神经生长因子几丁质管修复兔面神经缺损

目的：评价神经生长因子(nerve growth factor，NGF)几丁质管在修复兔面神经缺损中的作用。方法：在16只新西兰兔的两侧面神经上颊支上分别造成8mm缺损，左侧用管腔内注入NGF的几丁质管修复，右侧用自体神经移植修复作对照。术后8周和16周分别取8只动物进行电生理和组织学检查及计算机图像分析。结果：术后8周，实验组的再生神经已通过近远中吻合口，神经纤维密集成束；术后16周，再生神经纤维的数量增加，神经纤维束增粗，形态接近于正常神经。电生理检测和图像分析显示实验组和对照组的神经传导速度和有髓神经轴突总截面积均无显著差异(P＞0．05)。结论：NGF几丁质管可为免面神经缺损提供良好的修复环境。     

Histological and clinical responses of articular cartilage to low-level laser therapy: Experimental study

This study was carried out to evaluate the effects of low-level laser irradiation on experimental lesions of articular cartilage. A standard lesion was practised on the femoral trochlea of both hindlimbs of 20 clinically normal Californian rabbits. These animals were divided into two groups of 10 individuals each, depending on the laser equipment used for treatment. Onc group was treated with He-Ne laser (8 J cm^-2, 632.8 nm wavelength) and the other with infra-red (IR) laser (8 J cm^-2, 904 nm wavelength). In both groups, five points of irradiation to the right limb alone were irradiated per session for a total of 13 sessions, applied with an interval of 24 h between sessions. These points were the following: left and right femoral epicondyles, left and right tibial condyles and the centre of articulation. The distance between these points was approximately 1 cm. The untreated left limb was left as a control. During treatment, extension angle and periarticular thickness were considered. At the end of the treatment, samples were collected for histopathologi-cal study and stained with: Haematoxylin-Eosin, PAS and Done. The results show a statistically higher anti-inflammatory capacity of the IR laser (p < 0.0001). The functional recovery was statistically similar for both treatments (p < 0.176). Histological study showed, at the end of the treatment, hyaline cartilage in the IR group, fibrocartilage in the He-Ne group and granulation tissue in the control limbs. Clinical and histological results indicated that this laser treatment had a clear anti-inflammatory effect that provided a fast recuperation and regeneration of the articular cartilage.     

骺板软骨细胞复合三维支架体外构建组织工程软骨的研究

目的探讨将骺板软骨细胞复合三维支架经体外培养,构建组织工程软骨的效果及其生物学特点. 方法将3周龄幼兔第1代骺板软骨细胞与液态的生物凝胶混合,接种于聚磷酸钙纤维/L-聚乳酸(CPPF/PLLA)三维支架材料,构建组织工程软骨组织块,连续培养4周.行大体、倒置显微镜及组织学、Ⅰ型和Ⅱ型胶原免疫组织化学光镜观察,定量检测硫酸糖胺多糖(GAG)含量. 结果构建的组织工程软骨块在培养过程中能保持其初始外形,种子细胞呈稳定的三维均相分布,外观逐渐呈乳白色、半透明,硬度亦不断增加.培养1周有软骨细胞陷窝形成,2周后形成富含Ⅱ型胶原和蛋白聚糖、具有典型软骨组织结构的工程化软骨,且Ⅰ型胶原逐渐转为阴性.4周时构建软骨的组织结构与天然骺板软骨相类似,硫酸GAG含量平均为天然骺板软骨的34%以上. 结论骺板软骨细胞复合三维支架体外培养可生成典型软骨,且可形成类似天然骺板软骨的组织结构,能满足修复骺板缺损的基本要求.体外培养1～2周可能是植入体内修复骺板缺损的较佳时机.     

硒螺旋藻对大鼠肝叶切除术后肝细胞再生和抗氧化能力的影响

目的研究硒螺旋藻（Se—SP）对大鼠肝叶切除术后肝细胞再生和抗氧化能力的影响，以印证其生物利用价值。方法用Wistar大鼠复制67％肝叶切除动物模型，设Se—SP高剂量（H）和低剂量（L）治疗组，术前以Se—SP灌胃7d；另设生理盐水（C）及假手术对照组（S）。于手术前及其后24h取鼠肝细胞，检测硒（Se）、丙二醛（MDA）含量及谷胱甘肽过氧化物酶（GPx）和超氧化物歧化酶（SOD）活性；利用免疫组化方法测定肝细胞增生核抗原（PCNA）表达指数，慧星实验检测过氧化氢诱导的肝细胞DNA损伤。结果与C，S组相比，H组、L组肝细胞中MDA水平明显降低（P〈0．05），而Se，GPx和SOD明显升高（P〈0．05）；肝细胞PCNA指数明显升高（P〈0．05），过氧化氢诱导的DNA损伤程度较轻。结论Se—SP对肝切除鼠肝细胞具有一定的抗氧化和促再生作用。     

再生医学技术在烧伤传统治疗无效病人中的应用(附38例报告)

目的：总结重度烧伤传统疗法无效改为再生医学(MEBT/MEB0)技术治疗变化规律和临床验．方法：将我科l995年5月至2002年5月收治的院外采用传统疗法无效改用MEBT/MEBO技术治疗的38例重度烧伤病人临床资料进行回顾性总结，病人一旦入院创面均改用MEBT/MEBO治疗，初始予以彻底清创，规范用药、规范操作，规范认识；全身实行系统综合治疗措施．以临床观察和病人感觉评价治疗效果。结果：本组38例全部治愈，末植皮自行愈合者21例．占55.26％．深Ⅲ度创面自愿要求植皮者17例，占44.74％。经随访多数无增生性瘢痕，部分愈后有局限性瘢癌，质软无残废。结论：重度烧伤经传统疗法久治不愈或疗效欠佳病人．病情复杂，并发症较多治疗难度也较大，再生医学可有效改善以上缺陷和病症．是重度烧伤病人传统治疗无效时的理想疗法。     

毛囊细胞移植诱导裸鼠毛囊样结构形成的研究

目的:观察毛囊细胞移植诱导裸鼠毛发再生和毛囊重建情况.方法:采用细胞培养技术和裸鼠移植技术,将培养的毛囊毛乳头细胞、真皮鞘细胞和头皮真皮成纤维细胞按比例与毛囊上皮细胞混合,移植到裸鼠皮下,观察毛囊形成情况.结果:在毛囊毛乳头细胞与毛囊上皮细胞混合后移植到裸鼠皮下后可见毛囊样结构形成,而毛囊真皮鞘细胞和头皮成纤维细胞与毛囊上皮细胞混合则不能诱导裸鼠毛囊样结构形成.结论:低传代培养的毛乳头细胞与毛囊上皮细胞混合后在体内可诱导毛囊样结构形成.     

Effects of diflubenzuron on limb regeneration and molting in the fiddler crab, Uca pugilator

Fiddler crabs, Uca pugilator, were exposed to the insect growth regulator diflubenzuron (Dimilin^®) at 0.5, 5, and 50 μg/l after multiple autotomy of one chela and five walking legs. Regeneration of the first walking leg was monitored, and time to ecdysis, mortality, and morphology of the regenerated limbs observed. Continuous exposure to the chemical produced a dose-dependent retardation of regeneration. Animals molting in the higher concentrations exhibited significant mortality at ecdysis. Exposure to the pesticide for a single week produced similar but less severe effects. However, if crabs molted while in the pesticide, significant mortality was observed. The presence of sediment in the container with the crab moderated the effects of the pesticide, but did not eliminate them.

The regenerated limbs of the crabs that survived ecdysis were found to have lesions in the form of black areas in which the cuticle was improperly developed. These lesions were seen in crabs that had been in the pesticide for only one week (week 2 or week 3) as well as those that had had continuous exposure. They were also seen in crabs that regenerated in Dimilin with sediment. In addition, the number of setae on limbs was reduced compared to the number on limbs that had regenerated in clean sea water.     

The regulative potential of the limb region in 11.5-day rat embryos following the amputation of the fore-limb bud

Summary The regulative potential of the fore-limb region following the removal of the limb bud was investigated in 11.5-day rat embryos. Fore-limb buds were amputated from a total of 54 embryos. Five embryos were immediately examined via scanning electron microscopy (SEM) to assess the quality of the operation and the reproducibility of the technique. In all cases, the forelimb bud and adjacent tissues extending down to the celomic cavity at the same level were completely removed. The remaining 49 operated embryos were cultured in vitro and examined at different time intervals. Gross inspection of embryos which had been cultured for 24 h, revealed that 24 out of 37 had developed a pair of limb bud-like protrusions at the operation site. Twelve formed only a single protrusion, while nothing was found in the remaining embryo. These protrusions were examined in greater detail under SEM and light microscopy. SEM observations showed that these protrusions were covered with an intact layer of ectoderm. In embryos with a pair of protrusions, these outgrowths developed opposite somites 7 to 13. The failure of either one of these two outgrowths to form, produced our second type of experimental embryo, those which had just a single protrusion. Histological examination revealed that an apical ectodermal ridge (AER) was discernible on the protrusions of 36% of the embryos. Finally, we have established how these protrusions were constructed from SEM observations of operated embryos cultured for 6 h and 10 h.     

氟尿嘧啶引起大鼠气管损伤修复过程中干细胞的定位

目的 气管干细胞的原位观察。方法 使用5-氟尿嘧啶(5-FU)造成大鼠离体气管环的严重损伤，采用光镜、PCNA免疫组织化学，以及Hoechst33342染色观察气管黏膜的修复过程。结果 5-Fu作用12h后，气管上皮脱落，可见少量间隔分布的类似裸核的细胞呈钉状位于基底膜上，PCNA染色阴性(Go期细胞)，其中少数细胞Hoechst33342染色阴性。去除5-FU6h后，气管黏膜由扁平上皮覆盖；48h后，气管环恢复假复层纤毛柱状上皮。结论 5-Fu能杀死处于细胞周期的气管上皮细胞，对Go期细胞作用很小，残留于基底膜上的裸核样的Go期细胞中含有干细胞，其Hoechst33342染色阴性，并具有排出荧光染料的能力，正是这些细胞的增殖分化，修复了损伤的气管环。     

Gradual and reversible central vestibular reorganization in frog after selective labyrinthine nerve branch lesions

Postlesional reorganization of vestibular afferent and commissural inputs onto second-order vestibular neurons was studied in the isolated brain after unilateral section of the N.VIII, of the ramus anterior (RA) of N.VIII, of the utricular (UT) or of the anterior vertical and horizontal canal nerves in combination. RA nerve section eliminated the inputs from utricular, anterior vertical and horizontal canal organs. In the first set of experiments we recorded field potentials on the operated side of the vestibular nuclei 2 months after RA nerve section. These responses were evoked by electrical stimulation of the RA nerve or of the posterior vertical canal nerve on the operated or on the intact side. The amplitudes of afferent field potentials evoked by stimulation of the spared posterior vertical canal nerve were increased. The amplitudes of afferent field potentials evoked by stimulation of the axotomized RA nerve remained unaltered. After N.VIII section the commissural, but not the afferent, field potentials increased significantly on the operated side following stimulation of N.VIII on the intact and on the operated side, respectively. After UT nerve section no change in commissural but an increase in the amplitude of afferent field potentials from each of the three intact canal nerves was observed on the operated side. In the context of earlier results these findings imply that second-order vestibular neurons, disfacilitated due to afferent nerve section, became receptive to additional, excitatory synaptic inputs, preferentially from intact vestibular nerve afferent fibers. The reduced excitation via afferent nerve inputs was thereby replaced by other afferent nerve inputs from spatially inadequate vestibular end-organs. The synaptic terminals of inactivated afferent nerve fibers were maintained and not repressed. The process of central reorganization after vestibular nerve lesion was activity related, the expansion of signals restricted to inputs from intact fibers, its extent graded and its onset delayed with respect to the onset of corresponding spinal changes and to the onset of postural recovery after the same type of nerve lesion. After the section of RA nerve or of an individual nerve branch the labyrinthine end-organs remained intact and were not removed as after unilateral labyrinthectomy (UL). Peripheral reinnervation of the end-organs was thus excluded after UL, but expected after one of the former types of lesion. Functional reinnervation of the utricular macula was mirrored behaviorally by the reappearance of severe postural deficits following a second RA nerve section. These lesion-induced postural deficits began to reappear if the repeated RA nerve section was delayed with respect to the first by about 3 months. We therefore studied postlesional reorganization in the brainstem 3 months after the first RA nerve section. Reinnervation of the utricular macula was accompanied by a rapid decline of the increased amplitudes of afferent and commissural vestibular field potentials towards control values, suggesting the reversibility of the lesion-induced central reorganization. Electronic Publication