Sphingosylphosphorylcholine,a naturally occurring lipid mediator,inhibits human platelet function

1 The lysophospholipids, lysophosphatidic acid and sphingosine 1-phosphate, have been reported to activate platelets. Here we examined effects of the naturally occurring related sphingosylphosphorylcholine (SPC) on human platelet function. 2 Platelet activation was determined as aggregation, elevation of intracellular Ca(2+) concentrations, surface expression of P-selectin, GP 53, and GP IIb/IIIa neoepitope PAC-1, and of fibrinogen binding to the platelet surface. 3 Platelets were activated by ADP (5 and 20 micro M), the thrombin receptor-activating peptide TRAP-6 (5 and 20 micro M), the thromboxane A(2) mimetic U-46619 (1 micro M) and collagen (20 and 50 micro g ml(-1)) but not by SPC (up to 20 micro M). 4 SPC concentration-dependently (IC(50) approximately 1-10 micro M) inhibited activation of washed human platelets in response to all of the above agonists, with almost complete inhibition occurring at 20 micro M SPC. 5 The SPC stereoisomers, D-erythro SPC and L-threo SPC, exhibited similar concentration-response curves in inhibiting 20 micro M ADP-induced platelet aggregation, suggesting that SPC did not act via specific lysophospholipid receptors. 6 Although SPC slightly activated platelet protein kinase A (as assessed by VASP phosphorylation), this effect could not explain the marked platelet inhibition. Possible protein kinase C inhibition also did not explain the inhibition of platelet activation by SPC. On the other hand, SPC suppressed agonist-induced Ca(2+) mobilization and phospholipase C stimulation. 7 These results indicate that the lysophospholipid SPC is an effective inhibitor of human platelet activation, apparently primarily by uncoupling agonist-activated receptors from their effectors.     

Rippling muscle disease: evidence for phenotypic and genetic heterogeneity

We describe the clinical features of a family with rippling muscle disease. Muscle stiffness and myalgia were the most prominent symptoms. Muscle rippling, although distinctive, was present in only 6 of the 11 affected family members, whereas persistent muscle contraction to muscle percussion was present in all affected adults. Although this persistent contraction resembled percussion myotonia, it was electrically silent and is therefore more aptly called "percussion contracture." We also observed two clinical features not emphasized in previously reported kindreds: mild but asymptomatic weakness of face or proximal muscles was present in 5 of 11 affected members, and 5 individuals also complained of toe walking after a prolonged period of inactivity, reflecting the disproportionate involvement of the calf muscles. The pedigree suggested autosomal dominant inheritance. Our linkage analysis excluded the region on chromosome 1q identified in a previous linkage study.     

纳米级与微米级二氧化硅粉尘对小鼠胚胎毒性的比较研究

目的比较研究纳米级(nm-)与微米级二氧化硅粉尘(μm-SiO2)对小鼠胚胎的影响,并观察胚胎Connexin32(Cx32)和Cx40基因有无点突变改变。方法5个实验组(零剂量粉尘组、μm-SiO250mg/m3组、μm-SiO2200mg/m3组、nm-SiO250mg/m3组、nm-SiO2200mg/m3组)共25只雌性小鼠,妊娠0日(E0)至E17日连续呼吸道染尘,观察妊娠期间母鼠体重变化,E18日取出胚胎,观察胚胎发育情况,并采用常规聚合酶链式反应(PCR)、聚合酶链式反应-单链构像多态性(PCR-SSCP)技术对胚胎的Cx32和Cx40基因进行点突变检测。结果E18日,各染尘组的母鼠体重均显著低于对照组;各染尘组的胚胎数、活胎数、胚胎体重显著低于对照组,nm-SiO2200mg/m3组活胎数显著低于nm-SiO250mg/m3组和μm-SiO2200mg/m3组,nm-SiO2200mg/m3组胚胎体重显著低于μm-SiO2200mg/m3组;nm-SiO2200mg/m3组死胎率和吸收胎率均显著高于对照组。Cx32和Cx40基因经检测未发现有突变者。结论SiO2粉尘具有小鼠胚胎毒性,微米级粒子粒径改变为纳米级后,毒性作用增强,且纳米级SiO2粉尘对小鼠胚胎有致死作用。两种粒径的二氧化硅粉体均未发现有致Cx32和Cx40基因点突变。     

非小细胞肺癌神经内分泌分化的免疫组化诊断

目的： 探讨非小细胞肺癌神经内分泌分化的免疫组化诊断。方法： 选择三种神经内分泌共同标记ＣＧＡ、ＳＹＮ、ＮＣＮＭ, 应用免疫组化ＬＳＡＢ 法, 观察它们在ＮＳＣＬＣ 中的表达。结果： 在１６３ 例ＮＳＣＬＣ 中, １８ 例（１１－０４ ％ ） 表达ＣＧＡ,６３ 例（３８－６５ ％ ） 表达ＳＹＮ,４０ 例（２４－５４ ％ ） 表达ＮＣＡＭ 。７７ 例（４７－２４ ％ ） ＮＳＣＬＣ 至少有１ 种ＮＥ 标记表达,其中４０ 例只表达１ 种标记,３０ 例表达２ 种标记,仅７ 例３ 种标记均表达。３ 种标记表达彼此相关（ Ｐ＜０－００５） ,但存在差异（ Ｐ＜ ０－００５） 。与腺癌相比,腺鳞癌、鳞癌、大细胞癌染色阳性率较低。结论：选择３ 种ＮＥ 标记可以检测出ＮＳＣＬＣ 的ＮＥ 分化, 但不能以某一种标记的表达与否作为ＮＳＣＬＣ 的ＮＥ 分化诊断, 应联合检测以至少２ 种标记表达定义为ＮＥ 分化,在不同类型的ＮＳＣＬＣ 中腺癌更易出现ＮＥ 分化。     

高温作业工人VB1,VB2,Vc丢失量的研究

本文对高温作业工人几种水溶性维生素的代谢情况进行研究。VB_1、VB_2、VC由汗、尿中丢失量分别占摄入量的22.11%,26.77%和6.21%。由汗丢失的VB_1、VB_2分别是尿的1.4倍和1.8倍,是高温作业工人的主要丢失途径。汗中VB_1、VB_2、VC的浓度分别为0.059±0.037μg/ml,0.049±0.023μg/ml,0.390±0.211μg/ml。汗中水溶性维生素的浓度可能受机体营养水平的影响。本文结果可为高温作业工人维生素的补充提供理论依据。     

Sensitivity and resistance towards isoliquiritigenin, doxorubicin and methotrexate in T cell acute lymphoblastic leukaemia cell lines by pharmacogenomics

Co-ordinated electrical activation of the heart is maintained by intercellular coupling of cardiomyocytes via gap junctional channels located in the intercalated disks. These channels consist of two hexameric hemichannels, docked to each other, provided by either of the adjacent cells. Thus, a complete gap junction channel is made from 12 protein subunits, the connexins. While 21 isoforms of connexins are presently known, cardiomyocytes typically are coupled by Cx43 (most abundant), Cx40 or Cx45. Some years ago, antiarrhythmic peptides were discovered and synthesised, which were shown to increase macroscopic gap junction conductance (electrical coupling) and enhance dye transfer (metabolic coupling). The lead substance of these peptides is AAP10 (H-Gly-Ala-Gly-Hyp-Pro-Tyr-CONH₂), a peptide with a horseshoe-like spatial structure as became evident from two-dimensional nuclear magnetic resonance studies. A stable d-amino-acid derivative of AAP10, rotigaptide, as well as a non-peptide analogue, gap-134, has been developed in recent years. Antiarrhythmic peptides act on Cx43 and Cx45 gap junctions but not on Cx40 channels. AAP10 has been shown to enhance intercellular communication in rat, rabbit and human cardiomyocytes. Antiarrhythmic peptides are effective against ventricular tachyarrhythmias, such as late ischaemic (type IB) ventricular fibrillation, CaCl₂ or aconitine-induced arrhythmia. Interestingly, the effect of antiarrhythmic peptides is higher in partially uncoupled cells and was shown to be related to maintained Cx43 phosphorylation, while arrhythmogenic conditions like ischaemia result in Cx43 dephosphorylation and intercellular decoupling. It is still a matter of debate whether these drugs also act against atrial fibrillation. The present review outlines the development of this group of peptides and derivatives, their mode of action and molecular mechanisms, and discusses their possible therapeutic potential.     

假性腰椎滑脱发生年龄与性别关系的研究

目的：作者分析４７３例腰椎假性滑脱的病例，旨在了解其发病年龄与性别的关系。方法：收集因腰腿痛患者的Ｘ线检查共５４２４例。结果：发现腰椎假性滑脱４７３例，其中男１０７例，女３６６例，５１￣７０岁３３０例，结论：在４０岁以上人群中，腰椎假性滑脱的发病率随年龄的增长而增加，女性发生率明显高于男性，而高龄患者腰椎假性滑脱发生率的性别２差异有所缩小，不随的增长而扩大。     

毛细管柱气相色谱法测定水样中硝基氯苯类化合物

目的：建立水样中硝基氯苯类化合物毛细管柱测定方法。方法：利用环己烷萃取水样中硝基氯苯类化合物，经气相色谱毛细管柱分离后用标准曲线法进行定量分析。结果：此方法简便、快速，检测范围较宽（0.015-0.20μg/ml），回收率较好（87.4%-106%），相对标准偏差小于6%。结论：方法适合对水样中硝基氯苯类化合物进行定性和定量分析。     

催化光度法测头发中铁的含量

目的探讨催化光度法测人头发和天然水中铁含量的测定条件及动力学条件。方法建立Fe(Ⅲ)-H2O2-HSN催化反应体系。以lgA0/Ai值对浓度C作标准曲线图,求出发中Fe(Ⅲ)浓度,并与原子吸收法的测定结果比较,进行相关统计分析。结果本法与原子吸收法所测定结果基本一致。测定范围在0.005~0.035mg/L,检测限为6.3×10-7g/L。结论本法应用于人体发样及天然水中铁的测定,灵敏度高,选择性好,操作简单易行,结果满意。     

硬膜外阻滞剖宫产术中输液对产妇肺泡--动脉血氧分压差的影响

目的探讨硬膜外阻滞剖宫产术中以不同速度静脉输入晶体液和胶体液对产妇肺泡-动脉血氧分压差(A-aDO2)的影响.方法选硬膜外阻滞下行择期剖宫产术的产妇80例.麻醉开始至胎儿娩出间期(I-DI)以四种不同速度(10,20,25和30ml·kg-1·h-1)静脉输入两种不同液体(血定安和乳酸钠林格氏液),并据此将产妇平均分为G(血定安)、R(乳酸钠林格氏液)两组和a,b,c,d四个亚组.于麻醉前及术中取胎儿时采产妇足背动脉血各2ml,胎儿娩出时采脐静脉血2ml,测定血气值和产妇的A-aDO2,并评定新生儿1 min Apgar评分.每亚组随机选5例行CVP监测.结果产妇术前和术中的PaO2和PaCO2、脐静脉血的PO2和PCO2以及新生儿1 min Apgar评分各亚组间差异无统计学意义.CVP值两组各对应亚组间相比差异也无统计学意义,并且都在正常值范围内.Rd亚组术中A-aDO2值(22±8.24mmHg)显著高于Ra(16±7.44mmHg)和Rb(15±10.67mmHg)亚组.结论硬膜外阻滞剖宫产术中输入晶体液速度达30 ml·kg-1·h-1时可使产妇A-aDO2显著增加,而对新生儿脐带血气值和1min Apgar评分未产生明显影响.