BACKGROUND:Many studies have evaluated the role of vascular endothelial growth factor(VEGF) in traumatic brain edema and hemorrhagic brain edema. OBJECTIVE:To observe the effects of VEGF expression on permeability of ...BACKGROUND:Many studies have evaluated the role of vascular endothelial growth factor(VEGF) in traumatic brain edema and hemorrhagic brain edema. OBJECTIVE:To observe the effects of VEGF expression on permeability of the blood-brain barrier (BBB) during high-altitude and hypoxia exposure,and to investigate the correlation between VEGF expression and BBB permeability with regard to Evans blue staining and brain edema during high-altitude exposure. DESIGN,TIME AND SETTING:The randomized,controlled,animal study was performed at the Tanggula Etape,Central Laboratory of Chengdu Medical College,and Central Laboratory of General Hospital of Chengdu Military Area Command of Chinese PLA,China,from July 2003 to November 2004. MATERIALS:Quantitative RT-PCR kit(Sigma,USA),VEGF ELISA kit(Biosource,USA),and Evans blue(Jingchun,China) were acquired for this study. METHODS:A total of 180 Wistar rats were equally and randomly assigned to 15 groups:low-altitude (500 m),middle-altitude(2 880 m),high-altitude(4 200 m),super-high-altitude(5 000 m),1,3,5,7,9, 11,13,15,17,19,and 21 days of super high-altitude exposure.Wistar rats were exposed to various altitude gradients to establish a hypoxia model. MAIN OUTCOME MEASURES:Brain water content was calculated according to the wet-to-dry weight ratio.BBB permeability to Evans blue was determined by colorimetric method.VEGF mRNA and protein levels in brain tissues were detected using RT-PCR and double-antibody sandwich ELISA. RESULTS:Brain water content,BBB permeability to Evans blue,and VEGF mRNA and protein levels in brain tissues increased with increasing altitude and prolonged exposure to altitude.The greatest increase was determined on day 9 upon ascending 5 000 m.Simultaneously,VEGF expression positively correlated to BBB permeability of Evans blue and brain water content(r = 0.975,0.917,P<0.01). CONCLUSION:Increased VEGF protein and mRNA expression was responsible for increased BBB permeability,which may be an important mechanism underlying brain edema during high-altitude exposure.展开更多
Objective:To study the incidence and risk factors of hyperuricemia in young males who rapid entered into the plateau of 4500 m.Methods:The study contained 390 males aged 18-35 years(21.6±2.5 years),who rapidly en...Objective:To study the incidence and risk factors of hyperuricemia in young males who rapid entered into the plateau of 4500 m.Methods:The study contained 390 males aged 18-35 years(21.6±2.5 years),who rapidly entered the plateau with an altitude of 4500 m.According to their basic level of uric acid(UA),they were divided into two groups,high uric acid(HUA)group and normal uric acid(NUA)group.The characteristics and physiological index,such as the body weight and the height,of them were recorded.For the test of the biochemical indicators,the venous blood samples were collected at the altitude of 4500 m in the morning.The count of blood cells,blood urea nitrogen(BUN),serum creatinine(SCR),lactate dehydrogenase(LDH),total bilirubin(TBIL),direct bilirubin(DBIL)and indirect bilirubin(IDBIL)were compared between the two groups.Results:The incidence of hyperuricemia was 65.1%(254/390)at 4500 m.At the altitude of 4500 m,the mean hemoglobin concentration(MCHC)of red blood cells in the HUA group was significantly lower than that in the NUA group.Hemoglobin(HGB),mean red blood cell volume(MCV),TBIL,IDBIL,BUN,SCR and LDH in the HUA group were significantly higher than those in the NUA group,though without statistically significant differences in the other variables.Meanwhile,multivariate analysis showed at the altitude of 4500 m,the risk of HUA increased by 0.982,1.038 and 1.045 times when MCHC decreased by one unit and TBIL and SCR increased by one unit,respectively.Conclusion:The incidence of hyperuricemia was high of 65.1%rush entry into the plateau of young male.Decreased MCHC and elevated TBIL and SCR were independent risk factors for hyperuricemia when rapid enter into 4500 m.展开更多
基金Supported by:the Tackle Key Problem in Science and Technology during the "11~(th) Five-Year Plan" Period of Chinese PLA,No.06G030
文摘BACKGROUND:Many studies have evaluated the role of vascular endothelial growth factor(VEGF) in traumatic brain edema and hemorrhagic brain edema. OBJECTIVE:To observe the effects of VEGF expression on permeability of the blood-brain barrier (BBB) during high-altitude and hypoxia exposure,and to investigate the correlation between VEGF expression and BBB permeability with regard to Evans blue staining and brain edema during high-altitude exposure. DESIGN,TIME AND SETTING:The randomized,controlled,animal study was performed at the Tanggula Etape,Central Laboratory of Chengdu Medical College,and Central Laboratory of General Hospital of Chengdu Military Area Command of Chinese PLA,China,from July 2003 to November 2004. MATERIALS:Quantitative RT-PCR kit(Sigma,USA),VEGF ELISA kit(Biosource,USA),and Evans blue(Jingchun,China) were acquired for this study. METHODS:A total of 180 Wistar rats were equally and randomly assigned to 15 groups:low-altitude (500 m),middle-altitude(2 880 m),high-altitude(4 200 m),super-high-altitude(5 000 m),1,3,5,7,9, 11,13,15,17,19,and 21 days of super high-altitude exposure.Wistar rats were exposed to various altitude gradients to establish a hypoxia model. MAIN OUTCOME MEASURES:Brain water content was calculated according to the wet-to-dry weight ratio.BBB permeability to Evans blue was determined by colorimetric method.VEGF mRNA and protein levels in brain tissues were detected using RT-PCR and double-antibody sandwich ELISA. RESULTS:Brain water content,BBB permeability to Evans blue,and VEGF mRNA and protein levels in brain tissues increased with increasing altitude and prolonged exposure to altitude.The greatest increase was determined on day 9 upon ascending 5 000 m.Simultaneously,VEGF expression positively correlated to BBB permeability of Evans blue and brain water content(r = 0.975,0.917,P<0.01). CONCLUSION:Increased VEGF protein and mRNA expression was responsible for increased BBB permeability,which may be an important mechanism underlying brain edema during high-altitude exposure.
文摘Objective:To study the incidence and risk factors of hyperuricemia in young males who rapid entered into the plateau of 4500 m.Methods:The study contained 390 males aged 18-35 years(21.6±2.5 years),who rapidly entered the plateau with an altitude of 4500 m.According to their basic level of uric acid(UA),they were divided into two groups,high uric acid(HUA)group and normal uric acid(NUA)group.The characteristics and physiological index,such as the body weight and the height,of them were recorded.For the test of the biochemical indicators,the venous blood samples were collected at the altitude of 4500 m in the morning.The count of blood cells,blood urea nitrogen(BUN),serum creatinine(SCR),lactate dehydrogenase(LDH),total bilirubin(TBIL),direct bilirubin(DBIL)and indirect bilirubin(IDBIL)were compared between the two groups.Results:The incidence of hyperuricemia was 65.1%(254/390)at 4500 m.At the altitude of 4500 m,the mean hemoglobin concentration(MCHC)of red blood cells in the HUA group was significantly lower than that in the NUA group.Hemoglobin(HGB),mean red blood cell volume(MCV),TBIL,IDBIL,BUN,SCR and LDH in the HUA group were significantly higher than those in the NUA group,though without statistically significant differences in the other variables.Meanwhile,multivariate analysis showed at the altitude of 4500 m,the risk of HUA increased by 0.982,1.038 and 1.045 times when MCHC decreased by one unit and TBIL and SCR increased by one unit,respectively.Conclusion:The incidence of hyperuricemia was high of 65.1%rush entry into the plateau of young male.Decreased MCHC and elevated TBIL and SCR were independent risk factors for hyperuricemia when rapid enter into 4500 m.
