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Fiore MC, Keller PA, Curry SJ. Health system changes to facilitate the delivery of tobacco-dependence treatment. Am J Prev Med 2007; 33:S349-56. [PMID: 18021910 DOI: 10.1016/j.amepre.2007.09.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 08/02/2007] [Accepted: 09/10/2007] [Indexed: 11/26/2022]
Abstract
In 1996, the Agency for Health Care Policy and Research (AHCPR, now AHRQ, the Agency for Healthcare Research and Quality) released the first federal clinical practice guideline for smoking cessation that was updated in 2000 by the United States Public Health Service (USPHS). The innovative guideline identified six evidence-based strategies for healthcare systems to facilitate the institutionalization of tobacco dependence treatment so that smokers received evidence-based treatments as a routine part of health care. A growing body of evidence demonstrates the importance of systems approaches. This paper discusses the evidence for the systems-level strategies outlined in the guidelines, as well as future directions and needed systems-level research. Promising strategies include: (1) clinical systems organized to cue assessment of smoking status and assistance to smokers, (2) leveraging clinical information systems to provide performance feedback, (3) providing full insurance coverage for evidence-based cessation treatment, and (4) including tobacco-cessation treatment as a measured standard of care by national accreditation organizations. These systems-level approaches increase the likelihood that tobacco use is addressed systematically in the healthcare delivery system. Further research to optimize the effectiveness and adoption of these strategies will help ensure that patients receive evidence-based interventions that foster tobacco-use cessation.
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Keller PA, Koss KJ, Baker TB, Bailey LA, Fiore MC. Do state characteristics matter? State level factors related to tobacco cessation quitlines. Tob Control 2007; 16 Suppl 1:i75-80. [PMID: 18048637 PMCID: PMC2598526 DOI: 10.1136/tc.2006.019745] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Accepted: 04/18/2007] [Indexed: 11/04/2022]
Abstract
BACKGROUND Quitline services are an effective population-wide tobacco cessation strategy adopted widely in the United States as part of state comprehensive tobacco control efforts. Despite widespread evidence supporting quitlines' effectiveness, many states lack sufficient financial resources to adequately fund and promote this service. Efforts to augment state tobacco control efforts might be fostered by greater knowledge of state level factors associated with the funding and implementation of those efforts. METHODS We analysed data from the 2004 North American Quitline Consortium survey and from publicly available sources to identify state level factors related to quitline implementation and funding. Factors included in the analyses were state demographic characteristics, tobacco use variables, state tobacco control spending, and economic and political climate variables. Univariate and multivariate regression analyses were conducted. RESULTS The best fitting multivariate model that significantly predicted the presence or absence of a state quitline included only cigarette excise tax rate (p = 0.020). In terms of funding levels, states with high rates of cigarette consumption (p = 0.047) and with higher per capita expenditures for tobacco control programmes (p = 0 .0.004) were most likely to spend more on per capita operations budget for quitlines. CONCLUSION State level factors appear to play a part in whether states had established quitlines by mid-2004 and the amount of per capita quitline funding.
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Abstract
Corticotrophin Releasing Hormone (CRH) is a primary hormone in the fight or flight response targeting a membrane bound G-protein coupled receptor (GPCR). Many people worldwide stand to benefit by the development of CRH agonists and antagonists for the treatment of anxiety and depression, with additional therapeutic targets including Alzheimer's, pain and the prevention of premature birth: so why the delay in development? In this review, we will discuss not only CRH, related proteins, receptors and ligands, but some of the obstacles that have arisen, as well as strategies being pursued to overcome these problems in the pursuit of this GPCR targeted therapeutic. Several key proteins influence the complex and intrinsic regulation of CRH, including its receptors (CRHR), of which 3 types have been categorised, CRHR(1), CRHR(2), CRHR(3), each containing active and inactive splice variants. Additionally, the CRH binding protein (CRHBP) is believed to moderate the effects of CRH at the receptor, whether it is as a molecular mop, or a delivery vessel, or both, is still being investigated. Homology based receptor modelling is a technique that has only recently become available with the crystallisation of bovine rhodopsin (a GPCR), [1] and the application of this technique to the CRH receptors is still in the early stages of development. Therefore, the medicinal chemist has previously had to rely on ligand-based strategies, specifically, the development of pharmacophores. Thus, an extensive number of both CRH peptide analogues and small ligands that show nanomolar antagonism have been developed with SAR libraries being integral to the iterative drug design process.
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Gordon CP, Griffith R, Keller PA. Control of HIV Through the Inhibition of HIV-1 Integrase: A Medicinal Chemistry Perspective. Med Chem 2007; 3:199-220. [PMID: 17348857 DOI: 10.2174/157340607780059558] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This article reviews the current status of classes of HIV-1 integrase enzyme inhibitors. These classes include peptide-based inhibitors, natural products, polyhydroxylated aromatics, diketo acids, naphthyridines, and sulfonated compounds including sulfonic acids. Discussions of structure activity relationships are presented and include the current overview of the structure-based model, suitable for the further design and development. To date, the advances in the medicinal chemistry of HIV-1 integrase inhibitors have relied mostly on ligand-based designs leading to most displaying similar binding interactions within the active site or at the dimer interface. This paves the way for single enzyme mutations rendering entire compound classes inactive and thus, the requirement for second and third generation inhibitors with novel modes of binding is apparent. To facilitate future structure-based drug design efforts, a model of the biologically relevant structure of the HIV-1 integrase enzyme, a dimer of dimers has also been discussed.
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Keller PA, Bailey LA, Koss KJ, Baker TB, Fiore MC. Organization, financing, promotion, and cost of U.S. quitlines, 2004. Am J Prev Med 2007; 32:32-7. [PMID: 17184958 DOI: 10.1016/j.amepre.2006.08.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Revised: 08/03/2006] [Accepted: 08/30/2006] [Indexed: 11/27/2022]
Abstract
BACKGROUND Quitlines have been established as an effective, evidence-based, population-wide strategy to deliver smoking-cessation treatment, and are now available in most states across America. However, little is known about the organization, financing, promotion, and cost of state quitlines. METHODS In 2004, the North American Quitline Consortium surveyed the 50 states and Washington DC to obtain information about state quitlines. Data were analyzed in fall 2005 through spring 2006. Analyses of these data are reported in this paper. RESULTS Analyses were limited to the 38 states that reported having a quitline in 2004. State governments funded most (89.5%) quitlines. Median state quitline operating budgets in 2004 were 500,000 dollars; this translates into a modest annual median operating cost of 0.14 dollar per capita or 0.85 dollar per adult smoker. A lesser amount was spent for quitline promotion. Quitline services varied, with 97.4% of respondents providing mailed self-help resources, 89.5% providing proactive telephone counseling, and 89.2% providing referrals to other services. Many quitlines provide services in languages other than English. Only 21.1% of quitlines reported providing cessation medication at no cost. Promotional strategies varied widely. CONCLUSION A large majority of U.S. smokers live in states with tobacco quitlines, which provide cessation treatment at a remarkably modest per capita cost. There is a great deal of congruence in services and promotional strategies among states. Further research is required to determine how external factors such as the federal National Network of Tobacco Cessation Quitlines funding for state quitlines and the availability of a national portal number (1-800-QUITNOW), both implemented in 2004, affect state quitlines. Additional research to evaluate the cost effectiveness of quitline services is also warranted.
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Produit-Zengaffinen N, Davis-Lameloise N, Perreten H, Bécard D, Gjinovci A, Keller PA, Wollheim CB, Herrera P, Muzzin P, Assimacopoulos-Jeannet F. Increasing uncoupling protein-2 in pancreatic beta cells does not alter glucose-induced insulin secretion but decreases production of reactive oxygen species. Diabetologia 2007; 50:84-93. [PMID: 17131143 DOI: 10.1007/s00125-006-0499-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Accepted: 09/04/2006] [Indexed: 01/05/2023]
Abstract
AIMS/HYPOTHESIS Levels of uncoupling protein-2 (UCP2) are regulated in the pancreatic beta cells and an increase in the protein level has been associated with mitochondrial uncoupling and alteration in glucose-stimulated insulin secretion. However, it is not clear whether an increase in uncoupling protein-2 per se induces mitochondrial uncoupling and affects ATP generation and insulin secretion. MATERIALS AND METHODS Transgenic mice with beta cell-specific overexpression of the human UCP2 gene and INS-1 cells with doxycycline-inducible overproduction of the protein were generated and the consequences of increased levels of UCP2 on glucose-induced insulin secretion and on parameters reflecting mitochondrial uncoupling were determined. RESULTS In transgenic mice, an increase in beta cell UCP2 protein concentration did not significantly modify plasma glucose and insulin levels. Glucose-induced insulin secretion and elevation in the ATP/ADP ratio were unaltered by an increase in UCP2 level. In INS-1 cells, a similar increase in UCP2 level did not modify glucose-induced insulin secretion, cytosolic ATP and ATP/ADP ratio, or glucose oxidation. Increased levels of UCP2 did not modify the mitochondrial membrane potential and oxygen consumption. Increased UCP2 levels decreased cytokine-induced production of reactive oxygen species. CONCLUSION/INTERPRETATION The results obtained in transgenic mice and in the beta cell line do not support the hypothesis that an increase in UCP2 protein per se uncouples the mitochondria and decreases glucose-induced insulin secretion. In contrast, the observation that increased UCP2 levels decrease cytokine-induced production of reactive oxygen species indicates a potential protective effect of the protein on beta cells, as observed in other cell types.
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Perry RJ, Keller PA, Fraser D, Fiore MC. Fax to quit: a model for delivery of tobacco cessation services to Wisconsin residents. WMJ : OFFICIAL PUBLICATION OF THE STATE MEDICAL SOCIETY OF WISCONSIN 2005; 104:37-40, 44. [PMID: 16117232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Research has shown that proactive tobacco cessation quitlines are effective in increasing quit rates 4-fold, compared to quitting with no counseling support. In Wisconsin, the state-funded Wisconsin Tobacco Quit Line has documented a quit rate of 22%, with an estimated 6700 individuals quitting as a result of receiving Quit Line services. Since its launch in 2001, the Wisconsin Tobacco Quit Line has assisted more than 36,000 callers. Until recently, quitline call volume has been highly dependent on paid media campaigns-an expensive, episodic, and often politically difficult strategy to fund at the state level. To foster and sustain quitline use and assist health care professionals in helping their patients successfully quit, the University of Wisconsin Center for Tobacco Research and Intervention (UW-CTRI) developed the "Fax to Quit" program in March 2003. The model involves close collaboration between UW-CTRI and health care delivery systems who train their staff and integrate a quitline referral system into their regular delivery of health care for smokers who are interested in having the quitline contact them. This paper examines the extent to which this approach has been adopted by health care providers in Wisconsin. The potential is for this to become a key component of an integrated tobacco dependence treatment.
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Keller PA, Fiore MC, Curry SJ, Orleans CT. Systems change to improve health and health care: Lessons from Addressing Tobacco in Managed Care. Nicotine Tob Res 2005; 7 Suppl 1:S5-8. [PMID: 16036270 DOI: 10.1080/14622200500077966] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Fiore MC, Croyle RT, Curry SJ, Cutler CM, Davis RM, Gordon C, Healton C, Koh HK, Orleans CT, Richling D, Satcher D, Seffrin J, Williams C, Williams LN, Keller PA, Baker TB. Preventing 3 million premature deaths and helping 5 million smokers quit: a national action plan for tobacco cessation. Am J Public Health 2004; 94:205-10. [PMID: 14759928 PMCID: PMC1448229 DOI: 10.2105/ajph.94.2.205] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2003] [Indexed: 11/04/2022]
Abstract
In August 2002, the Subcommittee on Cessation of the Interagency Committee on Smoking and Health (ICSH) was charged with developing recommendations to substantially increase rates of tobacco cessation in the United States. The subcommittee's report, A National Action Plan for Tobacco Cessation, outlines 10 recommendations for reducing premature morbidity and mortality by helping millions of Americans stop using tobacco. The plan includes both evidence-based, population-wide strategies designed to promote cessation (e.g., a national quitline network) and a Smokers' Health Fund to finance the programs (through a 2 US dollar per pack excise tax increase). The subcommittee report was presented to the ICSH (February 11, 2003), which unanimously endorsed sending it to Secretary Thompson for his consideration. In this article, we summarize the national action plan.
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Golovin A, Oldfield TJ, Tate JG, Velankar S, Barton GJ, Boutselakis H, Dimitropoulos D, Fillon J, Hussain A, Ionides JMC, John M, Keller PA, Krissinel E, McNeil P, Naim A, Newman R, Pajon A, Pineda J, Rachedi A, Copeland J, Sitnov A, Sobhany S, Suarez-Uruena A, Swaminathan GJ, Tagari M, Tromm S, Vranken W, Henrick K. E-MSD: an integrated data resource for bioinformatics. Nucleic Acids Res 2004; 32:D211-6. [PMID: 14681397 PMCID: PMC308812 DOI: 10.1093/nar/gkh078] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The Macromolecular Structure Database (MSD) group (http://www.ebi.ac.uk/msd/) continues to enhance the quality and consistency of macromolecular structure data in the Protein Data Bank (PDB) and to work towards the integration of various bioinformatics data resources. We have implemented a simple form-based interface that allows users to query the MSD directly. The MSD 'atlas pages' show all of the information in the MSD for a particular PDB entry. The group has designed new search interfaces aimed at specific areas of interest, such as the environment of ligands and the secondary structures of proteins. We have also implemented a novel search interface that begins to integrate separate MSD search services in a single graphical tool. We have worked closely with collaborators to build a new visualization tool that can present both structure and sequence data in a unified interface, and this data viewer is now used throughout the MSD services for the visualization and presentation of search results. Examples showcasing the functionality and power of these tools are available from tutorial webpages (http://www. ebi.ac.uk/msd-srv/docs/roadshow_tutorial/).
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Keller PA, Kirkwood K, Morgan J, Westcott S, McCluskey A. The prevention of preterm labour -- corticotropin releasing hormone type 1 receptors as a target for drug design and development. Mini Rev Med Chem 2003; 3:295-303. [PMID: 12678823 DOI: 10.2174/1389557033488105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of the corticotropin releasing hormone in the onset of labour and the subsequent medicinal chemistry implications of CRH antagonists for the prevention of premature birth, and identification of the CRH type 1 receptor as the target for this drug design, are reviewed here.
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Boutselakis H, Dimitropoulos D, Fillon J, Golovin A, Henrick K, Hussain A, Ionides J, John M, Keller PA, Krissinel E, McNeil P, Naim A, Newman R, Oldfield T, Pineda J, Rachedi A, Copeland J, Sitnov A, Sobhany S, Suarez-Uruena A, Swaminathan J, Tagari M, Tate J, Tromm S, Velankar S, Vranken W. E-MSD: the European Bioinformatics Institute Macromolecular Structure Database. Nucleic Acids Res 2003; 31:458-62. [PMID: 12520052 PMCID: PMC165512 DOI: 10.1093/nar/gkg065] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2002] [Accepted: 10/03/2002] [Indexed: 11/14/2022] Open
Abstract
The E-MSD macromolecular structure relational database (http://www.ebi.ac.uk/msd) is designed to be a single access point for protein and nucleic acid structures and related information. The database is derived from Protein Data Bank (PDB) entries. Relational database technologies are used in a comprehensive cleaning procedure to ensure data uniformity across the whole archive. The search database contains an extensive set of derived properties, goodness-of-fit indicators, and links to other EBI databases including InterPro, GO, and SWISS-PROT, together with links to SCOP, CATH, PFAM and PROSITE. A generic search interface is available, coupled with a fast secondary structure domain search tool.
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Keller PA, Murray JD, Hargrove DS. A rural mental health research agenda: defining context and setting priorities. J Rural Health 2002; 15:316-25. [PMID: 11942564 DOI: 10.1111/j.1748-0361.1999.tb00753.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This article provides a brief overview of research perspectives on rural mental health services and suggests the importance of building an agenda to bring coherence to studies in this area. The need for sound theory and methodology to guide research is emphasized. The importance of better conceptualization of the rural context as a focus of research is addressed, and 14 propositions concerning issues the authors think will advance rural research are presented. This article is intended to stimulate discussion about a research agenda that will lead to better understanding of rural needs for mental health services as well as more responsive service models.
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Madden JA, Keller PA, Kleinman JG. Changes in smooth muscle cell pH during hypoxic pulmonary vasoconstriction: a possible role for ion transporters. Physiol Res 2001; 49:561-6. [PMID: 11191360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) occurs in smooth muscle cells (SMC) from small pulmonary arteries (SPA) and is accompanied by increases in free cytoplasmic calcium ([Ca2+]i) and cytoplasmic pH (pHi). SMC from large pulmonary arteries (LPA) relax during hypoxia, and [Ca2+]i and pHi decrease. Increases in pHi and [Ca2+]i in cat SPA SMC during hypoxia and the augmentation of hypoxic pulmonary vasoconstriction by alkalosis seen in isolated arteries and lungs suggest that cellular mechanisms, which regulate inward and outward movement of Ca2+ and H+, may participate in the generation of HPV. SMC transport systems that regulate pHi include the Na+ - H+ transporter which regulates intracellular Na+ and H+ and aids in recovery from acid loads, and the Na+ -dependent and Na+ -independent Cl-/HCO3- transporters which regulate intracellular chloride. The Na+ -dependent Cl-/HCO3- transporter also aids in recovery from acidosis in the presence of CO2 and HCO3-. The Na+ -independent Cl-/HCO3- transporter aids in recovery from cellular alkalosis. The Na+ - H+ transporter was present in SMC from SPA and LPA of the cat, but it seemed to have little if any role in regulating pHi in the presence of CO2 and HCO3-. Inhibiting the Cl-/HCO3- transporters reversed the normal direction of pHi change during hypoxia, suggesting a role for these transporters in the hypoxic response. Future studies to determine the interaction between pHi, [Ca2+]i and HPV should ascertain whether pHi and [Ca2+]i changes are linked and how they may interact to promote or inhibit SMC contraction.
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Keller PA. Comparison of two inversion techniques of a semi-analytical model for the determination of lake water constituents using imaging spectrometry data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2001; 268:189-196. [PMID: 11315740 DOI: 10.1016/s0048-9697(00)00690-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In this study, two different inversion techniques for the determination of chlorophyll-a in water were compared by a sensitivity analysis: (i) a matrix inversion method, and (ii) a curve-fitting routine. Adding white noise to the reflectance spectrum led to clearly better results for the curve-fitting routine. If, however, the atmospheric parameter visibility was not exactly known, both methods behaved similarly well. The analyses implied that the performance depended on the quality of the input spectra, the knowledge of model parameters, and also on the inversion methods, even if they were based on the same semi-analytical model. Of course, not only the uncertainties of model parameters had to be considered for the testing of the performance, but also other factors, such as processing time, implementation of the inversion algorithm, number of relevant parameters, and the application of the method to different times and different lakes.
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Madden JA, Ray DE, Keller PA, Kleinman JG. Ion exchange activity in pulmonary artery smooth muscle cells: the response to hypoxia. Am J Physiol Lung Cell Mol Physiol 2001; 280:L264-71. [PMID: 11159005 DOI: 10.1152/ajplung.2001.280.2.l264] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purposes of this study were to determine 1) the presence of the major ion transport activities that regulate cytoplasmic pH (pH(c)) in cat pulmonary artery smooth muscle cells, i.e., Na+/H+ and the Na+-dependent and -independent Cl-/HCO3- exchange, 2) whether pH(c) changes in cells from small (SPAs) and large (LPAs) pulmonary arteries during hypoxia, and 3) whether changes in pH(c) are due to changes in the balance of exchange activities. Exchange activities as defined by physiological maneuvers rather than molecular identity were ascertained with fluorescence microscopy to document changes in the ratio of the pH(c) indicator 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein. Steady-state pH(c) was higher in LPA than in SPA normoxic smooth muscle cells. SPAs and LPAs possessed all three transport activities; in HCO3- containing normoxic solutions, Cl-/HCO3- exchange rather than Na+/H+ exchange set the level of pH(c); in HCO3- containing hypoxic solutions, pH(c) increased in SPA and decreased in LPA cells; altering the baseline pH(c) of a cell type to that of the other did not change the direction of the pH(c) response during hypoxia. The absence of Na+ prevented hypoxia-induced alkalinization in SPA cells; in both cell types, inhibiting the Cl-/HCO3- exchange activities reversed the normal direction of pH(c) changes during hypoxia.
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Keller PA, Elfick L, Garner J, Morgan J, McCluskey A. Corticotropin releasing hormone: therapeutic implications and medicinal chemistry developments. Bioorg Med Chem 2000; 8:1213-23. [PMID: 10896102 DOI: 10.1016/s0968-0896(00)00074-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Corticotropin releasing hormone (CRH, sometimes known as CRF) is an endogenous 41 amino acid peptide that has been implicated in the onset of pregnancy, the 'fight or flight' response, in addition to a large number of physiological disorders. Recently, medicinal chemists have developed a number of potent and selective compounds that show promise in a vast array of therapeutic uses. Herein we review the current status of research.
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Keller PA, Leach SP, Luu TT, Titmuss SJ, Griffith R. Development of computational and graphical tools for analysis of movement and flexibility in large molecules. J Mol Graph Model 2000; 18:235-41, 299. [PMID: 11021539 DOI: 10.1016/s1093-3263(00)00028-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We developed a computer program for the calculation and display of the difference distance matrices (DDMs) of macromolecules that has the ability to compare multiple structures simultaneously. To demonstrate its use, a data set of atoms for superimposition of the HIV-1 reverse transcriptase enzyme was defined using the coordinates for the 21 available crystal structures of this enzyme and its complexes. The DDM technique for superimposition data set generation allows selection of atoms that are invariant in all structures, is free from user bias, and represents the most accurate and precise method of producing such subsets. Comparison of this technique was made against other published methods of generating superimposition data sets, and it was found that significant differences in magnitude and trends of atom movements are observed depending on which data set was used.
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Keller PA, Bowman M, Dang KH, Garner J, Leach SP, Smith R, McCluskey A. Pharmacophore development for corticotropin-releasing hormone: new insights into inhibitor activity. J Med Chem 1999; 42:2351-7. [PMID: 10395475 DOI: 10.1021/jm9900117] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Corticotropin-releasing hormone (CRH) is an endogenous 41-amino acid peptide involved in a wide ranging series of systems including the brain, the coordination of the body's overall response to stress, and more recently as a crucial initiator in the onset of labor, also known as the placental clock. Although more physiological data on CRH is emerging shedding more light on the processes involved and their integration, the mode of action of the hormone and the postulated binding site(s) remain unknown. Recently, a number of small-molecular-weight ligands have emerged as potent antagonists but, as therapeutics, suffer from a lack of solubility. Additionally, despite a number of exhaustively large patents, the lack of structural diversity with these antagonists has enabled little scope for comprehensive and wide ranging studies into the structure of the binding sites of this hormone. As part of a program investigating new, structurally diverse antagonists and agonists of CRH, we have developed a preliminary pharmacophore based on the known small-molecular-weight ligands as an initial step in our program. This pharmacophore was validated by comparison with some of the compounds we postulated to be active.
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Keller PA. Converting the unconverted: the effect of inclination and opportunity to discount health-related fear appeals. JOURNAL OF APPLIED PSYCHOLOGY 1999; 84:403-15. [PMID: 10380420 DOI: 10.1037/0021-9010.84.3.403] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Two experiments indicated that the conventional wisdom for designing fear appeals, higher fear arousal, and a consequences-recommendations ordering, was more persuasive for adherents, or those who were already following the advocated recommendations. Instead, lowering the level of fear arousal and reversing the order of the consequences and recommendations were more effective for persuading the unconverted. The unconverted were more persuaded by the latter message format because it reduced the level of message discounting. Specifically, unconverted participants who received either a low fear appeal or recommendations preceding consequences perceived themselves to be more susceptible, perceived the consequences as more severe, regarded the recommendations as more efficacious, believed they were more able to follow the recommendations, and were less likely to refute the message claims.
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Titmuss SJ, Keller PA, Griffith R. Docking experiments in the flexible non-nucleoside inhibitor binding pocket of HIV-1 reverse transcriptase. Bioorg Med Chem 1999; 7:1163-70. [PMID: 10428388 DOI: 10.1016/s0968-0896(99)00012-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Docking experiments were undertaken using a number of published crystal structures of HIV-1 reverse transcriptase complexes with various non-nucleoside inhibitors. The docking method was validated by successfully docking each ligand, in the conformation found in the crystal structure of the complex with the enzyme, back into its binding pocket in the right orientation and position. Each ligand was then subjected to conformational searching and a database of unique low-energy conformations of all ligands established. Docking this database into each of the reverse transcriptase binding pockets showed that all inhibitors could be fitted into each different pocket, without alteration of the pocket geometry. This contradicts findings from earlier docking investigations and implies that the conformation of the binding pocket in each different complex is conserved sufficiently to allow particular uniform ligand binding modes. The inhibitor conformations selected by this docking process are mostly the same as the one the ligand adopts in its own pocket and the selected conformations and orientations exhibit an impressive degree of similarity in the arrangement of their steric and electronic features. A correlation has also been observed between inhibitor flexibility and tightness of fit into the pockets with the more flexible inhibitors achieving a tighter fit and thus fewer favourable orientations upon docking.
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Keller PA, Henrick K, McNeil P, Moodie S, Barton GJ. Deposition of macromolecular structures. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 1998; 54:1105-8. [PMID: 10089486 DOI: 10.1107/s0907444998008464] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Macromolecular structures are being determined at an increasing rate, and are of interest to a wide diversity of researchers. Depositing a macromolecular structure with the Protein Data Bank makes it readily available to the community. Accuracy, consistency and machine-readability of the data are essential, as are clear indications of quality, and sufficient information to allow non-experimentalists to interpret the data. Good-quality depositions are necessary to allow this to be achieved. The PDB's AutoDep system allows deposition and some preliminary automatic checking to take place at multiple sites, prior to full processing and release of the structure by the PDB. However, depositing a structure currently requires the manual entry of a large amount of information at the time of deposition. The data-harvesting approach will allow much more information to be deposited, without placing an additional burden on the depositor. Deposition-ready files will be generated automatically during the course of a structure-determination experiment. The additional information will allow improved validation procedures to be applied to the structures, and the data to be made more useful to the wider scientific community.
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Madden JA, al-Tinawi A, Birks E, Keller PA, Dawson CA. Intrinsic tone and distensibility of in vitro and in situ cat pulmonary arteries. Lung 1996; 174:291-301. [PMID: 8843055 DOI: 10.1007/bf00176188] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This study was designed to determine the in vitro and in situ diameter vs pressure relationship of 200- to 1,200-microns diameter pulmonary arteries in the cat. Diameter vs pressure relationships of these arteries were obtained using two methods, microscopic observation of in vitro cannulated and pressurized arteries and X-ray angiography of in situ arteries. Both in vitro and in situ arteries were studied first under normal conditions and then after reducing tone with Ca(2+)-free solution (in vitro) or papaverine (in situ). In vitro arteries commonly increased their tone in response to elevated transmural pressure, and in some cases, the diameter actually decreased as pressure increased. This behavior was not observed in the in situ arteries. The major difference between in vitro and in situ arteries was that when the in vitro arteries were relaxed, the slope of the diameter vs pressure curves increased, whereas the slope was not altered significantly by relaxation of the in situ arteries. This difference is emphasized by the increased distensibility with relaxation of the in vitro arteries but the decreased distensibility with relaxation of the in situ arteries. The results of this study suggest that, at least in the cat, small pulmonary arteries possess a mechanism that is dormant in the in situ environment within the normal lung. However, the potential for pressure-induced constriction may be unmasked by changing the vessel history and/or environment. Extrapolating results obtained from in vitro pulmonary arteries to the in situ situation should therefore be done with caution. Studies directed at what factors contribute to differences in the responses of in vitro and in situ arteries might help in understanding pulmonary vascular pathophysiology.
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Madden JA, Keller PA, Choy JS, Alvarez TA, Hacker AD. L-arginine-related responses to pressure and vasoactive agents in monocrotaline-treated rat pulmonary arteries. J Appl Physiol (1985) 1995; 79:589-93. [PMID: 7592222 DOI: 10.1152/jappl.1995.79.2.589] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
To determine whether altered NO production contributes to attenuated distensibility (alpha), vasoreactivity, and acetylcholine (ACh) dilation in pulmonary arteries from monocrotaline (MCT)-treated rats (J.A. Madden, P.A. Keller, R. M. Effrosa, C. Sequitte, J.S. Choy, and A.D. Hacker. J. Appl. Physiol. 76: 1589-1593, 1994), intralobar and sidebranch arteries from rats 21 days after MCT treatment were cannulated and pressurized and their diameter changes in response to KCl, norepinephrine, angiotensin II, and pressure were measured in the presence of N omega-nitro-L-arginine (NLA) and L-arginine. NLA treatment decreased MCT artery diameters more than normal arteries (P < 0.05) and abolished ACh dilation in both. Agonist responses were greater in normal but not MCT arteries. The alpha increased in NLA-treated normal (P < 0.05) but not MCT arteries. After L-arginine, normal and MCT arteries returned to control diameters and dilated to ACh. Agonist responses returned to control in normal but not MCT arteries. Normal but not MCT arteries dilated in calcium-free solution (P < 0.05). These results suggest that pulmonary arteries from rats with MCT-induced pulmonary hypertension produce more NO than do pulmonary arteries; inhibiting NO does not increase contractility; and decreased vasoreactivity and alpha values are not due to smooth muscle cell tone but may be due to abnormal vascular remodeling.
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