ABSTRACT
A new sensitive method for detection of cumulative radon radiation based on the lead was established. PS2.M which stabilized by K+with hemin as a co-factor exhibits superior peroxidase-like activity, and can effectively catalyze the H2O2-mediated oxidation of TMB. In the presence of Pb2+, K+-stabilized PS2.M DNAzymes are induced to undergo a conformational change,because Pb2+has a higher efficiency with regard to stabilizing G-quadruplexes than K+, accompanied by a decrease of catalytic activity and a sharp decrease of readout signal. In the work, a novel"turn-off"model of colorimetry-Pb2+biosensor based on superior peroxidase-like activity of G-quadruplex for Pb2+analysis was developed. The fading degree of reaction system (△A value) was linearly related to Pb2+concentration in the range of 5. 0×10-9-1. 8× 10-7mol/L. The linear regression equation was △A=0.36+0.13C (10-8mol/L), with R=0.9987. The detection limits of lead and radon were 3.76 nmol/L(S/N=3) and 1.96×103Bq·h/m3(S/N=3), respectively. The method exhibited good selectivity, high sensitivity and convenient operation, and could avoid the radioactive hazard in determination of the radon in environment.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the cytotoxic effects of ampelopsin sodium (Amp-Na) and carboplatin (CBP) used alone or in combination on human non-small cell lung cancer (NSCLC) cells SPC-A1 in vitro and its related mechanism.</p><p><b>METHODS</b>Cytotoxic effects were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. The synergistic effects of the drugs were calculated with coefficient of drug interaction (CDI). Cell cycle was determined by flow cytometry (FCM). The levels of p53, p21, cyclinE, cyclinD1, and phosphorylated cyclin-dependent kinase-2 (p-CDK2) were evaluated by Western blot.</p><p><b>RESULTS</b>Amp-Na (6.25-200 μg/mL) and CBP (3.13-100 μg/mL) alone exhibited prominent cytotoxic activity in a concentration-dependent manner on SPC-A1 cells with 50% inhibitive concentration values of 57.07±14.46 and 34.97±6.30 μg/mL, respectively. Drug combinations were associated with significantly higher cytotoxic effects than each drug alone (P<0.05 or 0.01). The CDI analysis confirmed the synergy of Amp-Na and CBP on inhibiting cancer cell viability across a wide concentration range (CDI <1). FCM and Western blot showed that synergistic cytotoxic effects of Amp-Na and CBP were related to Garrested which mainlym ediated by p 21 through the inhibition of CDK2 activity independent of the p53 tumor suppressor pathway.</p><p><b>CONCLUSIONS</b>Amp-Na exhibits anticancer activities and enhances the antitumor activities of CBP through up-regulation of p21 and inhibition of CDK2 activity in human NSCLC cells SPC-A1. These results suggest that Amp-Na may be applied to enhance the anticancer action of CBP.</p>
Subject(s)
Humans , Antineoplastic Combined Chemotherapy Protocols , Pharmacology , Carboplatin , Pharmacology , Carcinoma, Non-Small-Cell Lung , Drug Therapy , Pathology , Cell Cycle , Cell Line, Tumor , Cell Proliferation , Drug Synergism , Flavonoids , Pharmacology , Lung Neoplasms , Drug Therapy , PathologyABSTRACT
OBJECTIVE: To provide references for the quality evaluation of generic drug in China. METHODS: The process of reevaluation of generic drug in Japan was introduced and the conclusions of the useful points were made. RESULTS AND CONCLUSION: The useful experiences from Japan are of great importance to China's quality consistency evaluation of generic drug.