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Acute kidney injury and acute lung injury/acute respiratory distress syndrome are common in the pediatric intensive care unit.Lung-kidney interaction in critically ill patients is closely related to anoxia, fluid management, and inflammatory response in acute kidney injury and acute lung injury/acute respiratory distress syndrome patients.Strengthening the understanding of lung-kidney interaction can help clinicians to systematically manage critically ill patients.
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The vascular endothelial cells (VECs) hypoxia/reoxygenation(H/R) model is a classic cell model that simulates vascular endothelial ischemia/reperfusion (I/R) injury and related diseases. It has the advantages of convenient operation, intuitive image, and good stability, and can accurately reflect pathological changes at the cellular level of diseases. It is widely used in the study of molecular mechanisms of drugs and diseases.There are many similarities in the mechanism and formation between the H/R model and the I/R injury model, but the I/R model is more complex. Therefore, in recent years, many scholars have used the H/R model to simulate the I/R model for experimental research, and believe that the H/R model is also an ideal model for studying I/R. By implementing intervention measures on the established H/R model of VECs, the potential effects of the intervention measures in clinical practice can be verified, which has guiding significance for how to prevent, treat, and how to exacerbate I/R injury in clinical practice. This article introduces the different methods used by scholars in recent years, such as medium deoxygenation and mixed gas culture method, to construct H/R models using VECs cultured in vitro to simulate I/R models. The differences in methods used and the subtle differences between the same methods are also discussed. At the same time, due to the relatively single method of constructing H/R models at present, how to find new, more efficient and affordable methods based on scientific and reasonable experiments has also become a focus of attention.
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Hypoxia is a common phenomenon of solid tumor, which is closely related to the malignant proliferation, tumor progression, radiotherapy and chemotherapy resistance, treatment failure, and poor prognosis. At present, many researches focus on the application of medical imaging and nuclear medicine methods in detecting the hypoxic areas of tumors. This article focuses on the detection of hypoxia microenvironment and the application of PET tracers in tumor hypoxia imaging.
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Objective To investigate the pathways by which hypoxia aggravates the neurotoxic effects of amyloid-beta protein (Aβ) on neurons.Methods Human neuroblastoma cells (SH-SY5Y cells) were cultured in vitro,and were divided into four groups:the control group,Aβ intervention group,hypoxia group,Aβ intervention plus hypoxia group.Quantitative real time polymerase chain reaction(qRT-PCR) was adopted to detect the mRNA expression levels of p21-activated kinase 1 (PAK1),LIM kinase 1 protein (LIMK1)and cofilin.Western blot was used to measure the protein levels of PAK1,LIMK1,phosphate-LIMK1 (P-LIMK1),cofilin and phosphate-cofilin (P-cofilin).Results After Aβ treatment,the activity of SH-SY5Y cells was decreased.Compared with the control group,the protein levels of PAK1,LIMK1,P-LIMK1,P-cofilin,and the mRNA expression levels of PAK1 and LIMK1 were decreased(all P＜0.05),but the protein and mRNA expression of cofilin had no significant changes after 24 h of treatment with 10μmol/L Aβ.Compared with the Aβ intervention group,the protein levels of PAK 1,LIMK1,P-LIMK 1 and P-cofilin were decreased (all P ＜ 0.05),and the mRNA expression levels of PAK1 and LIMK1 were decreased(both P＜0.05),but the protein and mRNA expression of cofilin had no significant changes after 24 h of treatment of SH-SY5Y cells with 10 μmol/L Aβ plus 2％ oxygen.Conclusions Aβ may reduce P-LIMK1 expression by inhibiting the activity of PAK1,thereby reducing the P-cofilin,increasing the formation of dephosphorylated cofilin,leading to neural cells damage,and hypoxia aggravates the neurotoxicity of Aβ through this pathway.
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Objective To study the effects of hypoxia on the expression of inflammatory factor high mobility group box-l(HMGB1) in the pulmonary arteriolae of neonatal SD rats.Method A total of 80 neonatal SD rats were randomly assigned into control group and hypoxia-induced persistent pulmonary hypertension of the newborn model (PPHN) group.The PPHN group was subdivided into 2 h,8 h,24 h,and 3 d post-PPHN subgroups according to the time of sacrifice.PPHN model was established on postnatal day 4 when rat pups in PPHN group were kept in low-oxygen box (10％ O2 and 90％ N2) for consecutively 7 days.Multi-channel physiological transducer RM-6280 was used recording the mean pulmonary artery pressure (mPAP) at the root to pulmonary artery of rat pups.ELISA method was used examining the serum level of HMGB1 of rat pups in each group.The pathology of the lung tissue was studied using optical microscope after HE staining,and MIAS-2000 medical image analysis software was used to calculate the ratio of the middle membrane thickness to the outer diameter of the pulmonary arteriolae wall (MT％).Protein level of HMGB1 in the lung was examined using Western Blot.Result The lung pathology in PPHN rats showed thickening of the middle membrane of the pulmonary arteriolae wall and stenosis of the pulmonary arteriolae.MT％ of control group and PPHN group were 5.3％ (3.7％,7.6％) and 7.1％ (4.6％,9.2％),respectively,without significant differences (P＞0.05).At 2 h,8 h,24 h,3 d post-PPHN timepoints,the serum levels of HMGB1 in PPHN group were (13.2±3.1),(15.4±3.6),(17.1±3.5),and (15.8±3.6) ng/ml,respectively,without intra-subgroup differences (F=2.134,P＞0.05),but significant differences existed when compared with control group at each timepoint (P＜0.01).Western Blot showed that HMGB1 protein expression in the lungs were significantly elevated soon after PPHN,peaked at 8～24 h,and reduced but still significantly elevated at 3 d after PPHN comparing with normal control.Significant differences existed at 2 h,8 h,and 24 h timepoints (P＜0.01,respectively).The HMGB1 protein of PPHN group declined significantly at 3 d timepoint without significant differences comparing with the control group (P＞0.05).Conclusion HMGB1 is closely related with the pathogenesis of PPHN,indicating the inflammatory response plays an important role in the mechanisms of PPHN.HMGB1 may be an indicator for the assessment of hypoxia-induced PPHN.
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Objective To explore the risk stratification of pulse oxygen saturation (SpO2) in patients with emergency hypoxemia patients, and to provide evidence for the identification of critical illness. Methods Self-designed clinical data registration form for patients with emergency hypoxemia , and prospective collection of 344 hypoxemia patients in the emergency department of Peking Union Medical College Hospital from March to April in 2018, including baseline data (name, gender, age, ID number, date, registration time), hospitalization method, past history, patient complaint and diagnosis, triage level, SpO2, whether to enter the rescue room, etc. Results All of 344 emergency hypoxemia patients, there were 163 cases (21.2% ) of ambulances, and 107 cases (31.1% ) of patients requiring immediate rescue. There were 54 cases (25.7%) and 53 cases (39.6%) in need of immediate rescue in day shift (8:00-20:00) and night shift (20:00-8:00 next day), with 9:00-10:00, 14:00-15:00, 20:00-24:00 in the majority. There was a statistical difference in the way of hospitalization, triage, and SpO(2 25.780, t=4.722, all P<0.05). SpO2 risk stratification was 0.905 in patients without pulmonary disease, and SpO2 risk stratification in patients with lung disease was 0.765. Conclusions Patients with hypoxemia account for a certain proportion in the emergency department and are in critical condition. The degree of critical condition of patients can be evaluated based on whether they have lung diseases, and the risk stratification of patients can be accurately determined with the help of SpO2, so as to further guide the hierarchical treatment measures for patients with emergency hypoxemia and rationally optimize the χ2=29.537, allocation of emergency resources.
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[Abstract] China has a vast territory and often needs workers in a special environment. Working and training in a special environment (such as high temperature, plateau anoxia, cold, long voyage, and so on) will put forward higher requirements for the body, and the body will also have adaptive changes. However, once the compensation range of the body is exceeded, there will be a series of discomfort and even pathological changes. A small number of literatures have described the major changes of the whole body under various special conditions, but there is still a lack of related summary of the metabolic changes, compensatory changes and pathological changes of kidney under various extreme environments. Therefore, the compensatory modification of the kidney and the possible causes of injury in various special environments have been summarized and analyzed in present paper, and combined with the related pathophysiological mechanism, the related protective measures of kidney have also been introduced.
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Objective@#To explore the risk stratification of pulse oxygen saturation (SpO2) in patients with emergency hypoxemia patients, and to provide evidence for the identification of critical illness.@*Methods@#Self-designed clinical data registration form for patients with emergency hypoxemia, and prospective collection of 344 hypoxemia patients in the emergency department of Peking Union Medical College Hospital from March to April in 2018, including baseline data (name, gender, age, ID number, date, registration time), hospitalization method, past history, patient complaint and diagnosis, triage level, SpO2, whether to enter the rescue room, etc.@*Results@#All of 344 emergency hypoxemia patients, there were 163 cases (21.2%) of ambulances, and 107 cases (31.1%) of patients requiring immediate rescue. There were 54 cases (25.7%) and 53 cases (39.6%) in need of immediate rescue in day shift (8:00-20:00) and night shift (20:00-8:00 next day), with 9:00-10:00, 14:00-15:00, 20:00-24:00 in the majority. There was a statistical difference in the way of hospitalization, triage, and SpO2 (χ2=29.537, 25.780, t=4.722, all P<0.05) . SpO2 risk stratification was 0.905 in patients without pulmonary disease, and SpO2 risk stratification in patients with lung disease was 0.765.@*Conclusions@#Patients with hypoxemia account for a certain proportion in the emergency department and are in critical condition. The degree of critical condition of patients can be evaluated based on whether they have lung diseases, and the risk stratification of patients can be accurately determined with the help of SpO2, so as to further guide the hierarchical treatment measures for patients with emergency hypoxemia and rationally optimize the allocation of emergency resources.
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Objective@#To investigate blood pressure and vascular remodeling of OSAS by establishing the chronic-intermittent hypoxia model in rat.@*Methods@#Experiments were performed on 35 adult male Sprague-Dawley rats. Animals were randomly divided into four groups: unhandled control group (with 5 rats in it), CIH group at 9/6/3 weeks (with 10 ratsin each group). Rats in CIH group went through 8-hour intermittent hypoxia everyday, and those in control group were raising normally. After 9-week experiment, blood pressure was measured. The changes of the following indexes were observed: pathological changes of aorta and the middle aorta thickness (HE staining), the collagen of aorta wall (Masson staining). The experimental data were analyzed by SPSS 24.0 statistical software. The variance was analyzed by one-way analysis of variance, and the irregularity was selected using the calibration t test.@*Results@#The systolic and diastolic blood pressures of the CIH9, 6, and 3 weeks groups and the control group were: (127±13) and (79±9), (124±11) and (81±7), (101±11) and (75±9), (91±10) and (65±9) mmHg (1 mmHg=0.133 kPa). The systolic blood pressure and diastolic blood pressure of the rats in the week of CIH 9 and 6 weeks were significantly higher than the control group (F=14.64, P=0.000; F=6.81, P=0.000). There was no significant difference in the mean blood pressure between the three groups of CIH and the control group. Membrane thickness in CIH9, 6 and 3 weeks and control group were: (20±2), (19±2), (14±2), (13±3) μm. Compared with the control group, the aortic pathology and thickness of the middle layer of the CIH9 and 6 weeks group were significantly thicker (F=20.24, P=0.000), but there was no significant difference between the CIH3 week group and the control group; the collagen deposition was unchanged compared with the control group.@*Conclusion@#Intermittent hypoxia for 6 weeks or more in rats resulted in the increasement of blood pressure, morphological changes of aorta and vascular remodeling in thickened media.
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Objective@#To understand the mechanism of chemotherapy resistance in nasopharyngeal carcinoma under hypoxic conditions through the perspective of protein SUMOylation modification.@*Methods@#Cobalt chloride (CoCl2) was used to establish the hypoxic model of human nasopharyngeal carcinoma CNE1 cells. Then, the cell cycle was detected by flow cytometry, and the expression level of small ubiquitin-related modifier(SUMO) and cyclin-dependent kinase 6 (CDK6) proteins were detected by western blotting. MTT assay was used to determine the median lethal dose (IC50) of cancer cells against cisplatin, and enzyme-linked immunosorbent assay (ELISA) was used to determine lactate dehydrogenase (LDH) level.@*Results@#The cell cycle of CNE1 induced by hypoxia was arrested in G0/G1 phase.The results of Western blot showed that the protein expression level of CDK6 in CNE1 cells was lower than that in the control group (0.83±0.25 vs. 0.43±0.21, t=14.67, P=0.003). The protein level of conjugated SUMO1 was significantly lower than that in the control group (2.69±0.48 vs. 1.38±0.31, t=17.22, P=0.001), while the level of free SUMO1 protein was significantly higher than that in the control group (2.01±0.43 vs. 2.60±0.59, t=15.45, P=0.002).The LC50 of CNE1 cells in the control group was significantly lower than that in the hypoxic group (29.44 μg/ml vs. 97.72 μg/ml, t=12.79, P=0.001). After CNE1 cells received 50 μg/ml cisplatin for 48 h, the LDH content in the supernatant of the control group was significantly higher than that in the hypoxic group ((541.49±64.59) ng/ml vs. (234.67±41.03) ng/ml, t=11.94, P=0.007)). The apoptosis rate of CNE1 cells in the control group was significantly higher than that in the hypoxic group ((76.64±5.37)% vs. (32.84±4.77) ng/ml, t=8.49, P=0.003)).@*Conclusion@#Hypoxia can dissociate the covalent modification of CDK6 and SUMO1, inhibit cell cycle and increase the chemotherapy resistance of nasopharyngeal carcinoma.
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Objective@#To explore the effects of transient receptor potential vanilloid 1 (TRPV1) on autophagy in early hypoxic mouse cardiomyocytes and the mechanism in vitro.@*Methods@#The hearts of 120 C57BL/6 mice aged 1-2 days, no matter male or female, were isolated, and then primary cardiomyocytes were cultured and used for the following experiments, the random number table was used for grouping. (1) The cells were divided into normoxia group and hypoxia 3, 6, and 9 h groups, with one well in each group. The cells in normoxia group were routinely cultured (the same below), the cells in hypoxia 3, 6, and 9 h groups were treated with fetal bovine serum-free and glucose-free Dulbecco′ s modified Eagle medium under low oxygen condition in a volume fraction of 1% oxygen, 5% carbon dioxide, and 94% nitrogen for 3, 6, and 9 h, respectively. The protein expressions of microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, TRPV1 were determined with Western botting. (2) The cells were divided into normoxia group and hypoxia group, with two coverslips in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above. The positive expression of TRPV1 was detected by immunofluorescence assay. (3) The cells were divided into 4 groups, with one well in each group. The cells in simple hypoxia group were treated with hypoxia for 6 h as above, and the cells in hypoxia+ 0.1 μmol/L capsaicin group, hypoxia+ 1.0 μmol/L capsaicin group, and hypoxia+ 10.0 μmol/L capsaicin group were respectively treated with 0.1, 1.0, 10.0 μmol/L capsaicin for 30 min before hypoxia for 6 h. The protein expressions of LC3, Beclin-1, and TRPV1 were detected by Western blotting. (4) The cells were divided into 5 groups, with 5 wells in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above, the cells in hypoxia+ chloroquine group, hypoxia+ capsaicin group, and hypoxia+ capsaicin+ chloroquine group were treated with hypoxia for 6 h after being cultured with 50 μmol/L chloroquine, 10.0 μmol/L capsaicin, and 50 μmol/L chloroquine+ 10.0 μmol/L capsaicin for 30 min, respectively. Viability of cells was detected by cell counting kit 8 assay. (5) The cells were divided into simple hypoxia group and hypoxia+ 10.0 μmol/L capsaicin group, with one well in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above, the cells in hypoxia+ 10.0 μmol/L capsaicin group were treated with 10.0 μmol/L capsaicin for 30 minutes and then with hypoxia for 6 h. The protein expressions of lysosomal associated membrane protein 1 (LAMP-1) and LAMP-2 were detected by Western blotting. Each experiment was repeated for 3 or 5 times. Data were processed with one-way analysis of variance, least significant difference t test, and Bonferroni correction.@*Results@#(1) Compared with those of normoxia group, the protein expressions of LC3, Beclin-1, and TRPV1 were significantly increased in cardiomyocytes of hypoxia 3, 6, and 9 h groups (t3 h=4.891, 5.890, 4.928; t6 h=9.790, 6.750, 10.590; t9 h=6.948, 6.764, 5.049, P<0.05 or P<0.01), which of hypoxia 6 h group were the highest (1.08±0.05, 1.12±0.10, 0.953±0.071, respectively). (2) The density of TRPV1 in cell membrane and inside the cardiomyocytes in hypoxia group was significantly increased with lump-like distribution, and the expression of TRPV1 was higher than that in normoxia group. (3) Compared with those of simple hypoxia group, the protein expression of Beclin-1 in cardiomyocytes of hypoxia+ 0.1 μmol/L capsaicin group was increased (t=10.488, P<0.01), while the protein expressions of LC3 and TRPV1 were increased without statistically significant differences (t=4.372, 3.026, P>0.05); the protein expressions of LC3, TRPV1, and Beclin-1 in cardiomyocytes of hypoxia+ 1.0 μmol/L capsaicin group and hypoxia+ 10.0 μmol/L capsaicin group were significantly increased (t=15.505, 5.773, 13.430; 20.915, 8.054, 16.384; P<0.05 or P<0.01), which of hypoxia+ 10.0 μmol/L capsaicin group were the highest (2.33±0.09, 1.34±0.07, 1.246±0.053, respectively). (4) Compared with 0.585±0.045 in normoxia group, the cardiomyocyte viability in hypoxia group was significantly decreased (0.471±0.037, t=4.365, P<0.05). Compared with that in hypoxia group, the cardiomyocyte viability in hypoxia+ chloroquine group was further decreased (0.350±0.023, t=6.216, P<0.01), while 0.564±0.047 in hypoxia+ capsaicin group was significantly increased (t=3.489, P<0.05). Compared with that in hypoxia+ chloroquine group, the cardiomyocyte viability in hypoxia+ capsaicin+ chloroquine group did not significantly change (0.364±0.050, t=0.545, P>0.05). (5) Compared with 0.99±0.04 and 0.54±0.04 in simple hypoxia group, the protein expressions of LAMP-1 and LAMP-2 in hypoxia+ 10.0 μmol/L capsaicin group were significantly increased (1.49±0.06, 0.81±0.05, t=12.550, 7.442, P<0.01).@*Conclusions@#TRPV1 can further promote the expression of autophagy-related proteins in hypoxic cardiomyocytes through autophagy-lysosomal pathway, enhance autophagy activity, and improve autophagic flow for alleviating early hypoxic cardiomyocyte injury.
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Objective@#To investigate the role of hexokinase Ⅱ in the changes of autophagic flow in cardiomyocytes of mice with ischemia-hypoxia in vitro.@*Methods@#The hearts of totally six male and female C57BL/6 mice aged from 1 to 2 days were isolated to culture primary cardiomyocytes which were used for the following experiments. (1) The cells were divided into 6 groups according to the random number table (the same grouping method below), i. e., normal control 3, 6, and 9 h groups and ischemia-hypoxia 3, 6, and 9 h groups, with 4 wells in each group. After being regularly cultured for 48 h with Dulbecco′s modified Eagle medium/nutrient mixture F12 (DMEM/F12) medium (the same regular culture condition below), the cells in normal control 3, 6, and 9 h groups were cultured with replaced fresh DMEM/F12 medium for 3, 6, and 9 h, respectively, and the cells in ischemia-hypoxia 3, 6, and 9 h groups were cultured with replaced sugar-free serum-free medium in the low-oxygen incubator with a volume fraction of 1% oxygen and a volume fraction of 5% carbon dioxide at 37 ℃ (the same hypoxic culture condition below) for 3, 6, and 9 h, respectively. Cell viability was measured by the cell counting kit 8 (CCK-8) method. (2) The cells were grouped and treated the same as those in experiment (1), with 1 well in each group. Western blotting was used to detect the protein expressions of microtubule-associated protein 1 light chain 3 Ⅰ (LC3Ⅰ), LC3Ⅱ, p62, and hexokinase Ⅱ. (3) The cells were divided into normal control group, simple ischemia-hypoxia 9 h group, and ischemia-hypoxia 9 h+ 2-deoxyglucose (2-DG) group, with 4 wells in each group. After a regular culture for 48 h, the cells in normal control group were cultured with replaced fresh DMEM/F12 medium for 9 h; the cells in simple ischemia-hypoxia 9 h group were replaced with sugar-free serum-free medium, and the cells in ischemia-hypoxia 9 h+ 2-DG group were replaced with sugar-free serum-free medium in which 2-DG was dissolved in a concentration of 10 mmol/L (20 μmol), and then they were cultured with hypoxia for 9 h. Cell viability was measured by CCK-8 method. (4) The cells were grouped and treated the same as those in experiment (3), with 1 well in each group. Western blotting was used to detect the protein expressions of LC3Ⅰ, LC3Ⅱ, and p62. (5) The cells were grouped and treated the same as those in experiment (3), with 2 wells in each group. Transmission electron microscope was used to observe autophagosomes/autolysosomes in cardiomyocytes. (6) The cells were divided into normal control group, simple ischemia-hypoxia 9 h group, ischemia-hypoxia 9 h+ hexosinase Ⅱ small interfering RNA1 (HK-ⅡsiRNA1) group, and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group, with 4 wells in each group. The cells in normal control group and simple ischemia-hypoxia 9 h group were regularly cultured for 48 h, and the cells in ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were respectively transfected with 200 nmol/L HK-ⅡsiRNA1 and HK-ⅡsiRNA2 and then also cultured for 48 h. The cells in normal control group were cultured with replaced fresh DMEM/F12 medium for 9 h, and the cells in simple ischemia-hypoxia 9 h group, ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group, and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were cultured with replaced sugar-free serum-free medium and hypoxia for 9 h. Cell viability was measured by CCK-8 method. (7) The cells were grouped and treated the same as those in experiment (6), with 1 well in each group. Western blotting was used to detect the protein expressions of LC3Ⅰ, LC3Ⅱ, p62, and hexokinase Ⅱ. Except for experiment (5), each experiment was repeated 3 times. Data were processed with one-way analysis of variance and lest significant difference t test, and Bonferroni correction.@*Results@#(1) The viabilities of cardiomyocytes in ischemia-hypoxia 3, 6, and 9 h groups were 0.450±0.022, 0.385±0.010, and 0.335±0.015, respectively, which were significantly lower than 0.662±0.026, 0.656±0.028, and 0.661±0.021 of the corresponding normal control 3, 6, and 9 h groups, respectively (t=6.21, 9.12, 12.48, P<0.01). (2) Compared with those of corresponding normal control 3, 6, and 9 h groups, the LC3Ⅱ/Ⅰ ratio and protein expressions of p62 and hexokinase Ⅱ in cardiomyocytes of ischemia-hypoxia 3, 6, and 9 h groups were significantly increased (t3 h=16.15, 10.99, 5.30, t6 h=6.79, 10.42, 9.42, t9 h=15.76, 16.51, 7.20, P<0.05 or P<0.01). (3) The viability of cardiomyocytes in simple ischemia-hypoxia 9 h group was 0.353±0.022, which was significantly lower than 0.673±0.027 of normal control group (t=9.29, P<0.01). The viability of cardiomyocytes in ischemia-hypoxia 9 h+ 2-DG group was 0.472±0.025, which was significantly higher than that of simple ischemia-hypoxia 9 h group (t=3.60, P<0.05). (4) Compared with those of normal control group, the LC3Ⅱ/Ⅰ ratio and protein expression of p62 in cardiomyocytes of simple ischemia-hypoxia 9 h group were significantly increased (t=9.45, 8.40, P<0.01). Compared with those of simple ischemia-hypoxia 9 h group, the LC3Ⅱ/Ⅰratio and protein expression of p62 in cardiomyocytes of ischemia-hypoxia 9 h+ 2-DG group were significantly decreased (t=4.39, 4.74, P<0.05). (5) In cardiomyocytes of normal control group, only single autophagosome/autolysosome with bilayer membrane structure was observed. Compared with that of normal control group, the number of autophagosome/autolysosome with bilayer membrane structure in cardiomyocytes of simple ischemia-hypoxia 9 h group was increased significantly. Compared with that of simple ischemia-hypoxia 9 h group, the number of autophagosome/autolysosome with bilayer membrane structure in cardiomyocytes of ischemia-hypoxia 9 h+ 2-DG group was significantly decreased. (6) The viability of cardiomyocytes in simple ischemia-hypoxia 9 h group was 0.358±0.023, which was significantly lower than 0.673±0.026 in normal control group (t=9.12, P<0.01). The viabilities of cardiomyocytes in ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were 0.487±0.027 and 0.493±0.022, respectively, which were significantly higher than the viability in simple ischemia-hypoxia 9 h group (t=3.63, 4.28, P<0.05). (7) Compared with those of normal control group, the LC3Ⅱ/Ⅰratio and protein expressions of p62 and hexokinase Ⅱ in cardiomyocytes of simple ischemia-hypoxia 9 h group were significantly increased (t=6.08, 6.31, 4.83, P<0.05 or P<0.01). Compared with those of simple ischemia-hypoxia 9 h group, the LC3Ⅱ/Ⅰ ratio and protein expressions of p62 and hexokinase Ⅱ in cardiomyocytes of ischemia-hypoxia 9 h+ HK-ⅡsiRNA1 group and ischemia-hypoxia 9 h+ HK-ⅡsiRNA2 group were significantly decreased (t=5.10, 7.76, 15.33, 4.17, 8.42, 12.11, P<0.05 or P<0.01).@*Conclusions@#Ischemia-hypoxia upregulates the expression level of hexokinase Ⅱ protein in mouse cardiomyocytes cultured in vitro, which decreases the viability of cardiomyocytes by impairing autophagic flow. To inhibit the activity of hexokinase Ⅱ or its expression can alleviate the ischemia-hypoxia damage of cardiomyocytes.
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Objective@#To investigate the protective effects and mechanism of keratinocyte growth factor (KGF) combined with hypoxia inducible factor-1α (HIF-1α) on intestinal crypt epithelial cells (IEC-6) of rats with hypoxia stress.@*Methods@#(1) The routinely cultured IEC-6 of rats were collected and divided into normoxia blank group, normoxia KGF group, normoxia HIF-1α group, and normoxia combine group, according to the random number table, and then the previous mediums were respectively replaced with dulbecco′s modified eagle medium (DMEM), medium with 0.5 ng/mL KGF, medium with 10.0 ng/mL HIF-1α, and medium with 0.5 ng/mL KGF and 30.0 ng/mL HIF-1α. And the cells were cultured in cell incubator with oxygen volume fraction of 21% for 24 hours. (2) Another batch of routinely cultured IEC-6 were collected and divided into normoxia control group, hypoxia control group, hypoxia KGF group, hypoxia HIF-1α group, and hypoxia combine group, according to the random number table. The previous mediums were replaced with DMEM, DMEM, medium with 0.5 ng/mL KGF, medium with 10.0 ng/mL HIF-1α, and medium with 0.5 ng/mL KGF and 30.0 ng/mL HIF-1α respectively. And then, the cells in normoxia control group were cultured routinely for 24 hours, and cells in the other 4 groups were cultured in cells incubator of 3 gases, with oxygen volume fraction of 5% for 24 hours. Cells cultured in normoxic and hypoxic incubators were collected, with 3 samples in each group, and morphological changes of cells were observed with optical microscope. Cells cultured in normoxic and hypoxic incubators were collected, with 3 samples in each group, and survival rates of cells were detected by cell count kit 8. Cells in normoxia control group and cells cultured in hypoxic incubator were collected, with 3 samples in each group. The cell cycle changes and apoptosis rates were detected by flow cytometer, the content of adenosine triphosphate (ATP) was detected by ultraviolet spectrophotometer, and protein expression of p53 was detected by Western blotting. Data were processed with one-way analysis of variance and least significant difference test.@*Results@#(1) After being cultured for 24 h, cells cultured in normoxic incubator grew well with oval or round shapes and clear cytoplasm, and cells cultured in hypoxic incubator showed irregular shapes such as fusiform or starlike shape, with black particle in cytoplasm. (2) After being cultured for 24 h, cell survival rates of normoxia blank group, normoxia KGF group, normoxia HIF-1α group, and normoxia combine group were (107.4±8.7)%, (109.8±2.9)%, (115.8±7.4)%, and (112.8±10.6)% respectively. There was no significantly statistical difference in general comparison of cell survival rates among the above groups (F=0.685, P=0.586). After being cultured for 24 h, cell survival rates of hypoxia control group, hypoxia KGF group, hypoxia HIF-1α group, and hypoxia combine group were (35.1±4.6)%, (52.9±6.8)%, (56.2±3.1)%, and (71.2±9.6)% respectively, which were significantly lower than (106.3±12.3)% of normoxia control group (P<0.001). Survival rates of cells in hypoxia KGF group, hypoxia HIF-1α group, and hypoxia combine group were significantly higher than the rate of cells in hypoxia control group (P=0.023, 0.009, <0.001). Survival rate of cells in hypoxia combine group was significantly higher than the rates of cells in hypoxia KGF group and hypoxia HIF-1α group (P=0.017, 0.045). (3) After being cultured for 24 h, percentage of cells in G1 phase in hypoxia control group was significantly higher than that of cells in normoxia control group (P=0.030), percentages of cells in S phase in hypoxia control group, hypoxia KGF group, and hypoxia HIF-1α group were obviously lower than the percentage of cells in normoxia control group (P=0.020, 0.031, 0.026), and percentages of cells in different phases in other groups were close to those of cells in normoxia control group (P=0.516, 0.107, 0.052, 0.985, 0.637, 0.465, 0.314, 0.591). After being cultured for 24 h, percentages of cells in G1 phase in hypoxia control group, hypoxia KGF group, and hypoxia HIF-1α group were obviously higher than the percentage of cells in hypoxia combine group (P=0.001, 0.030, 0.014), and percentages of cells in S phase in the above 3 groups were obviously lower than the percentage of cells in hypoxia combine group (P=0.001, 0.012, 0.010). (4) After being cultured for 24 h, compared with that of cells in normoxia control group, apoptosis rate of cells in hypoxia control group obviously increased (P=0.018), and apoptosis rate of cells in hypoxia combine group obviously decreased (P=0.008). After being cultured for 24 h, compared with that of cells in hypoxia control group, apoptosis rates of cells in hypoxia KGF group and hypoxia combine group obviously decreased (P=0.004, 0.001). Apoptosis rate of cells in hypoxia combine group was obviously lower than those of cells in hypoxia KGF group and hypoxia HIF-1α group (P=0.032, 0.002). (5) After being cultured for 24 h, compared with that of cells in normoxia control group, the content of ATP of cells in hypoxia combine group changed unobviously (P=0.209), and content of ATP of cells in the other groups obviously decreased (P= <0.001, 0.001, 0.002). Content of ATP of cells in hypoxia HIF-1α group and hypoxia combine group was obviously higher than that of cells in hypoxia control group (P=0.044, 0.001). Content of ATP of cells in hypoxia combine group was obviously higher than that of cells in hypoxia KGF group and hypoxia HIF-1α group (P=0.011, 0.020). (6) After being cultured for 24 h, protein expressions of p53 of cells in hypoxia control group, hypoxia KGF group, and hypoxia HIF-1α group were obviously higher than that of cells in normoxia control group (P<0.001), and protein expression of p53 of cells in hypoxia combine group was obviously lower than those of cells in hypoxia control group, hypoxia KGF group, and hypoxia HIF-1α group (P=0.001, 0.001, 0.002).@*Conclusions@#KGF combined with HIF-1α have significant protective effects on IEC-6 of rats with hypoxia stress, and can improve its survival in hypoxic environment by inhibiting cell cycle arrest, reducing the level of apoptosis, and increasing level of energy metabolism.
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Objective To evaluate the effect of dexmedetomidine on Src-mediated NR2A tyrosine phosphorylation in hippocampal neurons subjected to hypoxia-reoxygenation (H/R) in mice.Methods C57 mice at 18 days of gestation were sacrificed by pulling neck,fetal mice were obtained by caesarean section,and hippocampal neurons were isolated.Neurons were cultured in culture medium for 7 days and then divided into 3 groups (n =30 each) using a random number table method:control group (group C),H/R group and dexmedetomidine group (D group).Hippocampal neurons were exposed to 95％ N2-5％ CO2 in an incubator at 37 ℃ for 4 h followed by reoxygenation with 95％ O2-5％ CO2 for 24 h to establish the model of H/R.Dexmedetomidine was given at a final concentration of 1 μ mol/L,and neurons were incubated for 4 h before establishing the model.The viability of hippocampal neurons was measured by MTT assay,TUNEL staining was used to observe apoptosis in hippocampal neurons,and the expression of c-Src,phosphorylated Src Y416 (p-Src Y416),NR2A,phosphorylated NR2A Y1325 (p-NR2A Y1325) and cleaved caspase-3.was determined by Western blot.Apoptosis index was calculated.Results Compared with group C,the viability of hippocampal neurons was significantly decreased,apoptosis index was increased,and the expression of p-Src Y416,p-NR2A Y1325 and cleaved caspase-3 was up-regulated in group H/R (P＜0.05).Compared with group H/R,the viability of hippocampal neurons was significantly increased,apoptosis index was decreased,and the expression of p-Src Y416,p-NR2A Y1325 and cleaved caspase-3 was down-regulated in group D (P＜0.05).There was no significant difference in the expression of c-Src and NR2A among three groups (P＞0.05).Conclusion Dexmedetomidine can inhibit apoptosis in hippocampal neurons subjected to H/R,and the mechanism may be associated with decreasing Src-mediated NR2A tyrosine phosphorylation in mice.
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Objective To evaluate the efficacy of intermittent positive pressure ventilation (IPPV,1 ml/kg) of the operated lungs in preventing hypoxemia during one-lung ventilation (OLV) in elderly patients undergoing radical resection of esophageal cancer.Methods Sixty American Society of Anesthsiologists physical status Ⅰ or Ⅱ patients of both sexes,aged 65-75 yr,with body mass index of 18.5-24.0 kg/m2,were divided into 2 groups (n =30 each) using a random number table method:convention group and IPPV group.In convention group,ventilator settings were adjusted with the tidal volume of 6-8 ml/kg,respiratory rate of 15 breaths/min,inspiratory/expiratory ratio of 1 ∶ 2,and fraction of inspired oxygen 70％ during OLV.In IPPV group,ventilator settings were adjusted with the tidal volume of 1 ml/kg,respiratory rate of 15 breaths/min,and fraction of inspired oxygen 70％ on the operated side during OLV,and the ventilator settings on the other side were consistent with those previously described in convention group.Before anesthesia induction (T0),at 10 min of two-lung ventilation (T1),at 15,30 and 45 min of OLV (T2,4) and at 10 min after the end of OLV (T5),blood samples were collected from the radial artery for blood gas analysis.The partial pressure of arterial oxygen (PaO2) and alveolar to arterial partial pressure of oxygen were recorded.Respiratory index (RI) and oxygenation index (OI) were calculated.The occurrence of PaO2 ＜ 60 mmHg,RI＞ 1.0 and OI＜ 200 mmHg was recorded during OLV.Results Compared with convention group,the RI was significantly decreased at T4,the PaO2 and OI were increased,and the incidence of PaO2＜60 mmHg,RI＞ 1.0 and OI ＜ 200 mmHg was decreased in IPPV group (P＜ 0.05).Conclusion IPPV (1 ml/kg) of the operated lungs can prevent the occurrence of hypoxemia during OLV in elderly patients undergoing radical resection of esophageal cancer.
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Objective: To explore the influence of plateau environment in the development and morphology of the main organs of the offsprings of migrated rats, and to observe the pathological changes of heart, brain, and lung tissues of the offsprings of migrated rats. Methods: The 8-week Wistar rats who lived in the plain area were migrated to the plateau area. After 1 week, a total of 56 female and male rats were fertilized with a ratio of 3:1, and all the pregnant rats were natural childbirth. The offsprings rat pups were divided into three groups: 1 month, 3 months, and 6 months. Ten offsprings (5 female and 5 male) were randomly selected in each group to collect the heart, brain, lung, liver, kidney and other major organs to measure the weights. In each group, 45 offsprings were randomly selected to conduct water maze test, open field test and test of captive reaction. The brain, heart, and lung tissues from 5 offsprings in each group were collected for tissue section and the pathological changes of above organ tissues were detected with HE staining. Results: The pregnant rats moved from the plain to the plateau had normal feeding behavior, without preterm birth or death. On average, the pregnant rats had 8 to 10 babies per litter, with a total of 345 offsprings. The weight gain of offspring was about 1. 0-1. 5 g per day. Some of the offsprings had low intake and difficulty in foraging, and 15 offsprings died 3-5 d after birth, with a mortality rate of 4. 3%. The weight and the ratio of liver weight to body weight of the 6-month-old offsprings were increased compared with the 1-month-old offsprings (F0. 05). In open field test, there were 6 offsprings in open fieled test in 1-month old group showed a longer stay time in the central region than other rats (P0. 05). In spite of all the time points in the captive reaction experiment, all the animals behaved in a similar way. The HE staining results of myocardium tissue showed the myocardial inflammatory cell infiltration, venous congestion, nucleus disappearance, and visible cellular outline in the 1-3 month old offsprings and the myocardial vascular congestion and myocardial space enlargement in the 6-month-old offsprings. The HE staining results of brain tissue showed the glass body formation and nucleus disappearance in the 1-month-old offsprings and neuronal cell body deformation, blood vessel congestion and vacuolar degeneration in the 3-6-month-old offsprings. The HE staining results of lung tissue showed the thicker alveolar walls, lymphocyte and plasma cell infiltration, pulmonary capillary expansion and congestion in the 1-3-month-old offsprings and the thicker alveolar walls, lymphocyte and plasma cell infiltration, pulmonary capillary expansion and congestion, pulmonary interstitial edema and red blood cell liquefaction in the blood vessels in the 6-month-old offsprings. Conclusion: Tibetan plateau environment has an influence in the development and morphology of heart, brain and lung of the migrated rats, and the reason may be related to low pressure and hypoxia of plateau.
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It is an important clinical subject to illuminate the mechanisms of myocardial damage in the early stage post severe burn in prevention against and treatment of burn shock, which may offer a targeted " dynamic support" in the treatment of severe burn patients. In recent years, the role of autophagy in hypoxic myocardial injury has attracted much attention. Autophagy is a physiological phenomenon on intracellular digestion process of long-life proteins and the aging and damaged organelles through lysosomal system, and it is essential for maintaining the homeostasis of cells. Severe hypoxia/ischemia causes lysosome dysfunction, insufficient fusion between autophagosome and lysosome, accumulation of autophagosomes, and damaged autophagy flux, thus leading to cell dysfunction and cell death. To study the roles of autophagy and explore the potential signals in autophagy modulation will provide a new therapeutic target for alleviating cardiac dysfunction following severe burn.
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Objective To study the changes of intracellular calcium ion concentration in pulmonary artery smooth muscle cells (PASMCs) of hypoxic-induced persistent pulmonary hypertension (PPH) induced by calcium-sensitive receptor (CaSR) in a newborn mouse model.Method Ninety-six newbom C57BL/6 mice were randomly divided into control group,PPH group,PPH + agonist group and PPH + inhibitor group,with 24 mice in each group.The PPH model was induced by 12％ oxygen for 14 days.In the beginning,intraperitoneal injection of CaSR agonist (GdCl3) and CaSR inhibitor (NPS2390) were performed to mice in PPH + agonist group and PPH + inhibitor group respectively daily.After 14 days of modeling,pulmonary artery smooth muscle cells (PASMCs) of all four groups were cultured in vitro.Changes of Ca2+ fluorescence intensity in PASMCs of the four groups were detected by laser confocal microscope continuously.Result The ratio of pulmonary small vascular wall thickness to the vascular diameter and right ventricle/left ventricular thickness in PPH group were greater than those in the control group [(21.1％ ±1.8％) vs.(27.0％ ±0.9％),(0.62 ±0.22) vs.(0.83±0.45)],the differences were statistically significant (P ＜ 0.05),which imply that PPH mouse model was constructed successfully.The average Ca2+ fluorescence intensity in PASMCs of control group,PPH group,PPH + agonist group and PPH+ antagonist group were 122.5 ± 3.0,2 058.8 ±46.3,2 286.6 ±51.4 and 1 134.8 ± 8.5,respectively.The average Ca2+ fluorescence intensity in PASMCs of the PPH group,PPH + agonist group and PPH + antagonist group was higher than that of the control group respectively,the average Ca2+ fluorescence intensity in PASMCs of PPH group was higher than that of PPH + antagonist group,the differences were statistically significant (P ＜ 0.05).Whereas the difference of average Ca2 + fluorescence intensity in PASMCs of PPH group and PPH + agonist group was of no statistical significance (P ＞ 0.05).Conclusion CaSR may be involved in the occurrence and development of hypoxic-induced PPH in neonatal mice by affecting the intracellular Ca2+ concentration in pulmonary artery smooth muscle cells.
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High altitude environment is a special ecological environmental system. The specificity of this environment is the main reason of gastrointestinal reaction caused by acute exposure to high altitude. With the development of economy, more and more people come to the plateau,and gastrointestinal reaction caused by acute exposure to high altitude has attracted wide attention by scholars. This article briefly reviewed the mechanism of intestinal mucosal injury induced by acute exposure to high altitude.
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Objective To observe the protective effect of hydroxysafflor yellow A(HSYA) on anoxia/reoxygenation (A/R) injury of neonatal primary cardiomyocytes, and its relationship with phosphoinositide 3-kinase/protein ki-nase B/glycogen synthase kinase 3β(PI3K/Akt/GSK3β) signaling pathway. Methods Primary cardiomyocytes of neonatal rats were isolated from the rats and incubated for 48 hours. The cells were adhered to each other and then divided into five groups:control group (Con group), anoxia/reoxygenation group (A/R group),HSYA treatment group(A/R+H group),PI3K inhibitor (LY294002)treatment group(A/R+L group)and HSYA+LY294002 treat-ment group (A/R+H+L group),then to collect the supernatant fluid of each group to measure LDH.The flow cy-tometry was used to measure the apoptotic cells. The protein levels of Bcl-2,Bax,Akt,p-Akt (Ser473),GSK3β, p-GSK3β (Ser9) were evalated by Western blot. Results A/R increased LDH release,the apoptosis rate (P<0.001),and the expression of pro-apoptotic protein Bax (P <0.001) with the decrease of anti-apoptotic protein Bcl-2,p-Akt(Ser473), p-GSK3β(Ser9)(P<0.001) as compared with the control group. HSYA treatment de-creased LDH release,the apoptosis rate (P<0.001),and the expression of Bax (P<0.001) and increase the ex-pression of Bcl-2,p-Akt(Ser473),p-GSK3β(Ser9)(P<0.001). Compared with the A/R+H group,the expres-sion of Bax was increased (P<0.001),while the expression of Bcl-2, p-Akt(Ser473), p-GSK3β(Ser9)was de-creased (P<0.001) in the A/R+H+L group. Conclusions HSYA protects rats'cardiomyocytes from anoxia/reoxy-genation injury by regulating PI3K/Akt/GSK3β signaling pathway.