动物园大型猫科动物犬瘟热的免疫监测

虎、狮、豹等大型猫科动物可发生犬瘟热(CD),有必要进行预防.采取某动物园未免疫的东北虎、非洲狮、猞猁血样,用中和试验检测,结果显示这些动物的犬瘟热病毒(CDV)抗体水平均小于15.用CD弱毒疫苗接种以上动物,幼龄动物免疫14d逐步产生抗体;成年动物体内抗体水平在两月内迅速升高,并维持在164以上,9～11个月后逐步下降,加强免疫后抗体又迅速升高至≥1112.该疫苗对所有接种的动物均安全可靠.白化的孟加拉虎接种疫苗后不能产生CDV中和抗体.     

犬瘟热弱毒疫苗对大熊猫的免疫效果评价

以国产犬用犬瘟热等六联弱毒苗接种33只不同性别、不同年龄的健康大熊猫,分别采集每只大熊猫免疫前以及免疫后2周、1个月、3个月、6个月、9个月、11个月的血清样品,采用细胞中和试验测定犬瘟热病毒(CDV)中和抗体效价,并对接种疫苗后的所有大熊猫个体进行连续1年的健康资料记录.结果表明,所有接种疫苗的大熊猫均未出现任何与疫苗相关的副反应,该疫苗接种对大熊猫是安全的;部分老年、成年和亚成年的大熊猫(13/33)在疫苗接种前已经存在CDV抗体(≥1:4);2只老年大熊猫在疫苗接种后仅产生低水平的CDV抗体(≤1:8),另外2只老年大熊猫在疫苗接种后未产生CDV抗体(＜1:4);部分成年大熊猫(9/15)在疫苗接种后未产生CDV抗体(＜1:4),仅部分成年大熊猫(6/15)在疫苗接种后产生低水平的CDV抗体(≤1:22);部分亚成年大熊猫(8/9)在疫苗接种后能够产生低水平的CDV抗体(≤1:22),少数亚成年大熊猫(1/9)在疫苗接种后未产生CDV抗体 (＜1:4);幼年大熊猫(5/5)疫苗接种后可产生CDV抗体,2周至1月内达到高峰,CDV抗体水平和持续时间都明显高于老年、成年和亚成年大熊猫(P＜0.05);少数幼年大熊猫(1/5)疫苗接种后CDV抗体达到1:127,但3个月后所有幼年大熊猫CDV抗体就陡然下降(≤1:16).由此表明,在现有的免疫剂量和程序下,犬用犬瘟热等六联弱毒疫苗难以有效刺激大熊猫产生CDV中和抗体.     

犬瘟热病毒H蛋白基因重组腺病毒的构建及免疫效果评估

研究选取犬瘟热病毒H蛋白基因为目的基因,利用反转录聚合酶链式反应(RT-PCR)、酶切、连接等方法构建出重组人5型腺病毒穿梭质粒和骨架质粒,两者共转染293AD细胞并包装出重组腺病毒。通过电镜负染、酶切鉴定、Western blot及一步生长曲线测定等方法进行病毒的生物学特性鉴定,证明犬瘟热病毒H蛋白基因重组腺病毒构建正确。犬分别肌肉接种CDV疫苗毒和重组腺病毒,并检测免疫后第14,28,42,56,70,84d时犬血清中抗CDV中和抗体的变化情况。结果显示,犬免疫重组腺病毒后体内产生的抗CDV平均中和抗体水平高于对照组,滴度最高达2-8。研究表明,正确构建的重组腺病毒具有良好的免疫原性,诱导产生的抗犬瘟热病毒中和抗体达到犬最低免疫保护水平,为进一步研发犬瘟热病毒活载体疫苗提供理论依据。     

稳定表达貉犬瘟热病毒细胞受体SLAM的Vero细胞系的建立及应用

[目的]信号淋巴激活分子(SLAM又称CD150)为犬瘟热病毒(Canine distemper virus,CDV)的细胞受体.本研究目的在于建立稳定表达犬瘟热易感动物貉SLAM基因的Vero细胞系,用于犬瘟热诊断及CDV强毒株的快速分离.[方法]从重组质粒pMD-18-T-rSLAM扩增rSLAM基因编码区,通过分子克隆技术构建真核表达质粒pIRES2-EGFP-rSLAMhis.将该质粒转染Vero细胞后,经EGFP荧光观察、G418抗性压力和单细胞克隆化及RT-PCR筛选表达rSLAM阳性细胞系.应用获得细胞系对临床犬瘟热病例进行病毒分离,对分离得到CDV进行RT-PCR鉴定及动物回归试验.[结果]经过RT-PCR和免疫组化试验证实,本实验筛选获得一株能稳定表达rSLAM的Vero细胞系——Vero-rSLAM.该细胞系接种CDV阳性样品36-48h即可产生典型CDV致细胞融合病变,而其亲本Vero细胞接种至6d均无可见细胞病变出现.应用Vero-rSLAM细胞系从狐狸、貉犬瘟热阳性病料中分离获得了3株犬瘟热病毒.其中犬瘟热病毒LN(10) f1株对易感狐狸、貉均可产生致死性感染.[结论]成功建立了稳定表达rSLAM的Vero细胞系,用它分离的CDV对本动物保持较强的毒力.     

犬瘟热病毒基因变异及其细胞受体研究进展

由犬瘟热病毒(Canine distemper virus,CDV)引起的犬瘟热(CD)一直是对世界养犬业、毛皮动物养殖业以及野生动物保护事业危害最为严重的传染病之一,甚至在广泛应用疫苗防制CD的近年,世界各地仍有犬或野生动物感染CDV并造成CD流行的报道.通过对CDV主要抗原基因--血凝基因(H基因)氨基酸序列分析,CDV可分为6个基因型.研究证实,CDV野毒株在抗原性上与疫苗株存在较大差异,因此推测H蛋白抗原变异造成了弱毒疫苗免疫效力的降低进而导致了某些地区CD的爆发.CDV作为一种宿主范围广泛的病毒,其细胞受体--信号淋巴细胞激活因子(SLAM)和硫酸乙酰肝素(HS)在哺乳动物体内的广泛存在是CDV跨物种间感染的重要因素.本文就国内外最新研究进展并结合作者的工作,对上述问题进行了综述和探讨.     

儿童2剂水痘疫苗不同间隔免疫程序的比较

目的了解水痘疫苗2剂不同间隔时间免疫程序的安全性及免疫原性。方法按照随机、双盲的原则,选择符合条件的1~3岁、4~6岁、7~12岁儿童各200名,每个年龄组按照2剂间隔3个月和6个月的免疫程序,分别接种2剂冻干水痘减毒活疫苗。观察各组接种后的不良反应率,用膜抗原荧光抗体法(FAMA)检测疫苗接种前、后血清抗体阳转率、GMT水平和平均增长倍数。结果接种2剂水痘疫苗后,总体不良反应率在4%~13%;同年龄组不同间隔时间接种2剂疫苗后,不良反应发生率差异无统计学意义;不同年龄组间不良反应发生率差异无统计学意义。同年龄组不同间隔时间免前及接种2剂后,血清GMT水平差异均无统计学意义;同年龄组接种1剂与2剂水痘疫苗的血清GMT水平,两者间差异有显著性统计学意义。接种2剂水痘疫苗的GMT增长倍数高于接种1剂。不同间隔时间接种第2剂水痘疫苗后抗体阳转率差异无统计学意义;同年龄组接种2剂后抗体阳转率高于接种1剂,两者差异有统计学意义。结论间隔3个月和6个月接种第2剂水痘疫苗,在安全性及免后GMT水平、增长倍数及抗体阳转率等4个方面,两者差异均无统计学意义。     

Beagle犬免疫血清犬瘟热抗体检测

采用琼脂扩散法测定血清抗体效价,同时采用微量细胞中和实验测定中和效价,检测60份Beagle犬免疫血清犬瘟热(CD)抗体.结果表明25日龄仔犬血清母源抗体维持在较高的水平,以后逐渐下降,至35日龄(首免日)血清母源抗体水平下降1～2个滴度,首免后1个月、3个月、6个月免疫抗体水平逐渐上升.根据抗体水平应选择35日龄首免.本试验为 Beagle犬瘟热病预防选择疫苗和制定合适的免疫程序提供参考,实验设定的两种免疫程序在临床上都可以使用.     

重组(汉逊酵母)乙型肝炎疫苗副反应和抗体应答观察

观察重组(汉逊酵母)乙肝疫苗免疫儿童的副反应和抗体应答。按0、1、6月免疫程序,分别应用2批重组汉逊酵母疫苗和2批重组酿酒酵母疫苗,免疫221名6至12岁儿童,其中汉逊酵母疫苗1批(A)接种102人,另一批(B)接种26人,重组酿酒酵母疫苗1批(C)和另1批(D)分别接种74和19人。观察每次接种后的副反应和全程免疫一月后(T7)的抗体应答。儿童接种汉逊酵母疫苗后副反应发生率低,有个别出现发热反应,但均低于37.8℃,且为一过性。T7时4组儿童抗HBs血清阳转率均在96%以上,GMT范围在229.98～338.83IU/L之间。免疫A批疫苗儿童组抗体滴度(GMT)显著高于免疫C批疫苗组(270.33、229.98IU/L;P<0.05)。汉逊酵母乙肝疫苗具有较好的安全性,免疫儿童抗体应答水平较高。     

重组腺病毒载体乙肝疫苗的免疫学研究

目的比较腺病毒(Adenovirus,Ad)载体乙型肝炎病毒(Hapotitis B virus,HBV)疫苗鼻腔黏膜、皮下注射接种小鼠免疫效果.方法以腺病毒为载体、以HBV preS2/S为目的基因构建重组疫苗,然后将重组疫苗分别鼻黏膜和皮下接种BALB/c小鼠,与阴性对照组(载体对照组、生理盐水对照组)比较接种重组疫苗35、72 d的免疫效果.结果鼻腔接种Ad HBV疫苗组动物在72 d时血清抗体终末效价为1/2 470,同时可提高NK细胞杀伤能力和干扰素-γ、IL-2含量升高.皮下注射Ad HBV在免疫35 d和72 d、1∶200血清稀释度均未测到阳性抗体(A值,P/N值＜2.1).结论重组疫苗黏膜接种诱导小鼠产生特异抗体和细胞免疫反应高于皮下接种途径.     

甲型H1N1流感病毒佐剂疫苗小鼠免疫效果

为了探讨甲型H1N1流感病毒氢氧化铝佐剂疫苗对小鼠的免疫作用及对小鼠繁殖性能的影响,以不同剂量、不同免疫程序免疫小鼠后定期采血;用血凝抑制(HI)方法检测血清H1N1流感病毒HI抗体滴度,观察H1N1流感病毒佐剂疫苗对小鼠受孕、产仔、哺乳的影响;比较孕鼠及非孕鼠的抗体滴度,免疫后孕鼠所产仔鼠的体重及H1N1胎传抗体水平。结果显示,以0.5μg组开始的不同剂量、不同免疫程序均可使小鼠产生90倍以上水平的H1N1流感病毒抗体;免疫后的小鼠不影响受孕、产仔及哺乳;仔鼠保护性抗体可持续1个月以上。H1N1流感病毒佐剂疫苗是一种高免疫原性的制剂,用低剂量免疫,即可产生90倍以上持续时间较长的保护性抗体。这种佐剂疫苗对小鼠的繁殖性能无明显影响,免疫产生的抗体经胎盘可垂直传递给仔鼠。     

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.     

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。     

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。     

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.     

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.     

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.