乌鲁木齐市3~5岁儿童口腔微生物与肠道微生物的构成差异

目的探索乌鲁木齐市3～5岁儿童口腔微生物与肠道微生物的菌群构成及多样性等差异。方法从本团队前期流行病学调查的乌鲁木齐市3～5岁儿童中,按调查时间顺序随机抽取12名儿童。分别收集唾液及粪便样本共计24份,分为口腔微生物组和肠道微生物组。利用16S V3-V4区设计引物来进行PCR扩增,使用MiSeq测序仪进行二代测序,比较两组的微生物构成及多样性差异。结果门水平上:放线菌门(t=5.98,P0.001)、变形菌门(z=20.0,P=0.005)、TM7(z=78.0,P0.001)在口腔中丰度较高;厚壁菌门(z=134.0,P0.001)在肠道中丰度较高。厚壁菌门/拟杆菌门的值在肠道中较大(z=113.0,P=0.017)。属水平上:罗斯菌属、普雷沃菌属、链球菌属为口腔中丰度较高的菌属;粪杆菌属、Ruminococcaceae、拟杆菌属为肠道中丰度较高的菌属(P0.001)。奈瑟菌属、卟啉单胞菌属等仅存在于口腔中。Catenibacterium、肠杆菌属等仅存在于肠道中。菌群功能显示:在细胞运动(z=136.0,P0.001)、碳水化合物代谢(t=-4.71,P0.001)等方面表现出肠道组占优势;在遗传信息的翻译(t=8.17,P0.001)、神经退行性疾病(z=78.0,P0.001)等方面表现出口腔组占优势。结论放线菌门、变形菌门、TM7在口腔中丰度较高;厚壁菌门在肠道中丰度较高。口腔和肠道微生物在菌群功能上差异较大。奈瑟菌属、卟啉单胞菌属、Catenibacterium等可能为某些全身系统性疾病的标志性菌属。     

先兆流产患者阴道微生态与Th1及Th2细胞因子的关系探讨

目的探讨先兆流产患者阴道微生态与Th1及Th2类细胞因子的关系。方法回顾性分析2019年2月-2020年2月医院收治的98例先兆流产患者的资料,记为A组,另回顾性分析同期在该院体检的92例健康孕妇的资料,记为B组。对比A组和B组阴道微生物菌群组成,对比A组和B组血清Th1及Th2类细胞因子水平,采用Pearson相关性分析,分析先兆流产患者阴道微生物菌群相对丰度与血清Th1及Th2类细胞因子水平的相关性。结果A组阴道微生物群Chao1指数、Shannon指数均低于B组(P<0.05),A组阴道微生物群门水平上放线菌门、变形菌门、拟杆菌门和属水平加德纳菌、奇异菌属、普氏菌属相对丰度均高于B组(P<0.05),门水平厚壁菌门、梭杆菌门和属水平乳酸杆菌属的相对丰度均低于B组(P<0.05);A组Th1类细胞因子TNFα和IL2水平高于B组(P<0.05),Th2类细胞因子IL4和IL10水平低于B组(P<0.05);采用Pearson相关性检验,先兆流产患者阴道微生物群门水平厚壁菌门、梭杆菌门、属水平乳酸杆菌属的相对丰度分别与TNFα和IL2水平呈负相关(P<0.05),分别与IL4和IL10水平呈正相关(P<0.05),放线菌门、变形菌门、拟杆菌门、加德纳菌属、奇异菌属、普氏菌属的相对丰度分别与TNFα和IL2水平呈正相关(P<0.05),分别与IL4和IL10水平呈负相关(P<0.05)。结论先兆流产患者阴道微生物菌群分布与血清Th1及Th2细胞因子水平相关。     

基于高通量测序的油茶地区人群肠道菌群多样性

目的探索广西油茶地区人群肠道菌群的特征。方法采用1∶1病例对照研究方法,在广西油茶地区和非油茶地区按性别、年龄匹配收集20对健康男性人群粪便和血样,同时收集个体一般信息和食物摄入信息;测定血生化指标,采用16S rDNA的 V4-V5区序列进行高通量测序分析肠道菌群的差异。 结果油茶组人群肠道菌群丰度(Ace指数、Chao1指数)较非油茶组显著增加(t=2.202、3.210,P=0.034、0.003);厚壁菌门、柔壁菌门在油茶组中丰度显著高于非油茶组,拟杆菌门、梭杆菌门在非油茶组中显著高于油茶组;油茶组Dialister、Faecalibacterium、毛螺旋菌属、普雷沃菌属、棒状杆菌、微球菌、双歧杆菌的丰度显著高于非油茶组;油茶组人群体质量、BMI、血清总胆固醇、低密度脂蛋白、超敏C 反应蛋白水平显著降低(t或z=2.682、3.843、2.238、2.702、1.581,P=0.007、<0.001、0.031、0.010、0.013)。结论广西油茶地区人群肠道菌群多样性具有显著特征,为通过肠道菌群研究油茶的健康效应提供了新的理论依据。     

唾液菌群特征分析对儿童龋齿复发的预测价值

目的探究唾液菌群特征对儿童龋齿复发的预测价值。方法收集2017年1月至2018年1月在中铁十七局集团有限公司中心医院诊断及治疗的龋齿患儿94例,在进行龋齿治疗后第4周搜集唾液样本,并根据12个月后的龋齿发生情况分为复发组及未复发组,对比两组微生物检测结果,并使用ROC曲线评估微生物指标对龋齿复发的预测效能。结果本研究随访结束时,龋齿复发23例(25.84%)。龋齿复发与未复发组的唾液微生物组成存在显著差异:复发组的变形链球菌(Streptococcus mutans)、内氏放线菌(Actinomyces naeslundii)、普雷沃氏菌属(Prevotella)、二氧化碳噬纤维菌属(Capnocytophaga)、普雷沃氏菌科(Prevotellaceae)、放线菌属(Actinobacillus)的相对丰度显著高于未复发组(均P<0.05),未复发组在纤毛杆菌属(Leptotrichia)、奈瑟氏菌属(Neisseria)、链球菌属(Streptococcus)的相对丰度显著高于复发组(均P<0.05)。纤毛杆菌属、内氏放线菌、普雷沃氏菌属、变形链球菌载量预测龋齿复发的AUC值分别为0.753、0.715、0.680、0.940,其中变形链球菌的AUC值显著高于其他三种菌属(均P<0.05)。结论分析唾液菌群对儿童龋齿的复发具有一定的预测价值,其中变形链球菌的预测效能较好。     

胃癌患者化疗前后口腔菌群与肠道菌群变化特征

目的研究胃癌患者化疗前后口腔菌群与肠道菌群的变化特征,为该类患者的治疗提供参考。方法选取2017年2月至2020年2月于我院接受治疗的96例胃癌患者为观察组,另外选取同期我院健康体检者90例为对照组,收集两组对象唾液样本和粪便样本,其中观察组患者需收集化疗前及化疗后两个时间点的样本。采用16S rRNA基因高通量测序法检测菌群构成,分析两组对象组间及观察组患者化疗前后口腔菌群与肠道菌群变化特征。结果化疗前,观察组患者唾液样本、粪便样本菌群Simpson指数、Shannon指数、厚壁菌门、拟杆菌门丰富度与对照组比较差异均无统计学意义(均P>0.05)。化疗前,观察组患者唾液样本及粪便样本中放线菌门丰富度显著高于对照组,变形菌门丰富度显著低于对照组(均P<0.05)。化疗后,观察组患者唾液样本中厚壁菌门、放线菌门、变形菌门丰富度较化疗前显著下降,拟杆菌门丰富度显著上升(均P<0.05);同时粪便样本中厚壁菌门、变形菌门丰富度较化疗前显著上升,拟杆菌门、放线菌门丰富度显著下降(均P<0.05)。化疗后,观察组患者唾液样本中韦荣球菌属、罗氏菌属、普氏菌属丰富度较化疗前显著增加,放线菌属、链球菌属、奈瑟菌属、粪梭杆菌属丰度显著下降(均P<0.05);同时粪便样本中链球菌属、肠志贺菌属、乳杆菌属丰富度较化疗前显著增加,粪梭杆菌属、双歧杆菌属、拟杆菌属丰富度显著下降(均P<0.05)。结论化疗对胃癌患者口腔菌群及肠道菌群构成有一定程度影响,患者口腔菌群中韦荣球菌属丰度上升,而肠道中正常菌群的生长受抑制。     

小儿支原体肺炎合并气道黏液栓形成的气道微生物菌群变化

目的 研究支原体肺炎（MPP）合并气道黏液栓的患儿气道微生物菌群的变化。方法 选取2018年1月至2020年1月在我院诊治的116例MPP患儿为研究对象。根据支气管镜检查结果,将56例合并气道黏液栓的MMP患儿纳入MPP合并黏液栓组,60例无气道黏液栓的MPP患儿纳入单纯MPP组。用16S r RNA测序技术分析各组患儿支气管灌洗液中气道菌群的组成,比较各组气道微生物菌群分布差异,采用Pearson相关性分析探讨MPP合并黏液栓组菌属与临床参数的相关性。结果 单纯MPP组和MPP合并黏液栓组的优势菌门是软壁菌门、拟杆菌门、厚壁菌门。MPP合并黏液栓组软壁菌门和变形菌门相对丰度显著高于单纯MPP组（P=0.012、0.001）,两组的拟杆菌门、厚壁菌门、放线菌门和梭杆菌门相对丰度间差异无统计学意义（P>0.05）。单纯MPP组和MPP合并黏液栓组的优势菌属包括支原体属、放线菌属、鞘氨醇单胞菌属、苯杆菌属、伊丽莎白菌属、普氏菌属、链球菌属和韦荣球菌属。相比于单纯MPP组,MPP组合并黏液栓组支原体属、放线菌属的相对丰度较高（P<0.001）,鞘氨醇单胞菌属和伊丽莎白菌属相对丰度...     

细菌性阴道病肠道菌群与阴道菌群16S rDNA测序分析

目的通过对细菌性阴道病(BV)患者肠道菌群及阴道菌群16S rDNA扩增子测序,分析其结构、多样性、相关性以及BV对肠道菌群的影响,为今后治疗BV提供新的思路。方法选取符合纳入标准的BV患者11例(BV组),健康者9例(C组),留存阴道分泌物及新鲜粪便进行16S rDNA基因检测分析。结果C组阴道菌群以乳杆菌属为主,BV与加德纳菌属、普雷沃菌属、Sneathia、窄食单胞菌属(Stenotrophomonas)、阿托波菌属、Shuttleworthia、巨型球菌属密切相关。BV组肠道、阴道菌群丰富度均高于C组。Alpha多样性分析中C组和BV组肠道菌群、阴道菌群的Shannon指数组间比较,χ²值为29.137, P=0.000<0.05,两组阴道菌群Shannon指数组间比较差异具有统计学意义(P<0.05),BV组高于C组。物种多样性曲线反映本研究样本测序数据量的合理性,表明BV组的肠道菌群多样性、丰富度均高于C组,主坐标分析表明C组肠道与阴道的菌群结构差距较大,BV组肠道与阴道的菌群结构有相似之处,且两组肠道菌群结构接近。BV组阴道菌群中厚壁菌门丰度较C组低,放线菌门、拟杆菌门较C组高;BV组肠道菌群中拟杆菌门丰度较C组低;C组肠道中拟杆菌门明显高于阴道,厚壁菌门明显低于阴道; BV组阴道菌群中放线菌门丰度高于C组,差异均具有统计学意义(P<0.05)。结论BV阴道菌群与肠道菌群具有相关性,BV可能引起肠道菌群结构比例和多样性的改变。     

甲流患儿鼻咽部及口咽部的菌群分析

目的比较甲流(IA)患儿鼻咽部及口咽部菌群与健康儿童的差异,分析甲型流感病毒(IAV)感染后可能对儿童鼻咽部及口咽部菌群的影响。方法选取我院120例甲流患儿作为病例组,120例年龄性别相近的健康儿童作为健康组,采用高通量测序技术,对采集的所有鼻咽部及口咽部标本行16S rDNA基因测序分析,比较两组儿童间的菌群多样性及在门、属水平上菌群结构的差异。结果病例组鼻咽部及口咽部的菌群多样性均高于对照组(Ps0.05)。在门水平上,两组儿童鼻咽部及口咽部的第一优势菌门均为厚壁菌门(Firmicutes)(Ps0.05),病例组鼻咽部的变形菌门(Proteobacteria)相对丰度显著高于健康组(Ps0.05);在鼻咽部菌属水平上,病例组中正常优势菌莫拉氏菌属(Moraxella)、棒状菌属(Corynebacterium)、狡诈菌属(Dolosigranulum)、普氏菌属(Prevotella)等的相对丰度显著减少(Ps0.05),而链球菌属(Streptococcus)、嗜血杆菌属(Haemophilus)、盐单胞菌属(Halomonas)、不动杆菌属(Acinetobacter)、罗尔斯通菌属(Ralstonia)等的相对丰度显著增加(Ps0.05),叶杆菌属(Phyllobacterium)仅见于病例组;在口咽部菌属水平上,病例组菌群相对减少的有奈瑟菌属(Neisseria)、乳杆菌属(Lactobacillus)等,而葡萄球菌属(Staphylococcus)、奇异菌属(Atopobium)、放线菌属(Actinomyces)等的相对丰度显著增加(Ps0.05)。结论通过对甲流患儿进行上呼吸道菌群分析,揭示了甲流患儿鼻咽部及口咽部菌群的失调,这提示我们可从微生态角度研究甲流,从而进一步了解甲流的发病机制,为减少甲流严重并发症及病死率提供可能的理论依据。     

胃微生物菌群与幽门螺杆菌感染的胃贲门腺癌发病相关性分析

目的研究胃微生物菌群与胃贲门腺癌发病的相关性。方法选择2016年4月-2018年4月在本院就诊的胃贲门腺癌(GCA)患者109例。患者均经病理科组织病理确诊为GCA。对照组为健康人群100例,根据有无H.pylori检出将对照组和GCA组患者分为有H.pylori和无H.pylori感染,其中对照组H.pylori检出19例,未检出81例,GCA组H.pylori检出53例,未检出56例。用胃镜采集贲门胃黏膜,置于无菌冻存管放入液氮中保存,使用16SrRNA的方法进行胃黏膜微生物检测。结果 GCA组患者幽门螺杆菌(H.pylori)感染例数明显高于对照组,无论有无H.pylori感染的对照组人群中,丰度较高的菌属是不动杆菌(Acinetobacter),罗斯氏菌(Rothia),嗜血杆菌(Haemophi-lus),拟杆菌(Bacteroides),链球菌(Streptococcus),韦荣球菌(Veillonella),普氏菌(Prevotella)。无H.pylori组内,GCA组样本中普氏菌(Prevotella)、瓦氏菌(Shewanella)、盐单胞菌(Halomonas)丰度明显高于对照组,有H.pylori组内,GCA组样本中普氏菌(Prevotella)、瓦氏菌(Shewanella)、盐单胞菌(Halomonas)、卟啉单胞菌(Porphyromonas)、梭杆菌(Fusobacterium)丰度明显高于对照组,不动杆菌(Acinetobacter)明显低于对照组。有H.pylori的GCA组样本中普氏菌(Prevotella)、瓦氏菌(Shewanella)、盐单胞菌(Halomonas)、卟啉单胞菌(Porphyromonas)、梭杆菌(Fusobacterium)丰度明显高于无H.pylori的GCA组,不动杆菌(Acinetobacter)明显低于无H.py-lori的GCA组。结果还发现GCA与普氏菌(Prevotella)、瓦氏菌(Shewanella)、盐单胞菌(Halomonas)、卟啉单胞菌(Porphyromonas)、梭杆菌(Fusobacterium)正相关,与不动杆菌(Acineto-bacter)负相关。结论 GCA患者胃内菌群数量和分布与健康人群存在明显差异,H.pylori可能影响胃内菌群结构在GCA发病中发挥作用。     

抑郁症患者肠道菌群研究

目的研究抑郁症患者肠道微生物群落分布情况。方法选择2017年1月-2018年1月在本院临床心理科就诊的确诊为抑郁症的患者79例,以及同时期在本院体检的健康者80例。收集患者新鲜粪便,利用16SrRNA基因测序技术分析患者肠道菌群。结果对159例粪便标本进行16SrRNA基因测序,共获得1 276 841条有效16SrRNA基因序列,抑郁组Shannon指数明显高于对照组。在门水平,共发现20个细菌门,抑郁患者肠道菌群丰度前3位的分别是厚壁菌门、拟杆菌门、梭杆菌门;在科水平,前3位主要为拟杆菌科、普雷沃氏菌科和瘤胃菌科;在属水平,前3位分别是多形杆菌属、普氏菌属、另枝菌属。对照组肠道菌群丰度前3位的分别是厚壁菌门、拟杆菌门、梭杆菌门;在科水平,前3位主要是拟杆菌科,普雷沃氏菌科和瘤胃菌科;在属水平,前3位分别是多形拟杆菌属、普氏菌属、另枝菌属。抑郁组多形杆菌属、普氏菌属、另枝菌属、栖粪杆菌属、考拉杆菌属丰度明显低于对照组,抑郁组毛螺菌属、副杆菌属、布劳特氏菌属、巨单胞菌属丰度明显高于对照组。抑郁组拟杆菌属和栖粪杆菌属丰度与SDS评分成负相关,毛螺菌属丰度与SDS评分成正相关。结论抑郁症患者病情严重程度与抗炎性细菌拟杆菌属和栖粪杆菌属丰度成反比,与毛螺菌属丰度成正比。     

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.