Effects of orientation and distance of goats on blast lung injury characteristics on a plateau above 4500-meter / 中华创伤杂志(英文版)

PURPOSE@#High explosives are used to produce blast waves to study their biological effects. The lungs are considered as the critical target organ in blast-effect studies. The degree of lung hemorrhaging is related to both the explosive power and the increased lung weight. We studied the characteristics of the biological effects from an air explosion of a thermobaric bomb in a high-altitude environment and the lethality and lung injury severity of goats in different orientations and distances.@*METHODS@#Goats were placed at 2.5, 3, 4, and 5 m from the explosion center and exposed them to an air blast at an altitude of 4700-meter. A group of them standing oriented to the right side and the other group seated facing the explosion center vertically. The lung injuries were quantified according to the percentage of surface area contused, and using the pathologic severity scale of lung blast injury (PSSLBI) to score the 4 injury categories (slight, moderate, serious and severe) as 1, 2, 3, and 4, respectively. The lung coefficient (lung weight [g]/body weight [kg]) was the indicator of pulmonary edema and was related to lung injury severity. Blast overpressure data were collected using blast test devices placed at matching locations to represent loadings to goats. All statistical analyses were performed using SPSS, version 26.0, statistical software (SPSS, Inc., Chicago, IL, USA).@*RESULTS@#In total, 127 goats were involved in this study. Right-side-standing goats had a significantly higher mortality rate than those seated vertical-facing (p < 0.05). At the 2.5 m distance, the goat mortality was nearly 100%, whereas at 5 m, all the goats survived. Lung injuries of the right-side-standing goats were 1 - 2 grades more serious than those of seated goats at the same distances, the scores of PSSLBI were significantly higher than the seated vertical-facing goats (p < 0.05). The lung coefficient of the right-side-standing goats were significantly higher than those of seated vertical-facing (p < 0.05). Mortality, PSSLBI, and the lung coefficient results indicated that the right-side-standing goats experienced severer injuries than the seated vertical-facing goats, and the injuries were lessened as the distance increased. The blast overpressure was consistent with these results.@*CONCLUSION@#The main killing factors of the thermobaric bomb in the high-altitude environment were blast overpressure, blast wind propulsions and burn. The orientation and distances of the goats significantly affected the blast injury severity. These results may provide a research basis for diagnosing, treating and protecting against injuries from thermobaric explosions.

Finite element analysis on mechanical responses of human torso with body armor to non penetrating ballistic impact / 医用生物力学

ObjectiveTo develop a finite element computational model of the torso for the numerical simulation of mechanical responses of human torso to non-penetrating ballistic impact. MethodsBased on the CT data of a Chinese adult man, the finite element model of human torso was created by using the medical image processing software Mimics and the finite element pre-processing software HyperMesh. The pressure and acceleration response of the human torso outfitted with soft body armor to the ballistic impact from 9 mm ammunition at a velocity of 360 m/s was calculated numerically by the explicit finite element code LS-DYNA. ResultsThe finite element model of human torso including thoracic skeletal structure, organs, mediastinum and muscle/skin was established. The pressure response of heart, lung, liver and stomach, as well as the acceleration response of sternum were obtained by numerical calculation. It was found that the peak pressure and its time phase were dependent on the distance between the impact point and the measured point wherever in various organs or different position of an organ. Conclusions The finite element computational model of human torso outfitted with soft body armor is available for the simulation of human response to non-penetrating ballistic impact, and the simulated response can be used as evidence for the investigation on mechanism and protection of behind armor blunt frauma.

Pathological study of rabbits' femoral arteries subjected to gunshot wounds combining with seawater immersion / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate pathological characteristics of gunshot wounds concomitant seawater immersion in rabbits' femoral arteries.</p><p><b>METHODS</b>Thirty rabbits were divided randomly into 3 groups: simple gunshot-wound group (Group I, n = 10), gunshot wound with seawater immersion for 30 mins (Group II, n = 10), and 60 mins group (Group III, n = 10). Femoral arteries were impacted by 0.38 g steel spheres fired with a 7.62 mm rifle. After being wounded, rabbits in Groups II and III were immersed in seawater for 30 or 60 mins, but those in Group I were not. At 2, 4, 6, 8, 12 hours following injury, a 40 mm segment of the artery on each side of the gunshot point were excised and observed by light and electron microscopy.</p><p><b>RESULTS</b>The patterns of arterial injuries were mainly contusion and transection. Completely transected artery was classified as primary-wound-tract area, contused area and shocked area. Compared with those in Group I, the primary-wound-tract and contused areas in Group II manifested obvious swelling in the arterial wall especially at the outside 2/3 of the media. Vacuolar structures were often seen in smooth muscle cells of the media. Intercellular space among the smooth muscle cells were filled with homogeneous acidophilic substances. Deep rugae among endothelial cells flattened or rugal folds lost their longitudinal orientation, and marked fibrin and platelet deposition were noticed. No significant difference was detected between Group II and III. The pathological changes in the shocked area were similar in 3 groups.</p><p><b>CONCLUSIONS</b>For gunshot wounds concomitant seawater immersion in rabbits' femoral arteries, there was a marked swelling of cells and intercellular space in primary-wound-tract area and contusion area. The influence of these pathological changes on surgical reparation deservers further study.</p>

Surgical treatment for rabbits' femoral arteries subjected to gunshot wounds combining with seawater immersion / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the surgical treatment methods and evaluate the outcome of gunshot wounds combining with seawater immersion in rabbits' femoral arteries.</p><p><b>METHODS</b>One hundred healthy New Zealand white rabbits (either sex, 3.14 kg+/-0.61 kg in weight) were randomly divided into a seawater immersion group (n=50) and a simple injury group (n=50). The unilateral femoral arteries of all the rabbits were injured by 0.38 g steel spheres with velocity of 600-800 m/s fired by a 7.62 mm rifle. The rabbits in the seawater immersion group were immersed in seawater (saline content of 2.54%, pH 8.2-8.4, and at 21 degrees C) for 60 minutes but those in the simple injury group were not. After the injured segment (observed by naked eyes) of the femoral artery was excised, the blood flow restoration was reconstructed by direct end-to-end anastomosis, reversed autogenous venous grafting or cryopreserved arterial allografting, according to the length of the arterial defects. At 24 hours, and 7, 14 and 21 days after operation, the blood flow was examined. Operative exploration was performed for the animals with partly or fully obstructed blood flow. The tissues around the anastomosis sites and the grafts were harvested for pathological observation under a light microscope and an electron microscope.</p><p><b>RESULTS</b>In the rabbits with completely transected injury, the unobstructed rates in the first 3 weeks after operation were 80.00% in the seawater immersion group and 86.67% in the single injury group, and no significant difference was found between the two groups (P>0.1). In the rabbits with arterial contusion injury, the unobstructed rates in the first 3 weeks after operation were 86.67% in the seawater immersion group and 82.35% in the single injury group, and no significant difference was found between the two groups (P>0.1). Most thrombosis occurred in the first operative week. Atypical endothelial cells were detected at the anastomosis sites at the first operative week, and the anastomosis sites were lined with endothelial cells in 3 weeks postoperatively.</p><p><b>CONCLUSIONS</b>During the surgical treatment for gunshot wounds combining with seawater immersion, resection of the grossly-injured artery and routine artery reconstruction can obtain satisfactory outcome. Homologous artery is a kind of vascular graft with certain applied value.</p>

Identification of differentially expressed genes from spinal cord after firearm injury to rabbit sciatic nerves / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>Peripheral nerve regeneration depends on gene regulation by central neurons. To search for more effective treatment methods to improve the regeneration of wounded peripheral nerves, gene expression profile of spinal cord after firearm injury to rabbit sciatic nerves are studied with DNA micro-array technique.</p><p><b>METHODS</b>A total of 54 rabbits were randomly divided into 4 groups: Groups d1, d3, d7 and normal control group. Lumbar spinal cords were sampled. RNA and mRNA were extracted, labeled by Cy3 and Cy5, and analyzed by mouse_8192S gene chips.</p><p><b>RESULTS</b>A total of 1367, 923, and 61 genes with differential expression were found on day 1, day 3, and day 7 after trauma respectively. Five expressed sequence tag (EST) sequences demonstrated differential expression during 7 days after trauma.</p><p><b>CONCLUSIONS</b>There is complex gene profile with differential expression after firearm nerve injury, among which AW701496, U84291, W13926, X04017 and AW822394 EST sequences may be important regulation factors that involved in regeneration of peripheral nerve injury.</p>

Surgical management and its therapeutic effect of gunshot wounded femor al arteries immered in seawater in rabbits / 第三军医大学学报

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.

Observation on the craniocerebral injury of sheep by high explosive shell / 第三军医大学学报

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.

Study on the evaluation of the execution of super high velocity fragment / 第三军医大学学报

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.

Changes of several metabolic and biochemical indices of dogs with both hindlimbs injured by imitative kinetic weapon / 第三军医大学学报

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.

Surgical management and its therapeutic effect of gunshot wounded femor al arteries immered in seawater in rabbits / 第三军医大学学报

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.

Observation on the craniocerebral injury of sheep by high explosive shell / 第三军医大学学报

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.

Study on the evaluation of the execution of super high velocity fragment / 第三军医大学学报

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.

Changes of several metabolic and biochemical indices of dogs with both hindlimbs injured by imitative kinetic weapon / 第三军医大学学报

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.