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Objective Graves' disease is the most common autoimmune thyroid disease and its prevalence and clinical manifestations are disparate between females and males. Costimulatory molecules play an essential role in regulating autoimmune responses. The objective of this study was to determine if expression of inhibitory molecules was correlated with treatment by dihydrotestosterone (DHT) in an in vivo BALB/c mouse model of experimental autoimmune Graves' disease.Methods Female BALB/c mice were immunized three times with thyroid stimulating hormone receptor A-subunit encoded by adenovirus to establish a Graves' disease model. Three different doses of DHT or a matching placebo were administered by implantation of slow-release pellets a week before the first immunization. Four weeks after the third immunization, the mice were euthanatized, and then the spleen and thymus were removed. Total thyroxine and free thyroxine levels in serum of mice were detected using a radioimmunoassay kit. Real-time polymerase chain reaction was performed to estimate the expression of costimulatory molecules in lymphocytes from the spleen and thymus. Flow cytometry was used to analyze the percentage of CD4 + T cells in splenic lymphocytes. Quantitative data were compared with unpaired t -tests. Correlation between two variables was analyzed using Analysis of Variance.Results Treatment with DHT can dramatically reduce total thyroxine and free thyroxine levels. Higher expression of programmed death-1 was found in the spleen of Graves' disease mice receiving 5 mg of DHT treatment (0.635±0.296 vs . 0.327±0.212; t =2.714, P =0.014), similarly, T-cell immunoglobulin domain and mucin domain 3 (TIM-3) in both the spleen (1.004±0.338 vs . 0.646±0.314; t =2.205, P =0.022) and the thymus (0.263±0.127 vs . 0.120±0.076; t =3.221, P =0.004) also increased after 5 mg of DHT treatment compared with the parallel placebo model mice. Moreover, the percentage of CD4 + T cells declined in the splenic lymphocytes of Graves' disease mice treated with 5 mg of DHT (19.90%±3.985% vs . 24.05%±2.587%; t =2.804, P =0.012). A significant negative association was observed between expression of TIM-3 in the spleen and serum levels of total thyroxine ( r =-0.7106, P =0.014) as well as free thyroxine ( r =-0.6542, P =0.029).Conclusion This study demonstrates that DHT can ameliorate experimental autoimmune Graves' disease, which may occur by up-regulating expression of programmed death-1 and TIM-3 and inhibiting development of CD4 + T cells.

Quercetin (Q) is one of the most common flavonoids present in roots, stems, leaves, flowers and fruits of most plants. In this study, a quercetin-based fluorescent probe for detecting fluorid ions had been proposed. With good selectivity and sensitivity for fluorid ions, Q-based fluorescent probe was easier to prepare, more eco-friendly and more innoxious compared with traditional fluorescent probe obtained by organic chemistry synthesis operation. There was a major fluorescence emission peak at 500 nm for Q in dimethyl sulfoxide (DMSO) when the excitation wavelength was 390 nm. The changes of fluorescence spectra were investigated before and after adding different anions into Q solution. The fluorescence emission intensity of Q even had no change when adding Cl-，Br-，I-，ClO-4，H2PO-4, respectively. While adding fluorid ions, the fluorescence emission intensity of Q was decreased obviously, which suggested fluorid ions could induce fluorescence quenching of Q in DMSO. And the fluorescence emission intensity of Q-F- system had almost no significant change when adding other anions (Cl-，Br-，I-，ClO-4，H2PO-4), which meant the progress for detecting fluorid ions didn’t be affected by other anions, and Q showed a good selectivity for fluorid ions. The fluorescence titration spectra showed that the fluorescence emission intensity of Q was decreased with the increase of concentration of fluorid ions, and they were in concentration-dependent manner. The fluorescence titration curve exhibited that the Q as fluorescent probe can be applied to the quantification of fluorid ions with a good linearity (R2=0.991), linear range of 1.0～8.0×10-6 mol·L-1 and the detection limit of 1.0×10-7 mol·L-1. Not only the changes appeared in fluorescence spectra, but also the changes appeared in UV-visible spectra, compared with Q absorption spectrum, the location of band at 375 nm had no change after adding Cl-，Br-，I-，ClO-4，H2PO-4, respectively. However, when adding fluorid ions, the band at 375 nm was shifted to 394 nm, and the color of the solution was changed into dark yellow, which revealed the interactions between Q and fluorid ions. The probable mechanism of fluorid ions inducing fluorescence quenching of Q was obtained with 1H NMR spectrum and the changes of fluorescence emission intensity of Q-F- system in different polar solvents (DMSO containing different concentration of water). The interaction mode about Q and fluorid ions in DMSO was related with hydrogen bond. Both experiments suggested that the possible recognition mechanism on fluorid ions was: fluorid ions were destroyed or weakened by original hydrogen bonds, and were promoted charge transfer within quercetin molecule, which resulted in fluorescence intensity decreasing of quercetin. This method was successfully applied in detecting fluorid ions of samples in DMSO with good recovery.

Objective: A clinical chromatographic fingerprinting of 18 standard strains of Mycobacteria commercialized in China by high-performance liquid chromatography approach was developed and improved in this laboratory. A comparison of clinical chromatographic fingerprintings of mycolic acids was carried out., Methods: Mycolic acids were extracted from whole cultured cells of Mycobacteria by biochemical methods, and then samples was prepared for analysis after the mycolic acids were saponified, acidified and derived. The samples were detected by high-performance liquid chromatography under optimum conditions., Results: Using above techniques a clinical chromatographic fingerprinting of Mycolic acids analysis was successfully established. The repeatability of the mycolic acids fingerprinting was evaluated. Coefficient of variation (CV) of chromatographic fingerprinting was between 0.20% - 0.83%., Conclusions: The first clinical chromatographic fingerprinting of 18 standard strains of Mycobacteria in China was established in this laboratory. Mycobacteria can be accurately identified according to chromatographic fingerprinting in a short time. Moreover, there was significant difference between BCG vaccine and Mycobacterium bovis when their peak was compared, which may lead to research of new tools for identifying insidious infection of tuberculosis and for the study of the mechanism of drug tolerance.