OBJECTIVE: To study the expression of nerve growth factor (NGF) in diffuse axonal injury (DAI) in rat. METHODS: Eighty SD rats were used and samples were taken at 1 h, 3 h, 6 h, 12 h, 24 h, 48 h, 3 d, and 7 d after brain injury. The expressions of NGF in cerebral cortex, thalamus, cerebellum, and hippocampus were studied with immunohistochemistry and compared with normal group and sham operation group. RESULTS: Low expression of NGF was observed in normal group and sham operation group. The expression of NGF increased 1 h after injury, peaked at 12 h, and returned to basal level at day 7. CONCLUSION NGF is involved in repair of DAI. The changes of NGF expression following DAI may be applied to estimate the post-injury time interval of the brain in forensic medicine.
Animals ; Brain Injuries/metabolism* ; Diffuse Axonal Injury/metabolism* ; Forensic Pathology ; Male ; Nerve Growth Factors/metabolism* ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To examine the differential expression of protein of thalamus in rats with diffuse axonal injury. METHODS: Twenty-five rats were randomly divided into a normal group (n=10) and a trauma group (n=15). Total proteins of brain trauma tissue and normal brain tissue were extracted separately, and then proteins were separated by two dimensional gel electrophoresis and stained with Coomassie brilliant blue. The differentially expressed protein spots were identified with biospectrometry. Images were analyzed by PDQuest 7.0. RESULTS: The distribution of protein spots in the trauma group was similar to that of the normal group, the matching rate was 95%, and the repeatability was good. Proteins were mainly displayed at pI 3-8, with relative molecular mass 14.4-75.0 kD. Compared with the normal group, 16 spots of proteins increased and 18 spots of proteins decreased in the trauma group. CONCLUSION There is some difference in protein expression between the normal group and the trauma group. Brain trauma may lead to changes of proteins in the thalamus.
Animals ; Diffuse Axonal Injury ; metabolism ; Electrophoresis, Gel, Two-Dimensional ; Male ; Proteome ; analysis ; Proteomics ; methods ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Thalamus ; metabolism

OBJECTIVES: To establish the imaging mass spectrometry for analysis of differentially expressed proteins distribution in the rat brains with diffuse axonal injury （DAI） based on matrix assisted laser desorption/ionization-time of flight imaging mass spectrometry （MALDI-TOF-IMS）. METHODS: MALDI-TOF-IMS scanning were conducted on the brains of DAI group and control group in the m/z range of 1 000 to 20 000 using AutoflexⅢ MALDI-TOF spectrometer. ClinProTool 2.2 software was used for statistical analysis on the data of two groups, and then the differentially expressed proteins were picked out to conduct imaging. The distribution of the proteins with different m/z in the rat brains was observed. RESULTS: Five proteins with different m/z, including 4 963, 5 634, 6 253, 6 714 and 7 532, differentially expressed in the rat brains with DAI. CONCLUSIONS MALDI-TOF-IMS can be used for studying the differentially expressed proteins in rat brains with DAI and the analysis method is established for exploring the distribution of differentially expressed proteins in the rat brains with DAI using imaging mass spectrometry.
Animals ; Brain/pathology* ; Diffuse Axonal Injury/pathology* ; Proteins/metabolism* ; Proteome/metabolism* ; Proteomics ; Rats ; Software ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Although nitric oxide (NO) plays an important role in the pathophysiological process of cerebral ischemia or severe traumatic brain injury, its contribution to the pathogenesis of moderate diffuse axonal injury (mDAI) remains to be clarified. The alterations in nitric oxide synthase (NOS) activity and the histopathological response after mDAI was investigated. Forty anesthetized Sprague-Dawley adult rats were injured with a Marmarou's weight-drop device through a Plexiglas guide tube. These rats were divided into 8 groups (control, 1 hr, 2 hr, 3 hr, 6 hr, 12 hr, 24 hr, 48 hr after trauma). The temporal pattern of apoptosis in the adult rat brain after mDAI was characterized using TUNEL histochemistry. In addition, the cDNA for NOS activity was amplified using RT-PCR. The PCR products were electrophoresed on a 2% agarose gel. eNOS activity was not detected, but nNOS activity was expressed after 3 hr and continuously 48 hr after impact, which was approximately double that of the control group at 12 and 24 hr. Subsequently, there was a decrease in activity after 48 hr. The iNOS activity increased dramatically after 12 hr and was constant for a further 12 hr followed by a dramatic decrease below the level of the control group. Significant apoptotic changes occurred 12 and 24 hr. after insult. nNOS and iNOS activity were affected after moderate diffuse axonal injury in a time-dependent manner and there was a close relation between the apoptotic changes and NOS activity. Although the nNOS activity was expressed early, its activity was not stronger th an iNOS, which was expressed later.
Animal ; *Apoptosis ; Craniocerebral Trauma/enzymology/*physiopathology ; Diffuse Axonal Injury/enzymology/*physiopathology ; Nitric-Oxide Synthase/*metabolism ; Rats ; Rats, Sprague-Dawley ; Wounds, Nonpenetrating/enzymology/*physiopathology

OBJECTIVE: To explore the changes of expression of heat-shock proteins (HSP) 70 mRNA in hippocampus of rats after diffuse axonal injury (DAI). METHODS: RT-PCR products of HSP70 mRNA were tested by agarose gel electrophoresis after RT-PCR amplification. The changes of HSP70 mRNA expression were observed in rat hippocampus after DAI. RESULTS: The expression of HSP70 mRNA in the hippocampus could be detected 4 h after DAI. It reached maximum at 24 h and declined after 48 h. CONCLUSION HSP70 mRNA in hippocampus of rats could be useful for diagnosis of DAI.
Animals ; Axons/pathology* ; Diffuse Axonal Injury/pathology* ; Disease Models, Animal ; Forensic Pathology ; HSP70 Heat-Shock Proteins/metabolism* ; Hippocampus/metabolism* ; Male ; RNA, Messenger/metabolism* ; Random Allocation ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Time Factors

OBJECTIVE: To explore an method for diffuse axonal injury (DAI) diagnosis and injury time estimation, the changes of beta-APP immunoreactivity and to observe the morphology of axonal in different parts of brain after experimental DAI injury. METHODS: The animal models of DAI was established according to the Marmarou's method. Immunohistochemistry and Gless staining were performed to observe the changes of beta-APP expression and the morphology of axon with the time elapsed after the DAI injury. RESULTS: In the brain injury group, the morphologic changes of axon in brain stem were showed as twisted, broken and swellen at 0.5 h, and the myelin sheaths broken could be observed, the retraction ball was found at 12 h. Those morphology changes further progressed at 12h, reached to peack up to 1 d, then repaired at 3 d, and recovered at 10 d; Meanwhile the analysis of beta-APP immunoreactivity was also showed a time-dependent difference as fellows: beta-APP expression begin at 3h, increased its immunoreactivity at 12h, reached to maximize at 1 d, decreased after 3 d, returned to basal level at 10 d. CONCLUSIONS The results suggest that beta-APP immunohistochemistry combine with Gless staining be sensitive methods for DAI diagnosis, they could discover the time-dependent changes of the axonal morphology.The changes beta-APP are quite regular and could be used for timing DAI injury.
Amyloid beta-Protein Precursor/metabolism* ; Animals ; Axons/pathology* ; Brain Stem/pathology* ; Diffuse Axonal Injury/pathology* ; Disease Models, Animal ; Female ; Immunohistochemistry/methods* ; Male ; Rats ; Rats, Sprague-Dawley ; Staining and Labeling ; Time Factors

OBJECT: To investigate the changes in the expression_level of synaptophysin following diffuse brain injury (DBI) in rats and to correlate the changes of the synaptophysin expression_level with the post injury time interval. METHODS: Wister rats were used as a DBI model induced by Marmarou method. The changes of synaptophysin immunoreactivity on coronal sections of the rats sampled at different post-injury time intervals were used as a marker. The densitometry of the synaptophysin immunoreactivity was documented by imaging technique and analyzed by SPSS software. RESULTS: The expression level of synaptophysin in DBI rats showed dynamic changes following DBI as well as during the repairing period. CONCLUSION The changes of synaptophysin level may be used as a marker for estimation of the post injury time interval in DBI.
Animals ; Brain/pathology* ; Brain Injuries/pathology* ; Cerebral Cortex/pathology* ; Diffuse Axonal Injury/pathology* ; Disease Models, Animal ; Immunohistochemistry ; Intracranial Hemorrhage, Traumatic/pathology* ; Neurons/pathology* ; Rats ; Rats, Sprague-Dawley ; Staining and Labeling ; Synapses/pathology* ; Synaptophysin/metabolism* ; Time Factors

OBJECTIVE: To establish a diagnostic model for diffuse axonal injury (DAI) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). To screen the proteins or peptides associated with DAI for providing the biomarkers with theoretic foundation. METHODS: Fifteen male Sprague-Dawley rats were randomly divided into DAI group (n = 10) and control group (n = 5). The protein or peptide expression profiles of rat brain stem were detected by MALDI-TOF-MS. ClinProTools 2.2 software was used to find specific peaks, and a diagnostic model was established by the genetic algorithm. RESULTS: There were significant differences in 61 peaks of DAI group (P < 0.05), 9 peaks were down-regulated and 52 up-regulated. The diagnostic model was established based on 5 different peaks. The specificity and sensitivity of cross validation was 96.14% and 95.98%; while the specificity and sensitivity of blind validation showed was 73.33% and 70.00%, respectively. CONCLUSION A specific and sensitive diagnostic model of DAI can be established by MALDI-TOF-MS to provide a potential value for determining DAI in forensic practice.
Animals ; Biomarkers ; Brain Stem/metabolism* ; Diffuse Axonal Injury/diagnosis* ; Down-Regulation ; Male ; Peptides/blood* ; Proteomics ; Rats ; Rats, Sprague-Dawley ; Sensitivity and Specificity ; Software ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods* ; Up-Regulation