Publications by authors named "Philippe Labrie"

Biofilm has been implicated in multi-drug resistant organism outbreaks following endoscopic procedures. Automated Endoscope Reprocessors (AER) are devices validated to clean and disinfect endoscopes per applicable standards. The ISO 15883 part 4 standard guides performance testing validation of AERs, including cleaning performance using a biofilm test soil.

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Validating a thermal disinfection process for the processing of medical devices using moist heat via direct temperature monitoring is a conservative approach and has been established as the A0 method. Traditional use of disinfection challenge microorganisms and testing techniques, although widely used and applicable for chemical disinfection studies, do not provide as robust a challenge for testing the efficacy of a thermal disinfection process. Considerable research has been established in the literature to demonstrate the relationship between the thermal resistance of microorganisms to inactivation and the A0 method formula.

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Article Synopsis
  • The study focuses on the importance of reprocessing reusable medical devices to ensure patient safety, examining the efficacy of thermal disinfection standards set by the FDA.
  • It compares the thermal resistance of two Mycobacterium strains, M. hassiacum and M. terrae, to determine which is better suited for validation testing in automated washer-disinfectors.
  • Results show M. terrae is effectively killed at temperatures above 68°C, while M. hassiacum requires temperatures above 75°C, with both strains demonstrating significant log reductions in bacterial counts at specific temperature ranges.
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Experimental research on beetle responses to removal of logging residues following clearcut harvesting in the boreal balsam fir forest of Quebec revealed several abundant rove beetle (Staphylinidae) species potentially important for long-term monitoring. To understand the trophic affiliations of these species in forest ecosystems, it was necessary to analyze their gut contents. We used microscopic and molecular (DNA) methods to identify the gut contents of the following rove beetles: Atheta capsularis Klimaszewski, Atheta klagesi Bernhauer, Oxypoda grandipennis (Casey), Bryophacis smetanai Campbell, Ischnosoma longicorne (Mäklin), Mycetoporus montanus Luze, Tachinus frigidus Erichson, Tachinus fumipennis (Say), Tachinus quebecensis Robert, and Pseudopsis subulata Herman.

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Computational tools such as CoMSIA and CoMFA models reported in a recent study revealed the structure-activity relationships ruling the interactions occurring between hydrophobic N-phenyl-N'-(2-chloroethyl)ureas (CEU) and the colchicine-binding site (C-BS) on beta(II)-tubulin. Here, we describe the mechanisms involved in the covalent binding of three subsets of CEU derivatives to the C-BS. The FlexiDock experiments confirmed that the interaction of non-covalent portions of the CEU auxophore moiety of CEU is involved in the binding of the drug to the C-BS facilitate the nucleophilic attack of Glu-beta198 rather than Cys-beta239.

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To decipher the mechanism underlying the covalent binding of N-phenyl-N'-(2-chloroethyl)ureas (CEU) to the colchicine-binding site on beta(II)-tubulin and to design new and selective antimitotic drugs, we developed 3D quantitative structure-activity relationships (3D-QSAR) models using CoMFA and CoMSIA analyses. The present study correlates the cell growth inhibition activities of 56 structurally related CEU derivatives to several physicochemical parameters representing steric, electrostatic, and hydrophobic fields. Both CoMFA and CoMSIA models using two different optimum numbers of components (ONC) 10 and 4, respectively, gave good internal predictions and their cross-validated r2 values were between 0.

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Synthesis and in vitro cytotoxicity assays of new anthranilamide MDR modulators have been performed to assess their inhibition potency on the P-glycoprotein (P-gp) transporter. Previous studies showed that the replacement of the aromatic spacer group between nitrogen atoms (N(1) and N(2)) in the P-gp inhibitor XR9576 with ethyl or propyl chain is optimal for P-gp inhibition potency. To confirm that observation, the ethyl or the propyl linker arm was replaced with a pyrrolidine or an alicyclic group such as cyclohexyl.

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In a continuing effort to develop potent and selective modulators of P-glycoprotein (P-gp) activity overcoming the chemoresistance acquired by tumor cells during cancer chemotherapy, we developed 3D quantitative structure-activity relationship (3D QSAR) models using CoMFA and CoMSIA analyses. This study correlates the P-glycoprotein inhibitory activities of 49 structurally related anthranilamide derivatives to several physicochemical parameters representing steric, electrostatic, acceptor, donor, and hydrophobic fields. Both CoMFA and CoMSIA models using three different alignment conformations gave good internal predictions, and their cross-validated r2 values are between 0.

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Synthesis and in vitro cytotoxicity assays of new anthranilamide MDR modulators have been performed to assess their inhibition potency of the P-glycoprotein (P-gp) transporter. The aromatic spacer group between nitrogen atoms (N1 and N2) in the known inhibitor XR9576 was replaced with a flexible alkyl chain of 2 to 6 carbon atoms in length. 6,7-Dimethoxy-1,2,3,4-tetrahydroisoquinoline and their open-chain N-methylhomoveratrylamine counterparts were shown to be potent P-gp inhibitors.

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