ABSTRACT
Objective:To investigate the early changes of serum biomarkers in rats with mild blast-induced traumatic brain injury (bTBI) in cabin.Methods:Explosion source in the simulated cabin was detonated by initiator. The bTBI rat models caused by explosion shock wave in cabin were established. A total of 24 adult male Sprague-Dawley rats were divided into normal control group ( n=6) and bTBI group ( n=18), according to the random number table. Rats in bTBI group were subdivided at 3, 24, and 72 h post-blast, with 6 rats at each time point. Shock wave pressure at the rat head was measured during the explosion. At 3, 24, and 72 h post-blast, the general condition of rats was observed. Rat blood was collected by cardiac puncture. Then brains were taken completely and quickly for pathological observation. HE staining was used to observe the changes of neurons in hippocampal CA1 area. The collected serum was tested for levels of biomarkers, including interleukin- 6 (IL-6), neuron specific enolase(NSE), S100-β, alpha Ⅱ-spectrin breakdown product-145 (SBDP-145) and Tau. Results:The maximum peak value of the shock wave pressure curve at the rat head was (818.2±33.3)kPa, and the duration was about 1 000 μs. After the explosion, the activity of the rats decreased significantly, the hair was dull, and the appetite decreased. General observation showed that the brain tissue was obviously swollen, the blood vessels on the brain surface were thickened, and there was a little patchy bleeding, but no obvious brain contusion was seen. HE staining showed that some neurons in the hippocampus CA1 area had apoptosis or necrosis. At 3, 24, and 72 hours post-blast, the levels of IL-6 were (155.3±10.7)pg/ml, (171.3±25.3)pg/ml and (155.6±18.2)pg/ml, all of which were significantly higher than that in normal control group [(116.3±7.3)pg/ml]( P<0.05); the levels of NSE were (12.0±1.0)ng/ml, (11.0±1.0)ng/ml and (11.0±1.2)ng/ml, all of which were significantly higher than that in normal control group [(8.1±0.5)ng/ml]( P<0.05); the levels of S100-β were (71.9±10.7)pg/ml, (58.0±11.5)pg/ml and (56.5±12.2)pg/ml, all of which were significantly higher than that in normal control group [(35.2±2.5)pg/ml] ( P<0.05); the levels of SBDP-145 were (29.4±2.8)ng/ml, (24.5±4.8)ng/ml and (20.7±2.1)ng/ml, and only the level at 3 h post-blast was significantly higher than that in normal control group [(20.9±1.2)ng/ml]( P<0.05); the levels of Tau were (141.4±11.7)pg/ml, (189.5±28.2)pg/ml and (179.1±32.5)pg/ml, all of which were significantly higher than that in normal control group [(97.8±5.9)pg/ml]( P<0.05). Conclusion:The serum levels of IL-6, NSE, S100-β, SBDP-145 and Tau in mild bTBI rats increase in various degrees at early time, which provides a theoretical basis for use of serum markers in the early diagnosis of mild bTBI.
ABSTRACT
Objective Through the establishment of adjacent cabin blast injury model of Beagle dog,to investigate the pathophysiological changes in the experimental animals in this scenario,then speculate on the mechanisms of injury.Methods Several adjacent cabins were built in the same size with the real warship.Seven Beagle dogs were subjected to injuries from the explosion,from whom one was selected randomly to implant intracranial pressure transducers before blast,the others were tested on the pathophysiological changes after blast.The dogs were mounted on the platform of a cabinet in the adjacent cabin,subjected to injury from 650g bare TNT explosive blast.The transducers recorded the value of space and intracranial shock wave pressure.Following blast treatment,the serum levels of IL-6,IL-8,neuron specific enolase (NSE),brain and chest CT and pathological changes of the brain tissue were observed.Results Serum levels of IL-6,IL-8 and NSE were elevated to varying degrees after blast.All of them increased significantly at different time points after blast (P＜0.05).Brain and chest CT examinations did not show any significant positive results.Pathological results showed that there was a little necrosis in the brain,some neurons had karyopycnosis,karyolysis or disappearance of the nucleoli,and the cell boundaries were blurred.The blast wave was blocked greatly by the scalp and skull (about 90％),but could still penetrate them and cause brain injuries.Conclusions Explosion in the adjacent cabin causes mainly mild traumatic brain injuries.Blast wave can be blocked by the scalp and skull greatly.
ABSTRACT
An investigation of the eruption of the mandibular third molar and an analysis of the causes of their impaction and absence were made. On macroscopic and X-ray examination, the rate of the impaction and absence was 19.74％ and 28.95％. respectively.In the analysis of the causes of the impaction and the absence of mandibular third molars we found that besides the length of the region posterior to the second molar already reported, the frequency of crowded teeth in the normal and in the impacted group is higher than that in the absent group. The mediodistal diameters of the mandibular second molar and first molar, which in the normal group are bigger than those in the other groups, also influence the eruption of the mandibular molars.