Simultaneous separation and indirect ultraviolet detection of chlorate and perchlorate by pyridinium ionic liquids in reversed-phase liquid chromatography.

A novel approach for the simultaneous separation and indirect ultraviolet detection of chlorate and perchlorate using pyridinium ionic liquids as mobile phase additives in reversed-phase liquid chromatography was developed. Pyridinium ionic liquids and imidazolium ionic liquids as the mobile phase additives were compared. The effects of pyridinium ionic liquids, methanol, column temperature, and detection wavelength on the separation and detection of chlorate and perchlorate were investigated. The role of ionic liquids, retention rules and relevant mechanisms were discussed. Pyridinium ionic liquids mainly acted as ultraviolet absorption reagent and ion-pair reagent. The successful separation and indirect ultraviolet detection of chlorate and perchlorate were achieved by using a common reversed-phase column, 0.2 mmol/L N-octylpyridinium bromide aqueous solution/methanol (90/10, v/v) as mobile phase and at the detection wavelength of 210 nm. The retention times of chlorate and perchlorate were 30.51 and 37.06 min, respectively. The detection limits of chlorate and perchlorate were 0.16 and 0.29 mg/L, respectively. The linearity and repeatability of the method were satisfactory. The approach was used to the analysis of river water samples with accurate and reliable results. This method is easy to popularize due to the use of common reversed-phase column and ultraviolet detector in liquid chromatography.

CD147 modulates the differentiation of T-helper 17 cells in patients with rheumatoid arthritis.

The role of CD147 in regulation of rheumatoid arthritis (RA) is not fully elucidated. The aim of this study was to investigate the effect of cell-to-cell contact of activated CD14+ monocytes with CD4+ T cells, and the modulatory role of CD147 on T-helper 17 (Th17) cells differentiation in patients with RA. Twenty confirmed active RA patients and twenty normal controls were enrolled. CD4+ T cells and CD14+ monocytes were purified by magnetic beads cell sorting. Cells were cultured under different conditions in CD4+ T cells alone, direct cell-to-cell contact co-culture of CD4+ and CD14+ cells, or indirect transwell co-culture of CD4+ /CD14+ cells in response to LPS and anti-CD3 stimulation with or without anti-CD147 antibody pretreatments. The proportion of IL-17-producing CD4+ T cells (defined as Th17 cells) was determined by flow cytometry. The levels of interleukin (IL)-17, IL-6, and IL-1ß in the supernatants of cultured cells were measured by ELISA. The optimal condition for in vitro induction of Th17 cells differentiation was co-stimulation with 0.1 µg/mL of LPS and 100 ng/mL of anti-CD3 for 3 days under direct cell-to-cell contact co-culture of CD4+ and CD14+ cells. Anti-CD147 antibody reduced the proportion of Th17 cells, and also inhibited the productions of IL-17, IL-6, and IL-1ß in PBMC culture from RA patients. The current results revealed that Th17 differentiation required cell-to-cell contact with activated monocytes. CD147 promoted the differentiation of Th17 cells by regulation of cytokine production, which provided the evidence for pathogenesis and potential therapeutic targets for RA.

Elevated circulating Th17 and follicular helper CD4(+) T cells in patients with rheumatoid arthritis.

It remains not fully elucidated the potential functions of Th17 cells and follicular helper T (Tfh) cells and secreting cytokines in the pathogenesis of rheumatoid arthritis (RA) and their association with disease activity. In this study, the frequencies of Th17 and Tfh cells were determined by flow cytometry, and the levels of interleukin (IL)-17, IL-21, and IL-22 were measured by ELISA in RA patients with different disease activities. The dynamic changes of cell subsets were also detected in response to disease-modify antirheumatic drugs (DMARDs) therapy. The percentages of CD3(+) CD4(+) IL-17A(+) (Th17) cells and CD3(+) CD4(+) CXCR5(+) ICOS(high) (Tfh) cells, as well as the concentrations of IL-17, IL-21, and IL-22 were significantly elevated in RA patients than those in healthy individuals. Furthermore, Tfh cells, IL-21, and IL-22 in the serum was positively correlated with the values of disease activity score. Concentrations of IL-21 and IL-22 in the serum were remarkably reduced following the DMARDs therapies. Our data suggested that Th17 cells, Tfh cells as well as the secreting cytokines may be involved in the pathogenesis of RA. The frequency of circulating Tfh cells and the productions of IL-21 and IL-22 were associated with the disease activity of RA patients, and might be potential therapeutic targets for treatment of RA.

Overexpression of STAT3 potentiates growth, survival, and radioresistance of non-small-cell lung cancer (NSCLC) cells.

OBJECTIVE: Activation of signal transducer and activator of transcription 3 (STAT3) play important roles in tumorigenesis and tumor progression. The overexpression of STAT3 has been found in various malignancies including non-small-cell lung carcinoma (NSCLC). The purpose of this study was to explore the correlation between overexpression of STAT3 gene and growth, survival, and radiosensitivity of NSCLC cells. METHODS: Subclones using vector-based short hairpin RNA (shRNA) were established. RT-PCR and Western blot assays were performed to detect the expression of STAT3 mRNA and protein in untransfected or stably transfected NSCLC cells. Then, MTT and soft agar colony assays were performed to determine the effect of STAT3 inhibition on in vitro growth of NSCLC cells. Hoechst staining assay was performed to analyze the effect of STAT3 inhibition on apoptosis of NSCLC cells. Additionally, clonogenic survival assays were performed to detect the effect of STAT3 inhibition on in vitro radiosensitivity of NSCLC cells. Finally, to examine the effect of pSUPER-shSTAT3 on proliferation and radiosensitivity in vivo, a subcutaneous (s.c.) tumor formation assay in nude mice was performed. RESULTS: We successfully established two stable transfected cell lines (A549/shSTAT3 and SK-MES-1/shSTAT3) in which the expression of STAT3 mRNA and protein was down-regulated. Those two stable subclones showed a significantly dramatic reduction in colony-forming ability and proliferation not only in vitro but also in vivo. The apoptotic rates of A549/shSTAT3 and SK-MES-1/shSTAT3 cells increased to 19.2% and 16.4%, respectively. Moreover, shRNA-mediated STAT3 inhibition could also significantly enhance radiosensitivity of NSCLC cells both in vitro and in vivo. CONCLUSION: Together, the overexpression of STAT3 is correlated with growth, survival, and radioresistance of NSCLC cells, and STAT3 might be a molecular therapeutic target for gene therapy or radiosensitization of NSCLC.