The mechanisms of pathophysiological vasodilation or vascular hyporesponse

In some pathophysiological processes such as severe shock, the patients and animal experimental models fail to respond to pressor medicine. Vascular hyporesponse or vasodilation is one of the key problems in treatment of these patents. Although considerable progress had been made in recent years, the precise mechanisms of vascular contractile hyporeactivity have not been completely elucidated. A number of studies indicate that vascular hyporesponse or vasodilation correlate with many factors. In this review, the possible mechanisms about vascular hyporesponse or vasodilation during shock and other pathphysiolgoical processes were discussed.     

Effect of lansoprazole on gastric ulceration in rats

AIM:To investigate the effect of lansoprazole on gastric ulceration in rats. METHODS:Using the gastric ulcer model induced by hemorrhagic shock, restraint water-immersion stress and pylorus-ligature, the protective effect of lansoprazole (iv) on gastric ulceration was observed. RESULTS:Pretreatment with lansoprazole (7.5-60 mg/kg) significantly inhibited the formation of gastric ulcer in the three models in a dose-dependent manner. The autiulcer efficacy of lansoprazole was similar to that of omeprazole in the equal dose, but stronger than that of omeprazole for ulcer induced by water-immersion stress.CONCLUSION:The intravenously administered lansoprazole inhibited formation of experimental gastric ulcer in rats.     

Protective effects of diltiazem on liver,pancreas and small intestine in hemorrhagic-shock canine

AIM: To investigate the protective effects of diltiazem (Dil) on liver, pancreas and small intestines in hemorrhagic-shock canines and its mechanism. METHODS: The canines were bled to a mean arterial pressure (MAP) of 5.33-6.67 kPa for 30 min to produce the model of shock. During the shock, the dogs received water-soluble calcium channel blocker Dil or normal saline. The MAP was kept at the level for 90 min, then the total blood which was bled previously was reperfused. They were observed for 240 min. RESULTS: Dil could significantly elevated MAP of the hemorrhagic-shock canines (P<0.01) and the activity of superoxide dismmutase (SOD) of pancreas tissue (P<0.01), also it could decrease content of malondialdehyde (MDA) of the liver, pancreas and small intestine tissues (P<0.01). Electron microscope data indicated that Dil-treated dogs have a normal ultrastructure in the liver, pancreas and small intestine tissues. CONCLUSION: Dil can protect the structure and function of the liver, pancreas and small intestine in hemorrhagic-shock canines.     

汽车悬架参数优化的仿真研究

以BP神经网络对减振器的外特性进行建模为基础,Matlab/Simulink为工具,对汽车八自由度模型进行了平顺性仿真建模,并对含有不同神经网络减振器模型的整车振动响应输出进行了对比分析,从而找到适宜新车型的减振器,实现了汽车悬架阻尼参数的优化。     

Effect of Shenfu injection on hemodynamics of hypovolemic shock and oxygen delivery

AIM: To evaluate the effect of Shenfu injection on hemodynamics of hypovolemic shock patients and oxygen delivery by transesophageal Doppler echocardiography (Hemosonic 100 TM). METHODS: The transesophageal probe was placed in 32 patients with hypovolemic shock. 50 mL Shenfu injection were intravenously administered within 5 min. The parameters, including ABF, SVa, Acc, LVETi and TSVRa, were recorded at interval of 5, 10, 20, 30, 60 and 120 min. Meanwhile, MAP was measured at the same interval. Arterial and venous blood gases were taken at the beginning and 30, 60 and 120 min of the trial. DO2, VO2 and ERO2 were calculated. RESULTS: Acc, SVa, ABF increased while TSVRa decreased at 10 min after administration of Shenfu injection (P<0.01). DO2 and VO2 increased (P<0.01) and ERO2 decreased (P<0.05). CONCLUSION: Shenfu injection has a beneficial effect on hypovolemic shock by increasing cardiac output and improving oxygen delivery.     

Traumatic shock and systemic inflammation

Trauma is the No.1 cause of death in persons under the age of 45 and the No.3 cause of all deaths. Many trauma patients die of multiple organ failure (MOF), induced by systemic inflammatory response syndrome (SIRS). This paper reviews the relations of traumatic shock with systemic inflammation.     

Mesenteric lymph drainage alleviates spleen injury in hemorrhagic shock rats

AIM：To observe the effects of post-shock mesenteric lymph (PSML) drainage on histopathology, apoptosis, cell cycle and proliferation of the spleen in rats with hemorrhagic shock. METHODS：Eighteen Wistar rats were randomly divided into sham, shock and shock+drainage groups (n=6 in each group). The hemorrhagic shock model was established in the shock and shock+drainage groups. Fluid resuscitation for 30 min was performed 1.5 h after hypotension, and PSML was drained in the rats in shock+drainage group from 1 h after hypotension to 3 h after resuscitation finished. The fixed spleen tissue was harvested from each rat for histological observation with HE staining. The apoptosis of splenocytes was observed by Hoechst 33258 staining. The expression of Bcl-2 and Bax proteins was detected by immunohistochemical staining. The cell cycle and the expression of p53 protein were measured by flow cytometry, and the proliferation index (PI) was calculated. RESULTS：Compared with sham group, splenic tissue injury appeared in the shocked rats. The apoptotic cells and the expression of Bax and p53 in shock group were increased, while Bcl-2 expression was decreased. The percentage of G2/M cells in shock group was decreased. Compared with shock group, the splenic tissue damage in shock+drainage group was significantly attenuated. Moreover, the number of apoptotic cells, the percentage of G0/G1 cells, and the expression of Bax and p53 were obviously decreased, and the G2/M cells, Bcl-2 protein expression and PI were significantly increased in shock+drainage group. CONCLUSION: PSML drainage alleviates splenic injury in hemorrhagic shock rats, which may be related to reducing the apoptosis of splenocytes.     

农用车辆悬架系统的动态特性和减振器的性能试验

研究了车辆悬架系统的动态特性和减振器阻尼对其特性的影响。重点分析了农用运输车用气柱式减振器中气柱力的影响,得出了气柱弹簧刚度在减振器压缩和拉伸行程中的变化规律。指出如何利用上述规律和有关的性能试验获得阻尼系数或直接采用模拟实际工况的激振试验得出相应悬架系统的动态性能。