Time filter

Source Type

Zhang D.-K.,Lanzhou University | Yu J.-J.,Lanzhou University | Li Y.-M.,Key Laboratory of Digestive System Tumors | Wei L.-N.,Lanzhou University | And 3 more authors.
Mediators of Inflammation

Background. Free radicals and proinflammatory cytokines have been shown to play a critical role in the pathogenesis of ulcerative colitis (UC). Picroliv, a Picrorhiza kurroa derivative, has been demonstrated to have antioxidant and anti-inflammatory effect. The purpose of the study was to investigate the effects of picroliv on experimental model of UC in mice. Materials and Methods. Picroliv was administrated orally by gavage to mice with colitis induced by dextran sulfate sodium (DSS). Disease activity index (DAI), colon length, and histology score were observed. Myeloperoxidase (MPO) activity, and SOD, MDA concentrations were measured by enzyme-linked immunosorbent assay (ELISA) while the expression of cytokine mRNAs was studied by real-time-quantitative polymerase chain reaction and also ELISA. The expression of NF-κB p65 was observed by immunohistochemistry staining and western blotting. Results. A significant improvement was observed in DAI and histological score in mice treated with picroliv, and incerased MPO activity, MDA concentrations, and the expression of IL-1β, TNF-α, and NF-κB p65 in mice with DSS-induced colitis were significantly reduced while decreased SOD level increased following administration of picroliv. Conclusion. The administration of picroliv leads to an amelioration of DSS-induced colitis, suggesting administration of picroliv may provide a therapeutic approach for UC. © 2012 De-Kui Zhang et al. Source

Ye W.,Lanzhou University | Chen Y.,Lanzhou University | Zhou F.,CAS Lanzhou Institute of Chemical Physics | Wang C.,Lanzhou University | Li Y.,Key Laboratory of Digestive System Tumors
Journal of Materials Chemistry

Although Al has a lower redox potential [Al 3+/Al, -1.67 V vs. SHE] than most metallic ions, metal galvanic replacement reactions on pure aluminum foil can be hardly observed because of the existence of the thin layer of aluminum oxide, In this work, we develop a facile, economical and general approach to achieve large-scale production of silver and gold dendrites as well as other metal hierarchical micro/nanostructures (Cu, Pt, Pd, Ni, Co and Zn) on commercial aluminum foil in the presence of NaF or NH 4F. Studies of the galvanic replacement reaction by open circuit potential-time (OCP-t) measurements demonstrate that fluoride plays an important role in etching the alumina layer and thus induces the continuous proceeding of the galvanic replacement reaction. The synthesis process is carried out at room temperature and without any templates, surfactants, or special reagents. The obtained silver and gold dendrites show significantly enhanced SERS signals of a self-assembled monolayer of 2-naphthalenethiol and 4-mercaptobenzoic acid, and also could effectively catalyze the reduction reaction of 4-nitrophenol and 2-nitrophenol at room temperature. © 2012 The Royal Society of Chemistry. Source

Zhang L.-L.,Lanzhou University | Li P.,Lanzhou University | Li P.,Key Laboratory of Digestive System Tumors | Li Y.-M.,Lanzhou University | And 2 more authors.
Drug Development and Industrial Pharmacy

The aim of this study was to use alginate-chitosan (Alg-CS) hydrogel beads for developing an oral water-soluble drug delivery system, occupying pH-sensitive property and superparamagnetic. Matrine as a model drug was loaded in Alg-CS hydrogel beads to study the release character of the delivery system. The amount of matrine released from the beads was relatively low in pH 2.5 over 8h (34.90%), but nearly all of the initial drug content was released in simulated intestinal fluid (SIF, pH 6.8) within 8h. The results demonstrated that Alg-CS hydrogel beads possess unique pH-dependent swelling behaviors. In addition, the magnetic beads were characterized by Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffractometry and vibrating-sample magnetometry. Magnetometer measurements data suggested that Alg-CS beads also had superparamagnetic property as well as fast magnetic response. It can be expected that the beads can deliver and release encapsulated anticancer agent at the tumor by the weak magnetic field, and hence could be potential candidates as an orally administered drug delivery system. © 2012 Informa Healthcare USA, Inc. Source

Liu T.,Lanzhou University | Liu T.,Key Laboratory of Digestive System Tumors | He W.,Lanzhou University | Yan C.,Lanzhou University | And 2 more authors.
Toxicology and Industrial Health

The roles of reactive oxygen species (ROS) and mitochondrial damage in the cadmium (Cd)-induced injury of liver cells were studied by using N-acetyl-L-cysteine (NAC) and acetyl-L-carnitine hydrochloride (ALCAR). After exposure of experimental rats to cadmium (Cd) for 16 h, mitochondrial membrane potential (MMP), ROS production, glutathione peroxidase (GSH-Px) activity, glutathione (GSH) content, malondialdehyde (MDA) content and DNA single-strand break (DNA-SSB) were analyzed. Loss of MMP, increase of ROS production, inhibition of GSH-Px activity, elevation of GSH content, rise of MDA content and DNA-SSB level suggest the participation of ROS and mitochondrion in Cd-induced injury of liver cell. NAC pretreatment attenuated oxidative stress, reversed the decline in GSH-Px activity and reduced GSH and MDA levels significantly. However, Cd-induced loss in MMP was significantly exacerbated by NAC. For another, ALCAR did not perform as well as NAC in terms of reducing ROS production, restoring GSH-Px activity and reducing GSH content. Nevertheless, it significantly improved the recovery of MMP and reduction of MDA content. In addition, conspicuous DNA damage was observed in the samples treated with NAC or ALCAR, indicating Cd could attack DNA through other pathways. These results suggest that oxidative stress or mitochondrial impairment plays a main role in different injuries respectively. © The Author(s) 2011. Source

He W.-T.,Lanzhou University | He W.-T.,Key Laboratory of Digestive System Tumors | Liu T.,Lanzhou University | Liu T.,Key Laboratory of Digestive System Tumors | And 3 more authors.
Asian Pacific Journal of Cancer Prevention

Background: The Chinese Hui ethnic group has diverse origins, including Arab, Persian, Central Asian, and Mongol. The standardized mortality rate of gastric cancer in the Hui population is higher than the overall Chinese population. In this study, we investigated whether COX-2-765G>C polymorphism, an extensively studied polymorphism, contributes to gastric cancer and its precursor lesions (GPL) in the Chinese Hui ethnic group. Materials and Methods: COX-2-765G>C polymorphism was determined by pyrosequencing in 100 gastric cancer cases, 102 gastric cancerand its precursor lesions cases and 105 controls. Data were statistically analyzed using Chi-square tests and logistic regression models. Results: Among the Chinese Hui ethnic group COX-2 -765 C allele carriers were at increased risk for gastric cancer (OR=1.977, 95%CI=1.104-3.541). We also found an interaction between COX-2 -765 C carriers and Helicobacter pylori infection and eating pickled vegetables. Conclusions: Our findings suggest a multi-step process of gene-environment interaction contributes to gastric carcinogenesis. Source

Discover hidden collaborations