黄芩甙治疗实验性自身免疫性脑脊髓炎的实验研究

目的研究黄芩甙治疗实验性自身免疫性脑脊髓炎(EAE)的可能性及有效性。方法应用髓鞘脂质蛋白(PLP)139-151免疫SJL/J小鼠诱发慢性复发-缓解型EAE模型,研究黄芩甙对PLP139-151诱导的小鼠淋巴结细胞增殖反应及干扰素-γ(IFN-γ)、白介素-4(IL-4)分泌的作用,使用流式细胞技术检测黄芩甙对EAE小鼠淋巴结细胞CCR5表达的影响;通过神经功能评分观察黄芩甙治疗EAE的有效性。结果黄芩甙可抑制PLP139-151诱导的淋巴结细胞增殖反应及IFN-γ的分泌,提高IL-4的分泌(P<0.001),有效降低EAE小鼠淋巴结细胞CCR5的表达;显著改善EAE小鼠神经功能评分(P<0.01),使发病时间延迟(P<0.01)。EAE小鼠发病数和死亡数较对照组减少,但差异并无统计学意义(P>0.05)。结论黄芩甙可有效治疗EAE,为黄芩甙用于临床多发性硬化的治疗提供了实验依据。     

小胶质细胞在PLP_(139-151)诱导SJL小鼠EAE模型中的作用研究

目的观察髓鞘蛋白脂质蛋白139-151(proteolipid protein,PLP_(139-151))诱导SJL小鼠构建的复发缓解型的实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)模型复发期脑内小胶质细胞的病理改变。方法应用100μg、150μg PLP_(139-151)多肽片段免疫SJL小鼠构建复发缓解型EAE模型(分别简称为100μg PLP组、150μg PLP组),另设健康对照组(对照组;采用与实验组等体积溶媒处理),观察35 d。观察两组EAE小鼠的发病情况及神经功能残疾进展评分差异,选择发病快、神经功能残疾进展评分高者(计为EAE组)观察复发期小胶质细胞活化情况。EAE组于复发期疾病高峰时,对照组于相同时间点,取小鼠大脑皮层组织,应用免疫组织化学(immunohistochemical,IHC)染色及免疫荧光(immunofluorescence,IF)染色比较两组小胶质细胞的活化情况。结果 150μg PLP组小鼠在两个发病高峰(分别为免疫第13、28天)均早于100μg PLP组(分别为免疫第15天、31天),神经功能评分第2次发病高峰高于100μg PLP组(3.00±0.79 vs. 1.75±0.90,t=2.33,P0.05),第1次发病高峰与100μg PLP组差异无统计学意义(P0.05),故选择150μg PLP组(计作EAE组)观察复发期(免疫后第28天)小胶质细胞活性。与对照组相比,EAE组小鼠复发期大脑皮层中小胶质细胞的活化明显增多,组织染色上表现为Iba-1表达增高,细胞体积增大,细胞突起增多。结论 150μg PLP_(139-151)多肽片段免疫SJL小鼠构建的复发缓解型EAE模型复发期小鼠大脑皮层小胶质细胞明显活化。     

PLP不同肽段诱导EAE模型的对比研究

目的建立不仅与多发性硬化(multiple sclerosis，MS)临床表现、病理特征接近而且病程相似的较为理想的复发一缓解型实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis，EAE)模型。方法应用髓鞘蛋白脂质蛋白(proteolipid potein，PLP)多肽的两种免疫优势表位肽段PLP139-151和PLP178-191免疫雌性SJL／J小鼠，制作复发缓解型EAE(relapse remitting experimental autoimmune encephalomyelitis，RR—EAE)模型，观察其体重及神经功能评分的变化，应用HE、Luxol fas tblue髓鞘染色等方法观察模型的组织形态学改变。结果两种PLP肽段免疫的小鼠发病均具有缓解一复发的特点，出现明显的神经系统体征；小鼠发病时脑和脊髓组织显示明显的血管鞘形成、卫星现象和炎性细胞浸润以及脱髓鞘改变。结论PLP两种肽段均可诱发RR-EAE模型，这与临床MS的缓解一复发病程更相似，更能表现MS的临床特点，是研究MS的较为理想的动物模型。     

MK-801对EAE动物模型轴索损伤的保护作用研究

目的通过建立实验性自身免疫性脑脊髓炎(EAE)动物模型,对EAE的发病机制和轴索损伤进行研究,并进行药物干预,寻找新的治疗方法。方法选用髓鞘蛋白脂蛋白(PLP139-151)多肽作为抗原免疫雌性SJL/J小鼠,诱发EAE小鼠模型,应用MK-801(0.30mg/kg)进行干预。发病后取脑、脊髓组织切片,进行免疫组织化学检查。结果模型组23(23/30)只小鼠发病,发病率为76.7%,平均发病时间为19±2.58天,平均神经功能评分为2.14±0.69分。药物(MK-801)治疗组16(16/30)只小鼠发病,发病率为53.3%,平均发病时间为21±1.25天(P<0.05),平均神经功能评分为1.08±0.42分(P<0.02);病理显示药物干预后病灶减少,病变减轻。结论PLP多肽诱发SJL/J小鼠的EAE动物模型的病理改变主要累及脊髓。谷氨酸的兴奋性毒性参与MS发病和轴索损伤,应用NMDA受体拮抗剂MK-801可以减少神经功能缺失,降低发病率。     

自身抗原冲击的树突状细胞抑制实验性自身免疫性脑脊髓炎具有抗原特异性(简报)

树突状细胞(dendritic cells，DC)不仅有免疫刺激作用．而且能通过诱导中枢和外周耐受而调节免疫反应。近年发现，在诱发自身免疫性疾病动物模型如实验性自身免疫性脑脊髓炎(EAE)之前，皮下注射致病抗原碱性髓鞘蛋白68-86(MBP68-86)体外冲击的DC，对该抗原诱导的EAE模型有明显抑制作用。此研究采用皮下注射3种不同的致脑炎肽MBP68-86、蛋白脂质蛋白139-151(PLP139-151)和髓鞘少突胶质细胞糖蛋白肽(MOG35-55)体外冲击DC，对EAE进行研究。     

实验性自身免疫性脑脊髓炎动物模型早期轴索损伤

目的 研究实验性自身免疫性脑脊髓炎(EAE)动物模型发病早期的轴索损伤.方法 采用髓鞘蛋白脂蛋白(PLP139-151)多肽作为抗原诱发EAE小鼠模型.小鼠经免疫后每天进行神经功能评分及称体质量,于发病后剥离脑及脊髓组织进行病理学研究.结果 7只(23.3%)小鼠于免疫后15～22 d内发病,平均免疫后发病时间为(19.00±2.58)d,平均神经功能评分为(2.14±0.69)分.免疫前小鼠平均体质量[(21.85±0.94)g]与发病后体质量[(23.24±1.55)g]比较差异无统计学意义.HE染色可见发病小鼠软脊膜下脊髓组织炎性细胞浸润明显,以小血管周围为主的血管袖套形成.病变累及脊髓多见,且较大脑病变重.LFB染色可见炎细胞浸润处髓鞘有不同程度脱失,同时Bodian银染可见轴索肿胀、横断.免疫组织化学染色可见髓鞘碱性蛋白着色的相同区域淀粉样前体蛋白浓染,而星形胶质细胞GFAP染色增生不明显.结论 PLP多肽诱发SJL/J小鼠的EAE模型临床症状较轻,病变主要累及脊髓,而在大脑未发现与MS类似的典型病灶.在EAE发病早期,髓鞘还未明显脱失时即可见轴索损伤,且早期轴索损伤与临床症状并不平行.     

实验性变态反应性脑脊髓炎的病理学研究

目的用豚鼠脊髓匀浆诱发实验性变态反应性脑脊髓炎（EAE）大鼠模型。方法应用豚鼠脊髓匀浆加完全弗（氏）佐剂和百日咳杆菌免疫Wistar大鼠。结果免疫后8～14d大鼠发病，发病率为67％，病理学证实发病大鼠脑和脊髓审具有典型的脱髓鞘改变和炎性细胞浸润。结论以豚鼠脊髓匀浆为抗原免疫Wistar大鼠可诱发EAE，具有发病率较高，费用低廉，模型稳定的特点，可作为研究多发性硬化的动物模型。     

日本血吸虫虫卵抗原对实验性脑脊髓炎的干预研究

目的利用日本血吸虫虫卵抗原(SEA)来干预实验性自身免疫性脑脊髓炎(EAE)小鼠模型,试图探讨寄生虫感染与EAE的关系。方法利用血吸虫虫卵抗原干预EAE小鼠,观察行为学和病理改变。同时取不同抗原刺激的淋巴结细胞培养,ELISA法测定上清IL-4、IFN-γ的含量。结果用SEA不同时间段干预EAE,发现可以减轻EAE的发病程度,但在延缓和阻止发病方面作用不明显,并在行为学和病理学上得到证实。而用SEA和PLP178-191体外刺激联合免疫后小鼠的淋巴结细胞,发现SEA刺激后可以升高IL-4,降低IFN-γ,而PLP178-191刺激则相反。在单用PLP178-191免疫和联合免疫相比较中,发现PLP178-191体外再刺激后联合免疫组细胞分泌IFN-γ降低,IL-4升高。结论SEA可以减轻EAE的发病程度。细胞因子在寄生虫感染影响EAE的发病中起了重要的作用,调节Th1/Th2平衡,纠正体内Th1偏移是寄生虫抗原能够调节EAE发病的原因之一。     

实验性自身免疫性脑脊髓炎小鼠的磁共振研究

目的研究动物模型实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)小 鼠中枢神经系统的MR表现。方法使用PLP139-151免疫接种雌性SJL／J小鼠诱导EAE。分别取复发期和缓解期 的EAE小鼠行脑和脊髓常规MR及Gd—DTPA增强MR扫描,并做组织病理学检查。结果PLP139-151能较好的诱 导出慢性复发-缓解型EAE模型,Gd-DTPA增强MR检查能充分显示血脑屏障的破坏,反映脑和脊髓的病灶,而且 显示的病灶相对信号强度复发期明显高于缓解期,在病灶处均可见炎症细胞浸润,髓鞘脱失,病灶周围或远离病灶 处炎症反应轻微。结论Gd—DTPA增强MR检查能准确反映血脑屏障的破坏,病变累及部位及病变程度,为今后使 用药物干预EAE判断疗效、指导进行较准确的病变部位取材时提供了一种更为客观的手段。     

大鼠实验性变态反应性脑脊髓炎模型研究

目的 用豚鼠脊髓匀浆诱发实验性变态反应性脑脊髓炎（EAE）大鼠模型。方法 应用豚鼠脊髓匀浆加完全弗氏佐剂和百日咳杆菌免疫Wistar大鼠。结果 免疫后8-14d大鼠发病，发病率为67％，光镜下病理学证实发病大鼠脑和脊髓内具有典型的脱髓鞘改变和炎性细胞浸润。电镜下也可见到髓鞘结构破坏和神经元轻微改变。结论 以豚鼠脊髓匀浆为抗原免疫Wist—ar大鼠可诱发EAE，具有发病率较高、费用低廉、模型稳定的特点，可以作为研究多发性硬化的动物模型。     

Diagnostic Difficulties and Treatment Implications

Summary: Differentiation between types of epileptic seizures has been aided in recent years by the introduction of intensive neurodiagnostic techniques and the development of increasingly detailed classification systems. Paradoxically, these developments have not simplified the task of matching the appropriate antiepileptic drug to a particular seizure type. It is reasonable to assume that anticonvulsant drugs will have different effects on different types of seizures, but faulty, circular reasoning can enter the picture if one also assumes that responses of seizures to different drugs signify different seizure types. There are several examples of differential diagnoses that can fall prey to this problem, including the diagnosis between partial seizures with secondary generalization and generalized tonic-clonic seizures, and the diagnosis between complex partial seizures and absence seizures with automatisms, among others. Considerations of etiology in future classification systems can further complicate the problem: should one then choose an anticonvulsant drug on the basis of individual seizure type or on the basis of the type of epilepsy? Ramifications of this issue extend even to the drug approval process. Official sanction is not given for use of a drug for a seizure type not included in the original efficacy studies, even if later scientific evidence shows that seizure type to be related to a type that is included. New trials must be undertaken. These problems arise from how we choose to classify seizures.     

Cognitive Dysfunction Associated with Antiepileptic Drug Therapy

Summary: Epilepsy is frequently associated with cognitive dysfunction. However, the reasons for this correlation are unclear. Possible influential factors include patient age; duration, frequency, etiology, and type of seizures; hereditary factors; psychosocial issues; and antiepileptic drug (AED) therapy. Whereas many of these factors are beyond the physician's control, AED therapy is one element that can be addressed in treatment decisions by recognizing the potential cognitive effects of particular AEDs. For example, phenobarbital impairs memory and concentration; phenytoin affects attention, problem solving ability, and performance of visuomotor tasks. In contrast, carbamazepine may affect concentration, while valproate would appear to have minimal effects on cognition. Moreover, cognitive effects of AEDs are amplified with coadministration of multiple anticonvulsants (polytherapy). A review of studies on the cognitive effects of monotherapy with AEDs, as opposed to those of polytherapy, provides evidence that drug-related cognitive dysfunction can be reversed if patients are switched to a simpler therapeutic regimen. Future research should be directed toward developing reliable measures for assessing and monitoring cognition, and understanding the particular cognitive side effects of each AED. Physicians also need to revise their opinions about which side effects are "tolerable" for epileptic patients.     

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.     

Carbamazepine Efficacy in Adults With Partial and Generalized Tonic-Clonic Seizures

Summary: Carbamazepine and phenytoin are drugs of choice in initial monotherapy for adult partial and secondarily generalized tonic-clonic seizures. These designations reflect the results of the Veterans Administration Epilepsy Cooperative Study Group of 1985. An earlier comparative study of carbamazepine and phenytoin by Ramsay and associates found both drugs equally effective in controlling new-onset seizures. Among the advantages of carbamazepine is that it causes relatively few cognitive and dysmorphic side effects. Its disadvantages are its unavailability in parenteral formulation and its metabolic autoinduction. The latter must be compensated for by planned dosage increases to maintain therapeutic plasma steady-state levels during the first 2 or 3 months of treatment. Carbamazepine is judged a drug of choice in the treatment of these secondarily generalized tonic-clonic seizures, and the drug of choice in children, adolescents, and women susceptible to the dysmorphic side effects associated with other anticonvulsant agents.     

Etiologic and Preventive Aspects of Epilepsy in the Child–Bridging the Gap Between Laboratory and Clinic

Summary: Four broad categories of basic phenomena are pertinent to developing ways to prevent epilepsy. These include mechanisms of epileptogenesis, ictal initiation and temporary entrainment by the seizure discharge of normally functioning brain, seizure propagation, and control mechanisms that function both to restrain the cascade of epileptic events culminating in a seizure and to arrest the epileptic event and restore the interictal state. In newborns and children, hypoxia-ischemia is a major factor leading to epileptogenesis, and several schemes are proposed to classify, quantify, and prevent hypoxic-ischemic encephalopathy. Control mechanisms must be better understood in order to develop prophylactic recommendations for epilepsy, and an experimental model of "kindling antagonism" may increase our understanding of these. Programs of prevention of seizures in children will evolve only if basic researchers and clinicians work productively together to develop an adequate understanding of factors important in epileptogenesis and antiepileptogenic control mechanisms.     

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.     

Predisposing and Causative Factors in Childhood Epilepsy

Summary: We review information from large studies of defined populations, examining the role of known factors and especially of prenatal and perinatal factors in contributing to nonfebrile seizure disorders of early childhood. We depend especially, but not exclusively, on the recently completed analyses from the Collaborative Perinatal Project of the National Institute of Neurological and Communicative Disorders and Stroke, the NCPP. About 4% of children in the NCPP who had at least one non-febrile nonsymptomatic seizure by the age of 7 years had a previous seizure during acute neurologic illness, such as meningitis or during the acute illness after trauma. Many such seizures should potentially be preventable. Of children with seizures, 10% had had a neonatal seizure and 13% had had a febrile seizure. Among the hundreds of prenatal and perinatal factors explored as predictors of childhood seizure disorders, the principal predictors identified were congenital malformations of the fetus, cerebral and noncerebral; family history of certain neurologic disorders; and neonatal seizures. In agreement with the British National Child Development Study, labor and delivery factors in the NCPP appeared to contribute very little to childhood seizure disorders. Maldevelopment, rather than damage at birth to an initially intact nervous system, appeared to be the more common mechanism. Most seizure disorders of early childhood remained unexplained by the large set of prenatal and perinatal characteristics examined.     

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.     

Anticonvulsant Drugs and Cognitive Function: A Review of the Literature

Summary: Alterations of cognitive function are separate from disturbances of behavior seen in association with epilepsy. The nature of the cognitive disability may to a certain extent depend on the seizure type. Partial seizures, mainly derived from a temporal lobe focus, impair memory tasks, while generalized seizures seem to have more effect on attentional abilities. A number of studies, reviewed in this paper, suggest that anticonvulsant drugs further impair cognitive function. Maximal impairments are seen in patients receiving polytherapy: rationalization of polytherapy improves cognitive abilities. Studies in children and adults have allowed differentiation of the effects of various commonly used antiepileptic agents. Maximal cognitive deficits are seen with. phenytoin, while phenobarbital and sodium valproate induce moderate disturbances, and carbamazepine seems relatively free from such toxicity. Further research is needed on the interrelationship between types of seizure disorders, types of anticonvulsant medications, and cognitive function.