α-共核蛋白异常积聚及其在帕金森病发病机制中的作用

帕金森病(PD)的主要病理改变为黑质多巴胺神经元变性和Lewy体形成.纤维化积聚的α-共核蛋白(ASN)是Lewy体的主要组成成分.研究证实ASN寡聚体具神经毒性,ASN异常积聚被认为在PD发病机制中发挥了关键作用.ASN的基因突变、过度表达、异常修饰或清除减少都可能引起其异常积聚.异常积聚的ASN通过刺激免疫反应、诱导多巴胺神经元凋亡、降低自噬作用、破坏高尔基体组成等途径导致多巴胺神经元变性.本文针对α-共核蛋白异常积聚的具体机制及其在帕金森病发病过程中的作用作一综述.     

帕金森氏病的治疗策略(英文)

帕金森氏病(Parkinson’s disease,PD)是由中脑黑质中多巴胺神经元变性,导致纹状体系统多巴胺(DA)含量下降引起的神经病变。其特征性症状包括震颤、僵硬和运动徐缓等。目前为止,帕金森氏病神经元死亡的病因仍不清楚。具体的神经变性机制包括自由基生成、氧化应激、线粒体异常、兴奋性中毒、钙中毒、营养因子不足、炎症过程、一氧化氮毒性和细胞调亡。这些因素相互增强形成恶性循环导致神经功能异常、萎缩,最终导致多巴胺神经元死亡。大量实验提示在PD病理过程中,自由基的生成和氧化应激起关键作用。目前,药物疗法并不能治愈PD。尽管左旋多巴(L-Dopa)替代疗法一直是控制PD症状的标准,但其只能缓解临床症状,并且L-Dopa长期治疗会引起多种副作用。目前尚无可行的疗法能遏制或减缓神经元变性。因此,研究不仅要致力于改善和延长L-Dopa对PD的治疗效果,还要研发兼具抗PD与神经保护功能的药物。本文综述了当前各种PD疗法的优缺点。这些疗法包括DA治疗、DA激动剂、单胺氧化酶-B抑制剂、儿茶酚-O-甲基转移酶抑制剂、抗谷氨酸药、胆碱能药物、外科手术(深部大脑苍白球或丘脑术)和干细胞移植术等。同时,基于PD病理过程,对未来的...     

铁在大鼠黑质多巴胺能神经元损伤中作用研究

目的：观察铁在多巴胺能神经元损伤过程中的作用，并探讨铁在帕金森病Parkinson disease，PD)起病阶段的作用。方法：通过PD大鼠模型，采用生化、TUNEL方法观察6-羟基多巴胺(6-OHDA)脑立体定向注射1、7、14、21d PD黑质铁浓度、自由基以及黑质细胞凋亡数变化。结果：1～21d PD大鼠黑质铁浓度、自由基及凋亡细胞数随时间增加而增加，并显著高于对照组。结论：铁在PD发病中具有重要作用。     

SNCA基因多态性与帕金森病

帕金森病(PD)在我国是仅次于Alzheimer病(AD)的神经系统变性疾病,＞ 65岁老年人的发病率为2％[1].其临床特征为运动迟缓、静止性震颤、肌强直及姿势、步态的异常;病理特征为黑质多巴胺能神经元的变性丢失及胞浆内嗜酸性包涵体即路易小体(LB)的形成.PD大多数是散发病例,家族性发病＜10％,遗传因素在家族性PD的发病机制中所起的重要作用已经成为共识.然而在过去的很长一段时间内认为散发性PD发病是环境因素而不是遗传因素在起作用[2].从1990年起,越来越多的研究结果确立了遗传因素在散发性PD发病中的重要地位.对PD的遗传学研究[2,3]发现,SNCA基因编码的α-突触核蛋白在PD发病中起了关键的作用.现对SNCA基因的多态性与PD发病的关系综述如下.     

帕金森病与免疫(综述)

帕金森病(PD)是一种常见的中老年人神经系统变性疾病。许多证据表明PD发病与免疫有关，包括抗神经结构的自身抗体和黑质中大量表达组织相容性糖蛋白(人类白细胞抗原-DR)的小胶质细胞的存在，PD患者外周血中细胞和体液免疫的异常，黑质纹状体多巴胺能区存在免疫反应．针对热休克蛋白的免疫球蛋白G的免疫活性增强．感染因素，免疫凋节因子等。目前尚不能确定PD发病中存在的免疫异常究竟是原发还是继发，开发免疫调节剂将给PD的治疗带来崭新前景。     

尿酸水平与帕金森病

帕金森病(Parkinson's disease,PD)是老年人神经系统常见的运动障碍性疾病之一,严重地影响着老年人的生活质量.PD的主要病理特征为中脑黑质致密部多巴胺能神经元的进行性变性减少,引起黑质纹状体系统多巴胺水平降低.尽管多巴胺能神经元选择性死亡的确切发病机制至今不明,流行病学、基础实验研究及临床资料证实由于接触一些毒素(如杀虫剂、1-甲基-4-苯基-1,2,3,6-四氢吡啶),含有抗氧化剂的饮食减少及体内尤其是黑质纹状体系统清除自由基物质水平的降低,而引起的氧化应激反应增强,线粒体功能障碍与PD的发病密切相联系[1-4].尿酸是一种重要的生理性的天然抗氧化剂、铁螯合剂、自由基清除剂.PD与尿酸的关系日益受到人们的重视.     

帕金森病黑质多巴胺能神经元铁死亡的机制研究

<正>帕金森病(Parkinson’s disease,PD)是一种常见于老年人的神经系统变性疾病,平均发病年龄为60岁左右。目前,在我国PD的患病率为1.7%且有逐年上升的趋势。PD最主要的病理改变是中脑黑质多巴胺(dopamine,DA)能神经元的变性死亡,进而引起纹状体DA含量显著性减少,导致一系列运动和非运动症状。研究表明PD患者黑质DA能神经元变性死亡主要是程序性细胞死亡,然而最新的研究发现一种以铁沉积为特征的非程序性细胞死亡同样发生于黑质DA能神经元,与PD的发生和发展密切相关。但是PD中铁沉积导致DA能神经元死亡的具体机制仍不清楚,本文从铁代谢失调、脂质过氧化、α-突触核蛋白异常聚集、炎症反应以及针对铁死亡的药物在PD治疗中的研究等几个方面进行综述。     

帕金森病全基因组关联研究进展

帕金森病(Parkinson's disease,PD)是黑质纹状体多巴胺神经元功能缺损,引起多巴胺能系统和胆碱能系统失衡的一种神经退行性疾病.发病率仅次于阿尔海默茨病(Alzheimer's disease,AD).1817年James Parkinsony医生首先对PD临床症状进行了描述,分别为:静止性震颤、肌强直和步态迟缓.PD病理特征主要为胞浆中出现包涵体(Lewy小体)[1].经历了近两个世纪的研究,对于PD发病机制有了一定了解,但是仍有许多未知.现在研究认为PD是基因、环境、环境-基因相互作用引起的复杂疾病.以往认为环境因素起主要作用,但是随着研究深入,逐渐认识到基因异常在PD发生中扮演重要角色.认识基因作用是从对家族性PD的研究开始的,通过研究一个具有常染色体显性遗传特征的意大利籍的家系发现了第一个家族性PD基因4q 21-q23/q-synuclein.     

Parkin与帕金森病的分子机制研究近况

帕金森病(PD)是常见的神经系统变性疾病,按发病原因可分为家庭型和散发型两类.现已在家庭性PD中确定了10个PD相关的基因座,并证实其中3个基因(α-synuclein,parkin,DJ-1)的突变分别导致了家庭性PD的发生.α-synuclein和Parkin基因的突变可能涉及PD患者脑内异常蛋白的生成与降解以及Lewy小体的形成,由此备受关注.近年来,学界逐渐认识到神经元内异常蛋白的产生和堆积可能是多巴胺能神经元死亡的关键所在.随着泛素-蛋白酶体系统在神经变性病中的作用被逐渐认识,Parkin作为泛素-蛋白酶体系统中重要的E3连接酶,也随之再度成为研究的热点.现就Parkin的研究现状及进展做一简要回顾.     

线粒体功能异常在帕金森病发病机制中的研究进展

帕金森病(PD)主要的病理改变为中脑黑质多巴胺能神经元变性丢失及α-突触核蛋白的沉积。多数研究认为,线粒体功能障碍、氧化应激、蛋白质异常修饰及错误折叠等机制导致的多巴胺能神经元功能紊乱是PD发病的核心机制。环境因素或基因突变导致的线粒体复合物I功能缺乏可以引起多巴胺能神经元选择性损伤,导致患者出现认知功能异常及运动障碍。线粒体功能障碍在PD发病的早期即已出现,被认为是散发性和单基因遗传性PD的共同特征。本文就线粒体功能异常分别在遗传性PD和散发性PD发病机制中的作用做一综述。     

Mechanisms of the suppression of the nociceptive reflex of the opening of the mouth during stimulation of the structures of the limbic brain

The comparative effectiveness of the inhibitory influence of tetanic stimulation of hypothalamus, amygdala and limbic cortex on EMG-response of m. digastricus evoked by electrical stimulation of tooth pulp nociceptive afferents was studied in cats anesthetized with a mixture of chloralose and nembutal. It was found that inhibition of the EMG-component of the jaw-opening reflex is most pronounced in case of stimulation of medial and lateral region of the hypothalamus, the inhibitory effect of central and medial nuclei of the amygdala is less pronounced and the effect of the limbic cortex is the weakest. It was shown that the mechanism of the antinociceptive effect of tetanic stimulation of the hypothalamus is not related to the concomitant increase of the blood pressure. After stabilization of the blood pressure the suppressive effect of the hypothalamus remains without changes, that points out to a direct, primary, not baro-afferent mechanism of the inhibition of the activity of nociceptive neurons of the trigeminal sensory nuclei. Noradrenaline, injected intravenously, induced a large increase of the blood pressure accompanied by a pronounced inhibition of the pain reflex. Angiotensin causes the same degree of blood pressure elevation without changes in the amplitude of the EMG-response of the pain reflex. Hypothalamic and noradrenergic mechanisms for control of pain sensitivity are discussed.     

药物治疗与合并认知行为治疗对强迫症疗效的比较

目的探讨认知行为心理治疗(CBT)在强迫症(OCD)患者各亚型治疗中的有效性和规律性。方法本研究为临床对照研究。符合入组标准的强迫症患者按患者自愿原则分为两组,治疗观察3、6、12个月。疗效评定分别运用Yale-Brown强迫量表,自拟的自评好转程度量表和临床疗效评定。结果认知行为心理治疗合并药物治疗组31例,临床有效率70.9%,其中治愈率1.8%。单纯药物治疗组24例,临床有效率33.3%。Yale-Brown强迫量表和自评量表得分在6个月和12个月两组有显著差异(P<0.05)。其中强迫症亚型(怕脏型、反复检查型和反复担心型)的疗效比较,怕脏型在治疗3个月末两组间自评量表评分有显著性差异(P<0.05);反复担心型在治疗6个月末两组间Yale-Brown强迫量表总分有显著性差异(P<0.05);反复检查型两组间无统计学差异。结论认知行为心理治疗合并药物治疗强迫症的疗效明显优于单纯药物治疗。强迫症的亚型在治疗中的有效性次序为:反复担心型>怕脏型>反复检查型。     

Characteristics of the sympathetic innervation of the nictitating membrane and of the vasculature of the nose and tongue of the cat

Summary Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves.Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue, whose activity was revealed after-receptor blockade, had a similar threshold to the vasoconstrictor fibres.Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa.The preganglionic compound nerve action potential had four major components, S₁–S₄. S₁, S₂ and usually S₃ fibres were associated with membrane contraction; S₂, S₃ and sometimes S₁ fibres were associated with nasal vasoconstriction; and S₃, usually S₂ and occasionally S₁ fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S₄ fibres, may include fibres associated functionally with the three effectors.There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions.     

Development of the projection from the nucleus of the brachium of the inferior colliculus to the superior colliculus in the ferret

Neurons in the deeper layers of the superior colliculus (SC) have spatially tuned receptive fields that are arranged to form a map of auditory space. The spatial tuning of these neurons emerges gradually in an experience-dependent manner after the onset of hearing, but the relative contributions of peripheral and central factors in this process of maturation are unknown. We have studied the postnatal development of the projection to the ferret SC from the nucleus of the brachium of the inferior colliculus (nBIC), its main source of auditory input, to determine whether the emergence of auditory map topography can be attributed to anatomical rewiring of this projection. The pattern of retrograde labeling produced by injections of fluorescent microspheres in the SC on postnatal day (P) 0 and just after the age of hearing onset (P29), showed that the nBIC-SC projection is topographically organized in the rostrocaudal axis, along which sound azimuth is represented, from birth. Injections of biotinylated dextran amine-fluorescein into the nBIC at different ages (P30, 60, and 90) labeled axons with numerous terminals and en passant boutons throughout the deeper layers of the SC. This labeling covered the entire mediolateral extent of the SC, but, in keeping with the pattern of retrograde labeling following microsphere injections in the SC, was more restricted rostrocaudally. No systematic changes were observed with age. The stability of the nBIC-SC projection over this period suggests that developmental changes in auditory spatial tuning involve other processes, rather than a gross refinement of the projection from the nBIC.     

A contribution to the study of the architecture of the autonomic nervous system of the digestive tract of the rat

Summary The distribution of aminergic and non-aminergic nerve fibres to the different constituents of the wall of the digestive tract in various regions is described. Aminergic fibres synapse with all nervous perikarya. Densely interlacing networks of nerve fibres are found in both layers of the tunica muscularis and in the lamina muscularis mucosae. A finely meshed plexus is observed in relation to the wall of the blood vessels in the wall of the gut. There are many fibres connecting the muscular and the vascular plexus. No nerve fibres have been observed in direct relation to the epithelium.The functional implications of these findings are discussed.