Circulating serotonin in vertebrates

The role of circulating serotonin is unclear and whether or not serotonin is present in the blood of non-mammalian species is not known. This study provides the first evidence for the presence of serotonin in thrombocytes of birds and three reptilian species, the endothermic leatherback sea turtle, the green sea turtle and the partially endothermic American alligator. Thrombocytes from a fresh water turtle, American bullfrog, Yellowfin tuna, and Chinook salmon did not contain serotonin. Serotonin is a vasoactive substance that regulates skin blood flow, a major mechanism for endothermic body temperature regulation, which could explain why circulating serotonin is present in warm-blooded species. The temperature sensitivity of human blood platelets with concomitant changes in serotonin content further supports a link between circulating serotonin and thermoregulation. Phylogenetic comparison of the presence of circulating serotonin indicated an evolutionary divergence within reptilian species that might coincide with the emergence of endothermy.Received 2 April 2005; received after revision 15 May 2005; accepted 15 June 2005     

手术前后血管内皮生长因子、血小板活化因子水平与非小细胞肺癌的关系

目的：探讨非小细胞肺癌患者手术前、后血清血管内皮生长因子（VEGF）、外周血血小板活化标志物的动态变化规律及其与非小细胞肺癌（NSCLC）的关系。方法：用EUSA法检测120例非小细胞肺癌患者手术前、后血清VEGF水平和60例健康体检者VEGF水平；同时用流式细胞术（FCM）检测其外周血血小板活化标志物水平。结果：①NSCLC患者手术前、后VEGF水平和血小板活化标志物水平均显著高于正常对照组（P〈0．01）；②NSCLC患者手术后第7天血清VEGF水平显著高于术前和术后第1天水平（P〈0．01）；而血小板活化标志粉水平则相反；③NSCLC患者血清VEGF和外周血血小板活化标志物水平与有无淋巴结转移和TNM分期有密切关系（P〈0．05）。结论：NSCLC患者血清中VEGF和外周血血小板活化标志物水平都升高。且与NSCLC的分期有密切关系．它们可作为动态检测NSCLC患者病情进展、判断预后的拳考指标。     

SiCpl-BAS复合材料的显微组织与力学性能

用热压烧结法工艺制备碳化硅片晶增强BAS（BaOAl2O32SiO2)玻璃陶瓷基复合材料（SiCpl-BAS)，并对其组织结构与力学性能进行了研究，结果表明，当碳化硅片晶体积分数达到0．30时，SiCpl-BAS复合材料的断裂韧性和抗弯强度分别从纯基体的100．3MPa和1．49MPa.m^1/2，提高到181．0MPa和3．20MPa.m^1／2，主要的增强增韧机理为裂纹的偏转,分岔和片晶的拔出。     

家猫妊娠早期血小板数量变化的研究

雌猫受精后,在第2天外周血小板数量即明显低于受精前和未孕的正常猫(P<0.01).在受精后第7—8天将受精卵从输卵管或子宫冲出后,7天内又回升到受精前水平.由此可见,外周血小板数量减少与受精卵在生殖管道的存在有关.假孕猫经胚胎移植后,第2天血小板数目也明显降低于移植前.因此,外周血小板计数可望成为检测猫胚胎移植成效的简便方法。     

晚期头颈恶性肿瘤组织含促血小板聚集物

为探讨头颈恶性肿瘤组织提取液是否含有聚集血小板的物质，将15例头颈恶性肿瘤和14例非恶性肿瘤组织匀浆取组织提取液，分别致聚于头颈恶性肿瘤21例。非肿瘤，非恶性肿瘤33例及健康人16例的血小板，发现，头颈恶性肿瘤组织提取液致聚于头颈恶性肿瘤21例，非肿瘤，非恶性肿瘤33例及健康人16例血小板，发现，头颈恶性肿瘤组织提取液致聚的阳性率比非恶性头颈肿瘤组织提取液致聚的高；头颈恶性肿瘤组织提取液对血小板的聚集作用随病期进展而增强。头颈部恶性肿瘤病人的血小板易受组织提取液激素，其血小板最大聚集率随病期进展的增强，表明，晚期头颈恶性肿瘤组织含促血小板聚集物。这可能是直接引起恶性肿瘤机体血小板聚集增强的原因之一。     

Type I phosphoinositide 3-kinases: potential antithrombotic targets?

Arterial thrombosis is the single most common cause of death and disability in industrialized societies and is the primary pathogenic mechanism underlying acute myocardial infarction and ischemic stroke. Platelets play a central role in this process, and as a consequence, a great deal of effort has gone into identifying the mechanisms regulating the adhesive function of platelets. Platelet adhesion is controlled by intracellular signaling pathways, with growing evidence for a major role for phosphoinositide 3-kinases (PI3Ks) in this process. Platelets express all type I PI3K isoforms, including p110α, p110β, p110δ and p110γ, with recent evidence suggesting important roles for p110γ and p110β in regulating distinct phases of the platelet activation process. Deficiency of p110 γ or inhibition of p110β produces a marked defect in arterial thrombosis without a corresponding increase in bleeding time, raising the possibility that inhibition of one or more PI3K isoforms may represent an effective antithrombotic approach. Received 3 January 2006; received after revision 20 February 2006; accepted 20 February 2006     

芪丹天胶囊对老年血瘀大鼠血小板聚集功能及血浆TXB2、6-ketO-PGF1a含量的影响

目的探讨芪丹天胶囊对血小板聚集功能的影响及作用机理.方法以老年雄性大鼠为血瘀模型,采用血小板聚集法和放免法观察芪丹天胶囊对血小板聚集功能及血浆TXB2、6-keto PGFla 含量的影响.结果芪丹天胶囊能明显抑制ADP诱导的血小板聚集,降低血浆中TXB2的含量及TXB2/6-keto-PGFla 的比值.结论芪丹天胶囊具有良好的抑制血小板聚集作用,其作用机理与降低TXB2有关.     

硫化氢拮抗同型半胱氨酸刺激血小板聚集作用

为观察硫化氢(H2S)对同型半胱氨酸(HCY)刺激血小板聚集的影响及机制,在HCY刺激腺苷二磷酸(ADP)诱导的血小板聚集模型上加入不同浓度H2S干预,采用Born's法测定血小板聚集率,Greiss法测定血小板孵育液中亚硝酸盐(NO2-)含量.结果表明:H2S呈浓度依赖的抑制HCY刺激ADP诱导的血小板聚集,显著增加血小板NO释放.Person相关分析,H2S拮抗HCY促血小板聚集作用与NO生成呈负相关(r2=-0.438 7,P＜0.01).由此可见,H2S可拮抗HCY对血小板的效应,其机制可能与改善血小板NO释放有关.     

反复输血患者血小板相关抗体检测及临床意义

为探求血小板相关抗体的产生规律,评价血小板相关抗体筛查的临床意义,对解放军总医院43例反复输注血小板成分的患者采用ELISA方法进行HLA相关抗体筛查。8例结果为阳性,阳性率为18．6％。8例阳性患者的血小板输注次数均在20次以上,说明血小板相关抗体产生几率随着输注次数的增加而增高,选择适当时机进行血小板相关抗体筛查,根据抗体产生情况决定配型与否,既降低医疗成本,又能提高临床输注疗效。