视频脑电图在小儿癫痫诊断中的应用

目的评价视频脑电图(video-EEG)在小儿癫诊断中的应用价值。方法对126例具有发作性症状的患儿进行连续8h的包括清醒、睡眠、诱发试验及必要的认知测验的视频脑电图监测。结果经发作期视频脑电图证实,39例初诊为癫性发作的患儿中14例(35%)为非癫性发作;15例其他症状发作中13例(86%)为非癫性发作。64例样放电患儿中51例(80%)确定发作类型,22例(34%)确定癫类型。视频脑电图可发现短暂轻微的癫发作及样放电引起的一过性认知损伤。结论视频脑电图在排除非癫性发作、确定癫性发作的类型、评价脑电-临床关系方面可提供准确可靠的证据,进一步提高癫的临床诊断水平。     

Role of glutathione in repair of free radical damage in hippocampus in vitro.

Depletion of glutathione (GSH), an intrinsic antioxidant, increases vulnerability to free radical damage in a number of cell systems. This study investigates the role of GSH in limiting electrophysiological damage and/or recovery from free radical exposure in slices of guinea pig hippocampus. Synaptic potentials (PSPs) and population spikes (PSs) were recorded from field CA1. Free radicals were generated from 0.006% peroxide through the Fenton reaction. Analysis of the input-output curves showed that peroxide treatment decreased PSPs and impaired ability of the PSPs to generate PSs as previously reported. Recovery was nearly total within a half hour. Treatment with 5 mM buthionine sulfoximine (BSO) for 2 h depleted hippocampal GSH to 79.2% of control values. The extent of free radical damage was not increased. Recovery, however, was only partial. GSH was further depleted by oxidation with diamide or covalent bonding with dimethyl fumarate (DMF) immediately before and during the peroxide treatment. Neither diamide nor DMF treatment in BSO-incubated tissue enhanced peroxide-induced electrophysiological deficits. Following these treatments, however, tissue showed little recovery from free radical damage. We conclude that glutathione is essential for repair processes in hippocampal neurons exposed to oxidative damage.     

Storage of lipofuscin in neurons in mucopolysaccharidosis

Summary A histochemical and ultrastructural study was made on the brain of a 23-year-old man with Sanfilippo's syndrome. In accordance with previous reports the cortical nerve cells contained a PAS-positive lipid storage substance. This showed intense autofluorescence in UV-light and was positive with various stains for lipofuscin. The storage material appeared ultrastructurally as inclusion bodies composed of short lamellated membranes, granular material, and vacuoles. In addition, concentrically and transversely lamellated membranous cytoplasmic bodies were observed in the nerve cells. It is concluded that the PAS-positive lipid storage material in the neurons was composed partly of lipofuscin in addition to other lipids presumably glycosphingolipids.Supported by a grant from the Expressen Prenatal Research Foundation     

Neuroprotective properties of memantine in different in vitro and in vivo models of excitotoxicity

The pathogenesis of stroke, trauma and chronic degenerative diseases, such as Alzheimer's disease (AD), has been linked to excitotoxic processes due to inappropriate stimulation of the N-methyl-D-aspartate receptor (NMDA-R). Attempts to use potent competitive NMDA-R antagonists as neuroprotectants have shown serious side-effects in patients. As an alternative approach, we were interested in the anti-excitotoxic properties of memantine, a well-tolerated low affinity uncompetitive NMDA-R antagonist presently used as an anti-dementia agent. We explored in a series of models of increasing complexity, whether this voltage-dependent channel blocker had neuroprotective properties at clinically relevant concentrations. As expected, memantine protected neurons in organotypic hippocampal slices or dissociated cultures from direct NMDA-induced excitotoxicity. However, low concentrations of memantine were also effective in neuronal (cortical neurons and cerebellar granule cells) stress models dependent on endogenous glutamate stimulation and mitochondrial stress, i.e. exposure to hypoxia, the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP+) or a nitric oxide (NO) donor. Furthermore, memantine reduced lethality and brain damage in vivo in a model of neonatal hypoxia-ischemia (HI). Finally, we investigated functional rescue (neuronal capacity to migrate along radial glia) by memantine in cerebellar microexplant cultures exposed to the indirect excitotoxin 3-nitropropionic acid (3-NP). Potent NMDA-R antagonists, such as (+)MK-801, are known to block neuronal migration in microexplant cultures. Interestingly, memantine significantly restored the number of neurons able to migrate out of the stressed microexplants. These findings suggest that inhibition of the NMDA-R by memantine is sufficient to block excitotoxicity, while still allowing some degree of signalling.     

Role of vincristine in the inhibition of angiogenesis in glioblastoma

Objective: Vincristine, a microtubule-destabilizing drug, was found to exhibit anti-angiogenic effects and anti-tumoral activity. However, the precise mechanism by which vincristine inhibits angiogenesis in glioblastomas is not well understood. Our aim was to investigate whether vincristine affects vascular endothelial growth factor (VEGF) expression in glioblastoma cells and determine whether it is mediated by the downregulation of hypoxia-inducible factor-1α (HIF-1α).

Methods: We investigated the expression of HIF-1α in glioblastoma tissues resected from patients and in human glioblastoma cell lines using immunohistochemistry, Western blot analysis, and immunocytochemistry. In addition to an MTT assay assessing the effect of vincristine on cell proliferation and viability, the effects of vincristine on VEGF mRNA expression and HIF-1α protein were examined using real-time RT-PCR and Western blot analysis under 1% O₂ (hypoxia).

Results: HIF-1α was expressed in the majority of glioblastoma tissues and was detected mainly in the nucleus. Strong immunoreactivity for HIF- 1 α was found often in the hypercellular zones. Under hypoxic conditions, HIF-1α protein levels in the glioblastoma cell lines increased, primarily localizing into the nucleus similar to glioblastoma tissues. Exposure of glioblastoma cells to vincristine resulted in enrichment of the G₂-M fraction of the cell cycle, which suggests that vincristine-mediated growth inhibition of glioblastoma is correlated with mitotic inhibition. Using doses lower than those found to reduce the viability and proliferation of cells by 50% (IC₅₀), vincristine decreased both the expression of VEGF mRNA and the level of HIF-1α protein in hypoxic glioblastoma cells. In addition, following exposure to vincristine, the expression of VEGF mRNA was correlated with HIF-1α protein levels.

Conclusions: Our results suggest that the mechanism by which vincristine elicits an anti-angiogenic effect in glioblastomas under hypoxic conditions might be mediated, in part, by HIF-1α inhibition.     

Expression of apoptosis-related proteins in model of anoxia in vitro

There has been growing evidence that different modes of cell death exist, among them the apoptosis is thought to be an important mechanism of nerve cell loss implicated in various pathological states. A number of proteins mediated with apoptotic process have been identified, including p53, BAX, BCL-2 and BCL-X. We examined the expression of proteins related to programmed cell death in hippocampal neurons in vitro, exposed to pure anoxia or pretreated with apoptosis modulating agents: zinc and zinc chelator - TPEN. The results evidenced the noticeable differences in the expression of pro- and anti-apoptotic proteins in particular experiments. In the cultures exposed to pure anoxia, a significant increase of p53 and BAX immunoreactivity, associated with the decreased level of BCL-2 and BCL-X immunopositive cells was observed, related to the activation of apoptotic process. Hippocampal cultures pretreated with ZnCl2 before anoxia showed decreased immunoreactivity for p53 and BAX, connected with BCL-2 overexpression, whereas the cultures exposed to zinc chelating agent - TPEN or TPEN connected with anoxia showed significant increase of immunorectivity for p53 and BAX. This strong immunoreactivity of proapototic proteins (p53 and BAX) in hippocampal cultures exposed to anoxia or/and TPEN correlated with previous ultrastructural evidences of anoxia- and TPEN-induced apoptosis, while the overexpression of anti-apoptotic protein (BCL-2 and BCL-X) in zinc-pretreated cultures evidenced the protective ability of this metal against apoptosis in model of anoxia in vitro.     

Knowledge of management of epilepsy in young adults in Jordan

PURPOSE: Nationwide studies on public knowledge of epilepsy have been undertaken in several countries, but not in Jordan. The purpose of this study was to evaluate knowledge of the management of epilepsy in Jordan. METHODS: A cross-sectional study was performed during the period February-June 2005 on 16,044 individuals selected randomly to represent all regions of Jordan. Respondents were interviewed and asked to complete a five-item questionnaire testing their knowledge of the management of epilepsy. RESULTS: Most of the individuals (77.9%) agreed that patients with epilepsy are best treated in a specialized hospital for neurological diseases. Although the largest percentage of the sample (86.7%) agreed that the best person to treat epilepsy is a neurologist, others believed that a hypnotherapist (25.4%) or a religious healer (22.6%) is. As an immediate measure during an attack of epilepsy, most respondents (82.6%) agreed that protecting the patient's head is most important. During the postseizure period, 45.8% of respondents believed that offering the patient water or a cold or hot drink is appropriate. Two-thirds of the respondents (66.2%) agreed that epilepsy can be treated with drugs. Responses of the participants to the five items significantly differed with respect to age, gender, level of education, and occupation. CONCLUSION: Jordanians are reasonably well informed about most aspects of the management of epilepsy, but there is still a need for public education about this disorder.     

Metabolism of serotonin in autism in children

In this controlled study of 22 autistic children and 22 normal controls matched for age and sex, the frequency of hyperserotonemia in infantile autism was confirmed. Platelet serotonin was elevated in patients. Comparative to controls, serotonin was also high in urine of autistic patients, while, on the contrary there was no difference for the urinary excretion of 5-HIAA. No difference was observed either for serotonin uptake and efflux or for MAO activity, in isolated platelets. The elevation of plasma free tryptophan - significant only with the Kolmogorov Smirnov test - suggests that 5-HT biosynthesis might be enhanced. In the group of patient reported in this study, disorders of serotonin metabolism are associated with disturbances of platelet catecholamines, and also with elevated immunoglobulins and enhanced cellular immunity reactions.     

脑卒中生物学标志研究进展

近年来,我国脑卒中发病率一直居高不下,每年约有(1.50～2.00)×10~6例新发病例,年病死率约116.63/10万,仅次于恶性肿瘤位列疾病死因的第2位,给社会带来的经济负担每年高达374亿元人民币。因此早期诊断、病情监测和个体化治疗显得尤为重要。除了临床症状和神经系统体格检查外,脑卒中的诊断和监测在很大程度上依赖近期迅速发展的神经影像学诊断技术,如MRI扩散加权成像(DWI)、灌注成像(PWI)、磁敏感加权成像(SWI)等,     

脑电图预测痫性发作研究进展

癫痫(epilepsy)是由脑部神经元高度同步化异常放电所致的临床综合征,系神经系统的常见病,困扰着全世界约1%的人群.每次神经元的阵发性放电或短暂的脑功能异常称为痫性发作(seizures).     

Midazolam in treatment of various types of seizures in children

Midazolam is a recently developed water-soluble benzodiazepine that shares anxiolytic, muscle relaxant, hypnotic and anticonvulsant actions with other members of this class. There are limited studies that midazolam can be used successfully to treat seizures in adults and children. In this study, 0.2 mg/kg intramuscular (IM) midazolam was administered to 11 children (eight boys and three girls), aged 3 days to 4 years (mean age 1.8±1.4 years), with seizures of various types. In all but one child, seizures stopped in 15 s–5 min after injection. No side effects were observed. These results suggest that IM administration of midazolam may be useful in a variety of seizures during childhood, especially in case of intravenous (IV) line problem.