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11.
异种脱细胞角膜基质囊袋移植的生物相容性研究   总被引:2,自引:0,他引:2  
目的探讨脱细胞猪角膜基质移植入兔角膜囊袋后的生物学反应。方法猪角膜通过不同方式去除细胞及免疫源性成分,保留角膜组织基质的弹力纤维及胶原纤维,将其切取为直径为4mm的植片,植入兔角膜囊袋内,在不同时间点观察生物材料在角膜内生物学反应。结果材料植入兔角膜囊袋3个月,生物相容性良好,材料逐渐降解,材料内有胶原和角膜基质细胞长人。结论新型可降解角膜基质材料植入后未见兔角膜有明显的炎症反应,材料的组织相容性好,可作为组织工程角膜的支架材料。  相似文献   
12.
介入用聚氨酯材料的血液相容性研究   总被引:4,自引:2,他引:4  
介入导管优良的血液相容性是确保血管内介入技术安全可靠进行的重要因素,我们对自己合成的四种介入导管用聚氨酯材料的血液相容性进行了评价,包括溶血试验、血小板黏试验、动态凝血时间试验和动态血栓形成实验。结果表明,其中的H50-100和H60-100具有优良的血液相容性,完全可以用作介入导管材料。此外,还讨论了聚氨酯结构与血液相容性的关系。  相似文献   
13.
To identify the advantages of 2-methacryloyloxyethyl phosphorylcholine (MPC) copolymer-coated polysulfone (PSf) hollow fibers for hemodialyzer and hemofilter minimodules with hollow fibers were made and blood compatibility was evaluated in vitro and ex vivo. Three types of hollow fibers, i.e., pure PSf (no additives), PSf alloyed with poly(1-vinyl-2-pyrrolidone) (PVPy), and PSf coated with the MPC copolymer, were processed in wet conditions. Commercially available hollow fibers (APS) were used as a control sample. The PSf hollow fibers have a condensed structure. A porous structure was observed when the PVPy was alloyed before wet processing, and no effect of the innercoated MPC copolymer on the porous structure was observed. One-tenth-sized minimodules of the conventional hemodialyzer were fabricated with 200 fibers each. The solute permeability of the hollow fibers was evaluated using 10% bovine serum in a buffer solution containing cytochrome C, which is a model protein of 2-microglobulin. After circulation for 2.5h, the solute permeability of APS and PVPy-alloyed PSf hollow fibers decreased to 50% compared with their initial values. In contrast, the value for the hollow fibers innercoated with the MPC copolymer maintained its initial level. The inner surface of the dialysis membranes was observed with a transmission electron microscope and a layer of adsorbed protein on the PSf, APS, and PVPy-alloyed PSf hollow fibers was observed, but not on the MPC copolymer-coated fibers. Blood cell adhesion was then evaluated by circulation of whole rabbit blood without any anticoagulant ex vivo. Many adherent cells were observed on the PVPy-alloyed PSf hollow fibers; however, blood cells did not adhere or aggregate on the MPC copolymer-coated hollow fibers. From these results, we concluded that the in-situ coating of MPC copolymer on PSf hollow fibers is effective in preventing blood coagulation and maintaining the solute permeability of the fibers.  相似文献   
14.
Studies on functional compatibility of various Rev proteins derived from all known human and simian immunodeficiency virus subgroups have shown that this essential gene product is not always exchangeable among the viruses. In an attempt to map the region of Rev proteins responsible for the observed nonreciprocal complementation, hybrid genomic Rev expression vectors were constructed by exchanging the first and second exons ofrev genes, and were examined for their abilities to activate reporter clones by transfection. With one exception, the second coding exon ofrev gene determined the functional specificity of Rev proteins.  相似文献   
15.
Perceptual and Motor Space Representation: An Event-Related Potential Study   总被引:2,自引:0,他引:2  
Richard  Ragot 《Psychophysiology》1984,21(2):159-170
The purpose of this experiment was to study the brain potentials generated during spatial tasks related to the “schema corporel” (a mental map of sensory-motor relationships). Seven right-handed subjects performed a choice reaction-time task (Experiment 1), in which the spatial position of a visual stimulus (right or left of a fixation point) was varied independently of the spatial position of the response (right or left hand). The subjects also made self-paced extensions and flexions of the right and left index fingers (Experiment 2). Experiments 1 and 2 were performed with the hands both crossed and uncrossed. Spatio-temporal maps showed that the P300 component elicited by the choice RT situation in Experiment 1 was largest ipsilateral to the hand involved in the response, whether or not the hands were crossed. The later part of the pre-movement potentials during Experiment 2 and the motor potential were significantly larger contralateral to the moving hand under all conditions. Thus this pattern of lateralization can be attributed to the superimposition of a bilateral P300 wave on the asymmetrical motor potential. This suggests that distinct neuronal populations are involved in the generation of these two components. P300 latency and RT reflected the spatial conflict: both were longer when the stimulus and response were on opposite sides than when they were on the same side, even when the hands were crossed. However, the average P300 latency was not increased when the hands were crossed, whereas the average RT was substantially increased. Since the additional time required for programming the movement in the crossed hand situation had no effect on P300 generation, we infer that the P300 does not index this motor programming. However, P300 does reflect the stimulus-response spatial matching, since its latency was delayed by spatial conflict.  相似文献   
16.
mPEG表面修饰的PLGA嵌段共聚物的血液相容性评价   总被引:3,自引:0,他引:3  
本实验室设计合成了三种不同LA/GA比例的mPEG修饰PLGA(PELGA,含15%mPEG),为了评价它们的血液相容性,我们以硅化玻璃试管为阴性对照,未硅化的试管为阳性对照,参照国际标准(ISO10993)和《中华人民共和国国家标准GB/T16886医疗器械生物学评价》方法进行了体外评价实验。试验包括溶血率实验,血小板黏附实验,动态凝血时间实验,凝血时间实验,血浆复钙时间实验和凝血酶原时间实验等综合评价指标。结果表明,合成材料具有优良的血液相容性,材料制成的纳米粒有望应用于静脉注射。  相似文献   
17.
Using 12 healthy male subjects, the dynamic motor ability of individual fingers was investigated under four different finger tapping conditions. These were: maximum speed tapping with one finger (single-finger tapping), alternate movement of two fingers (double-finger tapping), double-finger tapping in an unsupported condition, and submaximum constant speed tapping with one finger in a passive manner. Key-contact forces for all fingers and the movement velocity of the tapping finger were monitored. With the exception of the unsupported condition, non-tapping fingers were maintained in contact with designated keys during the tapping tasks. It was found that the index finger attained the fastest cadence and greatest movement velocity, followed by the middle, little and ring fingers, respectively. Subjective assessment of rank order of "difficulty" of tapping by the subjects was highly correlated with tapping cadence. Thus dynamic motor function, as indicated by rapid, repetitive movement, differs among the individual fingers. Parallel changes were observed in the key-contact force of the neighboring non-tapping fingers during tapping. The range of the non-tapping finger forces was largest during tapping by the ring finger. A similar trend was found for passive tapping, during which the magnitude of key-contact force was less than one-third of that observed during active tapping. The lower cadence achieved by the ring finger may be attributed more to a lack of independence at the level of voluntary neuromuscular control, than to innate mechanical interaction with the other fingers. Tapping cadence of each finger was lower for the double-finger mode than for the single-finger mode. The magnitude of the observed decrease in cadence during double-finger tapping was, on the other hand, strongly dependent on finger-combination. The decrease was smallest for the index-middle finger-combination, and greatest for the ring-little finger-combination. Compatibilities with other fingers can play an essential role in the dynamic motor function of individual fingers. During the unsupported task, in which interactions were diminished by allowing all fingers to move freely, tapping cadence increased markedly. Therefore, the lower cadences observed in specific finger-combinations may be partly attributed to anatomical and neural interdigit interactions.  相似文献   
18.
《Human immunology》2022,83(3):219-224
To date, traditional pre-transplant risk factors have failed to provide accurate risk stratification in transplantation. As a result, the practice of precision medicine remains elusive, resulting in a one-size-fits-all therapeutic approach for most patients. However, recent advancements in the understanding of HLA molecules at the molecular level have revitalized interest in HLA mismatch assessment. This review discusses HLA molecular mismatch as a potential prognostic and predictive biomarker available at the time of transplantation and answers some of the common questions and critiques of this approach. We highlight the retrospective data that supports single molecule risk categorization and explore the next steps required to evaluate its potential in clinical practice.  相似文献   
19.
石膏解肌之说由来已久,但限于矿物药的溶出及研究手段有限等现实问题,其临床推广及应用不足,深入探讨亦不足。该文通过梳理解肌法的脉络,总结出解肌法所针对的病机为“津液不足,兼表不和”,而石膏解肌的核心内涵为“清火存液,兼透表邪”;通过梳理解肌法的古今运用,结合配位化学的现代研究,从配伍角度入手,主以《伤寒论》和《金匮要略》中的经方为例,拓展了石膏解肌之内涵,总结出石膏的解肌作用不仅可以治疗外感后的肌肉不适症状,还可能影响脏腑功能,进而治疗内伤杂病,并由此提出“石膏配伍解肌法”,认为石膏与麻黄、葛根、防己、知母、人参、芍药、竹茹、生地黄、麦冬和葳蕤等药物配伍后,通过调整透散和清热的力度来更好地发挥解肌作用。该文附临床验案一则予以阐发,以期为石膏的临床运用提供参考,为其配伍使用的药物机制研究提供方向。  相似文献   
20.
目的:基于数据挖掘技术分析文献中针刺治疗视网膜色素变性穴位的组方规律。方法:检索国家知识基础设施数据库(CNKI)、中国学术期刊数据库(CSPD)、中文科技期刊数据库(CCD)文献中治疗视网膜色素变性所使用的穴位处方,使用中医传承计算平台(V3.1)进行数据挖掘,分析针刺治疗视网膜色素变性的取经、选穴和配伍规律。结果:共纳入文献47篇,应用频次前5位的腧穴为球后、睛明、太阳、足三里、合谷;奇穴选用频次最高,经脉选用频次前3位依次为足太阳膀胱经、足少阳胆经、足阳明胃经;取穴部位以头颈部选取最多;其次为下肢部和上肢部。结论:针刺治疗视网膜色素变性的核心经脉为足太阳膀胱经、足少阳胆经及足阳明胃经,核心组穴为球后、睛明及太阳,配以足三里、合谷、光明、三阴交等穴,其取穴规律以局部取穴以及邻近取穴直达病所为主,远端取穴以足三里、合谷等辅以调理脏腑经络。  相似文献   
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