海水浸泡爆炸伤延期植皮最佳时机的研究

目的确定海水浸泡爆炸伤延期植皮的最佳时机。方法建立海水浸泡爆炸伤动物模型后，分别于0、3、7、14d切取创面组织作病理切片，镜下观察创面受床的病理改变；同期对创区实施植皮术，通过计算机全自动图像分析系统准确计算出各组的皮片成活率。结果分别于伤后0、3、7、14d，对皮肤缺损区施行植皮术，发现不同时机植皮成活率不同，伤后7d对海水浸泡爆炸伤皮肤缺损区植皮，皮片成活率最高。结论海水浸泡爆炸伤延期7d后植皮是对创面实施植皮术的最佳时机。     

海水浸泡兔脑挫伤后caspase-8及caspase-3表达的研究

目的建立海水浸泡颅脑挫裂伤模型,观察海水浸泡对实验性脑挫裂伤后创伤性脑水肿的影响及研究兔脑挫伤后不同时间caspase-8及caspase-3表达的变化。方法采用立体定向自由落体伤模型进行持续海水浸泡作为实验组,对照组采用同样的方法致伤后不进行海水浸泡。观察创伤组织的病理改变,并通过免疫组化染色和计算机图像分析技术用半定量化的方法检测不同干预不同时程caspase-8和caspase-3的活性表达强弱差异。结果实验组和对照组均发生了创伤性脑水肿,但水肿高峰期出现时间不一致,严重程度也不一致。实验组caspase-8和caspase-3活性表达强度均高于对照组。结论海水浸泡促进了挫裂伤周边缺血水肿区神经细胞凋亡的增加。     

Effects of seawater immersion combined with open abdominal injury on the expression of NF-κB,and IκBαof small intestine in rats

Objective To observe effects of seawater immersion combined with open abdominal injury on the expression of NF-κB,and IκBαas well as the change pattern in rats. Methods Ninety-one Wistar rats were randomly divided into 3 groups: the control group (n =7), the open abdominal injury group(n =42) and open abdominal injury combined with 1-hour seawater immersion group ( n =42). The expression of NF-κB,andIκBαin small intestine tissues was measured by Western blot and statistical analyses were also made in the study. Results The expression of NF-κB,in the seawater immersion combined with open abdominal injury group increased significantly 3 hours after injury, when compared with that of the open abdominal injury group(P<0. 05), whereas the expression of NF-κB, of the pure injury group was slightly lower than that of the control group, but no statistical differences could be seen between them(P>0.05). The change pattern in the expression of IκBαwas quite the opposite to that of NF-κB. Conclusions NF-κB seemed to be rapidly and persistently involved in the whole inflammatory response to trauma induced by opened abdominal injury and seawater immersion, when a comparison was made with the pure open abdominal injury group. Injuries for the rats in the open abdominal injury combined with seawater immersion group were serious, and the feedback mechanism for NF-κB was not established for quite a long time.     

海水浸泡弹烧复合伤血细菌学与内脏病理学的变化

目的 探讨海水浸泡弹烧复合伤伤后血液细菌学变化与内脏病理学变化之间的关系。方法 建立海水浸泡弹烧复合伤模型后，依模型将15只成年杂种犬随机分为单纯弹烧复合伤组(简称非浸泡组，7只)和海水浸泡弹烧复合伤组(简称浸泡组，8只)，于伤后即刻和4、7、10、20、28h共6个时相点抽取静脉血进行血细菌培养。另于伤后28h和濒死期将动物活杀，取心、肝、肺、肾行病理学观察。结果 浸泡组动物菌血症出现较早且严重。导致菌血症的细菌来源复杂，不仅有肠道菌群，还有海水特有菌群和皮肤常驻菌群。在内脏器官组织病理学上，不仅有不同程度的血液循环障碍及退行性变，还有严重的炎症反应。结论 在海水浸泡弹烧复合伤中，伤后出现的严重菌血症进一步加重了内脏器官损伤。     

Thermal regulatory responses to submaximal cycling following lower-body cooling in humans

This study compared the effects of pre-exercise cooling with control water immersions on exercise-induced thermal loads derived from steady-state submaximal exercise. Eight healthy male participants [mean (SEM) age 29 (1) years, maximal oxygen uptake 3.81 (0.74) l·min^–1, and body surface area 1.85 (0.11) m²] took part in experiments that included 30 min of baseline data collection [ambient temperature 21.3 (0.2°C)], 30 min of immersion in water to the level of the supra-iliac crest [water temperatures of 35.1 (0.3)°C for thermoneutral and 17.7 (0.5)°C for precooled treatments], and 60 min of cycling exercise at 60% of maximal oxygen uptake. No significant differences were noted during exercise in net mechanical efficiency, metabolic rate, O₂ pulse, or ratings of perceived exertion between the two treatments. Precooling resulted in a significant negative body heat storage during immersion and allowed greater heat storage during exercise. However, net body heat storage for the entire protocol was no different between treatments. Cooling significantly lowered rectal, mean skin, and mean body temperatures as well as more than doubling the exercise time until a 0.5°C rectal temperature increase was observed. The cooling trial significantly delayed onset of sweating by 19.62 min and decreased sweat rate by 255 ml·h^–1 compared to control. Thermal and sweat sensation scores were lower after the cooling treatment compared to control. These data suggest that lower-body precooling is effective at decreasing body heat storage prior to exercise and decreases reliance on heat dissipation mechanisms during exercise. Therefore, this unique, well-tolerated cooling treatment should have a broader application than other precooling treatments. Electronic Publication     

Effects of sympathetic inhibition on blood pressure and renal responses to central hypervolaemia in normal humans

The purpose of this study was to evaluate the effects of short-term sympathetic inhibition with clonidine on blood pressure and renal responses to central hypervolaemia induced by thermoneutral head-out water immersion. Eleven healthy subjects were randomly studied on two occasions, during a 1 h pre-immersion period, 2 h of water immersion and a 1 h post-immersion period, after either placebo or clonidine treatment. Clonidine caused a significant suppression of plasma adrenaline, plasma noradrenaline, urinary noradrenaline excretion and mean arterial blood pressure. Blood pressure remained constant during water immersion after both placebo and clonidine, compared with the respective pre-immersion control values. The suppression pattern of plasma catecholamines and urinary noradrenaline in response to water immersion during placebo was similar after clonidine treatment. Renal volume excretion was not affected by clonidine. In contrast, clonidine caused a significant attenuation of the immersion-induced stimulation of natriuresis (maximum -33±12%, P<0.01, compared with placebo). These data indicate that the renal capacity to excrete sodium is impaired during moderate blood pressure reduction by short-term sympathetic inhibition with clonidine, whereas the regulation of arterial blood pressure in response to central hypervolaemia is maintained.     

犬胸部爆炸伤后海水浸泡的实验模型建立及早期救治结果分析

目的：建立犬海水浸泡胸部爆炸伤实验模型,探讨早期救治结果。方法：20只成年杂犬随机分为爆炸伤组（n=10)和锐器伤组（n=10)。两组动物均于致伤后浸泡在人工配制的海水中25min,而后打捞出海水环境后予以紧急救治。实验中全程监血液动力学呼吸系统和动脉血气变化。结果：海水浸泡后爆炸伤组的伤情明显重于脱器伤组,经救治后两组生存时间均明显延长,但锐器伤组更为明显。结论：本胸部爆炸伤模型是可行的并且重复性好,创伤后造成的呼吸循环功能变化与临床所见相符,适用于海水浸泡胸部开放伤的早期病理生理研究。爆炸伤的伤情更为严重,除严重电解质紊乱和高渗血症外,严重的肺损伤可能是影响生存时间的重要原因之一。     

海水淹溺性肺损伤机制的研究进展

溺水是重要的公共安全问题,是全球意外死亡三大原因之一。肺损伤是溺水患者最常见的并发症之一,其主要表现为严重的呼吸困难和低氧血症,近1/3的患者最终进展为急性肺损伤或急性呼吸窘迫综合症。肺泡上皮细胞是肺泡-毛细血管屏障重要组成部分,淹溺导致其结构和功能的完整性直接破坏促进了肺水肿的发生,同时肺毛细血管通透性增加,中性粒细胞和单核细胞等大量渗出聚集加剧肺内炎症反应。此外,机体氧化应激、细胞间连接和通讯等肺外机制也可导致肺损伤。本文就海水淹溺性肺损伤的相关机制研究进展进行了综述。     

海水淹溺肺水肿兔血浆MDA和SOD的变化

目的 :观察海水淹溺肺水肿 (PE SWD)兔血浆中丙二醛 (MDA)和超氧化物歧化酶 (SOD)变化规律 ,探讨上述两项指标发生变化的原因和机制。方法 :用核黄素光照法和硫代巴比妥酸法 ,对PE SWD兔动脉血浆MDA和SOD进行定量检测和动态观察。结果 :灌海水后 30min ,MDA和SOD较灌海水前均显著升高 ,尔后两者均逐渐下降 ,但仍远远高于灌海水前。结论 :PE SWD发生发展过程中 ,MDA的损害性作用使肺泡表面活性物质表面特性发生改变 ,影响了正常的呼吸功能 ,并掩盖了SOD的保护性作用。