变性高效液相色谱法在家族性阿尔茨海默病突变位点检测中的应用

目的 通过对一个阿尔茨海默病（Alzheimer disease,AD)大家系突变位点的检测，探讨中国人家族性AD（familial Alzheimer disease,FAD)的发病机制，同时观察变性高效液相色谱法（denaturing high performance liq-uid chromatography,DHPLC)的实用价值。方法 应用DHPLC方法及DNA直接测序技术。对一个有130人的AD大家系和50名正常对照者进行了淀粉样蛋白前体（amyloid precursor protein,APP)基因，早老素1（prese-nilin1,PS1)基因的突变位点检测。结果 （1）5例AD患者及4例家系中的无痴呆症状者（Ⅳ-30,37,41,43)经DHPLC检测有PS1基因的第5外显子的突变峰，家系中其他成员无突变峰，PS1基因其他外显子检测及APP基因检测，家系中所有成员和正常对照组均无突变峰。（2）上述9例经DNA直接测序在PS1基因第5外显子的136号密码子发生了GCT→GGT错义突变，使丙氨酸变为甘氨酸（Ala136Gly)，无突变峰者DNA测序均未发现异常。结论 （1）DPLC检测显示出这-AD大家系PS1基因第5外显子存在突变，该突变位点可能为中国人FAD患者早老素基因突变点之一。（2）DHPLC技术可作为大样本筛查突变位点的一种便捷可靠手段。     

痴呆患者早老素-1基因第6号外显子突变研究

目的探讨痴呆患者早老素-1基因第6号外显子的突变特点。方法应用聚合酶链反应一单链构象多态性(PCR-SSCP)和DNA测序技术检测53例SAD患者、60例VD患者及90名健康老年人早老素-1基因第6号外显子。结果DNA测序在SSCP泳动异常标本中发现1123位点和1300位点发生错义突变，其中，SAD组2例在1123位点发生突变、2例在1300位点突变，VD组1例在1123位点发生突变；1123位点发生C→G突变(cys23Trp)，1300位点发生A→C突变(Asp 200Ala)。结论SAD患者存在早老素-1基因第6号外显子突变，本实验结果显示的2个突变位点均处在早老素蛋白的重要功能区，考虑此突变为病理性突变。     

散发性Alzheimer病早老素-1基因第8号和第10号外显子突变研究

目的 :探讨散发性 Alzheimer病 (SAD)与早老素 - 1(PS- 1)基因突变的关系。方法 :采用聚酶链反应 -单链构象多态性 (PCR- SSCP)分析技术对 6 8例 SAD患者的 PS- 1基因第 8号和第 10号外显子进行突变检测。结果 :所有病例 PS- 1基因第 8号外显子的 PCR- SSCP分析结果均两条单链和一条双链 ,第 10号外显子的 PCR- SSCP分析结果均显示三条单链和一条双链 ,未发现异常泳动 ,推断没有存在突变。结论 :SAD的致病原因与 FAD不同 ,PS- 1基因第 8号和第 10号外显子突变并非 SAD致病的重要原因     

散发性阿尔茨海默病早老素-1基因第5号和第8号外显子突变研究

目的　探讨散发性阿尔茨海默病 (SAD)与早老素 1(PS 1)基因突变的关系。方法　采用多聚酶链反应 单链构象多态性 (PCR SSCP)分析技术对 6 8例SAD患者的PS 1基因第 5号和第 8号外显子进行突变检测。结果　所有病例PS 1基因第 5号和第 8号外显子的PCR SSCP分析结果均显示两条单链和一条双链 ,未发现异常泳动 ,推断没有存在突变。结论　SAD和家族性AD(FAD)的致病原因存在差异 ,在SAD中PS 1基因第 5号和第 8号外显子不存在突变或突变率极低 ,并非SAD致病的重要因素     

家族性Alzheimer病淀粉样蛋白前体基因第16、17外显子的突变分析

目的:了解中国家族性Alzheimer病(familial Alzheimer disease,FAD)患者中21号染色体上淀粉样蛋白前体(amyloid precursor protein,APP)基因第16、17外显子的突变情况。方法:应用限制性片段长度多态性(restrictionfragment length polymorphism,RFLP)、聚合酶链反应-单链构象多态性(polymerase chain reaction-single strand con-formation polymorphsim,PCR-SSCP)及DNA直接测序技术,对两个FAD家系以及20例正常对照组进行了APP基因第16、17外显子检测。结果:全部家系成员及正常对照组经RFLP分析均存在EcoR Ⅰ酶切位点、BclⅠ消化后无Bcl Ⅰ多态性。经PCR-SSCP分析均未见异常泳动带。两个家系的全部成员及正常对照组经DNA序列分析也未见APP基因的缺失、插入和置换。结论:本研究中的两个家系中未发现APP基因第16、17外显子的突变,证实了APP基因突变所引起的FAD并不多见。     

早老素-1对阿尔茨海默病相关蛋白调节的可能途径

阿尔茨海默病（Alzheimer disease,AD)是成人痴呆症中最常见的一种,其中约105为显性遗传的家族性阿尔茨海默病（familial Alzheimer disease,FAD)。自从Sherrington首次报道早老素－1（presenilin-1,PS-1),并随后发现另1条与它高度同源的基因早老素－2（PS－2）以及药50％－80％FAD与它们突变有关以来,老素（PS）已成为AD研究的热点。但迄今为止,PS的功能尚不清楚。越来越多的语气表明,PS－1参与notch、wnt信息传导途径的调节,并藉此在AD发病中起重作用。     

阿尔茨海默病患者早老素-1基因5号外显子新突变点的研究

目的探讨早老素－１基因突变在散发性阿尔茨海默病（ＳｐｏｒａｄｉｃＡｌｚｈｅｉｍｅｒ′ｓｄｉｓｅａｓｅ,ＳＡＤ）患者发病机制中的作用。方法应用聚合酶链反应－单链构像多态性（ＰＣＲ－ＳＳＣＰ）及ＤＮＡ直接测序技术检测６８名ＳＡＤ患者、１３名血管性痴呆（ＶＤ）患者和６５名正常老年人的早老素－１基因第５号外显子。结果发现４名ＳＡＤ患者的ＰＣＲ产物ＳＳＣＰ分析发生泳动异常,ＤＮＡ序列分析发现：这４名ＳＡＤ患者的１３０号密码子发生了ＣＴＧ→ＡＴＧ错义突变（３８８位点发生Ｃ→Ａ突变）,使编码的氨基酸由亮氨酸变为蛋氨酸（Ｌｅｕ１３０Ｍｅｔ）;１５７号密码子发生了ＧＴＧ→ＣＴＧ错义突变（４６９位点发生Ｇ→Ｃ突变）,使编码的氨基酸由缬氨酸变为亮氨酸（Ｖａｌ１５７Ｌｅｕ）,另有１１名患者ＳＳＣＰ表现为一条单链增快,其性质待定。结论ＳＡＤ患者也存在早老素－１基因第５号外显子突变,该突变点可能为中国人ＳＡＤ患者早老素基因突变点之一。     

伴皮质下梗死及白质脑病常染色体显性遗传性脑动脉病的NOTCH3基因诊断

目的 分析伴皮质下梗死及白质脑病常染色体显性遗传性脑动脉病((CADASIL)的NOTCH3基因突变类型.方法 对临床诊断为CADASIL的4例先证者、来自3个家系10例患者及4例无类似临床表现成员、以及100名健康对照者进行NOTCH3基因PCR扩增及变性高压液相色谱分析(DHPLC)检测;对DHPLC阳性结果进行DNA双向测序,明确致病性突变或多态类型.结果 在CADASIL先证者及其家系患者中共发现134半胱氨酸→酪氨酸(Cys134Tyr)、141精氨酸→半胱氨酸(Arg141Cys)、90精氨酸→半胱氨酸(Arg90Cys)3种突变类型,存在于第3、第4外显子,为杂合错义突变.同时发现15种多态类型.其中家系1和家系2中分别发现1名成员与先证者存在相同位点的NOTCH3基因致病性突变,尚未出现与先证者相应的临床表现,被确定为临床前期患者.结论 NOTCH3单基因突变是CADASIL的分子遗传学基础,第3、4外显子可能是中国CADASIL家系的热点突变区.第4外显子Cys134Tyr突变类型为国内首次报告.     

腓骨肌萎缩症CMTX1型的间隙连接蛋白32基因突变检测

目的检测无基因重复的腓骨肌萎缩症患者间隙连接蛋白32(connexin32,Cx32)基因的突变情况。方法应用变性高效液相色谱(DHPLC)结合混合样品池法和脱氧核糖核酸(DNA)序列测定对1个临床可疑的X连锁显性遗传的腓骨肌萎缩症CMTX1型家系的先证者和15名家庭成员及60名家系外健康对照者进行Cx32基因外显子2的基因编码区突变检测,分3个片段扩增其基因编码区全长。结果先证者在片段2的DHPLC中发现杂合双峰,经DNA序列测定证实其Cx32外显子2发生Leu89Pro(266T→C)错义突变;家系内其他4例发病者和5名未发病者Cx32外显子2都有与先证者一致的DHPLC杂合双峰。60名健康对照者中未发现上述改变。结论Leu89Pro是该家系的致病性突变。该突变体的致病机制如何,有待于做进一步研究。     

Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.     

Hepatic Considerations in the Use of Antiepileptic Drugs

Summary: Virtually all of the major antiepileptic drugs (AEDs) can cause hepatotoxicity, although fatal hepatic reactions are rare. The mechanisms, incidences, and risk profiles for such reactions differ from drug to drug. With carbamazepine and phenytoin, hepatotoxicity may be due to drug hypersensitivity. Although the profiles of patients at risk have not been well-defined for these two antiepileptic drugs, it would appear from reports in the literature that older adolescents and adults are at higher risk than children of developing serious or fatal hepatotoxicity. Once hepatotoxicity develops, mortality rates are 10–38% with phenytoin and 25% for carbamazepine. The risk profile for valproate fatal hepatotoxicity has been more clearly defined. Those at primary risk of fatal hepatic dysfunction are children under the age of 2 years who are receiving multiple anticonvulsants and also have significant medical problems in addition to severe epilepsy. The risk is considerably lower for patients over the age of 2 years on valproate monotherapy. In contrast to the risk profile with other AEDs, adults receiving valproate as monotherapy have the lowest risk of hepatotoxicity. Fatal hepatic dysfunction coincident with valproate may be the result of aberrant drug metabolism. Concomitant use of AEDs that induce microsomal P450 enzymes (e.g., phenytoin and phenobarbital) may enhance the production of a toxic metabolite, and hence the greater risk of hepatotoxicity with polypharmacy.     

Vascular Malformations and Epilepsy: Clinical Considerations and Basic Mechanisms

Summary: Vascular malformations (VMs) are associated with epilepsy. The natural history of the various VMs, clinical presentation, and tendency to provoke epilepsy determine treatment strategies. Investigations have probed the mechanisms of epileptogenesis associated with these lesions. Electrophysiologic changes are associated with epileptogenic cortex adjacent to VMs. Putative pathophysiologic mechanisms of epileptogenesis include neuronal cell loss, glial proliferation and abnormal glial physiology, altered neurotransmitter levels, free radical formation, and aberrant second messenger physiology.     

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.     

Carbamazepine Efficacy and Utilization in Children

Summary: Carbamazepine is effective for preventing partial and generalized tonic-clonic seizures in children. Although absence epilepsies are more common in children than adults, an estimated 80% of children with epilepsy have seizure types or epilepsies that are potentially responsive to carbamazepine. The differential diagnosis of ictal staring is an especially important issue in children because absence and atypical absence seizures are more prevalent in children than adults. Age-related pharmacokinetic differences and drug interactions are major considerations in children. On average, children have higher clearance rates of carbamazepine, shorter half-lives, and higher ratios of carbamazepine-10, 11-epoxide to carbamazepine than adults. In addition, children with severe epilepsy are more likely to require multiple-drug therapy, which can lead to complex drug interactions. When carbamazepine is administered along with valproate, drug protein binding interactions can cause intermittent side effects.     

Neonatal Seizures: Problems in Diagnosis and Classification

Summary: The clinical identification of neonatal seizures is critical for the recognition of brain dysfunction; however, diagnosis is often difficult because of the poorly organized and varied nature of these behaviors. Current classification systems are limited in their ability to communicate motor, autonomic, and electroencephalo-graphic features of seizures precisely and to provide a basis for uniform effective diagnosis, therapy, and determination of prognosis. Recent investigations of neonates, utilizing bedside electroencephalographic/polygraphic/ video monitoring techniques, have provided the basis for improved diagnosis and classification of seizures in the newborn. These studies have demonstrated that not all clinical phenomena currently considered to be seizures require electrocortical epileptiform activity for their initiation or elaboration. In addition, the specific clinical character of the phenomena considered to be seizures, the clinical state of the infant, and the character of the EEG indicate the probable pathophysiological mechanisms involved and suggest probable etiologies, prognosis, and therapy. Similarities between animal models that demonstrate reflex physiology and neonates with motor automatisms and tonic posturing suggest that these clinical behaviors may not be epileptic in origin but, rather, primitive movements of progression and posture mediated by brainstem mechanisms. Although not all clinical behaviors currently considered to be neonatal seizures may have similar pathophysiological mechanisms, they are clinically significant because they all indicate brain dysfunction.     

Valproate Monotherapy in the Management of Generalized and Partial Seizures

Summary: For decades, therapeutic tradition has promoted the concept of polypharmacy in the management of epilepsy. In recent years, however, studies have shown that, for most patients, monotherapy can provide comparable or better seizure control than administration of multiple anticonvulsants, while diminishing the potential for adverse reactions, drug interactions, and poor compliance. Valproate is an important monotherapeutic agent that is highly effective in the control of idiopathic primary and secondarily generalized epilepsies, and partial seizures that do not generalize. Comparative studies have found that valproate is at least as effective as phenytoin and carbamazepine in the treatment of generalized and partial seizures. Given the similar efficacy, other factors such as pharmacokinetics and side effects may therefore determine anticonvulsant selection for monotherapy.     

Un nouveau cadre conceptuel de travail pour la psychiatrie

In an attempt to place psychiatric thinking and the training of future psychiatrists more centrally into the context of modern biology, the author outlines the beginnings of a new intellectual framework for psychiatry that derives from current biological thinking about the relationship of mind to brain. The purpose of this framework is twofold. First, it is designed to emphasize that the professional requirements for future psychiatrists will demand a greater knowledge of the structure and functioning of the brain than is currently available in most training programs. Second, it is designed to illustrate that the unique domain which psychiatry occupies within academic medicine, the analysis of the interaction between social and biological determinants of behavior, can best be studied by also having a full understanding of the biological components of behavior.