1999～2005年我国婴幼儿人杯状病毒腹泻研究

人杯状病毒(HuCV)是世界范围内急性腹泻的重要病原。此文收集我国长春、北京、河北卢龙、兰州、昆明等13个地区1999-2005年5岁以下腹泻患儿检测轮状病毒为阴性的粪便标本4426份,用ELISA和RT-PCR方法检测HuCV,结果表明HuCV检测阳性率为19%(8.3%-38.6%)。对其中151株HuCV PCR产物测序进行核苷酸序列比对构建的系统发生树表明,我国流行的HuCV以诺如病毒(NV)为主(146/151,占96.7%),其中绝大多数为GGⅡ/4基因型(99/146),其它依次为GGⅡ/3(22/146)、GGⅡ/5(8/146)、GGⅡ/6(2/146)、GGⅡ/7(2/146)、GGⅡ/8(2/146)和GGⅠ/2(2/146),札如病毒(SV)共5株,均属SGⅡ。此外有9株NV GGⅡ遗传组毒株,尚不能归入现有基因型,可能为我国特有的新基因型,表明我国流行的HuCV毒株存在很高的遗传多样性。我国婴幼儿HuCV腹泻全年都有发生,但秋冬季(10月-次年1月)有一个发病高峰,病例以6-17月龄组最多,至3岁时超过96%的儿童都感染过HuCV。对我国流行的HuCV不同毒株的地区分布,不同年度HuCV检测阳性率的变化趋势进行了讨论。     

昆明地区儿童感染的GⅡ型诺如病毒分子分型研究

了解昆明地区诺如病毒在儿童中的流行特征和分型特点.统计整理昆明地区哨点医院,2018年6月-2019年10月内的1588例通过荧光定量PCR鉴定为诺如病毒(Norovirus,NV)阳性的病例资料,包括检测时间、年龄及性别,分析流行病学特征.收集到其中荧光定量结果显示病毒相对含量较高的485份儿童腹泻标本,通过逆转录PCR方法成功获得107-ORF1和94-ORF2基因序列信息,进一步进行分子分型.昆明地区2018年11月开始,检出NV的病例逐步增加,至2019年1月,NV检出率开始降低.NV相关性腹泻的易感人群为3岁前幼儿,其中1岁以下患儿占40％,1岁～3岁患儿占56％,其余3岁～16岁患儿仅占4％.分子分型结果显示,流行株根据ORF1分为GⅡP16、GⅡP12、GⅡ31三种亚型,依据ORF2的结果,属于GⅡ.4、GⅡ.2、GⅡ.3个分支.Tajima中性检验预测RdRp(GⅡ.P16),RdRp(GⅡ.P31),VP1(GⅡ.3),VP1(GⅡ.3)的 D 值分别为-2.03,-1.51,0.14,-1.13,其中大部分D值小于0.其中VP1(GⅡ.3)的D值为正值,有别于其他大部分预测结果,原因可能是样本量不足,需要在未来扩大样本量开展研究.NV对儿童的感染率在各年龄组间存在差异,在3岁以下儿童感染NV患病率较高.病毒呈季节性流行,主要集中在11月到次年2月.针对儿童患者,昆明地区同时流行3种不同基因型病毒株,优势流行株为GⅡ.P31-GⅡ.4.对突变频率较高的样本进行分析,其基因进化不遵循中性模型,需要进一步对病毒间基因重组进行分析.     

昆明婴幼儿腹泻的轮状病毒分子基因特征研究

目的了解昆明婴幼儿腹泻中轮状病毒感染情况。方法收集昆明医学院第一附属医院儿科2004年10-12月住院的腹泻的患儿粪便标本60份,采用聚丙烯酰胺凝胶电泳（PAGE）法和RT—PCR法进行轮状病毒分型。结果60份粪便标本中,29份检测到A组轮状病毒RNA基因,阳性检出率为48.3％,未发现B组及C组轮状病毒。其中RNA长型有29份（100％）,未发现短型和混合型。对29份有明确编号的轮状病毒阳性标本来源的患儿分析显示,平均发病年龄10.5个月。29份标本中,有20份可用RT—PCR分型,均为G3型,未发现其他型。结论A组轮状病毒是昆明地区5岁以下婴幼儿腹泻病的主要病原,3月龄-2岁婴幼儿是轮状病毒的易感人群,以冬季10月份至12月份为流行高峰,基因组以长型为主,血清型为G3型。     

胶体金法与RT-PCR法测定A群轮状病毒及G血清型分型

目的了解婴幼儿A群轮状病毒腹泻的流行病学特征。方法收集浙江省苍南县人民医院2009年1-12月份的婴幼儿腹泻粪便标本,采用胶体金免疫层析法和逆转录-聚合酶链反应法进行轮状病毒抗原检测和血清型分型,分析G血清型分型。结果 828份婴幼儿腹泻粪便轮状病毒阳性率为33.45%。在轮状病毒腹泻患儿中,1岁以内占49.82%,2岁以内占89.89%。本地区轮状病毒腹泻呈现季节高峰,11月至次年1月为轮状病毒腹泻流行期。毒株分型显示G3型为流行优势株（51.6%）,其次是G1型（26.6%）;另有13.7%为混合感染,包括G1＋G3型（10.5%）、G2＋G3型（2.4%）和G1＋G9型（0.8%）。结论 2009年浙江省苍南县婴幼儿轮状病毒腹泻的主要血清型是G3和G1,G3为优势毒株。 更多还原     

大连地区食源性腹泻病例中诺如病毒基因特征分析

目的了解大连地区食源性腹泻病例中诺如病毒的基因特征。方法采用荧光定量RT-PCR对2016年大连市食源性疾病监测哨点医院采集的1 900份粪便标本进行诺如病毒核酸检测,用逆转录PCR对阳性毒株的ORF1-ORF2连接区扩增并测序,分析其基因亚型和同源性。结果 1 900份标本中,检出诺如病毒核酸阳性25份,阳性率1.32%,其中GⅠ型阳性3份,GⅡ型阳性19份,GⅠ型和GⅡ型均阳性3份。26株病毒基因序列比对,发现3株为GⅠ.3,2株为GⅠ.6,9株为GⅡ.17,5株为GⅡ.4,2株为GⅡ.2,GⅡ.3、GⅡ.6、GⅡ.13、GⅡ.14、GⅡ.15各1株。结论大连地区食源性腹泻病例中诺如病毒呈基因多样性,2016年流行优势株为GⅡ.17。GⅡ.2、GⅡ.3、GⅡ.6、GⅡ.13、GⅡ.14、GⅡ.15在大连地区首次检出。     

冬季急性下呼吸道感染住院儿童病原学分析及临床流行病学特点

目的了解冬季儿童急性下呼吸道感染病原谱及临床流行病学特征,为临床抗感染及病原检测提供依据。方法对我院2006年12月～2007年2月急性下呼吸道感染住院患儿采用一次性无菌吸痰管经鼻腔插入7～8cm,达到咽部以下负压吸取1～2ml深部鼻咽分泌液送细菌培养,并对呼吸道合胞病毒(RSV),腺病毒(ADV),A、B型流感病毒(IFV),1、2及3型副流感病毒(PIV)等7种常见呼吸道病毒抗原进行检测及运用荧光定量聚合酶链反应(PCR)技术检测标本中支原体和衣原体DNA。结果①381份下呼吸道感染儿童痰标本中细菌培养阳性81份,病毒检测阳性133份,支原体和衣原体阳性分别12份与6份,混合感染标本44份,总标本病原学检出率为50.66%(193/381)。②RSV阳性标本112份,为最重要的感染病原,连续3个月RSV检出率均在30%左右,6月龄以下儿童占61.61%,2岁以下儿童占86.61%,阳性标本中78.57%的患儿有喘息表现。③大肠埃希菌(16株)、肺炎链球菌(14株)、肺炎克雷伯菌及金黄色葡萄球菌(各10株)、卡他莫拉菌布兰汉亚种(8株)、流感嗜血杆菌和副流感嗜血杆菌(各6株)表现为主要的致病菌。结论RSV感然仍为儿童冬季急性下呼吸道感染最主要的病原,尤其在2岁以下儿童,且易表现为喘息发作。仍有40%以上感染病原未明,儿童急性下呼吸道感染病原谱需进一步完善。     

浙江省2019年儿童腺病毒肺炎流行病学特征分析

为了解浙江地区腺病毒肺炎的流行病学和病原学特征,本研究统计分析了2019年1月至2019年12月浙江大学医学院附属儿童医院腺病毒肺炎患儿的基本临床资料;并前瞻性的通过聚合酶链式反应(PCR)随机对部分的腺病毒阳性的肺炎患儿咽拭子进行基因扩增、测序和分型鉴定;进而构建系统发育树分析其核苷酸序列进化情况。本研究共检测咽拭子标本19650份,其中腺病毒阳性标本有4032份,腺病毒检出率为20.5%;春季和夏季腺病毒肺炎的患病率相对较高,患儿年龄主要在1~7岁。本研究所检测的99株腺病毒阳性标本经与GenBank数据库比对均为HAdV-3,通过Hexon基因全长系统进化分析得出,所检出的HAdV-3腺病毒均为Clade2进化分支。2019年浙江地区存在儿童HAdV-3肺炎的暴发流行,该病毒株未发生大的变异,均为Clade2进化分支。1~7岁的儿童为主要的易感人群。     

宁夏地区2019-2020年诺如病毒所致感染性腹泻流行特征和病原学分析

了解宁夏地区感染性腹泻患者中诺如病毒的流行特征和基因进化规律，为该地区诺如病毒所致腹泻防控策略的制定提供科学依据。在宁夏自治区5个市的15家哨点医院开展腹泻症状监测，收集患者粪便标本和相关信息并采用Real-time RT-PCR方法进行诺如病毒初筛检测，阳性标本扩增其聚合酶（RdRp）-衣壳蛋白（Capsid）区基因，扩增产物测序后使用Sequencher 4.1.4软件进行序列拼接和编辑，并用MEGA-X、DNASTAR生物软件进行序列比对、系统进化分析以及同源性分析，应用SPSS 25.0软件进行相关统计学分析。结果显示2019-2020年共收集感染性腹泻患者粪便标本2 358份，诺如病毒检出率为13.44%(317/2 358)。主要为GⅡ基因群（285/317），其中，0～2岁年龄组阳性率最高，为18.43%(188/1 020);60～70岁年龄组阳性率最低，为3.36%(4/119)，各年龄组阳性率差异有统计学意义（P<0.05）。不同地区、年份、季节间阳性率比较，差异有统计学意义。GⅠ基因群（32/2 358）以GⅠ.P13/GⅠ.3(75.0%)为流行优势株，G...     

北京地区住院患儿WU多瘤病毒感染的流行病学研究

自2007年Gaynor A M等人通过高通量测序在肺炎患儿呼吸道样本中发现了WU多瘤病毒(Washington University polyomavirus,WUPyV)以来,WUPyV在世界各地被广泛检出。为了解北京地区急性呼吸道感染住院儿童中WUPyV感染情况及其临床特征,收集北京地区2017年4月至2018年3月共1 276份呼吸道感染住院患儿的鼻咽抽吸物样本,使用real time PCR方法对样本进行WUPyV检测,同时对WUPyV阳性样本进行17种常见呼吸道病毒筛查。共检出WUPyV阳性样本76份(5.96%,76/1 276),4岁以下儿童居多(92.11%,70/76);WUPyV感染全年可见,无显著季节性;多伴随其他呼吸道病毒混合感染(60.53%,46/76),最常见混合感染为鼻病毒和A型流感病毒;WUPyV单一感染者与混合感染者病毒载量无显著性差异,临床诊断和表现基本一致;WUPyV感染患儿的常见诊断为支气管炎(68.42%,52/76)和肺炎(30.26%,23/76);临床症状主要表现为高热、咳嗽、咳痰。研究结果提示WUPyV是北京地区急性呼吸道感染住院患儿呼吸道样本中常见病毒之一,多见于4岁以下儿童。     

我国九省区2006年札如病毒流行状况及基因序列分析

为了研究我国札如病毒(Sapovirus,SV)的流行情况及变异特点,收集了2006年2月至2007年1月安徽省、福建省、海南省、河北省、河南省等9个地区5岁以下腹泻患儿的粪便标本共1 110份,应用逆转录-聚合酶链反应(RT-PCR)对札如病毒进行检测,结果表明,札如病毒阳性率为0.9%。对检测到的全部10株札如病毒进一步进行系统进化分析,表明这10株札如病毒属于三个基因型:GI/1、GI/3和GII/3。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.     

2018年中国植物科学若干领域重要研究进展

2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。     

2018年中国植物科学若干领域重要研究进展

2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。     

我国葫芦科植物离体培养研究进展

葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义。综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望。     

2017年中国植物科学若干领域重要研究进展

2017年中国植物科学继续保持高速发展态势, 重大成果频出, 具体表现在中国植物学家在国际顶级学术期刊发表的文章数量平稳上升。中国植物科学领域的研究工作者成果精彩纷呈, 如新型广谱抗病机制的发现、水稻广谱抗病遗传基础及机制和疫霉菌诱发病害成灾机制研究等。2017年中国生命科学领域十大进展评选中, 有两项植物科学领域的研究成果入选。水稻生物学、进化与基因组学和激素生物学等领域学科发展突出。另外, 值得一提的是, 长期从事高等植物与代谢途径调控分子网络研究和水稻品种设计育种的李家洋院士的研究成果“水稻高产优质性状形成的分子机理及品种设计”荣获2017年国家自然科学一等奖。这一具有重大国际影响的开创性贡献标志着中国植物科学在该领域的国际科学前沿居于引领和卓越地位。该文对2017年中国本土科学家在植物科学若干领域取得的重要研究成果进行了系统梳理, 旨在全面追踪和报道当前中国植物科学领域发展的最新前沿动态, 与广大读者共同分享我国科学家所取得的辉煌成就。     

我国葫芦科植物离体培养研究进展

葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义.综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望.     

Changes in aquatic vegetation in Rhine floodplain streams in Alsace in relation to disturbance

Abstract. Changes are described in aquatic vegetation in oligotrophic, groundwater-fed Rhine floodplain streams in Alsace (eastern France), resulting from disturbance. Disturbance factors include changes in nutrients, either permanent ones - effluent from a waste water treatment plant or trout hatcheries - or periodic ones: flooding. Regular inputs of high levels of phosphate and ammonia modified the macrophyte vegetation in these streams. The floristic composition, which was characteristic of oligotrophic waters upstream of the eutrophicated sector, changed to that of a eutrophic situation as originally found downstream. Periodic disturbance by floods which normally occur once a year, irregularly eutrophicates the small streams, causing the development of a mixture of eutrophic and oligotrophic species. Six macrophyte communities are distinguished, indicating different trophic levels. The aquatic vegetation is adapted to the variations of phosphate and ammonia levels. Hence, aquatic macrophytes can be used as bio-indicators of fluctuations in water nutrient levels in relation to the type of disturbance.     

Morphine-potentiated platelet aggregation in in vitro and platelet plug formation in in vivo experiments

The detailed mechanisms underlying morphine-signaling pathways in platelets remain obscure. Therefore, we systematically examined the influence of morphine on washed human platelets. In this study, washed human platelet suspensions were used for in vitro studies. Furthermore, platelet thrombus formation induced by irradiation of mesenteric venules with filtered light in mice pretreated with fluorescein sodium was used for an in vivo thrombotic study. Morphine concentration dependently (0.6, 1, and 5 microM) potentiated platelet aggregation and the ATP release reaction stimulated by agonists (i.e., collagen and U46619) in washed human platelets. Yohimbine (0.1 microM), a specific alpha(2)-adrenoceptor antagonist, markedly abolished the potentiation of morphine in platelet aggregation stimulated by agonists. Morphine also potentiated phosphoinositide breakdown and intracellular Ca(2+) mobilization in human platelets stimulated by collagen (1 microg/ml). Moreover, morphine (0.6-5 microM) markedly inhibited prostaglandin E(1) (10 microM)-induced cyclic AMP formation in human platelets, while yohimbine (0.1 microM) significantly reversed the inhibition of cyclic AMP by morphine (0.6 and 1 microM) in this study. The thrombin-evoked increase in pH(i) was markedly potentiated in the presence of morphine (1 and 5 microM). Morphine (2 and 5 mg/g) significantly shortened the time require to induce platelet plug formation in mesenteric venules. We concluded that morphine may exert its potentiation in platelet aggregation by binding to alpha(2)-adrenoceptors in human platelets, with a resulting inhibition of adenylate cyclase, thereby reducing intracellular cyclic AMP formation followed by increased activation of phospholipase C and the Na(+)/H(+) exchanger. This leads to increased intracellular Ca(2+) mobilization, and finally potentiation of platelet aggregation and of the ATP release reaction.     

Apoptosis in experimental myocardial infarction in situ and in the perfused heart in vitro

We report the appearance of apoptotic cells in experimental myocardial infarction (rabbit heart) in in situ and in vitro preparations. Apoptosis was recognized by intravital staining with Hoechst 33342 (Ho342), by nick-end labeling (TUNEL) and by DNA laddering. A steady rise in the relative number of apoptotic cardiomyocytes (apoptotic index) was noted in in situ preparations. Apoptosis was first noted 6 h after the onset of ischemia with its highest value occurring after 72 h. Apoptotic nuclei were absent in remote areas of the left and right ventricles. Apoptotic nuclei within the infarcted area showed diminished intensity of Ho342 fluorescence. Three days after ischemia, a border zone adjacent to the infarcted area consisting of apoptotic macrophages was recognized. A novel finding was the appearance of apoptotic cardiomyocytes in the isolated perfused ischemic heart. Occurring as early as 50 min after the onset of ischemia, a high apoptotic index was present adjacent to the ligature placed around the coronary artery. This observation provides the opportunity to selectively examine factors leading to apoptosis in the ischemic heart under controlled experimental conditions.