http://precedings.nature.com/subjects/pharmacology/ Recently posted documents in Pharmacology Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://precedings.nature.com/documents/3883/version/1 Background. Our studies on the role of cholesterol in prion infection/replication showed that brains and peripheral cells of sheep susceptible to or suffering from Scrapie were characterized by an altered cholesterol homeostasis compared to animals with a scrapie-resistant genotype, and that drugs influencing cholesterol esterification were endowed with selective anti-prion activity in N2a cell lines infected with the 22L and RML prion strains. Results. In prion-infected N2a cell lines we now report increased anti-prion activity of dual-drug combinations consisting of cholesterol ester modulators associated with prion inhibitors Synergism was obtained with the cholesterol ester modulators everolimus, pioglitazone, progesterone, and verapamil associated with the anti-prion chlorpromazine, and with everolimus and pioglitazone associated with the anti-prion quinacrine. Comparative lipid analyses in prion-infected and non-infected N2a cells by colorimetric, enzymatic, and chemical means, clearly demonstrated a derangement of type and distribution of cholesterol esters, free cholesterol, and triglycerides in the infected N2a cells. Although single-drug treatments influenced lipid syntheses, only the combined-drug treatments appeared to restore a lipid profile similar to that of untreated-uninfected cells. Conclusions. We conclude that the anti-prion synergistic effect of cholesterol ester modulators with the cholesterol metabolism interfering anti-prion drugs chlorpromazine and quinacrine may arise from the ability of combined drugs to re-establish the intracellular lipid profile of untreated-uninfected cells. Overall, these data suggest that inhibition of prion replication can be readily potentiated by combinatorial drug treatments, and that steps of cholesterol/cholesterol ester metabolism may represent suitable targets. http://precedings.nature.com/documents/3883/version/1 Wed, 21 Oct 2009 15:17:23 UTC In vitro synergistic anti-prion effect of cholesterol ester modulators hdl:10101/npre.2009.3883.1 2009-10-21 Fabrizio Angius Nature Precedings 2009-10-21T15:17:23Z Manuscript Microbiology Neuroscience Pharmacology http://creativecommons.org/licenses/by/3.0/ http://dx.doi.org/10.1038/npre.2009.3882.1 The KOWWIN and ALOGPS octanol-water partition coefficient (Kow) estimation software programs were compared for their capacity to accurately predict log Kow values of 1596 organic compounds on the publicly available Domestic Substances List (DSL) from Environment Canada for which experimental data is available. KOWWIN contained a significantly lower number and magnitude of prediction errors compared to ALOGPS, particularly at experimental log Kow values ow data on the Canadian DSL. Predictive differences of up to 40 log Kow units were found between KOWWIN and ALOGPS, and in some cases, the discrepancies were sufficiently large that strongly opposing hydrophobicity classifications were obtained. http://dx.doi.org/10.1038/npre.2009.3882.1 Wed, 21 Oct 2009 15:02:21 UTC Performance of the ALOGPS 2.1 program for octanol-water partition coefficient prediction with organic chemicals on the Canadian Domestic Substances List doi:10.1038/npre.2009.3882.1 2009-10-21 Sierra Rayne Nature Precedings 2009-10-21T15:02:21Z Manuscript Chemistry Pharmacology Earth & Environment http://creativecommons.org/licenses/by/3.0/ http://dx.doi.org/10.1038/npre.2009.3849.1 A novel microencapsulation technology based on layer-by-layer assembly has been extensively studied and used for controlled delivery of drug microcrystal having poor aqueous solubility and low bioavailability. A non-steroidal anti-inflammatory drug ketoprofen (KF)was selected for encapsulation using biodegradable and biocompatible polyions and synergistically the fabricated system was embedded in gel matrix for topical application. Topical application of the drugs at the pathological sites offer potential advantages of delivering the drug directly to the site of action and thus producing high tissue concentrations of the drug. http://dx.doi.org/10.1038/npre.2009.3849.1 Mon, 12 Oct 2009 17:32:45 UTC Polyelectrolyte multilayer assembly bearing ketoprofen for transdermal delivery doi:10.1038/npre.2009.3849.1 2009-10-12 Rachna Gupta Nature Precedings 2009-10-12T17:32:45Z Poster Pharmacology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3812/version/1 The detection and quantitation of exogenously administered biological macromolecules (e.g. vaccines, peptide and protein therapeutics) and their metabolites is frequently complicated by the presence of a complex endogenous mixture of closely related compounds. We describe a method that incorporates stable isotope labeling of the compound of interest allowing the selective screening of the intact molecule and all metabolites using a modified precursor ion scan. This method involves monitoring the low molecular weight fragment ions produced during MS/MS that distinguish isotopically labelled material from related endogenous compounds. All isotopically labelled substances can be selected using this scanning technique for further analysis whilst other unlabelled and irrelevant substances are ignored. The potential for this technique to be used in metabolism and pharmacokinetic experiments is discussed with specific examples looking at the metabolism of α-synuclein in serum and the brain. http://precedings.nature.com/documents/3812/version/1 Tue, 29 Sep 2009 09:11:02 UTC A novel strategy for the targeted analysis of protein and peptide metabolites hdl:10101/npre.2009.3812.1 2009-09-29 Anthony W. Purcell Nature Precedings 2009-09-29T09:11:02Z Manuscript Biotechnology Immunology Pharmacology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3776/version/1 The emergence of tuberculosis resistant to multiple, first- and second-line antibiotics poses challenges to a global control strategy that relies on standard drug treatment regimens. The high drug-resistant strains of Mycobacterium tuberculosis (Mtb) have been implicated in outbreaks and have been found throughout the world; a comprehensive understanding, the magnitude of this threat requires an accurate assessment of the worldwide burden of resistance. In an attempt to design anti-TB drugs, the target chosen is a key enzyme of Mtb, O-Succinylbenzoate synthase (OSBS), which is an attractive target for its role in electron transport chain as OSBS is not available in humans. An attempt has been to built the 3-D structure of Mtb-OSBS using online Swiss model server. With sequence alignment and scan motif identification, the importance of evolutionarily significant residues that are of functional importance for ligand binding and that form active sites were well established. Molecular simulation calculations of Mtb-OSBS model indicated evolutionarily conserve residues (Lys110 and Lys212) are the best in molecular interaction with substrate 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate (SHCHC). The in silico mutational analysis of Mtb-OSBS model showed the evolutionarily conserved residues that are essential for catalytic activity. It has been found that active site amino acids of Mtb-OSBS are very important to maintain activity of the enzyme, which provides a novel approach to design new pharmacophore SHCHC substrate analogs against Mtb-OSBS. A series of SHCHC substrate analogs (1–100) compounds have been docked with the amino acid residues at the active site of the Mtb-OSBS enzyme, using AutoDock 4.0, a program employed to perform automated molecular docking. The free energies of binding (∆G) and inhibition constants (Ki) of the docked compounds were calculated by the Lamarckian Genetic Algorithm (LGA). Excellent to good correlations between the calculated and experimental Ki values were reported. http://precedings.nature.com/documents/3776/version/1 Fri, 18 Sep 2009 16:35:16 UTC Prediction of Evolutionarily important catalytic amino acid of Mycobacterium tuberculosis O-Succinylbenzoate synthase through in silico mutational analysis hdl:10101/npre.2009.3776.1 2009-09-18 Suresh Kumar Chitta Nature Precedings 2009-09-18T16:35:16Z Poster Biotechnology Microbiology Pharmacology Bioinformatics http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3761/version/1 The escalating number of multidrug resistant pathogens has demanded the swift development of new and potent antibiotics (ref. 2). Metallo-β-lactamases (MBLs) continue to evolve, rendering the latest generation of carbapenem antibiotics useless (ref. 8). SPM-1, a recently discovered MBL, was isolated from a juvenile leukemia patient residing in a hospital in San Palo, Brazil just prior to the patient succumbing to septicemia brought on by Pseudomonas aeruginosa expressing SPM-1 (ref. 8). Screening of the Johns Hopkins Compound library of 1,514 FDA or FAD approved drugs (ref. 1) identified a novel SPM-1 inhibitor that is synergistically compatible with meropenem. Using clinically achievable concentrations, meropenem coupled with nadifloxacin inhibits Pseudomonas aeruginosa expressing SPM-1. This shotgun approach to new drug discovery provided a prompt solution to the grave problem of antibiotic resistant pathogens that are thriving in hospitals today. http://precedings.nature.com/documents/3761/version/1 Tue, 15 Sep 2009 22:47:03 UTC Repurposing of Meropenem and Nadifloxacin for Treatment of Burn Patients? hdl:10101/npre.2009.3761.1 2009-09-15 Jeffrey H. Toney Nature Precedings 2009-09-15T22:47:03Z Manuscript Pharmacology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3738/version/1 Assessing the relative reward value of cocaine and how it changes with repeated use represents a long-standing goal in addiction research. Surprisingly, recent experimental research in rats – the most frequently used animal model in the field – suggests that the reward value of cocaine may in fact be relatively weak at least in the majority of individuals. Here, we provide strong additional evidence that confirms and extends the validity and generality of this research. Specifically, we demonstrate that no matter how heavy is past cocaine self-administration, most rats value cocaine poorly and readily decide to quit when offered the opportunity of making a different choice (i.e., drinking water sweetened with saccharin, an otherwise biologically inessential rewarding behavior). On average, rats estimate that cocaine is worth about 10 times less than the alternative reward. Only a small minority of rats prefer to continue taking cocaine when offered the choice. These findings reveal the existence of a genuine resilience to cocaine addiction in the majority of rats, a phenomenon that has long been suspected, though not firmly demonstrated, in humans. Only a minority would be prone to develop this disorder. We propose that choice should serve as a behavioral screening assay to identify vulnerable individuals, among the resilient majority, in future experimental research on the determinants of cocaine addiction. http://precedings.nature.com/documents/3738/version/1 Wed, 09 Sep 2009 19:01:10 UTC Choice reveals that rats are majoritarily resilient to cocaine addiction hdl:10101/npre.2009.3738.1 2009-09-09 Serge H. Ahmed Nature Precedings 2009-09-09T19:01:10Z Manuscript Neuroscience Pharmacology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3711/version/1 Synthetic oligonucleotides are contaminated with highly homologous failure sequences. Oligonucleotide synthesis is difficult to scale up because it requires expensive equipments, hazardous chemicals, and tedious purification process. Here we report a novel thermocyclic reaction, polymerase-endonuclease amplification reaction (PEAR), for the amplification of oligonucleotides. A target oligonucleotide and a tandem repeated antisense probe are subjected to repeated cycles of denaturing, annealing, elongation and cleaving, in which thermostable DNA polymerase elongation and strand slipping generate duplex tandem repeats, and thermostable endonuclease (PspGI) cleavage releases monomeric duplex oligonucleotides. Each round of PEAR achieves >100-fold amplification. The product can be used in one more round of PEAR directly, and the process can be further repeated. In addition to avoiding dangerous materials and improved product purity, this reaction is easy to scale up and amenable to full automation, so it has the potential to be a useful tool for large-scale production of antisense oligonucleotide drugs. http://precedings.nature.com/documents/3711/version/1 Wed, 02 Sep 2009 13:15:17 UTC Polymerase-endonuclease amplification reaction for large-scale enzymatic production of antisense oligonucleotide hdl:10101/npre.2009.3711.1 2009-09-02 Xiaolong Wang Nature Precedings 2009-09-02T13:15:17Z Manuscript Biotechnology Chemistry Pharmacology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3692/version/1 We report that "preconditioning" of self-assembling nanofibers with embryonic stem cells (ESC) can be used to effectively deliver paracrine/endocrine factors from ESCs to the target tissues. By designing a novel self-assembled peptide nanofiber hydrogel, we examined the regenerative effect of bioactive molecules secreted from ESC in acute kidney injury (AKI). Our findings indicate that preconditioning of nanofibers with ESCs effectively delivers bioactive molecules from ESCs in vitro and in vivo. Our data show that preconditioned nanofibers reverse LPS-induced cell hyperpermeability and apoptosis in vitro. The in vivo data indicate that preconditioned nanofibers significantly improve LPS-induced AKI. Our results also suggest that the Rho kinase inhibition contributes to the renoprotective effect of preconditioned nanofibers. We propose that the use of preconditioned nanofibers is a novel method of stem cell therapy which provides beneficial effects of stem cells, while circumventing many limitations of stem cell therapy, including the issues of cell engraftment, cell viability, immune tolerance, and formation of teratomas. http://precedings.nature.com/documents/3692/version/1 Thu, 27 Aug 2009 12:30:14 UTC Preconditioning of Nanofibers with Embryonic Stem Cells Is Nephroprotective hdl:10101/npre.2009.3692.1 2009-08-27 Farhad Danesh Nature Precedings 2009-08-27T12:30:14Z Manuscript Biotechnology Pharmacology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3688/version/1 The discovery of new anti-influenza drugs is urgent, particularly considering the recent threat of swine flu. In this study, the influenza virus M2 protein was expressed in HEK293 cells and shown to have selective ion channel activity for monovalent ions. The anti-influenza virus drug amantadine hydrochloride significantly attenuated the inward current induced by hyperpolarization of HEK293 cell membranes. Although adamantine derivatives are the only M2 drugs for influenza virus A, their use is limited in the US due to drug resistance. Here we report the discovery of multiple M2 inhibitor lead compounds that were rapidly generated through focused screening of a small primary amine library. The screen was designed using a scaffold-hopping strategy based on amantadine. This study suggests that an antiviral compound directed against a conserved motif may be more useful than amantadine in inhibiting viral replication. http://precedings.nature.com/documents/3688/version/1 Wed, 26 Aug 2009 14:17:18 UTC Discovery of multiple lead compounds as M2 inhibitors through the focused screening of a small primary amine library. hdl:10101/npre.2009.3688.1 2009-08-26 Wenhui Hu Nature Precedings 2009-08-26T14:17:18Z Manuscript Chemistry Pharmacology http://creativecommons.org/licenses/by/3.0/