36 results on '"Davis PA"'
Search Results
2. AI-Powered Telemedicine for Automatic Scoring of Neuromuscular Examinations
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Quentin Lesport, Davis Palmie, Gülşen Öztosun, Henry J. Kaminski, and Marc Garbey
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telehealth ,telemedicine ,myasthenia gravis ,ptosis ,diplopia ,neurological disease ,Technology ,Biology (General) ,QH301-705.5 - Abstract
Telemedicine is now being used more frequently to evaluate patients with myasthenia gravis (MG). Assessing this condition involves clinical outcome measures, such as the standardized MG-ADL scale or the more complex MG-CE score obtained during clinical exams. However, human subjectivity limits the reliability of these examinations. We propose a set of AI-powered digital tools to improve scoring efficiency and quality using computer vision, deep learning, and natural language processing. This paper focuses on automating a standard telemedicine video by segmenting it into clips corresponding to the MG-CE assessment. This AI-powered solution offers a quantitative assessment of neurological deficits, improving upon subjective evaluations prone to examiner variability. It has the potential to enhance efficiency, patient participation in MG clinical trials, and broader applicability to various neurological diseases.
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- 2024
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3. Assessing the Feasibility of Rural Residency Training for Licensed Naturopathic Physicians in the Northwest: A Qualitative Study
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Luciano Garofalo, Thomas Bell, Gena Poling, and Davis Patterson
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naturopathic ,residency ,rural ,primary care ,underserved ,education ,Other systems of medicine ,RZ201-999 - Abstract
Objectives: Naturopathic physicians (ND) are uniquely situated to address areas of unmet health care need as primary care providers (PCPs). In several states, NDs have a broad scope of practice and are licensed as independent practitioners regardless of residency training. However, with a larger role in the health care system, the need for post-graduate medical training becomes more important for clinical success and patient safety. Our study aimed at assessing the feasibility of developing residencies for licensed NDs in rural federally qualified health centers (FQHCs) of Oregon and Washington. Methods: We conducted interviews with leadership from a convenience sample of eight FQHCs. Six centers were rural, two of which already employed NDs. Two urban centers that employed NDs as PCPs were included for their valuable insights related to study design. Two investigators independently reviewed and coded site visit notes for prominent themes through inductive reasoning analysis. Results: Consensus was met identifying the following themes: onboarding and mentorship; diversity of clinical training; financial structure; length of residency; and addressing health care needs in the community. We identified several opportunities for the development of primary care residencies for NDs, including the need for PCPs in rural communities, the ability of NDs to manage chronic pain with prescription drugs, and the prevention of morbidity from complex conditions such as diabetes and cardiovascular disease. Potential barriers to residency development include lack of Medicare reimbursement, mixed awareness of the ND scope of practice, and scarcity of dedicated mentors. Conclusion: These results may serve as guideposts for the future development of naturopathic residencies in rural community health centers.
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- 2023
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4. Third Party Reports influence parents’ perceptions of coaching ability: Implications for youth sport coaches
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Manley, AJ, Woodward, J, Davis, PA, and Thelwell, RC
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According to Olson, Roese, and Zanna’s (1996) Model of Expectancy Processes, information conveyed by others can determine our expectancies of people. Furthermore, Third Party Reports (TPRs) such as reputation may influence athletes’ initial expectancies of coaches (e.g., Manley et al., 2008; 2010; Thelwell et al., 2013). Parents are believed to play a fundamental role in the development of coach-athlete relationships (e.g., Jowett & Katchis, 2005) and, in turn, athletic achievement in youth sport (Gould et al., 2008). However, person perception research has not yet examined the impact of cues such as TPRs on the initial impressions and expectancies that parents form of youth sport coaches. The current study addresses this gap in the literature. Athletes’ parents viewed a hypothetical online report describing the appointment of a new coach at a local sports club. The report included a “comments” section, which consisted of “tweets” posted by the newly-appointed coach’s former athletes. Four experimental conditions were created by manipulating the coach’s level of warmth and competence (i.e., high vs. low) as reported through the “comments/tweets” (i.e., TPRs). After reading the online report, participants provided ratings of the coach’s ability using the Coaching Competency Questionnaire (Myers et al., 2006). Participants are currently being recruited via gatekeepers at sports clubs/organisations, as well as through social media. However, based on an initial sample (n = 83), Kruskal-Wallis tests typically revealed that high-warmth/high-competence TPRs resulted in highest evaluations of overall coaching ability, while TPRs low in both warmth and competence received poorest ratings. Interestingly, perceptions of Character-building Competence were highest for high-warmth/low-competence TPRs. These preliminary findings reveal that TPRs can influence parents’ perceptions of coaching proficiency, but that parents may value warmth over competence when assessing a coach’s ability to develop more holistic qualities in youth sport athletes.
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- 2016
5. Effect of aldosterone and glycyrrhetinic acid on the protein expression of PAI-1 and p22(phox) in human mononuclear leukocytes
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Calo', Lorenzo, Zaghetto, F, Pagnin, Elisa, Davis, Pa, DE MOZZI, P, Sartorato, Paola, Martire, G, Fiore, Cristina, Armanini, Decio, and Calo', Pa
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Adult ,Male ,medicine.medical_specialty ,Aldosterone ,Glycyrrhetinic acid ,Mononuclear leukocytes ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,medicine.disease_cause ,Biochemistry ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Canrenone ,Plasminogen Activator Inhibitor 1 ,medicine ,Humans ,Receptor ,Enoxolone ,Mineralocorticoid Receptor Antagonists ,biology ,Dose-Response Relationship, Drug ,Biochemistry (medical) ,NADPH Dehydrogenase ,Membrane Transport Proteins ,NADPH Oxidases ,Drug Synergism ,medicine.disease ,Phosphoproteins ,Hyperaldosteronism ,chemistry ,Mineralocorticoid ,biology.protein ,Leukocytes, Mononuclear ,Glycyrrhetinic Acid ,Female ,P22phox ,Oxidative stress ,medicine.drug - Abstract
Aldosterone excess can produce heart and kidney fibrosis, which seem to be related to a direct effect of aldosterone at the level of specific receptors. We report a direct, mineralocorticoid-mediated effect on the protein expression of two markers of oxidative stress after incubation of mononuclear leukocytes with 1 × 10−8m aldosterone (p22phox/β-actin = 1.38 ± 0.05 and PAI-1/β-actin = 1.80 ± 0.05). The same effect was also found with 3 × 10−5m glycyrrhetinic acid, the principal constituent of licorice root (p22phox/β-actin = 1.37 ± 0.97 and PAI-1/β-actin = 1.80 ± 0.04). The effect of both aldosterone and glycyrrhetinic acid is blocked by incubation with added 1 × 10−6m of receptor-antagonist canrenone. Canrenone alone did not show any effect. PAI-1 related protein was also found using 4 × 10−9m aldosterone. Incubations with 1 × 10−9m for 3 hours as well as 1 × 10−8m aldosterone for 5, 10, and 20 minutes were ineffective for both proteins. These data support the previous finding of an involvement of mononuclear leukocytes in the pathogenesis of the oxidative stress induced by hyperaldosteronism. In addition, the results confirm our previous data on a direct effect of glycyrrhetinic acid at the level of mineralocorticoid receptors.
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- 2004
6. Impact Evaluation of an Emerging European Health Project – the MIDAS Model
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Connolly Justin, Staines Anthony, Connolly Regina, Davis Paul, and Boilson Andrew
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midas ,health-based project ,decision support systems ,data mining ,i18 ,Business ,HF5001-6182 - Abstract
Background: This paper describes the impact evaluation of a large big data platform initiative that is being undertaken in order to increase the probability of its success. The initiative, MIDAS (Meaningful Integration of Data Analytics and Services), is a European health-based Horizon 2020 project comprising a consortium of members from various universities, research institutions, and government agencies.
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- 2020
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7. Health Technology Assessment: The Role of Total Cost of Ownership
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McConalogue Eoghan, Davis Paul, and Connolly Regina
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technology assessment ,ambient assisted living ,total cost of ownership ,health systems ,procurement ,Business ,HF5001-6182 - Abstract
Background: Recently the European Union, through its Horizon 2020 fund has awarded numerous research projects tasked with the development of cloud-based health technology solutions. A number of these projects have a specific focus on ambient assisted living (AAL) technologies; solutions that offer a unique opportunity to improve the quality of life of persons with mild cognitive impairments. The diffusion of these solutions across a European wide cloud infrastructure presents a novel opportunity to reduce economic pressures currently experienced by European health systems. However, no route to market framework currently exists for a European wide healthcare delivery system. Objectives: The goal of the paper is to conduct the review and develop the literature around technology assessment for AAL technologies and route to market frameworks. Methods/Approach: We highlight the role of Total Cost of Ownership (TCO) when conducting a technology assessment by reviewing existent literature. Results: We discuss three TCO models that can support the assessment of AAL technologies. Conclusions: There is a gap in the analysis of TCO models in the context of AAL technologies particularly in public and private sector collaborations. TCO process should be developed into a key award criterion when conducting AAL technology assessment and procurements, thus aiding long term strategic decision making.
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- 2019
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8. Flexible granulocyte colony-stimulating factor dosing in ovarian cancer patients who receive dose-intense taxol therapy
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Link, CJ Jr, primary, Bicher, A, additional, Kohn, EC, additional, Christian, MC, additional, Davis, PA, additional, Adamo, DO, additional, Reed, E, additional, and Sarosy, GA, additional
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- 1994
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9. Antiinflammatory effects of salmeterol/fluticasone propionate in chronic obstructive lung disease.
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Barnes NC, Qiu Y, Pavord ID, Parker D, Davis PA, Zhu J, Johnson M, Thomson NC, Jeffery PK, and SCO30005 Study Group
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Rationale: No currently available treatment is reported to reduce the exaggerated airway wall inflammation of chronic obstructive pulmonary disease. Objectives: We tested the hypothesis that inhaled combined long-acting beta(2)-agonist (salmeterol) and corticosteroid (fluticasone propionate) will reduce inflammation. Methods: Bronchial biopsies and induced sputum were taken from 140 current and former smokers (mean age, 64 yr) with moderate to severe disease, randomized in a 13-wk double-blind study to placebo (n = 73) or salmeterol/fluticasone propionate 50/500 mug (n = 67) twice daily. Biopsies were repeated at 12 wk and sputa at 8 and 13 wk. After adjustment for multiplicity, comparisons between active and placebo were made for median change from baseline in the numbers of biopsy CD8(+) and CD68(+) cells/mm(2) and sputum neutrophils. Measurements and Main Results: Combination therapy was associated with a reduction in biopsy CD8(+) cells of -118 cells/mm(2) (95% confidence interval [CI], -209 to -42; p = 0.02), a reduction of 36% over placebo (p = 0.001). CD68(+) cells were unaffected by combination treatment. Sputum differential (but not total) neutrophils reduced progressively and, at Week 13, significantly with combination treatment (median treatment difference, 8.5%; 95% CI, 1.75%-15.25%; p = 0.04). The combination also significantly reduced biopsy CD45(+) and CD4(+) cells and cells expressing genes for tumor necrosis factor-alpha and IFN-gamma and sputum total eosinophils (all p = 0.03). These antiinflammatory effects were accompanied by a 173-ml (95% CI, 104-242; p < 0.001) improvement in prebronchodilator FEV(1). Conclusions: The combination of salmeterol and fluticasone propionate has a broad spectrum of antiinflammatory effects in both current and former smokers with chronic obstructive pulmonary disease, which may contribute to clinical efficacy. [ABSTRACT FROM AUTHOR]
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- 2006
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10. Reduced oxidative susceptibility of LDL from patients participating in an intensive atherosclerosis treatment program.
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Parks EJ, German JB, Davis PA, Frankel EN, Kappagoda CT, Rutledge JC, Hyson DA, and Schneeman BO
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The goal of this investigation was to determine whether participation in an atherosclerosis treatment program would reduce the oxidative susceptibility of LDL from patients with coronary artery disease. The treatment program included intensive exercise therapy, stress management, and consumption of a diet containing 10% fat. The size and antioxidant and lipid contents of LDL particles from 25 patients were analyzed at baseline and after 3 mo of therapy. The susceptibility of LDL to copper-mediated oxidation was measured by a conjugated diene assay and headspace gas chromatography (HSGC). Atherosclerosis treatment significantly reduced plasma total cholesterol and apolipoprotein B concentrations and the molar ratio of LDL cholesterol ester to apolipoprotein B (P < 0.01). The LDL content of alpha-tocopherol and beta-carotene was increased (27% and 17%, respectively, P < 0.04) and the molar ratio of LDL cholesterol ester the sum of LDL alpha-tocopherol and LDL beta-carotene decreased from 159 at baseline to 122 at 3 mo (P < 0.01). The lag phase of LDL conjugated diene formation increased 24%, whereas the maximum rate of oxidation slowed 29% (P < 0.01). As assessed by HSGC, copper-catalyzed formation of volatile lipid oxidation products was reduced 15% (P < 0.007); the reduction in volatiles was correlated with an increase in the alpha-tocopherol content of LDL (r=-0.48, P < 0.01). The principal determinants of reduced LDL oxidative susceptibility were the particle contents of alpha-tocopherol and beta-carotene. To our knowledge, this is the first report to document a reduction in LDL oxidation in coronary artery disease patients undergoing atherosclerosis-reversal therapy. Copyright (c) 1998 American Society for Clinical Nutrition [ABSTRACT FROM AUTHOR]
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- 1998
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11. Insulin signaling, glucose metabolism, and the angiotensin II signaling system: studies in Bartter's/Gitelman's syndromes.
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Davis PA, Pagnin E, Semplicini A, Avogaro A, Calò LA, Davis, Paul A, Pagnin, Elisa, Semplicini, Andrea, Avogaro, Angelo, and Calò, Lorenzo A
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- 2006
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12. Assessing pharmacists’ perspectives of HIV and the care of HIV-infected patients in Alabama
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Davis Pate M, Shell AT, and King SR
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Acquired Immunodeficiency Syndrome ,Health Knowledge ,Attitudes ,Practice ,Pharmacists ,United States ,Therapeutics. Pharmacology ,RM1-950 ,Pharmacy and materia medica ,RS1-441 - Abstract
Objective: The purpose was to assess factors potentially affecting care pharmacists provide to HIV/AIDS patients including comfort level, confidence, education, experience, professional competence, continuity of care and patient-provider relationship between pharmacists and HIV-infected patients.Methods: A 24-item questionnaire assessed the constructs of this study. Surveys were distributed from October 2009 to April 2010 to pharmacists in Alabama with varying levels of experience treating HIV-infected patients. Chi-square tests determined whether relationships existed between responses, consisting of how often respondents reported treating HIV-infected patients, amount of HIV education respondents had, participants’ confidence with HIV/AIDS knowledge and comfort level counseling HIV-infected patients about their medications.Results: Thirty-three percent of the pharmacists cared for HIV-infected patients on a monthly basis, yet 86% do not feel very confident with their HIV/AIDS knowledge. Forty-four percent were not comfortable counseling patients on antiretroviral medications, and 77% would feel more comfortable with more education. Significant, positive relationships were revealed concerning how often respondents treat HIV-infected patients and their comfort level counseling them (r=0.208, p
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- 2012
13. A simplified counter-selection recombineering protocol for creating fluorescent protein reporter constructs directly from C. elegans fosmid genomic clones
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Hirani Nisha, Westenberg Marcel, Gami Minaxi S, Davis Paul, Hope Ian A, and Dolphin Colin T
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C. elegans ,Recombineering ,Fosmid ,Fluorescent protein ,Deoxyribose-phosphate aldolase ,Peroxiredoxin ,Metallocarboxypeptidase ,Biotechnology ,TP248.13-248.65 - Abstract
Abstract Background Recombineering is a genetic engineering tool that enables facile modification of large episomal clones, e.g. BACs, fosmids. We have previously adapted this technology to generate, directly from fosmid-based genomic clones, fusion gene reporter constructs designed to investigate gene expression patterns in C. elegans. In our adaptation a rpsL-tet(A) positive/negative-selection cassette (RT-cassette) is first inserted and then, under negative selection, seamlessly replaced with the desired sequence. We report here on the generation and application of a resource comprising two sets of constructs designed to facilitate this particular recombineering approach. Results Two complementary sets of constructs were generated. The first contains different fluorescent protein reporter coding sequences and derivatives while the second set of constructs, based in the copy-number inducible vector pCC1Fos, provide a resource designed to simplify RT-cassette-based recombineering. These latter constructs are used in pairs the first member of which provides a template for PCR-amplification of an RT-cassette while the second provides, as an excised restriction fragment, the desired fluorescent protein reporter sequence. As the RT-cassette is flanked by approximately 200 bp from the ends of the reporter sequence the subsequent negative selection replacement step is highly efficient. Furthermore, use of a restriction fragment minimizes artefacts negating the need for final clone sequencing. Utilizing this resource we generated single-, double- and triple-tagged fosmid-based reporters to investigate expression patterns of three C. elegans genes located on a single genomic clone. Conclusions We describe the generation and application of a resource designed to facilitate counter-selection recombineering of fosmid-based C. elegans genomic clones. By choosing the appropriate pair of ‘insertion’ and ‘replacement’ constructs recombineered products, devoid of artefacts, are generated at high efficiency. Gene expression patterns for three genes located on the same genomic clone were investigated via a set of fosmid-based reporter constructs generated with the modified protocol.
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- 2013
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14. Advancing clinical decision support using lessons from outside of healthcare: an interdisciplinary systematic review
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Wu Helen W, Davis Paul K, and Bell Douglas S
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Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Abstract Background Greater use of computerized decision support (DS) systems could address continuing safety and quality problems in healthcare, but the healthcare field has struggled to implement DS technology. This study surveys DS experience across multiple non-healthcare disciplines for new insights that are generalizable to healthcare provider decisions. In particular, it sought design principles and lessons learned from the other disciplines that could inform efforts to accelerate the adoption of clinical decision support (CDS). Methods Our systematic review drew broadly from non-healthcare databases in the basic sciences, social sciences, humanities, engineering, business, and defense: PsychINFO, BusinessSource Premier, Social Sciences Abstracts, Web of Science, and Defense Technical Information Center. Because our interest was in DS that could apply to clinical decisions, we selected articles that (1) provided a review, overview, discussion of lessons learned, or an evaluation of design or implementation aspects of DS within a non-healthcare discipline and (2) involved an element of human judgment at the individual level, as opposed to decisions that can be fully automated or that are made at the organizational level. Results Clinical decisions share some similarities with decisions made by military commanders, business managers, and other leaders: they involve assessing new situations and choosing courses of action with major consequences, under time pressure, and with incomplete information. We identified seven high-level DS system design features from the non-healthcare literature that could be applied to CDS: providing broad, system-level perspectives; customizing interfaces to specific users and roles; making the DS reasoning transparent; presenting data effectively; generating multiple scenarios covering disparate outcomes (e.g., effective; effective with side effects; ineffective); allowing for contingent adaptations; and facilitating collaboration. The article provides examples of each feature. The DS literature also emphasizes the importance of organizational culture and training in implementation success. The literature contrasts “rational-analytic” vs. “naturalistic-intuitive” decision-making styles, but the best approach is often a balanced approach that combines both styles. It is also important for DS systems to enable exploration of multiple assumptions, and incorporation of new information in response to changing circumstances. Conclusions Complex, high-level decision-making has common features across disciplines as seemingly disparate as defense, business, and healthcare. National efforts to advance the health information technology agenda through broader CDS adoption could benefit by applying the DS principles identified in this review.
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- 2012
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15. Automatic categorization of diverse experimental information in the bioscience literature
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Fang Ruihua, Schindelman Gary, Auken Kimberly, Fernandes Jolene, Chen Wen, Wang Xiaodong, Davis Paul, Tuli Mary, Marygold Steven J, Millburn Gillian, Matthews Beverley, Zhang Haiyan, Brown Nick, Gelbart William M, and Sternberg Paul W
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background Curation of information from bioscience literature into biological knowledge databases is a crucial way of capturing experimental information in a computable form. During the biocuration process, a critical first step is to identify from all published literature the papers that contain results for a specific data type the curator is interested in annotating. This step normally requires curators to manually examine many papers to ascertain which few contain information of interest and thus, is usually time consuming. We developed an automatic method for identifying papers containing these curation data types among a large pool of published scientific papers based on the machine learning method Support Vector Machine (SVM). This classification system is completely automatic and can be readily applied to diverse experimental data types. It has been in use in production for automatic categorization of 10 different experimental datatypes in the biocuration process at WormBase for the past two years and it is in the process of being adopted in the biocuration process at FlyBase and the Saccharomyces Genome Database (SGD). We anticipate that this method can be readily adopted by various databases in the biocuration community and thereby greatly reducing time spent on an otherwise laborious and demanding task. We also developed a simple, readily automated procedure to utilize training papers of similar data types from different bodies of literature such as C. elegans and D. melanogaster to identify papers with any of these data types for a single database. This approach has great significance because for some data types, especially those of low occurrence, a single corpus often does not have enough training papers to achieve satisfactory performance. Results We successfully tested the method on ten data types from WormBase, fifteen data types from FlyBase and three data types from Mouse Genomics Informatics (MGI). It is being used in the curation work flow at WormBase for automatic association of newly published papers with ten data types including RNAi, antibody, phenotype, gene regulation, mutant allele sequence, gene expression, gene product interaction, overexpression phenotype, gene interaction, and gene structure correction. Conclusions Our methods are applicable to a variety of data types with training set containing several hundreds to a few thousand documents. It is completely automatic and, thus can be readily incorporated to different workflow at different literature-based databases. We believe that the work presented here can contribute greatly to the tremendous task of automating the important yet labor-intensive biocuration effort.
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- 2012
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16. PLCβ1-SHP-2 complex, PLCβ1 tyrosine dephosphorylation and SHP-2 phosphatase activity: a new part of Angiotensin II signaling?
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Rossi Gian, Dal Maso Lucia, Pagnin Elisa, Davis Paul A, Bordin Luciana, Calò Lorenzo A, Pessina Achille C, and Clari Giulio
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Angiotensin II signaling ,SHP-2 ,PLCβ1 ,SHP-2-PLCβ1 complex ,Medicine - Abstract
Abstract Background Angiotensin II (Ang II) signaling occurs via two major receptors which activate non-receptor tyrosin kinases that then interact with protein tyrosin-phosphatases (PTPs) to regulate cell function. SHP-2 is one such important PTP that also functions as an adaptor to promote downstream signaling pathway. Its role in Ang II signaling remains to be clarified. Results Using cultured normal human fibroblasts, immunoprecipitation and western blots, we show for the first time that SHP-2 and PLCβ1 are present as a preformed complex. Complex PLCβ1 is tyr-phosphorylated basally and Ang II increased SHP-2-PLCβ1 complexes and caused complex associated PLCβ1 tyr-phosphorylation to decline while complex associated SHP-2's tyr-phosphorylation increased and did so via the Ang II type 1 receptors as shown by Ang II type 1 receptor blocker losartan's effects. Moreover, Ang II induced both increased complex phosphatase activity and decreased complex associated PLCβ1 tyr-phosphorylation, the latter response required regulator of G protein signaling (RGS)-2. Conclusions Ang II signals are shown for the first time to involve a preformed SHP-2-PLCβ1 complex. Changes in the complex's PLCβ1 tyr-phosphorylation and SHP-2's tyr-phosphorylation as well as SHP-2-PLCβ1 complex formation are the result of Ang II type 1 receptor activation with changes in complex associated PLCβ1 tyr-phosphorylation requiring RGS-2. These findings might significantly expand the number and complexity of Ang II signaling pathways. Further studies are needed to delineate the role/s of this complex in the Ang II signaling system.
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- 2011
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17. A novel multifunctional oligonucleotide microarray for Toxoplasma gondii
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Chen Feng, Jagalur Manjunatha, Dzierszinski Florence, Behnke Michael, Davis Paul H, Bahl Amit, Shanmugam Dhanasekaran, White Michael W, Kulp David, and Roos David S
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Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background Microarrays are invaluable tools for genome interrogation, SNP detection, and expression analysis, among other applications. Such broad capabilities would be of value to many pathogen research communities, although the development and use of genome-scale microarrays is often a costly undertaking. Therefore, effective methods for reducing unnecessary probes while maintaining or expanding functionality would be relevant to many investigators. Results Taking advantage of available genome sequences and annotation for Toxoplasma gondii (a pathogenic parasite responsible for illness in immunocompromised individuals) and Plasmodium falciparum (a related parasite responsible for severe human malaria), we designed a single oligonucleotide microarray capable of supporting a wide range of applications at relatively low cost, including genome-wide expression profiling for Toxoplasma, and single-nucleotide polymorphism (SNP)-based genotyping of both T. gondii and P. falciparum. Expression profiling of the three clonotypic lineages dominating T. gondii populations in North America and Europe provides a first comprehensive view of the parasite transcriptome, revealing that ~49% of all annotated genes are expressed in parasite tachyzoites (the acutely lytic stage responsible for pathogenesis) and 26% of genes are differentially expressed among strains. A novel design utilizing few probes provided high confidence genotyping, used here to resolve recombination points in the clonal progeny of sexual crosses. Recent sequencing of additional T. gondii isolates identifies >620 K new SNPs, including ~11 K that intersect with expression profiling probes, yielding additional markers for genotyping studies, and further validating the utility of a combined expression profiling/genotyping array design. Additional applications facilitating SNP and transcript discovery, alternative statistical methods for quantifying gene expression, etc. are also pursued at pilot scale to inform future array designs. Conclusions In addition to providing an initial global view of the T. gondii transcriptome across major lineages and permitting detailed resolution of recombination points in a historical sexual cross, the multifunctional nature of this array also allowed opportunities to exploit probes for purposes beyond their intended use, enhancing analyses. This array is in widespread use by the T. gondii research community, and several aspects of the design strategy are likely to be useful for other pathogens.
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- 2010
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18. Differences in the transcriptome signatures of two genetically related Entamoeba histolytica cell lines derived from the same isolate with different pathogenic properties
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Stanley Samuel L, Lotter Hannelore, Matthiesen Jenny, Tillack Manuela, Davis Paul H, Biller Laura, Tannich Egbert, and Bruchhaus Iris
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Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background The availability of two genetically very similar cell lines (A and B) derived from the laboratory isolate Entamoeba histolytica HM-1:IMSS, which differ in their virulence properties, provides a powerful tool for identifying pathogenicity factors of the causative agent of human amoebiasis. Cell line A is incapable inducing liver abscesses in gerbils, whereas interaction with cell line B leads to considerable abscess formation. Phenotypic characterization of both cell lines revealed that trophozoites from the pathogenic cell line B have a larger cell size, an increased growth rate in vitro, an increased cysteine peptidase activity and higher resistance to nitric oxide stress. To find proteins that may serve as virulence factors, the proteomes of both cell lines were previously studied, resulting in the identification of a limited number of differentially synthesized proteins. This study aims to identify additional genes, serving as virulence factors, or virulence markers. Results To obtain a comprehensive picture of the differences between the cell lines, we compared their transcriptomes using an oligonucleotide-based microarray and confirmed findings with quantitative real-time PCR. Out of 6242 genes represented on the array, 87 are differentially transcribed (≥two-fold) in the two cell lines. Approximately 50% code for hypothetical proteins. Interestingly, only 19 genes show a five-fold or higher differential expression. These include three rab7 GTPases, which were found with a higher abundance in the non-pathogenic cell line A. The aig1-like GTPasesare of special interest because the majority of them show higher levels of transcription in the pathogenic cell line B. Only two molecules were found to be differentially expressed between the two cell lines in both this study and our previous proteomic approach. Conclusions In this study we have identified a defined set of genes that are differentially transcribed between the non-pathogenic cell line A and the pathogenic cell line B of E. histolytica. The identification of transcription profiles unique for amoebic cell lines with pathogenic phenotypes may help to elucidate the transcriptional framework of E. histolytica pathogenicity and serve as a basis for identifying transcriptional markers and virulence factors.
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- 2010
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19. Computational prediction of essential genes in an unculturable endosymbiotic bacterium, Wolbachia of Brugia malayi
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Carlow Clotilde KS, Foster Jeremy M, Davis Paul J, Holman Alexander G, and Kumar Sanjay
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Microbiology ,QR1-502 - Abstract
Abstract Background Wolbachia (wBm) is an obligate endosymbiotic bacterium of Brugia malayi, a parasitic filarial nematode of humans and one of the causative agents of lymphatic filariasis. There is a pressing need for new drugs against filarial parasites, such as B. malayi. As wBm is required for B. malayi development and fertility, targeting wBm is a promising approach. However, the lifecycle of neither B. malayi nor wBm can be maintained in vitro. To facilitate selection of potential drug targets we computationally ranked the wBm genome based on confidence that a particular gene is essential for the survival of the bacterium. Results wBm protein sequences were aligned using BLAST to the Database of Essential Genes (DEG) version 5.2, a collection of 5,260 experimentally identified essential genes in 15 bacterial strains. A confidence score, the Multiple Hit Score (MHS), was developed to predict each wBm gene's essentiality based on the top alignments to essential genes in each bacterial strain. This method was validated using a jackknife methodology to test the ability to recover known essential genes in a control genome. A second estimation of essentiality, the Gene Conservation Score (GCS), was calculated on the basis of phyletic conservation of genes across Wolbachia's parent order Rickettsiales. Clusters of orthologous genes were predicted within the 27 currently available complete genomes. Druggability of wBm proteins was predicted by alignment to a database of protein targets of known compounds. Conclusion Ranking wBm genes by either MHS or GCS predicts and prioritizes potentially essential genes. Comparison of the MHS to GCS produces quadrants representing four types of predictions: those with high confidence of essentiality by both methods (245 genes), those highly conserved across Rickettsiales (299 genes), those similar to distant essential genes (8 genes), and those with low confidence of essentiality (253 genes). These data facilitate selection of wBm genes for entry into drug design pipelines.
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- 2009
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20. The effectiveness of behavioural interventions in the primary prevention of Hepatitis C amongst injecting drug users: a randomised controlled trial and lessons learned
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Tibbs Christopher, Corrin Betsy, John Christopher, Godfrey Christine, Maxwell Douglas, Drummond Colin, Checinski Ken, Rice Philip, Davis Paul, Abou-Saleh Mohammed, Oyefeso Adenekan, de Ruiter Marian, and Ghodse Hamid
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Public aspects of medicine ,RA1-1270 - Abstract
Abstract Aim To develop and evaluate the comparative effectiveness of behavioural interventions of enhanced prevention counselling (EPC) and simple educational counselling (SEC) in reducing hepatitis C viral (HCV) infection in sero-negative injecting drug users (IDU). Design Randomised controlled trial (RCT) of EPC intervention in comparison with simple educational counselling (SEC). Setting Specialised Drug services in London and Surrey, United Kingdom. Participants and Measurements Ninety five IDUs were recruited and randomised to receive EPC (n = 43) or SEC (n = 52). Subjects were assessed at baseline using the Addiction Severity Index (ASI), the Injecting Risk Questionnaire (IRQ), and Drug Injecting Confidence Questionnaire (DICQ). The primary outcome was measured by the rate of sero-conversion at 6 months and 12 months from baseline and by the ASI, IRQ and DICQ at 6 months from baseline. Hepatitis C testing was undertaken by the innovative test of the dried blood spot (DBS) test which increased the rate of testing by 4 fold compared to routine blood testing. Findings Seventy Eighty two subjects (82%) out of the 95 recruited were followed up at 6 months and 62 (65%) were followed up at 12 months. On the primary outcome measure of the rate of seroconversion, 8 out of 62 patients followed-up at twelve months seroconverted, three in the EPC group and five in the SEC group, indicating incidence rates of 9.1 per 100 person years for the EPC group, 17.2 per 100 person years for the SEC group, and 12.9 per 100 person years for the cohort as a whole. Analysis of the secondary outcome measures on alcohol use, risk behaviour, psychological measures, quality of life, showed no significant differences between the EPC and the SEC groups. However, there were significant changes on a number of measures from baseline values indicating positive change for both groups. Conclusion We were not able to prove the efficacy of EPC in comparison with SEC in the prevention of hepatitis C in IDUs. This was related to low recruitment and retention rates of the participants. Moreover there was a low adherence rate to EPC. The study provided the benefits of developing and introducing behavioural interventions of the EPC and SEC and the DBS screening for Hepatitis C. Moreover the main lessons learnt were that piloting of a new intervention is a crucial first step before conducting pragmatic RCTs of psychological interventions in the field of addiction; that an infrastructure and culture for psychosocial interventions is needed to enable applied research in the service environment, and research funding is needed for enabling the recruitment of dedicated trained therapists for the delivery of these interventions.
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- 2008
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21. Immunomodulation of murine collagen-induced arthritis by N, N-dimethylglycine and a preparation of Perna canaliculus
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Davis Paul, Whitesides John F, Belkowski Stanley M, Lawson Brian R, and Lawson John W
- Subjects
Other systems of medicine ,RZ201-999 - Abstract
Abstract Background Rheumatoid arthritis (RA) and its accepted animal model, murine collagen-induced arthritis (CIA), are classic autoimmune inflammatory diseases which require proinflammatory cytokine production for pathogenesis. We and others have previously used N, N-dimethylglycine (DMG) and extracts from the New Zealand green-lipped mussel Perna canaliculus (Perna) as potent immunomodulators to modify ongoing immune and/or inflammatory responses. Methods In our initial studies, we treated lipopolysaccahride (LPS) stimulated THP-1 monocytes in vitro with increasing concentrations of Perna extract or DMG. Additionally, we treated rat peripheral blood neutrophils with increasing concentrations of Perna extract and measured superoxide burst. In subsequent in vivo experiments, CIA was induced by administration of type II collagen; rats were prophylactically treated with either Perna or DMG, and then followed for disease severity. Finally, to test whether Perna and/or DMG could block or inhibit an ongoing pathologic disease process, we induced CIA in mice and treated them therapeutically with either of the two immunomodulators. Results Following LPS stimulation of THP-1 monocytes, we observed dose-dependent reductions in TNF-α and IL-12p40 production in Perna treated cultures. DMG treatment, however, showed significant increases in both of these cytokines in the range of 0.001–1 μM. We also demonstrate that in vitro neutrophil superoxide burst activity is dose-dependently reduced in the presence of Perna. Significant reductions in disease incidence, onset, and severity of CIA in rats were noted following prophylactic treatment with either of the two immunomodulators. More importantly, amelioration of mouse CIA was observed following therapeutic administration of Perna. In contrast, DMG appeared to have little effect in mice and may act in a species-specific manner. Conclusion These data suggest that Perna, and perhaps DMG, may be useful supplements to the treatment of RA in humans.
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- 2007
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22. Mast cells dysregulate apoptotic and cell cycle genes in mucosal squamous cell carcinoma
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Davis Paul, Yuan Lan, Sullivan Michael, Ch'ng Sydney, and Tan Swee T
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 ,Cytology ,QH573-671 - Abstract
Abstract Background Mucosal squamous cell carcinoma of the head and neck is a disease of high mortality and morbidity. Interactions between the squamous cell carcinoma and the host's local immunity, and how the latter contributes to the biological behavior of the tumor are unclear. In vivo studies have demonstrated sequential mast cell infiltration and degranulation during squamous cell carcinogenesis. The degree of mast cell activation correlates closely with distinct phases of hyperkeratosis, dysplasia, carcinoma in-situ and invasive carcinoma. However, the role of mast cells in carcinogenesis is unclear. Aim This study explores the effects of mast cells on the proliferation and gene expression profile of mucosal squamous cell carcinoma using human mast cell line (HMC-1) and human glossal squamous cell carcinoma cell line (SCC25). Methods HMC-1 and SCC25 were co-cultured in a two-compartment chamber, separated by a polycarbonate membrane. HMC-1 was stimulated to degranulate with calcium ionophore A23187. The experiments were done in quadruplicate. Negative controls were established where SCC25 were cultured alone without HMC-1. At 12, 24, 48 and 72 hours, proliferation and viability of SCC25 were assessed with MTT colorimetric assay. cDNA microarray was employed to study differential gene expression between co-cultured and control SCC25. Results HMC-1/SCC25 co-culture resulted in suppression of growth rate for SCC-25 (34% compared with 110% for the control by 72 hours, p < 0.001), and dysregulation of genes TRAIL, BIRC4, CDK6, Cyclin G2 and CDC6 in SCC25. Conclusion We show that mast cells have a direct inhibitory effect on the proliferation of mucosal squamous cell carcinoma in vitro by dysregulating key genes in apoptosis and cell cycle control.
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- 2006
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23. Relation of exaggerated cytokine responses of CF airway epithelial cells to PAO1 adherence
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Davis Pamela B, Fletcher David, and Kube Dianne M
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Cystic Fibrosis ,Inflammation ,Pseudomonas aeruginosa ,IL-8 ,Neuraminidase ,Tight junctions ,Diseases of the respiratory system ,RC705-779 - Abstract
Abstract In many model systems, cystic fibrosis (CF) phenotype airway epithelial cells in culture respond to P. aeruginosa with greater interleukin (IL)-8 and IL-6 secretion than matched controls. In order to test whether this excess inflammatory response results from the reported increased adherence of P. aeruginosa to the CF cells, we compared the inflammatory response of matched pairs of CF and non CF airway epithelial cell lines to the binding of GFP-PAO1, a strain of pseudomonas labeled with green fluorescent protein. There was no clear relation between GFP-PAO1 binding and cytokine production in response to PAO1. Treatment with exogenous aGM1 resulted in greater GFP-PAO1 binding to the normal phenotype compared to CF phenotype cells, but cytokine production remained greater from the CF cell lines. When cells were treated with neuraminidase, PAO1 adherence was equalized between CF and nonCF phenotype cell lines, but IL-8 production in response to inflammatory stimuli was still greater in CF phenotype cells. The polarized cell lines 16HBEo-Sense (normal phenotype) and Antisense (CF phenotype) cells were used to test the effect of disrupting tight junctions, which allows access of PAO1 to basolateral binding sites in both cell lines. IL-8 production increased from CF, but not normal, cells. These data indicate that increased bacterial binding to CF phenotype cells cannot by itself account for excess cytokine production in CF airway epithelial cells, encourage investigation of alternative hypotheses, and signal caution for therapeutic strategies proposed for CF that include disruption of tight junctions in the face of pseudomonas infection.
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- 2005
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24. Acute cryoglobulinemic vasculitis following rituximab infusion for waldenström macroglobulinemia
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Zach Thornton, BA, Melissa Davis, PA-C, and Cindy E. Owen, MD
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cryoglobulinemia ,leukocytoclastic vasculitis ,rituximab ,Waldenstrom macroglobulinemia ,Dermatology ,RL1-803 - Published
- 2023
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25. State of the Art: Why do the lungs of patients with cystic fibrosis become infected and why can't they clear the infection?
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Davis Pamela B and Chmiel James F
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cystic fibrosis ,cystic fibrosis transmembrane conductance regulator ,inflammation ,lung ,Pseudomonas aeruginosa ,Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Cystic Fibrosis (CF) lung disease, which is characterized by airway obstruction, chronic bacterial infection, and an excessive inflammatory response, is responsible for most of the morbidity and mortality. Early in life, CF patients become infected with a limited spectrum of bacteria, especially P. aeruginosa. New data now indicate that decreased depth of periciliary fluid and abnormal hydration of mucus, which impede mucociliary clearance, contribute to initial infection. Diminished production of the antibacterial molecule nitric oxide, increased bacterial binding sites (e.g., asialo GM-1) on CF airway epithelial cells, and adaptations made by the bacteria to the airway microenvironment, including the production of virulence factors and the ability to organize into a biofilm, contribute to susceptibility to initial bacterial infection. Once the patient is infected, an overzealous inflammatory response in the CF lung likely contributes to the host's inability to eradicate infection. In response to increased IL-8 and leukotriene B4 production, neutrophils infiltrate the lung where they release mediators, such as elastase, that further inhibit host defenses, cripple opsonophagocytosis, impair mucociliary clearance, and damage airway wall architecture. The combination of these events favors the persistence of bacteria in the airway. Until a cure is discovered, further investigations into therapies that relieve obstruction, control infection, and attenuate inflammation offer the best hope of limiting damage to host tissues and prolonging survival.
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- 2003
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26. Phosphorus in excess: a 'nutrient pollution' problem in the blood-broken hearts like broken lakes (eutrophication)?
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Calò LA, Savica V, and Davis PA
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- 2009
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27. Tree nut and peanut consumption in relation to chronic and metabolic diseases including allergy.
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Davis PA, Jenab M, Vanden Heuvel JP, Furlong T, Taylor S, Davis, Paul A, Jenab, Mazda, Vanden Heuvel, John P, Furlong, Terence, and Taylor, Steve
- Abstract
The New and Emerging Research session highlighted the emerging understanding of both the positive and negative effects of nuts consumption on health. The limited nature of both experimental and epidemiological evidence for positive relationship(s) between nut intake and health were noted. Study inconsistency and limitations, particularly survey methodology, were explored. Recent results from epidemiologic studies indicating a potential negative association between nut and seed intake and cancer risk were reviewed. The ability of walnuts to reduce endothelin suggests an interesting biochemical mechanism of nut action that may affect other endothelin-associated diseases, which should be further explored. The effects of nuts and their constituents on a nuclear receptor screen (PPARalpha, beta/delta, gamma, LXRalpha, beta, RXRalpha, beta, gamma, PXR, and FXR) have been explored. Nut allergenicity and approaches necessary to minimize this effect were also described. In contrast to the positive effects, nut allergies present tree nut-allergic consumers with health challenges. The Food Allergy and Anaphylaxis Network stressed the importance of ensuring that consumers with food allergies have legible, accurate food labels. The Food Allergen Labeling and Consumer Protection Act has engendered precautionary, worst-case allergen scenario labeling statements with unknown benefits to consumer health. Issues of cross-contamination due to shared equipment and shared facilities highlighted the need to rely on allergen control programs that use ELISA technology and have increased understanding of nut allergens. Ultimately, to maximize the positive benefits of nuts, the consumer must be provided with all the information required to make an informed choice. [ABSTRACT FROM AUTHOR]
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- 2008
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28. Oxidative stress and the altered reaction to it in Fabry disease: A possible target for cardiovascular-renal remodeling?
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Ravarotto V, Carraro G, Pagnin E, Bertoldi G, Simioni F, Maiolino G, Martinato M, Landini L, Davis PA, and Calò LA
- Subjects
- Adult, Aged, Cyclic AMP metabolism, Enzyme Replacement Therapy, Fabry Disease complications, Fabry Disease therapy, Female, Heme Oxygenase-1 metabolism, Humans, Hypertrophy, Left Ventricular etiology, Hypertrophy, Left Ventricular pathology, Isoenzymes therapeutic use, Kidney metabolism, Lipid Peroxidation, MAP Kinase Signaling System, Male, Middle Aged, Myosin-Light-Chain Phosphatase metabolism, NADPH Oxidases metabolism, Recombinant Proteins therapeutic use, Vascular Remodeling drug effects, alpha-Galactosidase therapeutic use, rho-Associated Kinases metabolism, Fabry Disease metabolism, Oxidative Stress drug effects
- Abstract
Background: Fabry disease is characterized by deficient expression/activity of α-GalA with consequent lysosomal accumulation in various organs of its substrate Gb3. Despite enzyme replacement therapy, Fabry disease progresses with serious myocardial, cerebral and renal manifestations. Gb3 accumulation may induce oxidative stress (OxSt), production of inflammatory cytokines and reduction of nitric oxide, which may impact on Fabry disease's clinical manifestations., Methods: OxSt status was characterized in 10 patients compared with 10 healthy subjects via protein expression of p22phox, subunit of NADH/NADPH oxidase, (Western blot), Heme oxygenase (HO)-1 levels (ELISA), antioxidant/anti-inflammatory, lipid peroxidation as malondialdehyde (MDA) production (colorimetric assay), phosphorylation state of Extracellular Signal Regulated Kinase (ERK)1/2 and Myosin Phosphatase Target Protein (MYPT)-1 (Western blot), marker of Rho kinase activation, both involved in OxSt signaling. Cardiac left ventricular (LV) mass was also evaluated (M-mode echocardiography)., Results: LV mass was higher in Fabry's males (123.72±2.03SEM g/m2) and females (132.09±6.72g/m2). p22phox expression was also higher in patients (1.04±0.09 d.u. vs 0.54±0.05 d.u. p<0.01) as well as MDA levels (54.51±3.97 vs 30.05±7.11 nmol/mL p = 0.01) while HO-1 was reduced (8.84±0.79 vs 14.03±1.23 ng/mL, p<0.02). MYPT-1's phosphorylation was increased in patients (0.52±0.11 d.u. vs 0.03±0.08 d.u., p<0.01) while phosphorylation of ERK1/2 was reduced (0.91±0.08 d.u. vs 1.53±0.17 d.u., p = 0.004)., Conclusions: This study documents OxSt activation and the altered reaction to it in Fabry patients. Cardiac remodeling, Rho kinase signaling activation and reduction of protective HO-1 might suggest that, in addition to enzyme replacement therapy, OxSt inhibition by either pharmacological or nutritional measures, is likely to prove useful for the prevention/treatment of Fabry patients' cardiovascular-renal remodeling., Competing Interests: This study was supported by an unrestricted grant from Sanofi- Genzyme. Linda Landini is employed by Sanofi-Genzyme. There are no patents, products in development or marketed products to declare. This does not alter our adherence to all the PLOS ONE policies on sharing data and materials.
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- 2018
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29. TRAMP prostate tumor growth is slowed by walnut diets through altered IGF-1 levels, energy pathways, and cholesterol metabolism.
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Kim H, Yokoyama W, and Davis PA
- Subjects
- Adenocarcinoma metabolism, Animals, Cholesterol blood, Dietary Fats analysis, Energy Metabolism, Male, Mice, Mice, Inbred C57BL, Mice, Transgenic, Prostate metabolism, Prostatic Neoplasms metabolism, RNA, Messenger metabolism, Tocopherols therapeutic use, Adenocarcinoma diet therapy, Insulin-Like Growth Factor I metabolism, Juglans chemistry, Lipoproteins metabolism, Plant Oils therapeutic use, Prostatic Neoplasms diet therapy
- Abstract
Dietary changes could potentially reduce prostate cancer morbidity and mortality. Transgenic adenocarcinoma of the mouse prostate (TRAMP) prostate tumor responses to a 100 g of fat/kg diet (whole walnuts, walnut oil, and other oils; balanced for macronutrients, tocopherols [α-and γ]) for 18 weeks ad libitum were assessed. TRAMP mice (n=17 per group) were fed diets with 100 g fat from either whole walnuts (diet group WW), walnut-like fat (diet group WLF, oils blended to match walnut's fatty acid profile), or as walnut oil (diet group WO, pressed from the same walnuts as WW). Fasted plasma glucose was from tail vein blood, blood was obtained by cardiac puncture, and plasma stored frozen until analysis. Prostate (genitourinary intact [GUI]) was weighed and stored frozen at -80°C. Plasma triglyceride, lipoprotein cholesterol, plasma multianalyte levels (Myriad RBM Rat Metabolic MAP), prostate (GUI), tissue metabolites (Metabolon, Inc., Durham, NC, USA), and mRNA (by Illumina NGS) were determined. The prostate tumor size, plasma insulin-like growth factor-1 (IGF-1), high density lipoprotein, and total cholesterol all decreased significantly (P<.05) in both WW and WO compared to WLF. Both WW and WO versus WLF showed increased insulin sensitivity (Homeostasis Model Assessment [HOMA]), and tissue metabolomics found reduced glucose-6-phosphate, succinylcarnitine, and 4-hydroxybutyrate in these groups suggesting effects on cellular energy status. Tissue mRNA levels also showed changes suggestive of altered glucose metabolism with WW and WO diet groups having increased PCK1 and CIDEC mRNA expression, known for their roles in gluconeogenesis and increased insulin sensitivity, respectively. WW and WO group tissues also had increased MSMB mRNa a tumor suppressor and decreased COX-2 mRNA, both reported to inhibit prostate tumor growth. Walnuts reduced prostate tumor growth by affecting energy metabolism along with decreased plasma IGF-1 and cholesterol. These effects are not due to the walnut's N-3 fatty acids, but due to component(s) found in the walnut's fat component.
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- 2014
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30. OBT/HTO ratio in agricultural produce subject to routine atmospheric releases of tritium.
- Author
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Korolevych VY, Kim SB, and Davis PA
- Subjects
- Atmosphere, Models, Theoretical, Radiation Monitoring, Air Pollutants, Radioactive analysis, Crops, Agricultural chemistry, Tritium analysis
- Abstract
The mean expected value of the OBT/HTO ratio (i.e. generic ratio) is derived in this study on the joint basis of a long-term study conducted at Atomic Energy of Canada Limited (AECL)'s Chalk River Laboratories (CRL), model simulations targeted at filling gaps in a yet incomplete timeline of CRL measurements and a reference dataset comprised of numerous experiments reported in the literature. Cultivar variability and disparity in site-specific settings are covered by the reference dataset. Dynamical variability caused by meteorology has been a specific target of the long-term experimental campaign at CRL, where the former two types of variability were eliminated. The distribution of OBT/HTO ratios observed at CRL appears to be a fairly good match to the distribution of OBT/HTO ratios from the literature. This implies that dynamical variability appears important in both cases. Dynamics of atmospheric HTO at CRL is comprised of a sequence of episodes of atmospheric HTO uptake and re-emission of plant HTO. The OBT/HTO ratio appears sensitive to the proportion of the duration of these two episodes: the lesser the frequency (and duration) of plume arrivals, the higher the expected mean OBT/HTO ratio. With the plume arrival frequency defined by the typical wind rose, one would encounter a mean OBT/HTO ratio close to 2. It is important to note that this number is seen both in the reference dataset, and in the continuous timeline of HTO and OBT reconstructed from CRL observations by dynamical interpolation (modelling). Many datasets (including that of CRL) targeted at the OBT/HTO ratio are biased high compared to the suggested number. This could be explained by scarce measurements of the low OBT/HTO ratios in the short phase of uptake of atmospheric HTO by the plant., (Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2014
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31. Current understanding of organically bound tritium (OBT) in the environment.
- Author
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Kim SB, Baglan N, and Davis PA
- Subjects
- Radiation Monitoring, Tritium analysis
- Abstract
It has become increasingly recognized that organically bound tritium (OBT) is the more significant tritium fraction with respect to understanding tritium behaviour in the environment. There are many different terms associated with OBT; such as total OBT, exchangeable OBT, non-exchangeable OBT, soluble OBT, insoluble OBT, tritiated organics, and buried tritium, etc. A simple classification is required to clarify understanding within the tritium research community. Unlike for tritiated water (HTO), the environmental quantification and behaviour of OBT are not well known. Tritiated water cannot bio-accumulate in the environment. However, it is not clear whether or not this is the case for OBT. Even though OBT can be detected in terrestrial biological materials, aquatic biological materials and soil samples, its behaviour is still in question. In order to evaluate the radiation dose from OBT accurately, further study will be required to understand OBT measurements and determine OBT fate in the environment. The relationship between OBT speciation and the OBT/HTO ratio in environmental samples will be useful in this regard, providing information on the previous tritium exposure conditions in the environment and the current tritium dynamics., (Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2013
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32. Field measurements of key parameters associated with nocturnal OBT formation in vegetables grown under Canadian conditions.
- Author
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Kim SB, Workman WG, Korolevych V, and Davis PA
- Subjects
- Air Pollutants, Radioactive metabolism, Canada, Fruit growth & development, Fruit metabolism, Photosynthesis, Plant Leaves growth & development, Plant Leaves metabolism, Plant Leaves radiation effects, Time Factors, Tritium metabolism, Vegetables growth & development, Vegetables metabolism, Air Pollutants, Radioactive toxicity, Atmosphere chemistry, Fruit radiation effects, Tritium toxicity, Vegetables radiation effects
- Abstract
The objective of this study was to provide the parameter values required to model OBT formation in the edible parts of plants following a hypothetical accidental tritium release to the atmosphere at night. The parameters considered were leaf area index, stomatal resistance, photosynthesis rate, the photosynthetic production rate of starch, the nocturnal hydrolysis rate of starch, the fraction of starch produced daily by photosynthesis that appears in the fruits, and the mass of the fruit. Values of these parameters were obtained in the summer of 2002 for lettuce, radishes and tomatoes grown under typical Canadian environmental conditions. Based on the maximum observed photosynthetic rate and growth rate, the fraction of starch translocated to the fruit was calculated to be 17% for tomato fruit and 14% for radish root., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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33. Cinnamon intake lowers fasting blood glucose: meta-analysis.
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Davis PA and Yokoyama W
- Subjects
- Adult, Blood Glucose analysis, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 diet therapy, Diabetes Mellitus, Type 2 physiopathology, Female, Humans, Hyperglycemia etiology, Hypoglycemic Agents chemistry, Male, Oils, Volatile chemistry, Oils, Volatile therapeutic use, Plant Extracts chemistry, Plant Extracts therapeutic use, Plant Preparations chemistry, Plant Stems chemistry, Prediabetic State blood, Prediabetic State diet therapy, Prediabetic State physiopathology, Randomized Controlled Trials as Topic, Cinnamomum zeylanicum chemistry, Hyperglycemia prevention & control, Hypoglycemic Agents therapeutic use, Plant Bark chemistry, Plant Preparations therapeutic use, Spices analysis
- Abstract
Cinnamon, the dry bark and twig of Cinnamomum spp., is a rich botanical source of polyphenolics that has been used for centuries in Chinese medicine and has been shown to affect blood glucose and insulin signaling. Cinnamon's effects on blood glucose have been the subject of many clinical and animal studies; however, the issue of cinnamon intake's effect on fasting blood glucose (FBG) in people with type 2 diabetes and/or prediabetes still remains unclear. A meta-analysis of clinical studies of the effect of cinnamon intake on people with type 2 diabetes and/or prediabetes that included three new clinical trials along with five trials used in previous meta-analyses was done to assess cinnamon's effectiveness in lowering FBG. The eight clinical studies were identified using a literature search (Pub Med and Biosis through May 2010) of randomized, placebo-controlled trials reporting data on cinnamon and/or cinnamon extract and FBG. Comprehensive Meta-Analysis (Biostat Inc., Englewood, NJ, USA) was performed on the identified data for both cinnamon and cinnamon extract intake using a random-effects model that determined the standardized mean difference ([i.e., Change 1(control) - Change 2(cinnamon)] divided by the pooled SD of the post scores). Cinnamon intake, either as whole cinnamon or as cinnamon extract, results in a statistically significant lowering in FBG (-0.49±0.2 mmol/L; n=8, P=.025) and intake of cinnamon extract only also lowered FBG (-0.48 mmol/L±0.17; n=5, P=.008). Thus cinnamon extract and/or cinnamon improves FBG in people with type 2 diabetes or prediabetes.
- Published
- 2011
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34. Carbon-14 transfer into rice plants from a continuous atmospheric source: observations and model predictions.
- Author
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Koarashi J, Davis PA, Galeriu D, Melintescu A, Saito M, Siclet F, and Uchida S
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- Algorithms, Carbon Radioisotopes analysis, Geography, Japan, Models, Theoretical, Air Pollution, Radioactive analysis, Oryza chemistry, Radiation Monitoring methods
- Abstract
Carbon-14 (14C) is one of the most important radionuclides from the perspective of dose estimation due to the nuclear fuel cycle. Ten years of monitoring data on 14C in airborne emissions, in atmospheric CO2 and in rice grain collected around the Tokai reprocessing plant (TRP) showed an insignificant radiological effect of the TRP-derived 14C on the public, but suggested a minor contribution of the TRP-derived 14C to atmospheric 14C concentrations, and an influence on 14C concentrations in rice grain at harvest. This paper also summarizes a modelling exercise (the so-called rice scenario of the IAEA's EMRAS program) in which 14C concentrations in air and rice predicted with various models using information on 14C discharge rates, meteorological conditions and so on were compared with observed concentrations. The modelling results showed that simple Gaussian plume models with different assumptions predict monthly averaged 14C concentrations in air well, even for near-field receptors, and also that specific activity and dynamic models were equally good for the prediction of inter-annual changes in 14C concentrations in rice grain. The scenario, however, offered little opportunity for comparing the predictive capabilities of these two types of models because the scenario involved a near-chronic release to the atmosphere. A scenario based on an episodic release and short-term, time-dependent observations is needed to establish the overall confidence in the predictions of environmental 14C models.
- Published
- 2008
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35. Apple juice consumption reduces plasma low-density lipoprotein oxidation in healthy men and women.
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Hyson D, Studebaker-Hallman D, Davis PA, and Gershwin ME
- Abstract
ABSTRACT Epidemiological studies show that consumption of fruits and vegetables is associated with beneficial effects on human health including reduced risk of coronary artery disease (CAD). Fruits and their juices contain phytochemicals that inhibit in vitro low-density lipoprotein (LDL) oxidation and may account, in part, for their protective effect. However, reports of in vivo antioxidant effects from fruit intake are limited. We conducted a human trial to examine the in vivo effect of consumption of apples (both whole and juice) in an unblinded, randomized, crossover design. Healthy men and women added 375 ml of unsupplemented apple juice or 340 g of cored whole apple to their daily diet for 6 weeks, then crossed over to the alternate product for 6 weeks. Blood samples were obtained at baseline and after each dietary period. Compliance was monitored via biweekly 5-day food records, bodyweight checks, and meetings with study personnel. There were no significant differences between groups in intake of dietary fat, cholesterol, total carbohydrate, sugar, or calories throughout the study. Dietary fiber intake increased by 22% with whole apple consumption. Body weight, fasting serum lipid concentration, and other lipoprotein parameters were unchanged. Apple juice consumption increased ex vivo copper (Cu(++))-mediated LDL oxidation lag time by 20% compared with baseline. Apples and apple juice both reduced conjugated diene formation. Moderate apple juice consumption provides in vivo antioxidant activity. In view of the current understanding of CAD, the observed effect on LDL might be associated with reduced CAD risk and supports the inclusion of apple juice in a healthy human diet.
- Published
- 2000
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36. The analysis of lidar signatures of cirrus clouds.
- Author
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Davis PA
- Abstract
The terminology of light scattering pertinent to a simple form of the lidar equation and the approximate analytical solution of the lidar equation are reviewed without specific restriction on the nature of the cloud scatterers. A boundary value of the volume backscattering coefficient and the relationship between extinction and backscattering are required for the solution. Given the boundary value of the backscattering coefficient and the total transmittance through a cloud, it is possible to derive (by successive approximation) an extinction/ backscatter ratio empirically. Application of the method to the ruby lidar return from a cirrus cloud led to a ratio of 28 sr, and to reasonable profiles of the backscatter coefficient and the transmittance through the cloud.
- Published
- 1969
- Full Text
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