Objective To investigate the impact of AG490 on the blood-brain barrier (BBB ) permeability and the expression of interleukin-6 (IL-6 )and tumor necrosis factor-α(TNF-α)after traumatic brain injury (TBI)in rats. Methods A total of 144 healthy male SD rats were randomly divided into a control group,a trauma group,and an AG490 intervention group (n=48 in each group). The rats in each group were redivided into four subgroups (4 h,1 d,3 d,and 7 d subgroups)according to the time points after cerebral injury (n=12 in each subgroup). A brain trauma models were induced by hydraulic shock method. Evans blue was used to determine the changes of the BBB permeability after cerebral injury in each group. Real-time fluorescence quantitative PCR was to detect the expression levels of TNF-αand IL-6 mRNA in rat brain tissue. Immunohistochemistry was used to detect the expression of human phospho tyrosine kinase (P-JAK2). Results (1)The permeability of BBB:The permeability of BBB increased at 4 h,1 d,3 d and 7 d after brain injury in the trauma group (Evans blue permeation:10. 4 ± 1. 2,16. 0 ± 1. 4,22. 3 ± 2. 0,and 8. 4 ± 0. 9μg/g,respectively). Compared with the control group, there were significant differences (all P<0. 01). The Evans blue permeation of the AG490 intervention group were 9. 1 ± 1. 0,12. 8 ± 1. 1,17. 5 ± 1. 4 and 7. 1 ± 0. 8μg/g,respectively at each time point,and they were all significantly lower than those of the trauma group (all P<0. 01). (2)The expression of IL-6 and TNF-α mRNA:The expression levels of IL-6 mRNA and TNF-α mRNA at 4 h,1 d,3 d and 7 d after traumatic brain injury in the trauma group were 2. 31 ± 0. 35,2. 73 ± 0. 35,3. 32 ± 0. 29,2. 14 ± 0. 24 and 7. 46 ± 1. 18,9. 42 ± 1. 54,13. 76 ± 1. 89,and 6. 28 ± 1. 00,respectively,they were all significantly higher than those of the control group (all P<0. 01). The expression levels of IL-6 mRNA and TNF-α mRNA of the AG490 intervention group were 1. 14 ± 0. 22,1. 54 ± 0. 23,1. 94 ± 0. 32,1. 26 ± 0. 21 and 5. 57 ± 0. 88, 7. 78 ± 1. 02,11. 51 ± 1. 29,and 5. 05 ± 0. 97,respectively,they were all lower than those of the trauma group,but they still higher than the control group. There were significant differences (all P<0. 01). (3 )The expression of P-JAK2:The expression levels of P-JAK2-positive cells at each time point after traumatic brain injury in the trauma group were significantly higher than the control group (all P<0. 01),they were 17. 4 ± 2. 7,56. 2 ± 6. 7,26. 1 ± 5. 4,and 15. 3 ± 2. 5,respectively;those of the AG490 intervention group were 12. 2 ± 1. 4,41. 5 ± 4. 6,19. 4 ± 4. 1,and 9. 6 ± 2. 0,respectively,they were all lower than those of the trauma group,but still higher than the control group. There were significant differences (all P<0. 01). Conclusion During the acute phase after TBI,AG490 may activate the factor signaling pathways by inhibiting the non-receptor tyrosine kinase/signal transduction and transcription,significantly inhibit the expression of brain tissue inflammatory cytokines IL-6 IL-6 and TNF-α,reduce the BBB damage,and help to reduce secondary brain injury.

Objective:To explore the effects and possible mechanisms of melatonin combined with enriched environment on the learning and memory ability of senescence-accelerated mouse prone 8(SAMP8).Methods:Forty-eight SAMP8 male mice aged 4 months were randomly divided into model group, enriched environment group, melatonin group and melatonin combined with enriched environment group (combined intervention group) by random number table method, with 12 mice in each group. Mice in the melatonin group and combined intervention group were subcutaneously injected with melatonin at a dose of 8 mg·kg -1·d -1, and the mice in the model group and the enriched environment group were given the same amount of normal saline instead.The mice in model group and melatonin group were raised in a standard environment, and the mice in enriched environment group and combined intervention group were raised in an enriched environment.The intervention lasted 28 days. The aging degree of mice was scored before and 28 days after the intervention. Morris water maze test was used to detect the learning and memory ability of mice. Nissl staining and TUNEL staining were used to observe the Nissl staining positive cells and apoptotic cells in the CA1 area of hippocampus.ELISA was used to detect the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the hippocampus of mice. Western blot was used to detect the levels of amyloid β-protein (Aβ) 1-42, microtubule-associated protein tau (tau) phosphorylated at threonine (Thr) 205 (Tau pT205), Toll-like receptor 4 (TLR4), and nuclear factor-κB (NF-κB) p65 protein in the hippocampus of mice. qRT-PCR was used to detect the levels of TLR4, NF-κB p65 mRNA in the hippocampus of mice. SPSS 22. 0 statistical software was used for repeated measure ANOVA, one-way ANOVA and LSD test. Results:(1) Aging score: after intervention, the aging scores of mice in the four groups were significantly different ( F=120.601, P<0.01). The aging scores of mice in the enriched environment group, melatonin group, and combined intervention group were lower than those in the model group (all P<0.05), while the aging score of mice in the combined intervention group was significantly lower than those in the enriched environment group and melatonin group (both P<0.05). (2) The results of the location navigation experiment showed that the time × group interaction effect of the escape latencies of mice in the four groups were significant ( F=30.524, P<0.001). From the 2nd to 4th day, the escape latencies of mice in the enriched environment group, melatonin group and combined intervention group were all lower than that in the model group (all P<0.05). The results of the space exploration experiment showed that the residence time in the target quadrant and the number of platform crossings of mice in the four groups were significantly different ( F=291.328, 113.482, both P<0.01). The residence time in the target quadrant ((29.45±1.70)s, (32.44±1.55)s, (37.48±0.84) s) and the number of platform crossings ((6.44±0.61) times, (7.16±0.70) times, (12.60±1.23) times) of mice in the enriched environment group, melatonin group and combined intervention group were higher than those in the model group ((15.07±1.28) s, (4.10±0.61) times), while the residence time in the target quadrant and the number of platform crossings of mice in the enriched environment group and the melatonin group were significantly lower than those in the combined intervention group (all P<0.05). (3) Nissl and TUNEL staining showed that the number of Nissl positive neurons in the hippocampal CA1 region of mice in the four groups were significantly different ( F=809.264, P<0.01), and the number of apoptotic cells in the hippocampal CA1 region were also significantly different ( F=1 060.583, P<0.01). The number of Nissl stained positive neurons in the hippocampal CA1 region of mice in the combined intervention group was more than those in the model group, enriched environment group, and melatonin group (all P<0.05), and the number of apoptotic cells were less than those in the model group, enriched environment group, and melatonin group (all P<0.05). (4) The results of ELISA assay showed that there were significantly different in the levels of IL-1β, IL-6 and TNF-α in the hippocampus of mice in the four groups ( F=152.887, 63.506, 432.026, all P<0.01). The contents of IL-1β, IL-6 and TNF-α in the hippocampus of mice in the enriched environment group, melatonin group, and combined intervention group were lower than those in the model group(all P<0.05). Among them, the contents of IL-1β, IL-6 and TNF-α in the hippocampus of mice in the enriched environment group and melatonin group were significantly higher than those in the combined intervention group (all P<0.05). (5) Western blot analysis showed that there were significantly different in the protein expression levels of Aβ1~42, tau pT205, TLR4, NF-κB p65 in the hippocampus of mice in the four groups ( F=122.349, 98.934, 201.635, 116.553, all P<0.01). The protein expression levels of Aβ1-42, tau pT205, TLR4, and NF-κB p65 in the hippocampus of mice in the enriched environment group, melatonin group, and combined intervention group were lower than those in the model group.Among them, the protein expression levels of Aβ1-42, tau pT205, TLR4, NF-κB p65 in the hippocampus of mice in the enriched environment group and melatonin group were significantly higher than those in the combined intervention group (all P<0.05). (6) qRT-PCR showed that the mRNA expression levels of TLR4 and NF-κB p65 in the hippocampus of mice in the four groups were significantly different ( F=42.913, 102.446, both P<0.01). The mRNA expression levels of TLR4 ((0.63±0.05), (0.55±0.04), (0.42±0.03)) and NF-κB p65 ((0.98±0.06), (0.82±0.04), (0.72±0.04)) in the hippocampus of mice in the enriched environment group, melatonin group and combined intervention group were lower than those in the model group ((0.74±0.07), (1.20±0.05)) (all P<0.05). Among them, the mRNA expression levels of TLR4 and NF-κB p65 in the hippocampus of mice in the enriched environment group and melatonin group were significantly higher than those in the combined intervention group (all P<0.05). Conclusion:Melatonin combined with enriched environment can improve the learning and memory ability and neuroinflammatory response of SAMP8 mice, and its mechanism may be related with the down-regulation of TLR4/NF-κB p65 signaling pathway.

Objective To investigate the effectiveness of evoked potential in monitoring cerebral perfusion during carotid endarterectomy by a retrospective cohort study.Methods A retrospective cohort survey of clinical data of 59 patients,who underwent carotid endarterectomy in our hospital from September 2013 to December 2016,was performed.All patients were monitored by transcranial doppler ultrasonography (TCD) and somatosensory evoked potential (SEP),motor evoked potential (MEP) for changes of cerebral blood flow;the monitoring of TCD was defaulted as "gold standard",recording monitoring results at different time points.By drawing the four table,the sensitivity,specificity,positive predictive value,negative predictive value of SEP and MEP during cerebral hypoperfusion were calculated,and correlation analyses between SEP and TCD,and between MEP and TCD were performed.Through receiver operating characteristic (ROC) curve,SEP monitoring threshold of cerebral hypoperfusion was predicted.Results The sensitivity,specificity,positive predictive value,and negative predictive value of SEP in predicting intra-operative cerebral hypoperfusion were 60.00％,91.84％,60.00％,and 91.84％ when SEP amplitude declined beyond 50％;the sensitivity,specificity,positive predictive value and negative predictive value of SEP in predicting intra-operative cerebral hypoperfusion were 70.00％,93.88％,70.00％ and 93.88％ when SEP latency extended beyond 10％.The sensitivity,specificity,positive predictive value,and negative predictive value of MEP in predicting intra-operative cerebral hypoperfusion were 30.00％,97.96％,75.00％,and 87.27％ when MEP amplitude declined beyond 50％.Decline of SEP and MEP amplitudes and extension of SEP latency have positive correlations with TCD.ROC indicated that the amplitude of somatosensory evoked potentials could predict intraoperative hypoperfusion when it decreased by 51.0％ than the baseline monitoring value after carotid artery occlusion,with sensitivity of 100.0％,specificity of 89.8％ and area under the curve of 0.918 (95％CI:0.846～0.990,P=0.024).ROC also showed that the latent phase of somatosensory evoked potentials could predict intraoperative hypoperfusion when it was prolonged ＞9.8％ compared to the baseline monitoring value after carotid artery occlusion,with sensitivity of 100.0％,specificity of 92.9％and area under the curve of 0.941 (95％CI 0.878～0.995,P=0.014).Conclusion Evoked potentials can real-time monitor intra-operative cerebral hypoperfusion continuously in carotid endarterectomy,enjoying high sensitivity and specificity;in addition,decline of SEP amplitude and extension of SEP latency have higher sensitivity than MEP.