AIM:To study the function of pancreatic ? cells in the R6/2 transgenic mouse of Huntington's disease(HD),and to elucidate the pathogenetic mechanisms underlying diabetes mellitus in transgenic mice of HD. METHODS:By using the R6/2 transgenic mouse model of HD,fasting blood glucose and fasting insulin concentration in plasma of normal and HD mice were detected. Further,HE staining and immunofluorescence technique were used for morphometric analysis of islets in normal and HD mice. RESULTS:In contrast to normal mouse,R6/2 HD mouse showed hyperglycemia and hypoinsulinemia in fasting state. Pancreatic islets morphology showed that islets atrophied and cell number decreased in HD mouse. Poor functional index was observed in these mice,but insulin resistance index was normal. CONCLUSION:Impaired function of pancreatic cells may be the key factor contributing to the pathogenesis of diabetes in the R6/2 transgenic mouse model of HD.

Objective To study the effect of heat shock protein 40(HSP40) and heat shock protein 70(HSP70) on the aggregate formation of mutant huntingtin (htt) and its toxicity in N2a cells. Methods The effect of the over-expression of HSP40 and HSP70 alone or co-over-expression of them on aggregate formation of transfected mutant htt (containing 150 glutamine repeats, 150Q) in N2a cells was detected by fluorescence microcopy and Western blotting. Cell viabilities were detected by MTT assay. Reactive oxygen species (ROS) production was detected by colorimetric method. Results The over-expression of HSP40 and HSP70 alone, especially the co-over-expression of them, dramatically decreases the formation of 150Q htt aggregates in N2a cells. The numbers of aggregates in each group are as follows ( n = 1 000): about 50% in the group of 150Q htt-expressing alone, about 12% in the group of over-expression of HSP40, about 15% in the group of over-expression of HSP70, about 5% in the group of co-over-expression of HSP40 and HSP70. The result of MTT assay shows that the over-expression of HSP40 and HSP70 alone, especially the co-over-expression of them, dramatically increases cell viabilities ( P<0.01, n =3) and reduces the production of ROS ( P<0.01, n =3). Conclusion HSP40 and HSP70 can increase cell viabilities of 150Q N2a cells via inhibiting the aggregates formation of mutant huntingtin and reducing oxidative stress.

Objective To explore the clinical characteristics and risk factors of catheterrelated infection in continuous renal replacement therapy (CRRT) patients.Methods The demographic and clinical data of CRRT patients who inserted with double-lumen non-cuffed dialysis catheter at the First Affiliated Hospital of Sun Yat-sen University from January 1,2016 to December 31,2016 were collected.According to the presence or absence of catheter-related infections,they were divided into infected group and uninfected group.Statistics and analysis of the incidence and pathogenic characteristics of catheter-related infections;Comparison of clinical features of infected and uninfected groups;A multivariate Cox proportional hazard model was used to analyze risk factors for catheter-related infections.Results A total of 364 patients with CRRT (437 cases of central venous catheterization) were enrolled in the study.Catheter-related bloodstream infection (CRBSI) and catheterrelated colonization (CRCOL) rates were 3.565 and 2.228 events per 1000 catheter-days.These catheters were associated with higher proportion of inserted in ICU (P=0.007),immunosuppression (P=0.002),receive catecholamine inotropes therapy (P=0.001) and shock (P=0.030).The infection catheters also had shorter indwelling time (P=0.032) and lower level of blood hemoglobin (P=0.017),serum creatinine (P=0.004),blood brain natriuretic peptide (P=0.005) pericatheter use.The most common pathogens were Gram-negative bacteria,especially Acinetobacter baumannii,which caused 37.5％ CRBSI and 20.0％ CRCOL.Multivariate Cox regression model showed female (P=0.029,HR=2.151),diabetes (P=0.016,HR=2.807),receive catecholamine inotropes therapy (P=0.012,HR=2.655),immunosuppression (P=0.037,HR=2.203) were independent risk factors associated with catheterrelated infection.Conclusions The incidence of CRBSI and CRCOL is 3.565 and 2.228 events per 1000 catheter-days CRRT patients in our hospital.The most common pathogen of catherter-related infection is Gram-negative bacteria.Female,diabetes,received catecholamine inotropic drugs,and immunosuppression were independent risk factors associated with catheter-related infection.

Objective To explore the differential expression of the key microfilament cytoskeleton-binding proteins in immature dendritic cells(imDCs)during antigen phagocytosis.Methods Monocytes(MOs)were isolated from peripheral blood of healthy individuals and cultured with recombinant human granulocyte-macrophage colony stimulating factor(rhGM-CSF)and recombinant human interleukin-4(rhIL-4)for 6 days to obtain imDCs.ImDCs were co-cultured with low molecular weight(40 kDa)and high molecular weight(150 kDa)dextrans for 1,3 and 6 hours,respectively.Flow cytometry was used to detect the percentage of imDCs phagocytosing dextran and the expression of immunophenotype molecules.The localization of filamentous actin(F-actin),PFN1,WASP,and α-actinin in cells were observed by immunofluorescence imaging.The differential expression of MCBPs at the mRNA and protein levels were respectively detected by q-PCR and Western blotting.Finally,the MCBPs with the highest component coefficients were identified based on the stepwise regression and principal component analysis method in systems biology algorithms.Results During the process of antigen phagocytosis,imDCs phagocytized low molecular weight antigens at a faster rate,with a phagocytic duration of approximately three hours.Their cell phenotypes and morphology gradually differentiated into mDCs,and F-actin remodeling was occurred significantly.The expression of MCBPs such as PFN1,CDM,WASP,CAPZB,Filamin A,α-actinin were downregulated,while the expression of WAVE1,Arp2/3 complex,and Fascin were upregulated.The mRNA expression of signaling protein Rac1 was upregulated,while the mRNA expressions of CDC42 and RhoA were downregulated.The immunofluorescence results showed that PFN1,WASP,and α-actinin were transposed during the antigen phagocytosis process of imDCs.The results of stepwise regression and principal component analysis showed that PFN1 had the highest component coefficient.Conclusions PFN1 may be a key MCBPs involved in the process of antigen phagocytosis of imDCs,which is of great significance for further understanding the relationship between changes in the cytoskeleton structure of imDCs and their immunological functions.