Ventrally emigrating neural tube cells migrate into the developing vestibulocochlear nerve and otic vesicle

Virtually all cell types in the inner ear develop from the cells of the otic vesicle. The otic vesicle is formed by the invagination of non-neural ectodermal cells known as the otic placode. We investigated whether a recently described cell population, originating from the ventral part of the hindbrain neural tube known as the ventrally emigrating neural tube (VENT) cells, also contributes cells to the otic vesicle. The ventral hindbrain neural tube cells were labeled with the fluorescent vital dye DiI or replication-deficient retroviruses containing the LacZ gene in chick embryos on embryonic day 2, after the emigration of neural crest from this region. One day later, the labeled cells were detected only in the hindbrain neural tube. Shortly thereafter, the labeled cells began to appear in the eighth (vestibulocochlear) cranial nerve and otic vesicle. From embryonic day 3.5-5, the labeled cells were detected in the major derivatives of the otic vesicle, i.e. the endolymphatic duct, semicircular canals, utricle, saccule, cochlea, and vestibulocochlear ganglion. That the emigrated cells originated from the ventral part of the hindbrain neural tube was confirmed by focal application of DiI impregnated filter paper and with quail chimeras. It is concluded that, in addition to the otic placode cells, the otic vesicle also contains the ventrally emigrating neural tube cells, and that both cell populations contribute to the structures and cell types in the inner ear. It is well known that inductive signals from the hindbrain are required for the morphogenesis of the inner ear. The migration of the hindbrain neural tube cells into the otic vesicle raises the possibility that the inductive effect of the hindbrain might be mediated, at least in part, by the ventrally emigrating neural tube cells and that, therefore, a mechanism exists that involves cells rather than diffusible molecules only.     

真皮下血管网皮瓣的过氧化脂质测定

对12只豚鼠背部随意型真皮下血管网皮瓣的过氧化脂质含量进行了动态观测.结果表明,过氧化脂质的含量与皮瓣损伤程度呈同步变化;与皮瓣血运重建的时间密切相关.氧自由基对皮瓣组织的损伤主要发生在移植后1～5天.     

人参皂甙Rg1对大鼠局灶性脑缺血脑组织神经干细胞增殖的影响

目的 观察人参皂甙Rg1对大鼠局灶性脑缺血脑组织神经干细胞增殖的影响,探讨其在脑保护及抗衰老作用中的可能机制.方法 取成年雄性Wistar大鼠,用线栓法制作大鼠大脑中动脉闭塞(MCAO)模型,采用脉冲标记法,经腹腔注射5′-溴脱氧尿苷(BrdU)标记处于增殖状态的神经干细胞,用免疫组织化学单标及双标免疫荧光技术观察人参皂甙Rg1对局灶性脑缺血后BrdU和巢蛋白(nestin)的免疫活性及nestin/BrdU双标阳性细胞的影响,镜下观察脑内神经干细胞的分布,并计数行定量分析.结果 局灶性脑缺血后大鼠室管膜下区及海马齿状回有nestin、BrdU及nestin/BrdU双标免疫阳性细胞分布.应用人参皂甙Rg1后,上述各部位阳性细胞数明显增多,与缺血组之间有显著性差异(P＜0.01).结论 人参皂甙Rg1具有促使神经干细胞增殖的能力,这可能是其神经保护及抗衰老作用的机制之一.     

Neuropathology of schizophrenia: A mini review

The neuropathology of schizophrenia remains obscure despite the fact that many neuropathologists have investigated this area for over 100 years. While remarkable progress has been made in the neuropathological study of neurodegenerative diseases including Alzheimer's disease, progress in studying the neuropathological entity of schizophrenia has not kept pace; the phrase “schizophrenia is the graveyard of neuropathologists” has been stated in the field. Since the 1980s, the morphological or functional abnormalities in the brains of schizophrenia patients have been reported by means of CT or MRI and with advanced functional brain image technology such as positron emission tomography or single photon emission computed tomography. Results from such imaging studies have led to neuropathological examination of the post mortem brains of schizophrenia patients being undertaken again. These neuroimaging studies have influenced the neuropathological investigation of the schizophrenic brain. Not only the classical microscopic observation of neuropathology, but also measurement and statistical analysis using computer imaging software or using immunohistological techniques has been performed. Based on the neuropathological studies of schizophrenia over the last 20 years, it is clear that schizophrenia is not a pure functional disease without organic factors. Reports of neuropathological abnormalities in the post mortem schizophrenic brain indicated they were found in almost all areas of the brain, but there are more reports describing the temporal lobe and frontal lobe compared to those describing other areas of the brain. These observed neuropathological abnormalities are explained rationally by the hypothesis of a neurodevelopmental disorder in this disease. In recent molecular biology studies, several putative candidate genes were reported, and some of these genes might have the function of neurodevelopment or making neuronal networks. It is important to consider together these findings with morphometric studies in neuropathological observation, neuroimaging studies and genome studies to pursue the etiology of schizophrenia from various perspectives.     

论网络化时代电视教材的重要性

针对教学实践中重视计算机辅助教学忽视电视教材的倾向，本文通过对网络时代中电视教材的作用和地位的分析，阐述了加强计算机辅助教学的必要性和加强电视教材制作及应用的重要性以及二者间的关系。     

基于网络环境下的教学设备管理信息系统

本文介绍了教学设备网络管理系统模型及其技术指标、软硬件环境、功能、程序设计和主要特点。     

Labeling efficacy of superparamagnetic iron oxide nanoparticles to human neural stem cells: comparison of ferumoxides, monocrystalline iron oxide, cross-linked iron oxide (CLIO)-NH2 and tat-CLIO.

OBJECTIVE: We wanted to compare the human neural stem cell (hNSC) labeling efficacy of different superparamagnetic iron oxide nanoparticles (SPIONs), namely, ferumoxides, monocrystalline iron oxide (MION), cross-linked iron oxide (CLIO)-NH(2) and tat-CLIO. MATERIALS AND METHODS: The hNSCs (5 x 10(5) HB1F3 cells/ml) were incubated for 24 hr in cell culture media that contained 25 microg/ml of ferumoxides, MION or CLIO-NH(2), and with or without poly-L-lysine (PLL) and tat-CLIO. The cellular iron uptake was analyzed qualitatively with using a light microscope and this was quantified via atomic absorption spectrophotometry. The visibility of the labeled cells was assessed with MR imaging. RESULTS: The incorporation of SPIONs into the hNSCs did not affect the cellular proliferations and viabilities. The hNSCs labeled with tat-CLIO showed the longest retention, up to 72 hr, and they contained 2.15+/-0.3 pg iron/cell, which are 59 fold, 430 fold and six fold more incorporated iron than that of the hNSCs labeled with ferumoxides, MION or CLIO-NH(2), respectively. However, when PLL was added, the incorporation of ferumoxides, MION or CLIO-NH(2) into the hNSCs was comparable to that of tat-CLIO. CONCLUSION: For MR imaging, hNSCs can be efficiently labeled with tat-CLIO alone or with a combination of ferumoxides, MION, CLIO-NH(2) and the transfection agent PLL.     

碱性成纤维细胞生长因子治疗猫急性脑梗死的作用机制研究

目的:观察碱性成纤维生长因子(bFGF)处理的缺血再灌注不同时程的猫脑组织中微管相关蛋白(MAP-2)和神经丝蛋白(NTP)的表达,探讨bFGF治疗缺血性脑损伤的可能作用机制。方法:健康家猫30只,随机分为生理盐水对照组和bFGF治疗组。采用左侧眼眶入路制作大脑中动脉缺血再灌注模型。于术前和再灌注24h、48h和7d,采用Philip的猫脑缺血神经功能评分标准进行神经功能缺损评分;应用免疫组织化学SP法检测缺血再灌注不同时程的脑组织MAP-2及NTP蛋白表达,进行免疫阳性细胞计数。结果:缺血再灌注48h后,治疗组动物神经功能受损程度较对照组明显减轻,MAP-2及NTP蛋白阳性细胞数目较对照组也显著增加。结论:bFGF通过诱导MAP-2及NTP蛋白的表达,减轻了缺血再灌注脑组织的神经元损伤和促进了神经纤维生长,从而改善受损的神经功能。     

多媒体网络教学的构成及其解决方案

作为一所教学医院，如何更好的提供教学服务，培养出高质量的军事医疗人员，在未来的战争中做好医疗保障是我们教学的目标。利用计算机多媒体网络技术将临床、科研和教学有效的组织起来，为优化教学内容、提高教学质量奠定了基础。