重症肌无力免疫营养治疗进展

<正>重症肌无力(myasthenia gravis,MG)是一种神经、肌肉接头部位传导障碍的自身免疫性疾病。胸腺在MG中起重要作用,80%以上的患者伴发胸腺组织增生;15%～20%患者伴发胸腺瘤。因胸腺是免疫系统维持自身内环境稳定以及自身免疫耐受的主要器官,也是T细胞发育、成熟的主要场所,所以胸腺病变可引起T细胞异常,Sun等~([1])发现临床症状较重的MG患者外周血调节性T细胞明显降低,而胸腺切     

天然调节性T细胞特性及以其为靶点治疗重症肌无力的研究进展

重症肌无力(MG)是一种细胞依赖性自身免疫性疾病,胸腺起源的CD4+T细胞的大量激活是MG发生的一个重要原因。天然调节性T细胞(nTreg)是一个具有独特免疫调节功能的CD4+调节性T细胞亚群,在自身免疫中发挥着重要作用。最近的研究发现nTreg与MG关系密切,针对nTreg来治疗MG是一种新的手段。本文就nTreg的特性及针对其治疗MG取得的成果做一综述。     

重症肌无力发病相关基因多态性的研究进展

重症肌无力(MG)是一种神经肌肉接头传递功能障碍的自身免疫性疾病,其发病免疫机制尚未完全阐明,神经肌肉接头处其他抗体、抗原特异性T细胞、细胞因子、调节性T细胞等多种因素都与MG的发病机制有关,其中遗传因素在MG的发病中具有十分重要的作用.基因芯片技术可用于对疾病的相关基因进行筛选,并对疾病的分类、预后、治疗效果提供有用的信息.MG的易患基因及基因多态性的复杂性,目前在研究策略上还有待于进一步探索,现就近年来MG遗传学研究的进展综述如下.     

树突状细胞与重症肌无力免疫耐受治疗的研究进展

重症肌无力(MG)是累及神经-肌肉接头处突触后膜上乙酰胆碱受体(AchR)的自身免疫性疾病,同时亦是迄今为止抗原抗体最为明确的自身免疫性疾病,患者细胞和体液免疫应答均存在异常,但MG确切的发病机制仍不完全清楚,它可能是一种由多基因调控、多种机制参与的复杂性疾病[1].     

胸腺与重症肌无力发病机制的研究进展

重症肌无力(MG)是一种主要累及神经-肌肉接头突触后膜乙酰胆碱受体的获得性自身免疫性疾病。临床上主要表现为部分或全身骨骼肌无力和极易疲劳,活动后加重,经休息和胆碱酯酶抑制剂治疗后症状减轻。大多数MG患者可见胸腺病理改变。研究表明,胸腺病毒感染及慢性炎症刺激、异常免疫激活、胸腺中枢耐受性破坏及免疫调节失衡参与了MG的发生和发展过程。     

T细胞免疫在胸腺瘤与重症肌无力发病中的研究进展

重症肌无力(myasthenia gravis,MG)是主要累及神经肌肉接头(neuromuscular junction,NMJ)处突触后膜上乙酰胆碱受体(acetylcholine receptor,AchR)致神经肌肉突触传递障碍的一种自身免疫性疾病[1]。T细胞免疫在重症肌无力的发病中扮演着重要的角色,胸腺系中枢免疫器官,是T细胞发育、成熟的主要场所,也是免疫系统维持自身内环境稳     

B细胞免疫调控在重症肌无力中的作用

B细胞是重症肌无力(MG)发病的直接参与者,其免疫调控对疾病发生发展起重要作用。B细胞是一种抗原提呈细胞,与其他的免疫细胞互相作用产生自身抗体,除此之外,还具有其他一些特殊功能,如通过分泌细胞因子调控树突状细胞(DC)及T细胞功能,激活T细胞的免疫调控等。调节性B细胞通过分泌调节性细胞因子,细胞间接触等发挥免疫抑制功能。鉴于B细胞及其他免疫细胞在MG发病中的作用,新的针对B细胞的治疗策略已引起广泛关注。     

白细胞介素与重症肌无力

重症肌无力(MG)是选择性侵犯神经肌肉接头处突触后膜上乙酰胆碱受体(AchR)的自身免疫性疾病。乙酰胆碱受体抗体(AchRab)介导的体液免疫和T细胞介导细胞免疫是其主要发病机制,但其免疫紊乱的具体环节尚不清楚。自细胞介素(IL)作为细胞因子的重要组成部分,其活性的改变可反映体内免疫功能紊乱的状况;可直接影响B细胞的数量和功能,进而影响AchRab的产生。本文着重介绍相关IL在MG中的作用及有关机制。     

重症肌无力免疫学发病机制研究进展

重症肌无力(MG)是典型的由抗体介导、T细胞依赖、补体参与的器官特异性自身免疫性疾病,其发病的关键在于机体自我耐受的打破,产生针对自身抗原乙酰胆碱受体的异常免疫应答。胸腺、T细胞、补体及补体调节因子、B细胞均在MG发病中发挥一定作用,现分别就其在MG发病机制中的作用研究进行综述。     

重症肌无力发病机制的研究进展

重症肌无力 (myastheniagravis,MG)是一种神经肌肉接头 (neuromuscularjunction,NMJ)传递功能障碍的自身免疫性疾病,其发病机制尚未完全阐明。传统观点认为MG的发病与乙酰胆碱受体自身抗体(AChR Ab)介导的体液免疫密切相关,但最近发现NMJ处其他抗体、抗原特异性T细胞、细胞因子、调节性T细胞、遗传因素等在MG的发病中也扮演了重要的角色。一、体液免疫临床上发现大约 80%的MG患者血清中能检测到AChR Ab,称为血清阳性重症肌无力 (seropositivemyastheniagravis,SPMG),而另外 20%的MG患者体内不能检测到AChR Ab,即所谓血清…     

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.     

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.     

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.     

Treatment Considerations in Anticonvulsant Monotherapy

Summary: The long-standing practice of polypharmacy in treating epilepsy is giving way to use of monotherapy. Monotherapy can improve seizure control as well as reduce the risk of serious idiosyncratic reactions, dose-related side effects, and complex drug interactions. Monotherapy also offers improved compliance and cost-effectiveness. The basis of monotherapy is accurate diagnosis and assessment of the patient's seizure type(s), followed by selection of a single appropriate anticonvulsant drug. Many patients currently treated with multiple anticonvulsants can be successfully converted to monotherapy with a carefully monitored program in which troublesome and redundant drugs are gradually withdrawn from the therapeutic regimen.     

Effects of NMD A- and AMPA-Receptor Antagonists on Different Forms of Epileptiform Activity in Rat Temporal Cortex Slices

Summary: Lowering extracellular magnesium induces different patterns of epileptiform activity in rat hippocampus and entorhinal cortex. Short recurrent epileptiform discharges in the hippocampus are stable over time, whereas seizurelike events (SLEs) in the entorhinal cortex, the subiculum, and the neighboring neocortex develop into late recurrent discharges which are not blocked by clinically employed antiepileptic drugs. We tested the sensitivity of the different epileptiform discharge patterns to. /V-methyl-D-aspartate (NMDA)- and non-NMDA-receptor antagonists. As NMDA-receptor antagonist we used dextrorphan, ket-amine, and 2-aminophosphonovalerate (2APV); as α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)-receptor antagonist we employed the quinoxaline derivative glutamate 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). The findings show that the different patterns of epileptiform activity, including the late recurrent discharges, are sensitive to all NMDA-receptor antagonists. However, when dextrorphan was employed to suppress seizure-like events, later recurrent discharges did not develop during the remaining time course of the experiment. CNQX reversibly suppressed recurrent discharges in the hippocampus and SLEs in the entorhinal cortex. However, late recurrent discharges become insensitive to CNQX, even at a high concentration of 60 μM m. This finding suggests a prominent role for NMDA receptors in the generation of late recurrent discharges.     

Dextromethorphan: Cellular Effects Reducing Neuronal Hyperactivity

Summary: Dextromethorphan is a dextrorotary morphinan without affinity for opioid receptors, commonly used as an antitussive medication. During the past 5 years, interest in the compound and its demethylated derivative, dextrorphan, has been revived because additional neuroprotective and an-tiepileptic properties were found in in vitro studies, animal experiments, and a few clinical cases. Both morphinans are able to inhibit N -methyl-D-aspartate (NMDA) receptor channels and voltage-operated calcium and sodium channels with different potencies. The inhibition of the NMDA receptor is believed to be the predominant mechanism of action responsible for the anticonvulsant and neuroprotective properties of the compounds.