Objective To observe the protective effects of natural antioxidant tea polyphenols(TP) on myocardial free radical metabolic disorder in mice induced by inhalation of hypobaric pure oxygen under 5500 m hypobaric condition. Method Fourty-two male Kunming mice were randomly divided into three groups(n=14 each):group A, normal control; group B, inhalation of pure oxygen(>96%) at simulated altitude of 5500 m in an animal altitude chamber;group C(TP protection group), same as group B but 100 mg/kg of TP was given orally before the exposure. The exposure time was 2 h/d,3 d/wk for a total of 8 wk, and distilled water was given to groups A and B before exposure. After experiment, the mice were decapitated on the next day and the heart was quickly removed. Malondialdehyde(MDA) concentration, superoxide dismutase(SOD) activity and nitric oxide(NO) content were measured. In addition, Cu,Zn-SOD and inducible NO synthase(iNOS) enzymatic contents in myocardial tissue were qualitatively examined by immunohistochemical assaying. Result Compared with the control, MDA concentration, SOD activity and Cu,Zn-SOD enzymatic content in group B were significantly increased(P<0.05).But in TP protection group, myocardial MDA formation was significantly decreased(P<0.01) and SOD activity and Cu,Zn-SOD expression restored to normal. On the contrary, myocardial NO generation and iNOS expression were significantly reduced after repeated inhalation of hypobaric oxygen at 5500 m.NO metabolism regained to normal after repeated administration of TP. Conclusion Natural antioxidant TP had protective effects on myocardial free radical metabolic disorder induced by inhalation of hypobaric pure oxygen under 5500 m hypobaric condition.

Objective To observe the effects of tea polyphenols (TP) on cardiac function and myocardial ultrastructure in rats after repeated +10 Gz stress. Method Twenty four male Wistar rats were randomly divided into three groups (n=8 each): group A (control), group B (+10 Gz), group C (+Gz with TP). Group B and C were repeatedly exposed to +10 Gz (each for 30 s, onset rate about 0.5 G/s, 3 times/d with +1 Gz 1 min intervals, 3 d/wk, 4 weeks in total), but group A was only submitted to +1 Gz. TP(200 mg.kg-1) was given orally to group C about 1h prior to the +Gz experiment, and distilled water was given to group A and B.Function of isolated rat working hearts and myocardial ultrastructure were observed. Result A significant decrease of left ventricular systolic pressure (LVSP) and injury of myocardial structure in rats were demonstrated after repeated +10 Gz stress. But TP could remarkably elevate the LVSP and improve myocardial ultrastructural injury in +10Gz stressed rats. Conclusion These results indicated that repeated high G exposure may produce cardiac structural and functional injuries in rats which might be partly related to free radical metabolism; and antioxidant TP had significant protective effects on the hearts of +Gz stressed rats.

Objective To observe the effects of repeated +10 Gz stress on cerebral lipid peroxidation,liver and renal function in rats and the prophylactic effects of antioxidant tea polyphenols(TP).Method Twenty-four male Wistar rats were randomly divided into three groups(n=8 each):group A(control),group B(+10 Gz),and group C(TP).Group B and C were exposed to repeated +10 Gz stress(each for 30s,onset rate about 0.5 G/s,3 times/d with +1 Gz 1 min intervals,3 d/wk,4 weeks in total),but group A was only submitted to +1 Gz.TP(200 mg/kg) was given orally in group C about 1 h prior to the +Gz experiment,while distilled water was given in group A and B.Lipid peroxidation in the brain,liver and renal functions and serum lipids were determined.Results As compared with the control,lipid peroxidation in rat cerebral homogenate,mitochondria and cytoplasm was significantly increased( P<0.05),and serum creatinine concentration was markedly elevated after repeated +10 Gz stress(P<0.01).But,TP had significant inhibitory effect on +10 Gz stress induced peroxidative injury in rat brain and reduced the serum creatinine level.There were no differences of serum triglyceride and total cholesterol concentrations and glutamic-pyruvic transaminase activity among the three groups.Conclusion These results indicated that repeated high +Gz stress could bring about peroxidative injury in brain and harmful effect on renal function,and natural antioxidant TP had signficant protective effects.

Autonomic nervous system activation can result in significant changes of atrial electrophysiology and facilitate induction of atrial fibrillation. By recording influence of different concentrations of acetylcholine (ACh) on atrial fibers (AF), we investigated the role of the increased vagal tone in electrical remodeling in atrial fibrillation. Parameters of action potentials and force contraction (Fc) in atrial fibers were recorded by using standard intracellular microelectrode technique and force transducer. It was found that: (1) ACh at 0.1 μmol/L had no significant influence on spontaneous action potentials (SAPs) and Fc (n=6, P>0.05); ACh at both 1.0 and 10.0 μmol/L shortened action potential duration (APD) and Fc of human AF from right atrium (n=6, P<0.05); there was no significant difference in shortening APD between 10.0 and 1.0 μmol/L of ACh; (2) ACh at 0.1 μmol/L had no significant desensitization (n=6, P>0.05), but ACh at 1.0 and 10.0 μmol/L had desensitization (n=6, P<0.05) to SAPs and Fc. The desensitization of ACh on APD in AF was concentration- and time-dependent. It was shown that APD was longer than the control along with extending time of continuous Tyrode's solution perfusion after desensitization. It is concluded that ACh changes the electrophysiological characteristics of human AF, indicating that increased vagal tone plays a role in the development of a vulnerable substrate for atrial electrical remodeling in atrial fibrillation.

Autonomic nervous system activation can result in significant changes of atrial electrophysiology and facilitate induction of atrial fibrillation.By recording influence of different concentrations of acetylcholine (ACh) on atrial fibers (AF),we investigated the role of the increased vagal tone in electrical remodeling in atrial fibrillation.Parameters of action potentials and force contraction (Fc) in atrial fibers were recorded by using standard intracellular microelectrode technique and force transducer.It was found that:(1) ACh at 0.1 μmol/L had no significant influence on spontaneous action potentials (SAPs) and Fc (n=6,P＞0.05); ACh at both 1.0 and 10.0 μmol/L shortened action potential duration (APD) and Fc of human AF from right atrium (n=6,P＜0.05); there was no significant difference in shortening APD between 10.0 and 1.0 μmol/L of ACh; (2) ACh at 0.1 μmol/L had no significant desensitization (n=6,P＞0.05),but ACh at 1.0 and 10.0 μmol/L had desensitization (n=6,P＜0.05) to SAPs and Fc.The desensitization of ACh on APD in AF was concentration- and time-dependent.It was shown that APD was longer than the control along with extending time of continuous Tyrode's solution perfusion after desensitization.It is concluded that ACh changes the electrophysiological characteristics of human AF,indicating that increased vagal tone plays a role in the development of a vulnerable substrate for atrial electrical remodeling in atrial fibrillation.

Objective To study the biological characteristics of platelet-derived growth factor A and human beta defensin 2 (hPDGF-A/hBD2) gene-modified rat bone marrow mesenchymal stem cells (BMSCs). Methods By using liposome transfection technique, recombinant adenovirus vector expressing hPDGF-A/hBD2 (Adv-hPDGF-A-IRES-hBD2) labeled with GFP was transfected into 293T cells for virus packaging and amplification. BMSCs were isolated, cultured and infected by adenovirus-containing supernatant. The exogenous gene-modified BMSCs were comprehensively studied on their biological features, in terms of morphology, cell growth curve, cell cycle, and adipogenic, osteogenic and myogenic differentiation ability. Results hPDGF-A-IRES-hBD2 gene-modified BMSCs did not show obvious changes in cell viability, proliferation, cell cycle distribution or cell differentiation. Conclusion BMSCs were not only good carriers for exogenous hPDGF-A and hBD2 genes but also seed cells for cell therapy even after hPDGF-A/hBD2 modification.

Objective:To evaluate the influencing factors of carotid-femoral pulse wave velocity (CF-PWV) and its value to predict outcomes in peritoneal dialysis (PD) patients.Methods:Eligible patients undergoing PD in Renji Hospital of Shanghai Jiao Tong University between August 2016 and July 2018 were recruited and prospectively followed up until death, PD cessation, or to the end of the study. CF-PWV was measured by an arterial pulse wave velocity meter to assess arterial stiffness (July 31, 2020). Overhydration was measured by bioimpedance spectroscopy. The patients were divided into CF-PWV≤10 m/s group and CF-PWV>10 m/s group according to the measured value of CF-PWV. The influencing factors of elevated CF-PWV were analyzed by multivariate logistic regression. Survival curves were generated using the Kaplan-Meier method and multivariate Cox proportional hazards models were used to analyze the difference for all-cause mortality and cardiovascular disease (CVD) mortality between the two groups.Results:A total of 224 PD patients were enrolled, including 133 males (59.4%). The age was (55.2±13.4) years old, and median PD vintage was 22.3(6.5, 59.3) months. Among them, 47(21.0%) patients were comorbid with diabetes, and 37(16.5%) patients had CVD history. The median CF-PWV was 9.6(8.4, 11.4) m/s for the cohort, and 105(46.9%) participants had CF-PWV over 10 m/s. Compared with CF-PWV≤10 m/s group, CF-PWV>10 m/s group patients had older age, increased percentage of diabetes and CVD (all P<0.05). Multivariate logistic analysis showed that increased age ( OR=1.070, 95% CI 1.043-1.099, P<0.001), diabetes ( OR=3.693, 95% CI 1.646-8.287, P=0.002) and higher overhydration ( OR=1.238, 95% CI 1.034-1.483, P=0.020) were independent influencing factors for elevated CF-PWV in PD patients. After followed up for 37.4(25.6, 41.7) months, 24 patients died, including 19 cases of CVD-related deaths. Kaplan-Meier survival analysis showed that all-cause mortality and CVD mortality were significantly higher in the CF-PWV>10 m/s group than those in CF-PWV≤10 m/s group (Log-rank χ2=6.423, P=0.011; Log-rank χ2=6.243, P=0.012, respectively). Multivariate Cox proportional hazards models showed that increased age was an independent influencing factor for both all-cause mortality and CVD mortality ( HR=1.057, 95% CI 1.010-1.107, P=0.018; HR=1.062, 95% CI 1.009-1.118, P=0.022). Conclusions:Increased arterial stiffness is relatively common in PD patients. Higher CF-PWV in PD patients is associated with increased age, diabetes and higher overhydration, and it is probably a valuable predictor of outcome in PD patients.

OBJECTIVEThe survey will reveal current status of subclinical vitamin A deficiency (SVAD) and explore its affecting factors in children of China.

METHODSTotally 8 669 children aged under 6 years were randomly selected from 14 provinces for clinical examination, health and dietary questionnaire and serum level of vitamin A measurement with fluorescence method. The cut-off value for SVAD was defined as

RESULTSPrevalence of SVAD was 11.7% and that of suspected SVAD 39.2% in all subjects, which decreased with the increase of gross domestic product, average annual family income, mother's schooling and children's age. Prevalence of SVAD and suspected SVAD higher in rural areas (15.0%) than in urban areas (5.2%), and higher in children with a minority mother (22.6%) than in those with a Han nationality mother (8.7%). Prevalence of SVAD and suspected SVAD was higher in children whose blood samples were collected within one week in-taking vitamin A-rich food (12.6%-22.6%) than those in-taking vitamin A daily (4.1%-10.0%), and higher in children suffering from respiratory infection, fever and diarrhea two weeks before their blood collection (15.2%-20.3%) than in those without those diseases (10.1%-11.1%). Logistic regression analysis showed that poor family economic status, living in rural areas, children with a minority mother, younger age, no-dairy milk products intake, and respiratory infection and fever all were risk factors for SVAD.

CONCLUSIONSMore than half of children under six years old in China (50.9%) had vitamin A nutrition problem. Varied factors played roles to different extent in SVAD in children.

Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Male ; Prevalence ; Vitamin A ; blood ; Vitamin A Deficiency ; epidemiology ; etiology

OBJECTIVETo screen the molecular markers of DNA methylation with potential diagnostic value, and to explore their methylation features in Chinese colorectal neoplasma in order to find out ones with higher diagnostic value.

METHODSTissue samples of colorectal cancer and normal adjacent mucosa(>10 cm distance to tumors) from 10 colorectal cancer patients undergoing operation, and tissue samples of colorectal adenoma from 10 patients undergoing endoscopic resection in our center from June to August 2013 were collected respectively. Methylation status of 8 genes, such as SNCA, MAL, INA, SPG20, FBN1, CNRIP1, TFPI2, OSMR, was detected by BSP and qMSP to screen genes with potential diagnostic valua. ROC curve was drawn to analyze its diagnostic value.

RESULTSBSP measurement showed that the rate of DNA methylation of SNCA, SPG20 and FBN1 was 100% in colorectal cancer and adenoma, while no methylation was found in normal adjacent mucosa. The other 5 genes expressed in different extent in cancer, adenoma and normal adjacent mucosa. Among 10 cancer tissues and normal adjacent mucosa detected by qMSP method, positive SNCA methylation was found in 5 cases and 1 case respectively; positive SPG20 in 8 cases and 1 case respectively; positive FBN1 in 7 cases and 0 cases respectively, whose differences were significant (P=0.070, P=0.003 and P=0.007). The area under curve(AUC) of SNCA, SPG20, and FBN1 methylation for diagnosing colorectal cancer was 0.890, 0.730 and 0.880 respectively.

CONCLUSIONSNCA, SPG20 and FBN1 are potential genes with screening value for colorectal neoplasma.

Objective:To evaluate the differential expression of blood routine in different types of infection and the diagnostic value of C-reactive protein (CRP), procalcitonin (PT), ferritin (SF) and lactate dehydrogenase (LDH) in bacterial and mycoplasma pneumonia and their early warning value in severe cases.Method:A total of 627 patients, including 176 cases of bacterial pneumonia, 275 cases of mycoplasma pneumonia, 176 cases of viral infection and 180 cases of normal control were collected from May 2018 to December 2019 in children′s Hospital Affiliated to Capital Institute of Pediatrics. The mycoplasma pneumonia group was divided into mild group (151 cases) and severe group (124 cases) according to the results of lavage fluid RNA-examination. All patients received completed blood routine test at the first day of admission, patients in bacteria group and Mycoplasma group received the examination of four inflammatory indicators. The Kruskal-Wallis test was used to analyze the differences in blood routine results between different infection groups, and the differences of inflammatory indexes between bacterial group and Mycoplasma mild and severe group. The receiver operating characteristic (ROC)-curve method was used to analyze the predictive value of inflammatory indexes between different infection groups.Results:There were significant differences in leukocyte count, neutrophil, lymphocyte and monocyte percentage between bacterial pneumonia, mycoplasma pneumonia, viral infection and normal control group ( P<0.05). The differences of four inflammatory indexes in bacterial group, mild Mycoplasma group and severe group were statistically significant ( P<0.05). The rest of the index (CRP, PCT, LDH, SF and white blood cell count) were P<0.05 (CRP: area under curve [AUC] 0.799; PCT: AUC 0.579; LDH: AUC 0.651; SF: AUC 0.854), in mild and severe mycoplasma group, except WBC, by ROC-curves analysis. The AUC value of the area under the curve of CRP and SF is high, and the sensitivity and specificity at the diagnostic critical point are high, which has great diagnostic value (CRP: diagnostic critical point 12.55 mg/L, sensitivity 0.719, specificity 0.755; SF: diagnostic critical point 176.02 μg/L, sensitivity 0.765, specificity 0.960). ROC curve results also showed that of PCT, White blood cell and neutrophil percentage had the diagnostic value in bacterial infection and mycoplasma infection, P<0.05 (PCT: AUC 0.658; leukocyte: AUC 0.804; neutrophil: AUC 0.630). Leukocyte count is the best differential index (diagnostic critical point 9.585×10 9/L, sensitivity 0.778, specificity 0.698), PCT has higher sensitivity at the diagnostic critical point of 0.55 μg/L, but the specificity is slightly lower (diagnostic critical point of 0.55 μg/L, sensitivity 0.862, specificity 0.366). Conclusions:PCT and leukocyte count can be used as the preferred inflammatory indexes to distinguish bacterial and mycoplasma infection. CRP, LDH, PCT and SF can be used as early warning indexes to evaluate severe mycoplasma infection.