自由基在大鼠全脑缺血再灌流损伤中作用机理及保精增智液的保护作用

本文采用大鼠４血管关闭方法制作了全脑血再灌流模型。于再灌流后２４ｈ取双侧海马，分别采用Ｐｒｏｇａｌｌｏｌ－ＮＢＴ和改良的ＴＢＡ法测定了ＳＯＤ活性和ＬＰＯ含量。结果ＳＯＤ明显低于对照组而ＬＰＯ明显高于对照组（Ｐ＜０．０１）。同时观察了一种新的中药方剂—保精增智液对自由基的拮抗作用，实验证明该药造模后给药效果不明显（Ｐ＞０．０５），造模前给药可使ＬＰＯ下降及ＳＯＤ上升，与对照组比较差异显著（Ｐ＜０．０１）。证明该药对全脑缺血再灌流损伤引起的自由基升高有保护作用。     

自由基在大鼠全脑缺血再灌流损伤中作用机理及保精增智…

本文采用大鼠４血管关闭方法制作了全脑血再灌流模型，于再灌流后２４ｈ取双侧海马，分别采用Ｐｒｏｇａｌｌｏｌ－ＮＢＴ和改良的ＴＢＡ法测定了ＳＯＤ活性和ＬＰＯ含量，结果ＳＯＤ明显低于对照组而ＬＰＯ明显高于对照组（Ｐ〈０．０１）。同时观察了一种亲的中药方剂－保精增智液对自由基的拮抗作用，实验证明该药造模后给药效果不明显（Ｐ〉０．０５），造模前给药可使ＬＰＯ下降及ＳＯＤ上升，与对照组比较差异显著（Ｐ〈０．０     

帕金森病血抗氧化酶活性的研究

本文报道６７例帕金森病（ＰＤ）患者血超氧化物歧化酶（ＳＯＤ）．谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ），过氧化氢酶（ＣＡＴ）活性及脂质过氧化物（ＬＰＯ）量的测定结果。ＰＤ病人ＳＯＤ和ＧＳＨ－Ｐｘ活性高于正常对照组，但ＳＯＤ，ＧＳＨ－Ｐｘ和ＣＡＴ的活性及ＬＰＯ量与病程长短无明显关系，也与是否服用美多巴无关。研究结果提示，抗氧化酶活性的改变可能与ＰＤ病因有关。     

大鼠全脑缺血再灌流后4个脑区的谷氨酸,门冬氨酸,甘氨酸…

应用高效液相色谱仪，紫外分光光度检测器监测，测定大鼠全脑缺血再灌流后６ｈ￣７ｄ的海马、纹状体、丘脑和新皮层组织匀浆中谷氨酸（Ｇｌｕ）、门冬氨酸（Ａｓｐ）、甘氨酸（Ｇｌｙ）和ｒ－氨基丁酸（ＧＡＢＡ）含量变化。结果显示在海马和丘脑Ｇｌｕ含量于再灌流后６ｈ￣３ｄ下降（Ｐ〈０．０５和０．０１），ＧＡＢＡ含量升高（Ｐ〈０．０５和０．０１），在纹状体和新皮层除ＧＡＢＡ外，分别于６ｈ￣５ｄ均有不同呈度的升高。比     

大鼠脑缺血再灌注海马区血小板活化因子和过氧化脂质的改变及药物影响

目的观察缺血性大鼠脑海马区血小板活化因子（ＰＡＦ）和过氧化脂质（ＬＰＯ）含量的改变及兆科蝮蛇抗栓酶的影响。方法用４ＶＯ大鼠脑缺血模型，用放免分析法和ＴＢＡ法测定ＰＡＦ及ＬＰＯ含量。结果缺血２０ｍｉｎ再灌注６０ｍｉｎ脑海马中ＰＡＦ及ＬＰＯ含量明显高于正常对照组（Ｐ＜０．０１），但造模前用兆科蝮蛇抗栓酶预处理动物，能够显著抑制缺血再灌注脑海马区ＰＡＦ及ＬＰＯ含量的升高。结论ＰＡＦ参与了脑缺血再灌注损伤，与ＬＰＯ生成密切相关，兆科蝮蛇抗栓酶对脑缺血再灌注损伤有保护作用。     

实验性迟发性脑血管痉挛时痉挛动脉的自由基代谢

为探讨蛛网膜下腔出血（ＳＡＨ）后迟发性脑血管痉挛（ＤＣＶＳ）时痉挛动脉的自由基代谢变化。通过了对ＤＣＶＳ时痉挛动脉的自由基含量、自由基清除酶超氧化物岐化酶（Ｃｕ－ＺｎＳＯＤ）与过氧化氢酶（Ｃａｔ）活性以及自由基代谢产物脂质过氧化物（ＬＰＯ）含量的测定。结果显示：（１）痉挛动脉的自由基含量比对照组明显升高（Ｐ＜０．０１）；（２）Ｃｕ－ＺｎＳＯＤ活性明显降低（Ｐ＜０．０５），Ｃａｔ活性明显升高（Ｐ＜０．０１）；（３）ＬＰＯ含量明显升高（Ｐ＜０．０１）。本实验结果证实ＳＡＨ后ＤＣＶＳ时痉挛动脉存在自由基的代谢紊乱，自由基介导的病理作用可能在ＤＣＶＳ发病机理中起重要作用。     

大鼠全脑缺血再灌后几个脑区在不同时间的LPO、SOD、GSH－Px含量变化

本文采用四血管阻断方法制成Ｗｉｓｔａｒ大鼠全脑缺血１０分钟再灌流模型。分别于再灌流７天内对新皮层、海马、丘脑、纹状体和小脑等五个脑区的ＬＰＯ、ＳＯＤ、ＧＳＨ—Ｐｘ含量进行测定。ＬＰＯ在各脑区于再灌流后开始升高，２４小时达高峰，第５天基本降至对照组水平。ＳＯＤ在６小时内迅速降至最低水平，然后逐渐回升，但在第７天时仍低于对照水平。ＧＳＨ—Ｐｘ在各脑区均呈双时相改变，先降后升，然后再逐渐下降，在第７天时略低于对照组。经相关分析，ＬＰＯ与ＳＯＤ呈显著负相关，ＬＰＯ与ＧＳＨ—Ｐｘ无相关关系。本文还对自由基在脑缺血后迟发性神经元坏死中的作用机制进行了讨论。     

神经症患者超氧化物歧化酶、谷胱甘肽超氧化物酶及脂质超氧化物含量的变化

为研究氧自由基与神经症之间的关系，分别采用邻苯三酚自氧化法、二硫对硝基苯甲酸直接法、硫代巴比妥酸比色法，测定了８７例神经症和５５名健康人超氧化物歧化酶（ＳＯＤ）、谷胱甘肽超氧化物酶（ＧＳＨ－Ｐｘ）和脂质超氧化物（ＬＰＯ）含量。结果显示，神经症组ＳＯＤ与ＧＳＨ－Ｐｘ两种酶含量均低于对照组，神经症组治疗前低于治疗后；ＬＰＯ为治疗前高于治疗后，差异均有显著性。从单胺类的代谢与生成氧自由基的生化联系以及机体内ＳＯＤ、ＧＳＨ－Ｐｘ、ＬＰＯ之间的相互关系上对结果进行了分析，提示体内单胺类物质代谢过程中产生的氧自由基在神经症的病理过程中可能发挥一定的作用。     

出血性卒中患者脑脊液微量元素和抗氧化酶含量的研究

本文测定３６例脑出血、３１例ＳＡＨ患者的脑脊液微量元素和抗氧化酶含量的变化，结果发现：脑出血和ＳＡＨ的脑脊液锌、硒、铬、铁、镁含量，ＧＳＨ－Ｐｘ活性和Ｇ／Ｍ比值明显低于对照组（Ｐ＜０．０５或Ｐ＜０．０１），铜、ＭＤＡ含量及ＳＯＤ活性明显高于对照组（Ｐ＜０．０５或Ｐ＜０．０１）。提示：微量元素和抗氧化酶与出血性卒中有密切关系。     

大鼠脑缺血再灌流时检测血中脑细胞胞浆酶的意义

研究大鼠脑缺血灌流时脑细胞浆酶含量的变化及其临床意义。方法：采用全自动生化分析仪检测血清肌酸激酶（ＣＫ）、肌酸激酶脑型同工酶（ＣＫ－ＢＢ）、乳酸脱氢酶（ＬＤＨ）以及天门冬氨酸氨基转换酶（ＡＳＴ）的含量。结果：脑缺血２０ｍｉｎ,血中ＣＫ、ＣＫ－ＢＢ和ＬＤＨ的含量明显高于假手术组（Ｐ〈０．０５或Ｐ〈０．０１）。脑缺血再灌注后血中ＣＫ、ＣＫ－ＢＢ、ＬＤＨ和ＡＳＴ的含量明显高于假手术组和脑缺血组。结论：脑     

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.     

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.     

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.     

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.     

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.