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find Keyword "Hypoxic" 14 results
  • Role of Vascular Endothelial Growth Factor in Protection on Intrahepatic Cholangiocyte Mediated by Hypoxic Preconditioning after Liver Graft

    Objective To investigate the protection on the intrahepatic cholangiocyte mediated by hypoxic preconditioning (HP) after liver transplantation and the role of vascular endothelial growth factor (VEGF). Methods The model of autologous liver transplantation was established, and the rats were divided into 3 groups: autologous liver transplantation group, hypoxic preconditioning before operation group (HP group) and sham operation group. At 6, 12, 24, 48 h after operation, blood samples were collected for examination of the serum total bilirubin (TBIL), direct bilirubin (DBIL) and alkaline phosphatase (ALP), and the expression of VEGF was detected by immunohistochemical method. The pathological changes of cholangiocytes were observed by light microscope. Results As compared with autologous liver transplantation group, the levels of seurm TBIL, DBIL and ALP in HP group were lower (P<0.05), while the expression of VEGF in HP group was higher at the whole process (P<0.05). The degrees of billiary epithelium damage and inflammatory infiltration in autologous liver transplantation group were more severe than those in HP group. Conclusion HP has protective effect on cholangiocytes after liver transplantation, in which VEGF may play an important role.

    Release date:2016-09-08 10:58 Export PDF Favorites Scan
  • Sex differences in learning and memory ability in hypoxic-ischemic brain injury in newborn mice

    ObjectiveTo investigate the effect of sex on learning and memory ability of newborn mice with hypoxic-ischemic brain injury.MethodsFifty C57BL/6 mice aged 10 days were divided into hypoxia-ischemia group and sham group according to the random number table method, and there were 28 in the hypoxic-ischemic group and 22 in the sham group with half female and half male respectively. In the ischemia-hypoxia group, the left common carotid artery was ligated and then the mice were placed in 34℃ hypoxia chambers with 8% oxygen and 92% nitrogen mixture for 45 minutes. In the sham group, only the skin of the left neck was cut and sutured. After 2 months, Y maze test and Morris water maze test were used to evaluate the learning and memory ability of mice.ResultsThe success rate of the hypoxic-ischemic group was 71.4% (20/28), and that of the sham group was 100.0% (22/22), a total of 42 mice were enrolled in the experiment. In Y maze test, there were differences in entries and total distance of new arms between the two groups (entries: F=16.068, P<0.001; total distance: F=8.532, P=0.007); compared between different groups in the same gender, the entries and total distance of new arms in the hypoxic-ischemic group were lower than those in the sham group with statistically significant differences (entries in males: P=0.001, entries in females: P=0.012; total distance in males: P=0.010, total distance in females: P=0.046). Compared between males and females in the same group, the entries and total distance of new arms of females were higher than those of males in the hypoxic-ischemic group, with statistically significant differences (P=0.039, 0.043). In Morris water maze test, the escape latency of positioning navigation in the hypoxic-ischemic group was higher than that in the sham group, and males showed more obviously poor performance (P<0.001); in the experiment of space exploration, differences were found in the duration of stay and the target quadrant entries between the two groups (duration of stay: F=8.297, P<0.001; entries: F=4.042, P=0.014), and there were statistically significant differences in the same gender males and females in the hypoxic-ischemic group and the sham group (duration of stay in males: P=0.003, duration of stay in females: P=0.038; entries in males: P=0.006, entries in females: P=0.041). Compared between males and females in the same group, the duration of stay and the target quadrant entries of females were higher than those of males in the hypoxic-ischemic group, with statistically significant differences (duration of stay: P=0.018; entries: P=0.032).ConclusionsThe learning and memory ability of newborn mice may be slightly impaired after hypoxic ischemic brain injury. There is significant difference in the effect on learning and memory ability between different genders, and the effect on males is higher than that on females.

    Release date:2020-02-03 02:30 Export PDF Favorites Scan
  • The Influence of Hypoxia Microenvironment on Metastasis Induced by Epithelial-Mesenchymal Transition of Human Lung Adenocarcinoma

    ObjectiveTo investigate the influence of hypoxia on pro-metastasis induced by epithelial-mesenchymal transition (EMT) of human lung adenocarcinoma. MethodsThe human lung cancer cell line H460 was cultured in hypoxic condition and the morphologic changes of the cells were observed under the microscope. The EMT-related markers including E-cadherin and vimentin were detected by Western blot. Transwell migration assay and transwell invasion assay were employed to detect the migratory and invasive activity of cancer cells. ResultsHypoxic induced morphological changes were consistent with the mesenchymal phenotype, such as an elongated fibroblastic morphology, and conversion from a tightly packed epithelial cobblestone pattern to a loosely packed scattered phenotype. Compared with the control group, hypoxic attenuated the quantity of E-cadhenrin, but increased vimentin, which resulted in promotion of migration and invasion of H460. ConclusionHypoxia induces EMT in H460 and enhances the invasive and migratory abilities of lung cancer cells.

    Release date:2016-10-21 01:38 Export PDF Favorites Scan
  • Study on serum lipoprotein in patients with chronic obstructive pulmonary disease complicated with pulmonary hypertension at middle and high altitudes

    Objective To investigate the effect of chronic altitude hypoxia exposure on serum lipoprotein levels in healthy subjects and patients with pulmonary hypertension, and whether there is a difference in serum lipoprotein levels between patients with pulmonary hypertension at middle and high altitude. Methods The case data of 245 Han patients with COPD complicated with pulmonary hypertension admitted to the Affiliated Hospital of Qinghai University from January 2018 to September 2022 were retrospectively analyzed. According to the altitude of their long-term residence before onset, the patients were divided into two groups, 119 cases in the middle altitude group (1500 m~2500 m). 126 cases were in the high altitude group of 2500 m~4500 m. In addition, the physical examination data of 50 healthy people in the intermediate and high altitude groups were collected as the control group (the age and gender of the healthy people in the same altitude group were similar to those in the COPD-PH group), a total of 4 groups were collected. The general data, pulmonary artery systolic blood pressure (PASP), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) of the four groups were compared, and the correlation between pulmonary artery systolic blood pressure (PASP) and related variables was analyzed. ResultsThere were no significant differences in age, gender, smoking and drinking between the healthy control group and COPD-PH group (all P>0.05). There were significant differences in body mass index, PASP, TC, TG, HDL-C, LDL-C, TG/HDL-C, HDL-C/LDL-C between the healthy control group and the COPD-PH group (all P<0.05). In the healthy control group, only BMI was significantly different between the high altitude group and the middle altitude group (P<0.05). In the COPD-PH group, PASP, BMI, TC, HDL-C and TG/HDL-C in the high altitude group were significantly different from those in the moderate altitude group (all P<0.05). There were no significant differences in age, gender, smoking, drinking, TG, LDL-C and HDL-C/LDL-C between the two groups (all P>0.05), when gender, age, altitude, body mass index, PASP, smoking and drinking were included in the multi-factor linear regression equation of lipoprotein (TC, TG, HDL-C and LDL-C), it was found that different elevations (middle and higher elevations) only had statistically different effects on HDL-C (b=-0.046, t=-2.209, P=0.028). Correlation analysis showed that PASP was not correlated with age, altitude, body mass index and blood lipids (TC, TG, HDL-C, LDL-C) in the healthy control group (all P>0.05). However, in the COPD-PH group, PASP was negatively correlated with blood lipid indicators (TC, HDL-C and LDL-C). PASP was positively correlated with altitude (a risk factor for hypoxia). ConclusionsHypoxia environment factors characterized by altitude are closely related to the severity of pulmonary artery pressure in patients with COPD-PH, and higher pulmonary artery systolic pressure is closely related to lower levels of TC, HDL-C and LDL-C.

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  • RESEARCH PROGRESS OF HYPOXIA INDUCIBLE FACTOR 1α IN HYPOXIC-ISCHEMIC INJURY

    To review the role of hypoxia inducible factor 1α (HIF-1α) in hypoxic-ischemic injury and its repair, and to analyze the possible mechanisms. Methods Recent l iterature on HIF-1α and its role in hypoxic-ischemic injury was reviewed and analyzed. Results HIF-1α was involved in the hypoxic-ischemic injury of various organs or tissues and their repair processes. Conclusion HIF-1α has a potential to treat common cl inical hypoxic-ischemic injuries and has a promisingfuture for appl ication.

    Release date:2016-09-01 09:07 Export PDF Favorites Scan
  • Effect of hypoxic preconditioning on rat lungs exposed to simulated high altitude hypoxia

    Objective To investigate the influence of hypoxic preconditioning on pulmonary structure of rats exposed to simulated high altitude hypoxia and to explore the role of hypoxia inducible factor-1α(HIF-1α).Methods Fifty-six Wistar rats were randomly divided into 7 groups(n=8 in each group),ie,a normal control group(N group),an acute hypoxic control group(H0 group),an acute hypoxic group(H1 group),a 3 000 m hypoxic preconditioning group(C3.0 group),a 3 000 m hypoxic preconditioning + acute hypoxic group (C3.1 group),a 5 000 m hypoxic preconditioning group(C5.0 group),and a 5 000 m hypoxic preconditioning + acute hypoxic group(C5.1 group).After treated with hypoxic preconditioning,the animals were exposed to simulated altitude of 6 000 m for 24 hours.Then the protein and mRNA expression of HIF-1α in lung of N,H0,C3.0 and C5.0 groups were assessed by Western blot and RT-PCR,respectively.The lung structure in N,H1,C3.1 and C5.1 groups was observed by light microscope and electron microscope.Results Pulmonary interstitial edema was apparently observed in H1 group,while significantly relieved in two hypoxic preconditioning groups.HIF-1α protein was not detected in rat lungs by Western blot analysis.Compared to N group,the levels of HIF-1α mRNA significantly increased in C3.0 group and C5.0 group(both Plt;0.01).Conclusions Hypoxic preconditioning can relieve hypoxic pulmonary interstitial edema and increase HIF-1α mRNA expression in rat lungs.HIF-1 may be involved in the process of hypoxic preconditioning in rat lungs.

    Release date:2016-09-14 11:56 Export PDF Favorites Scan
  • Fructose 1,6-Diphosphate in Hypoxic lschemic Encephalopathy:A Systematic Review

    Objective To assess the effectiveness and safety of fructose 1,6-diphosphate (FDP) in the treatment of hypoxic ischemic encephalopathy (HIE)patients. Methods Biomedical databases, including MEDLINE (1977 -2004 ), EMBASE(1989- 2004) ,Cochrane Injuries Group trials register, Cochrane Controlled Trials Register, CBMdisk and CNKI (1994- 2005 )were searched. Chnical trials were collecte&Quality assessments of chnical trials were carried out. Randomized controlled trials (RCTs) with mortality and the incidence of cerebral palsy, epilepsy and mental defect were selected for meta-analysis. Results Nine RCTs were included, and all were done in China. None of the 9 RCTs described the method of randomization or allocation concealment. None of the 9 RCTs mentioned wether blindness was use& In Jadad score, 5 trials were scored by 2 and 4 trials were 1. Seven trials were included in the meta-analysis of death, which showed that the obsolute risk (OR) [95% confidence interval (CI)] of death following FDP administration was 0. 50 (95% CI 0. 21 to 1.16). Five RCTs reported the results of follow-up. When intention to treat (ITT) analysis was adopted, the OR of FDP on cerebral palsy was 0. 36 (95% CI 0. 19 to 0. 89), on epilepsy was 0.74 (95% CI 0. 29 to 1.88), and on dementia was 0. 21 (95% CI 0. 06 to 0.70). We didn't conduct sensitivity analysis because no RCTs were of high quality. We didn't identify clinical trials compared with adverse reactions between the two groups. Conclusions The quality of RCTs on FDP for HIE is poor. Because there were no RCTs of high quality available, we can't draw a conlusion. Well-designed RCTs with economic evaluation are urgently needed to evaluate the value of FDP in the treatment of HIE.

    Release date:2016-09-07 02:26 Export PDF Favorites Scan
  • Hypoxic three-dimensional culture microenvironment promotes proliferation of bone marrow mesenchymal stem cells through HIF-1α signaling pathway

    ObjectiveTo investigate the effects of hypoxic three-dimensional culture microenvironment on the proliferation of bone marrow mesenchymal stem cells and its mechanism. MethodsP5 generation mouse bone marrow mesenchymal stem cells and P (3HB-co-4HB) were co-cultured under normoxic three-dimensional (20%) and hypoxic three-dimensional microenvironment (4%) respectively. After 24 hours, the proliferation of the two groups was determined by CCK-8 method. The expression of HIF-1α gene was detected by real-time quantitative PCR after 12 hours. Western blotting was used to detect the expression of HIF-1α protein after 24 hours. ResultsAfter 24 hours, the CCK-8 method showed that the OD value of the hypoxia group was significantly higher than that of the normoxia group (0.455±0.027 vs. 0.352±0.090, n=12, P<0.05). After 12 hours of hypoxic culture, the expression level of HIF-1α mRNA in the hypoxia group was significantly higher than that in the normoxia group (P<0.05). Compared with the normoxia group (0.47± 0.05), the relative expression level of HIF-1α protein in the hypoxia group (0.63±0.06) significantly increased in the Western blotting after 24 hours (n=3, P<0.05). ConclusionThe hypoxic three-dimensional microenvironment can promote the proliferation of bone marrow mesenchymal stem cells, which may be related to the activation of HIF-1α signaling pathway.

    Release date:2019-03-29 01:35 Export PDF Favorites Scan
  • Evaluation of Clinical Grading for Neonates with Hypoxic-ischemic Encephalopathy by Diffusion Weighted Imaging

    ObjectiveTo discuss the evaluation of clinical grading for neonates with hypoxic-ischemic encephalopathy (HIE) by diffusion weighted imaging (DWI). MethodsWe retrospectively analyzed the DWI findings of 39 neonates with HIE diagnosed by clinical criteria from December 2009 to July 2013. Abnormal signals were observed for 23 neonates (59%). These neonates were divided into three groups (group A, B and C) according to the shape and range of abnormal signals. Then Kappa test was performed between groups of different clinical grading (light, medium, severe). ResultsFor groups arranged based on abnormal signals and clinical grading, the Kappa value of the consistency test was 0.797 (P < 0.001). ConclusionsDWI negativity cannot exclude the existence of HIE. However, when abnormal signals occur, we can infer the severity in neonates with HIE according to the shape and range of abnormal signals by DWI.

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  • EFFECT OF INTEGRIN β8 ON NEURONAL APOPTOSIS AFTER HYPOXIA ISCHEMIA IN ASTROCYTE/NEURON CO-CULTURE SYSTEM

    ObjectiveTo observe the effect of integrin β8 on the neuronal apoptosis after hypoxia ischemia (HI) in astrocyte/neuron co-culture system. MethodsAstrocytes and neurons were cultured in vitro from cerebral cortex of the P1-3 days Sprague Dawley rats and E16 days fetal rats, respectively. Immunocytochemistry staining was used to identify the purity of cells. Integrin β8 mRNA expression was qualified in the astrocytes at 12 hours, 1 day, and 2 days after HI and reoxygenation (experimental group) and in normal astrocytes (control group) by RT-PCR. Integrin β8 small interering RNA (siRNA) system was established to specifically block astrocyte β8 expression, the efficiency of integrin β8 inhibition was detected by real-time fluorescent PCR. The astrocytes and neurons were co-cultured to established the astrocyte/neuron co-culture system. The neuronal apoptosis was detected with TUNEL in the normal neurons/astrocytes group (co-cultured HI group), the astrocytes infected by integrin β8 siRNA for 2 days/normal neurons group (β8 RNA interference group), and normal neurons in vitro with HI treatment group (HI group) at 1 day after HI and reoxygenation. The normal neurons without treatment as control (control group). ResultsGlial fibrillary acidic protein and neuronal nuclei staining suggested a purity of more than 90% in cultured cells. HI resulted in an increase of integrin β8 mRNA expression at 12 hours after reoxygenation in astrocytes, which peaked at 1 day after reoxygenation, then slowly decreased and remained higher at 2 days, showing significant differences between control group and experimental group and among different time points in experimental group (P<0.05). RNA interference efficiency was most significant at 2 days after astrocytes infected with integrin β8 siRNA (P<0.05). The neuronal apoptosis was significantly increased in HI group, co-cultured HI group, and β8 RNA interference group when compared with control group (P<0.05). But neuronal apoptosis index (AI) was significantly decreased in co-cultured HI group and β8 RNA interference group when compared with HI group (P<0.05). The significant difference of AI was found between co-cultured HI group and β8 RNA interference group (P<0.05). ConclusionIntegrin β8 expression can be induced with hypoxic-ischemic brain damage, leading to decreased AI of neurons and obvious protective effect.

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