A prospective study of recurrent febrile seizures.

BACKGROUND. Febrile seizures occur in about 2 to 4 percent of all children, approximately one third of whom will have recurrent febrile seizures. Little is known about predictors of recurrence. METHODS. In this prospective study, we identified 347 children (1 month to 10 years of age) who presented with a first febrile seizure at one of four pediatric emergency departments. Information about these children was collected from medical records and interviews with the parents, and the children were followed for a median of 20 months to ascertain whether febrile seizures recurred. RESULTS. Recurrent febrile seizures occurred in 94 of the 347 children (27 percent) with a cumulative risk of 25 percent at one year and 30 percent at two years. The duration of fever before the initial seizure was associated with the risk of recurrence at one year: for fever lasting less than 1 hour, the risk of recurrence was 44 percent; for fever lasting 1 to 24 hours, 23 percent; and for fever lasting more than 24 hours, 13 percent (P less than 0.001). With each degree of increase in temperature (in degrees Fahrenheit), from 101 degrees F (38.3 degrees C) to greater than or equal to 105 degrees F (40.6 degrees C), the risk of recurrence at one year declined, from 35 percent to 30, 26, 20, and 13 percent (P for trend = 0.024). An age of less than 18 months and a family history of febrile seizures were also associated with an increased risk of recurrence. A family history of epilepsy, complex febrile seizures, and neurodevelopmental abnormalities did not increase the risk of recurrent febrile seizures. CONCLUSIONS. A shorter duration of fever before the initial febrile seizure and a lower temperature are associated with an increased risk of recurrence in children who have febrile seizures.     

反复热性惊厥过程中气体信号分子硫化氢对一氧化氮/一氧化氮合酶体系的影响

目的：探讨硫化氢（H₂S）对热性惊厥（FS）大鼠一氧化氮（NO）/一氧化氮合酶（NOS）体系表达的影响。方法:大鼠随机分为对照组、FS组、FS+NaHS组、FS+HA（hydroxylamine）组。采用热水浴诱导大鼠FS，隔日诱导1次，共10次。采用分光光度计法测定大鼠血浆中H₂S和NO含量；用原位杂交观察nNOS mRNA表达情况；用免疫组化方法观察NOS蛋白表达情况。结果:FS+NaHS组NO含量低于FS组，同时NOS表达也低于FS组；而FS+HA组NO含量高于FS组，同时NOS表达也强于FS组。结论:用H₂S外源性供体NaHS和胱硫醚-β-合成酶抑制剂HA的干预研究表明，反复热性惊厥过程中，H₂S的改变可影响NO/NOS体系的表达。     

Absence of modifications in gamma-aminobutyric acid metabolism after repeated generalized seizures in amygdala-kindled rats

Alterations in gamma-aminobutyric acid (GABA) metabolism have been investigated in the kindling model of epilepsy. Numerous generalized seizures were induced by amygdala-kindling stimulations in rats. One week after the last stimulation, there were no changes in GABA levels nor in the activity of enzymes responsible for the synthesis (glutamic acid decarboxylase) and catabolism (GABA transaminase and succinyl semialdehyde dehydrogenase). These results do not exclude other changes in GABA function as modifications of transport or receptors.     

Nitric oxide-mediated neuronal apoptosis in rats with recurrent febrile seizures through endoplasmic reticulum stress pathway

Nitric oxide (NO), as a neurotransmitter, exerts various physiological and pathological effects on the brain. Excess NO is toxic to neurons and may cause neuronal apoptosis. However, the cascade of NO-mediated apoptosis is not fully understood. We utilized a recurrent febrile seizures (FS) rat model and found that plasma NO was increased, neuronal apoptosis was evident, the expression of glucose-regulated protein78 (GRP78, a well-established marker of ER stress) was elevated, and caspase-12 (an ER stress-specific proapoptosis molecule) was activated in the hippocampus in a time-dependent manner after recurrent FS. Administration of sodium nitroprusside (SNP, an NO donor) enhanced neuronal apoptosis, down-regulated the expression of GRP78, and increased that of caspase-12 in FS+SNP groups compared with FS groups. In contrast, treatment with N(G)-nitrol-l-arginine methyl ester (l-NAME, a competitive NO synthase inhibitor) inhibited neuronal apoptosis, up-regulated the expression of GRP78, and decreased that of caspase-12 in FS+l-NAME groups compared with FS groups. These results suggest that NO mediates neuronal apoptosis caused by recurrent FS, and that the ER stress pathway is involved in NO-mediated neuronal apoptosis.     

Ontogeny of susceptibility to experimental febrile seizures in rats

Two experiments were conducted using microwave hyperthermia (MHT) to induce seizures among limited numbers of Long-Evans rat pups. The MHT model of febrile seizures eliminates several methodological complications inherent in previous animal models of the disorder. In Experiment 1, rat pups were rendered hyperthermic with MHT or were sham-irradiated on Days 11, 13, 15 or 17 postpartum. The results indicate a statistically significant decline in seizure susceptibility with age. In Experiment 2, rats were subjected to either single or multiple hyperthermic episodes on Days 11, 13, 15, or 17 postpartum. The results indicate an increase in susceptibility to seizures attributable to prior seizure history. In both experiments, seizures were induced with increases in rectal temperature of 1 to 3 degrees C. The results parallel many clinical features of febrile seizures and argue the efficacy of the MHT model.     

硫化氢对蛛网膜下腔出血大鼠额顶叶脑区神经损伤的保护作用

目的 探讨外源性硫化氢对蛛网膜下腔出血(SAH)大鼠早期脑损伤的保护作用及可能机制.方法 30只清洁级SD大鼠随机分成3组:对照组、SAH模型组、硫化氢作用组,每组各10只.后两组大鼠应用大脑中动脉穿刺法制作SAH模型,硫化氢组于模型制作成功后立即腹腔注射100mg/kg硫氢化钠.各组大鼠24h后进行神经功能评分,取额顶叶脑组织,用免疫荧光和Western blotting等方法检测额顶叶脑区神经细胞GFAP、S-100b、B淋巴细胞瘤-2基因(Bcl-2)、Caspase-3、c-Fos、基质金属蛋白酶-9(MMP-9)蛋白表达的变化.结果 硫化氢组与SAH组相比神经功能评分有明显改善(P＜0.01).硫化氢组神经评分得3分以上的只有2只动物,而SAH组有8只.免疫荧光结果显示,SAH组GFAP、S-100b蛋白表达较对照组明显增高(P＜0.05);硫化氢作用后两者表达较SAH组明显下降(P＜0.05).SAH组Bcl-2、Caspase-3均有表达,硫化氢作用后Bcl-2表达明显增加,而Caspase-3则明显下降(P＜0.05).Western blotting结果进一步显示,SAH组c-Fos、MMP-9表达较对照组均明显增高(P＜0.05);硫化氢作用后两者表达则明显下降(P＜0.05).结论 硫化氢对SAH后脑损伤有明显保护作用,其机制可能与改善胶质细胞的功能及与凋亡机制有关.     

COX-2抑制剂对幼鼠反复癎性发作后神经发生的影响

目的:研究环氧合酶-2(COX-2)在癎性发作活化后的表达特点,探讨COX-2抑制剂塞莱昔布(celecoxib,Cel)对癎性活动后海马区神经发生的影响.方法:模型制作:随机将120只体重为50～60 g的3周龄健康Wistar幼鼠分为匹鲁卡品致癎组(EP-Only组)(n=45)和Cel干预致癎组(EP-Cel)(n=45)和生理盐水正常对照组(NS组)(n=30)3组.随机在EP-only及EP-Cel组各取10只匹鲁卡品成功诱导急性发作幼鼠进行腹腔注射溴脱氧尿核苷(BrdU):(1)行为学观察:根据Racine分级评价急性期和慢性期癎性发作行为;(2)形态学检测:各实验组分别在急性发作后第14天,第28天处死大鼠制备组织切片进行免疫组化检测COX-2阳性细胞在各组的表达变化趋势,以及BrdU+神经元特异性核蛋白(NeuN)和BrdU+星形胶质细胞胶原纤维酸性蛋白(GFAP)荧光免疫双标阳性细胞的表达,观察神经前体细胞的增殖及分化在各组的差异.结果:(1)动物行为学观察:在急性期,EP-only组全身性自发反复性癫癎发作(SRS)发作率(90%)明显高于EP-Cel组(56%)(P<0.01);EP-only组癎性发作Racine分级强度(3.7±1.3)明显高于EP-Cel组发作强度(2.5±1.1)(P<0.05);在慢性期,EP-Only组SRS发生率(50%)明显高于EP-Cel组(30%)(P<0.05;X<'2>检验);EP-Only组平均每天SRS发生的频率(1.9±0.58)明显高于EP-Cel组(0.6±0.3)(P<0.01,t检验);(2)形态学检测免疫组化结果:①COX-2免疫反应阳性细胞的表达:匹鲁卡品致癎第14天后,海马区COX-2阳性细胞表达在EP-Only组明显高于EP-Cel组L(158±18)vs(118±20)](P<0.01);②BrdU+NrdU和BrdU+GFAP免疫双标结果:急性期发作第28天后,BrdU+NeuN免疫双标阳性细胞在EP-Only组明显高于EP-Cel组[(36±4)vs(22±3)];同时EP-Only组门区有BrdU+GFAP免疫双标阳性的新生的胶质细胞明显比EP-Cel组高[(26±3)vs(14±2)].结论:COX-2在癎性发作后被迅速诱导表达,COX-2抑制剂Cel能抑制癎性发作激活的异常神经发生和星形胶质细胞增生,减少慢性期SRS.     

反复发热惊厥大鼠脑内NOS/NO体系的变化

目的研究一氧化氮合酶(NOS),一氧化氮(NO)体系与反复发热惊厥(febrile seizures,FS)的关系。方法采用热水浴诱导大鼠FS,隔日1次,每次大鼠进行热水浴的时间不超过5min,共10次。大鼠随机分为2组：正常对照组和发热组,后者又根据惊厥与否进一步分为发热对照组和反复FS组。用原位杂交法观察大脑皮层神经元型NOS(nNOS)mRNA的变化,用分光光度计检测大鼠脑组织及血浆中NO含量,用放射免疫法检测大鼠脑组织cGMP含量。结果在大脑皮层深层,FS组nNOS表达阳性的神经元明显增高,而发热对照组仅出现少量nNOS阳性神经元,正常对照组偶见nNOS阳性神经元;脑组织及血浆中NO含量各组间无统计学意义;FS组脑组织cGMP含量吸显高于正常对照组及高热对照组。结论大鼠反复FS后24h脑内nNOS mRNA表达增高,但此时NO不见增多,脑组织cGMP水平增高,可能由于其他途径调节所致。     

Antagonistic effect of delta-aminovaleric acid on bicuculline-insensitive gamma-aminobutyric acid B (GABA B) sites in the rat's brain

The effect of delta-aminovaleric acid (delta-AV) on bicuculline-insensitive gamma-aminobutyric acid B (GABA B) sites in the central nervous system (CNS) was investigated by binding studies and experiments on slices in vitro. delta-AV inhibited [3H]GABA (10 nM) binding to GABA B sites in a rat brain membrane preparation with an IC50 value of 10(-4) M. It also inhibited [3H]baclofen (20 nM) binding with an IC50 value of 10(-4) M. In preparations of hippocampal slices, (-)-baclofen (5 microM) reduced the population spikes evoked by stimulating the Schaffer collaterals in CA1 pyramidal cells in the presence of 100 microM bicuculline. delta-AV (1 mM) antagonized this inhibitory action of baclofen. Since baclofen is an agonist of GABAB sites, our results indicate that delta-AV has an antagonistic effect on GABAB sites in the CNS.     

Ginkgolide B increases hydrogen sulfide and protects against endothelial dysfunction in diabetic rats

AimTo evaluate the effect of ginkgolide B treatment on vascular endothelial function in diabetic rats.MethodsThe study included four groups with 15 male Sprague-Dawley rats: control group; control group treated with ginkgolide B; diabetic group; and diabetic treated with ginkgolide B. The activity of superoxide dismutase (SOD), malondialdehyde content, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits, and glutathione peroxidase 1 (GPX1) protein expression were determined in aortic tissues. Vasoconstriction to phenylephrine (PHE) and vasorelaxation to acetylcholine (Ach) and sodium nitroprusside (SNP) were assessed in aortic rings. Nitric oxide (NO) and hydrogen sulfide (H₂S) were measured, as well as cystathionine γ lyase (CSE) and cystathionine β synthetase (CBS) protein expression, and endothelial nitric oxide synthase (eNOS) activity.ResultsDiabetes significantly impaired PHE-induced vasoconstriction and Ach-induced vasorelaxation (P < 0.001), reduced NO bioavailability and H₂S production (P < 0.001), SOD activity, and GPX1 protein expression (P < 0.001), and increased malondialdehyde content and NADPH oxidase subunits, and CSE and CBS protein expression (P < 0.001). Ginkgolide B treatment improved PHE vasoconstriction and Ach vasorelaxation (P < 0.001), restored SOD (P = 0.005) and eNOS (P < 0.001) activities, H₂S production (P = 0.044) and decreased malondialdehyde content (P = 0.014). Vasorelaxation to SNP was not significantly different in control and diabetic rats with or without ginkgolide B treatment. Besides, ginkgolide B increased GPX1 protein expression and reduced NADPH oxidase subunits, CBS and CSE protein expression.ConclusionGinkgolide B alleviates endothelial dysfunction by reducing oxidative stress and elevating NO bioavailability and H₂S production in diabetic rats.Diabetes mellitus is an endocrine disease caused by decreased insulin secretion or action, leading to impaired glucose and lipid metabolism (1). The most dangerous complication of diabetes mellitus is cardiovascular disease, which is the primary factor leading to high mortality and morbidity in diabetic patients (2). A critical role in diabetic cardiovascular complications is played by endothelial dysfunction. Mechanisms responsible for endothelial dysfunction are still poorly understood, but hyperglycemia-induced oxidative stress is hypothesized to be one of them (3). Increased blood glucose increases reactive oxygen species (ROS) production via glucose auto-oxidation (4) and variation in activity of oxidoreductases, such as NADPH oxidase (5). ROS can impair vascular function by damaging endothelial cells, thus playing an important role in diabetes and its cardiovascular complications (6). NADPH oxidase is important because it generates ROS (7,8). Glutathione peroxidase 1 (GPX1) is one of the pivotal antioxidant enzymes in vascular endothelium, which protects against the presence of coronary artery disease (9). Its overexpression reduces ROS formation and enhances phosphorylation of endothelial nitric oxide synthase (eNOS), which improves endothelial function (10).Hydrogen sulfide (H₂S) was previously considered only as a toxic gas, but recent studies have suggested that it plays a variety of important physiological and physiopathological roles (11,12). H₂S is generated from L-cysteine by several enzymes including cystathionine γ lyase (CSE) and cystathionine β synthetase (CBS). Some studies have shown that H₂S takes part in modulation of cardiovascular system (13,14). It has also been shown that H₂S biosynthesis is impaired in diabetes, and that it may be effective to administer different H₂S donors to diabetic animals (15,16).The risk of endothelial dysfunction is increased by sustained progression of hyperglycemia and hyperlipidemia. Endothelial dysfunction is characterized by alterations of endothelium-dependent vascular response to vasoconstrictors and vasodilators in diabetic animals (17,18). Therefore, cardiovascular complications including endothelial dysfunction in patients with diabetes have been treated by decreasing blood glucose and lipid content, and reducing activation of angiotensin. However, these treatments have not prevented the development of complications (19), emphasizing the need for novel approaches.Ginkgolide B, a plant-derived terpenoid, is one of natural bioactive components from the extract of ginkgo biloba leaves. Many studies have demonstrated that ginkgolide B can inhibit platelet-activating factor (PAF)-induced platelet activation via binding with PAF receptor (20,21). Therefore, ginkgolide B is widely used as a natural antagonist of PAF and inhibitor of PAF-induced inflammatory reaction (22). It has been shown that ginkgolide B regulates many physiologic functions, including the antioxidant function, improving the cognitive functions of central nervous system (23,24), repressing atherosclerosis (25), and abating liver cirrhosis (26). In this study, we investigated the effects of ginkgolide B on endothelial function and mediators such as hydrogen sulfide (H₂S), biomarkers of oxidative stress, and oxidoreductase in the aorta of rats with streptozotocin-induced diabetes.     

外源性硫化氢对大鼠血管钙化的影响

目的观察外源性给予硫化氢(H2S)对血管钙化的影响。方法用肌注维生素D3和灌胃尼古丁诱导大鼠血管钙化,运用Von Kossa染色、原子吸收测定钙含量4、5Ca2 沉积及碱性磷酸酶(ALP)活性测定判断血管钙化程度,半定量RT-PCR方法测定骨桥蛋白(OPN)mRNA水平。结果钙化组大鼠血管Von Kossa染色见平滑肌细胞内和细胞间基质有大量黑色颗粒聚集;主动脉钙含量、45Ca2 沉积及ALP活性分别较对照高6.8倍、1.4倍和1.9倍(P<0.01),OPN mRNA表达明显上调;低、高剂量NaHS组均明显缓解上述指标的变化(P<0.01)。结论补充H2S可减轻钙化血管的钙化程度。     

Long-term effects of neonatal seizures on subsequent N-methyl-D-aspartate receptor-1 and gamma-aminobutyric acid receptor A-alpha 1 receptor expression in hippocampus of the Wistar rat

To evaluate the pathophysiological mechanism of subsequent reduced seizure threshold following neonatal seizures, single or recurrent prolonged seizures were induced to neonatal rats by the inhalant flurothyl. The expression of N-methyl-d-aspartate receptor 1 (NR1) and gamma-aminobutyric acid receptor A-alpha 1 (GABA-A-alpha 1) immunoreactivity in hippocampus were examined by Western blotting analysis at the day 7 (P7) and day 75 (P75) after the last seizure. Whereas there were no significant changes in single seizure group and recurrent seizure group of P75, NR1 expression enhanced significantly in P7 rats of recurrent seizure group. Meanwhile, polypeptide levels of GABA-A-alpha 1 receptor subunit decreased significantly in both single and recurrent seizure-treated P7 and P75 rats. Our results suggest that recurrent or single prolonged seizures during the neonatal period may have long-term effects on the balance between excitatory NMDA system and inhibitory GABA system in hippocampus of rats.     

CCK-8对脂多糖性肺损伤大鼠肺组织中硫化氢生成的抑制作用

目的： 探讨硫化氢（H2S）在八肽胆囊收缩素(CCK-8)改善脂多糖性肺损伤中的作用。方法：用静脉注射脂多糖（LPS,5 mg/kg）法制备大鼠肺损伤模型,将雄性Wistar大鼠随机分为正常对照组、LPS组、LPS+CCK-8组及CCK-8组。给药后6 h测定大鼠动脉血氧分压（PaO2）;检测肺组织中H2S含量和胱硫醚-γ-裂解酶(CSE)活性;RT-PCR检测肺组织CSE mRNA的表达;光镜观察肺组织的形态学变化。结果：与正常对照组相比,LPS组大鼠PaO2显著下降并出现肺组织结构损伤,而肺组织中H2S含量、CSE活性和mRNA表达显著增高（均P<0.05）;与LPS组相比,LPS+CCK-8组大鼠PaO2显著升高,肺组织结构损伤明显减轻,肺组织中H2S含量和CSE活性及mRNA表达显著下降（均P<0.05）;CCK-8组大鼠上述各指标与正常对照组相比无明显差异。结论：CCK-8可通过抑制内源性H2S的生成减轻脂多糖性肺损伤。     

硫化氢对糖尿病大鼠ED的影响和机制研究

 目的：观察硫化氢（H 2S）对糖尿病（DM）大鼠勃起功能障碍（ED）的影响。方法：将70只SD雄性大鼠分为2组,60只腹腔注射链脲佐菌素（STZ）建立DM大鼠模型,10只注射生理盐水为正常对照。阿朴吗啡诱导勃起后检测DM造模成功大鼠的勃起功能情况,将存在ED的36只大鼠随机分成3组：糖尿病对照组（DM组）、糖尿病+硫氢化钠组（DM+NaHS组）和糖尿病+西地那非组（DM+sildenafil组）。DM+NaHS组每天腹腔注射NaHS （50 μmol/kg）,DM+sildenafil组每天给予西地那非（5 mg/kg）灌胃,DM组每日腹腔注射生理盐水,注射体积为0.25 mL。持续饲养12周后,观察各组大鼠勃起功能情况,采集各组大鼠动脉血,测定血液中H 2S含量及各组阴茎海绵体组织胱硫醚γ-裂解酶（cystathionine γ-lyase, CSE）活性及CSE表达水平。结果：STZ诱发的DM造模成功率为81.7%（49/60）,DM大鼠发生ED的比例为73.5%（36/49）,与DM组比,DM+NaHS组和DM+sidenafil组大鼠勃起功能良好,3个实验组大鼠勃起率分别为(33.3±5.5)%、（54.5±5.3）%和(63.6±9.1)%。与正常大鼠组比,各组DM大鼠阴茎海绵体中CSE活性与表达水平均有下降,其中DM+NaHS组大鼠的CSE活性及表达水平显著低于DM组（P<0.05）和DM+sildenafil组（P<0.05）。结论：STZ诱导的糖尿病大鼠中ED发生率较高,H 2S对糖尿病合并ED大鼠勃起功能有一定的促进作用。外源性给予H 2S可以反馈性抑制大鼠阴茎组织中CSE的活性和表达。     

硫化氢对神经退行性疾病保护作用的研究进展

硫化氢(hydrogen sulfide,H2S)一直被认为是一种有毒气体.近年来,越来越多的研究显示H2S在哺乳动物体内可以调节及参与一定范围的生理和病理过程.H2S在中枢神经系统中扮演着重要的角色.H2S具有抗氧化应激、抗凋亡以及抗炎的作用,而这些生理学意义对研究防治包括阿尔茨海默病、帕金森氏病在内的神经退行性疾病有着重要的启示.     

外源性硫化氢对糖尿病动脉内皮的保护作用

动脉粥样硬化(AS)是血管病变的病理基础,血管内皮功能紊乱是AS病理变化的早期表现之一。硫化氢(H_2S)是继一氧化氮(NO)和一氧化碳(CO)之后的第三个具有生理功能的气体信号分子。H_2S发挥着广泛的生物学效应,对内皮细胞增殖、迁移,抗氧化应激,调节血管紧张度都有一定的影响。H_2S可以使血管舒张,抑制炎症反应和白细胞黏附,抑制血管增殖,抗血栓形成。H_2S是一种还原性气体分子,可以抑制线粒体超活性氧(ROS)的产生,清除或中和ROS,有助于内源性抗氧化分子的生成,进而抑制氧化应激,保护血管内皮,维持器官的血流灌注量     

合成红藻氨酸诱发大鼠癫痫作用的研究

目的: 观察合成红藻氨酸(SKA) 诱发大鼠癫痫的作用及其作用特点。方法: Wistar大鼠40只,随机分为正常对照组、SKA 12 mg/kg、SKA 10 mg/kg 和 SKA 5 mg/kg 剂量组及红藻氨酸 (KA)10 mg/kg阳性对照组。腹腔注射给药,连续8 h观察大鼠癫痫发作的行为学变化及连续3.5 h记录其脑电图变化。结果: 合成红藻氨酸5、10、12 mg/kg 腹腔注射,可诱发大鼠癫痫发作,其行为学及脑电改变与KA对照组无明显差异。但合成红藻氨酸诱发动物癫痫呈现规律、稳定及阶段性明显的特征,且大鼠的死亡率较天然红藻氨酸低。结论: 合成红藻氨酸腹腔注射可诱发大鼠癫痫发作,以10 mg/kg为较合适剂量。     

Brain gamma-aminobutyric acid and benzodiazepine receptor binding in dialysis encephalopathy

We measured gamma-aminobutyric acid (GABA) and benzodiazepine binding in autopsied frontal cortex of 8 patients dying with dialysis encephalopathy (DE). No alteration in [3H] GABA binding was observed. However, a mild reduction (-23%, P less than 0.05) of [3H] flunitrazepam-binding density was found in DE cortex. The magnitude of this reduction was similar to that observed in frontal cortex of amygdala-kindled rats [10]. We suggest that a reduction in benzodiazepine receptor number, in combination with markedly reduced GABA concentration in DE cerebral cortex may contribute to some of the clinical features (especially seizures) characteristically observed in this syndrome.