遗传性神经肿瘤综合征:21世纪神经外科医师必须面对的疾病

本刊在国内首次对常见的遗传性神经肿瘤综合征从分子生物学与分子遗传学。临床表现及诊断标准，医学影像学，遗传咨询与分子遗传学检测，随访及医学处理等方面进行了系统的介绍。并报道了国内对遗传性神经肿瘤综合征所进行的部分基础与临床研究。以及典型病例分析。[第一段]     

关于临床判断致病性突变和无害突变的思考

<正>近年来,二代基因测序(NGS)技术的普及使诸多既往难以确定的、遗传异质性较强的疾病,如肌萎缩侧索硬化症(ALS)、腓骨肌萎缩症(CMT)、遗传性痉挛性截瘫(HSP)、脊髓小脑共济失调(SCA)、肢带型肌营养不良症(LGMD)等的致病性突变位点得以明确,为临床诊断与遗传咨询提供重要信息。然而,临床上常可以看到这样一种现象,临床医师在面对二代基因测序技术提供的遗传学信息时仍十分困惑,这是由于有些基因检测结果与临床表型     

国内抑郁症遗传学研究

遗传学常用的研究方法包括流行病学调查与分子遗传学研究。流行病学调查包括家系研究、双生子研究、寄养子研究，以及将与先证者有血缘关系亲属的患病率与人群患病率进行比较以推断疾病是否存在家族聚集性、遗传因素在疾病发生中的作用。分子遗传学研究是应用分子遗传学原理在基因水平分析疾病的易感性，包括连锁分析与关联分析。     

脊髓小脑性共济失调的症状前诊断研究

目的:探讨脊髓小脑性共济失调的症状前患者分子遗传学诊断及其面临的有关问题。方法:对临床诊断为脊髓小脑性共济失调(SCA)患者进行基因诊断的同时根据申请者要求检测其家系“健康”个体,采用聚合酶链反应(PCR)对三核苷酸重复(TNR)片段进行扩增,聚丙烯酰胺凝胶电泳并计算其长度,推算正常和异常扩增等位基因内TNR重复拷贝数。结果:多数家系无症状患者均要求进行致病基因突变检测。通过基因检测诊断出6例SCA3、2例SCA1、2例SCA12症状前患者。结论:分子遗传学检测可作出可靠的症状前诊断。进行遗传咨询应考虑医学、伦理、法律及社会诸多问题。     

重视神经肌肉病的临床遗传咨询

近年研发的一些针对某些神经肌肉病的特异性基因治疗和酶替代治疗方法,使越来越多的咨询者将咨询重点由再生育风险转变为治疗,这就要求临床遗传咨询师对所咨询的疾病有相当的知识储备,方能与咨询者进行交流,并推动临床遗传咨询的发展。因此,有必要强调临床遗传咨询师熟练掌握确诊和遗传咨询的详细步骤,并提出对临床遗传咨询师的基本要求。     

脊髓小脑性共济失调症状前诊断的初步研究

目的:探讨脊髓小脑共济失调症状前患者的分子遗传学特征及其面临的相关问题。方法:对临床诊断为脊髓小脑共济失调的家系“健康”成员,采用聚合酶链反应(PCR)对三核苷酸重复(TNR)片段进行扩增,荧光PCR、毛细管电泳技术计算其长度,推算出正常和异常扩增等位基因内TNR重复拷贝数。结果:通过基因检测诊断出4例SCA3、3例SCA2症状前患者。结论:对家系成员进行基因筛查,早期作出可靠的症状前诊断,加强随访,重视遗传咨询。     

脊髓小脑性共济失调2型的分子遗传学诊断及临床分析

目的:研究分析脊髓小脑性共济失调2型(SCA2)的分子遗传学诊断、应用以及临床表现特征。方法:对来自广西地区临床诊断为SCA的1个家系2例患者和8名"健康"家系成员,以及35名正常对照人员,通过聚合酶链式反应、琼脂糖电泳等技术检测SCA2基因位点内CAG三核苷酸重复扩增次数,并对异常等位基因片段进行DNA测序。结果:我国广西正常人群SCA2等位基因CAG重复数为20～29次,1家系中2例患者与1例症状前患者存在SCA2(CAG)n扩展突变,拷贝数分别为42、45、55次。结论:首次发现广西SCA2,利用分子遗传学分析可进行SCA2基因诊断,为症状前诊断及遗传咨询提供依据。     

中枢学习记忆功能相关基因

近几年随着遗传学和分子生物学等技术的迅速发展，使我们从基因水平对构成学习记忆基因的分子机制有了进一步的认识，这些研究表明，学习记忆过程所必需的许多分子和分子机制在进化过程中得到保存，多种基因及其产物可在细胞膜受体，胞质内信号转导通路级联成分，胞核内基因表达的转录调节以及细胞生长发育等多个层次与学习记忆的调控有关。本文仅就来自海兔，果蝇和啮齿类动物的与中枢学习记忆功能的有关的基因进行综述。     

数量性状位点在行为及精神病分子遗传学研究中的进展

数量遗传学的观点认为，人类的复杂行为大部分并不遵循孟德尔定律，而是与更加复杂的基因系统相关联，不仅如此，精神障碍也具有这样的遗传学基础。自从1975年Gelderman提出了数量性状位点(quantitative trait loci，QTLs)的概念后，在精神病分子遗传学领域的QTLs研究取得了迅速进展。所谓的QTLs足指参与控制某种数量性状、作用大小不完全相同而又相互协同和相互作用的基因系统。由这些基因系统决定的性状呈数量化分布，而不是“有”或“无”     

家族性双侧腕管综合征一家系分析并文献复习

目的分析家族性腕管综合征的临床表现、电生理、影像学及分子遗传学特点,尤其是遗传学的研究进展。方法收集家族性腕管综合征一家系中先证者的临床资料、实验室结果、电生理和影像学资料,同时对先证者、先证者之子以及家系中其他患病成员围绕周围神经病行基因学检测。结果家系中患病者均早年即出现典型的双侧腕管综合征,呈常染色体显性遗传模式。通过基因检测排除了合并有遗传性压力易感性周围神经病和家族性淀粉样变性的可能,同时发现了INF2、KIF1B、TRPV4、SCN9A这4个基因存在点突变。结论原发性家族性腕管综合征可能为其他基因异常引起的一种独立的疾病,然而其致病基因是未知的,仍有待我们进一步探索。     

Denervation study of synapses of organ of corti of old world monkeys

Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.     

Summary of legislation of 1935 of interest to the department of Mental Hygiene

Psychiatric Quarterly -     

Summary of legislation of 1941 of interest to the Department of Mental Hygiene

Psychiatric Quarterly -     

Asymmetry of on- and off-pathways of blue-sensitive cones of the retina of macaques

Macaque retinal ganglion cells whose receptive-field center recieves input from blue-sensitive cones show an overt asymmetry of the frequency of ON-center and OFF-center varieties, an asymmetry not present in ganglion cells whose center receives input from the other two cone types. A similar asymmetry of ON/OFF responses is found in the local electrotetinogram (d-wave) mediated by signals from blue-sensitive cones. ‘Blue-ON-center’ ganglion cells have larger receptive-field centers and shorter conduction latencies than other opponent-color varieties, suggesting an appreciable degree of receptor convergence and presumably large cell bodies. Intracellular stainings of these neurons with Procion Yellow show that they correspond to diffuse stratified (Parasol) ganglion cells whose flat-topped dendritic arborization stratifies in the sclerad half of the inner plexiform layer. In view of the known characteristics of macaque bipolar cells and of the ON/OFF asymmetry, it is proposed that these ganglion cells are postsynaptic to cone-specific flat bipolars possibly mediating sign-inverting synaptic contacts. The results also indicate a reversal, for the blue-cone pathway, of the ON/OFF lamination of the inner plexiform layer that has recently been described in other species.     

Mechanism of action of tubocurarine on nicotinic cholinoreceptors of neurons of the sympathetic ganglia of rats

Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.