18F-FDG PET 和治疗量131I 全身扫描对分化型甲 状腺癌根治术后转移灶检测的临床价值评估

目的:探讨18F-FDG PET显像和131I-全身扫描(131I-WBS)SPECT显像对分化型甲状腺癌(DTC)术后转移灶的临床诊断价值。方法:对57例外科术后拟行131I治疗的DTC患者行18F-FDG PET全身显像和131I-WBS扫描,观察和记录在糖代谢和碘代谢中DTC转移灶的定位及数量变化,并同时测定甲状腺球蛋白(Tg),促甲状腺激素释放激素(TSH)等实验室检查项目。结果:57例DTC患者18F-FDG PET显像发现真阳性20例、假阳性3例、真阴性31例、假阴性3例,其灵敏度为87.0%,特异性为91.2%。而131I-WBS扫描发现真阳性13例、假阳性2例、真阴性34例、假阴性8例,其灵敏度为61.9%,特异性为94.4%。PET显像和131I-WBS扫描共检出阳性病灶73个,其中淋巴结32个,肺5个,纵隔6个,骨26个,其他部位4个。PET显像发现43个阳性病灶(58.9%),而131I-WBS检出30个(41.1%)。当Tg水平>10μg/L时,随着Tg在血清含量的增高,两种显像方法的对DTC转移灶的阳性检出率亦随之升高。结论:两种检查对DTC术后转移灶的监测和131I的治疗具有良好的互补性,18F-FDG PET显像在Tg阳性和131I-WBS阴性的患者的转移灶检出上更具有优势,有重要的临床指导意义。     

术前血清TSH水平联合多普勒超声对分化型甲状腺癌的诊断价值

目的:研究术前血清促甲状腺激素(TSH)水平联合多普勒超声对分化型甲状腺癌(DTC)的诊断价值。方法:选择从2015年1月到2017年6月在北京市第一中西医结合医院诊治的甲状腺结节患者528例作为研究对象。经病理学诊断显示DTC患者268例,记为观察组;良性甲状腺结节患者260例,记为对照组,检测并对比两组超声指标,两组TSH水平分布情况,分析观察组患者血清TSH水平与其颈淋巴结转移及肿瘤直径的关系,以及术前血清TSH联合多普勒超声对DTC的诊断价值。结果:观察组病灶数目为单个、病灶大小为小结节以及有沙粒样钙化者占比均分别明显高于对照组,差异均有统计学意义(均P0.05)。观察组TSH水平为2.20~4.20μIU/m L及4.20μIU/m L者占比均分别明显高于对照组,且0.27μIU/m L、0.27~1.44μIU/m L及1.45~2.19μIU/m L者占比均分别明显低于对照组,差异均有统计学意义(均P0.05)。观察组患者中,有颈淋巴结转移者的TSH水平明显高于无转移者,肿瘤直径为2~4 cm和4 cm者的TSH水平均分别明显高于2 cm者,且肿瘤直径4 cm者也明显高于2~4 cm者,差异均有统计学意义(均P0.05)。术前血清TSH联合多普勒超声对DTC的诊断结果中,灵敏度为73.88%(198/268),特异度为82.31%(214/260),准确度为78.03%(412/528),均分别高于单纯超声诊断的57.46%(154/268),75.77%(197/260),66.48%(351/528),差异有统计学意义(P0.05)。联合诊断的ROC曲线下面积是0.847,其中TSH诊断临界值是3.153 m IU/L。结论:应用术前血清TSH水平与多普勒超声的联合诊断方式能够有效诊断DTC患者,临床上可考虑将此种联合诊断方式进行推广,从而为DTC患者的诊治及病情评价发挥指导作用,值得给予重视。     

18F-FDG PET和治疗量131I全身扫描对分化型甲状腺癌根治术后转移灶检测的临床价值评估

目的：探讨18F-FDG PET显像和131I-全身扫描（131I-WBS）SPECT显像对分化型甲状腺癌（DTC）术后转移灶的临床诊断价值。方法：对57例外科术后拟行131I治疗的DTC患者行18F-FDG PET全身显像和131I-WBS扫描,观察和记录在糖代谢和碘代谢中DTC转移灶的定位及数量变化,并同时测定甲状腺球蛋白（Tg）,促甲状腺激素释放激素（TSH）等实验室检查项目。结果：57例DTC患者18F-FDG PET显像发现真阳性20例、假阳性3例、真阴性31例、假阴性3例,其灵敏度为87.0%,特异性为91.2%。而131I-WBS扫描发现真阳性13例、假阳性2例、真阴性34例、假阴性8例,其灵敏度为61.9%,特异性为94.4%。PET显像和131I-WBS扫描共检出阳性病灶73个,其中淋巴结32个,肺5个,纵隔6个,骨26个,其他部位4个。PET显像发现43个阳性病灶（58.9%）,而131I-WBS检出30个（41.1%）。当Tg水平〉10μg/L时,随着Tg在血清含量的增高,两种显像方法的对DTC转移灶的阳性检出率亦随之升高。结论：两种检查对DTC术后转移灶的监测和131I的治疗具有良好的互补性,18F-FDG PET显像在Tg阳性和131I-WBS阴性的患者的转移灶检出上更具有优势,有重要的临床指导意义。     

桥本氏病合并甲状腺乳头状癌患者血清甲状腺相关激素水平的变化及意义

目的:探究桥本氏病(HT)合并甲状腺乳头状癌(PTC)患者血清甲状腺相关激素水平的变化及意义。方法:对我院148例HT患者的临床资料进行回顾性分析,根据其是否合并PTC分为HT合并PTC组(n=68)和单纯HT组(n=80)。比较两组患者性别、年龄及血清促甲状腺激素(TSH)、甲状腺功能指标[游离三碘甲腺原氨酸(FT3)、游离甲状腺素(FT4)]、抗甲状腺抗体[甲状腺球蛋白抗体(TGAb)、甲状腺过氧物酶抗体(TPOAb)]水平等临床资料差异,分析血清TSH水平变化及意义。结果:HT合并PTC组患者男性比例、年龄、病程及血清TSH水平均大于单纯HT组,血清TGAb、TPOAb水平则均小于单纯HT组(P0.05);血清FT3、FT4水平比较差异无统计学意义(P0.05)。HT合并PTC患者组血清TSH4.2 m IU/L患者占比高于血清TSH正常组(P0.05)。血清TSH4.2 m IU/L患者中HT合并PTC患者的占比大于血清TSH水平正常的患者(P0.05)。HT合并PTC患者中,血清TSH水平4.2 m IU/L患者中央区淋巴结转移发生率高于血清TSH水平正常患者(P0.05);血清TSH4.2 m IU/L与血清TSH正常患者多灶癌发生率比较差异无统计学意义(P0.05)。结论:HT患者血清TSH水平升高可能促进其甲状腺组织癌变,HT合并PTC患者血清TSH水平升高可能促进其中央区淋巴结转移。     

术前血清促甲状腺激素水平与甲状腺结节相关性的研究

目的:探讨术前血清促甲状腺激素(TSH)水平与甲状腺结节良恶性的关系。方法:回顾性分析了1499例甲状腺结节手术切除患者术前血清TSH、甲状腺B超,手术记录、术后病理诊断报告。根据术后病理报告判定甲状腺结节良恶性,分析术前血清TSH水平在甲状腺良恶性结节中的不同分布。结果:分化型甲状腺癌(DTC)患者术前血清TSH水平明显高于甲状腺良性结节组(2.179±2.017vs1.259±0.884μIU/mL),P<0.001;在DTC患者中,有淋巴结转移较无淋巴结转移、TNM分期III、IV期较I、II期以及肿瘤直径≥1cm较<1cm的患者术前血清TSH明显升高(均P<0.001)。结论:术前血清TSH水平是预测甲状腺结节良恶性的重要指标。     

18F 一FD G PE T 显像在分化型甲状腺癌患者随访中的应用

分化型甲状腺癌（Differentiated thyroid carcinoma,DTC）在其病程演变过程中,分化程度较低的复发或转移灶摄^131I能力降低而对^18F-脱氧葡萄糖（Fluoredeoxyglucose,FDG）摄取增多。因此,依赖于^131I和FDG显像的两种不同机制,正电子发射型断层成像（Positron Emission Tomography,PET）探测非功能性DTC复发或转移灶兼具定位诊断、敏感性及特异性都高的优点。因此。DTE患者随访期间,对甲状腺球蛋白阳性（Thyroglobulin positive,TG＋）（在促甲状腺激素刺激作用下TG〉10μg／L或在促甲状腺激素被抑制作用下TG〉2μg／L）或TG阴性（TG negative,TG-）但TsAb〉200U／mL,且131I-诊断剂量全身显像阴性（Diagnostic whole—body scanning negative,dWBS-）的高危患者（Ⅲ期或Ⅳ期患者）是进行^18F—FDG PET显像的指征。同机融合显像设备PET／CT、PET／MRI具有更高的敏感性和分辨率,为病灶的定性和定位,提供更准确的信息。     

干预治疗对TPOAb阴性亚甲减孕妇妊娠结局的影响

目的:探讨干预治疗对不同TSH水平的妊娠期亚临床甲减合并甲状腺过氧化物酶(TPOAb)阴性孕妇妊娠结局的影响。方法:回顾性分析2016年1月1日至2016年12月31日在青岛大学附属医院产科分娩孕妇诊断为亚临床甲减且TPOAb阴性的孕妇不良妊娠结局的发生率,根据2011年(S1标准)及2017年(S2标准)美国甲状腺协会(ATA)指南对妊娠合并亚临床甲减推荐诊断的TSH水平不同分组,A组(4 m IU/LTSH10.0 m IU/L)131例,B组(TSH4 m IU/L,在T1期TSH2.5 m IU/L,T2、T3期TSH3.0 m IU/L)326例,根据是否接受左甲状腺素钠片(商品名:优甲乐)治疗,分为治疗组(295例)、未治疗组(194例),同时选取TPOAb阴性且甲状腺功能正常的孕妇(306例)作为对照组。结果:(1)依据S1、S2诊断标准,妊娠合并亚临床甲减的发生率分别为13.57%、3.6%,治疗率分别为39.67%、51.34%,不同诊断标准间比较差异具有统计学意义(P0.05)。(2)A组孕妇中,未治疗组妊娠期高血压疾病、妊娠期糖尿病、妊娠期贫血、流产、早产、胎儿窘迫的发生率均高于治疗组及对照组,差异具有统计学意义(P0.05),而治疗组与对照组比较差异无统计学意义(P0.05)。未治疗组胎盘早剥、胎膜早破、胎儿畸形、低体重儿的发生率虽高于治疗组及对照组,但两两比较差异均无统计学意义(P0.05)。(3)B组孕妇未治疗组妊娠期高血压疾病、妊娠期糖尿病、妊娠期贫血、流产、早产、胎儿窘迫、胎盘早剥、胎膜早破、胎儿畸形、低体重儿的发生率虽高于治疗组及对照组,三组及两两比较差异无统计学意义(P0.05)。结论:对于青岛地区TPOAb阴性的妊娠期亚临床甲减孕妇,4.0 m IU/LTSH10.0 m IU/L时,左甲状腺素钠片治疗能明显改善其不良妊娠结局。     

自身免疫性甲状腺功能紊乱孕妇血清TPOAb 检测的临床价值

目的:探讨血清甲状腺过氧化物酶抗体(TPOAb)对于患有自身免疫性甲状腺功能紊乱的孕妇的临床诊断价值。方法:筛选2009年9月至2013年1月我院收治的205例孕妇,其中甲状腺功能紊乱孕妇55例(紊乱组),非甲状腺功能紊乱孕妇150例(非紊乱组);非紊乱组中,年龄30岁的高龄孕妇50例(高龄组),年龄≤30岁的孕妇100例(正常组)。采用化学发光法,测定所有孕妇血清中游离甲状腺三碘原氨酸(FT3)、游离甲状腺素(FT4)、促甲状腺激素(TSH)和TPOAb水平。结果:紊乱组患者血清中TSH、TPOAb及TPOAb阳性率水平显著高于非紊乱组,且存在统计学意义(均P0.05),而两组患者血清中FT3和FT4水平无统计学意义(均P0.05);高龄组和正常组血清中TSH、FT3、FT4及TPOAb水平均无统计学意义(均P0.05);与TSH正常组相比,TSH异常组中约有超过半数TPOAb表现为阳性,有统计学意义(P0.05);孕妇体内的TSH水平正常与否,均有出现TPOAb阳性的可能,在TSH水平较高(4.67 m IU/L)中,TPOAb阳性概率更高。结论:TSH、FT3、FT4水平正常而TPOAb呈阳性的孕妇依然存在自身免疫性甲状腺功能紊乱的可能性,监测TPOAb的水平对于妊娠期孕妇功能紊乱的诊断与治疗具有重要意义。     

术前血清促甲状腺激素水平与甲状腺结节相关性的研究

目的：探讨术前血清促甲状腺激素（TSH）水平与甲状腺结节良恶性的关系。方法：回顾性分析了1499例甲状腺结节手术切除患者术前血清TSH、甲状腺B超,手术记录、术后病理诊断报告。根据术后病理报告判定甲状腺结节良恶性,分析术前血清TSH水平在甲状腺良恶性结节中的不同分布。结果：分化型甲状腺癌（DTC）患者术前血清TSH水平明显高于甲状腺良性结节组（2．179±2．017vsl．259±0．884μIU／mL）,P〈0．001;在DTC患者中,有淋巴结转移较无淋巴结转移、TNM分期Ⅲ、Ⅳ期较Ⅰ、Ⅱ期以及肿瘤直径≥1cm较〈1cm的患者术前血清TSH明显升高（均P〈0．001）。结论：术前血清TSH水平是预测甲状腺结节良恶性的重要指标。     

血清降钙素原测定在ICU感染中的应用研究

目的探讨血清降钙素原测定在ICU患者感染诊断及预测中的应用价值。方法对我院ICU 2011年1月~2012年12月收治的102例患者进行病原学检查,并根据诊断结果,将患者分为感染组和非感染组,同时检测两组患者的血清PCT水平,并比较分析。另外,分别以0.5μg/L和0.2μg/L为阀值,观察不同阀值下血清PCT预测感染发生的灵敏度、特异性、阳性预测值和阴性预测值,以期探寻降钙素原预测细菌感染发生的准确阀值。结果 102例患者中,感染组患者62例,平均血清PCT水平为(4.35±2.33)μg/L;未感染组患者40例,平均血清PCT水平为(1.22±1.02)μg/L。两组患者的血清PCT水平比较差异具有统计学意义(P0.01)。当阀值为0.2μg/L时,血清PCT预测感染发生的灵敏度、特异性、阳性预测值和阴性预测值分别为77.42%、60%、75%、63.16%;当阀值为0.5μg/L时,依次为95.16%、85%、90.77%、91.89%。两个阈值比较,差异具有统计学意义(P0.01)。结论血清降钙素原水平升高可作为诊断ICU感染的重要敏感指标,当血清降钙素原阀值为0.5μg/L左右时,可提高血清PCT预测细菌感染发生的灵敏度、特异性。     

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。     

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.     

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。     

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.     

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.