Curcumin's Dose-Dependent Attenuation of Gastric Cancer Cell Progression Via the PI3K Pathway Blockade.

Background: Gastric cancer stands as a primary cause of cancer-related deaths worldwide, making the discovery of new therapeutic agents essential for enhancing treatment outcomes. Curcumin, a polyphenolic compound found in turmeric (Curcuma longa), has demonstrated potential in multiple cancer types due to its anti-cancer characteristics. This research aimed to examine the impact of curcumin on gastric cancer cell growth, migration, and invasion, as well as its influence on the phosphoinositide 3-kinase (PI3K) signaling cascade. Methods: Gastric cancer cell lines were exposed to varying curcumin concentrations, followed by assessments of cell viability, migration, and invasion. Furthermore, gene and protein expression levels associated with the PI3K signaling cascade were evaluated using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Results: The findings revealed a dose-dependent decrease in cell viability, migration, and invasion in gastric cancer cells treated with curcumin. Additionally, curcumin administration led to the downregulation of key genes and proteins within the PI3K signaling process, such as PI3K, Akt, and mTOR. Conclusion: These findings propose that curcumin may exercise its anti-cancer effects on gastric cancer cells, partly by suppressing the PI3K signaling pathway. This study's outcomes support curcumin's potential as a therapeutic agent for gastric cancer and encourage further exploration of its underlying molecular mechanisms and in vivo effectiveness.

Modified Bamboo Charcoal as a Bifunctional Material for Methylene Blue Removal.

Biomass-derived raw bamboo charcoal (BC), NaOH-impregnated bamboo charcoal (BC-I), and magnetic bamboo charcoal (BC-IM) were fabricated and used as bio-adsorbents and Fenton-like catalysts for methylene blue removal. Compared to the raw biochar, a simple NaOH impregnation process significantly optimized the crystal structure, pore size distribution, and surface functional groups and increase the specific surface area from 1.4 to 63.0 m2/g. Further magnetization of the BC-I sample not only enhanced the surface area to 84.7 m2/g, but also improved the recycling convenience due to the superparamagnetism. The maximum adsorption capacity of BC, BC-I, and BC-IM for methylene blue at 328 K was 135.13, 220.26 and 497.51 mg/g, respectively. The pseudo-first-order rate constants k at 308 K for BC, BC-I, and BC-IM catalytic degradation in the presence of H2O2 were 0.198, 0.351, and 1.542 h-1, respectively. A synergistic mechanism between adsorption and radical processes was proposed.

Sensitive Detection of Telomerase Based on Hybridization Chain Reaction-assisted Multiple Signal Amplification / 分析化学

A new electrochemical method for telomerase activity assay was developed on the basis of hybridization chain reaction ( HCR)-assisted multiple signal amplification, aiming at improving the sensitivity and specificity of telomerase assay. The experiments utilized HeLa cells as original source of the telomerase in the electrochemical studies. The telomerase primer was firstly self-assembled on the surface of gold electrode. The telomerase catalyzed the elongation of the primer, producing the complementary sequences of hairpin probe H1. In this case, HCR was then initiated by interacting with two hairpin probes H1 and H2. Because both H1 and H2 were modified by biotin, horseradish peroxidase could be captured on the electrode surface through the high-affinity interaction between biotin and streptavidin, catalyzing the oxidation of o-phenylenediamine to produce 2,3-diaminophenazine. Therefore, the telomerase assay was realized by tracing the electrochemical signals with differential pulse voltammetry. This electrochemical method was of high efficiency and feasibility for detecting telomerase activity, and could trace the telomerase activity down to 10 cells/mL HeLa cells with a wide linear range. Besides, it could also easily distinguish the target enzyme from the control proteins with high specificity.

Assessing the effect of pit and fissure sealing on 733 six-year-teeth four years later / 口腔疾病防治

Objective@# Assessing the effect of pit and fissure sealing on children’mandibular first molar in four years follow-up.@*Methods@#The second grade pupils of five primary schools in Guangzhou were given pit and fissure sealing, 733 teeth were performed pit and fissure sealant. The retention rate of the sealant and caries incidence of the mandibular first molar were analysed in four years follow-up. @*Results @# In four years follow-up, the retention rate of mandibular first molar was 57.16%. In terms of the caries incidence, the sealing group was 9.82%, while the unsealing group was 15.77%(χ2 = 7.045, P < 0.05). The decrease rate of caries in the sealing group was 37.73%, the caries incidence for the shallow pit and fissure group was 7.76%, no statistical differentce could be found two groups (χ2 = 0.844,P = 0.358).@*Conclusion@#Caries incidence of mandibular first molar obviously decreased 4 years later after the pit and fissure sealing.

Facile synthesis of benzothiazoles via cascade reactions of 2-iodoanilines, acid chlorides and Lawesson's reagent.

In the presence of Lawesson's reagent, metal-free one-pot cascade reactions of 2-iodoanilines with acid chlorides proceeded smoothly leading to 2-substituted benzothiazoles in good to excellent yields under mild conditions. Three steps were involved in the reaction process: (1) 2-iodoanilines reacted with acid chlorides to afford benzamides, (2) benzamides transferred to benzothioamides in the presence of Lawesson's reagent, and (3) intramolecular cyclization of benzothioamides generated the expected benzothiazoles.

[Molecular cloning and expression of alcohol dehydrogenase gene of Phanerochaete chrysosporium].

When Phanerochaete chrysosporium is grown under oxygen-limited condition, ethanol is one of the important metabolites. In order to understand the metabolic mechanism of P. chrysosporium grown under oxygen-limited condition, a cDNA sequence (1 071 bp) designated "PCAdh1" encoding an alcohol dehydrogenase (ADH) was cloned from the filamentous white-rot fungus P. chrysosporium. PCAdh1 gene encodes a protein of 356 amino acid residues. Although the catalytic domain and coenzyme-binding domain were highly conserved, the protein sequence of PCAdh1 showed a low level of similarity to other known ADH. The recombinant PCAdh1 protein was expressed in Escherichia coli and its enzyme activity was detected. The protein was purified and used to prepare antibody. Semi-quantitative RT-PCR and Western blot demonstrated that the expression level of PCAdh1 in P. chrysosporium remained stable despite the lowered oxygen content, indicating that the gene expression is constitutive. But with the reduction of oxygen content, the overall activity of ADH from the crude mycelia proteins was increased during the growing periods, implying that the expression of other Adh genes in P. chrysosporium is inductive.

[In situ raman spectroscopic study on the oxidation of HCHO on a roughened platinum electrode].

The electrooxidation behavior of HCHO on a roughened platinum electrode was studied by cyclic voltammetry. Two factors that influence the electrooxidation behavior of HCHO, i.e. the concentration of the supporting electrolyte and the structure of the electrode surface were taken into account. The dissociative adsorption behavior of HCHO on a roughened platinum electrode was investigated by confocal microprobe Raman spectroscopy in-situ, and the spontaneous dissociative adsorption behavior of HCHO on a roughened platinum electrode was found by CV and was confirmed at the molecule level by in-situ Raman spectra.