复合神经营养因子的神经导管研究进展

目前周围神经的组织工程研究热点之一就是研制具有生物活性的神经导管,主要方法是神经导管与雪旺细胞或者神经营养因子相结合来促进周围神经的再生。就复合神经营养因子的神经导管的相关研究进展作一综述。     

自体移植脾组织VEGF、KDR表达与血管再生的实验研究

目的 研究自体移植脾组织血管再生及VEGF、KDR表达规律，阐明VEGF、KDR对移植脾组织血管再生的调控作用，为脾脏外科临床及实验研究提供理论依据。方法 健康Wistar大鼠70只，体重100—120g，随机分为7组，每组10只中又设脾切除自体脾移植组5只，假手术组5只，分别于术后7，14，30，60，90，120，180d进行：(1)自体移植脾组织病理学检测；(2)大鼠行主动脉插管灌注墨汁，光镜观测再生血管并采用图像分析测定其密度；(3)免疫组化抗VEGF、KDR抗体染色，图像分析定量，阐明其表达规律及与血管再生的关系。结果 (1)自体脾组织移植术后7d即有血管从大网膜向脾组织内伸展，移植脾组织内血管密度逐渐增大，至术后180d血管再生接近正常；(2)自体脾组织移植术后7d、14d，VEGF、KDR阳性染色细胞密度迅速升高，术后60d达高峰，以后逐渐降低，至术后180d VEGF、KDR阳性染色细胞密度趋向正常。结论 自体脾组织大网膜内移植术是简便有效的脾移植方法；移植脾组织新生血管由大网膜再生而来；术后移植脾组织内VEGF、KDR表达量升高，促进血管形成，血管再生完成后恢复正常水平。     

应用和推广烧伤皮肤再生医疗技术的体会(二)

目的：通过临床实践总结、分析、认识干细胞与再生医学理论在烧伤创疡中的作用与效果；方法：应用MEBT／MEBO观察烧伤创疡创面的再生修复变化。结果：MEBT／MEBO治疗77种创疡疾病冶愈率达92％以上，有效率达100％。结论：MEBT／MEN)治疗慢性体表性溃疡及皮肤病性皮肤损伤、感染性溃疡效果满意。     

微囊化人头皮毛乳头细胞诱导小鼠耳毛囊再生的研究

目的 观察人头皮毛乳头细胞海藻酸钠-多聚赖氨酸-海藻酸钠（alginate-polylysine-alginate，APA）微囊是否具备诱导小鼠耳部毛囊再生的功能；寻找理想的微囊直径。方法 以APA微囊包裹体外分离培养的人头皮毛乳头细胞；将毛乳头细胞微囊移植至小鼠耳部皮下，6周后局部取材行组织学检查；共聚焦显微镜下观察葡聚糖-荧光素在APA微囊中的扩散速度和扩散方式，并对比相同时间、不同直径的APA微囊中葡聚糖-荧光素的强度，综合分析确定最佳的微囊直径。结果 组织学检查显示：移植部位皮下有密集的同心圆状毛囊结构形成，其数量、大小、分化程度等与对照组明显不同。荧光素以同心圆状、逐层渗透的方式向APA微囊中扩散；相同时间内荧光强度比较：小囊组〉中囊组〉大囊组。结论 微囊化毛乳头细胞具备诱导毛囊再生的生理功能；微囊理想的直径是400μm。     

大鼠门静脉分支结扎后肝再生的实验研究

目的 采用手术方法结扎门静脉分支，观察对侧肝脏的再生状态。方法 健康Wistar雄性大鼠60只，随机均分成结扎组和假结扎组，在乙醚麻醉下行门静脉左支结扎和假结扎手术，分别在术后第1、2、3、7及14d用乙醚麻醉动物，心脏采血检测血清ALT值，取出肝脏后称重量；在光镜下观察肝组织的病理变化，并计数肝细胞核分裂指数；采用免疫组化的方法计数增殖细胞核抗原（PCNA）指数；在电镜下观察肝细胞超微结构变化。结果 ①血清ALT值结扎组与假结扎组比较在术后第1d升高（P〈0．01），但在第2d开始恢复正常；②肝脏重量两组间差异无统计学意义（P〉0．05）；③肝细胞核分裂指数结扎组与假结扎组比较，术后第1～3d明显升高，第2d达高峰，第3d有所下降，但仍高于假结扎组（P〈0．01），以后逐渐恢复正常；④PCNA阳性细胞计数结扎组与假结扎组比较，术后第1～3d明显增多，第2d达高峰，第3d有所减少，但仍高于假结扎组（P〈0．01），以后逐渐恢复正常。结论 ①大鼠门静脉左支结扎后，引起未结扎侧肝细胞的活跃再生，再生后的肝脏可恢复原来的重量；②大鼠75％肝叶的门静脉分支结扎不影响肝功能，是安全可行的；③大鼠门静脉分支结扎可以作为研究肝脏再生动物模型的方法。     

角膜损伤后神经再生的实验研究

应用神经组织化学技术观察了兔角膜NA能神经及AchE阳性神经在角膜损伤后的再生,证实术后1月,两种神经均有再生轴突进入植片;术后3月可见交界区和植床内神经密度明显增加;同时,对术后两种神经再生的功能意义进行了讨论。     

SCHWANN CELLS AND THE REGROWTH OF AXONS IN THE MAMMALIAN CNS: A REVIEW OF TRANSPLANTATION STUDIES IN THE RAT VISUAL SYSTEM

1. We have used peripheral nerve transplants or cultured Schwann cells grafted in association with different types of polymer to study axonal regrowth in the rat visual system. In some instances the glia were co-grafted with fetal tectal tissue. 2. The studies have two main aims: (i) to determine whether retinal axons can be induced to regrow at a site distant from their cell soma, that is, after damage to the brachial region of the optic tract; (ii) to determine whether retinal axons exposed to Schwann cells retain the ability to recognize their appropriate target neurons in CNS tissue. 3. In brachial lesion studies, Schwann cells were placed in the lesion site in association with nitrocellulose papers, within polycarbonate tubes in the presence or absence of a supporting extracellular matrix (ECM), or within polymer hydrogel scaffolds. Autologous sciatic nerve grafts were also used. Immuno-histochemical studies revealed the presence of regenerating axons within all polymer bridges. Regrowth of retinal axons was also seen, however, growth was not extensive and was limited to the proximal 1–1.5 mm of the implants. 4. In target innervation experiments, two surgical paradigms were developed. In one experiment, a segment of sciatic nerve was autografted onto the transected optic nerve in adult rats and the distal end of each graft was placed adjacent to fetal tectal (target) tissue implanted into the frontal cortex. To date, we have not been able to demonstrate selective recognition of target regions within tectal transplants by retinal axons exiting the sciatic nerve implants. 5. In the second experiment, Schwann cells were mixed with fetal tectal cells and co-grafted to the midbrain of newborn host rats. Schwann cells altered the characteristic pattern of host retinal growth into tectal grafts; in some cases axons were induced to grow away from appropriate target areas by nearby co-grafted Schwann cells. 6. In summary, Schwann cell/polymer scaffolds may provide a useful way of promoting the regrowth of damaged axons in the CNS, however: (i) in adults, at least, their effectiveness is reduced if they are located at a distance from the cell bodies giving rise to regenerating axons; (ii) in some circumstances exposure to a peripheral glial environment may affect the capacity of regenerating axons to recognize appropriate target cells in the CNS neuropil.     

Application of an immunosensor for the detection of the β-lactam antibiotic, cephalexin

Public concern surrounding antibiotic contamination in food and food products has made it imperative to develop analytical methods for their detection. Polyclonal antibodies were used in the development of a surface plasmon resonance (SPR)-based inhibition immunoassay for cephalexin. A conjugate consisting of cephalexin-bovine serum albumin (BSA) was immobilized on the dextran gel surface of the sensor chip. Binding/regeneration studies of antibody to immobilized cephalexin were studied and dissociation of the antibody from the immobilized cephalexin was easily achieved with 10 mmol l^-1 NaOH. Forty surface regeneration cycles were carried out and found to be reproducible with only a 7.4% decrease in binding over this number of regenerations. Model inhibition immunoassays for cephalexin were developed in PBS and spiked milk samples with detection ranges of 4.88 to 2,500 ng ml^-1 and 244 to 3,906 pg ml^-1, respectively.     

Long-term result of guided nerve regeneration with an inert microporous polytetrafluoroethylene conduit

Thedevelopmentinmicrosurgicaltechniqueshasgreatlyimprovednervefunctionalrecovery .However ,owingtotheinabilitytocoaptateandsuturethousandsofnervefiberstotheirfunctionallysimilarnervefibersandinaccuratesutureofthenervestumps ,regeneratednervefiberspartiallylosethechancetoselectivelyregrowintotheirtargetendoneurialtubes,1 4whichresultsinaninevitablemismatchofmotorandsensorynervefibers .Thus,thecontact guidance basedmicrosurgicalnerverepairhasfailedtoachieveconsistentsatisfactoryfunctionalrecover…