2012-2015年广东省活禽市场外环境禽流感病毒污染状况研究

研究广东省活禽市场外环境禽流感病毒污染状况并及时发现人流感发病潜在的危险因素,为人流感防治提供科学参考依据。应用传染病技术监测平台信息管理系统数据,采用描述性流行病学方法分析各种亚型病毒感染的流行病学特征,研究2012-2015年广东省活禽市场外环境禽流感病毒污染。共采集检测广东省21个地市级样本33079份,FluA 总阳性率为24．23％,H5、H7和 H9型高致病性禽流感病毒阳性率分别为3．70％、3．89％和13．53％;除2012年阳性率呈现季节性增加外,其他年份 FluA 核酸检测阳性率均在冬春季出现一个高峰。不同部位或地点采集的标本中,宰杀或摆放禽肉案板表面阳性率最高（FluA39．49％,H58．41％,H77．41％,H923．84％）,而采集的粪便标本阳性率最低（FluA14．99％,H51．73％、H72．38％、和 H97．23％）;所采集的标本所对应的相关动物种类中,鸡（64．08％）、鸭（55．84％）和鸟类（51．92％）的禽流感病毒阳性率都达到50％以上,H5、H7和 H9在各禽类中均可以检出。同时发现,在环境中检出 H7亚型多的地区分布与其相应地区 H7N9感染的病例数呈显著相关性,（r ＝0．689,P ＜0．05）;对2322份样本进行 H6亚型核酸检测,总阳性率为2．58％,并选取 H5、H6和 H9亚型标本153份进行 N 亚型检测,检测出 H5N1、H5N2、H5N6、H6N2和 H9N2等多种亚型。2012-2015年广东省21个地市活禽市场均存在 HA 亚型（H5、H7、H9和 H6）和 NA 亚型（N1、N2、N6）等多种亚型的污染,污染程度呈现季节性分布,不同样本类型和禽类其禽流感病毒分状况不同,H7亚型的污染严重程度与 H7N9的病例感染数呈正相关性。     

2009～2013年我国活禽市场环境样本中禽流感病毒的检测

为了解中国活禽市场环境样本中禽流感病毒分布情况,对全国2009~2013年采自活禽市场的环境样本进行流感病毒核酸检测,并利用无特殊致病原鸡胚(SPF鸡胚)对A型流感病毒核酸阳性标本进行病毒分离。结果显示,环境标本中禽流感病毒核酸阳性率的波动呈明显的季节性趋势,冬春季节核酸检测阳性率较高;我国南方地区活禽市场环境样本的禽流感病毒核酸阳性率高于北方。市场中清洗禽类的污水和宰杀或摆放禽肉案板表面的擦拭样本核酸阳性率高于其它类型的样本。2009~2013年环境样本中分离到的禽流感病毒以H5和H9亚型为主,2013年之前H5亚型多于H9亚型,而2013年H9亚型超过了H5亚型。本研究表明,对城乡活禽市场中禽流感病毒的实时监测具有重要的公共卫生意义,可为我国人感染禽流感病毒的防控和预测预警提供依据。     

东洞庭湖地区野禽驯养繁殖基地的禽流感病毒调查

为了解东洞庭湖地区野禽驯养繁殖基地禽流感病毒感染状况,2011年11月至2013年10月,调查4家野禽驯养繁殖基地的养殖情况,同时采集环境标本(包括新鲜粪便标本和水标本)。利用PCR和病毒分离方法对标本进行检测。部分标本进行了核酸检测,禽流感病毒(AIV)阳性率为36.62%,2012年3月份阳性率最高(47.83%)。粪便标本、水标本的AIV阳性率分别为40.45%、30.19%,二者无统计学差异。共分离到28株AIV病毒,亚型包括H10、H4、H5和N7、N8,集中于11~12月的标本,主要来源于君山区野禽驯养繁殖基地的雁类和野鸭的新鲜粪便标本。野禽驯养基地的环境标本中存在AIV病毒,以A(H10N7)为主,建议对其进行定期监测。     

苏州活禽市场禽流感病毒(H7N9)季节变化及HA、NA、PB2基因系统进化分析

自2013年3月中国首次发现新型禽流感病毒H7N9以来,其于2013-2014年期间发生流行,2015年也有散发性感染。该病毒的流行不仅危及家禽养殖业,还对公共卫生安全造成严重威胁。为调查活禽市场中H7N9的进化史和季节性变化,本研究于2013年7-12月在H7N9主要流行地区之一江苏省苏州市活禽市场采集2 655份鸡、鸭咽拭子样本,对样本中流感病毒核酸进行检测。结果显示,冬季样本中H7N9阳性率显著高于夏季样本,同时发现样本中存在H5、H7和H9亚型毒株之间的混合感染。进一步对H7N9阳性样本的HA、NA和PB2基因序列进行分析,结果表明阳性样本中HA、NA和PB2基因序列与新型H7N9病毒的相应基因序列同源,其在家禽体内传代时也在继续进化。特别是一些样品中PB2基因序列与H5N1病毒PB2基因序列的同源性较高。结果提示,苏州存在一种新型H7N9病毒基因重排的可能性,建议在活禽市场对所有禽流感病毒亚型进行持续监控,从而有助于流感病毒的及时防控。     

中国首次检出的H12N2亚型禽流感病毒的基因组特征和系统进化分析

本实验室自2011年开始在鄱阳湖周边地区开展家禽养殖户和活禽市场环境中的禽流感病毒监测,在2011~2016年的监测过程中,通过病毒分离和深度测序,发现了一株H12N2亚型禽流感病毒,这是在中国首次检出该亚型病毒。该标本来自一份鸭粪便标本,采集自江西省余干县的一个家禽养殖场。病毒的8个片段分别与来自鸭或者野禽中的病毒最为接近。对病毒的全基因组系统进化分析表明,该病毒属于欧亚谱系。HA蛋白裂解位点序列为PQAQDR/GLF,属于低致病性禽流感病毒,受体结合位点分析表明病毒对α-2,3唾液酸受体亲和力较好。病毒NA的茎部没有氨基酸的缺失,但是PB1蛋白的L13P和L473V可以增强病毒聚合酶在哺乳动物中复制的能力和病毒对于哺乳动物的毒性。M1蛋白N30D突变和T215A突变提示会增加流感病毒对于哺乳动物的致病性。本次从家禽养殖场环境中检出野鸟相关的禽流感病毒进一步说明了在该地区进行禽流感病毒监测的重要性,以及在家禽-野鸟界面加强生物安全措施的必要性,需要持续进行监测,为禽流感病毒的暴发提供预警,为人感染禽流感病毒提供风险评估的依据。     

2019年不同类型流感病毒在佛山地区流行特征分析

2017-2018年间,流感病毒在我国流行态势严重,为探讨佛山地区流感病毒的流行特征,为佛山市流感的防控提供科学依据,本研究搜集2019年佛山市流感监测哨点医院采集的流感样病例标本,采用实时荧光RT-PCR检测流感病毒核酸,分析佛山市流感流行病学数据库病人详细信息,分析流行趋势及病毒流行的类型,为制定流感的防控提供科学依据.结果显示:2019年共检测流感样病例咽拭子标本1356例,流感病毒核酸检测阳性率为25.52％,甲型流感病毒阳性率为19.17％,乙型流感病毒阳性率为6.34％.不同职业人群共18个,小学生(7.67％),幼托儿童(3.17％)流感病毒核酸检测阳性率较高.把年龄分成5个年龄段进行分析,流感阳性率最高的是25～59岁组与5～14岁组.2019年佛山地区主要检出新甲H1型、季H3型、BV型三种型别,1月份,12月份为流感活跃的两个高峰,各型别在不同的时间交替或共同流行.不同性别的人群流感阳性率差异无统计学意义.不同型别病毒株在不同性别人群间阳性率差异无统计学意义.本研究结果提示佛山地区主要以甲型流感流行为主,优势亚型为新甲H1型,季H3型,部分乙型流感患者,以BV型为主.流感病毒感染的重点人群是小学生与幼托儿童,不同类型的流感病毒,在不同性别人群间感染无差异.通过对2019年佛山市流感流行特征的分析可以为佛山市流感的防控提供科学依据.     

H7亚型禽流感病毒概述

自2002年以来,全球报道的人感染H7亚型禽流感病毒病例超过100人,波及荷兰、意大利、加拿大、美国以及英国等国家。人感染H7亚型禽流感病毒的临床表现由结膜炎至轻微的上呼吸道疾病,甚至是肺炎。2013年3月31日,中国报道了上海市和安徽省两地共3例H7N9亚型禽流感病毒(AIVs)感染死亡病例。由于从家禽中分离到的H7亚型流感病毒不断增加,而且H7亚型AIVs感染人所导致的严重的临床症状,因此该亚型流感病毒对人类健康造成严重威胁,所以我们必须提高对H7亚型AIVs的认识,并要加强人群和动物中流感病毒的持续监测以及疫苗和药物的研究,以应对可能由于H7亚型AIVs引起的流感大流行。     

H7亚型禽流感病毒与禽类和人类的关系

2013年在中国首次发生了H7N9亚型流感病毒感染人事件,已经证实H7N9型禽流感是一种新型禽流感,是全球首次发现感染人类的新亚型流感病毒,以往这种病毒只在野生鸟类存在和传播。H7N9型禽流感病毒属于H7亚型中的一种,全球感染人的H7亚型病毒主要分为两大支系,即北美支系和欧亚支系,感染人的流感亚型也主要集中在H7N7,H7N3,H7N2等亚型上。为了清晰的了解H7亚型病毒的来龙去脉,本文重点讨论了A亚型流感病毒的宿主分布、H7亚型病毒感染禽类和人类的历史、H7亚型病毒的生物学特性以及未来研究展望。     

H5N8亚型高致病性禽流感病毒的全球流行概况

H5N8亚型高致病性禽流感病毒(highly pathogenic avian influenza virus,HPAIV)随候鸟的迁徙活动及商业贸易活动现已蔓延至亚洲、欧洲、非洲、美洲等国家和地区.2014-2015和2016-2019年H5N8亚型HPAIV已引发两波全球疫情,现正经历第三波疫情,导致家禽及野生鸟类...     

H5亚型禽流感病毒一步法RT-PCR检测方法的建立

针对家禽中流行较为广泛、危害相对大的H5亚型禽流感病毒的血凝素（HA）基因,通过分析流感数据库221个HA序列,在保守区内用Oligo6.0软件设计并合成了一对引物,建立了用于快速诊断H5亚型禽流感病毒的一步法RT-PCR方法,其扩增的目的片段大小为372bp。通过对H5亚型禽流感病毒尿囊液和棉拭子浸出液进行不同稀释倍数检测,结果表明病毒尿囊液最低检出量为10-4稀释;阳性棉拭子最低检出量为8倍稀释。用病毒分离和该方法同时检测不同脏器、口咽及泄殖腔棉拭子样品,结果表明该方法检测灵敏度比病毒分离低10～100倍。用该方法检测H1～H15亚型禽流感病毒和鸡新城疫病毒等其他14种禽病病原,仅有H5亚型禽流感病毒扩增出特异性目的条带。该方法具有方便快捷、特异性强、敏感性高等特点,为我国禽流感的快速诊断和分子流行病学调查提供了技术支撑。     

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.     

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。     

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。     

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。     

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.     

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.     

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.     

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.