TIA继发脑梗死的TCD、EEG与CT、MRI的动态研究初探

目的探讨TIA继发脑梗死的TCD动态变化规律以及与病情预后、神经电生理、神经影像之间的关系。方法对TIA继发脑梗死患者在入院即刻、脑梗死后第1、3、7、14天进行床边TCD动态观察,并与EEG、头颅CT、MRI和NIHSS评分进行对比研究及相关分析。结果入院即刻TCD异常率高于头颅CT、MRI和EEG,并且异常程度与NIHSS评分成正比关系,能更早预测患者病情及预后。结论对TIA继发脑梗死的患者,TCD具有较高的早期诊断价值,入院即刻TCD的异常程度与脑梗死后病情严重程度及早期预后有关,有助于判断病情及预后。     

高血压脑出血术后动态经颅多普勒超声与颅内压监护仪监测的临床意义

目的 探讨高血压脑出血手术方式以及术后如何控制血压.方法 对与96例高血压脑出血患者分别行开颅血肿清除术和血肿腔钻孔引流术,同时对每例患者行颅内压和平均动脉压连续监测7 d,同时监测术后1、3、7、14 d行双侧大脑中动脉平均血流速度和搏动指数值.结果 开颅术对于血肿量>50 ml的患者远期生存质量(6月后ADL分级)与血肿腔钻孔引流术比较有显著差异;另外术后1 d、3 d、7 d、14 d的TCD参数结果分析,开颅术对于缓解颅内压力、改善脑血流优于钻孔引流组.对所有患者术后ICP、MAP监测能有效控制血压防止再出血.结论 对于血肿量>50 ml患者应选择开颅手术.对所有高血压脑出血患者术后应常规进行ICP、MAP监测.     

风湿性心脏病伴发脑栓塞患者脑血流动力学初探

目的：研究风湿性心脏病伴发血栓脱落致脑栓塞(stroke caused by thrombosis of rheumatic heart disease,RHD)患者的血流动力学特征。方法：用经颅多普勒超声(transcranial Doppler,TCD)连续观查30例确诊的风湿性心脏病伴发血栓脱落致脑栓塞患者,另选同期在我院体检中心体检的正常患者60例进行对照。结果：RHD患者主要表现为椎基底动脉收缩期血流缓慢、脉动指数降低、Vp和Vm间的差距变小、波峰圆钝、多数患者出现频窗充填。除Vd值以外,两组病人左右椎动脉和基底动脉的Vp、Vm、PI值间均存在显著性差异(P<0.05)。结论：RHD患者的血流动力学表现具有相对的特异性,TCD可作为其临床初步筛查和辅助诊断手段之一。     

西比灵治疗椎基底动脉供血不足的研究

目的 :研究椎基底动脉供血不足 (VBI)所致的眩晕、共济失调、耳鸣、无力等 ,用西比灵治疗前后血液流变性、经颅多普勒 (TCD)及甲襞微循环的变化和症状改善情况。方法 :76例VBI患者随机分为二组 ,以维脑路通作对照 ,常规用药 ,治疗前后检查上述指标。结果 :西比灵治疗后血浆粘度、红细胞压积和红细胞聚集指数显著下降 ,TCD检查血流速度加快 ,频谱频窗异常状况有明显好转 ,甲襞微循环流速流态、管袢清晰度及临床症状显著改善 (P <0 .0 5～ 0 .0 1 )。结论 :西比灵能扩张血管 ,降低血粘度 ,改善微循环 ,治疗VBI。     

Synthesis and Characterization of a Temperature-Responsive Biocompatible Poly(N-vinylcaprolactam) Cryogel: a Step Towards Designing a Novel Cell Scaffold

A poly(N-vinylcaprolactam) (PVCl) cryogel and poly(N-vinylcaprolactam)-co-gelatin interpenetrating cryogel network were synthesized and characterized with respect to physical and biological properties. The PVCl cryogel was synthesized in 5% dimethyl sulfoxide (DMSO) containing aqueous medium and PVCl-co-gelatin interpenetrating cryogel network was synthesized in water as solvent. Both these cryogel networks have good physical morphology as confirmed by scanning electron microscopy. The porosity of these cryogels were characterized by various methods like, adsorption of water and cyclohexane and confirmed by analysis on mercury porosimeter and nitrogen adsorption studies. The porosity of PVCl and PVCl-co-gelatin cryogels was 96% and 98%, respectively, and the permeability of the two types of cryogels was 1.01 × 10^?12 m⁴/Ns and 1.66 × 10^?12 m⁴/Ns, respectively. The effective diffusion coefficients (D _eff) of bovine serum albumin (BSA) in PVCl cryogel and PVCl-co-gelatin cryogel were 3.5 × 10^?7 cm²/s and 3.4 × 10^?7 cm²/s, respectively. These materials were further characterized to demonstrate its interaction with biological system. The blood compatibility studies showed minimal hemolysis (4–6%) caused by these materials and a very low adsorption of BSA (0.001–0.002 mg/g dry scaffold). However, the fetal bovine serum (FBS) adsorption studies demonstrate the protein binding at 37°C. Furthermore, cytotoxicity test and the fibroblast cell adhesion studies showed the potential of these PVCl-based cryogels for suitable biomaterial applications.     

Exploiting the current paradigm of blood–material interactions for the rational design of blood-compatible materials

The paradigm of tissue-material interactions, which holds that protein adsorption is the first event following contact and determines the later interactions of cells, is invoked to propose a design strategy for biocompatibility. Control of protein interactions is the key element, and it is suggested that nonspecific protein adsorption must be prevented while the adsorption of specific proteins that are expected to result in appropriate bioactivity must be promoted. Modification with polyethylene oxide has been investigated extensively as a means of preventing nonspecific adsorption. Examples of proteins that could be targeted for specific adsorption are antithrombin III to prevent coagulation and albumin to minimize platelet adhesion. Two examples of surfaces designed for specific adsorption from the author's laboratory are discussed: the incorporation of thrombin binding peptides to give a thrombin scavenging surface, and the incorporation of lysine to give a plasminogen specific surface with the potential to dissolve clots.     

Gas transfer and blood compatibility of asymmetric polyimide hollow fiber

We have fabricated an asymmetric polyimide hollow fiber for use as a membrane oxygenator. A dry/wet phase inversion process has been applied to a spinning process to prepare the hollow fiber. The fiber structure consisted of a complete defect-free skin layer and a porous substructure characterized by the presence of an open-cell structure and macrovoids. The outer diameter was 480 μm with a wall thickness of 50 μm. Transfer rates of O2 and CO2 in the asymmetric polyimide fiber were 2.3 × 10^-5 and 1.1 × 10^-4 (cm³(STP)/(cm²s cmHg)), respectively, which were four times higher than those measured in the polydimethylsiloxane (PDMS) fiber of the presentlyavailable membrane oxygenator. The (QO₂ /Q_N2)selectivity of the polyimide fiber was 4.9, indicating that the surface skin layer is essentially defect-free. The blood compatibility of the polyimide hollow fiber has been evaluated in vitro and in vivo. The polyimide had an excellent blood compatibility when compared with PDMS.     

Selective binding of albumin on stearyl poly(ethylene oxide) coupling polymer-modified poly(ether urethane) surfaces

A tri-block-coupling polymer of stearyl poly(ethylene oxide)-4,4′-methylene diphenyl diisocyanate-stearyl poly(ethylene oxide)(MSPEO), was used as a surface modifying additive (SMA) and the MSPEO-modified poly(ether urethane) (PEU) surfaces were prepared by the process of dipcoating. The surface analysis by XPS revealed the surface enrichment of poly(ethylene oxide) (PEO). On the coating-modified surfaces, the bovine serum albumin (BSA) adsorption, respectively, from the low and high BSA bulk concentration solutions was correspondingly characterized by the methods of radioactive ¹²⁵I-probe and ATR-FTIR. The bovine serum fibrinogen (Fg)-adsorption from the Fg bulk solution and the BSA-Fg competing adsorption from the BSA-Fg binary solutions were also characterized by radioactive ¹²⁵I-probe. The reversible BSA-selective in situ adsorption on MSPEO-modified PEU surfaces were achieved, and the performance of blood compatibility on the coating-modified surfaces was also confirmed, respectively, by plasma recalcification time (PRT) and prothrombin time (PT) tests.     

Chimerism and tolerance: From freemartin cattle and neonatal mice to humans

Bone marrow transplantation (BMT) results in hematopoietic chimeras that demonstrate donor specific tolerance to tissue and cellular grafts. The clinical application of chimerism to induce tolerance is limited by the morbidity associated with human BMT: failure of engraftment, graft-versushost disease (GVHD), and toxic host conditioning.

BMT in an immunologically mature host has until recently been believed to require complete ablation of the host's immune system to allow donor engraftment. Lethal conditioning is associated with significant morbidity and mortality. Stable multilineage mixed allogeneic chimerism has more recently been achieved in mice using partial myeloablation prior to BMT. Chimeras prepared in this fashion exhibit donor specific tolerance in vitro and in vivo similar to lethally-conditioned recipients. A second factor that has limited the widespread application of BMT to nonmalignant disease, including attempts to induce tolerance, is GVHD. Although T-cell depletion of donor marrow reduces the incidence of GVHD, engraftment is often jeopardized. Although highly purified stem cells (SC) engraft at relatively low doses in syngeneic recipients, they do not durably engraft in MHC-disparate recipients. It has recently become clear that a second cell (facilitating cell) that enhances bone marrow engraftment and minimizes the occurrence of GVHD is required for SC to engraft in MHC-disparate recipients. Methods to optimize engraftment yet minimize GVHD may provide an approach to apply BMT clinically. With decreased morbidity through incomplete recipient conditioning and the ability to engineer a bone marrow graft to contain only the desired cells to optimize engraftment, BMT may provide a reasonable strategy to treat nonmalignant diseases including enzyme deficiencies, hemoglobinopathies, autoimmune diseases, and species-specific viral infections such as HIV. BMT-induced donor specific tolerance may benefit recipients of solid organ transplants by eliminating the need for nonspecific immunosuppression and by preventing chronic rejection. This review will focus on approaches to enable BMT yet minimize recipient morbidity and mortality.     

氯吡格雷治疗微栓子阳性脑梗死患者二年随访报告

目的:探讨经颅多普勒(TCD)检测氯吡格雷治疗脑梗死患者对微栓子(MES)的干预作用。方法:将220例MES阳性脑梗死患者分为普通组(对照组)、氯吡格雷治疗组(治疗组)来研究氯吡格雷治疗对MES的干预作用并随访二年后的脑血管事件发生情况。结果:治疗组出院后半年内、半年至1年内、1年至2年内MES阳性率低于对照组(P<0.01),缺血性脑血管事件发生率少于对照组(P<0.05)。结论:氯吡格雷可稳定动脉粥样硬化斑块,减少MES形成,有效预防缺血性脑血管事件的发生。