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Wolff RK. Inhalation Pharmacodynamics. J Aerosol Med Pulm Drug Deliv 2023; 36:275-280. [PMID: 37851976 DOI: 10.1089/jamp.2023.29092.rkw] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023] Open
Abstract
Pharmacodynamics (PD) is discussed in relation to inhalation exposure to inhaled pharmaceutical and toxic agents. Clearly PD is closely related to pharmacokinetics, and this relation is illustrated with reference to inhaled insulin. PD can be related to pharmacologic responses, and some examples are cited. However, PD can also be thought of as the improvement or deterioration in lung disease state. Some of the major PD endpoints, including histopathology, pulmonary function, and bronchoalveolar lavage are reviewed. Brief reference is also given to other specialty biomarkers of PD response.
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Affiliation(s)
- Ronald K Wolff
- RK Wolff Safety Consulting, Inc., Fort Myers, Florida, USA
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Böger R, Hannemann J. Dual role of the L-arginine-ADMA-NO pathway in systemic hypoxic vasodilation and pulmonary hypoxic vasoconstriction. Pulm Circ 2020; 10:2045894020918850. [PMID: 32313645 PMCID: PMC7153195 DOI: 10.1177/2045894020918850] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 03/20/2020] [Indexed: 02/06/2023] Open
Abstract
In healthy vascular endothelium, nitric oxide acts as a vasodilator paracrine mediator on adjacent smooth muscle cells. By activating soluble guanylyl cyclase, nitric oxide stimulates cyclic guanosine monophosphate (cGMP) which causes relaxation of vascular smooth muscle (vasodilation) and inhibition of platelet aggregation. This mechanism is active in both, the systemic and pulmonary circulation. In the systemic circulation, hypoxia results in local vasodilation, which has been shown to be brought about by stabilization of hypoxia-inducible factor-1α (HIF1α) and concomitant upregulation of endothelial nitric oxide synthase. By contrast, the physiological response to hypoxia in the pulmonary circulation is vasoconstriction. Hypoxia in the lung primarily results from hypoventilation of circumscript areas of the lung, e.g. by bronchial tree obstruction or inflammatory infiltration. Therefore, hypoxic pulmonary vasoconstriction is a mechanism preventing distribution of blood to hypoventilated areas of the lungs, thereby maintaining maximal oxygenation of blood. The exact molecular mechanism of hypoxic pulmonary vasoconstriction is less well understood than hypoxic vasodilation in the systemic circulation. While alveolar epithelial cells may be key in sensing low oxygen concentration, and pulmonary vascular smooth muscle cells obviously are the effectors of vasoconstriction, the pulmonary vascular endothelium plays a crucial role as an intermediate between these cell types. Indeed, dysfunctional endothelial nitric oxide release was observed in humans exposed to acute hypoxia, and animal studies suggest that hypoxic pulmonary vasoconstriction is enhanced by nitric oxide synthase inhibition. This may be caused, in part, by elevation of asymmetric dimethylarginine, an endogenous inhibitor of nitric oxide synthesis. High asymmetric dimethylarginine levels are associated with endothelial dysfunction, vascular disease, and hypertension.
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Affiliation(s)
- Rainer Böger
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany
| | - Juliane Hannemann
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany
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Harnan SE, Essat M, Gomersall T, Tappenden P, Pavord I, Everard M, Lawson R. Exhaled nitric oxide in the diagnosis of asthma in adults: a systematic review. Clin Exp Allergy 2017; 47:410-429. [PMID: 27906490 DOI: 10.1111/cea.12867] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 10/24/2016] [Accepted: 11/01/2016] [Indexed: 01/05/2023]
Abstract
OBJECTIVES To identify and synthesize evidence on the diagnostic accuracy of FE NO for asthma in adults. MATERIALS AND METHODS Systematic searches (nine key biomedical databases and trial registers) were carried out on November 2014. Records were included if they recruited patients with the symptoms of asthma; used a single set of inclusion criteria; measured FE NO50 in accordance with American Thoracic Society guidelines, 2005 (off-line excluded); reported/allowed calculation of true-positive, true-negative, false-positive and false-negative patients as classified against any reference standard. Study quality was assessed using QUADAS II. Meta-analysis was planned where clinical study heterogeneity allowed. Rule-in and rule-out uses of FE NO were considered. RESULTS A total of 4861 records were identified originally and 1312 in an update. Twenty-seven studies were included. Heterogeneity precluded meta-analysis. Results varied even within subgroups of studies. Cut-off values for the best sum of sensitivity and specificity varied from 12 to 55 p.p.b., but did not produce high accuracy. 100% sensitivity or 100% specificity was reported by some studies indicating potential use as a rule-in or rule-out strategy. CONCLUSIONS AND CLINICAL RELEVANCE FE NO50 had variable diagnostic accuracy even within subgroups of studies with similar characteristics. Diagnostic accuracy, optimal cut-off values and best position for FE NO50 within a pathway remain poorly evidenced.
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Affiliation(s)
- S E Harnan
- Health Economics and Decision Science, ScHARR, University of Sheffield, Sheffield, UK
| | - M Essat
- Health Economics and Decision Science, ScHARR, University of Sheffield, Sheffield, UK
| | - T Gomersall
- Health Economics and Decision Science, ScHARR, University of Sheffield, Sheffield, UK
| | - P Tappenden
- Health Economics and Decision Science, ScHARR, University of Sheffield, Sheffield, UK
| | - I Pavord
- Respiratory Medicine Unit, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - M Everard
- School of Paediatrics & Child Health, Princess Margaret Hospital, University of Western Australia, Crawley, WA, Australia
| | - R Lawson
- Department of Respiratory Medicine, Royal Hallamshire Hospital, Sheffield, UK
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Hypoxia-inducible factor-1α inhibition modulates airway hyperresponsiveness and nitric oxide levels in a BALB/c mouse model of asthma. Clin Immunol 2017; 176:94-99. [PMID: 28093362 DOI: 10.1016/j.clim.2017.01.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 12/18/2022]
Abstract
Hypoxia-inducible factor (HIF)-1α is a master regulator of inflammation and is upregulated in alveolar macrophages and lung parenchyma in asthma. HIF-1α regulates select pathways in allergic inflammation, and thus may drive particular asthma phenotypes. This work examines the role of pharmacologic HIF-1α inhibition in allergic inflammatory airway disease (AIAD) pathogenesis in BALB/c mice, which develop an airway hyperresponsiveness (AHR) asthma phenotype. Systemic treatment with HIF-1α antagonist YC-1 suppressed the increase in HIF-1α expression seen in control AIAD mice. Treatment with YC-1 also decreased AHR, blood eosinophilia, and allergic inflammatory gene expression: IL-5, IL-13, myeloperoxidase and iNOS. AIAD mice had elevated BAL levels of NO, and treatment with YC-1 eliminated this response. However, YC-1 did not decrease BAL, lung or bone marrow eosinophilia. We conclude that HIF-1α inhibition in different genetic backgrounds, and thus different AIAD phenotypes, decreases airway resistance and markers of inflammation in a background specific manner. CAPSULE SUMMARY Asthma is a common disease that can be difficult to control with current therapeutics. We describe how pharmacologic targeting of a specific transcription factor, HIF-1α, suppresses asthmatic airway reactivity and inflammation.
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Guo Z, Wang Y, Xing G, Wang X. Diagnostic accuracy of fractional exhaled nitric oxide in asthma: a systematic review and meta-analysis of prospective studies. J Asthma 2016; 53:404-12. [PMID: 26796787 DOI: 10.3109/02770903.2015.1101132] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND Fractional exhaled nitric oxide (FeNO) has been proposed as a non-invasive measure of airway inflammation in asthma. However, its accuracy for the diagnosis of asthma in different populations is not completely clear. The aim of this study was to investigate the accuracy of FeNO measurement for the diagnosis of asthma through a systematic review and meta-analysis of prospective studies. METHODS A systematic search current to July 2014 was performed in Pubmed, EMBASE, Medline, the Cochrane databases, CNKI, Wanfang and Weipu to find relevant studies. All prospective studies on the use of FeNO for the diagnosis of asthma were included. RESULTS Twenty-five studies including 3983 subjects were analyzed. The pooled sensitivity, specificity and diagnostic odds ratio (DOR) for the entire population was 72% (95% CI, 70-74%), 78% (95% CI, 76-80%) and 15.92 (95% CI, 10.70-23.68), respectively. The area under the summary receiver operating characteristic (sROC) curves revealed a receiver-operating characteristic of 0.88. In subgroup analysis, the DOR for patients using corticosteroids, as well as those for steroid-naïve, non-smoking, smoking, chronic cough and allergic rhinitis patients were 4.47 (95% CI, 3.39-5.90), 21.40 (95% CI, 15.38-29.76), 19.84 (95% CI, 15.63-25.19), 5.41 (95% CI, 2.97-9.86), 35.36 (95% CI, 23.90-52.29), and 2.99 (95% CI, 0.85-10.45), respectively. CONCLUSION FeNO is accurate for the diagnosis of asthma in steroid-naive or non-smoking patients, particularly in chronic cough patients.
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Affiliation(s)
- Zhi Guo
- a Department of Pulmonary Diseases , Jinan Military General Hospital , Jinan , Shandong , China
| | - Ying Wang
- a Department of Pulmonary Diseases , Jinan Military General Hospital , Jinan , Shandong , China
| | - Guohong Xing
- a Department of Pulmonary Diseases , Jinan Military General Hospital , Jinan , Shandong , China
| | - Xin Wang
- a Department of Pulmonary Diseases , Jinan Military General Hospital , Jinan , Shandong , China
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Lin J, Yin K, Su N, Huang M, Qiu C, Liu C, Cai S, Hao C. Chinese expert consensus on clinical use of non-invasive airway inflammation assessment in bronchial asthma. ANNALS OF TRANSLATIONAL MEDICINE 2015; 3:302. [PMID: 26697462 PMCID: PMC4669313 DOI: 10.3978/j.issn.2305-5839.2015.11.31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 11/17/2015] [Indexed: 02/05/2023]
Affiliation(s)
| | | | | | | | | | | | | | | | - on behalf of the Chinese Society of Chest Physicians
- China-Japan Friendship Hospital, Beijing 100029, China; The First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China; Shenzhen People’s Hospital, Shenzhen 518020, China; West China Hospital, Sichuan University, Chengdu 610041, China; Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Soochow University Affiliated Children’s Hospital, Suzhou 215003, China
| | - Chinese Medical Doctor Association
- China-Japan Friendship Hospital, Beijing 100029, China; The First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China; Shenzhen People’s Hospital, Shenzhen 518020, China; West China Hospital, Sichuan University, Chengdu 610041, China; Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Soochow University Affiliated Children’s Hospital, Suzhou 215003, China
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Lin J, Yin K, Su N, Huang M, Qiu C, Liu C, Cai S, Hao C. Chinese expert consensus on clinical use of non-invasive airway inflammation assessment in bronchial asthma. J Thorac Dis 2015; 7:2061-78. [PMID: 26716047 PMCID: PMC4669291 DOI: 10.3978/j.issn.2072-1439.2015.11.51] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 11/17/2015] [Indexed: 02/05/2023]
Affiliation(s)
| | | | | | | | | | | | | | | | - on behalf of the Chinese Society of Chest Physicians
- China-Japan Friendship Hospital, Beijing 100029, China; The First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China; Shenzhen People’s Hospital, Shenzhen 518020, China; West China Hospital, Sichuan University, Chengdu 610041, China; Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Soochow University Affiliated Children’s Hospital, Suzhou 215003, China
| | - Chinese Medical Doctor Association
- China-Japan Friendship Hospital, Beijing 100029, China; The First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, China; Shenzhen People’s Hospital, Shenzhen 518020, China; West China Hospital, Sichuan University, Chengdu 610041, China; Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Soochow University Affiliated Children’s Hospital, Suzhou 215003, China
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Song WJ, Kwon JW, Kim EJ, Lee SM, Kim SH, Lee SY, Kim SH, Park HW, Chang YS, Kim WK, Shim JY, Seo JH, Kim BJ, Kim HB, Song DJ, Jang GC, Jang AS, Park JW, Yoon HJ, Lee JS, Cho SH, Hong SJ. Clinical application of exhaled nitric oxide measurements in a korean population. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2014; 7:3-13. [PMID: 25553257 PMCID: PMC4274466 DOI: 10.4168/aair.2015.7.1.3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 10/25/2013] [Indexed: 12/31/2022]
Abstract
Nitric oxide (NO) is a biologic mediator of various physiologic functions. Recent evidence suggests the clinical utility of fractional exhaled NO (FeNO) as a biomarker for assessing asthma and other respiratory diseases. FeNO methodologies have been recently standardized by international research groups and subsequently validated in several Korean population studies. Normal ranges for FeNO have been reported for various ethnic groups, and the clinical utility has been widely evaluated in asthma and various respiratory diseases. Based on current evidence including most of Korean population data, this position paper aims to introduce the methodological considerations, and provide the guidance for the proper clinical application of FeNO measurements in Korean populations.
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Affiliation(s)
- Woo-Jung Song
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Ji-Won Kwon
- Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Eun-Jin Kim
- Allergy TF, Department of Immunology and Pathology, Korea National Institute of Health, Cheongwon, Korea
| | - Sang-Min Lee
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea
| | - Sae-Hoon Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - So-Yeon Lee
- Department of Pediatrics, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Suwon, Korea
| | - Sang-Heon Kim
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea
| | - Heung-Woo Park
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Yoon-Seok Chang
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea. ; Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Woo Kyung Kim
- Department of Pediatrics, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Jung Yeon Shim
- Department of Pediatrics, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Ju-Hee Seo
- Department of Pediatrics, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Byoung-Ju Kim
- Department of Pediatrics, Korea Cancer Center Hospital, Seoul, Korea
| | - Hyo Bin Kim
- Department of Pediatrics, Hae-undae Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Dae Jin Song
- Department of Pediatrics, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea
| | - Gwang Cheon Jang
- Department of Pediatrics, National Health Insurance Corporation Ilsan Hospital, Goyang, Korea
| | - An-Soo Jang
- Department of Internal Medicine, Soonchunhyang University College of Medicine, Seoul, Korea
| | - Jung-Won Park
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Ho-Joo Yoon
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea
| | - Joo-Shil Lee
- Allergy TF, Department of Immunology and Pathology, Korea National Institute of Health, Cheongwon, Korea
| | - Sang-Heon Cho
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Soo-Jong Hong
- Department of Pediatrics, Childhood Asthma Atopy Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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Koehler C, Thielen S, Ginzkey C, Hackenberg S, Scherzed A, Burghartz M, Paulus M, Hagen R, Kleinsasser NH. Nitrogen dioxide is genotoxic in urban concentrations. Inhal Toxicol 2013; 25:341-7. [PMID: 23701639 DOI: 10.3109/08958378.2013.788104] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In the discussion on toxic and genotoxic thresholds of air pollutants such as nitrogen dioxide (NO2), realistically low urban concentration ranges are of major interest. For NO2, the WHO defines the annual limit value as corresponding to 0.02 ppm. In the present study, the toxicity and genotoxicity of NO2 is set at a concentration under this limit value and examined in human nasal epithelium at different exposure durations in vitro. Nasal epithelial mucosa samples of 10 donors were harvested during nasal air passage surgery and cultured as an air-liquid interface. Exposure to 0.01 ppm NO2 or synthetic air as a control was performed for 0.5, 1, 2 and 3 h. Analysis included the caspase-3 ELISA, the single cell microgel electrophoresis (comet) assay and the micronucleus assay. The caspase-3 activity was not influenced by NO2 exposure, DNA strand fragmentation correlated with exposure durations to NO2 at 0.01 ppm NO2, and no cytotoxic effects such as apoptosis, necrosis or disturbances of cell proliferation were present. However, micronucleus induction as a sign of genotoxicity at an exposure duration of 3 h could be shown. Shorter exposures did not induce micronucleus formation. In summary, genotoxicity of NO2 could be demonstrated at a common urban concentration in vitro, but a threshold of NO2 genotoxicity could not be defined based on the present experiments.
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Affiliation(s)
- Christian Koehler
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University Hospital of Wuerzburg, Wuerzburg, Germany
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Crotty Alexander LE, Akong-Moore K, Feldstein S, Johansson P, Nguyen A, McEachern EK, Nicatia S, Cowburn AS, Olson J, Cho JY, Isaacs H, Johnson RS, Broide DH, Nizet V. Myeloid cell HIF-1α regulates asthma airway resistance and eosinophil function. J Mol Med (Berl) 2013; 91:637-44. [PMID: 23250618 PMCID: PMC3646920 DOI: 10.1007/s00109-012-0986-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 11/09/2012] [Accepted: 12/02/2012] [Indexed: 01/10/2023]
Abstract
Hypoxia-inducible factor (HIF)-1α is a master regulator of inflammatory activities of myeloid cells, including neutrophils and macrophages. These studies examine the role of myeloid cell HIF-1α in regulating asthma induction and pathogenesis, and for the first time, evaluate the roles of HIF-1α and HIF-2α in the chemotactic properties of eosinophils, the myeloid cells most associated with asthma. Wild-type (WT) and myeloid cell-specific HIF-1α knockout (KO) C57BL/6 mice were studied in an ovalbumin (OVA) model of asthma. Administration of the pharmacological HIF-1α antagonist YC-1 was used to corroborate findings from the genetic model. WT, HIF-1α, and HIF-2α KO eosinophils underwent in vitro chemotaxis assays. We found that deletion of HIF-1α in myeloid cells and systemic treatment with YC-1 during asthma induction decreased airway hyperresponsiveness (AHR). Deletion of HIF-1α in myeloid cells in OVA-induced asthma also reduced eosinophil infiltration, goblet cell hyperplasia, and levels of cytokines IL-4, IL-5, and IL-13 in the lung. HIF-1α inhibition with YC-1 during asthma induction decreased eosinophilia in bronchoalveolar lavage, lung parenchyma, and blood, as well as decreased total lung inflammation, IL-5, and serum OVA-specific IgE levels. Deletion of HIF-1α in eosinophils decreased their chemotaxis, while deletion of the isoform HIF-2α led to increased chemotaxis. This work demonstrates that HIF-1α in myeloid cells plays a role in asthma pathogenesis, particularly in AHR development. Additionally, treatment with HIF-1α inhibitors during asthma induction decreases AHR and eosinophilia. Finally, we show that HIF-1α and HIF-2α regulate eosinophil migration in opposing ways.
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Affiliation(s)
- Laura E Crotty Alexander
- Pulmonary Critical Care Section, Veterans Affairs San Diego Healthcare System, La Jolla, CA, USA.
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11
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Bronchiolitis obliterans after allogeneic hematopoietic SCT: further insight—new perspectives? Bone Marrow Transplant 2013; 48:1224-9. [DOI: 10.1038/bmt.2013.17] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 01/16/2013] [Accepted: 01/23/2013] [Indexed: 01/11/2023]
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Davis BE, Cockcroft DW. Past, present and future uses of methacholine testing. Expert Rev Respir Med 2012; 6:321-9. [PMID: 22788946 DOI: 10.1586/ers.12.29] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Methacholine challenge testing is a valuable diagnostic and research tool used by clinicians to assist in the diagnosis of asthma, and by researchers to understand disease pathophysiology and assess novel therapeutic efficacy. The use of methacholine challenge in asthma relates to its direct effect on airway smooth muscle (i.e., bronchoconstriction) as a measure of airway hyperresponsiveness, a cardinal feature of asthma. Airway hyperresponsiveness has been documented in other airway disorders, including chronic obstructive pulmonary disease, cystic fibrosis and allergic rhinitis; however, there is little clinical application of methacholine challenge in these conditions as a diagnostic or disease management tool. The authors will review the aspects of methacholine challenge testing, as they relate to asthma, and point out its usefulness in clinical research. A brief review of past (historical) uses and speculation as to the future uses of methacholine challenge will also be discussed.
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Affiliation(s)
- Beth E Davis
- Department of Medicine, Division of Respirology, Critical Care and Sleep Medicine, Royal University Hospital, University of Saskatchewan, 103 Hospital Drive, Saskatoon, SK, S7N 0W8, Canada.
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de la Riva-Velasco E, Krishnan S, Dozor AJ. Relationship between exhaled nitric oxide and exposure to low-level environmental tobacco smoke in children with asthma on inhaled corticosteroids. J Asthma 2012; 49:673-8. [PMID: 22799435 DOI: 10.3109/02770903.2012.701363] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES The relationship between exhaled nitric oxide (FeNO) and asthma severity or control is inconsistent. Active smoking lowers FeNO, but the relationship between passive smoking and FeNO is less clear. Children may be exposed to low-level environmental tobacco smoke (ETS) or thirdhand smoke, even if parents avoid smoking in the presence of their children. Our hypothesis was that FeNO is lower in children with asthma exposed to low-level ETS when compared with those who are not exposed. METHODS Children with stable asthma, 8-18 years of age, on low- or medium-dose inhaled corticosteroids (ICS) were enrolled. Spirometry, Asthma Control Questionnaire (ACQ), FeNO, exhaled breath condensate pH (EBC pH), and EBC ammonia were compared between children with and without ETS exposure as determined by urinary cotinine. RESULTS Thirty-three subjects were enrolled, of which 10 (30%) had urinary cotinine levels ≥1 ng/ml. There were no significant differences between the two groups in age, sex, BMI percentile, atopy status, FEV(1), EBC pH, or EBC ammonia. Median ACQ was 0.29 (IQR: 0.22-0.57) for those with cotinine levels <1 ng/ml and 0.64 (IQR: 0.57-1.1) for those with cotinine levels of ≥1 ng/ml, p = .02. Median FeNO (ppb) was 23.9 (IQR: 15.2-34.5) for unexposed subjects and 9.6 (IQR: 5.1-15.8) for exposed subjects, p = .008. CONCLUSIONS Children with asthma on low to medium doses of ICS and recent low-level ETS exposure have lower FeNO levels when compared with non-ETS-exposed subjects. Exposure to low-level ETS or thirdhand smoke may be an important variable to consider when interpreting FeNO as a biomarker for airway inflammation.
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Affiliation(s)
- Elizabeth de la Riva-Velasco
- Division of Pediatric Pulmonology, Department of Pediatrics, Maria Fareri Children's Hospital at Westchester Medical Center and New York Medical College, Valhalla, NY 10595, USA.
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Nair P, Dasgupta A, Brightling CE, Chung KF. How to diagnose and phenotype asthma. Clin Chest Med 2012; 33:445-57. [PMID: 22929094 DOI: 10.1016/j.ccm.2012.05.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Asthma has been described as a chronic disease of the airways characterized by variable airflow obstruction, airway hyperresponsiveness, and airway inflammation. This review discusses the diagnosis and phenotyping of asthma, with a special emphasis on phenotyping based on the nature of cellular inflammation and radiological imaging and how this could be used to direct the treatment of asthma and, in the future, to apply specifically directed therapies to specific phenotypes.
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Affiliation(s)
- Parameswaran Nair
- Department of Medicine, St Joseph's Healthcare, McMaster University, 50 Charlton Avenue East, Hamilton, Ontario L8N4A6, Canada.
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