Aquaporin-4 and traumatic brain edema

Brain edema leading to an expansion of brain volume has a crucial impact on morbidity and mortality following traumatic brain injury as it increases intracranial pressure, impairs cerebral perfusion and oxygenation, and contributes to additional ischemic injuries. Classically, two major types of traumatic brain edema exist： ＂vasogenic＂ and ＂cytotoxic/cellular＂. However, the cellular and molecular mechanisms contributing to the development/resolution of traumatic brain edema are poorly understood and no effective drugs can be used now. Aquaporin-4 （AQP4） is a water-channel protein expressed strongly in the brain, predominantly in astrocyte foot processes at the borders between the brain parenchyma and major fluid compartments,including cerebrospinal fluid and blood. This distribution suggests that AQP4 controls water fluxes into and out of the brain parenchyma. In cytotoxic edema, AQP4 deletion slows the rate of water entry into brain, whereas in vasogenic edema, AQP4 deletion reduces the rate of water outflow from brain parenchyma. AQP4 has been proposed as a novel drug target in brain edema. These findings suggest that modulation of AQP4 expression or function may be beneficial in traumatic brain edema.     

云母对大鼠慢性萎缩性胃炎干预及逆转治疗的机理探讨

目的 :研究云母对大鼠慢性萎缩性胃炎的干预及逆转治疗的机理。方法 :以 60%的乙醇 ,20mmol·L^-1的去氧胆酸钠和 0.1%的氨水在 24周建立SD大鼠慢性萎缩性胃炎模型。应用硫糖铝和2种剂量的云母进行干预及逆转治疗后 ,测定鼠胃黏膜细胞增殖带、血清表皮生长因子及生长激素水平。结果 :高、低云母干预组及高云母逆转组胃黏膜细胞增殖带与正常组接近 (P>0.05) ,而明显高于模型组 (P<0.01) ;低云母逆转组胃黏膜细胞增殖带低于正常组 (P<0.01) ,但高于模型组 (P<0.01)。高、低云母干预及逆转组血清表皮生长因子明显高于正常组 (P<0.01)及模型组 (P<0.05 ) ;而血清生长激素各组间无明显差别 (P>0.05)。结论 :云母干预及逆转治疗大鼠慢性萎缩性胃炎的作用与刺激内源性的表皮生长因子分泌、促进上皮增殖修复有关。     

微泵高浓度氯化钾溶液静脉注射抢救严重低钾血症的疗效观察

观察用微泵高 度氯化钾溶液静脉注射抢救严重低钾血症的疗效。方法：对３６例血钾低于２．５ｍｍｏｌ／Ｌ的患者用高 度（３％－５％，４０２ｍｍｏｌ／Ｌ－６７０ｍｍｏｌ／Ｌ）的氯化钾溶液，在心电监护下，２－３ｇ／ｈ用微泵大静脉补钾，直至血清钾达到正常值水平。结果：３６例患者在２－８ｈ内血清钾补充到３．５０ｍｍｏｌ／Ｌ，症状明显缓解，治愈率达１００％。结论：抢救严重低钾血症患者庆在心电监护下进行，用微泵高浓     

云母对大鼠慢性萎缩性胃炎的预防作用及机制研究

目的：研究云母对大鼠慢性萎缩性胃炎的预防作用并探讨其机制。 〖HTH〗方法：以60%的乙醇、20 mmol/L 的去氧胆酸钠和0.1%的氨水在24周建立SD大鼠慢性萎缩性胃炎模型。在造模的同时用云母进行预防实验。实验终期观察鼠胃黏膜大体观及各项病理学指标，并检测血清表皮生长因子和生长激素浓度。 〖HTH〗结果：云母预防组胃黏膜腺体排列规则，无明显的萎缩现象；胃窦部的胃黏膜炎症级别低于模型组（P<0.01）；胃黏膜腺体厚度(L1)和黏膜肌层厚度(L2)之比(L1/L2) 高于模型组（P<0.01）；单位长度内胃黏膜腺体数目高于模型组（P<0.01）。与正常组无明显差别（P>0.05）。胃窦部黏膜增殖细胞核抗原表达阳性的高度及血清表皮生长因子浓度高于模型组(P<0.01，P<0.05),而生长激素浓度与模型组无明显差别。 〖HTH〗结论： 云母对大鼠慢性萎缩性胃炎的形成有预防作用。减少损伤因子的破坏作用、促进胃黏膜细胞增殖及内源性的表皮生长因子分泌，可能是其重要作用机制。