Objective To study the relationship between environment selenium distribution characteristic and Kaschin-Beck disease (KBD) in the Yarlung Zangbo River banks and to provide some measures for prevention and control of KBD in the north side of the river bank.Methods Considering the geography and KBD distribution,we made a survey in Xietongmen (KBD area),Lazi and Sajia (non-KBD area) counties in 2013 and 2015.Water,soil,herbage,grain food and children hair samples were collected.Selenium of the samples was measured by hydride generation-atomic fluorescence spectrometry.Results A total of 246 samples of natural soil,cultivated soil,drinking water,food and forage,and 103 samples of children hair were collected.The selenium in natural soil,cultivated soil,herbage,barley,tsampa,self-produced wheat in non-KBD area in the south side of Yarlung Zangbo River bank were significantly higher than those in KBD areas in the north side [mean (μg/kg):288.62 vs 134.90,228.26 vs 160.28,41.85 vs 5.10,13.99 vs 4.02,12.64 vs 8.07,27.44 vs 13.56,U =7,23,0,19,62,0,P ＜ 0.05].Hair selenium in school children in KBD area in the north side was higher than that previously reported,but still significantly lower than that in non-KBD areas in the south side of the river bank [mg/kg:0.221 vs 0.306,U =650,P ＜ 0.01],and about 65.45％ (36/55)of school children in KBD area were at a risk of selenium deficiency in the north of the Yarlung Zangbo River bank.Conclusions The selenium contem in the food chain of soilplants-animals (human being) is significantly lower in KBD area in the north side of Yarlung Zangbo River bank than that in non-KBD areas in the south side.It's still a key factor for the occurrence and prevalence of KBD that low selenium in environment in KBD areas in the north side.

Objective:To observe the application effect of formative evaluation of embedded standard patient (SP) on internal medicine practice teaching.Methods:In this study, 110 students from our school in Batch 2014 who were interned in the internal medicine of the same affiliated hospital were selected as the research objects, and they were randomized into the experimental group and the control group, with 55 students in each group. The control group was trained with traditional clinical practice teaching methods. The experimental group used SP combined mini-clinical evaluation exercise (Mini-CEX) to participate in the evaluation during the clinical practice teaching of internal medicine. After the internal medical practice, the two groups of students were evaluated by Mini-CEX, and the teaching effect of both groups was evaluated through questionnaires.Results:There was no significant difference in the degree of difficulty in the examinations ( P>0.05), but the test scores of the experimental group were significantly higher than those of the control group. The results of Mini-CEX used in inquiry skills, physical examination, humanistic care, and organizational effectiveness were significantly higher in the experimental group than in the control group. The experimental group was highly satisfied with the formative evaluation of SP participation in improving the effect of internal medicine practice, with statistical significance ( P<0.05). Conclusion:The formative evaluation with SP participation in this study can improve the clinical practice teaching effect of medical students to a certain extent.

Objective To investigate the role of STAT3 transcription factor in IL-6 inducing epithelial mesenchymal transition (EMT) of human peritoneal mesothelial cells (HPMCs).Methods HPMCs were cultured in vitro and grouped.(1) According to the stimulation time with 50 μg/L IL-6,HPMCs were divided into 24,48,72 h groups.(2) HPMCs were grouped 50,100 μg/L according to IL-6 concentration.(3) HPMCs were respectively divided into control group,IL-6 group,empty vector group,empty vector+IL-6 group,virus infecting group and virus infecting+IL-6 group,as lenti-virus vector mediating RNA interference targeting STAT3 was applied.The mRNA expressions of E-cadherin,α-smooth muscle actin (α-SMA) and vascular endothelial growth factor (VEGF) were detected by real time PCR;their protein expressions and the phosphorylation of JAK2 and STAT3 were detected by Western blotting;the expressions and distribution of E-cadherin and α-SMA were observed by immunofluorescence.Results Compared with those in control group,the expression of E-cadherin decreased remarkably (P ＜ 0.05),while the expressions of VEGF and α-SMA and the ratio of phosphorylated (p)-JAK2/JAK2 and p-STAT3/STAT3 increased significantly in IL-6 concentration groups and stimulation time groups (all P ＜ 0.05),which had been dose and time dependent.Compared with empty vector+IL-6 group,virus infecting+IL-6 group had decreased expressions of VEGF and α-SMA,while increased expressions of E-cadherin (all P ＜ 0.05).Conclusions IL-6 can promote VEGF and α-SMA gene expression and prevent E-cadherin gene expression by STAT3,which involves in EMT of peritoneum fibrosis.While STAT3 gene is knocked-down,EMT is inhibited in HPMCs.

Objective To investigate the association of red cell distribution width (RDW) with all-cause and cardiovascular disease (CVD)-related mortality in patients undergoing continuous ambulatory peritoneal dialysis (CAPD).Methods A retrospective analysis was performed on 207 patients who initiated CAPD for more than 3 months between July 2005 and March 2016 in the First Hospital Affiliated to Zhengzhou University.Baseline data on demographic,clinical and biochemical variables as well as comorbidities were obtained;medications and clinic outcomes were recorded.According to receiver operator characteristic curve (ROC) analysis,patients were divided into high RDW (RDW ＞ 15.1％) and low RDW (RDW≤ 15.1％) groups.The data of two groups were compared and Spearman's correlation analysis was used to explore the association of RDW with clinical and biochemical parameters.Survival curves were calculated using Kaplan-Meier method.Cox regression model was employed to analyze risk factors of all-cause and CVD-related mortality.Results In this study,207 CAPD patients were enrolled.The overall median survival time was 80 months.And the median survival time of high RDW group (68 patients) and low RDW group (139 patients) were 59 months and 96 months,respectively.There were statistical differences in diastole pressure,hemoglobin,hematocrit,serum albumin,intact parathyroid hormone (iPTH),eGFR,cholesterol,lipoprotein a,4-hour dialysate-to-plasma ratio for creatinine (4hD/Pcr),total Ccr (P ＜ 0.05,respectively);the two groups also varied in the proportion of chronic obstructive pulmonary disease,cardiovascular disease and hyperlipidemia,as well as in the use of iron supplements,angiotensin-converting enzyme (ACE) inhibitors or angiotensin Ⅱ receptor blockers (ARB),and beta-receptor blockers (P＜0.05,respectively).Cardiovascular event was a leading cause of mortality.Kaplan-Meier survival curves showed that the high RDW group had higher all-cause and CVD-related mortality compared with the low RDW group (P ＜ 0.01).The 1-year,3-year,and 5-year patient survivals of the high RDW and low RDW group were 87.97％ vs 97.01％,58.02％ vs 81.53％,and 41.62％ vs 67.96％,respectively,demonstrating significant differences (P=0.001).Multivariate Cox regression analysis showed that high RDW was independent risk factor for all-cause mortality (HR=1.212,95％CI:1.007-1.458,P=0.042) and CVD-related mortality (HR=1.697,95％ CI:1.030-2.795,P=0.038).Conclusion RDW is associated with mortality risks in CAPD patients and can be stratified as a valuable indicator for the risk of death.

Objective To investigate whether the JAK2/STAT3 signaling pathway is involved in the epithelial-mesenchymal transition (EMT) of peritoneal mesothelial cells in uremic peritoneal dialysis (PD) rats.Methods A total of 48 male Sprague-Dawley (SD) rats were randomly separated into six groups:normal control group (NC group,n=8),sham group (n=8),uremic group (n=8),PD group (n=8),S3I-201 control group (n=8) and S3I-201 group (n=8).Uremic model generated by 5/6 nephrectomy surgery in rats was established.The rats of PD group,S3I-201 control group and S3I-201 group received daily infusion of 4.25％ glucose-based peritoneal dialysate fluid (3 ml/100 g) from PD catheters for 28 days.Rats of S3I-201 group were injected with STAT3 inhibitor S3I-201 (2.5 mg/kg) solution from the catheters every other day;the same dose of the solvent of S3I-201 was simultaneously given to S3I-201 control group rats.After PD for 28 days,peritoneal function,pathologic changes,and microvessel density (MVD) were evaluated.Creatinine,urea nitrogen and interleukin-6 (IL-6) concentration in blood and dialysate,and protein and mRNA levels of phospho-JAK2 (p-JAK2),phospho-STAT3 (p-STAT3),E-cadherin,alpha-smooth muscle actin (α-SMA) and vascular endothelial growth factor (VEGF) in peritoneum were determined.Results Uremia and peritoneal dialysate could aggravate the peritoneal function and elevate peritoneal thickness and MVD.They could also increased the concentration of IL-6 in blood and dialysate and the expression levels of α-SMA,VEGF,p-JAK2 and p-STAT3 in peritoneum,while lowering E-cadherin expression in peritoneum.These manifestations were even more remarkable in PD group compared to those in uremic group.There was no statistical difference between the S3I-201 control group and the PD group as regards all the index (all P ＞ 0.05).Compared with the S3I-201 control group,the rats treated with S3I-201 showed better peritoneal function.S3I-201 could reduce peritoneal thickness (P＜0.05),MVD (P＜0.05),the concentration of IL-6 in blood and dialysate,the mRNA and protein expression of α-SMA,VEGF,p-JAK2 and p-STAT3 (all P ＜ 0.05),while enhance the mRNA and protein expression of E-cadherin (all P ＜ 0.05).Conclusions After STAT3 is inhibited,the peritoneal thickness,MVD and IL-6 concentration in PD rats are decreased,and EMT is also inhibited,while peritoneal function is improved.The JAK2/STAT3 signaling pathway may thus be involved in the process of EMT of peritoneum in uremic peritoneal dialysis rats by regulating the expression of IL-6.