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Trypanocidal Activity of Melamine-Based Nitroheterocycles. Mhairi L. Stewart, 2004.A series of nitroheterocyclic compounds were designed with linkages to melamine or benzamidine groups that are known substrates of the P2 aminopurine and other transporters in African trypanosomes of the brucei group . Several compounds showed in vitro trypanotoxicity with 50% inhibitory concentrations in the submicromolar range . Although most compounds interacted with the P2 transporter, as judged by their ability to inhibit adenosine transport via this carrier, uptake through this route was not necessary for activity since TbAT1-null mutant parasites, deficient in this transporter, retained sensitivity to these drugs . One compound, a melamine-linked nitrofuran, also showed pronounced activity against parasites in mice . Studies into the mode of action of this compound indicated that neither reductive, nor oxidative, stress were related to its trypanocidal activity ruling out a genotoxic effect in T . brucei, distinguishing it from some other, mammalian cell toxic, trypanocidal nitroheterocycles . Intestinal Mucus Alters the Ability of Probiotic Bacteria To Bind Aflatoxin B1 In Vitro. S. Gratz, 2004. Mechanism of Coupling of Transport to Hydrolysis in Bacterial ATP-Binding Cassette Transporters. Amy L. Davidson, 2002. Chlorine Inactivation of Adenovirus Type 40 and Feline Calicivirus. Jeanette A. Thurston-Enriquez, 2003.Ct values, the concentration of free chlorine multiplied by time of contact with virus, were determined for free-chlorine inactivation experiments carried out with chloroform-extracted (dispersed) and non-chloroform-extracted (aggregated) feline calicivirus (FCV), adenovirus type 40 (AD40), and polio virus type 1 (PV-1) . Experiments were carried out with high and low pH and temperature conditions . Ct values were calculated directly from bench-scale free-chlorine inactivation experiments and from application of the efficiency factor Hom model . For each experimental condition, Ct values were higher at pH 8 than at pH 6, higher at 5°C than at 15°C, and higher for dispersed AD40 (dAD40) than for dispersed FCV (dFCV) . dFCV and dAD40 were more sensitive to free chlorine than dispersed PV-1 (dPV-1) . Cts for 2 log inactivation of aggregated FCV (aFCV) and aggregated PV-1 (aPV-1) were 31.0 and 2.8 orders of magnitude higher than those calculated from experiments carried out with dispersed virus . Cts for 2 log inactivation of dFCV and dAD40 in treated groundwater at 15°C were 1.2 and 13.7 times greater than in buffered-demand-free (BDF) water experiments at 5°C . Ct values listed in the U.S . Environmental Protection Agency (EPA) Guidance Manual were close to, or lower than, Ct values generated for experiments conducted with dispersed and aggregated viruses suspended in BDF water and for dispersed viruses suspended in treated groundwater . Since the state of viruses in water is most likely to be aggregated and associated with organic or inorganic matter, reevaluation of the EPA Guidance Manual Ct values is necessary, since they would not be useful for ensuring inactivation of viruses in these states . Under the tested conditions, dAD40, dFCV, aFCV, dPV-1, and aPV-1 particles would be inactivated by commonly used free chlorine concentrations (1 mg/liter) and contact times (60 to 237 min) applied for drinking water treatment in the United States .
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