Search results for "TOXICITY"
showing 10 items of 2261 documents
Mid-infrared supercontinuum generation from 2 to 14 μm in various chalcogenide glasses optical fibers
2019
Chalcogenide glasses optical fibers with step index or microstructured profiles are drawn from low toxicity compositions. Supercontinuum generation lead to an infrared spectrum spanning from 2 to 14µm with a 10µm core fiber of 40mm length.
Cuticular hydrocarbon profiles in Blattella germanica: effects of halofenozide, boric acid and benfuracarb
2006
1379-1176 (Print) Journal Article; In order to complete previous studies conducted on Blattella germanica, three insecticides from different groups were evaluated: boric acid, an inorganic compound, benfuracarb, a carbamate, and halofenozide, a non-steroidal ecdysone agonist. Boric acid (8.20%, LD50) and benfuracarb (2%, LD50) were incorporated into the diet and orally administrated to newly emerged adults of both sexes, while halofenozide (0.33%, LD50) was applied topically. Hydrocarbons extracts was made on bidistilled pentane from control and treated series sampled 6 days following treatment. Extracts was analyzed by gas chromatography. Data showed that cuticular profiles of control and …
285 DOWNREGULATION OF ORGANIC CATION TRANSPORTERS OCT1 (SLC22A1) AND OCT3 (SLC22A3) IN HUMAN HEPATOCELLULAR CARCINOMA AND THEIR PROGNOSTIC SIGNIFICAN…
2012
Background Organic cation transporters (OCT) are responsible for the uptake and intracellular inactivation of a broad spectrum of endogenous substrates and detoxification of xenobiotics and chemotherapeutics. The transporters became pharmaceutically interesting, because OCTs are determinants of the cytotoxicity of platin derivates and the transport activity has been shown to correlate with the sensitivity of tumors towards tyrosine kinase inhibitors. No data exist about the relevance of OCTs in hepatocellular carcinoma (HCC).
A New Benzopyranyl Cadenane Sesquiterpene and Other Antiplasmodial and Cytotoxic Metabolites from Cleistochlamys kirkii
2019
Phytochemical investigations of ethanol root bark and stem bark extracts of Cleistochlamys kirkii (Benth.) Oliv. (Annonaceae) yielded a new benzopyranyl cadinane-type sesquiterpene (cleistonol, 1) alongside 12 known compounds (2&ndash
DNA Binding Studies and Cytotoxicity of a Dinuclear PtII Diazapyrenium- Based Metallo-supramolecular Rectangular Box
2012
The interaction with native DNA of a 2,7-diazapyrenium-based ligand 1 and its Pt II rectangular metal- lacycle 2 is explored through circular and linear dichroism and fluorescence spectroscopies. The metal-free ligand 1 binds through intercalation, with a binding constant of approximately 5 � 10 5 m � 1 , whereas the metallacycle 2 binds and bends the DNA with a bind- ing constant of 7 � 10 6 m � 1 . PCR assays show that metallo-supramolecular box 2 interferes with DNA transactions in vitro whereas the intercalator 1 does not. The metallacycle is active against four human cancer cell lines, with IC50 values ranging between 3.1 and 19.2 mm and shows similar levels of efficacy, but a differen…
cis-Dichloroplatinum(II) complexes tethered to dibenzo[c,h][1,6]naphthyridin-6-ones: Synthesis and cytotoxicity in human cancer cell lines in vitro
2013
A novel family of cisplatin-type complexes tethered to dibenzo[c,h][1,6]naphthyridin-6-one topoisomerase inhibitor via a polymethylene chain and their nonplatinated counterparts were prepared. Their potential cytotoxicity was assessed in three human colorectal cancer cell lines HCT 116, SW480 and HT-29 and compared to the reference molecules cisplatin and oxaliplatin. Platinated compounds were poorly active whilst nonplatinated dibenzo[c,h][1,6]naphthyridin-6-one moieties exhibited higher cytotoxic properties than cisplatin and oxaliplatin whatever the length of the polymethylene chain; molecules containing the tri- and hexamethylene chain length were the most cytotoxic.
Cytotoxic Action of Serratia marcescens Hemolysin on Human Epithelial Cells
1999
ABSTRACT Incubation of human epithelial cells with nanomolar concentrations of chromatographically purified Serratia marcescens hemolysin (ShlA) caused irreversible vacuolation and subsequent lysis of the cells. Vacuolation differed from vacuole formation by Helicobacter pylori VacA. Sublytic doses of ShlA led to a reversible depletion of intracellular ATP. Restoration to the initial ATP level was presumably due to the repair of the toxin damage and was inhibited by cycloheximide. Pores formed in epithelial cells and fibroblasts without disruption of the plasma membrane, and the pores appeared to be considerably smaller than those observed in artificial lipid membranes and in erythrocytes a…
Insight into the primary mode of action of TiO2 nanoparticles on Escherichia coli in the dark.
2015
16 pages; International audience; Large-scale production and incorporation of titanium dioxide nanoparticles (NP-TiO2 ) in consumer products leads to their potential release into the environment and raises the question of their toxicity. The bactericidal mechanism of NP-TiO2 under UV light is known to involve oxidative stress due to the generation of reactive oxygen species. In the dark, several studies revealed that NP-TiO2 can exert toxicological effects. However, the mode of action of these nanoparticles is still controversial. In the present study, we used a combination of fluorescent probes to show that NP-TiO2 causes Escherichia coli membrane depolarization and loss of integrity, lead…
Dynamic regulation of CD8 T cell tolerance induction by liver sinusoidal endothelial cells.
2010
Abstract Cross-presentation of soluble Ag on MHC class I molecules to naive CD8 T cells by liver sinusoidal endothelial cells (LSECs) leads to induction of T cell tolerance that requires interaction between coinhibitory B7-H1 on LSECs and programmed cell death-1 on CD8 T cells. In this study, we investigate whether cross-presentation of high as well as low Ag concentrations allowed for LSEC-induced tolerance. Ag concentration directly correlated with the cross-presentation capacity of murine LSECs and thus strength of TCR stimulation. Although LSEC cross-presentation at low-Ag concentrations resulted in tolerance, they induced differentiation into effector T cells (CTL) at high-Ag concentra…
Comparative diazinon toxicity in guppy and zebra fish: Different role of oxidative metabolism
1993
Guppies pretreated with 1.1 μmol/L diazinon (0.5 times the LC50 with the guppy) for 7 d were less susceptible to the toxicity of the compound. The LC50 in these fish was about five times higher than that in nonpretreated animals. The lethal body burden and the slope of the concentration-response curve of diazinon in pretreated guppies were similar to those in zebra fish. The 7-d pretreatment of zebra fish with 12 μmol/L diazinon (0.5 times the LC50 with the zebra fish) did not affect the susceptibility of this species to diazinon. The pretreatment of guppies resulted in a strong inhibition of the formation of diazoxon and pyrimidinol during incubations of diazinon with the hepatic postmitoc…