Comer DM, Elborn JS, Ennis M Comparison of nasal and bronchial epithelial cells obtained from patients with COPD. PLoS One. 2012;7(3):e32924. doi: 10.1371/journal.pone.0032924. Epub 2012 Mar 6.
Kistemaker LE, Oenema TA, Meurs H, Gosens R Regulation of airway inflammation and remodeling by muscarinic receptors: perspectives on anticholinergic therapy in asthma and COPD. Life Sci. 2012 Nov 27;91(21-22):1126-33. doi: 10.1016/j.lfs.2012.02.021. Epub 2012 Mar 3. Review.
Perng DW, Tao CW, Su KC, Tsai CC, Liu LY, Lee YC Anti-inflammatory effects of salmeterol/fluticasone, tiotropium/fluticasone or tiotropium in COPD. Eur Respir J. 2009 Apr;33(4):778-84. doi: 10.1183/09031936.00115308. Epub 2009 Jan 7.
Singh D, Edwards L, Tal-Singer R, Rennard S Sputum neutrophils as a biomarker in COPD: findings from the ECLIPSE study. Respir Res. 2010 Jun 15;11:77. doi: 10.1186/1465-9921-11-77.
Wessler I, Kirkpatrick CJ Acetylcholine beyond neurons: the non-neuronal cholinergic system in humans. Br J Pharmacol. 2008 Aug;154(8):1558-71. doi: 10.1038/bjp.2008.185. Epub 2008 May 26. Review.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
