OBJECTIVETo establish a simple, reproducible, and practical mechanical injury model of hippocampal neurons of Sprague-Dawley rats in vitro.

METHODSHippocampal neurons isolated from 1-2-day old rats were cultured in vitro. Mild, moderate and severe mechanical injuries were delivered to the neurons by syringe needle tearing, respectively. The control neurons were treated identically with the exception of trauma. Cell damage was assessed by measuring the Propidium Iodide (PI) uptaking at different time points (0.5, 1, 6, 12 and 24 hours) after injury. The concentration of neuron specific enolase was also measured at some time points.

RESULTSPathological examination showed that degeneration, degradation and necrosis occurred in the injured cultured neurons. Compared with the control group, the ratio of PI-positive cells in the injured groups increased significantly after 30 minutes of injury (P<0.05). More severe the damage was, more PI-positive neurons were detected. Compared with the control group, the concentration of neuron specific enolase in the injured culture increased significantly after 1 hour of injury (P<0.05).

CONCLUSIONSThe established model of hippocampal neuron injury in vitro can be repeated easily and can simulate the damage mechanism of traumatic brain injury, which can be used in the future research of traumatic brain injury.

Analysis of Variance ; Animals ; Brain Injuries ; enzymology ; pathology ; Equipment Design ; Hippocampus ; enzymology ; injuries ; In Vitro Techniques ; Neurons ; enzymology ; pathology ; Phosphopyruvate Hydratase ; biosynthesis ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reproducibility of Results

OBJECTIVETo investigate the protective effect of mild hypothermia on rat astrocytes with traumatic or ischemic injury.

METHODSRat astrocytes in primary culture were subjected to scratching or hypoxic injury and exposed to normothermia (37 degrees celsius;) or hypothermia (34 or 32 degrees celsius;) for 24 h. The morphology of the astrocytes was evaluated by live/dead staining, and the cell injury was measured by lactate dehydrogenase (LDH) release assay.

RESULTSAs the temperature reduced the LDH release rate from the cells in hypoxic group decreased significantly, to (11.48 - or + 1.53)% at 34 degrees celsius; and (3.79 - or + 0.45)% at 32 degrees celsius; as compared to that in normothermia [(33.02 - or + 3.58)%] in the absence of rat white blood cells (WBC) (P<0.001). LDH release rate of the hypoxic cells further decreased in the presence of rat WBC to (51.14 - or + 2.17 )% at 37 degrees celsius;, (19.53 - or + 4.37)% at 34 degrees celsius; and (16.68 - or + 1.47)% at 32 degrees celsius; (P<0.001). In the scratched cells, with or without WBC, LDH release rate showed no significant variation between the 3 temperatures (P>0.05).

CONCLUSIONMild hypothermia offers obvious protective effects on rat astrocytes against ischemic damage but not against mechanical injury.

Animals ; Animals, Newborn ; Astrocytes ; enzymology ; pathology ; Brain Injuries ; therapy ; Brain Ischemia ; therapy ; Cell Hypoxia ; Cells, Cultured ; Cold Temperature ; L-Lactate Dehydrogenase ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the association between serum neuron-specific enolase (NSE) and the extent of brain damage and the outcome after acute traumatic brain injury (TBI).

METHODSThe release patterns of serum NSE in 78 patients after acute TBI were analyzed by using the enzyme linked immunosorbent assay. The levels of NSE were compared with Glasgow coma scale, the category of brain injury and the outcome after 6 months of injury.

RESULTSThere were different NSE values in patients with minor (12.96 microg/L+/-2.39 microg/L), moderate (23.44 microg/L+/-5.33 microg/L) and severe brain injury (42.68 microg/L+/-4.57 microg/L). After severe TBI, the concentration of NSE in patients with epidural hematomas was 13.38 microg/L+/-4.01 microg/L, 24.03 microg/L+/-2.85 microg/L in brain contusion without surgical intervention group, 55.20 microg/L+/-6.35 microg/L in brain contusion with surgical intervention group, and 83.85 microg/L+/-15.82 microg/L in diffuse brain swelling group. There were close correlations between NSE values and Glasgow coma scale (r=-0.608, P<0.01) and the extent of brain injury (r=0.75, P<0.01). Patients with poor outcome had significantly higher initial and peak NSE values than those with good outcome (66.40 microg/L+/-9.46 microg/L, 94.24 microg/L+/-13.75 microg/L vs 32.16 microg/L+/-4.21 microg/L, 34.08 microg/L+/-4.40 microg/L, P<0.01, respectively). Initial NSE values were negatively related to the outcome (r=-0.501, P<0.01). Most patients with poor outcomes had persisting or secondary elevated NSE values.

CONCLUSIONSSerum NSE is one of the valuable neurobiochemical markers for assessment of the severity of brain injury and outcome prediction.

Acute Disease ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Brain Injuries ; enzymology ; Child ; Humans ; Middle Aged ; Phosphopyruvate Hydratase ; blood ; Whole-Body Irradiation

OBJECTIVE: To investigate the expression of matrix metalloproteinase-3 after brain contusion and its applicability for estimating the age of brain contusion. METHODS: Rats had been divided into three groups: control group, sham operation group and brain contusion group. The expression of matrix metalloproteinase-3 at different time was detected by immunohistochemistry and Western blot. RESULTS: By the immunohistochemistry, no staining was observed in control and sham operation groups. The positive staining of MMP-3 appeared 6 hours after contusion, increased gradually in 24 hours and peaked 5 days after contusion, then started to decrease, 14 days after contusion still could be observed. By the Western blot analysis, no expression of MMP-3 was detected in control and sham groups. The positive staining of MMP-3 appeared 6 hours after contusion, increased gradually and maximized 5 days after contusion, then started to decrease, 14 days after contusion still could be found. CONCLUSION Time-order expression of MMP-3 could be used for estimating the age of brain contusion in forensic pathology.
Animals ; Blotting, Western ; Brain Injuries/enzymology* ; Forensic Pathology ; Immunohistochemistry ; Male ; Matrix Metalloproteinase 3/genetics* ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Time Factors

OBJECTIVETo analyze the role of Caspase 3 in neuronal apoptosis after acute brain injury.

METHODSExperiments were carried out with rat diffuse brain trauma model. The neuronal DNA injury in cortex and hippocampus was observed by TUNEL stain. The mRNA and protein expressions and enzyme activation of Caspase 3 were observed by Northern blot, in situ hybridization, immunohistochemistry stain and Western blot, respectively. Special Caspase 3 enzyme inhibitor was used to observe the therapeutic effect.

RESULTSTUNEL positive neurons appeared 2 hours after severe trauma, peaked at 1 day and lasted for 7 days. Northern blot showed that the Caspase 3 mRNA expression was increased and peaked at 1 day, about twice higher than the control. In the area of cortex and hippocampus, positive mRNA staining neurons appeared most distinct on one day. With the antibody for Caspase 3 P20 subunit, the active Caspase 3 expression peaked at 1-3 days. The electrophoresis band of PARP degradation would be seen by Western blot. Caspase 3 enzyme inhibitor could reduce apoptotic neuronal death without any effect on Caspase 3 P20 subunit expression.

CONCLUSIONSAfter brain trauma, Caspase 3 mRNA and protein expressions and enzyme activation are enhanced in combination with neuronal apoptosis. Special Caspase 3 enzyme inhibitor can apparently decrease the neuronal apoptosis.

Acute Disease ; Animals ; Apoptosis ; physiology ; Brain Injuries ; enzymology ; physiopathology ; Caspase 3 ; Caspases ; metabolism ; Enzyme Activation ; Enzyme Inhibitors ; pharmacology ; Nervous System ; physiopathology ; Neurons ; enzymology ; physiology ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo evaluate protective effects of Rheum tanguticum polysaccharides (RTP) on traumatic brain injury (TBI) in rats.

METHODThe polysaccharides (RTP) were extracted from Tanguficum Maxim. 120 rats were divided into 15 groups, with 8 rats in each group. RTP at 100, 200 and 400 mg x kg(-1) were administrated orally once a day for five days, and model of brain injury was made by dropping weight method.

RESULTRTP reduced water content and malondialdehyde (MDA) levels, and increased total SOD activity and Na+-K+ ATPase activity after injuried.

CONCLUSIONThe polysaccharides may be one of the effective comptents in Rheum tanguticum, showing significant neuroprotective effects.

Animals ; Brain Injuries ; enzymology ; metabolism ; pathology ; Cerebral Cortex ; enzymology ; ultrastructure ; Male ; Malondialdehyde ; metabolism ; Neuroprotective Agents ; pharmacology ; Plants, Medicinal ; chemistry ; Polysaccharides ; isolation & purification ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Rheum ; chemistry ; Sodium-Potassium-Exchanging ATPase ; metabolism ; Superoxide Dismutase ; metabolism

OBJECTIVE: To illuminate the pathology of traumatic brain injury(TBI) and to better understand the relationship between the expression of COX-2 and the time course of TBI. METHODS: Immunocytochemical staining, double-labeled with the anti-COX-2 antibody and either the neuron-specific antibody NeuN or the astroglial-specific marker GFAP, in situ hybridization and computer image analysis were used. RESULTS: Results from immunohistochemistry indicated time-dependent staining changes of neuronal plasma. The immunostained cells were faint at control cortex, mostly were neurons. The immunostained cells appeared to be darkly stained 30 min after TBI for extended periods of time and reached the maximum at 2 d after injury, reached another peak (P < 0.05) at 4 d post-injury. The darker cells persisted in a high level, significant differences (P < 0.05) even presented between control and 15 d post-injury. The COX-2 mRNA expression was faint at control cortex. The expressions of COX-2 mRNA appeared to be darkly stained 15 min after TBI for extended periods of time and reached the maximum (P < 0.05) at 1 d post-injury, reached another peak (P < 0.05) at 3 d post-injury, and significant differences (P < 0.05) even presented between control and 7 d post-injury, but not 15 d post-injury. CONCLUSION The results of this study indicated that the expression of COX-2 mRNA and protein had a possible relationship with the extended periods of time after TBI. It might have some relationship between the expression of COX-2 and secondary brain injury after TBI.
Animals ; Apoptosis ; Brain Injuries/enzymology* ; Cyclooxygenase 2 ; Gene Expression ; Immunohistochemistry ; In Situ Hybridization ; Isoenzymes/genetics* ; Male ; Neurons/enzymology* ; Prostaglandin-Endoperoxide Synthases/genetics* ; RNA, Messenger/biosynthesis* ; Rats ; Rats, Sprague-Dawley ; Staining and Labeling ; Time Factors

OBJECTIVETo explore changes of neuronal calcium channel following brain damage induced by injection of pertussis bacilli in rats, and to investigate the relationship between cytosolic free calcium concentration ([Ca(2+)](i)) in the synaptosome and Ca(2+)-ATPase activities of mitochondria.

METHODSThe level of [Ca(2+)](i) in the synaptosome and Ca(2+)-ATPase activities of mitochondria in the acute brain damage induced by injection of pertussis bacilli (PB) in rat was determined and nimodipine was administrated to show its effects on [Ca(2+)](i) in the synaptosome and on alteration of Ca(2+)-ATPase activity in the mitochondria. Seventy-three rats were randomly divided into four groups, ie, normal control group (Group A), sham-operation control group (Group B), PB group (Group C) and nimodipine treatment group (Group D).

RESULTSThe level of [Ca(2+)](i) was significantly increased in the PB-injected cerebral hemisphere in the Group C as compared with that in the Group A and the Group B at 30 minutes after injection of PB. The level of [Ca(2+)](i) was kept higher in the 4 hours and 24 hours subgroups after the injection in the Group C (P<0.05). In contrast, the Ca(2+)-ATPase activities were decreased remarkably among all of the subgroups in the Group C. Nimodipine, which was administered after injection of PB, could significantly decrease the [Ca(2+)](i) and increase the activity of Ca(2+)-ATPase (P<0.05).

CONCLUSIONSThe neuronal calcium channel is opened after injection of PB. There is a negative correlation between activities of Ca(2+)-ATPase and [Ca(2+)](i). Nimodipine can reduce brain damage through stimulating the activities of Ca(2+)-ATPase in the mitochondria, and decrease the level of [Ca(2+)](i) in the synaptosome. Treatment with nimodipine dramatically reduces the effects of brain damage induced by injection of PB.

Analysis of Variance ; Animals ; Bordetella pertussis ; Brain Injuries ; metabolism ; Calcium ; metabolism ; Calcium Channel Blockers ; pharmacology ; Calcium-Transporting ATPases ; metabolism ; Cytosol ; metabolism ; Mitochondria ; enzymology ; Nimodipine ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Synaptosomes ; metabolism

It has been suggested that propofol has the protective effect on cerebral ischemia-reperfusion injury. The aim of this study is to evaluate the effect of propofol pretreatment on incomplete forebrain ischemia-reperfusion injury in rats. Thirty Sprague-Dawley rats were anesthetized with isoflurane in oxygen and randomly allocated into propofol group (n=13) and saline group (n=17). In propofol group, propofol was pretreated in a step-down scheme before inducing forebrain ischemia by occlusion of both common carotid arteries and arterial hypotension. After ischemia (20 min) and reperfusion (30 min), rats were decapitated. Brain was sliced to obtain coronal slices of 4-12 mm from frontal pole, which were reacted with 2% 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) for 10 min to differentiate the damaged tissues from normal tissues. Median (interquartile range) values of the average percent infarct area were 0.0 (8.6)% and 20.1 (41.2)% in propofol and saline groups, respectively. There was significant difference between the groups. In conclusion, propofol may have a protective effect on incomplete forebrain ischemia-reperfusion injury.
Animal ; Brain Ischemia/prevention & control* ; Brain Ischemia/pathology ; Cerebral Infarction/prevention & control ; Cerebral Infarction/pathology ; Disease Models, Animal ; Free Radical Scavengers/pharmacology* ; Mitochondria/enzymology* ; Neuroprotective Agents/pharmacology* ; Oxidative Phosphorylation ; Propofol/pharmacology* ; Prosencephalon/metabolism ; Prosencephalon/injuries ; Prosencephalon/drug effects* ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury/prevention & control* ; Reperfusion Injury/pathology ; Tetrazolium Salts