Bleeding Complications in Antiplatelet Therapy

Antipatelet therapy paly a vital role in preventing atherothrombotic events in patients with coronary artery disease and in those underging revascularization procedures.How,the therapy may occur at the expense of increase risk of bleeding.With a stronger antiplatelet treatment in clinical application,the risk of bleeding causedby antiplatelet agents has become a new and important     

Heparin microparticle effects on presentation and bioactivity of bone morphogenetic protein-2

Biomaterials capable of providing localized and sustained presentation of bioactive proteins are critical for effective therapeutic growth factor delivery. However, current biomaterial delivery vehicles commonly suffer from limitations that can result in low retention of growth factors at the site of interest or adversely affect growth factor bioactivity. Heparin, a highly sulfated glycosaminoglycan, is an attractive growth factor delivery vehicle due to its ability to reversibly bind positively charged proteins, provide sustained delivery, and maintain protein bioactivity. This study describes the fabrication and characterization of heparin methacrylamide (HMAm) microparticles for recombinant growth factor delivery. HMAm microparticles were shown to efficiently bind several heparin-binding growth factors (e.g. bone morphogenetic protein-2 (BMP-2), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (FGF-2)), including a wide range of BMP-2 concentrations that exceeds the maximum binding capacity of other common growth factor delivery vehicles, such as gelatin. BMP-2 bioactivity was assessed on the basis of alkaline phosphatase (ALP) activity induced in skeletal myoblasts (C2C12). Microparticles loaded with BMP-2 stimulated comparable C2C12 ALP activity to soluble BMP-2 treatment, indicating that BMP-2-loaded microparticles retain bioactivity and potently elicit a functional cell response. In summary, our results suggest that heparin microparticles stably retain large amounts of bioactive BMP-2 for prolonged periods of time, and that presentation of BMP-2 via heparin microparticles can elicit cell responses comparable to soluble BMP-2 treatment. Consequently, heparin microparticles present an effective method of delivering and spatially retaining growth factors that could be used in a variety of systems to enable directed induction of cell fates and tissue regeneration.     

不同抗凝剂对肝移植受者FK506血药浓度测定的影响及临床意义

目的探讨不同抗凝剂对肝移植受者他克莫司（FK506）血药浓度测定的影响及临床意义。方法采集肝移植受者静脉全血34份,使用乙二胺四乙酸二钾（EDTA-K2）、枸橼酸钠和肝素锂抗凝剂分别抗凝同一份血样本,在IMx型免疫分析仪上用微粒子酶免疫分析法（MEIA）测定FK506血药浓度。结果肝素锂组与EDTA组差异无统计学意义（P=0.660）,呈正相关（r=0.982 8）。枸橼酸钠组与EDTA组差异有统计学意义（P=0.000）,呈正相关（r=0.961 3）。枸橼酸钠组与肝素锂组差异有统计学意义（P=0.000）,呈正相关（r=0.939 8）。结论肝素锂组与EDTA组几乎无偏差,但是枸橼酸钠组分别与EDTA组和肝素锂组存在一定程度的负偏差。枸橼酸钠对MEIA测定FK506血药浓度有一定的影响,应优先考虑EDTA或肝素锂抗凝剂采集全血样本。     

鳞状上皮细胞癌抗原监测宫颈鳞癌的临床价值

 目的　探讨鳞状上皮细胞癌抗原在监测宫颈鳞癌中的临床价值。方法　用微粒子酶免分析技术对 116例宫颈鳞癌治疗前后进行SCC测定。结果　SCC在宫颈鳞癌中的敏感性为 73.2 8% ,特异性为95 .10 %。SCC阳性率在宫颈鳞癌大细胞角化型及非角化型中较高 ,在小细胞型中较低。并且随着宫颈癌临床分期的升高而增加。在根治性治疗后SCC阳性者均转阴性。结论　SCC是宫颈鳞癌较好的一种肿瘤标记物。在宫颈鳞癌的辅助诊断 ,治疗效果的判断 ,监测疾病状态中有一定价值。     

软骨细胞与异体软骨微粒脱细胞基质体外相容性的研究

目的探索以异体软骨微粒脱细胞基质为支架构建组织工程化软骨。方法多步骤酶法将绵羊关节软骨制成微粒脱细胞基质,行大体、光镜(苏木素伊红、胶原、甲苯胺蓝染色)、扫描电镜观察,同时测定微粒的胶原、氨基葡聚糖、DNA含量。异体绵羊关节软骨细胞分离、体外扩增,并与软骨微粒脱细胞基质混合体外培养0～35d,倒置显微镜及扫描、透射电镜观察,同时测定羟脯氨酸,氨基葡聚糖,DNA含量及细胞黏附率。结果软骨微粒脱细胞基质只含有基质成分,直径0.100～0.154mm,胶原,氨基葡聚糖及DNA含量分别为204.4±3.1μg/mg,18.3±2.0μg/mg和0.042±0.013μg/mg。异体软骨细胞紧紧围绕于异体软骨微粒脱细胞基质四周,二者形成的复合物中胶原、氨基葡聚糖及DNA含量于第7d与0d相比具有统计学意义(P<0.05),分别与14d(胶原、DNA)和21d(氨基葡聚糖)达高峰,随后维持在高水平。细胞黏附率为92%。结论软骨细胞与异体软骨微粒脱细胞基质有良好的生物相容性,为组织工程方法再造软骨提供又一支架材料。     

Effect of maternal antibody on immunogenicity of hepatitis A vaccine in infants

OBJECTIVE: To determine the effect of maternal antibody on hepatitis A vaccine immunogenicity in infants.Study design Infants of mothers negative for antibody to hepatitis A virus (anti-HAV; group 1) were administered hepatitis A vaccine at 2, 4, and 6 months of age, and infants of anti-HAV-positive mothers were randomized to receive either hepatitis A vaccine (group 2) or hepatitis B vaccine (group 3) on the same schedule. Group 3 infants subsequently received hepatitis A vaccine at 8 and 10 months of age. RESULTS: At 15 months of age, 100% of infants in group 1, 93% in group 2, and 92% in group 3 had protective levels of antibody. However, there were significant differences in the geometric mean concentration (GMC) of anti-HAV between groups. Group 1 GMC was 231 mIU/mL, compared with 85 mIU/mL for group 2 and 84 mIU/mL for group 3 (P<.001, group 1 vs group 3). CONCLUSIONS: Passively acquired maternal anti-HAV resulted in a significantly lower final antibody response when infants were administered hepatitis A vaccine at 2, 4, and 6 months of age or at 8 and 10 months of age.     

Control of encapsulation efficiency and initial burst in polymeric microparticle systems

Initial burst is one of the major challenges in protein-encapsulated microparticle systems. Since protein release during the initial stage depends mostly on the diffusional escape of the protein, major approaches to prevent the initial burst have focused on efficient encapsulation of the protein within the microparticles. For this reason, control of encapsulation efficiency and the extent of initial burst are based on common formulation parameters. The present article provides a literature review of the formulation parameters that are known to influence the two properties in the emulsion-solvent evaporation/extraction method. Physical and chemical properties of encapsulating polymers, solvent systems, polymer-drug interactions, and properties of the continuous phase are some of the influential variables. Most parameters affect encapsulation efficiency and initial burst by modifying solidification rate of the dispersed phase. In order to prevent many unfavorable events such as pore formation, drug loss, and drug migration that occur while the dispersed phase is in the semi-solid state, it is important to understand and optimize these variables.     

血液流动在血小板栓子形成中的作用

<正>Microparticles(MPs) are small anucleoid phospholipid vesicles shed from platelets,erythrocytes,leukocytes and endothelial cells.MPs contains a membrane skeletion and are defined by their size and expression on their surface of antigens specific of parental cells.The diameter of MPs are from 0.1 to 1 m.     

Function and Clinical Significance of Platelet-Derived Microparticles

Microparticles released from platelets (PMPs) may play a role in the normal hemostatic response to vascular injury because they demonstrate prothrombinase activity. PMPs were first observed as released vesicles from platelets following adhesion to vessel walls, and flow cytometry is now the most widely used method for studying PMPs. PMPs are thought to play a role in clinical disease because they express phospholipids that function as procoagulants. High shear stress can initiate both platelet aggregation and shedding of procoagulant-containing PMP, suggesting that PMP generation by high shear stress occurs in small diseased arteries and arterioles under various clinical conditions. In addition, the possibility that PMPs evoke cellular responses in their immediate microenvironments has recently been suggested. Despite many interesting findings, the significance of PMPs in various clinical conditions remains controversial. For example, it is not known whether PMPs found in peripheral blood vessels cause thrombosis, or if they are the results of thrombosis. There has been some question about whether the PMPs found in thromboses are consumed locally, meaning that PMPs circulating in the peripheral blood are not functionally important. Currently, the number of clinical disorders associated with elevated PMPs is increasing.     

运用微粒子酶免疫分析法监测肾移植患者雷帕霉素实时治疗窗

目的:实时监测肾移植患者的雷帕霉素血药浓度,研究肾移植患者术后不同时期雷帕霉素治疗窗浓度范围,从而有效指导肾移植患者的合理用药,提高肾移植患者的术后长期存活率及生活质量。方法:采用微粒子酶免疫分析法测定本院64例肾移植患者术后不同时期雷帕霉素血药浓度,同时测定患者肝肾功能,评价疗效。结果:雷帕霉素治疗窗浓度范围术后1个月内为10.0～12.0ng·mL-1,第2～4个月为7.0～10.0ng·mL-1,第5个月以后为4.0～7.0ng·mL-1,上述浓度范围既能达到满意的免疫抑制效果,又能减少雷帕霉素的副作用。结论:雷帕霉素可作为肾植移术后的新型免疫抑制剂,术后治疗窗浓度随时间的延长而改变。微粒子酶免疫分析法可有效地监测患者雷帕霉素的血药浓度,为指导患者的临床用药提供了有价值的参考。