Spinal cord injury is one of the important field of neuroscience, and neural tract tracing techniques are important research tools. The neural fiber types in the spinal cord are complex, and there are some difference in structures between human beings and animals. This article reviewed different types of neural fibers closely related with spinal cord injury and regeneration, the difference between human beings and animals, and the application of neural tract tracing techniques in the study of spinal cord injury and regeneration.

Objective To study the impact of surgical treatment on the hearing of patients with middle ear cholesteatoma and labyrinthine fistula.Methods The clinical data of 35 patients (35 ears) with middle ear cholesteatoma and labyrinthine fistula were analyzed retrospectively.ResultsThree months to five years after the surgery, the 21 patients were assessed with pure-tone audiometry. In 12 cases, the difference between the postoperative and preoperative bone-conduction threshold averaged across 0.5, 1, 2 and 4 kHz was less than 5 dB HL. The hearing of 3 patients was improved as compared with that before the surgery, while the hearing of 5 patients deteriorated. One patient received cochlear implantation 3 months after the first tympanoplasty. For the 11 patients treated with tympanoplasty and canal wall down mastoidectomy, there was no significant difference in the average bone- and air-conduction thresholds(0.5, 1, 2,4 and 8 kHz) before and after the surgery(P>0.05).Conclusion There is no significant change in the bone-conduction hearing thresholds for patients with middle ear cholesteatoma and labyrinthine fistula after the surgery, so tympanoplasty should be performed to preserve the hearing if possible.

目的 研究庆大霉素耳毒性模型大鼠耳蜗凋亡诱导因子(apoptosis-inducing factor,AIF)表达及阿司匹林的拮抗作用.方法 20只SD大鼠随机分为阿司匹林(acetylsalicylic acid,ASA)+庆大霉素(GM)组(ASA+GM组)和庆大霉素组(GM组),每组各10只动物,GM组腹腔注射GM 120 mg·kg-1·d-1,连续21天,ASA+GM组先给予ASA 100 mg·kg-1·d-1灌胃,1小时后皮下注射等剂量GM,连续21天;两组动物分别于用药前、用药第7、14、21 d行ABR检测,并于用药21 d后进行耳蜗毛细胞计数及免疫荧光染色观察两组大鼠耳蜗AIF表达.结果 用药第7、14、21 d ASA+GM组ABR反应阈均低于GM组(P＜0.05);用药21 d时ASA+ GM组耳蜗毛细胞缺失率为7.20％,明显低于GM组(21.51％)(P＜0.05),且在两组耳蜗毛细胞亡处均见AIF高表达.结论 阿司匹林能拮抗庆大霉素的耳毒性,庆大霉素损伤耳蜗外毛细胞时AIF参与了细胞的凋亡.

OBJECTIVE:Retrospectively analyzed the influences of preoperative acoustic immittance pressure balance tests and intraoperative wet ear findings in myringoplasty surgery results.METHODS:One hundred and twenty-one chronic suppurative otitis media patients underwent myringoplasty surgeries were included and divided into functional group and non-functional group according to preoperative acoustic immittance pressure balance tests. Meanwhile, cases were divided into dry ear group and wet ear group according to intraoperative findings. Postoperative hearing improvement and perforation rate were compared between the two groups.RESULTS:Functional group had 72 cases, including 58 dry ears and 14 wet ears. Non-functional group had 46 cases, including 19 dry ears and 27 wet ears. Postoperative hearing improvement rate in functional group was 85.5% (59/69), and 72.1% (31/43) in non-functional group (χ(2) = 2.230, P = 0.093). Perforation rate in functional group was 16.7% (12/72), significant higher when compared with 2.2% (1/46) in non-functional group (χ(2) = 4.626, P = 0.015). Postoperative hearing improvement rate in dry ear group was 85.3% (64/75), and 71.8% (28/39) in wet ear group (χ(2) = 2.213, P = 0.085) . Perforation rate in dry ear group was 12.8% (10/78), and 7.0% (3/43) in wet ear group (χ(2) = 0.472, P = 0.377).CONCLUSIONS:Non-functional result of preoperative acoustic immittance pressure balance test had significant relationship with the intraoperative wet ear findings. It may result in lower postoperative hearing level, and lower perforation rate. Large sample studies should be carried out in future.

ObjectiveTo review treatment outcomes of revision surgery in chronic suppurative otitis media by compar ing postoperative assessment findings between revision and first surgery.MethodsData from 16 patients(16 ears) who under went revision surgery operated by the corresponding author were reviewed. Sixteen separate cases with matched age,history of disease,gender and surgical method were chosen for a paired analysis. The 32 patients were followed up to assess postopera tive complications for at least 3 months and their pre- and postoperative pure tone threshold results were documented. Postop erative mean air-bone gap(ABG) ≤20dB and air conduction gain(ACG) ≥10dB were set as evaluation standards.Results7 pairs underwent simple tympanoplasty,9 pairs underwent tympanoplasty and canal-wall-down mastoidectomy. The percent age of postoperative mean ABG ≤20dB was 43.8% after revision surgery compared with 68.8% after first time surgery(P= 0289). The percentage of ACG≥10dB after revision surgery was 62.5% compared with 50.0% after,first time surgery(P= 0.754). The percentage of ABG ≤20dB and ACG≥10dB was 31.3% after revision surgery compared with 43.8% after first time surgery(P=0.687). No postoperative complication was found in either group.ConclusionPostoperative recrudescence or failed hearing improvement can be operative indications for tympanoplasty. Revision surgery is an effective treatment to clear lesions and improve hearing outcomes.

目的:利用针对B7-H1的siRNA在脑胶质瘤U87细胞中下调B7-H1的表达,研究B7-H1的表达下调对U87细胞增殖和凋亡的影响.方法:根据人B7-H1的mRNA序列设计并合成两对针对B7-H1的siRNA,于转染前一天将U87细胞接种于10 cm细胞培养皿中,以转染时细胞融合度为50％-80％为宜,分别用250 μ10PTI-MEM稀释15μl siRNA与15μl转染试剂Lipofectamine 2000,将两者混匀室温静置20 rin后,滴入细胞培养皿中.转染60或72 h后利用流式细胞术检测B7-H1在细胞表面的表达情况,利用荧光定量PCR和Western Blot分别检测B7-H1的mRNA和蛋白质水平,并用MTT和流式细胞术检测B7-H1表达下调后,U87细胞增殖和凋亡的改变.结果:与阴性对照组相比,两对针对B7-H1的siRNA均可有效下调U87细胞中B7-H1的表达,流式细胞术结果显示与阴性对照组相比,B7-H1阳性表达率由53.2％分别下调至26.7％和20.6％；MTT结果显示B7-H1表达下调后U87细胞的增殖被显著抑制,培养第5天吸光度值由0.58±0.02分别下降至0.451 ±0.02及0.342±0.016；流式细胞术结果显示B7-H1表达下调后U87细胞凋亡明显,早期凋亡率由0.1％分别增加至12.8％及13.2％.结论:B7-H1的表达下调可有效抑制脑胶质瘤U87细胞的增殖,并促进细胞凋亡,提示B7-H1可能作为脑胶质瘤基因治疗的一个潜在靶点.

Objective: To study the expression of tumor necrosis factor receptor type Ⅰ( TNFR-Ⅰ) in the rat carotid body( CB),and the effect of TNF-α on intracellular Ca2 +( [Ca2+]i) level in the glomus cells of the rat CB. Methods: Western Blot and double immunofluorescent double staining methods were used to investigate the expression of TNFR-Ⅰ in the rat CB. Calcium imaging was used to observe the effect of TNF-α on [Ca2+]i level in the glomus cells of the rat CB. Results: The result of Western Blot shwed that TNFR-Ⅰ protein band appeared at 55 kD,consistent with the molecular weight of the receptor. The result of double immunofluorescent staining showed that TNFR-Ⅰ was expressed in the CB glomus cells. The result of calcium imaging showed that extracellular application of TNF-α induced a rise in [Ca2+]i level in the cultured glomus cells of the rat CB. Conclusion: TNFR-Ⅰ is strongly expressed in the glomus cells of the rat CB,and the glomus cells can sense the stimulation of proinflammatory cytokine TNF-α.

OBJECTIVE:To design and package shRNA expressing lentiviral particles targeting B7-H1, and evaluate their inhibitory effect on B7-H1 expression in U251 cells.METHODS:Three shRNAs targeting B7-H1 was designed and the sense and antisense primers were produced by chemical synthesis. After annealing, they were linked into restriction enzyme digested pLKO.1 vector. Confirmed by DNA sequencing, the lentiviral particles were packaged and applied to infect U251 cells. qRT-PCR and Western blotting were used to detect the B7-H1 mRNA and protein levels respectively.RESULTS:qRT-PCR and Western blotting showed that two of the three shRNAs effectively knocked-down B7-H1 expression in U251 cells.CONCLUSION:The packaged lentiviral particles can specifically inhibit B7-H1 expression, which will be helpful for further functional study on B7-H1.

Objective: To investigate the effect of chronic hypoxia on the expression of Wnt-1 and β-catenin in the rat carotid body(CB).Methods: Forty male SD rats were randomly divided into 5 groups: the control group,chronic intermittent hypobaric oxygen stimulation for 1,2,3 and 4w groups.The expression of Wnt-1 and β-catenin in rat carotid body were detected by Western Blot.Results: There was no significant difference for the expression of Wnt-1 in rat CB between the hypoxia 3 w group and the hypoxia 4 w group(P > 0.05).However,there was significant difference for the expression of Wnt-1 in rat CB between the other groups(P<0.05).The expression of β-catenin in the CB of the rats exposed to hypoxia for 3 w was up-regulated compared with that in the control group(P<0.05).Conclusion: The results suggest that Wnt/β-catenin signal pathway may be involved in chronic hypoxia-induced carotid body stem cell proliferation and differentiation processes.

[目的]观察实验性自身免疫性脑脊髓炎(EAE)发病高峰期淋巴细胞表面B7-H1分子的表达变化,探讨B7-H1在EAE发病和病情进展中的作用.[方法]以MOG35-55诱导雌性C58BL/6小鼠制备EAE动物模型,并对其行为学变化进行记录与评分.分别于发病前和发病高峰期处死小鼠,分离脾脏与中枢神经系统中的淋巴细胞,用流式细胞术分析淋巴细胞表面B7-H1分子的表达差异.[结果]与发病前相比,EAE发病高峰期脾脏分离的淋巴细胞中B7-H1阳性细胞率由(35.1±2.46)％下降至(18.9±2.06)％(P＜0.01),其中CD4+T细胞中B7-H1阳性细胞由发病前的(6.4±1.25)％下降至发病后的(2.3±1.04)％(P＜0.05).中枢神经系统浸润的淋巴细胞中有8.7％为B7-H1阳性细胞.[结论]在EAE发病过程中,B7-H1分子在外周淋巴细胞的阳性细胞数下降,而中枢神经系统浸润的淋巴细胞中有一定比例的B7-H1阳性细胞,提示B7-H1可能在EAE发病过程中发挥重要作用.

神经科学的特点是多学科高度交叉并且发展迅速。针对此特点,为避免传统的教学模式对神经科学基础二教学的严重束缚,把传统的教学模式和西方建构主义理论教学模式的优势结合起来,既发挥教师的主导过程,又兼顾学生是学习的主体,充分调动学生的主动性和创造性,收到了很好的教学效果。

考试作为一种评估手段,在检验"教"与"学"双方质量上发挥着不可替代的作用.因此,考试被当做一种"指挥棒", 师生双方都围之起舞.随着以素质教育为中心,以培养创新性人才为宗旨的高教改革的深入,在我国高等教育的反思中,考试制度未能"与时俱进"也逐渐受到学者关注,考试改革的呼声日渐增高.我们就基于问题(problem-based)的神经生物学教学和考试改革进行探索.从2004年起在我校本科生的神经生物学教学中探索并实施"基于问题"的创新性教学模式.

The traditional examination mode has many shortcomings and it is not beneficial to the development of the students' creativity.Besides,it is not suitable for the teaching.In problem-based neurobiology teaching,we explored a new examination method which was beneficial for promoting the creativity and independent thinking of the students.

Objective To study the expressions of IL-1 receptor type Ⅰ(IL-1RI) mRNA and IL-1β protein in the rat carotid body. Methods In situ hybridization,immunofluorescence double staining and Western blotting methods were used. Results The result of in situ hybridization showed that the positive signal of IL-1β mRNA was mainly located in the glomus cells of the carotid body.The result of immunofluorescence double staining showed that IL-1β protein also expressed in the glomus cells of the organ.The Western blotting proved that the IL-1β immunoreactive band appeared at 18kD,consistent with the molecular weight of the cytokine.Conclusion The glomus cells of the rat carotid body not only express IL-1RI mRNA,but also IL-1β.

Objective To investigate the effect of stress induced by water restriction on the level of phosphorylated(ERK1/2) in rat brain. Methods Fifty-eight male Wistar rats were used and randomly divided into control group(C,n=4) and three experimental groups: TW(drinking at scheduled time),EB(empty bottle stimulus),WR(restricted water drinking),which were subdivided into three subgroups by time as 3d,7d, 14d(n=6 for each).In C group,water was freely accessed to the animal for one week.In the experimental groups the water supply was restricted following a week of accommodation and the other week for timed water supply training.In TW group,the water was supplied twice a day and 10 min for each in a fixed time. In EB and WR groups,the water was served only once a day for 10 min,and in the other scheduled time for water supply only an empty bottle without water was provided in the EB group and water was limited in the WR group.All the animals were deeply anesthetized 1h after the last stimulus and transcardially infused,then the brains were cut into free-floating sections and processed for immunohistochemical staining of pERKI/2 with ABC method.The expression of pERK1/2 positive staining was measured with image analysis system. Results The area of phosphorylated ERK1/2 was significantly increased in many brain structures,especially in paraventricular hypothalamic nucleus(PVN),supraoptic nucleus(SON),ventrolateral septum(LSV),medial amygdaloid nucleus(MeA),central amygdaloid nucleus(CEA) and nucleus of solitary tract(NTS) in TW,EB and WR group compared with C group.The expression of phosphorylated ERK1/2 in SON,LSV, MeA and CeA in EB and WR group were higher than that in TW group;pERK1/2 expression of LSV,MeA,CeA and NTS in EB group increased and went down more early and quickly than that in WR group.The response of phosphorylated ERK1/2 was dependent on both stimulus methods and time in all the nuclei mentioned above except PVN,in which only the stimulus time was related. Conclusion The level of pERK 1/2 was significantly altered in PVN,SON,LSV,MeA,CeA and NTS following stimulation of water restriction.The results indicate that the activated nuclei in the brain by physical and psychological stressors are different.

Objective: To observe the effects of chronic hypoxia and systemic rmIL-1β injection on the expression of IL-1 receptor type Ⅰ(IL-1RⅠ) in the rat carotid body.Methods: Adult male Sprague-Dawley rats were divided into 4 groups: rats in T1 group were exposed to hypoxia and intravenously injected with rmIL-1β;in T2 group were only exposed to hypoxia;in T3 group were only injected with rmIL-1β;and in T4 group were only exposed to normoxia.Immunohistochemistry and semiquantitative analysis of IL-1RⅠ were done in the carotid body sections of all rats.Results: The expression of IL-1RⅠ in the carotid body in T2 and T3 groups were up-regulated in comparison with that in T4 group.The expression of IL-1RⅠ in the carotid body in T1 group was more than those of T2 and T3 groups.Statistic anylysis showed that there was no interaction between hypoxia and rmIL-1β.Conclusion: Both chronic hypoxia and IL-1β can up-regulate the expression of IL-1RⅠ in the carotid body;the combination of these 2 factors can more obviously enhance the expression of IL-1RⅠ,but there is no synergistic or antagonistic effect between hypoxia and rmIL-1β.

The enhanced production of nitric oxide (NO) via inducible nitric oxide synthase (iNOS) has been implicated in the pathogenesis of neuronal apoptosis after acute traumatic spinal cord injury (SCI). In the present study, to further characterize the pathways mediating the synthesis and release of NO, we examined activation of extracellular signal regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinases (p38 MAPK) in microglia/macrophages in the injured area of adult rats subjected to a complete transection at the T10 vertebrae level and assessed their role in NO production and survival of neurons by using immunohistochemistry, Western blot, RT-PCR and pharmacological interventions. Results showed activation of microglia/macrophages featured by morphological changes, as visualized immunohistochemically with the marker OX-42, in the areas adjacent to the lesion epicenter 1 h after surgery. Concomitantly, iNOS mRNA and its protein in the activated microglia/macrophages were also significantly upregulated at early hours after surgery. Their levels were maximal at 6 h, persisted for at least 24 h, and returned to basal level 72 h after SCI. Furthermore, phosphorylated ERK1/2 and p38 MAPK were activated as well in microglia/macrophages in injured area with a similar time course as iNOS. With administration of l-NAME, a NOS inhibitor, the number of apoptotic neurons was clearly decreased, as assessed with TUNEL method at 24 h after SCI. In parallel, loss of neurons induced by SCI, assessed with NeuN immunohistochemistry, was also diminished. Moreover, the effect of inhibition of phosphorylation ERK1/2 and p38 MAPK by corresponding inhibitors PD98059 and SB203580 administered before and after SCI was also investigated. Inhibition of p38 effectively reduced iNOS mRNA expression and rescued neurons from apoptosis and death in the area adjacent to the lesion epicenter; whereas the inhibition of ERK1/2 had a smaller effect on decrease of iNOS mRNA and no long-term protective effect on cell loss. These results indicate the ERK1/2 and p38 MAPK signaling pathway, especially the latter, play an important role in NO-mediated degeneration of neuron in the spinal cord following SCI. Strategies directed to blocking the initiation of this cascade prove to be beneficial for the treatment of acute SCI.

The effects of chronic hypoxia and intraperitoneal injection of recombinant murine interleukin-1β(rmIL-1β) on the expression of IL-1β in the carotid body were studied by using immunohistochemistry and image analysis. Twenty adult male Sprague-Dawley rats were used and divided into four groups. The rats in the T1 group were exposed to hypoxia and injected with rmIL-1β. The rats in the T2 group and T3 group were only exposed to hypoxia or injected with rmIL-1β, respectively. The rats in the T4 group were exposed to normoxia and not subjected to an injection of rmIL-1β. For producing hypoxia, the rats in T1 and T2 groups were exposed to hypobaric apparatus (PB=375 Torr) 9 h per day for consecutive 2 weeks. The rats in T3 and T4 groups were also placed in the apparatus but with a normoxia. At the thirteenth day, before placed in the hypobaric chamber, the rats in T1 and T3 groups received an intraperitoneal injection of rmIL-1β, while the rats in T2 and T4 groups, injection with saline. At the fourteenth day, after exposed to hypobaric hypoxia or normoxia in the chamber for 6 h, the rats in four groups received an injection of rmIL-1β or saline, then continued to be exposed to hypobaric hypoxia or normoxia in chamber for another 3 h and were killed. The results showed that the expression of IL-1β in the carotid body in the T2 group or the T3 group was up-regulated compared with that of the T4 group (P<0.05), and there was no interaction between hypoxia and intraperitoneal injection of rmIL-1β (P>0.05). The above results indicate that either the chronic hypoxia or pro-inflammatory cytokine stimulation can up-regulate the expression of IL-1β in the carotid body. IL-1β might play a role in regulation of carotid body function.