The management of municipal solid waste in Hong Kong : a study of civic engagement strategies

published_or_final_versionPolitics and Public AdministrationMasterMaster of Public Administratio

Recent advances in the compound-oriented and pattern-oriented approaches to the quality control of herbal medicines

The current approaches to the quality control of herbal medicines are either compound-oriented or pattern-oriented, the former targeting specific components with some known chemical properties and the latter targeting all detectable components. The marker approach uses specific chemical compounds with known molecular structures, while the multi-compound approach uses both chemical compounds with known structures and those with partial chemical information e.g. retention times, mass spectra and ultraviolet spectra. Apart from chromatographic techniques, new techniques such as oscillating and electrochemistry fingerprints have been developed for quality control. Chemometric resolution methods are widely used for component deconvolution and data comparison. Pattern recognition techniques are used for authentication of herbal medicines

rad21 Is Involved in Corneal Stroma Development by Regulating Neural Crest Migration

Previously, we identified RAD21(R450C) from a peripheral sclerocornea pedigree. Injection of this rad21 variant mRNA into Xenopus laevis embryos disrupted the organization of corneal stroma fibrils. To understand the mechanisms of RAD21-mediated corneal stroma defects, gene expression and chromosome conformation analysis were performed using cells from family members affected by peripheral sclerocornea. Both gene expression and chromosome conformation of cell adhesion genes were affected in cells carrying the heterozygous rad21 variant. Since cell migration is essential in early embryonic development and sclerocornea is a congenital disease, we studied neural crest migration during cornea development in X. laevis embryos. In X. laevis embryos injected with rad21 mutant mRNA, neural crest migration was disrupted, and the number of neural crest-derived periocular mesenchymes decreased significantly in the corneal stroma region. Our data indicate that the RAD21(R450C) variant contributes to peripheral sclerocornea by modifying chromosome conformation and gene expression, therefore disturbing neural crest cell migration, which suggests RAD21 plays a key role in corneal stroma development

A Metabolomics Study on the Bone Protective Effects of a Lignan-Rich Fraction From Sambucus Williamsii Ramulus in Aged Rats

The lignan-rich fraction (SWR) of Sambucus Williamsii Ramulus, a folk herbal medicine in China for treatment of bone diseases, has previously reported to exert protective effects on bone without exerting uterotrophic effects in ovariectomized (OVX) mice. The aim of the present study was to identify the potential metabolites and the associated metabolic pathways that contribute to the beneficial effects of SWR on bone in vivo. Aged female Sprague Dawley rats (9 months old) were either sham-operated or ovariectomized for 12 weeks, before receiving treatment for another 12 weeks with the following treatment groups (n = 12 each): vehicle (Sham), vehicle (OVX), Premarin (130 μg/kg) or low (57 mg/kg), medium (114 mg/kg), and high (228 mg/kg) doses of SWR. The results showed that SWRH significantly suppressed bone loss, improved bone micro-architecture and increased bone strength on tibia without stimulating uterus weight gain in OVX rats. Premarin exerted similar bone protective effects as SWRH but elicited uterotrophic effects in OVX rats. The metabolic profiles of serum samples were analyzed by using ultra-performance liquid chromatography quadrupole time-of flight mass spectrometry and gas chromatography time-of flight mass spectrometry, and the metabolites that were significantly altered were identified by multivariate statistical analysis. Our study indicated that SWRH effectively restored the changes of 26 metabolites induced by estrogen-deficiency in OVX rats, which related to lipids, amino acids, tryptophan metabolisms, and anti-oxidative system. A subsequent validation showed that the serum level of superoxide dismutase and catalase were indeed up-regulated, while the serotonin level in a tryptophan hydroxylase 1 (TPH1) high expressing cells (rats RBL-2H3 cells) was down regulated after treatment with SWR. The results also suggested that the gut-microbiota may play an important role on the bone protective effects of SWR. The current study provides insight for understanding the unique mechanism of actions of SWR that might be involved in achieving bone protective effects in vivo

Shugan Xiaozhi Decoction Attenuates Nonalcoholic Steatohepatitis by Enhancing PPAR α

This study aimed to investigate the effects of Shugan Xiaozhi decoction (SX) on nonalcoholic steatohepatitis (NASH) induced by high-fat diet in rats. The rats were randomly divided into 6 groups, namely, control, model, fenofibrate, and three different dosage of SX (10, 20, and 40 g/kg/day, p.o.). After establishing the NASH model, at 8 weeks of the experiment, treatments were administrated intragastrically to the fenofibrate and SX groups. All rats were killed after 4 weeks of treatment. Compared with the model group, alanine aminotransferase (ALT), aspartate aminotransferase (AST), free fatty acid (FFA), total cholesterol (TC), triacylglycerol (TG), and low-density lipoprotein cholesterol (LDL) serum in the serum were significantly reduced in all SX treatment groups in a dose-dependent manner. Evidence showed that SX could protect the liver by upregulating the gene and protein expressions of peroxisome proliferator-activated receptor alpha (PPARα) and liver fatty acid binding protein (L-FABP) in a dose-dependent manner. Chemical constituents of SX were further analyzed by ultraperformance liquid chromatography coupled with electrospray ionization mass spectrometry (UPLC-ESI-MS) and 30 chemicals in the ethanolic extract were tentatively identified. To conclude, our results clearly indicated that SX could protect liver functions and relieve hepatic steatosis and inflammation

MicroRNA let-7 suppresses nasopharyngeal carcinoma cells proliferation through downregulating c-Myc expression

Aims: This study aimed at evaluating the potential anti-proliferative effects of the microRNA let-7 family in nasopharyngeal carcinoma (NPC) cells. In addition, the association between let-7 suppression and DNA hypermethylation is examined. Materials and methods: Levels of mature let-7 family members (-a,-b,-d,-e,-g, and-i) in normal nasopharyngeal cells (NP69 and NP460) and nasopharyngeal carcinoma cells (HK1 and HONE1) were measured by real-time quantitative PCR. Cell-proliferation assay and c-Myc immunohistochemical staining were performed on NPC cells transfected with let-7 precursor molecules. In addition, expression changes in let-7 family members in response to demethylating agents (5-azacytidine and zebularine) were also examined. Results: In comparison with the normal nasopharyngeal cells, let-7 (-a,-b,-d,-e,-g, and-i) levels were reduced in nasopharyngeal carcinoma cells. Ectopic expression of the let-7 family in nasopharyngeal carcinoma cells resulted in inhibition of cell proliferation through downregulation of c-Myc expression. Demethylation treatment of nasopharyngeal carcinoma cells caused activation of let-7 expression in poorly differentiated nasopharyngeal carcinoma cells only. Conclusion: Our results suggested that miRNA let-7 might play a role in the proliferation of NPC. DNA methylation is a potential regulatory pathway, which is affected when let-7 is suppressed in NPC cells. However, the extent of DNA hypermethylation/hypomethylation in regulating let-7 expression requires further elucidation. © The Author(s) 2010. This article is published with open access at Springerlink.com.published_or_final_versionSpringer Open Choice, 21 Feb 201

Upregulation of the Wnt Co-Receptor LRP6 Promotes Hepatocarcinogenesis and Enhances Cell Invasion

Background: Activation of the Wnt/b-catenin signaling pathway plays a crucial role in hepatocellular carcinoma (HCC). Lowdensity lipoprotein (LDL) receptor-related protein-6 (LRP6) is one of the co-receptors of the Wnt/b-catenin pathway and forms a signaling complex with Wnt ligand and Frizzled receptor to activate downstream signaling. However, the role of LRP6 in hepatocarcinogenesis is unclear. In this study, we examined its expression and roles in human HCC. Methodology/Principal Findings: Using real-time quantitative RT-PCR, we found that LRP6 was frequently (45%) overexpressed in human HCCs (P = 0.003). In vitro studies showed that ectopic expression of LRP6 increased the protein level of b-catenin. Moreover, overexpression of the full-length and constitutively active LRP6, respectively, activated the WNT/b-catenin signaling pathway, as shown by the TCF/b-catenin reporter assay. With regard to the effects of LRP6 overexpression in HCC cells, stable overexpression of the constitutively active LRP6 in BEL-7402 HCC cells enhanced cell proliferation, cell migration, and invasion in vitro as well as tumorigenicity in nude mice. Conclusions/Significance: Our findings indicate that overexpression of LRP6 contributes to the hyperactivation of the Wnt