ABSTRACT
Objective To investigate the effect of adenosine A2A receptor on pituitary-adrenal axis response in acute phase of moderate craniocerebral trauma.Methods Eighteen adenosine A2A receptor knock-out mice in a C57BL/6 background and another eighteen their wild-type littermates were divided into normal control group and craniocerebral trauma for 4 hours group,and craniocerebral trauma for 24 hours group according to random number table,with siμ mice per group.Plasma levels of adrenocorticotropic-hormone (ACTH) and corticosterone at hours 4 and 24 postinjury were determined using ELISA method.Results At 4 and 24 hours,brain water content in wild-type mice [(80.950 ± 0.184) ％,(82.178 ± 0.255)％ respectively] was higher than that in gene knock-out mice [(80.006 ± 0.199)％,(81.091 ± 0.295)％ respectively,P ＜ 0.01].Besides,brain water content in both wild-type and gene knock-out mice increased after injury (P ＜ 0.01).Plasma levels of ACTH and corticosterone were higher in geneknock-out sham mice than in wild-type sham mice [(120.214 ± 2.472) ng/L vs (91.767 ±7.395) ng/L,(27.814 ±0.888) μg/L vs (11.430 ±0.644) μg/L respectively,P ＜0.0l].At 4 and 24 hours,plasma levels of ACTH [(174.776-± 5.040) ng/L,(189.613 ± 4.802) ng/L respectively] in geneknock-out mice showed a higher increase than those in wild-type mice [(119.594 ± 6.945) ng/L,(124.93-± 11.001 7) ng/L respectively,P ＜ 0.05].Moreover,plasma levels of corticosterone [(40.138 ±-0.805) μg/L] at 4 hours and [(37.440-0.485)μg/L] at 24 hours in gene knock-out mice showed a same result as compared with that in wild-type mice [(19.702 ± 0.804) μg/L,(17.602 ± 0.743) μg/L respectively,P ＜ 0.05].Conclusions Knock-out of adenosine A2A receptor increases the release of ACTH and corticosterone in acute stage of moderate craniocerebral trauma and promotes pituitary-adrenal stress response.This may provide a novel explanation for the neuroprotective effect of A2A receptor deficiency.
ABSTRACT
Objective To find out the accurate resonance frequencies and vibration characteristics of intestine,lung,kidney,stomach,heart and liver of rat and rabbit in low frequency and to provide basic data for the study of organs' resonance injury and reaction.Methods Eight rats and eight rabbits were anaesthetized with 1.5％ sodium pentobarbital and acceleration sensor was fixed to the surface of their bowels.The rats were fastened on their back on the veneer hung horizontally by rubber band.The veneer was hammered upward from the down side,and the biggest value of frequency spectrum was considered the resonance frequency.Rabbits were fastened on their back on vibration platform and 2 mm amplitude vibration was given with the sweeping-frequency from 2 Hz to 50 Hz.The bowels amplitudes on each frequency point were measured.The frequency corresponding to the biggest amplitude was considered the resonance frequency.Results The resonance frequencies of rat intestine,lung,kidney,stomach,heart and liver were respectively 3.8,3.2,6.6,7.0,4,6 and 3.0 Hz within frequency interval of 0 Hz to 20 Hz.The resonance frequencies of rabbit intestine,lung,kidney,stomach,heart and liver were respectively 6.0,5.0,7.0,8.0,6.0 and 7.0 Hz within frequency interval of 2 Hz to 50 Hz.The vibration amplitude of lung was the biggest at the resonance frequency.The resonance frequencies of both rat and rabbit bowels showed no statistical correlations to body weights,bowel mass and bowel volumes.Conclusion Bowel resonance frequencies of rat and that of rabbit are evidently statistical different except for that of kidney.The resonance frequency values of rabbit bowels are closer to that of dog and monkey than to that of rat.Thus the resonance injury characteristic of rabbit bowels can be the research basis for dog,monkey,and even human bowels resonance injury.
ABSTRACT
Objective To study the characteristics of the sciatic nerve injuries inflicted by highvelocity triangle fragments in swine.Methods According to the injury position,14 swines weighing (34.29±5.2)kg were divided into two groups.All swines were shot by 0.37 g triangle fragments at (773.1±12.4)m/s aimed at the midpoint of the lateral body surface projection of the right sciatic nerve in Group A(n=7)and at 2 cm aside from sciatic nerve in Group B(n=7).The entrance,exit and length of wound tract,distance between nerve and wound tract were detected,and the pathology of sciatic nerve and wound tract at 48 hours after injury were observed under light microscope and electron microscope.Results The course of the fragments was deviated to different extent.Six sciatic nerves were in primary wound tract,four of which were lacerated and ruptured at different degrees.The light microscope showed pathological changes including severe hemorrhage and edema,leukocytic infiltration,neurotmesis,axonotmesis and light myelin coloration;while electron microscope showed severe degeneration of myelin sheath and neuraxon distortion.Six nerves(one in Group A and five in Group B)were in the concussion zone,with the distance between sciatic nerve and primary wound tract for(2.07±0.45)cm.Hyporrhea and hyperemia under perilemma and perineurium,partial nerve fiber disrupt and axonotmesis were observed by light microscope and partly myelin sheath delamination by electron microscope.Two nerves (one in Group A and another in Group B)were in the contusion zone,with moderate pathological changes.Conclusions The track of high velocity triangle fragments is unstable in the tissues.High disrupt rate,severe and wide extent lesion,early Wallerian degeneration are the main characteristics of direct injuries of swine's sciatic nerves.Indirect injuries can induce pathologic changes too,for which the lesion severity is related to the distance between nerves and primary wound tract.
ABSTRACT
Objective To analyze injury characteristics and treatment of hospitalized patients wounded in Wenehuan earthquake so as to provide references for medical rescue in disasters. Methods The study involved data of seismic patients from Trauma Database System Version 3.0 that collected clini-cal data of seismic patients admitted into West China Hospital of Sichuan University, Chengdu, and First and Second Hospitals of Deyang City. Trauma Database System Version 3.0 was developed by Research Institute for Traffic Medicine of PLA, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing. A comparative analysis was done on patient distribution, injury severity and medical treatment. Results There were 826 qualified patients including 410 males and 416 females ( at age range of 1-102 years, mean 45.8 years). Of all, the patients at age of 31-60 years accounted for 50. 2%. The patients were mainly peasants (43.8%, 208/477), workers (15.7%, 75/477) and students (14.1%, 67/477). Blunt injury (53.2%), crush/bury injury (22.5%) and slip/fall injury were three main causes for injury. The patients for 92.1% were admitted into two hospitals of the City of Deyang within four days after earthquake, while 81.7% of patients were admitted into West China Hospital in Chengdu at days 3-9 after earthquake. Patients with bone injuries accounted for 75.3%. The patients had abbreviated injury score (AIS) for mainly 1-3 points, with incidence rate of se-vere multiple trauma ( ISS > 16 points) of 8.2%. Internal fixation was done in 120 patients ( 34. 1% ), debridement and suturing in 103 (29.3%), external fixation in 55 ( 15.6% ), extremity amputation in 22 (6.3%) and intracerebral surgery in 2 (0.6%). Conclusions The injuries are mainly induced by collapse of buildings during earthquake. Bone injuries are predominant injury type, with AIS of mainly 1-3 points and few severe multiple trauma. The results show that the patients receive late special treat-ment and slow evacuation, indieating necessity of strengthening capacity of early medical treatment and ef-fective evacuation during destructive natural disasters.
ABSTRACT
Objective To observe the regulative effect of high dose of glucocorticoid (GC) on protein synthesis and mRNA transcription of corticotropin-releasing hormone (CRH) in paraventricular hypothalamic nucleus (PVN) so to ascertain whether there exists difference upon effect of GC either at high dose or at normal dose. Methods A total of 60 Wistar rats were divided into five groups, ie, blank control group, 10 -6 mol/L dexamethasone (DEX) group, 10 -9 mol/L DEX group, 9 g/L saline group and group that was treated with 10 -4 mol/L RU486 first and then with 10 -6 mol/L DEX. The drugs were given through femoral vein. CRH protein expression was measured by means of immunohistochemistry and laser confocal scanning microscophy (LCSM); CRH mRNA transcription level was investigated by in situ hybridization. Results There appeared positive CRH mRNA granules in cytoplasm of PVN after administration with 10 -6 mol/L DEX for 20 minutes but could be seen positive fluorescent granules of CRH protein 30 minutes later, which was reversed at an in advance blockage of GR, as was free in 10 -9 mol/L DEX group, 9 g/L saline group and blank control group. Conclusions High dose of GC can up regulate CRH gene expression in PVN and differs much from the traditional effect of GC at normal dose, as may be due to that high dose of GC exerts effects depending on membrane glucocorticoid receptor but normal dose of GC dose via iGR.
ABSTRACT
Objective To observe effect of the pulmonary injury and the dynamic changes of the blood gas index on the mortality rate of the dogs suffered from underwater blast injury. Methods 38 adult dogs were brought out underwater blast injury by TNT. The dogs that died on the spot were anatomized immediately, while the survivors were anatomized after 6 hours; the blood samples were taken before the explosions, 30min and 6 hours after them to analyze the blood gas index by i-STAT. Results Most of the lung injuries were pulmonary hemorrhage and edema; the positive impulse of the blast wave and the severity of the lung injury were closely related to the mortality rate; the frequency of the respiratory and the blood oxygen and the carbon dioxide pressure can roughly exhibit how severe the lungs were injured. Conclusions The severe hypoxia induced by lung injury is the main cause of the early death; correlation between the severity of the injury and the positive impulse of blast wave is very obvious.