[A cross-sectional study of prevalence of chronic kidney disease and related factors in adults in Anhui province].

Objective: To understand the prevalence of chronic kidney disease (CKD) and related factors in adults in Anhui province based on the data of Chinese Chronic Diseases and Nutrition Surveillance program (2018) in Anhui. Methods: Multi-stage stratified cluster random sampling was used to select participants aged ≥18 years. Moreover, questionnaire survey, body measurements and laboratory tests were conducted. The complex weighting method was used to estimate the prevalence of CKD in residents with different characteristics, and complex sampling data logistic regression model was used for multivariate analysis to identify related risk factors. Results: A total of 7 181 participants were included. The overall prevalence of CKD was 11.06% in adults in Anhui, and the prevalence was 12.49% in women and 9.59% in men (P<0.05). The moderate, high and very high risk for CKD progression were 8.66%, 2.02% and 0.38%, respectively. Multivariate analysis showed that age (OR=1.03, 95%CI: 1.00-1.05), BMI (OR=1.05, 95%CI: 1.01-1.09), being woman (OR=1.38,95%CI: 1.22-1.55), hypertension (OR=2.50, 95%CI: 1.76-3.56), diabetes (OR=2.28, 95%CI: 1.51-3.43), dyslipidemia (OR=1.26, 95%CI: 1.11-1.43) and hyperuricemia (OR=2.16, 95%CI: 1.68-2.78) were risk factors for CKD. Conclusion: The prevalence of CKD in adults in Anhui was relatively high and age, gender, BMI, hypertension, diabetes, dyslipidemia and hyperuricemia were found to be associated with the prevalence of CKD. To prevent CKD and its complications, attention should be paid to the management of related risk factors, including overweight and obesity, hypertension, diabetes, dyslipidemia and hyperuricemia.

[Effects of bio-strength electric field on the motility and CD9 expression of human epidermal cell line HaCaT and mouse epidermal cells].

Objective: To investigate the regulatory effect of bio-strength electric field (EF) on the motility and CD9 expression of human epidermal cell line HaCaT and mouse epidermal cells. Methods: The experimental research method was used. Human immortal epidermal cell line HaCaT cells in logarithmic growth phase and primary epidermal cells isolated from 16 BALB/c mice (no matter male or female) aged 1-3 days were used for experiments. HaCaT cells were divided into EF group treated for 3 h at the EF intensity of 200 mV/mm and sham EF group with simulated treatment. The cell migration (direction, displacement velocity, and trajectory velocity, with 46 samples in EF group and 34 samples in sham EF group) and arrangement were observed in the living cell workstation, and the distribution and expression of CD9 protein were detected by immunofluorescence method. Both HaCaT cells and mouse epidermal cells were divided into sham EF group (simulated treatment) and EF groups treated respectively for 3 h at the corresponding EF intensity of 50, 100, 200, and 400 mV/mm. Both HaCaT cells and mouse epidermal cells were divided into blank control group without any treatment, and 1 h group, 3 h group, and 6 h group treated with EF at the intensity of 200 mV/mm for corresponding time respectively. The expression of CD9 protein was detected by Western blotting (n=3). Data were statistically analyzed with Mann-Whitney U test, one-way analysis of variance, independent sample t test and least significant difference test. Results: Within 3 hours of treatment, HaCaT cells in EF group tended to move towards the negative electrode obviously, while HaCaT cells in sham EF group moved randomly around the origin; compared with those of sham EF group, the directivity of HaCaT cells in EF group was significantly enhanced, and the displacement velocity and trajectory velocity were significantly increased (Z=-3.975, -6.052, -6.299, P<0.01). After 3 hours of treatment, the long axis of HaCaT cells in EF group was perpendicular to the direction of EF, while HaCaT cells in sham EF group arranged randomly. After 3 hours of treatment, the expression of CD9 protein in HaCaT cells in EF group was significantly down-regulated compared with that of sham EF group (t=4.527, P<0.01), although both expressed on cytomembrane. After 3 hours of treatment, the expression of CD9 protein in HaCaT cells and mouse epidermal cells in sham EF group, 50 mV/mm group, 100 mV/mm group, 200 mV/mm group, and 400 mV/mm group were 0.332±0.021, 0.283±0.032, 0.254±0.020, 0.231±0.041, 0.212±0.031 and 0.565±0.021, 0.453±0.022, 0.389±0.020, 0.338±0.021, 0.233±0.011, respectively. For both types of cells, compared with that of sham EF group, the expression of CD9 protein in cells was significantly decreased in the four groups of EF treatment (P<0.01); compared with that of 50 mV/mm group, the expression of CD9 protein in cells was significantly decreased in the other three groups of EF treatment (P<0.01); compared with that of 100 mV/mm group, the expression of CD9 protein in cells was significantly decreased in 200 mV/mm group and 400 mV/mm group (P<0.01); compared with that of 200 mV/mm group, the expression of CD9 protein in cells was significantly decreased in 400 mV/mm group (P<0.01). The expression levels of CD9 protein in HaCaT cells and mouse epidermal cells in blank control group, 1 h group, 3 h group, and 6 h group were 0.962±0.031, 0.784±0.020, 0.531±0.021, 0.409±0.011 and 0.963±0.031, 0.872±0.031, 0.778±0.040, 0.591±0.041, respectively. For both types of cells, compared with that of blank control group, the expression of CD9 protein in cells was significantly decreased in 1 h group, 3 h group, and 6 h group (P<0.01); compared with that of 1 h group, the expression of CD9 protein in cells was significantly decreased in 3 h group and 6 h group (P<0.05 or P<0.01); compared with that of 3 h group, the expression of CD9 protein in cells was significantly decreased in 6 h group (P<0.01). Conclusions: The bio-strength intensity EF can induce the directional migration and arrangement of HaCaT cells and down-regulate the expression of CD9 in HaCaT cells and mouse epidermal cells in a time-dependent and intensity-dependent manner.

[Retrospective study on the characteristics of early organ injury in elderly patients with severe burns].

Objective: To analyze the clinical characteristics of early organ injury in elderly patients with severe burns and the effects on the prognosis of patients. Methods: From January 2010 to August 2018, 62 patients with severe burns (43 men and 19 women, aged from 60 to 89 years at the time of admission) who were hospitalized in the Institute of Burn Research of the First Affiliated Hospital of Army Medical University (the Third Military Medical University, hereinafter referred to as the author's affiliation), meeting the inclusion criteria, were included in elderly (E) group, and 124 patients with severe burns (86 men and 38 women, aged from 18 to 59 years at the time of admission) at the same term were included in young and middle-aged (YM) group. Treatment of patients in the 2 groups followed the conventional procedures of the author's affiliation. The following data of patients in the 2 groups were retrospectively analyzed. (1) Fluid replacement volume and urine volume within the first and second post injury hour (PIH) 24 were recorded. The levels of hemoglobin, haematocrit, and blood lactic acid at admission, PIH 24 and 48 were recorded. (2) The creatine kinase isozyme-MB (CK-MB), total bilirubin, blood creatinine, oxygenation index, and blood platelet count at admission, at shock stage, and on post injury day (PID) 3 to 7 were collected. (3) The days of seriously or critically ill and deaths were recorded. Data were processed with chi-square test, group t test, Mann-Whitney U test, analysis of variance for repeated measurement, and Bonferroni correction. Results: (1) There were no statistically significant differences in fluid replacement volume within the first and second PIH 24, and urine volume within the second PIH 24 between patients in the 2 groups (t=0.351, 1.307, 1.110, P>0.05). The urine volume of patients in group E within the first PIH 24 was significantly less than that in group YM (t=5.628, P<0.05). There were no statistically significant differences in levels of hemoglobin (t=0.011, 1.075, 0.239), haematocrit (t=0, 0.033, 0.199), and blood lactic acid (t=0.017, 1.002, 0.739) at admission, PIH 24 and 48 between patients in the 2 groups (P>0.05). (2) There were no statistically significant differences in levels of CK-MB at admission and on PID 3 to 7 between patients in the 2 groups (t=0.069, 0.001, P>0.05). The level of CK-MB of patients in group E at shock stage was significantly higher than that in group YM (t=4.017, P<0.05). There were no statistically significant differences in levels of total bilirubin at admission and on PID 3 to 7 between patients in the 2 groups (t=0.227, 0.002, P>0.05). However, the level of total bilirubin of patients in group E at shock stage was significantly higher than that in group YM (t=6.485, P<0.05). The levels of blood creatinine of patients in group E at admission and shock stage were significantly higher than those in group YM (t=4.226, 12.299, P<0.05 or P<0.01), while there was no statistically significant difference between them on PID 3 to 7 (t=0.693, P>0.05). The oxygenation indexes of patients in group E at admission and shock stage and on PID 3 to 7 [(371±16), (263±16), and (228±18) mmHg (1 mmHg=0.133 kPa)] were lower than (420±13), (327±13), and (281±17) mmHg of patients in group YM, respectively (t=5.650, 9.782, 4.856, P<0.05 or P<0.01). There were no statistically significant differences in levels of blood platelet count at admission and shock stage between patients in the 2 groups (t=0.038, 0.588, P>0.05), while the level of blood platelet count of patients in group E on PID 3 to 7 was significantly lower than that in group YM (t=6.636, P<0.05). (3) The days of seriously or critically ill and death rate of patients in group E were respectively longer or higher than those in group YM (Z=-2.303, χ(2)=13.676, P<0.05 or P<0.01). Conclusions: In the case of the same tissue perfusion at shock stage, injuries in heart, liver, kidney, lung, and coagulation system in elderly patients with severe burns are more obvious than those in young and middle-aged patients, with more severe illness and higher mortality.

[In vitro study of the effect of human antigen R on lysosomal acidification during autophagy in mouse cardiomyocytes].

Objective: To investigate the effect of human antigen R on lysosomal acidification during autophagy in mouse cardiomyocytes cultured in vitro. Methods: The hearts of 20 C57BL/6 mice aged 1-2 days no matter male or female were isolated to culture primary cardiomyocytes which were used in the following experiments. (1) The cells were divided into 5 groups according to the random number table (the same grouping method below), i. e., normal control group and sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups. The cells in normal control group were routinely cultured for 54.0 h with Dulbecco's modified Eagle medium/nutrient mixture F12 (DMEM/F12) medium (the same regular culture condition below), and the cells in sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups were firstly regularly cultured for 53.5, 53.0, 51.0, 48.0 h and then cultured with replaced sugar-free serum-free medium for 0.5, 1.0, 3.0, and 6.0 h, respectively. The protein expressions of microtubule-associated protein 1 light chain 3 Ⅱ (LC3Ⅱ), autophagy-related protein 5, and adenosine triphosphatase V1 region E1 subunit (ATP6V1E1) were detected by Western blotting. (2) The cells were divided into normal control group and sugar-free serum-free 3.0 h group. The cells in corresponding groups were treated the same as those in experiment (1), and the cell lysosomal acidification level was observed and detected under a laser scanning confocal microscope. (3) Two batches of cells were grouped and treated the same as those in experiment (1). The protein expression of human antigen R in the whole protein of cells of one batch and its protein expression in the cytoplasm and nucleus protein of cells of the other batch were detected by Western blotting. (4) The cells were divided into normal control group, simple control small interfering RNA (siRNA) group, simple human antigen R-siRNA1 (HuR-siRNA1) group, simple HuR-siRNA2 group, sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, sugar-free serum-free+ HuR-siRNA1 group, and sugar-free serum-free+ HuR-siRNA2 group. After 48 hours of regular culture, the cells in simple control siRNA group and sugar-free serum-free+ control siRNA group were transfected with negative control siRNA for 6 h, the cells in simple HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA1 group were transfected with HuR-siRNA1 for 6 h, and the cells in simple HuR-siRNA2 group and sugar-free serum-free+ HuR-siRNA2 group were transfected with HuR-siRNA2 for 6 h. Hereafter, the cells in these 8 groups were continuously cultured for 48 h with regular conditon, and then the cells in normal control group and each simple siRNA-treated group were replaced with DMEM/F12 medium, the cells in the other groups were replaced with sugar-free serum-free medium, and they were cultured for 3 h. The protein expression of human antigen R in the whole protein of cells was detected by Western blotting. (5) Two batches of cells were divided into sugar-free serum-free+ control siRNA group and sugar-free serum-free+ HuR-siRNA1 group, and the cells in corresponding groups were treated the same as those in experiment (4). The distribution and expression of human antigen R in the cells of one batch were observed and detected by immunofluorescence method, and the lysosomal acidification level in the cells of the other batch was observed and detected under a laser scanning confocal microscope. (6) Three batches of cells were divided into sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, sugar-free serum-free+ HuR-siRNA1 group, and sugar-free serum-free+ HuR-siRNA2 group, and the cells in corresponding groups were treated the same as those in experiment (4). The protein expressions of cathepsin D in the whole protein of cells of one batch, human antigen R in the cytoplasm protein of cells of one batch, and ATP6V1E1 in the whole protein of cells of the other batch were detected by Western blotting. (7) The cells were divided into normal control group, sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, and sugar-free serum-free+ HuR-siRNA1 group, and the cells in corresponding groups were treated the same as those in experiment (4). The mRNA expression of ATP6V1E1 in cells was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The sample number of each experiment was 3. Data were processed with independent data t test, one-way analysis of variance, least significant difference t test, and Bonferroni correction. Results: (1) Compared with those of normal control group, the protein expressions of LC3Ⅱ and ATP6V1E1 in the whole protein of cells of sugar-free serum-free 1.0, 3.0, and 6.0 h groups were significantly increased (t=12.16, 4.05, 4.82, 11.64, 3.29, 8.37, P<0.05 or P<0.01). Compared with that of normal control group, the protein expression of autophagy-related protein 5 in the whole protein of cells of sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups was significantly increased (t=6.88, 10.56, 5.76, 9.91, P<0.05 or P<0.01). (2) Compared with 1.03±0.08 of normal control group, the lysosomal acidification level in the cells of sugar-free serum-free 3.0 group (2.92±0.30) was significantly increased (t=6.01, P<0.01). (3) There was no statistically significant difference in the overall comparison of protein expression of human antigen R in the whole protein of cells among the 5 groups (F=1.09, P>0.05). Compared with that of normal control group, the protein expression of human antigen R in the cytoplasm protein of cells was significantly increased in sugar-free serum-free 1.0, 3.0, and 6.0 h groups (t=43.05, 11.07, 5.39, P<0.05 or P<0.01), while the protein expression of human antigen R in the nucleus protein of cells was significantly decreased in sugar-free serum-free 3.0 and 6.0 h groups (t=11.18, 12.71, P<0.01). (4) Compared with that of simple control siRNA group, the protein expression of human antigen R in the whole protein of cells of simple HuR-siRNA1 group and simple HuR-siRNA2 group was significantly decreased (t=4.82, 4.44, P<0.05). Compared with that of sugar-free serum-free+ control siRNA group, the protein expression of human antigen R in the whole protein of cells of sugar-free serum-free+ HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA2 group was significantly decreased (t=4.39, 6.27, P<0.05). (5) Compared with those of sugar-free serum-free+ control siRNA group, the distribution of human antigen R in the cytoplasm of cells and its expression level were significantly decreased in sugar-free serum-free+ HuR-siRNA1 group (t=10.13, P<0.01). Compared with 1.00±0.06 of sugar-free serum-free+ control siRNA group, the lysosomal acidification level (0.73±0.06) in the cells of sugar-free serum-free+ HuR-siRNA1 group was significantly decreased (t=3.28, P<0.01). (6) Compared with those of sugar-free serum-free+ control siRNA group, the protein expressions of cathepsin D in the whole protein of cells, human antigen R in the cytoplasm protein of cells, and ATP6V1E1 in the whole protein of cells were significantly decreased in sugar-free serum-free+ HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA2 group (t=4.16, 3.99, 4.81, 5.07, 11.68, 12.97, P<0.05 or P<0.01). (7) Compared with that of normal control group, the mRNA expression of ATP6V1E1 in the cells of sugar-free serum-free 3.0 h group was significantly increased (t=5.51, P<0.05). Compared with that of sugar-free serum-free+ control siRNA group, the mRNA expression of ATP6V1E1 in the cells of sugar-free serum-free+ HuR-siRNA1 group was significantly decreased (t=5.97, P<0.05). Conclusions: After sugar-free serum-free treatment in vitro, the autophagy in mouse primary cardiomyocytes is activated, the lysosomal acidification is enhanced, and the expression of human antigen R in cytoplasm is increased. Human antigen R function is activated and involved in maintaining lysosomal acidification during autophagy in mouse cardiomyocytes.

[In vitro study of effects of transient receptor potential vanilloid 1 on autophagy in early hypoxic mouse cardiomyocytes and the mechanism].

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 (t(3 h)=4.891, 5.890, 4.928; t(6 h)=9.790, 6.750, 10.590; t(9 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.

[Role of hexokinase â ¡ in the changes of autophagic flow in cardiomyocytes of mice with ischemia-hypoxia in vitro].

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 (t(3 h)=16.15, 10.99, 5.30, t(6 h)=6.79, 10.42, 9.42, t(9 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.

Trends in atmospheric particles and their light extinction performance between 1980 and 2015 in Beijing, China.

This study explored the interdecadal variations and their horizontal and vertical light extinction performances of atmospheric particulate matter with aerodynamic diameters ≤2.5 µm (PM2.5), particulate matter with aerodynamic diameters ≤ 10 µm (PM10), and total suspended particulates (TSPs) in Beijing from 1980 to 2015, using data available from historical publications. Prominent declines of PM2.5, PM10, and TSPs were detected with long-term linear trends of -6.7, -4.3, and -1.9 µg m-3 yr-1, respectively. Generally, on the annual scale during the studied period, it was found that PM2.5 displayed negative correlation (R2 = 0.38, p < 0.01) with visibility and positive correlation (R2 = 0.41, p < 0.01) with aerosol optical depth (AOD). Comparably, PM10 exhibited robust negative correlation (R2 = 0.61, p < 0.01) with visibility and positive correlation (R2 = 0.82, p < 0.01) with AOD. The complicated interdecadal variations and light extinction performances of PM2.5 were found, suggesting the changes on particle composition and vertical distribution of PM2.5 in the atmosphere.

[Bleeding control of periodontal mechanical therapy for patients taking aspirin].

OBJECTIVE: To investigate the feasibility of periodontal mechanical therapy for chronic periodontitis and coronary heart disease patients with low dose of aspirin. METHODS: Sixty nine chronic periodontitis patients with coronary heart disease were randomly selected as the experimental group (medication group, group A), the control group (withdrawal group, group B) including 20 chronic periodontitis patients with coronary artery disease, stopping the drug for one week and another control group with 50 chronic periodontitis patients (group C). The three groups were examined with pocket probing, and received supragingival scaling, subgingival scaling, and root planning. Local bleeding after operation was observed. In 30 minutes after periodontal mechanical treatment, there was still a need to take some hemostatic measures (containing the oxidized cellulose putting in the periodontal pocket, gauze oppressing, and suturing). Nd:YAG laser was used to stop bleeding 60 minutes after operation. RESULTS: At baseline, there was no significant difference in the three groups, as to the plaque index(PLI), the probing depth (PD), and the attachment loss (AL). The bleeding index (BI)in group A was significantly higher than that in group C (P=0.024), higher than that in group B (P=0.088). The platelet maximum aggregation rate (Agg(max)) was detected in some subjects. The average Agg(max) value group A was 15.2%, which was much greater than that in group B (60.7%) and group C (62.5%). The three groups were all safe in the treatment of periodontal therapy. There were five cases of active bleeding in group A, one case in group B and one case in group C in 30 minutes after operation. In 60 minutes after operation, there was one case of bleeding actively in group A. Nd:YAG laser was used to stop bleeding successfully. CONCLUSION: The chronic periodontitis and coronary heart disease patients with long-term oral administration of low dose of aspirin can be safely treated with periodontal mechanical treatment, and the effect of local hemostasis is positive without stopping the drug.

[Risk prevention in patients on antithrombotic therapy for common oral invasive treatment].

The high incidence of cardiovascular diseases makes the dentists have more chance to treat patients who receive antithrombotic therapy. Limited by the profession, many dentists are unfamiliar with the systemic disease that the patients suffer from, especially struggle with whether or not to stop the antithrombotic therapy before the invasive diagnosis and treatment such as tooth extraction, dental implant placement and periodontal treatment. Stopping antithrombotic drugs may lead to thrombosis risk, while sustaining antithrombotic drug treatment may lead to bleeding risk. Through literature review and the experience of oral diagnosis and treatment of patients with cardiovascular diseases in our department for many years, the author aims to discuss preventive measures of bleeding and thrombosis risk of patients with oral antithrombotic therapy in oral invasive diagnosis.

Inverted repeats as genetic elements for promoting DNA inverted duplication: implications in gene amplification.

Inverted repeats are important genetic elements for genome instability. In the current study we have investigated the role of inverted repeats in a DNA rearrangement reaction using a linear DNA substrate. We show that linear DNA substrates with terminal inverted repeats can efficiently transform Escherichia coli. The transformation products contain circular inverted dimers in which the DNA sequences between terminal inverted repeats are duplicated. In contrast to the recombination/rearrangement product of circular DNA substrates, which is exclusively one particular form of the inverted dimer, the rearrangement products of the linear DNA substrate consist of two isomeric forms of the inverted dimer. Escherichia coli mutants defective in RecBCD exhibit much reduced transformation efficiency, suggesting a role for RecBCD in the protection rather than destruction of these linear DNA substrates. These results suggest a model in which inverted repeats near the ends of a double-strand break can be processed by a helicase/exonuclease to form hairpin caps. Processing of hairpin capped DNA intermediates can then yield inverted duplications. Linear DNA substrates containing terminal inverted repeats can also be converted into inverted dimers in COS cells, suggesting conservation of this type of genome instability from bacteria to mammalian cells.

Suppression of gene amplification and chromosomal DNA integration by the DNA mismatch repair system.

Mismatch repair (MMR)-deficient cells are shown to produce >15-fold more methotrexate-resistant colonies than MMR normal cells. The increased resistance to methotrexate is primarily due to gene amplification since all the resistant clones contain double-minute chromosomes and increased copy numbers of the DHFR gene. In addition, integration of linearized or retroviral DNAs into chromosomes is also significantly elevated in MMR-deficient cells. These results suggest that in addition to microsatellite instability and homeologous recombination, MMR is also involved in suppression of other genome instabilities such as gene amplification and chromosomal DNA integration.

Inversion/dimerization of plasmids mediated by inverted repeats.

In contrast with earlier studies on the lambda and Escherichia coli genomes, recombination between inverted repeats on plasmids is highly efficient and shown to be recA-independent. In addition, the recombination product is exclusively a head-to-head inverted dimer. Here, we show that this recombination/rearrangement event can occur on different plasmid replicons and is not specific to the particular sequence within the inverted repeats. Transcription readthrough into the inverted repeats has little effect on this event. Genetic analysis has also indicated that most known recombination enzymes are not involved in this process. Specifically, single or double mutants defective in Holliday junction resolution systems (RuvABC and/or RecG/RusA) do not abolish this recombination/rearrangement event. This result does not support the previous models (i.e. the reciprocal-strand-switching and the cruciform-dumbbell models) in which intermediates containing Holliday junctions are proposed. Further analysis has demonstrated that the recombination/rearrangement frequency is dramatically (over 1000-fold) reduced if mismatches (2.8 %) are present within the inverted repeats. Mutations in dam, mutH and mutL genes partially or completely restored the recombination/rearrangement frequency to the level exhibited by the perfect inverted repeats, suggesting the formation of heteroduplexes during recombination/rearrangement. Sequencing analysis of the recombination/rearrangement products have indicated that the majority of the products do not involve crossing-over. We discuss a possible mechanism in which blockage of the lagging strand polymerase by a hairpin triggers recombination/rearrangement mediated by inverted repeats.

A cruciform-dumbbell model for inverted dimer formation mediated by inverted repeats.

Small inverted repeats (small palindromes) on plasmids have been shown to mediate a recombinational rearrangement event in Escherichia coli leading to the formation of inverted dimers (giant palindromes). This recombinational rearrangement event is efficient and independent of RecA and RecBCD. In this report, we propose a cruciform-dumbbell model to explain the inverted dimer formation mediated by inverted repeats. In this model, the inverted repeats promote the formation of a DNA cruciform which is processed by an endonuclease into a linear DNA with two hairpin loops at its ends. Upon DNA replication, this linear dumbbell-like DNA is then converted to the inverted dimer. In support of this model, linear dumbbell DNA molecules with unidirectional origin of DNA replication (ColE1 ori ) have been constructed and shown to transform E.coli efficiently resulting in the formation of the inverted dimer. The ability of linear dumbbell DNA to transform E.coli suggests that the terminal loops may be important in bypassing the requirement of DNA supercoiling for initiation of replication of the ColE1 ori.

Specific stimulation of recA-independent plasmid recombination by a DNA sequence at a distance.

Recombination between directly repeated DNA sequences can occur via both recA-dependent and recA-independent mechanisms. They are differentially affected by the length of the repeat and the distance separating the repeats, respectively. Interestingly, a 623 base-pairs long DNA sequence of the plasmid pBR322 was found to stimulate specifically recA-independent recombination between tandem repeats. Analysis of this stimulating sequence has revealed the following features. (1). It is cis-acting. (2). No specific region of it appears to be essential for the effect. Moreover, a neutral sequence of comparable size was able to substitute for the sequence in influencing recombination. (3). The sequence affects recombination between tandem repeats within the tetA but not the bla gene of pBR322. (4). The sequence exerts its effect in a position-dependent manner. (5). It changes not only the frequency but also the products of recombination. Our results provide an example that recA-independent recombination can be influenced by DNA sequences at a distance.