剪切应力作用下血小板活化反应对血栓形成的影响

目的：通过剪切应力对血小板细胞骨架和细胞内游离钙离子浓度([Ca^2+]i)及血栓形成的影响，探讨物理作用下血小板活化机制。方法：利用锥板式血小板聚集仪、SDS-PAGE方法及Fura-2／AM法观察剪切应力对血小板聚集、细胞支架和胞浆内[Ca^2+]i变化。结果：剪切前肌动蛋白纤维含量为(40．16&;#177;15．03)％，细胞内[Ca^2+]i浓度为(29．88&;#177;8．89)nmol／L，低剪切与高剪切作用1min后肌动蛋白纤维含量分别达(47．42&;#177;18．00)％与(48．62&;#177;18．04)％，而细胞内[Ca^2+]i浓度升高达(57．32&;#177;18．32)nmol／L及(128．28&;#177;56．28)nmol／L，与剪切前相比差异均有显著性意义(P&;lt;0．05或0．01)，此外，钙调蛋白抑制剂阻碍血小板肌动蛋白纤维的形成及血小板聚集。结论：剪切应力作用下血小板发生了肌动蛋白纤维含量及细胞内游离钙水平的增高，并与剪切诱导的血小板聚集存在着平行关系，物理作用对体内血栓形成的机制有助于对血栓形成和一级康复干预的进一步认识。     

剪切应力作用下血小板活化反应对血栓形成的影响

目的:通过剪切应力对血小板细胞骨架和细胞内游离钙离子浓度(犤Ca2+犦i)及血栓形成的影响,探讨物理作用下血小板活化机制。方法:利用锥板式血小板聚集仪、SDS-PAGE方法及Fura-2/AM法观察剪切应力对血小板聚集、细胞支架和胞浆内犤Ca2+犦i变化。结果:剪切前肌动蛋白纤维含量为(40.16±15.03)%,细胞内犤Ca2+犦i浓度为(29.88±8.89)nmol/L,低剪切与高剪切作用1min后肌动蛋白纤维含量分别达(47.42±18.00)%与(48.62±18.04)%,而细胞内犤Ca2+犦i浓度升高达(57.32±18.32)nmol/L及(128.28±56.28)nmol/L,与剪切前相比差异均有显著性意义(P<0.05或0.01),此外,钙调蛋白抑制剂阻碍血小板肌动蛋白纤维的形成及血小板聚集。结论:剪切应力作用下血小板发生了肌动蛋白纤维含量及细胞内游离钙水平的增高,并与剪切诱导的血小板聚集存在着平行关系,物理作用对体内血栓形成的机制有助于对血栓形成和一级康复干预的进一步认识。     

酪氨酸激酶和磷酸酶及蛋白激酶C在As2O3调控NB4细胞和皮层神经元凋亡中的作用

目的　研究蛋白酪氨酸激酶和蛋白酪氨酸磷酸酶及蛋白激酶C(PKC)在三氧化二砷 (As2O3 )调控白血病细胞和人脑皮层神经元凋亡中的作用 ,观察As2 O3 对人脑皮层神经元和白血病细胞的胞浆游离钙 ([Ca2 ]i)浓度的影响。方法　用Fluo 3/AM荧光探针标记人白血病细胞和人脑皮层神经元[Ca2 ]i,激光共聚焦显微镜实时测定不同浓度As2 O3 干预后 [Ca2 ]i的变化并观察蛋白酪氨酸激酶和磷酸酶抑制剂对 [Ca2 ]i变化的影响。磷基转移法测定细胞膜和胞浆的PKC活性。琼脂糖凝胶电泳法观察细胞DNA的片段化。结果　 1μmol /L的As2 O3 使NB4细胞的 [Ca2 ]i明显增高 ,而对人脑皮层神经元 [Ca2 ]i影响不明显。 2 μmol /L以上的As2 O3 引起两种细胞 [Ca2 ]i增高 ,此作用被磷酸酶抑制剂钒酸盐呈浓度依赖性促进 ,被蛋白酪氨酸激酶抑制剂金雀异黄素呈浓度依赖性抑制 ,2 ,5 ,10μmol/L钒酸盐作用 2 4 0s时NB4细胞的 [Ca2 ]i总增加率分别为 (6 .5± 2 .3) % ,(2 1.7± 2 .1) %和 (4 9.2± 2 .5 ) % ;人脑皮层神经元为 (6 .7± 2 .1) % ,(19.4± 2 .5 ) %和 (5 2 .3± 2 .7) % ;2 ,5 ,10 μmol/L金雀异黄素作用 2 4 0s时NB4细胞的总抑制率分别为 (6 .7± 2 .9) % ,(2 5 .6± 2 .5 ) %和 (5 2 .2± 3.5 ) % ;人脑皮层     

Na+/Ca2+交换抑制剂对慢性阻塞性肺疾病患者肺泡巨噬细胞功能的影响

目的观察Na /Ca2 交换抑制剂Benzamil对慢性阻塞性肺疾病(COPD)患者肺泡巨噬细胞(AM)胞浆中游离钙离子(〔Ca2 〕i)浓度及其对生成肿瘤坏死因子-α(TNF-α)、丙二醛(MDA)的影响。方法采用支气管肺泡灌洗、细胞培养和荧光指示剂的方法,测定36例COPD稳定期患者及36例健康体检者AM内〔Ca2 〕i浓度及其生成的TNF-α和MDA含量。结果1COPD组患者AM内〔Ca2 〕i〔(68.26±7.24)nmol/L〕、TNF-α〔(5.74±0.42)ng/L〕和MDA〔(3.77±0.61)μg/L〕水平均较健康对照组〔分别为(60.61±6.26)nmol/L、(2.06±0.20)ng/L、(1.91±0.19)μg/L〕明显增高(P均<0.01);2给予缺氧后,COPD组AM内〔Ca2 〕i浓度〔(168.34±17.58)nmol/L〕、TNF-α〔(9.67±1.01)ng/L〕和MDA〔(11.21±1.01)μg/L〕水平均较刺激前增高(P均<0.01);3先加Benzamil孵育AM再缺氧,可使胞浆内〔Ca2 〕i浓度〔(129.21±14.33)nmol/L〕、TNF-α〔(6.78±0.52)ng/L〕和MDA〔(8.47±0.79)μg/L〕水平均较单纯缺氧时明显减少(P均<0.01)。结论Benzamil可抑制由缺氧引起AM内〔Ca2 〕i浓度增高及其产生的TNF-α、MDA含量;提示通过调节AM激活可抑制TNF-α、MDA的分泌。     

兴奋毒损伤海马神经细胞机制的研究

目的　探讨谷氨酸 (Glutamicacid ,Glu)的神经性兴奋毒损伤作用机制。方法　在体外快速剥离新生大鼠 (0 1天 )双侧海马 ,制成海马神经细胞悬液 ,用Fura 2 /AM负载 ,建立了Fura 2 /AM检测海马神经细胞胞内游离钙离子浓度 ([Ca2 + ]i)的方法 ,并检测Glu兴奋毒对海马神经细胞 [Ca2 + ]i的影响。结果　Fura 2单细胞检测表明 ,静息状态下海马神经细胞 [Ca2 + ]i=2 5 2 .6± 36 .1(nmol/L) ,Glu可使海马神经细胞 [Ca2 + ]i明显升高。大剂量Glu可使 [Ca2 + ]i升高几倍。结论　Glu导致神经细胞损伤的原因与细胞 [Ca2 + ]i超载有关。     

藻酸双酯钠保护血红素所致神经细胞损伤的途径

目的:观察海洋药物提取剂藻酸双酯钠对血红素所致神经细胞损伤的保护作用。方法:实验于1999-01/2000-01在河南医科大学药理实验室完成。体外培养大鼠胚胎皮质神经细胞,血红素组加入100mg/L血红素建立神经细胞血红素损伤模型;正常对照组不加血红素,其余处理同血红素组。藻酸双酯钠组在血红素处理前后24h及处理过程中加入50,100,150mg/L藻酸双酯钠。采用噻唑蓝微量自动比色测定细胞死亡数;采用酶联免疫吸附法测定损伤神经细胞的吸光度值;测定乳酸脱氢酶漏出量、丙二醛含量、超氧化物歧化酶活性;Fura-2负载,以荧光分光光度计测定细胞内游离钙的变化;以碘化丙啶染色,流式细胞仪定量分析细胞凋亡百分率。结果:①噻唑蓝测定显示50,100,150mg/L藻酸双酯钠均可显著减少细胞死亡数;血红素组神经细胞乳酸脱氢酶漏出量高于正常对照组[分别为(1025.20±125.86),(383.41±53.34)kat/g],50,100,150mg/L藻酸双酯钠组乳酸脱氢酶漏出量低于血红素组[分别为(843.50±25.67),(740.15±79.02),(551.44±83.02),(1025.20±125.86)μkat/g]。②血红素组丙二醛含量与正常对照组比较显著增加[分别为(14.9±1.1),(5.1±0.6)μmol/g],超氧化物歧化酶活性显著降低[分别为(9.50±0.08),(31.17±2.83)μkat/g;50,100,150mg/L藻酸双酯钠组丙二醛含量与血红素组比较均显著降低[分别为(11.62±0.50),(10.70±0.37),(8.76±0.78),(14.9±1.1)μmol/g]、超氧化物歧化酶活性显著升高[分别为(16.00±1.67),(22.00±1.00),(24.50±0.83),(9.50±0.08)μkat/g]。③神经细胞损伤后血红素组[Ca2 ]i含量高于正常对照组[分别为(579±39),(145±35)nmol/L,50,100,150mg/L藻酸双酯钠组[Ca2 ]i含量低于血红素组[分别为(432±40),(376±47),(302±64),(579±39)nmol/L],抑制率分别为23%,35%,48%。④50,100,150mg/L藻酸双酯钠组神经细胞平均凋亡率低于血红素组[分别为(25.3±5.3)%,(15.2±4.1)%,(8.9±3.1)%,(36.8±6.5)%]。结论:藻酸双酯钠对血红素所致神经细胞损伤具有显著的保护作用,机制可能与藻酸双酯钠降低[Ca2 ]i累积及抗过氧化作用有关。     

钙在嗜铬细胞瘤细胞缺氧性脑损伤中的作用研究

目的观察缺氧后大鼠肾上腺嗜铬细胞瘤(PC12)细胞内游离钙的浓度(犤Ca2+犦i)、环磷酸腺苷(cAMP)、钙调蛋白(CaM)和钙调蛋白激酶II(Ca2+/CaM-PKII)的变化。方法采用放免技术,从细胞水平进一步观察缺氧对PC12细胞的毒性、细胞内犤Ca2+犦i变化,cAMP、CaM和Ca2+/CaM-PKII的变化。结果缺氧组PC12细胞cAMP、CaM含量在缺氧后24h明显高于正常对照组;Ca2+/CaM-PKII活性明显低于正常对照组。结论犤Ca2+犦i、cAMP、CaM和Ca2+/CaM-PKII在缺氧PC12细胞损伤机制中起了重要的作用。     

急性支气管哮喘患者血小板内游离钙离子的变化与血小板功能的活化

目的通过对哮喘急性发作期患者血小板内游离钙离子浓度([Ca2 ]i)及血小板α-颗粒膜蛋白-140(GMP-140)的检测,探讨其与血小板活化功能的关系及其临床意义。方法选择67例哮喘急性发作期患者(其中轻、中、重度分别为18,21,28例)及40例正常对照者。采用Fura-2/AM标记的荧光法测定静息状态及凝血酶刺激后血小板[Ca2 ]i;ELISA法测定血浆GMP-140含量。结果支气管哮喘急性发作期静息状态血小板[Ca2 ]i及血浆αGMP-140水平均高于缓解期患者及健康对照者,其中以中、重度患者差别显著;而哮喘缓解期与正常对照组几乎无差别。经凝血酶刺激后,各组血小板[Ca2 ]i显著高于缓解期患者及正常对照者。结论哮喘急性发作期血小板[Ca2 ]i升高且与血小板功能活化密切相关。哮喘发作程度愈重,血小板活化程度也就越高。提示哮喘发作期特别是重症哮喘,进行血小板功能检测及应用抗血小板活化药物的必要性。     

Fluo-3荧光微量法测定人红细胞胞浆内游离钙离子浓度

近年来研究表明,高血压病患者血管平滑肌功能异常主要与钙代谢有关,其中细胞内钙离子 (Ca2+ )浓度增加是导致血压升高的主要原因 [1]。血小板内游离钙测定已有较多报道 [2],在血小板的分离过程中易激活胞内花生四烯酸代谢,形成血栓烷A2 等物质,可促进血小板致密小管中储存钙的释放。而测定红细胞 (RBC)中游离钙,可较好地避免人为因素的影响。RBC胞浆钙 (RBCsCa2+ )测定方法有原子吸收光度法测定总钙量 [3],放射同位素 45Ca2+示踪法 [1],但操作繁锁,受条件限制。近来荧光钙结合探针Fluo 3的出现,可直接测定RBC内Ca2+浓度。避免血…     

钙在嗜铬细胞瘤细胞缺氧性脑损伤中的作用研究

目的 观察缺氧后大鼠肾上腺嗜铬细胞瘤（PC12）细胞内游离钙的浓度（[Ca^2 ]i)，环磷酸腺苷（cAMP），钙调蛋白（CaM)和钙调蛋白激酶Ⅱ（Ca^2 /CaM-PKⅡ）。方法 采用放免技术，从细胞水平进一步观察缺氧对PC12细胞的毒性，细胞内[Ca^2 ]i变化，cAMP,CaM和Ca^2／CaM-PKⅡ的。结果 缺氧组PC12细胞cAMP,CaM含量在缺氧后24h明显高于正常对照组：Ca^2 /CaM-PKⅡ活性明显低于正常对照组。结论 [Ca^2 ]i,cAMP,CaM和Ca^2 /CaM-PKⅡ在缺氧PC12细胞损伤机制中起了重要的作用。     

Migraine and genetic and acquired vasculopathies

It is remarkable that migraine is a prominent part of the phenotype of several genetic vasculopathies, including cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL), retinal vasculopathy with cerebral leukodystrophy (RVCL) and hereditary infantile hemiparessis, retinal arteriolar tortuosity and leukoencephalopahty (HIHRATL). The mechanisms by which these genetic vasculopathies give rise to migraine are still unclear. Common genetic susceptibility, increased susceptibility to cortical spreading depression (CSD) and vascular endothelial dysfunction are among the possible explanations. The relation between migraine and acquired vasculopathies such as ischaemic stroke and coronary heart disease has long been established, further supporting a role of the (cerebral) blood vessels in migraine. This review focuses on genetic and acquired vasculopathies associated with migraine. We speculate how genetic and acquired vascular mechanisms might be involved in migraine.     

Fibrinogen and fibrin structure and functions

Fibrinogen molecules are comprised of two sets of disulfide-bridged Aalpha-, Bbeta-, and gamma-chains. Each molecule contains two outer D domains connected to a central E domain by a coiled-coil segment. Fibrin is formed after thrombin cleavage of fibrinopeptide A (FPA) from fibrinogen Aalpha-chains, thus initiating fibrin polymerization. Double-stranded fibrils form through end-to-middle domain (D:E) associations, and concomitant lateral fibril associations and branching create a clot network. Fibrin assembly facilitates intermolecular antiparallel C-terminal alignment of gamma-chain pairs, which are then covalently 'cross-linked' by factor XIII ('plasma protransglutaminase') or XIIIa to form 'gamma-dimers'. In addition to its primary role of providing scaffolding for the intravascular thrombus and also accounting for important clot viscoelastic properties, fibrin(ogen) participates in other biologic functions involving unique binding sites, some of which become exposed as a consequence of fibrin formation. This review provides details about fibrinogen and fibrin structure, and correlates this information with biological functions that include: (i) suppression of plasma factor XIII-mediated cross-linking activity in blood by binding the factor XIII A2B2 complex. (ii) Non-substrate thrombin binding to fibrin, termed antithrombin I (AT-I), which down-regulates thrombin generation in clotting blood. (iii) Tissue-type plasminogen activator (tPA)-stimulated plasminogen activation by fibrin that results from formation of a ternary tPA-plasminogen-fibrin complex. Binding of inhibitors such as alpha2-antiplasmin, plasminogen activator inhibitor-2, lipoprotein(a), or histidine-rich glycoprotein, impairs plasminogen activation. (iv) Enhanced interactions with the extracellular matrix by binding of fibronectin to fibrin(ogen). (v) Molecular and cellular interactions of fibrin beta15-42. This sequence binds to heparin and mediates platelet and endothelial cell spreading, fibroblast proliferation, and capillary tube formation. Interactions between beta15-42 and vascular endothelial (VE)-cadherin, an endothelial cell receptor, also promote capillary tube formation and angiogenesis. These activities are enhanced by binding of growth factors like fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF), and cytokines like interleukin (IL)-1. (vi) Fibrinogen binding to the platelet alpha(IIb)beta3 receptor, which is important for incorporating platelets into a developing thrombus. (vii) Leukocyte binding to fibrin(ogen) via integrin alpha(M)beta2 (Mac-1), which is a high affinity receptor on stimulated monocytes and neutrophils.     

Telemedicine and teleradiology technologies and applications

Summary. Telemedicine and teleradiology hold the key for improving future health care delivery. In this paper we first review current communication and computer technologies used in telemedicine and teleradiology. Five examples in teleradiology applications are given including hospital-integrated picture archiving and communication systems, tele-neuro-imaging, telemammography, university consortium teleradiology service, and teleradiology for second opinion. Parameters important to teleradiology applications like costs, image quality, system reliability, and turn around time are considered. Data security is discussed, including patient confidentiality and image authenticity-which will be a major issue in future teleradiology applications.     

创伤高血糖与感染和MODS早期诊断和干预

本文详细介绍了创伤后血糖应激适度理论,以及高血糖与感染和多器官功能不全综合征的关系;提出涉及胰岛B细胞功能不全的MODS实验诊断新方案和极化液个体化干预新措施,可早期发现创伤MODS、降低感染率及MODS发生率和病死率。     

腹膜后纤维化与肾积水发生关系的临床研究

目的：探讨腹膜后纤维化（RPF）导致肾积水的原因及诊治经验。方法：回顾分析2004年1月—2010年12月24例腹膜后纤维化致肾积水患者的诊治资料。结果：（1）RPF患者常见首发症状为腰背痛或腹痛（69.2%）;（2）红细胞沉降率（ESR）增快和血清IgG4升高最常见。超声检查仅提示上尿路积水。RPF的静脉肾盂造影（IVP）和CT尿路成像（CTU）表现具有特征性。IVP肾盂输尿管显影不良时,CTU能较清晰的显示上尿路影像。CT扫描发现腹膜后软组织肿块9例（37.5%）,优于超声检查;（3）输尿管松解和腹腔化手术治疗22例;行肾切除术1例;行输尿管置双J管术1例。最终确诊为继发性RPF8例,其中4例为术前诊断,3例为术中腹膜后软组织肿块冷冻活检证实,1例为术后病理证实;（4）特发性RPF手术后肾积水均获长期缓解,而继发性RPF的预后取决于原发疾病及其治疗方案。结论：影像学检查是诊断RPF的重要手段,CTU优于超声检查和IVP。输尿管松解和腹腔化手术可以使特发性RPF输尿管梗阻得到长期的缓解,术中对肿块进行冷冻活检有助于鉴别特发性和继发性RPF,及时调整治疗方案。     

探讨儿童慢性顽固性咳嗽与支原体感染的关系及临床治疗观察

目的探讨儿童慢性顽固性咳嗽与肺炎支原体（MP）感染的关系及临床疗效观察。方法采用回顾性研究方法对于现将2005年3月至2008年3月在我院的55例确诊慢性顽固性咳嗽患儿,主要表现为肺炎支原体感染为临床特点进行分析,并进一步临床治疗研究。结果①临床特点：在55例确诊慢性咳嗽的患儿中,以慢性顽固性咳嗽为主要症状。58％（32／55）的病例无肺部体征;②外周血：85％（47／55）的病例外周血变化不大,WBC（4—10）×10 9／L之间,嗜酸性粒细胞增多;③特别检查：47．27％（26／55）肺炎支原体IgM（MP—IgM）抗体阳性,83．64％（46／55）PeR技术检测肺炎支原体特异性DNA;④X光报告为多种形式。结论肺炎支原体（MP）感染是引起儿童慢性顽固性咳嗽的病因之一,对儿童慢性咳嗽,特别是顽固性咳嗽的诊治中应更加重视。     

Acetaminophen and acetylcysteine dose and duration: Past,present and future

Abstract

Acetylcysteine has been utilized successfully in the treatment of acetaminophen overdose since the 1970s. Although prospective trials as to efficacy and safety of acetylcysteine were conducted, there were no randomized controlled trials. This commentary addresses the reasons for this, and the background to choice of dose of acetylcysteine utilized in the oral and IV dosing regimens. Nomograms to predict possible hepatotoxicity based upon time of ingestion of acetaminophen were developed from a relatively arbitrary definition of toxicity as an aspartate aminotransferase/alanine aminotransferase (ALT/AST) greater than 1000 IU/L. While these have proved generally useful, patients still continue to develop hepatic damage after acetaminophen overdose, particularly if they present late after ingestion. The optimum management of these patients remains unclear, and one area of uncertainty is the dose and duration of acetylcysteine in various circumstances. This article discusses the issues that need to be elucidated to better target changes in acetylcysteine dose. The potential for measurements of other markers to improve treatment selection is the subject of further research.     

Physician and Nurse Practitioner Teamwork and Job Satisfaction: Gender and Profession

Designing interprofessional primary care teams composed of physicians and nurse practitioners (NPs) is a national priority. We assessed how profession and gender affect teamwork and job satisfaction among primary care physicians and NPs by using survey data from 186 physicians and 398 NPs practicing in New York State. Our regression models show profession (NP vs physician) moderates the associations of gender with teamwork and job satisfaction. Among NPs, men had higher job satisfaction than women. Among physicians, women had higher job satisfaction than men. Our results can benefit interprofessional primary care teams to optimize their professional and gender mix.