目的 建立犬开放性气胸海水浸泡的实验模型 ,探讨实验动物早期死亡原因。 方法 2 0条健康成年杂种犬随机分为两组。对照组 :实验动物受伤后直接观察 ;实验组 :动物受伤后置入人工配制的海水中。监测血流动力学、呼吸、血液渗透压、血液电解质、动脉血气变化以及肺部病理改变。 结果 实验组死亡率明显高于对照组 ,平均生存时间为 45分钟。实验组经海水浸泡后有急性呼吸和循环功能衰竭、严重电解质平衡紊乱、高渗血症、重度肺损伤以及严重代谢性和呼吸性酸中毒。 结论 开放性气胸后海水浸泡可引起一系列严重的病理生理变化 ,其结果是导致实验动物早期死亡的重要原因。
To observe the effect of chitosan/alginate (CTS/ALG) dressings on wound immersed in seawater. Methods Twenty-five healthy SD rats weighing 250-300 g were used to establ ish skin wound model through cutting 1.8 cm circle-shaped wound along spine bilaterally. The left side served as experimental group, and the right side as control group. The wounds were immersed in the prepared artificial seawater for 1 hour, then the experimental group was treated with CTS/ALG dressings, while the control group was treated with sterile gauze. Gross observation was performed andwound heal ing time was recorded. At 3, 5, 7, 10 and 12 days after operation, 2 cm × 2 cm skin tissues including the wounds were removed and underwent HE staining and immunohistochemistry staining using Envision method. Histological change of wound and expression of EGF receptor (EGFR) and bFGF were observed. Results In the experimental group, wound inflammatory response was sl ight and incrustation shrinked faster, while the incrustation in the control group shrinked slowly. The wound heal ing time of the experimental group and the control group was (11.68 ± 0.57) and (12.51 ± 0.54) days, respectively, suggesting there was a significant difference between two groups (P lt; 0.05). In the experimental group, granulation tissue prol iferation, cell infiltration, collagen tissue prol iferation, wound shrinkage and epithel ization appeared at 3 days after operation; regularly l ined collagen tissue, complete epithel ization and occurrence of skin appendages were observed at 10 days after operation; complete wound heal ing was noted at 12 days after operation; while in the control group, at the corresponding time point, late cell infiltration and epithel ization were observed and granulation tissue with ulcer was noted. Immunohistochemistry observation: high expression of bFGF in vascular endothel ial cells and interstitial fibroblasts and high expression of EGFR in vascular endothel ial cells were observed in the experimental group at 3 and 5 days after operation, and their expressions were low at 7, 10 and 12 days after operation; while in the control group, there were no or low expression of bFGF and EGFR at the same time point. Conclusion CTS/ALG dressings can promote the heal ing of wound immersed in seawater, but its mechanism needsfurther study.
ObjectiveTo establish pig abdomen bullet wound model in seawater immersion condition and to analyze injury characteristics. MethodsTwenty Xishuangbanna pigs were randomly divided into seawater immersion group and control group,with 10 in each group.The left lower quadrant anti McBurney point of the pig semi-floating in the seawater was shot by using domestic 81-1 assault rifle at the distance of 10 meters,which were salvaged out of seawater at 60 minutes after injury in the seawater immersion group.The pigs in the control group were treated same as the seawater immersion group except seawater immersion.The mean arterial pressure (MAP),rectal temperature (RT),heart rate (HR),respiratory (R),white blood cell count (WBC),and C-reactive protein (CRP) were tested at 1 h,4 h,8 h after injury.The death of pig was observed. ResultsThe pig abdomen bullet wound models in the seawater immersion condition were successfully established.① Compared with the control group,the MAP and RT were significantly decreased at 1 h,4 h,8 h after injury,the HR or the R was significantly decreased at 4 h or 8 h after injury respectively in the seawater immersion group.② Compared with the normal value,the WBC obviously rose at 4 h and 8 h after injury,the CRP obviously rose at 1 h,4 h,and 8 h after injury in both two groups.Compared with the control group,the WBCs were significantly increased at 4 h and 8 h after injury (P<0.05),the CRPs were significantly increased at 1 h,4 h,and 8 h after injury (P<0.05) in the seawater immersion group.③ The mortality in the seawater immersion group (50%) was significantly higher than that in the control group (20%,P<0.05). ConclusionThe injury is more serious,the infection time is earlier,and the infection degree is aggravated,the mortality rate is higher for pig abdomen bullet wound model in seawater immersion condition.