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Objective T o observe the changes of cystathionine β-synthase (C B S ) expression in the cere-bral cortex after brain contusion at different tim es. Methods A n experim ental m odel of traum atic brain injury (T B I) in m ice w as established by an im proved w eight-drop device. T hen W estern blotting and im m unohistochem ical exam ination w ere used to detect the C B S expression in cerebral cortex around in-jury at different tim e points (1 h, 6 h, 12 h, 1 d, 2 d, 3 d, 7 d). Results T he results of W estern blotting revealed that the expression level of C B S w as dow n-regulated and reached its low est level at the 3rd days after injury, and then restored to norm al level after 7 days. T he results of im m unohistochem istry show ed that C B S w as present in the norm al brain cortex. C B S expression gradually decreased at the 3rd days after injury, and then restored to norm al level after 7 days. Conclusion C B S has the potential to be a reference index for tim e estim ation after brain contusion in forensic practice.
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Objective T o explore the com position characteristic of event related potential (E R P ) in dif-ferent visual acuity levels, and to provide theoretical basis for the objective assessm ent of visual acuity. Methods M onocular stim ulus w as perform ed on 16 selected subjects. T he subjects w ere required to look straight at the screen ahead and count the am ount of stim uli from different directions. T he pictures of optotype stim ulus w hich corresponding to three different visual acuity levels w ere show ed in the center of the screen. The ERP results w ere recorded separately. Results (1) The P1 am plitudes of m atch stim uli recorded under the supra-threshold visual acuity level w ere higher than that of m atch stim uli recorded under the threshold and sub-threshold visual acuity levels. T here w as no significant difference betw een the P 1 am plitudes of m atch stim uli recorded under the threshold and sub-threshold visual acuity levels. T he tendency of conflict stim uli w as sim ilar to that of m atch stim uli under three visual acuity levels. (2) In the 340-500 m s post-stim ulus range, P 300 com ponent w as found under supra-threshold and threshold visual acuity levels; no P 300 com ponent w as found in corresponding tim e w indow under sub-threshold visual acuity. T he differences of P 300 am plitudes am ong three visual acuity levels w ere statistically significant. T he am plitudes from high to low w ere the supra-threshold, threshold and sub-threshold visual acuity levels. Conclusion E R P can be a potential new m ethod for the objective assessm ent of visual acuity in forensic m edicine.
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Objective T o study the effect of different attentional conditions on the event-related potential (E R P ) com ponents generated by the visual inform ation stim uli related to visual acuity, and provide a theoretical reference for clinical forensic visual objective evaluation. Methods W ith visual acuity opto-types as norm al form of visual inform ation stim uli, 15 volunteers as study subjects w ere supposed to ac-count the visual acuity optotypes under the attentional condition of visual stim uli. Furtherm ore, the sub-jects w ere required to listen to the storytelling carefully under the non-attentional condition of visual stim uli, and after the exam ination, they needed to answ er the story-related questions. A ll the E E G re-sults of tw o different attentional conditions from the subjects w ere recorded by 32 channel E R P system . Results U nder tw o attentional conditions, P 1 and P 300 com ponents w ere evoked by the visual acuity opto-types on supra-threshold and threshold visual acuity levels, w hile only P 1 com ponent w ere evoked by the visual acuity optotypes on sub-threshold levels. In the E R P w aveform s evoked by the visual acuity optotypes on supra-threshold, P 1 and P 300 am plitudes under attentional condition w ere larger than that un-der non-attentional condition. Conclusion A ttentional conditions can influence the detection of visual acuity. P 300 com ponent can be used to distinguish the visual acuity levels w ith supra-threshold and sub-threshold under non-attentional condition.
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Mild cognitive im pairm ent caused by craniocerebral traum a is the key points and difficulties in judicial authentication. This article has com parative analysis of eachmode of event-related potential (classical O ddball, E riksen flanker task and so on), which can provide a more objective m ethod for such craniocerebral traum a cases in clinical forensic judicial authentication.
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Objective To observe the time-course expression of zonula occludens-1 (ZO-1) in cerebral cortex after traumatic brain injury (TBI). Methods The TBI model of mouse was established. The mice were divided in 1 h, 3 h, 6 h, 12 h, 24 h, 3 d, 7 d after TBI, shamand control groups. The permeability of the blood brain barrier was evaluated by measuring the extravasation of Evans blue (EB) dye. The expression of Z O-1 in cerebral cortex in the injured area was detected by western blotting and im-munohistochemistry. Results The extravasation of EBdye of injured cortex gradually increased from 1 h, peaked at 1-3 d and approximately decreased to normal at 7 d after TBI. western blotting revealed that the expression of Z O-1 gradually decreased after 1 h, was at the lowest at 1-3 d, and then significantly increased after 7 d but was still lower than that of normal and shamgroups. The result of immunohisto-chemistry showed that Z O-1 had strong expression in vessel of normal cortex, gradually decreased after TBI, and almost disappeared at 3 d after TBI and gradually recovered to normal level later. Conclusion The expression of Z O-1 in the injured cortex after TBI initially decreases and then increases. The nega-tive correlation between Z O-1 expression and EBextravasation after TBI could be used as a newindi-cator for wound age estimation.
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Objective To observe the time-course expression of calcium-calmodulin dependent protein ki-naseⅡδ (CaMKⅡδ) in cerebral cortex after traumatic brain injury (TBI). Methods The TBI rat model was established. The expression of CaMKⅡδ in cerebral cortex around injured area was tested by Western blotting and immunohistochemical staining . Results Western blotting revealed expression of CaMKⅡδ in normal rat brain cortex. It gradually increased after TBI, peaked after 3 days, and then returned to normal level. The result of immunohistochemical staining was consistent with that of West-ern blotting. Conclusion The expression of CaMKⅡδ around injured area after TBI increased initially and then decreased. It could be used as a new indicator for wound age determination following TBI.
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Objective To explore the repetitive expressions of autophagy marker protein-rnicrotubule-associ-ated protein 1 light chain 3 (LC3) in hippocampus in newborn rats with recurrent seizure and the influence of 3-methyladeine (3-MA) on LC2 expressions. Method Seventy-two 6-day-old SD rats were randomly (random nam-ber) divided into the recurrent neonatal seizure group (RS group, n = 24), the 3-MA-treated seizure group (3-MA group, n = 24) and control group (n = 24). Rats in RS group were subjected to 55 attacks of seizure induced by flurothyl in 9 successive days from the 6th postnatal day (P6). In 3-MA group, 2 μL of 3-MA was injected every day till seizure induced. Western blot analysis was used to determine LC3 protein level in hippocampus at different intervals of 1.5 h,3 h,6 h and 24 h after the last convulsion. The LC3 protein level was analyzed with Dunnett test after ANOVA. Results LC3 protein levels in RS group at the different intervals were significantly higher than those in the control group and in 3-MA group (F =4.70,5.28,8.51 and 5.89, respectively, P <0.05), and there were no significant differences in LC3 protein level between 3-MA group and control group at those intervals (P > 0.05). Conclusions The autophagy/lysosomal pathway is immediately activated after recurrent seizure evidenced by the elevated expressions of LC3 in hippocampus. The 3-MA is involved in the regulation of autophagy/ lysosomal pathway by down-regulating the expressions of LC3.
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Objective To explore the effects of physical exercises on recurrent seizures-induced long-term learning and memory deficits and on the expression of zinc transporter-3(ZnT-3)in hippocampuses of developmental period rats.Methods Sprague-Dawley rats aged 21 d were randomly divided into blank control group,exercises control group,seizure group and seizure plus exercises group.Abdominal cavity injections of penicillin or saline were used to induce recurrent seizure or as a control in the corresponding groups.During the postnatal(P)39-44 d and P61-65 d periods,Morris water-maze tests were administered to evaluate spatial learning and memory capacity.During the P48-53 d period,the rats in exercises control and seizure plus exercises groups were subjected to a 30-min daily aerobic exercises program for 6 d.The real-time reverse transcription-polymerase chain reaction(RT-PCR)method was used to detect the expression of ZuT-3 mRNA in hippocampuses of all rats at P66 d. Results Searching strategy:There was a decreasing incidence of marginal strategy and an increasing trend in the use of taxis and straight line strategy in all four groups.The scores on d 1 and 4 were significantly higher in two control groups than in two seizure groups in water-maze test(all P＜0.05).By d 2 the exercises control and seizure plus exercises groups were scoring significantly higher than the bland control and seizure groups(P＜0.05).Memory test:The frequency of passing through the platform quadrant decreased significantly in the two seizure groups compared to the two control groups in both probe tests(all P＜0.05).RT-PCR test:ZnT-3 mRNA expressions in hippocampuses were significantly higher in seizure plus exercises group than in any other groups. Conclusions Penicillin-induced recurrent seizures can induce long-term damage on learning and memory capacity in developmerital period rats.Physical exercises can improve learning capacity.It's mechanism may be related to the up-regulation of ZnT-3 expression in hippocampus of rats.
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Despite the clinical and experimental concerns about the deleterious effects of neonatal seizures on brain development,the underlying mechanism of seizure-induced brain damage is still not clear.Moreover,early therapeutic intervention studies are also less available.For this reason,the study was performed to explore the long-term effects of neonatal seizures and physical exercise on learning,memory and the expression of calcium/calmodulin-dependent protein kinase Ⅱ(CaMKⅡ).Twelve neonatal rats for each group were assigned:the single-seizure group(SS),the recurrent-seizure group(RS) and the control group.The volatile agent flurothyl was used to induce 30 min seizure attack.At postnatal day 6(P6),the single seizures induced only once and recurrent seizures induced once per day for consecutive 6 days.Control rats were placed into the container for an equal amount of time to their counterpart without exposure to flurothyl.Morris water-maze test were performed at P27～P31,P58～P61 and P80～P82,meanwhile at P51～P56,the RS and SS groups were submitted to forced running exercise.In situ hybridization method was used to detect the expression of CaMKⅡ mRNA in hippocampus.The results are as follows:(1) Escape latency.In the first two Morris water-maze tests,there was a decreasing trend of escape latency in three groups,and the escape latency of RS group was much longer than that of control group.After physical exercise,in the last Morris water-maze tests,the diference of escape latency in three groups is not significant.(2) Searching strategy.In the first Morris water-maze test,there was a decreasing trend of marginal strategy and an increasing trend of taxis strategy in three groups,but the frequency of marginal strategy was higher and the frequency of taxis strategy was lower in RS group than that in SS and control group in the third and fourth day(P
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Objective To investigate the expression of caspase-3 in different post-traumatic intervals and severity of traumatic brain injury (TBI). Method Brain tissue samples of slight (n =24), moderate (n = 24) brain injury and control (n = 10) groups of rat were examined by immunohistochemical staining. Results Up-regulation of caspase-3 expression was found in tissues from traumatic brain injury as compared with controls in 1h after TBI, and lasted for 2 weeks. In tissues taken Ih, 12h, 24h, 72h, lweek and 2weeks after TBI there were different amount of positive celis in brain injuries of different severity. Con-clusion The expression of caspase-3 is different in brain injuries of different severity . These findings are valuable in appraising the severity of injuries.