Lysis of human monocytic leukemia cells by extracellular adenosine triphosphate: mechanism and characterization of the adenosine triphosphate receptor

The present study shows that extracellular adenosine triphosphate (ATP) has the capacity to mediate dose-dependent lysis of the monocytic leukemia cell line THP-1. The lysis, assessed by 51Cr release, was found to be selective for ATP, because adenosine diphosphate (ADP) or other nucleotides were less effective in their ability to lyse the cells. The amount of 51Cr released was particularly enhanced by the stimulation of the cells with 1,000 U/mL of interferon gamma (IFN-gamma) for 3 days, and the sensitivity was time and dose dependent. Analysis of the mechanism of lysis indicated that the fully ionized form, ATP4-, mediated the lysis, because the addition of cation chelators or the absence of the divalent cations, Ca2+ and Mg2+, in the culture medium of a 6-hour 51Cr release assay increased the percent specific lysis. Therefore, the ATP receptors on THP-1 cells were classified as P2Z purinoceptors. Moreover, it is shown here that the Ca2+/calmodulin complex plays a role in the regulation of the lysis by extracellular ATP of THP-1 cells, because antagonists of this complex, such as trifluoperazine or KN-62, were found to inhibit the ATP-mediated cell lysis.     

The uptake of fenbendazole by cattle and buffalo following long-term low-level administration in urea-molasses blocks: further studies on block formulations

Fenbendazole (Hoechst India Ltd.) was incorporated at 0.5 g/kg into urea molasses blocks made by two different processes. The proportion of the drug remaining in the blocks and the plasma concentrations of the parent compound and its metabolites were measured. Recovery of the drug in blocks made by the cold and the modified hot processes was 90% and 96%, respectively. The plasma metabolite profile revealed a plateau between days 4 and 6 of feeding in cattle and buffalo. However, the plasma concentrations of fenbendazole and its metabolites were low in buffalo compared to cattle.     

Electrical properties of N2O/NH3 plasma grownoxynitride on strained-Si

Growth of ultrathin (<100 Å) oxynitride on strained-Si using microwave N₂O and NH₃ plasma is reported. X-ray photoelectron spectroscopy (XPS) results indicate a nitrogen-rich layer at the strained-Si/SiO₂ interface. The electrical properties of oxynitrides have been characterized using a metal-insulator-semiconductor (MIS) structure. A moderately low value of insulator charge density (6.1×10¹⁰ cm^-2) has been obtained for NH₃ plasma treated N₂O oxide sample. Nitrided oxide shows a larger breakdown voltage and an improved charge trapping properties under Fowler-Nordheim (F-N) constant current stress     

Synthetic resins: XV. Chelation ion exchange properties of 2,4- dinitrophenylhydrazone of resacetophenone-formaldehyde resin

A number of copolymers were synthesised by condensing the 2,4-dinitrophenylhydrazone of resacetophenone with substituted benzoic acids/ phenols and formaldehyde in the presence of sodium hydroxide or hydrochloric acid. The decomposition temperature, solubility and viscosity of the polymers have been determined. The ion-exchange properties have been studied by using a batch equilibrium method. The distribution of a number of metal ions between an aqueous solution and the resin have been measured. A wide range of pH and variable ionic strengths have been investigated.