AIM: The influence of the seawater on the lipid peroxidation of the muscle tissue wounded by firearm was studied. METHODS: Both two limbs of rabbits were wounded by the steel ball of 250 mg. The wounded rabbits were divided into two group: One is seawater immersed group (SIG), which was dipped in artificial seawater for 30 min. Another is the single wounded group (SWG), which wasn't dipped in seawater. Then, muscle tissues 0.5 cm (A area), 1.5 cm (B area) and 2.5 cm (C area) from wound edge were cut for biochemical analysis at 3, 6, 12, 24 h of post-wound, respectively. The contents of ATP, MDA and SOD activity of all these tissues were detected, pre-wounded muscle tissues were used as control group. RESULTS: The content of MDA in SIG increased obviously at 3, 6 h, respectively, but it decreased slightly at 12 h and increased again at 24 h. The change in MDA in SWG is similar to that in SIG but more slightly. The changes in both the activity of SOD and the content of ATP in two groups is similar to that of MDA. CONCLUSION: Seawater induced more serious lipid peroxidation in the muscle tissue wounded by firearm.

AIM: The influence of the seawater on the lipid peroxidation of the muscle tissue wounded by firearm was studied. METHODS: Both two limbs of rabbits were wounded by the steel ball of 250 mg. The wounded rabbits were divided into two group: One is seawater immersed group (SIG), which was dipped in artificial seawater for 30 min. Another is the single wounded group (SWG), which wasn't dipped in seawater. Then, muscle tissues 0.5 cm (A area), 1.5 cm (B area) and 2.5 cm (C area) from wound edge were cut for biochemical analysis at 3, 6, 12, 24 h of post-wound, respectively. The contents of ATP, MDA and SOD activity of all these tissues were detected, pre-wounded muscle tissues were used as control group. RESULTS: The content of MDA in SIG increased obviously at 3, 6 h, respectively, but it decreased slightly at 12 h and increased again at 24 h. The change in MDA in SWG is similar to that in SIG but more slightly. The changes in both the activity of SOD and the content of ATP in two groups is similar to that of MDA. CONCLUSION: Seawater induced more serious lipid peroxidation in the muscle tissue wounded by firearm. [

Objective To evaluate the regional cerebral metabolic changes in different episodes by magnetic resonance spectroscopy (MRS) after explosive brain injury in rabbits. Methods Fortyfive New Zealand white rabbits were randomly divided into eight groups, ie, normal control group( 10 rabbits) and trauma group (35 rabbits). The explosive injury in trauma group was induced by explosion of 600 mg TNT equivalent of paper detonators at 6.5 cm above the rabbit brain. The rabbits in trauma group was divided into 1,6, 12, 24 hours, 3, 7, 14 days subgroups (6 rabbits per group). The survival rate was observed at different time points after explosive injury. The MRS was used to detect the regional cerebral metabolic changes including N-acetylaspartate (NAA)/creatine (Cr) ratio and choline(Cho)/Cr ratio as well as evolution of blast injuries over time. Results The rabbits survived for overseven days in the trauma groups, with typical brain contusion manifested by pathological and conventional MRI. Compared with the normal control group, the NAA/Cr ratio was markedly decreased at one hour after injury, slightly rose again at 24 hours and fell again after seven days. The Cho/Cr ratio was markedly increased at one hour after injury, slightly fell again at 12 hours and rose again at three days after injury.Conclusions MRS can manifest the regional cerebral metabolic changes of rabbits with explosive injury at different time points and hence provide a theoretical basis for understanding the local tissue changes and determining the type of tissue damage after blast injury.

ObjectiveTo evaluate the effect of high-frequency jec ventilation and bilevel positive airway pressure (BiPAP) ventilation in the severe dyspnea caused by central airway stenosis and explore the deferent application of two ventilation models.MethodsA retrospective analysis was designed to collect the serious dyspnea patients caused by central airway stenosis from January 2006 to January 2009.The patients were divided into group H and group B according to the different ventilation models,and the effect of relieving dyspnea and ameliorating hypoxemia was compared.ResultsSeven cases were in group H,and 9 cases were in group B.The therapeutic effect of relieving dyspnea was 14.29 ％(1/7) in group H.There were only 4 cases accepting high-frequency jec ventilation and the effect of relieving dyspnea was 25.00％(1/4).Two cases failed in high-frequency jec ventilation treatment and succeeded in BiPAP treatment thereafter,and 1 case failed in BiPAP treatment initially but was treated effectively by high-frequency jec ventilation after dyspnea relapsed.In group B,there were only 6 cases accepting BiPAP ventilation and the effect ofrelieving dyspnea was 83.33％ (5/6),and after adding the cases who accepting the sequential therapy of high-frequency jec ventilation and BiPAP ventilation the effect rate was 88.89％ (8/9).The difference had statistical significance(P =0.006).In ameliorating hypoxemia,the effect rate of group H was 100.00％ (7/7),of group B was 88.89％(8/9),and the difference had no statistical significance (P =0.563 ).Conclusions The high-frequency je ventilation is effective to relieve hypoxemia but is short of relieving dyspnea and subjective symptom,and it is suit for life support preoperative and intraoperative.The BiPAP ventilation is effective to relieve dyspnea and subjective symptom and hypoxemia,so the treatment effect is better than high-frequency jec ventilation,and it is suit in relieving symptom temporarily,pre-operative preparation and malignant tumor palliative treatment.

Objective　To investigate the surgical management of a gun shot wound of blood vessels and immersied, and evaluate its primary effect. Methods　100 rabbits were divided randomly into simple wounded group(SWG,n=50) and seawater immersion group(SIG,n=50).F emoral arteries were impacted by 0.38 gram steel spheres with velocity of 600 ～800 meters per second fired by 7.62 mm rifle. Animals in SIG were immersed in artificial seawater (pH 8.2～8.4, salinity 25.4,temperature 21℃) for 60 min, o f which those in SWG were spared. Grossly injuried artery was excised and restor ation of blood flow was reconstructed by end-to-end anastomosis or reversed au togenous venous grafting or cryopreserved arterial allografting. At 24 h,7,1 4,21 days after operation, blood flow was examined by Doppler ultrasonic detecti on and part of anastomotic sites and graft were collected for pathological obser vation. Results　In completely transected injury, the patency in SIG was 80.00%,while that in SWG was 86.67% in the first 3 weeks. In arterial c ontused injury ,patency in SIG was 86.67%,and that in SWG was 82.35% at the same time. Thrombosis occurred mostly in the first postoperative week. Atypical endo thelial cells were found at the anastomosis sites in the first postoperative week, and the anastomosis sites were lined with endothelium in 3 weeks postopera tively. Conclusion　Early curative effect could be obtained. Whe n grossly injuried artery is excised and followed by a routine surgical procedur e in the treating gunshot wounds immersed in seawater.

Objective　To provide experimental basis for the weapon design by means of observing the injury by super high velocity fragments. Methods　Nine male Huanan dogs were wounded by super high velocity aluminium bullet shot from an explosive gun with the energy of 15 360,12 643 and 8 144 J respectively, the degree of injury of local tissues and the pathological changes of main organs were observed. Results　The injury degree of local tissue wounded by the super high velocity fragment of 15 360 J was similar to that of 8 144 J, and was more severe than that of wound by 12 643 J. Conclusion　The injury degree is closely related to the mass and the momentum of the super high velocity fragment, the more the momentum is,the greater the execution is. No significant relationship exist between the injury degree and the energy.

Objective　To explore the characteristics of the changes of several metabolic and biochemical indices in dogs with both hindlimbs injured by kinetic weapon. Methods　12 animals were divided into 4 groups (Group Ⅰ, injured by regular weapon; Group Ⅱ,Ⅲ,Ⅳ injured by imitative kinetic weapons with different energy respectively). Levels of plasma Na+,Ca2+,K+ glucose, AMY, LDH, CK and serum T3,insulin,TSH were determined before and after injured. Results　①Local wounding conditions and distant organs' injuries in group Ⅱ,Ⅲ, and Ⅳ were more serious than those in group Ⅰ. ②Levels of plasma glucose in group Ⅱ,Ⅲ and Ⅳ were inereased significantly after injury than before(P<0.05), but not in group Ⅰ. Levels of Na+,Ca2+,K+,AMY,LDH in 4 groups had similar changes after injury while levels of CK in group Ⅱ,Ⅲ and Ⅳ were inereased significantly than that in group Ⅰ (P<0.05). ③After injury, levels of T3 in serum of all animals showed a decreased tendency and that of insulin decreased more significantly (P<0.05). There was no difference between every two groups. Levels of TSH in group Ⅱ,Ⅲ and Ⅳ were increased significantly after injured than before (P<0.05), but not in group Ⅰ. Conclusion　Not only local severe injury but also more serious injury in distant organs and more obvious changes of metabolic and biochemical indices can be induced by kinetic weapons than regular weapons.

Objective To investigate the effects of biatrial infusion on pulmonary artery pressure (PAP)after cardiopulmonary bypass (CPB) in patients undergoing mitral valve replacement.Methods Twenty NYHA Ⅱ or Ⅲ patients aged 22-53 yr weighing 34-57 kg undergoing mitral valve replacement complicated by pulmonary hypertension (mean pulmonary artery pressure (MPAP) ＞ 50 mm Hg) were randomly divided into 2 groups ( n = 10 each): infusion via right atrium group (group R) and infusion via both atria group (group B). After induction of anesthesia, a three cavity floating Swan-Ganz catheter was placed via right internal jugular vein to monitor CVP,PAP, pulmonary capillary wedge pressure (PCWP) and CO. The patients received infusion of prostaglandin E1 30-150 ng· kg- 1 · min - 1 and phenylephrine 0.2-0.6 μg· kg- 1 · min- 1 via central veins in group R and infusion of prostaglandin E1 30-150 ng·kg-1 ·min-1 via central veins and phenylephrine 0.2-0.6 μg·kg-1 ·min-1 via left atrium in group B. MAP, HR, MPAP, PCWP, CVP and CO were recorded 5 min before administration (T0), and 5,10, 30 and 60 min after administration (T1-4). Pulmonary vascular resistance index (PVRI), systemic vascular resistance index (SVRI) and CI were also calculated. Results D:\1111111111\MDB\zhmzxzz98201008.mdbCompared with the value at T0, MAP, MPAP, PCWP and PVRI were significantly decreased, while CI was increased at T1-4 in group R, and MAP, CI and SVRI were significantly increased, while HR, MPAP, PCWP, CVP and PVRI decreased at T1-4 in group B ( P ＜ 0.05).MAP, CI and SVRI were significantly higher, while HR, MPAP, PCWP, PVRI and CVP lower in group B than in group R ( P ＜ 0.05). Conclusion Biatrial infusion can effectively reduce PAP and pulmonary vascular resistance after CPB in patients undergoing mitral valve replacement.

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.

Objective　To observe the characteristics and rules of craniocerebral injury resulting from a high explosive shell to provide the bases for treating explosive injury. Methods　A total of 36 sheep were distributed at the distance 6 to 48 m away from the explosive center and the shell was exploded electrically at 7 m above the earth. At the same time, the velocity of fragments and shock wave pressure were determined. Gross and pathological observations were performed after injury. Results　Among all sheep with fragment injury, craniocerebral injury was 32%. Their immediate death rate was 75% and all died 6 h later. The incidence rates of penetrating wound and blind wound were 75% and 25% respectively. Pollution of wound track was heavy. The percentage of head lost was 50% in sheep and 50% of injured animal suffered from comminuted fracture of skull base. Bleeding was found extensively on the surface of the cerebrum, even medulla oblongata was involved. Hemorrhage, edema, rupture of small blood vessels and degeneration of neuron were found at the regions 4 cm away from the wound tract with light microscopy. Combined blast injury was found and occurred most often in the abdomen and limbs, both accounting for 62.5%, and combined thoracic injury was the third, up to 50%. All the animals of craniocerebral injury combined with lung blast injury. Conclusion　High explosive shells destroy cranium badly and extensively. Many skulls are lost and the cranial base is readily fractured. The wound track is heavily polluted. Combined injury is more often occurred.