Regulation of ERK signaling pathway in HIF-1α expression in the hippocampus of epileptic rats / 中华神经医学杂志

Objective To explore whether extracellular signal-reg-ulated kinase (ERK) signaling pathway is involved in the hypoxia-inducible factor-1α (HIF-1α) expression in the hippocampus of epileptic rats.Methods A total of 208 21-d old SD rats were equally randomized into status epilepticusgroup (SE,n=96),normal control group (NS,n=96) and PD98059 (the ERKsignaling pathway specific inhibitor) treatment group (n=16),respectively; SE rat models of the SE group were induced by intraperitoneal injection of 1％ PTZ (80 mg/kg),and rats of the NS group received injection of normal saline (NS); 0.5,1,1.5,6,12 and 24 h after the inducement,the mRNA and protein expressions of HIF-lα and ERK1/2 in the hippocampus of rats in these two groups were examined by RT-PCR and Westem blotting.For rats in the PD98059 treatment group,PD98059 was intraperitoneally injected 10 minutes before intraperitoneal injection of pentylenetetrazol; 1 h after the inducement,the mRNA expressions of HIF-1α and ERK1/2 in the hippocampus of rats were examined by RT-PCR,while 1.5 h after the inducement,the protein expressions of HIF-1α and ERK1/2 in the hippocampus of rats were examined by Western blotting.The results of the PD98059 treatment group would be compared with those of the SE group.Results Compared with the NS group,the mRNA and protein expressions of HIF-1α and ERK 1/2 in the hippocampus of rats in the SE group after SE increased significantly; the peakexpression time ofERK1/2 mRNA was 1 h after SE (1.112±0.126 h),and the ERK1/2 protein mostly expressed at 1.5 h after SE (1.127±0.155 h).As to HIF-1α mRNA and its protein,the peak expression time was 1.5 h after SE (0.589±0.090 h) and 6 h after SE (0.230±0.052 h),respectively (P＜0.05).Compared with the SE group,the mRNA and protein expressions of HIF-1α and ERK1/2 in the hippocampus of all the rats in the PD98059 treatment group after SE decreased significantly (P＜0.05);positive correlation between HIF-1α and ERK1/2 mRNA in the SE group was noted (r=0.688,P=0.000).Conclusion ERK signaling pathway is activated in the epileptic rats and it participates in the expressionof HIF-1α in the hippocampus.

Expression of hypoxia-inducible factor-1 alpha and correlation between HIF-1α level and proliferation of neural stem cells in the hippocampus of developing rats after pentylenetetrazolinduced status epilepticus / 中华神经医学杂志

Objective To explore the expressions of hypoxia-inducible factor-1 alpha (HIF- lα)and nestin in the hippocampus of developing rats after pentylenetetrazol (PTZ)-induced starus epilepticus (SE),and the correlation between HIF-1α level and proliferation of neural stem cells (NSCs). Methods A total of 768 SD rats,including rats of postnatal 7 days (P7,n-192),rats of postnatal 14 days (P14,n=192),rats of postnatal 21 days (P21,n=192) and rats of postnatal 28 days (P28,n=192),were equally randomized into vehicle group (n=96) and control group (n-96),respectively; SE rat models of the vehicle group were induced by intraperitoneal injection of 1％ PTZ (80 mg/kg); and rats of the control group were received injection of normal saline (NS); 6 and 12 h,and 1,2,3 and 7 d after the inducement,the mRNA and protein expressions of HIF-1α in the hippocampus of rats in these 8 groups were examined by RT-PCR and immunohistochemistry, respectively. Another 48 21-d- old SD rats were equally randomized into vehicle I group (n=24) and intervention group (n=24); and rats in the intervention group received injection of HIF-lα antisense oligodeoxynucleotides (ASODN) into the right hippocampus and NS into the left hippocampus; 6 h after the injection,these 48 rats were induced into SE models by intraperitoneal injection of 1％ PTZ (80 mg/kg); 2 d after the inducement, the mRNA expression of HIF-1α in the hippocampus was examined by RT-PCR; and 7 and 14 d after theinducement, the protein expressions of HIF-1α and nestin in the hippocampus were examined by immunohistochemistry. Results The mRNA expression of HIF-1 α in the hippocampus of all the rats in the vehicle group after SE increased significantly with similar trend.Six h after SE,the HIF-1α mRNA expression significantly decreased with time prolongation (P＜0.05). Major HIF-1α positive cells were located in different areas at different time after SE. In intervention experiment, the HIF-1α mRNA expression 2 d after SE and the number ofnestin positive cells 7 and 14 d after SE in the vehicle I group and the left hippocampus of intervention group(being intervented with ASODN) obviously decreased as compared with those in the right hippocampus (being intervented with NS,P＜0.05). Conclusion The mRNA and protein expressions of HIF-1α in the hippocampus of developing rats are enhanced after SE with a correlation of age-in-days; correlativity between HIF-1α and proliferation of NSCs might exist after SE.

Effect of extract of Ginkgo bilob on learning and memory, neuron apoptosis and neurogenesis of juvenile rats with kindled seizure / 中华神经医学杂志

Objective To study the effect of extract of Ginkgo bilob (EGb) on learning and memory,nerve cell apoptosis and neurogenesis of juvenile rats with kindled seizure.Methods Two hundred and forty 21-d old SD rats were equally randomized into normal saline group (NS),kindled control for 7 d group (P-A7),kindled control for 14 d group (P-A14),EGb treatment for 7 d group (P-E7),EGb treatment for 14 d group (P-E14).All the rats,except rats of the NS group,were induced chronic kindling seizure by pentylenetetrazol.Morris maze test was used to detect the learning and memory abilities.Immunohistochemical staining was used to observe the nerve cell apoptosis and neural stem cell proliferation and differentiation in the hippocampus.BrdU/NeuN or BrdU/GFAP double-labeled staining was employed to observe the nerve cell differentiation.Results (1) The escape latency in Morris maze test in rats of every group was gradually shorted during 4 days of pre-treatment; the escape latency was (31.72±8.37) in P-E7 group and (31.29±4.35) in P-E14 group,which was significantly shorten than that in NS group (18.93±6.40),P-A7 group (47.86±9.14) and P-A14 group (44.79±7.72) (P＜0.05); the time in target quadrant in maze test showed gradual increase in rats of the NS,P-A7 and P-A14 groups and was significantly increased in rats of the P-E7 and P-E14 groups after EGb treatment (P＜0.05); the cross-platform times of rats in the P-A7 and P-A14 groups (4.38±1.06,4.50±0.93) in maze test were significantly shorter than those of NS rats (11.13±0.99),P-E7 rats (10.00±2.00) and P-E14 rats (10.63±0.92,P＜0.05).(2) TUNEL-positive cells in CA3 area ofhippocampus in rats of the NS group were obviously fewer than those in the other 4 groups (P＜0.05).The number of apoptotic cells in P-E7 and P-E 14 groups was (28.25±4.65) and (28.13±6.08),which was significantly reduced as compared with that in the P-A7 and P-A14 groups (P＜0.05).(3) Nestin-positive cells in the hippocampal CA1,CA3 and DG regions of rats from the NS group were fewer than those in the other 4 groups (P＜0.05); those in the P-E7 and P-E14 groups enjoyed the highest levels.(4) The number of BrdU/NeuN cells after EGb treatment was significantly larger than that before EGb treatment,and BrdU/NeuN-positive cells percentage in P-E14 group was higher than that in P-E7 group (P＜0.05),meanwhile,the co-expression ofBrdU/GFAP was about 4％-5％ after EGb treatment.Conclusion EGb can significantly improve the learning and memory abilities in young rats with kindled seizure; anti-apoptosis and promoted neural stem cell proliferation and differentiation effect of EGb might be the mechanism.

Effect of extracts of Ginkgo biloba leaf on learning-memory ability and NMDA receptor 1 expression in the hippocampus in rats with kindling-induced epilepsy / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effect of extracts of Ginkgo biloba leaf (EGb), a catalyzer of central nervous system, on learning-memory ability and possible mechanism in rats with kindling-induced epilepsy.</p><p><b>METHODS</b>Forty postnatal day 21 (P21) and 40 postnatal day 35 (P35) Sprague-Dawley (SD) rats were randomly respectively assigned to five groups: normal sodium (NS) control, kindling epilepsy model, high, middle and low dosage of EGb-treated kindling epilepsy. The kindling epilepsy model was established by an intraperitoneal injection of pentetrazole (PTZ). The learning-memory ability and NMDA receptor 1 (NMDAR1) expression in the hippocampus were measured by Y-maze test and immunohistochemistry assay respectively.</p><p><b>RESULTS</b>The stimulation times for reaching to academic standard in the Y-maze test in the two ages PTZ kindling groups was significantly more than that in the corresponding NS control groups (P<0.01). After EGb treatment the achievement of the Y-maze test in the three treatment groups was significantly improved in a dose-dependent manner, the higher the dosage, the better the achievement (P<0.01). Immunohistochemistry assay showed that the expression of NMDAR1 in the two ages PTZ kindling groups was significantly higher than that in the corresponding NS control groups (P<0.01). Compared with the corresponding untreated kindling model groups, the expression of NMDAR1 in the two ages EGb treatment groups was significantly reduced in a dose-dependent manner (P<0.01).</p><p><b>CONCLUSIONS</b>EGb can improve learning-memory ability in epileptic rats at different developmental phases in a dose-dependent manner, possibly through a reduction of NMDAR1 expression in the hippocampus.</p>

Neurogenesis of hippocampus following pentylenetrazol-induced status epilepticus in developing rats and the effect of MK-801 on neurogenesis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study aimed to determine whether pentylenetetrazol-induced status epilepticus (SE) can induce dentate granule cell neurogenesis in the developing rat and the effect of MK-801, a noncompetitive antagonism of N-methyl-D-aspartate receptor (NMDAR), on neurogenesis.</p><p><b>METHODS</b>Two hundred and sixteen postnatal days 7, 14, 21 or 28 Sprague Dawley (SD) rats were involved in this study. Each age group consisted of 54 rats which were randomly assigned into a SE group, a SE + MK-801 group and a Normal control group (n=18 each). SE was induced by intraperitoneal injection of PTZ (80 mg/kg). The SE + MK-801 group was injected intraperitoneally with MK-801 (1 mg/kg) at 1 hr after SE episode. All rats were given 5-bromodeoxyuridene (BrdU) intraperitonealy to label newborn cells at 6, 13 and 27 days after seizures and then were sacrificed 24 hrs after BrdU injection. The immunohistochemistry method was used to measure the expression of BrdU, TuJl (betaIII tubulin), and glial fibrillary acidic protein (GFAP) in the dentate gyrus of hippocampus of rats.</p><p><b>RESULTS</b>The number of the BrdU positive cells in the SE group was significantly higher than in the age-matched normal controls at 7 and 14 days after SE episode (P <0.05 or 0.01). Approximately 82.5% and 80.3% of BrdU-labeled cells in the SE and the Control groups were co-expressed TuJ1 respectively. MK-801 treatment decreased the BrdU positive cells compared with the SE group at 7 and 14 days after SE seizures (P < 0.01). On the 28th day after SE episode there were no differences among the three groups for the BrdU positive cells.</p><p><b>CONCLUSIONS</b>PTZ-induced SE can increase the dentate granule cell neurogenesis in the developing rat. NMDAR plays an important role in neurogenesis following seizures.</p>

Effect of c-fos Antisense on Neuronal Apoptosis in Rats′ Brain with Pentyleneterazol-Induced Seizure / 实用儿科临床杂志

Objective To probe the effect of c-fos gene on the pentyleneterazol-induced hippocampal neurons apoptosis.Methods Using immunohistochemistry,TUNEL and flow cytometry(FCM),we detected the Fos expression and the apoptosis of hippocampal neurons;we injected c-fos antisense into ventrile before epilepsy and detected as up.Results Epilepsy can induce the expression of Fos in the hippocampus and peaking at 1 h(P

Relationship between Infantal Epilepsy and Human Cytomegalovirus Infection / 实用儿科临床杂志

Objective To explore the relationship of human cytomegalovirus(HCMV) infection and infantal epilepsy.Methods Fluorescence quantitative polymerase chain reaction was employed to detect the urine HCMV-DNA in 20 healthy children and 52 infants with epilepsy,and the changes in head CT scanning and brainstem auditory evoked potential were determined in HCMV positive and negative epilepsy infants.Results Positive HCMV-DNA was found in 31(59.62%)infants with epilepsy and 6(30%)healthy infants,there was significant difference between two groups(P

Exploration and practice of bilingual teaching in pediatrics of the undergraduates / 中华医学教育探索杂志

To further explore the result of bilingual teaching in pediatrics,we randomly chose 200 undergraduates of 4 class and released students'questionnaires about bilingual teaching with teaching content before and after class to assess students'understanding of bilingual teaching and analysed appraisal result.We found no significant difference of student score between students accepting bilingual teaching and not accepting the bilingual teaching,but there was difference for English tests and expression level.So we think that students can fully accept the bilingual teaching of pediatrics under the premise with selecting appropriate teaching methods and means.

Clinical Significance of P- Selectin Expression in Children with Viral Encephalitis / 实用儿科临床杂志

Objective To study the clinical significance of P - selection expression in children with viral encephalitis and the correlation between this expression and the cerebral infarction with critical viral encephalitis. Methods Flow cytometric was employed to detect the expression of P- selection on the surface of platelet membrane in 44 children with viral encephalitis(20 light patients and 24 critical patients) and 20 healthy control children. The area of the cerebral infarction was determined by computed tomographic scan in 20 patients with critical viral encephalitis. The correlation between the two variables was analyzed. Results The expressions of P - selection on the surface of platelet membrane on less than 5 days and on 2 weeks after the onset of viral encephalitis were significantly higher in critical patients than those in normal control children and light patients( P

Study on Hippocampus Neurogenesis in Rats with Different Ages / 实用儿科临床杂志

Objective To explore the effect of age on neurogenesis of dentate gyrus granule cell and the impact on differentiation of newborn cells in rats.Methods SD rats were selected and divided into 5 groups according age of 7,14,28,60,180 d(n=8),and the neurogenesis of dentate gyrus granule cell in hippocampus with normal development was detected,using 5-bromo-BrdU(BrdU) labled newborn neuron and ?-tubulin protein(TuJ1) and glial fibrillary acidic protein(GFAP) labeled glial cells,and understood the newborn cells to neurons and glial cell differentiation ratio.Results Neurogenesis was found in dentate gyrus granule cell layer with hippocampus of all different age rats.Various forms of cells with a larger nucleus that were round,oval,diamond were distributed over the entire granule cell layer.BrdU-positive cells within each group were 158.07?5.37,141.28?7.27,116.93?9.24,76.56?6.88,41.42?4.45,the number of BrdU-positive cells were reduced with the growth of rats(P0.05);4%-5% newborn cells expressed GFAP.In addition,some of the BrdU-positive cells at the same time did not express TuJ1 or GFAP.Conclusions There are neurogenesis in dentate gyrus granule cell in rats of different age.The new born cells mostly differentzate into granule neuron cell.The capability of cell proliferation are decreased with the growth of age.