肌萎缩侧索硬化症患者血浆和脑脊液谷氨酸含量变化的研究

目的 了解肌萎缩侧索硬化症(ALS)患者血浆、脑脊液谷氨酸浓度的改变,为治疗提供依据。方法应用毛细管电泳-激光诱导荧光检测器,测定ALS患者和对照组的血浆及脑脊液谷氨酸含量,比较两者的不同,并对不同病情ALS患者的谷氨酸浓度进行比较。结果 ALS患者血浆、脑脊液谷氨酸的浓度均较对照组明显升高(P<0.05)。不同病情患者间的谷氨酸浓度也有区别,谷氨酸水平升高程度与病情轻重相关。结论 ALS患者血浆和脑脊液的谷氨酸水平较正常高,脑脊液谷氨酸浓度比血浆浓度敏感,临床病情越重,谷氨酸浓度越高。     

利鲁唑降低肌萎缩侧索硬化症患者谷氨酸水平

目的　初步探讨利鲁唑对肌萎缩侧索硬化症 (amyotrophic lateral sclerosis,ALS)患者血浆谷氨酸的改变 ,为临床治疗提供依据。方法　应用毛细管电泳 -激光诱导荧光检测器 ,测定 ALS患者和对照组血浆及脑脊液(CSF)谷氨酸水平 ,以及部分 ALS患者服用利鲁唑后血浆谷氨酸水平 ,并进行统计分析。结果　 ALS患者血浆、CSF谷氨酸水平分别为 (75 .65± 2 0 .44)和 (8.1 1± 2 .71 )μmol/L,与对照组相比差异有显著性 (P <0 .0 5 )。ALS患者服用利鲁唑后 ,血浆谷氨酸的水平为 (66.1 9± 1 0 .2 7) μmol/L,与服药前比较差异有显著性 (P <0 .0 5 ) ,但仍高于对照组。结论　 ALS患者血浆和 CSF谷氨酸水平较正常为高。 ALS患者在口服利鲁唑后血浆谷氨酸水平有所下降 ,但仍高于正常水平。     

肌萎缩侧索硬化患者血浆TDP-43含量及与病程关系的研究

目的检测肌萎缩侧索硬化(ALS)患者与健康人血浆中TAR DNA结合蛋白43(TDP-43)水平,探讨血浆TDP-43浓度变化与ALS病程之间的关系。方法收集散发性ALS患者和健康人血浆,利用ELISA法测定血浆中TDP-43浓度,使用SPSS软件进行统计学分析。结果散发性ALS患者血浆中TDP-43浓度显著高于健康人,随着病程的进展,血浆中TDP-43浓度没有明显的变化。结论 TDP-43是散发ALS的一个重要生化指标,其在ALS患者血浆中含量增加,但与疾病病程无关。     

急性缺血性卒中患者谷氨酸的释放研究

目的谷氨酸释放所致神经元兴奋毒性损伤在局灶性脑缺血的发病展性缺血性卒中患者谷氨酸升高的时间和谷氨酸释放抑制剂及谷氨酸受体拮抗剂的治疗时间窗.方法本研究共纳入128例脑梗死病人.用高效液相色谱分析(HPLC)检测了病人和对照者的血浆和脑脊液(CSF)谷氨酸浓度,并同时评定了加拿大卒中标准(CSS)积分和脑梗死容积(CTV).结果病人的平均血浆和CSF谷氨酸浓度均显著高于对照组(P分别小于0.01和0.001).50例进展性卒中患者的平均血浆和CSF谷氨酸浓度均显著高于78例稳定性卒中组.CTV≥10cm3的卒中患者的CSF谷氨酸浓度显著高于CTV＜10 cm3患者,并且50例进展性卒中患者的CSF谷氨酸浓度与其CTV值显著相关(r=0.303,P＜0.05).结论本结果提示,急性脑缺血患者预防神经病学进展,谷氨酸拮抗剂的应用有较宽的治疗时间窗.CSF中的谷氨酸含量可作为判断缺血性卒中的进展和谷氨酸释放抑制剂的一个指标.     

Alzheimer’s病患者血浆和脑脊液胰岛素浓度变化的研究

目的探讨Alzheimer's病(AD)患者血浆和脑脊液胰岛素水平与疾病的关系。方法对23例AD患者和12例年龄相匹配的健康成人进行双份空腹血浆和脑脊液胰岛素浓度检测,确定是否胰岛素水平与痴呆严重性和载脂蛋白E-ε4(已知为AD的遗传性危险因素)纯合性相关。结果与健康成人相比。AD患者脑脊液胰岛素浓度降低,血浆胰岛素浓度升高,脑脊液与血浆胰岛素比例与健康对照者相比有很大差异,进展性AD患者更明显。结论非载脂蛋白E-ε4纯合性患者血浆胰岛素浓度增高,脑脊液与血浆胰岛素比例降低,载脂蛋白E-ε4纯合性的AD患者正常,血浆和脑脊液胰岛素浓度异常的AD患者存在明显的载脂蛋白E-ε4代谢异常。     

脑胶质瘤患者术后脑脊液谷氨酸与继发性癫痫发作的关系

目的研究脑脊液谷氨酸水平与脑胶质瘤患者术后继发性癫痫发作的相关性。方法收集190例脑胶质瘤患者外科手术后1个月内的脑脊液标本,根据患者术后是否有继发性癫痫发作将其分成为无癫痫发作组(n=117)和有癫痫发作组(n=73);使用高效液相层析法检测并比较2组患者脑脊液中谷氨酸的水平。结果 35%的胶质瘤患者术后仍有癫痫发作,其中96%的患者术前有癫痫发作。与胶质瘤术后继发癫痫发作风险相关的独立临床因素包括:术前有癫痫发作、年龄较轻、肿瘤位于颞叶和肿瘤中含少突胶质细胞成分。术后有癫痫发作的胶质瘤患者脑脊液中谷氨酸水平明显高于无癫痫发作组(P0.05)。Logistic回归分析发现:脑脊液中谷氨酸浓度的增加,年龄较轻、肿瘤位于颞叶和肿瘤中含少突胶质细胞成分,可以作为胶质瘤术后继发癫痫发作的独立预测因子。结论脑脊液谷氨酸水平的增加与脑胶质瘤患者术后继发癫痫发作的风险密切相关,脑脊液谷氨酸水平或可成为预测胶质瘤术后癫痫发生的潜在指标。     

腰池引流对破裂动脉瘤患者血浆和脑脊液ET浓度及脑血管痉挛的影响

目的探讨腰池持续引流对破裂动脉瘤患者血浆和脑脊液内皮素(ET)浓度及脑血管痉挛的影响。方法将经栓塞治疗后的破裂颅内动脉瘤患者354例分为引流组和对照组。引流组268例,栓塞后行腰池持续引流;对照组86例,每天腰穿放脑脊液一次。用放免法测定栓塞后不同时间血浆和脑脊液中ET浓度,用经颅彩色多普勒超声检测大脑中动脉血流速度。结果引流组血浆和脑脊液中ET浓度轻度增加,对照组ET浓度增加明显,两组差异显著(P<0.01)。引流组大脑中动脉平均血流流速轻度增加,对照组明显增加,两组差异显著(P<0.01)。血浆和脑脊液中ET浓度与脑动脉血流速度呈正相关(r=0.95,P<0.01)。结论蛛网膜下腔出血后脑血管痉挛与血浆和脑脊液中ET浓度异常增加有关,腰池持续引流能够有效地清除引起脑血管痉挛的因子。     

CNTF对大鼠脊髓运动神经元NF积聚影响的研究

目的 观察肌萎缩侧索硬化症（ALS）病人脑脊液和谷氨酸对体外培养SD大鼠脊髓前角运动神经元损伤及神经细丝（Neurofilament,NF）积聚的变化,探讨睫状神经营养因子（Ciliary neurophic　factor,CNTF）保护运动神经元的作用机制。方法 体外培养SD大鼠脊髓前角运动神经元,然后分组观察正常脑脊液、ALS病人脑脊液和谷氨酸对神经元损伤作用及CNTF的保护作用,免疫组化观察各组神经元中神经细丝NF积聚的情况。结果　ALS病人脑脊液和谷氨酸对体外培养的运动神经元有明显损伤作用,神经元数量减少（P<0.05）,免疫组化显示有明显的NF积聚现象,但先加入CNTF后,运动神经元数量无明显变化（P>0.05）,免疫组化显示无明显NF积聚的现象。结论 体外培养SD大鼠脊髓前角运动神经元,在加入CNTF后,可以减少ALS病人脑脊液和谷氨酸对运动神经元的直接损伤作用,并显示有抑制NF积聚的作用,提示CNTF确有保护神经元的作用。     

G-CSF对肌萎缩侧索硬化细胞外谷氨酸摄取和抗自由基作用的影响

目的研究在肌萎缩侧索硬化的体外模型中,粒细胞集落刺激因子(G-CSF)是否可以通过促进细胞外谷氨酸摄取和抗自由基作用发挥对运动神经元的保护作用。方法取8日龄SD乳鼠断头处死,取脊髓切片后放入培养液中构建脊髓器官模型。将构建的脊髓器官模型随机分为对照组、肌萎缩侧索硬化症(ALS)模型组和G-CSF组。对照组不做任何处理,仍常规培养;ALS模型组按照Matyja等人的方法加入THA和PDC构建ALS模型;G-CSF组在ALS模型组处理的基础上再加入重组人粒细胞集落刺激因子。在培养的1w、2w、3w、4w时对各组培养液中的Glu进行测定,并在第4w测定培养液中超氧化物歧化酶(SOD)、丙二醛(MDA)含量,免疫组化染色计数各组前角存活的运动神经元。结果对照组培养液中Glu浓度较低,并且随时间变化(1w、2w、3w、4w)不大,基本维持在恒定水平;ALS模型组和G-CSF组培养液中Glu浓度随时间延长逐渐增加,2w后G-CSF组Glu浓度显著低于ALS组(P0.05)。第4周时ALS模型组脊髓前角中SOD活性显著低于对照组(P0.05),G-CSF组SOD活性高于ALS模型组(P0.05),但仍低于对照组(P0.05)。结论 G-CSF有显著的抗自由基和抗兴奋性毒性作用并明显减少脊髓前角运动神经元的凋亡和缺失,可能为肌萎缩侧索硬化提供新的治疗方向。     

肌萎缩侧索硬化患者血浆转化生长因子-α水平的变化及其意义

目的探讨肌萎缩侧索硬化(ALS)患者血浆转化生长因子-α(TGF-α)水平及其临床意义。方法采用MILLIPLEX MAP液相芯片技术检测ALS患者血浆TGF-α水平,针对该指标,进行统计学分析,系统研究ALS患者与正常对照的关系、患者亚组(性别亚组、年龄亚组、病程亚组、起病部位亚组、功能评分亚组)与正常对照之间的关系。结果与正常对照相比,ALS患者血浆TGF-α水平显著升高(P0.05),各个患者亚组血浆TGF-α水平均显著升高(均P0.05);病程12个月患者比病程≤12个月患者的血浆TGF-α水平显著升高(P0.05),而其它患者亚组之间,血浆TGF-α水平均无统计学差异(均P0.05);此外,该指标水平变化与病程统计正相关(RRho=0.314,P=0.030)。结论血浆TGF-α在ALS的炎症机制中可能起到促进病情进展的作用,该指标有可能会成为推断疾病进展的潜在生物学标记。本文的相关试探性研究有望为酪氨酸激酶抑制剂等治疗ALS的措施提供更多的理论依据。     

Cholesterol Depletion from the Plasma Membrane Impairs Proton and Glutamate Storage in Synaptic Vesicles of Nerve Terminals

We report that cholesterol depletion with methyl-β-cyclodextrin (MβCD) acutely applied to rat brain synaptosomes is accompanied by an immediate increase in transporter-mediated glutamate release and decrease in exocytotic release. To clarify the possible mechanisms underlying these phenomena, we investigated the influence of MβCD on synaptic vesicle acidification and exo/endocytotic process in nerve terminals. As shown by acridine orange fluorescence measurements, the application of MβCD to synaptosomes, as well as to isolated synaptic vesicles, led to the gradual leakage of the protons from the vesicles, whereas the application of MβCD complexed with cholesterol stimulated additional vesicle acidification and an increase in Ca²⁺-dependent exocytotic response. It was found that the treatment of nerve terminals with MβCD did not block Ca²⁺-triggered vesicle recycling. We suggest that cholesterol depletion of the plasma membrane with MβCD induces the removal of cholesterol from the membrane of synaptic vesicles resulting in immediate dissipation of synaptic vesicle proton gradient and redistribution of the neurotransmitter between the vesicular and cytosolic pools. The latter appears to be the main cause of a dramatic decrease in exocytotic and considerable increase in transporter-mediated release of l-[¹⁴C]glutamate.     

Rapid Desensitization of the Metabotropic Glutamate Receptor that Facilitates Glutamate Release in Rat Cerebrocortical Nerve Terminals

The metabotropic autoreceptor of glutamatergic nerve terminals from the cerebral cortex of adult rats has been characterized. Receptor activation involves a rapid and transient increase in diacylglycerol, which is sensitive to l-2-amino-3-phosphonopropionate (l-AP3) and l-2-amino-4-phosphonobutanoic acid (l-AP4) and is partially blocked by pertussis toxin. Protein kinase C (PKC) has a negative feedback control in this transduction pathway because the activation of the kinase, either by phorbol esters or by the endogenous diacylglycerol produced by the receptor, results in a reversible receptor desensitization, with loss of the ability to further facilitate glutamate release. It is concluded that the facilitatory metabotropic receptor located at the glutamatergic nerve endings belongs to the subclass coupled to phosphoinositide hydrolysis and that the rapid and use-dependent desensitization of the facilitatory pathway may underlie a mechanism to prevent its permanent activation and thereby to avoid neurotoxicity.     

Glutamate receptor antagonists for neuroleptic malignant syndrome and akitetic hyperthermic Parkinsonian crisis

Summary Schizophrenia and Parkinson's disease have been considered inversely related neuropsychiatric disorders since the former has been attributed to increased dopaminergic transmission while the latter is thought to result from loss of dopaminergic neurons. It is in line with this concept that the classical neuroleptic (anti-schizophrenic) drugs cause as a side effect a drug-induced type of Parkinsonism. Most etiopathogenetic models hold that the neuroleptic malignant syndrome may result from overtherapy of schizophrenia, causing too widespread a block of dopaminergic transmission. The same clinical condition can be triggered by rapid discontinuation of dopaminergic medication in Parkinson's disease. Further, neuroleptic malignant syndrome shares key clinical features such as extrapyramidal motor disturbances and hyperthermia with a severe form of clinical deterioration in Parkinson's disease patients, the akinetic Parkinsonian crisis. Both conditions, neuroleptic malignant syndrome and Parkinsonian crisis, are resistant to anticholinergic treatment but may well respond to drugs with N-methyl-D-aspartate (NMDA) antagonistic properties such as amantadine and memantine. We advocate the use of NMDA receptor antagonists in these medical emergencies and link their clinical efficacy to the common pathophysiological pathway of increased excitatory aminoacid neurotransmitter activity in neuroleptic malignant syndrome, Parkinsonian crisis, and dopamine agonist withdrawal states.     

Plasma prolactin and severe premenstrual tension

It has been suggested that elevated luteal phase prolactin (PRL) levels may have an important role in causing some of the symptoms of the premenstrual tension syndrome (PMTS). Thirty-seven women suffering from severe premenstrual dysphoria were selected for this study. Single morning and afternoon serum PRL evaluations were performed during the follicular (day 9) and late luteal (day 26) phases of the menstrual cycle. PRL was measured by an established double antibody radioimmunoassay technique. All mean PRL values were within the normal range. Only afternoon mean PRL levels showed a tendency for a premenstrual increase. The significance of this statistical finding is unclear, since one-third of the subjects showed a decrease in premenstrual PRL levels. Twenty-four hour PRL secretory profiles recorded on days 9 and 26 in two women with extremely severe PMTS and in two asymptomatic matched control subjects also failed to show a significant correlation between PRL levels and PMTS. Thirty subjects participated in a treatment trial using bromocriptine. A marked rebound hyperprolactinemia was observed in a subgroup of women nine days after cessation of bromocriptine. This was associated with no detectable effect on mood, behavior, or menstrual regularity. Thus, our data fail to show any specific relationship between PRL and PMTS.     

Distinct Plasma Profile of Polar Neutral Amino Acids, Leucine, and Glutamate in Children with Autism Spectrum Disorders

The goal of this investigation was to examine plasma amino acid (AA) levels in children with Autism Spectrum Disorders (ASD, N?=?27) and neuro-typically developing controls (N?=?20). We observed reduced plasma levels of most polar neutral AA and leucine in children with ASD. This AA profile conferred significant post hoc power for discriminating children with ASD from healthy children. Furthermore, statistical correlations suggested the lack of a typical decrease of glutamate and aspartate with age, and a non-typical increase of isoleucine and lysine with age in the ASD group. Findings from this limited prospective study warrant further examination of plasma AA levels in larger cross-sectional and longitudinal cohorts to adequately assess for relationships with developmental and clinical features of ASD.     

谷氨酸与卒中后抑郁

卒中后抑郁是脑血管病后的常见并发症,严重影响了患者的生活,延长了康复治愈的时间,增加了致残率和致死率,加重了患者和家属的疾病负担。其发病机制尚未完全明了,治疗上主要以抗抑郁的精神药物为主。但是目前常用的抗抑郁药绝大多数以增加5-羟色胺和去甲肾上腺素的突触利用率为目标。这些抗抑郁药的效果不超过60%～65%,并需要2～4周才能发挥其疗效,近年的研究发现“谷氨酸及其受体”也参与抑郁症的发病机制。本文就卒中后抑郁与谷氨酸及其受体的关系方面的研究进行综述。     

Glutamate and anxiety disorders

Anxiety disorders are among the most prevalent psychiatric disorders, but they represent a particular challenge for treatment. The standard first-line treatments, including antidepressants, benzodiazepines, and buspirone, result in significant response rates for a majority of patients; however, unfavorable side effect profiles or risk for dependency for particular agents might limit their use by anxious patients, who often have low thresholds for medication discontinuation. Novel pharmacologic agents that modulate particular receptors, ion channels, or transporters relevant to glutamatergic neurotransmission may represent a new approach to the treatment of anxiety disorders, with generally more favorable side effect profiles. Although the role of glutamate in the pathophysiology of anxiety disorders is still being elucidated, the use of these agents in treatment of anxiety disorders and commonly comorbid conditions such as substance abuse and mood disorders will continue to increase.     

Glutamate and the biology of gliomas

Several important and previously unrecognized roles for the neurotransmitter glutamate in the biology of primary brain tumors have recently been elucidated. Glutamate is produced and released from glioma cells via the system x(c) (-) cystine glutamate transporter as a byproduct of glutathione synthesis. Glutamate appears to play a central role in the malignant phenotype of glioma via multiple mechanisms. By binding to peritumoral neuronal glutamate receptors, glutamate is responsible for seizure induction and similarly causes excitotoxicity, which aids the expansion of tumor cells into the space vacated by destroyed tissue. Glutamate also activates ionotropic and metabotropic glutamate receptors on glioma cells in a paracrine and autocrine manner. α-Amino-3-hydroxy-5-methyl-4-isoaxazolepropionate acid (AMPA) glutamate receptors lack the GluR2 subunit rendering them Ca(2+) permeable and capable of activating the AKT and MAPK pathways. Furthermore, these receptors are critical in aiding the invasion of glioma cells into normal brain. AMPA-Rs accumulate at focal adhesion sites where they may indirectly mediate interactions between the extracellular matrix and integrins. Glutamate receptor stimulation results in activation of focal adhesion kinase, which is critical to the regulation of growth factor and integrin-stimulated cell motility and invasion. The multitude of effects of glutamate on glioma biology supports the rationale for pharmacological targeting of glutamate receptors and transporters. Several ongoing and recently completed clinical trials are exploring the therapeutic potential of interrupting glutamate-mediated brain tumor growth.     

Glutamate transporters and retinal excitotoxicity

Glutamate appears to play a major role in several degenerative retinal disorders. However, exogenous glutamate is only weakly toxic to the retina when glutamate transporters on Müller glial cells are operational. In an ex vivo rat retinal preparation, we previously found that exogenous glutamate causes Müller cell swelling but does not trigger excitotoxic neurodegeneration unless very high concentrations that overwhelm the capacity of glutamate transporters are administered. To determine the role of glutamate transporters in Müller cell swelling and glutamate-mediated retinal degeneration, we examined the effects of DL-threo-beta-benzyloxyaspartate (TBOA), an agent that blocks glutamate transport but that unlike most available transport inhibitors is neither a substrate for transport nor a glutamate receptor agonist. We found that TBOA triggered severe retinal neurodegeneration attenuated by ionotropic glutamate receptor antagonists. TBOA-induced neuronal damage was also diminished by riluzole, an agent that inhibits endogenous glutamate release. In the presence of riluzole, to inhibit glutamate release plus TBOA to block glutamate uptake, the addition of low concentrations of exogenous glutamate triggered severe excitotoxic neuronal damage without inducing Müller cell swelling. We conclude that TBOA-sensitive glutamate transporters play an important role in regulating the neurodegenerative effects of glutamate in the rat retina.