Characteristics of Visual Evoked Potential in Different Parts of Visual Impairment / 法医学杂志

OBJECTIVES@#To study the quantitative and qualitative differences of visual evoked potential (VEP) in monocular visual impairment after different parts of visual pathway injury.@*METHODS@#A total of 91 subjects with monocular visual impairment caused by trauma were selected and divided into intraocular refractive media-injury group (eyeball injury group for short), optic nerve injury group, central nervous system injury and intracranial combined injury group according to the injury cause and anatomical segment. Pattern Reversal visual evoked potential (PR-VEP) P100 peak time and amplitude, Flash visual evoked potential (F-VEP) P2 peak time and amplitude were recorded respectively. SPSS 26.0 software was used to analyze the differences of quantitative (peak time and amplitude) and qualitative indexes (spatial frequency sweep-VEP acuity threshold, and abnormal waveform category and frequency) of the four groups.@*RESULTS@#Compared with healthy eyes, the PR-VEP P100 waveforms of the intraocular eyeball injury group and the F-VEP P2 waveforms of the optic nerve group showed significant differences in prolonged peak time and decreased amplitude in injured eyes (P<0.05). The PR-VEP amplitudes of healthy eyes were lower than those of injured eyes at multiple spatial frequencies in central nervous system injury group and intracranial combined injury group (P<0.05).The amplitude of PR-VEP in patients with visual impairment involving central injury was lower than that in patients with eye injury at multiple spatial frequencies. The frequency of VEP P waveforms reaching the threshold of the intraocular injury group and the optic nerve injury group were siginificantly different from the intracranial combined injury group, respectively(P<0.008 3), and the frequency of abnormal reduction of VEP amplitude of threshold were significantly different from the central nervous system injury group, respectively(P<0.008 3).@*CONCLUSIONS@#VEP can distinguish central injury from peripheral injury, eyeball injury from nerve injury in peripheral injury, but cannot distinguish simple intracranial injury from complex injury, which provides basic data and basis for further research on the location of visual impairment injury.

Effect of Different Attentional Conditions on ERP Detection of Visual Acuity / 法医学杂志

OBJECTIVES@#To study the effect of different attentional conditions on the event-related potential （ERP） components generated by the visual information stimuli related to visual acuity, and provide a theoretical reference for clinical forensic visual objective evaluation.@*METHODS@#With visual acuity optotypes as normal form of visual information stimuli, 15 volunteers as study subjects were supposed to account the visual acuity optotypes under the attentional condition of visual stimuli. Furthermore, the subjects were required to listen to the storytelling carefully under the non-attentional condition of visual stimuli, and after the examination, they needed to answer the story-related questions. All the EEG results of two different attentional conditions from the subjects were recorded by 32 channel ERP system.@*RESULTS@#Under two attentional conditions, P₁ and P₃₀₀ components were evoked by the visual acuity optotypes on supra-threshold and threshold visual acuity levels, while only P₁ component were evoked by the visual acuity optotypes on sub-threshold levels. In the ERP waveforms evoked by the visual acuity optotypes on supra-threshold, P₁ and P₃₀₀ amplitudes under attentional condition were larger than that under non-attentional condition.@*CONCLUSIONS@#Attentional conditions can influence the detection of visual acuity. P₃₀₀ component can be used to distinguish the visual acuity levels with supra-threshold and sub-threshold under non-attentional condition.

Forensic Application of Objective Assessment on Visual Acuity by ERP / 法医学杂志

OBJECTIVES@#To explore the composition characteristic of event related potential （ERP） in different visual acuity levels, and to provide theoretical basis for the objective assessment of visual acuity.@*METHODS@#Monocular stimulus was performed on 16 selected subjects. The subjects were required to look straight at the screen ahead and count the amount of stimuli from different directions. The pictures of optotype stimulus which corresponding to three different visual acuity levels were showed in the center of the screen. The ERP results were recorded separately.@*RESULTS@#（1） The P₁ amplitudes of match stimuli recorded under the supra-threshold visual acuity level were higher than that of match stimuli recorded under the threshold and sub-threshold visual acuity levels. There was no significant difference between the P₁ amplitudes of match stimuli recorded under the threshold and sub-threshold visual acuity levels. The tendency of conflict stimuli was similar to that of match stimuli under three visual acuity levels. （2） In the 340-500 ms post-stimulus range, P₃₀₀ component was found under supra-threshold and threshold visual acuity levels; no P₃₀₀ component was found in corresponding time window under sub-threshold visual acuity. The differences of P₃₀₀ amplitudes among three visual acuity levels were statistically significant. The amplitudes from high to low were the supra-threshold, threshold and sub-threshold visual acuity levels.@*CONCLUSIONS@#ERP can be a potential new method for the objective assessment of visual acuity in forensic medicine.

The Role of CBS in Injury Time Estimation after Brain Contusion / 法医学杂志

OBJECTIVES@#To observe the changes of cystathionine β-synthase （CBS） expression in the cerebral cortex after brain contusion at different times.@*METHODS@#An experimental model of traumatic brain injury （TBI） in mice was established by an improved weight-drop device. Then Western blotting and immunohistochemical examination were used to detect the CBS expression in cerebral cortex around injury at different time points （1 h, 6 h, 12 h, 1 d, 2 d, 3 d, 7 d）.@*RESULTS@#The results of Western blotting revealed that the expression level of CBS was down-regulated and reached its lowest level at the 3rd days after injury, and then restored to normal level after 7 days. The results of immunohistochemistry showed that CBS was present in the normal brain cortex. CBS expression gradually decreased at the 3rd days after injury, and then restored to normal level after 7 days.@*CONCLUSIONS@#CBS has the potential to be a reference index for time estimation after brain contusion in forensic practice.

Research Progress of Event-related Potential in Mild Cognitive Impairment / 法医学杂志

Mild cognitive impairment caused by craniocerebral trauma is the key points and difficulties in judicial authentication. This article has comparative analysis of each mode of event-related potential (classical Oddball, Eriksen flanker task and so on), which can provide a more objective method for such craniocerebral trauma cases in clinical forensic judicial authentication.

Correlation of daily living activities with location and severity of traumatic brain injury / 法医学杂志

OBJECTIVE@#To study the correlation of daily living activities with location and severity of trau- matic brain injury (TBI) and to provide a theoretical basis for improving the accuracy of expert opinion.@*METHODS@#Five hundred and one cases of patients with TBI were selected. Detailed records included following: pre-injury situation, location and severity of injury, treatment and education. Daily living activi- ties scale (Barthel index) was applied to test the subjects' daily living activities. The relevance among location and severity of TBI and Barthel index was statistically analyzed.@*RESULTS@#In mild TBI group, there was no significant difference in Barthel index among each location (P>0.05). In moderate TBI group, there were significant differences in Barthel index between subarachnoid hemorrhage and cerebral lobe injury, also between parietal, occipital lobes injury and frontal lobe injury, parietal, occipital lobes injury and temporal lobe (P<0.05), respectively, whereas no significant difference in Barthel index between frontal lobe injury and temporal lobe injury (P>0.05). In severe TBI, there were significant differences in Barthel index between every two different locations (P<0.05).@*CONCLUSION@#There is some correlation between the location of TBI and Barthel index, which provides an important reference value for analyzing and determining daily living activities after TBI.

Characteristics and distribution of ERP by different field stimulation / 法医学杂志

OBJECTIVE@#To study the variation of latency and amplitude of the event related potential (ERP) and its distribution in human scalp when the normal subjects were stimulated with different visual fields.@*METHODS@#The ERP recorded in scalp with the stimulation of 10 degrees visual field and 60 degrees visual field respectively in 20 healthy volunteers with normal visual function.@*RESULTS@#Two different visual field stimulation may evoke the different exogenous components P1 (70-125 ms), N1 (90-170 ms), P2 (140-220 ms) and endogenous components N2 (190-280 ms) and P3 (290-430 ms). The latencies of all the components evoked by 10 degrees visual field were shorter than that of the 60 degrees visual field while the amplitudes of N1 and N2 were lower and appeared over the extensive encephalic region; and the amplitudes of the P1, P2 and P3 were higher and appeared in occipitotemporal, prefrontal and occipital region, respectively.@*CONCLUSION@#Two different visual field stimulation may evoke all the ERP components with significant differences in the latency, amplitude and distribution. The differences may reflect the different visual information integration and processing in human brain during the different visual field stimulation.

Correlation of pattern reversal visual evoked potentials P100 with visual acuity / 法医学杂志

OBJECTIVE@#To explore pattern reversal visual evoked potential (PRVEP) P100 components in the patients with different visual acuity and the correlation of P100 components with visual acuity using different visual simulation angles.@*METHODS@#PRVEPs were recorded at Oz point in the patients (100 eyes) with different visual acuity including 0.2, 0.4, 0.6, 0.8 and 1.0 and induced by pattern reversal visual simulation with the different spatial frequencies(check sizes: 8 degrees-7.5'). The latency and amplitude of components P100 were analyzed and statistical analysis was performed using SPSS 13.0 software.@*RESULTS@#The latency and amplitude of P100 wave showed a curvilinear relationship with check sizes. With check size 10 simulation in 0.2 visual acuity group, the P100 latency reached to the minimum and the P100 amplitude showed peak value. Other groups displayed the best value with check size 30'. The P100 latency and amplitude showed a linear correlation with visual acuity. With the increase of visual acuity, the P100 wave latency decreased and the amplitude increased gradually. Regression models between visual acuity and the Pic wave latency and amplitude were also established.@*CONCLUSION@#The regression functions can be an objective and accurate method to evaluate the visual acuity based on the better simulation angles using PRVEP examination.

The progress in the study of visual field in spatial attention by event related potentials / 法医学杂志

Event-related potentials (ERP) is a good temporal resolution method to study the mechanism of visual field in brain. With the development of technique of high-density recording and brain imaging, the ERP is widely used in the location of the brain function. This article reviews the methods, results and primary conclusions in the field, and suggests several perspectives for the future research and application of ERP in the forensic science.

Effects of Jinmaitong capsule on nerve growth factor in diabetic rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effects of Jinmaitong Capsule (JMT) on the expression of NGF and NGF mRNA in STZ-induced diabetic rats.</p><p><b>METHOD</b>Fifty SZT-induced diabetic rats were randomly divided into 5 groups including model group, low-dose JMT group (treated with JMT similar to the quintupling dose of adult recommended dosage), middle-dose JMT group (treated with JMT similar to the decuple dose of adult recommended dosage), high-dose JMT group (treated with JMT similar to the twenty-fold dose of adult recommended dosage) and Neurotropin group (treated with Neurotropin similar to the decuple dose of adult recommended dosage). Ten normal rats matching with weight and age served as normal control group. All rats were given intragastric administration for 16 weeks and then killed. Body weight and blood glucose were detected before and at the 4, 8, 12, 16th week after treatment. The hydrothermal tail-flick and pain threshold to mechanical stimulation with Von Frey filament were carried out before death. The expression of NGF and NGF-mRNA in sciatic nerve were detected by SABC immunohistochemical method and real-time fluorogenetic quantitative PCR respectively.</p><p><b>RESULT</b>The blood glucose levels of STZ-DM rats were much higher than those of normal rats (P < 0.01). In all the treated groups, there were no significant differences among them compared each other or compared with model group. And it got the same result when concerning about body weight no matter how the rats were dealt with. Hydrothermal tail-flick test: The tail-flick latency of STZ-DM rats were much longer than those of normal rats (P < 0.01 or P < 0.05). Compared with model group, the time shortened significantly in low, middle-dose of JMT groups and Neutrophin group. Compared with normal group, the pain thresholds of model group decreased extremely (P < 0.01). Compared with model group, the threshold values of low-dose, middle-dose JMT group and neutrophin group raised strikingly (P < 0.05). The levels of NGF-mRNA expression in STZ-DM rats were much lower than those of the normal rats (P < 0.01). Compared with model group, NGF-mRNA expression of middle-dose JMT group and Neurotropin group upregulated noticeably (P < 0.01). The integrated option density of NGF expression in STZ-DM rats was much lower than the normal (P < 0.01 or P < 0.05). And the levels of NGF in all the treated groups increased notably compared with model group (P < 0.05 or P < 0.01). There were no significant differences among middle-dose JMT group and Neutrophin group.</p><p><b>CONCLUSION</b>Traditional Chinese medicine JMT could up-regulate the expression of NGF and NGF-mRNA in sciatic nerve.</p>

Autophagy is activated and might protect neurons from degeneration after traumatic brain injury / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To investigate changes of autophagy after traumatic brain injury (TBI) and its possible role.</p><p><b>METHODS</b>Rat TBI model was established by controlled cortical injury system. Autophagic double membrane structure was detected by transmission electronic microscope. Microtubule-associated protein 1 light chain 3 (LC3) and Beclin 1 were also used to investigate the activation of autophagy post-TBI. Double labeling with LC3 and caspase-3, or Beclin 1 and Fluoro-Jade to show the relationship between autophagy and apoptosis or neuron degeneration after TBI.</p><p><b>RESULTS</b>An increase of autophagic double membrane structure was observed in early stage (1 h), and the increase lasted for at least 32 d post-TBI. LC3 and Beclin 1 proteins also began to elevate at 1 h time point post-TBI in neurons, 3 d later in astrocytes, and peaked at about 8 d post-TBI. In both cell types, LC3 and Beclin 1 maintained at a high level until 32 d post-TBI. Most LC3 and Beclin 1 positive cells were near the side (including hippocampus), but not in the core of the injury. In addition, in the periphery of the injury site, not all caspase-3 positive (+) cells merged with LC3 (+) cells post-TBI; In hippocampal area, almost all Beclin 1 (+) neurons did not merge with Fluoro-Jade (+) neurons from 1 h to 48 h post-TBI.</p><p><b>CONCLUSION</b>Autophagy is activated and might protect neurons from degeneration at early stage post-TBI and play a continuous role afterwards in eliminating aberrant cell components.</p>

Regulation of axonal regeneration following the central nervous system injury in adult mammalian / 神经科学通报·英文版

It has been well established that the recovery ability of central nervous system (CNS) is very poor in adult mammals. As a result, CNS trauma generally leads to severe and persistent functional deficits. Thus, the investigation in this field becomes a "hot spot". Up to date, accumulating evidence supports the hypothesis that the failure of CNS neurons to regenerate is not due to their intrinsic inability to grow new axons, but due to their growth state and due to lack of a permissive growth environment. Therefore, any successful approaches to facilitate the regeneration of injured CNS axons will likely include multiple steps: keeping neurons alive in a certain growth-state, preventing the formation of a glial scar, overcoming inhibitory molecules present in the myelin debris, and giving direction to the growing axons. This brief review focused on the recent progress in the neuron regeneration of CNS in adult mammals.

Roles of NF-kappaB in central nervous system damage and repair / 神经科学通报·英文版

NF-kappaB family is a kind of nuclear factors in B lymphocyte that can bind to the immunoglobulin kappa-chain enhancer and enhance transcriptional activity. NF-kappaB/Rel proteins, as a dimeric transcription factor, control the expression of genes that regulate a broad range of biological processes through canonical and non-canonical pathways. In the central nervous system, NF-kappaB controls inflammatory reactions and the apoptotic cell death following nerve injury. It also contributes to the infarction and cell death in stroke models and patients. However, NF-kappaB is essential for neurosurvival as well. NF-kappaB activation is a part of recovery process that may protect neurons against oxidative-stresses or brain ischemia-induced apoptosis and neurodegeneration. Inhibition of NF-kappaB may reduce its neuroprotection activity. Hence the dual opposite effects of NF-kappaB on cells. The ultimate survival or death of neurons depends on which, where and when the NF-kappaB factors are activated.

Expression of cathepsin-B and -D in rat's brain after traumatic brain injury / 法医学杂志

OBJECTIVE@#To study the expression of cathepsin-B and -D in different time point after traumatic brain injury.@*METHODS@#Traumatic brain injury (TBI) model was established on rats, cathepsin-B and cathepsin-D immunofluorescence staining and confocal microscope analysis were performed. Positive cells were counted by confocal microscope and image analysis techniques were used to determine the morphological changes in each group.@*RESULTS@#Immunofluorescence staining results showed that cathepsin-B was activated 1 hour after TBI while cathepsin-D was not activated until 12hour after TBI. Both of them got to their peak during 4 to 8days, and kept a high level of activating 32days after TBI. Cathepsin-B and -D positive cells did not merge with caspase-3 positive cells until 6 h after TBI.@*CONCLUSION@#Cathepsin-B and -D could be the diagnostic markers of TBI and can estimating time course of lateral TBI. They blocked caspase-3 activation at the beginning period after TBI and started to promote cell death with caspase-3 6 h after TBI.

Electroencephalogram and evoked potential parameters examined in Chinese mild head injury patients for forensic medicine / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To evaluate the usefulness of quantitative electroencephalogram (QEEG), flash visual evoked potential (F-VEP) and auditory brainstem responses (ABR) as indicators of general neurological status.</p><p><b>METHODS</b>Comparison was conducted on healthy controls (n = 30) and patients with brain concussion (n = 60) within 24 h after traumatic brain injury. Follow-up study of patient group was completed with the same standard paradigm 3 months later. All participants were recorded in multi-modality related potential testing in both early and late concussion at the same clinical setting. Glasgow coma scale, CT scanning, and physical examinations of neuro-psychological function, optic and auditory nervous system were performed before electroencephalogram (EEG) and evoked potential (EEG-EP) testing. Any participants showed abnormal changes of clinical examinations were excluded from the study. Average power of frequency spectrum and power ratios were selected for QEEG testing, and latency and amplitude of F-VEP and ABR were recorded.</p><p><b>RESULTS</b>Between patients and normal controls, the results indicated: (1) Highly significance (P < 0.01) in average power of α1 and power ratios of θ/α1, θ/α2, α1/α2 of EEG recording; (2) N70-P100 amplitude of F-VEP in significant difference at early brain concussion; and (3) apparent prolongation of I-III inter-peak latency of ABR appeared in some individuals at early stage after concussion. The follow-up study showed that some patients with concussion were also afflicted with characteristic changes of EEG components for both increments of α1 average power and θ/α2 power ratio after 3 months recording.</p><p><b>CONCLUSION</b>EEG testing has been shown to be more effective and sensitive than evoked potential tests alone on detecting functional state of patients with mild traumatic brain injury (MTBI). Increments of α1 average power and θ/α2 power ratio are the sensitive EEG parameters to determining early concussion and evaluating outcome of post-concussion symptoms (PCS). Follow-up study associated with persistent PCS may be consistent with the postulate of substantial biological, rather than psychological origin. The study suggests that combination of EEG and EP parameters can contribute to the evaluation of brain function as a whole for clinical and forensic applications.</p>

The study on expression of NF-kappaB in experimental brain contusion in rats / 法医学杂志

OBJECTIVE@#To investigate the expression of NF-kappaB in different post-traumatic intervals and severity of brain injury.@*METHODS@#Fifty-four brain tissue samples of slight (n=24), moderate (n=24) brain injury, sham (n=3) and control (n=3) of rat were examined by immunohistochemical staining, westernblot and RT-PCR.@*RESULTS@#Up-regulating of NF-kappaB expression was found in tissues from traumatic brain injury compared with controls in early 1 hour after TBI, and reached peak at 24h and 48h and disappeared after 7 days. The expression of NF-kappaB mRNA has association with contusion severity.@*CONCLUSION@#NF-kappaB may benefit to the estimation of posttraumatic intervals of brain injury.

The study on the expression of caspase-3 in experimental brain contusion in rats / 法医学杂志

OBJECTIVE@#To investigate the expression of caspase-3 in different posttraumatic intervals and severity of brain injury.@*METHODS@#The study examined brain tissue samples of slight (n = 24), severe (n = 24) brain injury and control (n = 6) of rat, using immunohistochemical staining, western-blot and RT-PCR method.@*RESULTS@#Up-regulating of caspase-3 expression was found in tissue from traumatic brain injury compared with controls in early 1 hour after TBI, and lasted for 14 days. The gray degree and threshold area of caspase-3 positive cells is different in different severity of brain injury.@*CONCLUSION@#The increasing of caspase-3 expression indicates that TBI exists. The gray degree, threshold area of caspase-3 positive cells and the cleavage degree of pro-caspase-3 have association with the severity of brain injury.

A study on myogenic differentiation of human adipose tissue-derived stromal cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To isolate human adipose tissue-derived stromal cells and study the potential of osteogenic differentiation after inductive culture.</p><p><b>METHODS</b>Liposuction human adipose tissues were minced and digested with collagenase type I. The obtained stromal cells were plated in BGJb medium as primary culture for ten days. The second passage cells were harvested and plated in DMEM/F12 medium supplemented with 10% FBS, 5% horse serum and 50 micromol/L hydrocortisone for myogenic induction culture. The cell-anchored slips were removed and fixed in 4% formaldehydam polymerisatum. Toluidine blue, Mallory's phosphotungstic hematoxylin staining and monoclonal antibody to human skeletal muscle myosin heavy chain immunocytochemical methods were used to assay the differentiation of cells.</p><p><b>RESULTS</b>It was observed that the size and shape of induced cells were much different from those of non-induced cells. Toluidine blue, Mallory's phosphotungstic hematoxylin staining demonstrated there were many basophilic striations within cytoplasm and multinucleated myotubes were formed. Immunocytochemical stain indicated that characterastic skeletal myosin heavy chain was positive in myogenic induced cells.</p><p><b>CONCLUSION</b>It seems that human adipose tissue represents an abundant reservoir of adult stem cells that have multi-germline potential to differentiate into myoblasts. Adipose tissue derived stromal cells will be another alternative source for cell-based tissue engineering in skeletal muscle reconstruction.</p>

Traumatic brain injury and caspase / 法医学杂志

Many pathologic and physiologic changes occur after brain injury. Many genes control these changes. Caspase plays an important role in neuron cell apoptosis and has concern with secondary brain injury. It is of great significance in the forensic science.

The study on expression of caspase-1 in experimental brain contusion of different severity in rats / 法医学杂志

OBJECTIVE@#To investigate the expression of caspase-1 in different posttraumatic intervals and severity of brain injury.@*METHODS@#The study examined brain tissue samples of slight (n = 24), severe (n = 24) brain injury and control (n = 6) of rat, using immunohistochemical staining, western-blot and RT-PCR method.@*RESULTS@#Up-regulating of caspase-1 expression was found in tissue from traumatic brain injury compared with controls in early 1 hour after TBI, and lasted for 2 weeks. Caspase-1 cleaved after brain injury.@*CONCLUSION@#These findings are the first time to demonstrate the study of different intense brain injury. The increasing of caspase-1 expression indicates that the TBI exists. The threshold area of caspase-1 positive cells is different in different severity of brain injury.