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71.
Development of the vertebrate central nervous system is thought to be controlled by intricate cell-cell interactions and spatio-temporally regulated gene expressions. The details of these processes are still not fully understood. We have isolated a novel vertebrate gene, CRIM1/Crim1, in human and mouse. Human CRIM1 maps to chromosome 2p21 close to the Spastic Paraplegia 4 locus. Crim1 is expressed in the notochord, somites, floor plate, early motor neurons and interneuron subpopulations within the developing spinal cord. CRIM1 appears to be evolutionarily conserved and encodes a putative transmembrane protein containing an IGF-binding protein motif and multiple cysteine-rich repeats similar to those in the BMP-associating chordin and sog proteins. Our results suggest a role for CRIM1/Crim1 in CNS development possibly via growth factor binding.  相似文献   
72.
The comparative study has been carried out on hypothalamic neurohormone (proline-rich polypeptides-PRP) and synthetic glucocorticoid dexamethasone (DEX) protective properties at the systemic (i/m) administration. Both background and evoked electrical activity (on n.ischiadicus stimulation) of single neurons in the lumbo-sacral part (laminae II–VI and VII–VIII by Rexed) and field potentials (FP) of spinal cord were recorded during acute experiments on intact spinal rats, subjected to Vipera Raddei (VR) venom intoxication, and chronic spinal cord trauma (hemisection). The action of PRP was characterized by the pronounced activation of the background activity (BA) with adaptive effect, depending on dose and initial level of BA, by results of the statistical analysis. A high effect is received from comparatively small doses. For comparison it was used strong glucocorticoid DEX, possessing single-directed but less expressed excitative action on investigated spinal cord neurons. The initial increase of BA frequency with subsequent depression was the typical symptom of venom influence. A protective effect of preliminary PRP injection is revealed on the succeeding VR venom influence. Use of PRP and DEX causes the increase of reduced activity of neurons on the injury side of animals with spinal cord hemisection. It provides the possibility of the therapeutic utilization. It was revealed considerably more expressed PRP action on neurodegenerative process connected to spinal cord injury (in comparison with DEX). The influence of hormones was compared in identical conditions of experiments on non-injured (control) and injured sides. Taking into consideration revealed protection characteristic of PRP and also the ability of snake venom to stabilize and to prolong its action combined with these preparations, the assumption is made on prospective use of the specified combination in clinical practice.  相似文献   
73.
The action of PRP is characterized by the pronounced activation of the background activity (BA) of the brain spinal cord, and the degree of the activity depends on BA initial level. The typical peculiarity of Vipera raddei venom influence is the initial increase in frequency of BA with subsequent depression. A preliminary injection of PRP has a protective effect at subsequent influence of venom. In animals with hemisection the PRP increases the decreased activity of neurons on injury side. Taking into consideration the protective peculiarities of PRP in the relationship to snake venom and the possibility of the latter to stabilize and prolong the action of drugs (in the case of PRP) combined with them, it is supposed that the mentioned use of the combination in clinical practice will be perspective. The data obtained testify the PRP to be a neuroprotector against many toxic compounds formed in organism (glutamate, ceramid, beta-amyloid neurotoxisity, etc.). Investigations in this aspect are still in the process.  相似文献   
74.
Nerve growth factor (NGF) is crucial for the development of sympathetic and small-diameter sensory neurons and for maintenance of their mature phenotype. Its role in generating neuronal pathophysiology is less well understood. After spinal cord injury, central processes of primary afferent fibers sprout into the dorsal horn, contributing to the development of autonomic dysfunctions and pain. NGF may promote these states as it stimulates sprouting of small-diameter afferent fibers and its concentration in the spinal cord increases after cord injury. The cells responsible for this increase must be identified to develop a strategy to prevent the afferent sprouting. Using immunocytochemistry, we identified cells containing NGF in spinal cord sections from intact rats and from rats 1 and 2 weeks after high thoracic cord transection. In intact rats, this neurotrophin was present in a few ramified microglia and in putative Schwann cells in the dorsal root. Within and close to the lesion of cord-injured rats, NGF was in many activated, ramified microglia, in a subset of astrocytes, and in small, round cells that were neither glia nor macrophages. NGF-immunoreactive putative Schwann cells were prevalent throughout the thoracolumbar cord in the dorsal roots and the dorsal root entry zones. Oligodendrocytes were never immunoreactive for this protein. Therapeutic strategies targeting spinal cord cells that produce NGF may prevent primary afferent sprouting and resulting clinical disorders after cord injury.  相似文献   
75.
A Cell Culture Model for Androgen Effects in Motor Neurons   总被引:8,自引:2,他引:6  
Abstract: Androgens are known to alter the morphology, survival, and axonal regeneration of lower motor neurons in vivo. To understand better the molecular mechanisms of androgen action in neurons, we created a model system by stably expressing the human androgen receptor (AR) in motor neuron hybrid cells. Motor neuron hybrid cells express markers consistent with anterior horn cells and can be differentiated into a neuronal phenotype. When differentiated in the presence of androgen, AR-expressing cells, but not control cells, exhibit a dose-dependent change in morphology: androgen-treated cells develop larger cell bodies and broader neuritic processes while continuing to express neuronal markers. In addition, androgen promotes the survival of AR-expressing cells, but not control cells, under low-serum conditions. Our results demonstrate a direct trophic effect of androgens on lower motor neurons, mediated through the AR expressed in this population of neurons.  相似文献   
76.
77.
为研究代谢型谷氨酸受体各亚型在猫脊髓内的定位分布特征,本实验采用免疫组织化学方法调查了代谢型谷氨酸受体五种亚型(mGluR1,mGluR2,mGluR3,mGlur5及mGluR7)在猫脊髓(颈2、颈6、胸5、腰6、骶1-2)内的分布状况。结果如下:(1)在背角深层(Ⅲ-Ⅳ层)和腹角内分布有大量中小型(<30μm)mGluR1样免疫反应阳性神经元,背角浅层(Ⅰ、Ⅱ层)为阴性;(2)mGluR2/3样免疫反应阳性产物仅见于背角Ⅱ层内侧部,其它部位为阴性;(3)致密的mGluR5样免疫反应阳性产物主要分布于猫脊髓背角Ⅱ层的神经毯内,背角Ⅰ层及深层呈中等密度染色;(4)致密的mGluR7样免疫反应阳性产物分布于背角Ⅱ层的神经毯内,背角Ⅰ层及深层(Ⅲ-Ⅳ层)呈中等密度染色。此外,腹角运动神经元和骶髓副交感核内的神经元亦呈现mGluR7样免疫反应阳性。单侧切断背根,发现术侧背角浅层内mGluR7样免疫反应阳性产物密度略有降低,而mGluR5样免疫反应阳性产物密度与对侧基本相同。本研究结果显示代谢型谷氨酸受体五种亚型在所调查的猫脊髓各节段内(颈2、颈6、胸5、腰6、骶1-2)的分布存在差异,提示它们在介导谷氨酸传递的信  相似文献   
78.
本研究采用SDS凝胶电泳方法从人脊神经前根中分离出人脊髓前角运动神经元特有的蛋白—190KD。将该蛋白作为抗原,免疫BALB/c小鼠,经杂交瘤技术,获得了抗190KD蛋白的单克隆抗体。免疫细胞化学检测表明,190KD单抗与脊髓灰质前角神经元、前根及肌支发生阳性反应。实验结果提示,190KD蛋白分布在脊髓运动神经元胞体及脊神经的前根和肌支纤维中。  相似文献   
79.
Available epidemiological information on the associations between body anthropometry and the incidence of fractures in men is limited. We therefore prospectively investigated the association between body anthropometry and the incidence of hip and wrist fractures from low and moderate trauma among 43,053 men who were 40 years to 75 years of age in 1986 when they first enrolled in the Health Professionals Follow-Up Study. After 8 years of follow-up, 201 wrist fracture cases and 56 hip fracture cases were reported. Greater height was associated with significant elevations in both hip and wrist fractures, whereas nonsignificant inverse associations were observed with weight and body mass index. Men in the highest quintile of waist circumference had a relative risk (RR) of 2.57 (95% confidence interval [CI] 0.64 to 10.3) for hip fracture and 2.05 (95% CI 1.06 to 3.96) for wrist fracture when compared with men in the lowest quintile. Waist-to-hip ratio was also positively related to fracture incidence; comparing highest with lowest quintile, the RRs were 3.92 (95% CI 1.07 to 14.3) for hip fracture and 1.50 (95% CI 0.85 to 2.66) for wrist fracture. These anthropometric indicators, in particular waist-to-hip ratio, may be useful for the prediction of hip fracture in adult men.  相似文献   
80.
目的:比较锁定钢板(Locking plate,LP)与半肩关节置换(semi-shoulder arthroplasty,SSA)治疗老年肱骨近端NeerⅢ、Ⅳ型骨折临床疗效。方法:对我院骨科2009年5月至2013年5月收治的61例老年肱骨近端NeerⅢ、Ⅳ型骨折的患者资料进行回顾性分析,男性18例,女性43例,年龄60~84岁,平均69.3岁。其中采用LP治疗者40例,采用SSA治疗者21例,观察两组患者的手术时间、失血量、Neer评分情况,记录手术并发症情况,并进行统计学比较。结果:所有患者均获得随访,平均随访时间14.5个月(12~20个月)。LP组手术时间(105.6±20.4 min vs 80.6±18.2 min,t=2.650,P=0.01)多于SSA组,两组在手术出血量(188.5±25.2 ml vs 200.5±31.6 m L,t=1.666,P=0.1)、Neer评分优良率(92.5%vs 90.5%,X2=0.075,P=0.784)和并发症发生率(4.8%vs12.5%,X2=1.351,P=0.245)无明显差异。结论:在老年肱骨近端NeerⅢ、Ⅳ型骨折的治疗上,SSA手术时间短,但手术并发症发生率以及疗效优良率与LP相似,临床应根据病情及需要灵活选择手术方式。  相似文献   
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