[Effect of downregulation of phosphatase and tensin homolog gene expression on p130crk- related substrate protein and paxillin signal transduction in activated hepatic stellate cells in vitro]

Objective: To investigate the role of adenovirus-mediated short hairpin RNA (shRNA) in down-regulating the expression of phosphatase and tensin homologue deleted on chromosome ten (PTEN) on p130Crk-related substrates(p130Cas) and paxillin signal transduction to activate hepatic stellate cell (HSC) in vitro. Methods: The rat hepatic stellate cell line, HSC-T6 was cultured and activated in vitro. The adenovirus was used as a vector to transiently transfect shRNA targeting PTEN to activate HSC in vitro, and then PTEN low expression model of activated HSC in vitro was established. Western blot and real-time fluorescence quantitative PCR were used to detect the protein and mRNA expression of PTEN, p130cas and paxillin in activated HSC. The experiment was divided into control group (HSC were transfected with DMEM medium instead of adenovirus), Ad-GFP group (HSC were infected with empty the adenovirus expressing green fluorescent protein (GFP) alone), and Ad-shRNA/PTEN group (HSC were infected with the recombinant adenovirus containing both shRNA targeting PTEN and GFP gene). One-way analysis of variance was used for comparison of multiple groups, and LSD test was used for inter-group comparison. Results: shRNA targeting PTEN was successfully transfected and significantly down-regulated the PTEN protein and mRNA expression of HSC in vitro (P < 0.05), and the PTEN low expression model of HSC in vitro was successfully constructed. Compared with the expression of p130cas mRNA in the three groups of HSC, the expression fold of p130cas mRNA in the Ad-GFP group and the Ad-shRNA / PTEN group was 1.01 times and 1.52 times, respectively. The expression of p130cas mRNA in HSC of the Ad-shRNA / PTEN group was significantly higher than control group and Ad-GFP group (P < 0.05), but there was no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). The expression of p130cas protein in the three groups was higher than that in the control group (0.74 ± 0.07) and the Ad-GFP group (0.72 ± 0.02); P < 0.05, but there was no statistically significant difference between the Ad-GFP group and the control group (P > 0.05). The expression of paxillin mRNA in the three groups of HSCs was compared with the expression of paxillin mRNA in the control group of HSC being 1, the expression folds of paxillin mRNA in the Ad-GFP group and Ad-shRNA / PTEN group were 0.97 times and 1.58 times, respectively. The expression of paxillin mRNA in the Ad-shRNA / PTEN group was higher than that in the control group and the Ad-GFP group (P < 0.05), and there was no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). The expression of paxillin protein in the three groups of HSCs was higher in the Ad-shRNA / PTEN group (0.91 ± 0.05) than control group (0.46 ± 0.03) and Ad-GFP group (0.50 ± 0.04), P < 0.05, and there was no statistically significant difference between the Ad-GFP group and the control group (P > 0.05). Conclusion: Down-regulation of PTEN expression can significantly boost p130cas and signal transduction activity of paxillin protein in activated HSC in vitro.

[A prospective cohort study on the relationship between maternal prenatal depressive symptoms and children's behavioral problems at 2 years old]

Objective: To explore the associations between maternal and prenatal depressive symptoms and children's behavioral problems at 2 years old. Methods: In the present study, a total of 491 mother-child pairs were selected from the Shanghai-Minhang Birth Cohort Study (S-MBCS) which was conducted in Maternal and Child Health Hospital of Minhang District in Shanghai between April and December, 2012. Data from the Center for Epidemiologic Studies on Depression was gathered to assess the maternal depressive symptoms in the second and third trimester of pregnancy, as well as at 6 months and 12 months postpartum. Neurodevelopment at 2 years was assessed, using the Child Behavior Checklist. We used generalized linear models with a log-link function and a Binomial distribution to estimate the risk ratios (RRs) and 95%CIs, on children's behavioral problems at 2 years of age. Sensitivity analyses were performed among participants without postpartum depressive symptoms. Results: After adjustment on factors as maternal age, gestation week, average monthly income per person, parental education and children's gender etc., maternal depression in second trimester of pregnancy was found associated with higher risk of both developing emotional (RR=2.61, 95%CI: 1.36-4.99) and internalizing problems (RR=1.94, 95%CI: 1.22-3.08). However, maternal depression in third trimester was found to be associated with higher risks of developing emotional (RR=6.46, 95%CI: 3.09-13.53), withdrawn (RR=2.42, 95%CI: 1.16-5.02), aggressive (RR=2.93, 95%CI: 1.45-5.94), internalizing (RR=1.79, 95%CI: 1.01-3.16) or externalizing problems (RR=2.56, 95%CI:1.49-4.42). In sensitivity analysis, antenatal maternal depression was found positively associated with children's emotional, internalizing and externalizing problems and the differences all statistically significant. Conclusions: Maternal depression during pregnancy might increase the risks of children's behavioral problems. In order to decrease the incidence of children's behavioral problems and promoting both maternal and child health status, monitoring program regarding maternal mental health care should be strengthened.

[Effects of wild-type PTEN overexpression and its mutation on F-actin in activated hepatic stellate cells]

Objective: To investigate the effect of overexpression of wild-type phosphatase and tensin homolog (PTEN) deleted on chromosome 10 and its mutant G129E (exhibiting the activity of protein phosphatase and losing the activity of lipid phosphatase) on F-actin in activated hepatic stellate cells (HSCs) cultured in vitro. Methods: The activated hepatic stellate cell-T6 (HSC-T6) cells were cultured in vitro, and activated HSCs were transfected with adenovirus that carried wild-type PTEN gene and G129E gene using transient transfection. The HSCs were divided into the following groups: control group, which was transfected with DMEM medium instead of virus solution; Ad-GFP group, which was transfected with the empty adenovirus vector with the expression of green fluorescent protein (GFP); Ad-PTEN group, which was transfected with the recombinant adenovirus with wild-type PTEN gene and GFP expression; Ad-G129E group, which was transfected with the recombinant adenovirus with G129E gene and GFP expression. Western blot and quantitative real-time PCR were used to measure the protein and mRNA expression of PTEN in activated HSCs; under a laser scanning confocal microscope (LSCM), phalloidine labeled with the fluorescein tetramethylrhodamine isothiocyanate (TRITC) was used to observe the morphology of HSCs, distribution and fluorescence intensity of F-actin, and changes in pseudopodia and stress fibers, and a calcium fluorescence probe (Rhod-2/AM) was used to measure the changes in Ca(2+) concentration in HSCs. A one-way analysis of variance was used for comparison between multiple groups, and the least significant difference test was used for comparison between two groups. Results: Wild-type PTEN and G129E genes were highly expressed in activated HSCs. In the control group and the Ad-GFP group, HSCs had a starlike or polygonal shape, F-actin was reconfigured and formed a large number of stress fibers which stretched across the whole cell, and layered pseudopodia were seen around the cell. In the Ad-PTEN group and the Ad-G129E group, the HSCs had a fusiform shape, F-actin was mainly seen around the cell, a small number of stress fibers were seen inside the cell, and layered pseudopodia around the cell disappeared. The Ad-PTEN group and the Ad-G129E group had significant reductions in the fluorescence intensity of F-actin compared with the control group and the Ad-GFP group (357.67±13.39/377.25±14.55 vs 961.87±27.33/954.68±20.71, F = 1783.486, P < 0.05), while there were no significant differences between the Ad-PTEN group and the Ad-G129E group, as well as between the control group and the Ad-GFP group (P > 0.05). The Ad-PTEN group and the Ad-G129E group had significant reductions in the relative concentration of Ca(2+) compared with the control group and the Ad-GFP group (251.60±90.88/352.18±146.01 vs 1953.95±132.99/1937.57±115.17, F = 834.988, P < 0.05), while there were no significant differences between the Ad-PTEN group and the Ad-G129E group, as well as between the control group and the Ad-GFP group (P > 0.05). Conclusion: The overexpressed wild-type PTEN and its mutant G129E can significantly inhibit the formation and reconfiguration of cytoskeletal protein F-actin and reduce the concentration of Ca2+ in activated HSCs in vitro. In addition, there are no significant differences in the above effects between wild-type PTEN and G129E.

Molecular epidemiological characteristics of Streptococcus pyogenes strains involved in an outbreak of scarlet fever in China, 2011

OBJECTIVE

To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011.

METHODS

Seventy-four Streptococcal pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis (PFGE), superantigen (SAg) genes and antimicrobial susceptibility profiling were analyzed for these isolates.

RESULTS

A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12 (79.7%) and emm1 (14.9%) accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emm1 isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously.

CONCLUSION

Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China.

Optimization of complex conditions by response surface methodology for APAM-oil/water emulsion removal from aqua solutions using nano-sized TiO2/Al2O3 PVDF ultrafiltration membrane

This paper studies the cumulative effect of various parameters, namely anionic polyacrylamide (APAM) concentration, oil concentration, pH, trans-membrane pressure (TMP), and total dissolved solid (TDS), and obtains optimal parameters for the minimum relative flux (J/J(0)) declining in aqueous solutions with response surface methodology (RSM). In order to analyze the mutual interaction and optimal values of parameters affecting ultrafiltration, a central composite rotatable design (CCRD), one method of RSM, was employed. The analysis of variance (ANOVA) of the cubic polynomial model demonstrated that this model was highly significant and reliable. The results show that the effect of APAM and oil on J/J(0) has an inverse trend with pH value increasing. Moreover, the mutual interaction of initial APAM (oil) concentration (C(APAM(oil))) and pH (TMP) were negligible, while the mutual interaction of C(APAM) and C(oil) has an obvious effect, i.e. the effect of initial feed C(APAM) became more important at higher values of initial feed C(oil), and the J/J(0) was only about 4%. The favorable operate conditions in this ultrafiltration process were at low C(APAM), C(oil), pH, and TMP, which agreed with the conclusions of many authors, while considering water production, C(APAM) and C(oil) < 50 mg/L, pH < 4, and TMP < 0.075 MPa could be accepted.

Isotherm and kinetic behavior of adsorption of anion polyacrylamide (APAM) from aqueous solution using two kinds of PVDF UF membranes

To determine the isotherm parameters and kinetic parameters of adsorption of anion polyacrylamide (APAM) from aqueous solution on PVDF ultrafiltration membrane (PM) and modified PVDF ultrafiltration membrane (MPM) is important in understanding the adsorption mechanism of ultrafiltration processes. Effect of variables including adsorption time, initial solution concentration, and temperature were investigated. The Redlich-Peterson equation of the five different isotherm models we chose was the most fitted model, and the R(2) was 0.9487, 0.9765 for PM and MPM, respectively; while, the pseudo-first-order model was the best choice among all the four kinetic models to describe the adsorption behavior of APAM onto membranes, suggesting that the adsorption mechanism was a chemical and physical combined adsorption on heterogeneous surface. The thermodynamic parameters were also calculated from the temperature dependence (Δ(r)G(m)(θ), Δ(r)H(m)(θ), Δ(r)S(m)(θ)), which showed that the process of adsorption is not spontaneous but endothermic process and high temperature favors the adsorption.

Fluid therapy of acute brain edema in children

The clinical experience with a new fluid therapy in children with acute brain edema complicated by infectious disease is reported. The clinical data of a retrospective group of 192 patients and a prospective study of 1,302 and 2,279 patients is summarized. One method of fluid therapy for children with acute brain edema is traditional; fluid intake is restricted to less than 1,200 mL/m(2) daily (60 mL/kg daily). Another method is the new fluid therapy regimen used in our prospective study, in which dehydration and fluid replenishment are individualized. On the first day the fluid intake of patients who survived varied from 40 to 208 mL/kg daily. The mortality rate in the two prospective groups was 19.66% in 1,302 patients and 17.2% in 2,279 patients, significantly lower than the 63.5% in the retrospective group (192 patients) (P <0.001). This result indicates that a wide range of fluid intake for children with acute brain edema is allowable during the first days of treatment. The appropriate dehydration and fluid replenishment should be individualized based on close observation of the patient's condition.