Type IIB Tampa: a variant of von Willebrand disease with chronic thrombocytopenia, circulating platelet aggregates, and spontaneous platelet aggregation

Type IIB von Willebrand disease is characterized by enhanced ristocetin- induced platelet aggregation and absence of large von Willebrand factor multimers from plasma. An alteration of the von Willebrand factor molecule resulting in increased reactivity with platelets appears to be the basis for these abnormalities. We have now identified a new variant of type IIB von Willebrand disease in a family in which the four affected members also have chronic thrombocytopenia, in vivo platelet aggregate formation, and spontaneous platelet aggregation in vitro. In spite of repeatedly prolonged bleeding times and persistent thrombocytopenia, their bleeding diathesis is only moderate.     

角质形成细胞的培养及其表皮生长因子受体表达

目的:在成功分离人皮肤角质形成细胞的基础上,观察表皮生长因子受体在人皮肤角质形成细胞中的表达情况。方法:实验于2006-3/10在北京大学深圳医院中心实验室进行。采用dispase Ⅱ-trypsin两步消化法获取表皮基底层细胞,用小鼠皮肤成纤维母细胞滋养层和黄素腺嘌呤二核苷酸培养液进行培养。小鼠皮肤成纤维母细胞的预处理:向对数生长期的小鼠皮肤成纤维母细胞培养液中加入丝裂霉素C至终浓度为4mg/L,37℃下培养4h,弃去培养液,用D-Hank’s液洗3次,加入浓度为0.25g/L的胰蛋白酶消化,分离出细胞,离心(200g,5min),用黄素腺嘌呤二核苷酸培养液悬浮细胞,计数,以5.0×104/cm2的密度种于培养皿内,37℃、体积分数0.05的CO2培养箱下培养。角质形成细胞的培养:将分离的角质形成细胞悬浮在黄素腺嘌呤二核苷酸培养液中,以2.0×104/cm2的密度接种在前1天经丝裂霉素C处理的小鼠皮肤成纤维母细胞滋养层上,37℃、体积分数0.05的CO2培养箱下培养。24h换液,以后每3d换1次液。采用免疫细胞化学的方法检测表皮生长因子受体的表达,采用复合逆转录聚合酶链反应检测角质形成细胞中表皮生长因子受体mRNA的表达。结果:采用dispaseⅡ消化法分离了真皮和表皮,获得较多的角质形成细胞,可以避免真皮成纤维细胞的污染。人皮肤角质形成细胞在黄素腺嘌呤二核苷酸培养液中培养5d可见明显的集落,约10d可长满单层。免疫细胞化学显示表皮生长因子受体在细胞表面有明显的表达,复合逆转录聚合酶链反应显示表皮生长因子受体mRNA有明显的表达。结论:用小鼠皮肤成纤维母细胞滋养层和黄素腺嘌呤二核苷酸培养液可以较好地培养原代人皮肤角质形成细胞,表皮生长因子受体在细胞表面有明显的表达,这些结果为与表皮生长因子受体相关的皮肤病(如银屑病)的研究奠定了基础。     

B超诊断老年性白内障及合并症价值

０引言老年性白内障严重影响着老年人的生活质量．手术是根治本病的最佳方法．现将我院１９９８－０１～１９９８－１１经Ｂ超检查并经手术证实的１２９例,共２５８只眼,２２３只老年性白内障的结果及声像图特点报告如下．旨在探讨Ｂ超在诊断该病中的应用价值及对手术的...     

甜茶树甜味成分研究

从甜茶树[Cyclocarya paliurus(Batal.)Iljinskaya]中分离得到4个(Ⅰ～Ⅳ)有强甜味的化合物。根据理化性质和光谱数据,鉴定化合物Ⅰ的结构为20,24-环氧-达玛烷-(3β、12β、24R)-120-O-α-L-吡喃鼠李糖基-25-羟基-3-O-α-(5’-O-乙酰基)-L-呋喃阿拉伯糖甙,为一新的天然产物,命名为甜茶树甙A(cyclocarioside A)。     

阿霉素脂质体肝动脉栓塞治疗大鼠肝癌的药效学研究

目的:观察阿霉素脂质体(Lip-ADM)碘油乳剂肝动脉栓塞治疗大鼠W256肝癌模型的疗效,并与阿霉素水溶液(ADM)及阿霉素加空白脂质体(Lip ADM)相比较。方法:建立大鼠移植性W256肝癌模型并随机分为四组,经肝动脉分别灌注生理盐水,ADM碘油乳剂,游离ADM 空白脂质体及Lip-ADM碘油乳剂,用高效液相色谱测定阿霉素在各器官中的含量。结果:与ADM及ADM 空白脂质体组相比:Lip-ADM组对肿瘤生长的抑制明显增加(P<0.05),治疗后的大鼠生存期亦明显延长(P<0.05),阿霉素在体内的分布以肝、脾组织为主。结论:阿霉素脂质体经肝动脉栓塞化疗可明显降低阿霉素毒副作用,提高治疗效果。     

胶原-生物衍生骨材料与兔成骨细胞的相容性及其体外附着特点

目的:观察胶原-生物衍生骨复合材料与兔成骨细胞的相容性及体外附着规律,为进一步的体内实验提供参考数据。方法:实验于2003-10/2005-02在华西医科大学组织工程实验室进行。①材料制备:新鲜捐献骨(人),经脱脂、脱蛋白等工艺制成单纯生物衍生骨材料,以Ⅰ型胶原通过真空吸附法修饰单纯生物衍生骨材料表面,构建出胶原生物衍生骨材料。②实验方法:将体外培养的兔骨膜成骨细胞分别复合于单纯生物衍生骨材料和胶原生物衍生骨材料,共同培养7d。③观察指标:分别于培养第1,3,5和7天取材,扫描电镜观察成骨细胞形态及附着情况;用紫外/荧光/可见光高效分析仪测定成骨细胞产生的碱性磷酸酶活性;MTT检测成骨细胞增殖情况;用流式细胞仪检测兔成骨细胞的细胞周期、DNA含量及倍体水平。结果:①扫描电镜结果:胶原生物衍生骨材料组成骨细胞黏附和增殖优于生物衍生骨材料组。②碱性磷酸酶活性:生物衍生骨材料组低于胶原生物衍生骨材料组(0.019±0.003,0.038±0.004,P<0.05)。③细胞增殖情况:在培养第1,3,5,7天胶原生物衍生骨材料组成骨细胞A值均高于生物衍生骨材料组(P<0.05)。④流式细胞检测生物衍生骨材料、胶原生物衍生骨材料对兔成骨细胞的细胞周期影响不大,各组细胞皆为正常的二倍体细胞,未见异倍体细胞形成,胶原修饰后无细胞毒性。结论:以单纯生物衍生骨作为载体,其表面经胶原修饰后的复合材料与成骨细胞有良好的细胞相容性,无细胞毒性。     

Further characterization of platelet-type von Willebrand's disease in Japan

We studied four patients who showed aggregation of platelets in platelet-rich plasma at lower concentrations of ristocetin than those required for normal platelet-rich plasma and who demonstrated an increased capacity of the platelets to bind normal von Willebrand factor. The four patients were from two Japanese families. Platelets from one family aggregated spontaneously in vitro, and platelets from both families aggregated upon the addition of normal plasma and cryoprecipitate, in the absence of ristocetin or other agonists. Analysis of the multimeric composition of von Willebrand factor by sodium dodecyl sulfate-agarose gel electrophoresis revealed a decrease in large multimers or a decrease in both large and intermediate multimers in plasma, but normal multimers in platelets. 1-Deamino-[8-D- arginine]-vasopressin caused by an immediate appearance of larger multimers in plasma, followed by the rapid disappearance of these multimers from circulating plasma. Analysis of platelet membrane glycoproteins from the patients showed that there were two distinct bands in the glycoprotein I region; one migrated in a slower region and the other in a faster region than normal glycoprotein Ib. We suggest that the platelet receptor abnormality in these patients is related to this abnormality of glycoprotein Ib.     

Real-time analysis of shear-dependent thrombus formation and its blockade by inhibitors of von Willebrand factor binding to platelets

Two likely mechanisms for the initiation of arterial platelet thrombus formation under conditions of elevated fluid shear stresses are: (1) excessive adhesion and aggregation of platelets from rapidly flowing blood onto the exposed sub-endothelium of injured, atherosclerotic arteries; or (2) direct, fluid shear stress-induced aggregation of platelets in constricted arteries with intact endothelial cells. Mechanism (1) was simulated using a parallel plate flow chamber, fibrillar collagen type I-coated slides, and mepacrine-labeled (fluorescent) platelets in whole blood anticoagulated with citrate, hirudin, unfractionated porcine heparin, or low molecular weight heparin flowing for 1 to 2 minutes at wall shear rates of 100 to 3,000 seconds-1 (4 to 120 dynes/cm2). The precise sequence of interactions among von Willebrand factor (vWF), glycoprotein (GP)Ib, and GPIIb-IIIa during platelet adhesion and subsequent aggregation were resolved by direct real-time observation using a computerized epifluorescence video microscopy system. Adhesion at high shear rates was the result of the adsorption of large vWF multimers onto collagen and the binding of platelet GPIb to the insolubilized vWF. Aggregation occurred subsequently and required the binding of ligands, including vWF via its RGD binding domain, to GPIIb-IIIa. Mechanism (2) was modeled by producing shear stresses of 90 to 180 dynes/cm2 in a rotational cone and plate viscometer, which aggregates platelets from platelet-rich- plasma (PRP) anti-coagulated with citrate, hirudin, or either type of heparin in reactions that require large vWF multimers, Ca2+, adenosine diphosphate, and both GPIb and GPIIb-IIIa. Both vWF-mediated shear- aggregation in PRP and platelet-collagen adhesion in flowing whole blood (anticoagulated with citrate and hirudin) are inhibited by two potentially useful anti-arterial thrombotic agents: polymeric aurin tricarboxylic acid (ATA; 28.5 to 114 micrograms/mL), which binds to vWF and inhibits its attachment of GPIb, and a recombinant vWF fragment (rvWF445-733; 30 to 200 micrograms/mL) that binds to platelet GPIb (in the absence of any modulator) and blocks attachment of vWF multimers. Unfractionated heparin, but not low molecular weight heparin, apparently binds to rvWF445-733 and counteracts the inhibitory effects of the vWF fragment in vitro on shear-aggregation and platelet-collagen adhesion.