days post-infection in all macaques, and the kinetics of viral RNA levels in pharyngeal swabs and plasma neutralizing antibody titers were comparable between the anti-CD8 antibody treated and untreated animals. SARS-CoV-2 RNA was detected in the pharyngeal mucosa and/or retropharyngeal lymph node obtained at necropsy on day 21 in two of the untreated group but undetectable in all macaques treated with anti-CD8 antibody. CD8⁺ T-cell responses may contribute to viral control in SARS-CoV-2 infection, but our results indicate possible containment of subacute viral replication in the absence of CD8⁺ T cells, implying that CD8⁺ T-cell dysfunction may not solely lead to viral control failure.