An electrochemical sensor based on molecularly imprinted poly(o-phenylenediamine) for the detection of thymol.

A molecularly imprinted electrochemical sensor was facilely fabricated for the detection of thymol (THY). o-Phenylenediamine (oPD) was used as the functional monomer and electropolymerized on the surface of the glassy carbon electrode (GCE) by using THY as the templates. After the THY templates were removed with 50 % (v/v) ethanol, imprinted cavities complementary to the templates were formed within the poly(o-phenylenediamine) (PoPD) films. The resultant molecularly imprinted PoPD/GCE (MI-PoPD/GCE) was used for the detection of THY, and a wide linear range from 0.5 to 100 µM with a low limit of detection (LOD) of 0.084 µM were obtained under the optimal conditions. The developed MI-PoPD/GCE also displays high selectivity, reproducibility and stability for THY detection. Finally, the content of THY in the real samples was accurately determined by the as-fabricated MI-PoPD/GCE, demonstrating its high practicability and reliability.

Rapid and visual detection of dengue virus using recombinase polymerase amplification method combined with lateral flow dipstick.

Dengue virus (DENV), a member of the genus Flavivirus within the family Flaviviridae, is one of the most significant mosquito-borne viruses that causing dengue fever in human. A rapid diagnostic would be helpful to detect DENV infection in a timely manner. In the last decade, recombinase polymerase amplification (RPA) technique has been experiencing rapid development and widely employed to detect various other pathogens. In present study, a reverse transcription RPA (RT-RPA) assay combined with lateral flow dipstick (LFD) was established for rapid detection of DENV. The assay could detect DENV-1, -2, -3 and -4. The minimal detection limit of the RT-RPA-LFD assay was 10 copies RNA molecules. The assay was DENV-specific since it had no non-specific reactions with other common human pathogens. The clinical performance of the RT-RPA assay was validated using 120 clinical samples. The coincidence rate between RT-RPA-LFD and qRT-PCR for the clinical samples was 100%, indicating the RT-RPA-LFD assay had good diagnostic performance on clinical samples. The RT-RPA-LFD assay required no sophisticated instrument, providing a possible solution for DENV diagnosis in recourse-limited settings where DENV infection is epidemic.

Development of a reverse transcription recombinase polymerase amplification assay for rapid detection of human respiratory syncytial virus.

Respiratory syncytial virus (RSV) is one of the most important causative agents that causing respiratory tract infection in children and associated with high morbidity and mortality. A diagnostic method would be a robust tool for identification of RSV infection, especially in the resource-limited settings. Recombinase polymerase amplification (RPA) is a novel isothermal amplification technique which has been widely employed to detect human/animal pathogens. In present study, a probe-based reverse transcription RPA (RT-RPA) assay was established for the detection of RSV. The primers and probe were designed based on the sequences of the conserved nucleocapsid (N) gene. The minimal detection limit of the RT-RPA assay for the detection of RSV B was 19 copies of RNA molecules at 95% probability, whereas the detection limit for RSV A was 104 copies molecule. The assay was RSV-specific since it had no non-specific reactions with other common human pathogens. The clinical performance of the RT-RPA assay was validated using 188 nasopharyngeal aspirates (NPAs). The nucleic acid extraction of the samples was performed by use of the magnetic bead-based kit which didn't require the heavy and expensive centrifuge. The coincidence rates between RT-RPA and qRT-PCR for the clinical samples was 96%, indicating the RT-RPA assay had good diagnostic performance on clinical samples. The real-time RT-RPA assay combined with the manual genome extraction method make it potential to detect clinical samples in field, providing a possible solution for RSV diagnosis in remote rural areas in developing countries.

[Therapeutic window analysis of Tripterygium wilfordii processed by liquorice: an instantiation using allergic contact dermatitis].

The present study was aimed to explore the dose-toxicity-effect relationship of Tripterygium wilfordii Hook f( TW) processed by liquorice,to establish the safe and effective therapeutic window,and further to provide scientific reference for the clinical use of TW. The toxicity and anti-inflammatory effect of six doses of raw TW and TW processed by liquorice( 0. 78,1. 56,3. 12,6. 24,12. 48,15. 60 g·kg-1) in 1-fluoro-2,4-dinitrobenzene( DNFB)-induced allergic contact dermatitis( ACD) model were mainly examined by histopathology and serum biochemistry. The liver biochemical parameters including ALT and AST,related inflammatory factors including TNF-α and IL-2,together with liver index,kidney index and the other pharmacodynamic indicators,were examined and compared. The results showed that compared with the control group,the serum levels of TNF-α and IL-2 of the model group were significantly increased( P<0. 01),which proved that the ACD model was successful. The comprehensive analysis of liver biochemical indexes,serum inflammatory factors and the other indexes showed that the safe and effective therapeutic window of TW processed by liquorice was 3. 12-12. 48 g·kg-1. The results showed the therapeutic window of TW processed by liquorice was much broader than that of raw TW. And it could provide scientific reference for the clinical rational use of TW.

[Preliminary screening of biomarkers for curcumin's antidepressant effect based on metabonomics method].

To screen potential biomarkers of curcumin related to treating depression rats by using metabolomics means, so as to explore the antidepressant action mechanism of curcumin. The healthy male SD rats were randomly divided into four groups. Chronic unpredictable mild stress (CUMS) stimulation was conducted for modeling for 2 weeks, and then curcumin (200 mg•kg⁻¹) or venlafaxine (40 mg•kg⁻¹) was given by gavage administration. The blank group and model group rats were given with the same volume of 1% CMCNa normal saline, once per day for two weeks. The rats serum for each group was collected and LC/MS-IT-TOF method was used to characterize the metabolic differences. Also multivariate statistical analysis was used to screen possible potential biomarkers and analyze the possible metabolic pathways. After administration of curcumin and venlafaxine respectively, the depression indexes of CUMS model rats were all improved significantly (P<0.05), but there were no significant differences between curcumin and venlafaxine groups. In PCA and PLS-DA analysis after curcumin or venlafaxine intervention on CUMS model group rats, the small molecule metabolites level reflects a normal trend, and particularly for the curcumin group. Through metabonomics technology, 11 biomarkers associated with curcumin antidepressant effect were screened, and at the same time seven metabolic pathways were involved. The results showed that curcumin had antidepressant effects, which was evident in both macro and micro levels, comparable with positive drug of venlafaxine. The antidepressant effect of curcumin may be associated with the glycerol phospholipid metabolism, linoleic acid metabolism, pentose and glucuronic acid ester and ether lipid metabolism, but still need further exploration in the future.

[Preliminary research on effect of licorice-processed Tripterygium wilfordii on reducing liver toxicity].

To explore the effect of the licorice-processed Tripterygium wilfordii on reducing the liver toxicity. In animal experiments, the liver toxicity of T. wilfordii was evaluated both before and after processing, and the differences in liver tissue biopsy, serum biochemical indexes and inflammatory cell factor among blank group, T. wilfordii group and licorice-processed T. wilfordii group were observed. Liver tissue biopsy results showed that liver tissue injury was obvious in T. wilfordii group, and no obvious injury was found in licorice-processed T. wilfordii group. As compared with the blank group, the levels of AST, ALT and CRE were significantly increased (P<0.01), UREA was increased (P<0.05), and ALB level was significantly decreased (P<0.01) in the T. wilfordii group. As compared with T. wilfordii group, the levels of AST, ALT, CRE, and UREA were decreased (P<0.01), while ALB was increased (P<0.01) in the licorice-processed T. wilfordii group. The results of inflammatory factors in rats showed that the levels of IL-1ß, IL-6, and TNF-α in T. wilfordii group were significantly higher than those in blank group (P<0.01); the levels of IL-1ß, IL-6, and TNF-α in licorice-processed T. wilfordii group were significantly lower than those in T. wilfordii group (P<0.01). Overall, licorice processing of T. wilfordii can effectively reduce the liver toxicity and reduce the liver injury caused by T. wilfordii. The experiment can provide reference for the clinical rational use of the T. wilfordii, and provide data support for the studies on reducing the liver toxicity of T. wilfordii by licorice processing.

[Correlation between hepatic immunological markers and virus genotype in patients with chronic hepatitis C].

OBJECTIVE: To investigate the hepatic expression of immunological markers relevant to a cytotoxic response in relation to viral genotype. METHODS: The frozen liver biopsies were obtained from 28 HF genotyped patients and made the sections stained. The morphometry was used to analyze the major histocompatibility complex class I (MHC-I), CD8, beta(2)-microglobulin (beta(2) -mG), HFE and CD68 in the stained sections. Biopsy data of response to therapy with interferon were available in 18 cases. RESULTS: CD8+ was usually clustered together and localized in portal tracts and sinusoids, and seen to interact with MHC I positive lining cells. MHC-I and beta(2) -mG were expressed mainly in endothelial and Kupffer cells. HFE was expressed in most round and dendritic CD68+ cells. Patients with virus genotype 3a had higher hepatic MHC-I and HFE expression, and a better sustained response to interferon (IFN) therapy than patients without. CONCLUSION: The MHC-I expression in the liver of patient with chronic hepatitis C virus infection seems to relate to viral-genotype. The hepatic MHC-I and HFE expression are higher in patients with virus genotype 3a than that in patients with non-3a genotype.