Browse the corpus
Walk the Even Hospital Database by book and chapter — the raw source passages that ground Ask, DDx, and the rest.
1 passage
©2013 UpToDate ® Print Email Nasal potential difference measurements in cystic fibrosis Examples of nasal potential difference tracings in a normal patient (Panel A) and a patient with cystic fibrosis (Panel B). The x-axis is time (min) as described, and the y-axis is nasal potential difference (PD) (mV, upward is polarizing). The normal phenotype includes a lower (less polarized) baseline PD in Solution #1, a small depolarizing change in PD after amiloride perfusion (Solution #2), and a repolarizing PD after perfusion with low-chloride (0 [CI-]) and low-chloride + isoproterenol (Solutions #3 and #4 - continued presence of amiloride). The cystic fibrosis phenotype includes a higher (more polarized) baseline PD, a large depolarizing change in PD after amiloride perfusion, and absent repolarization after perfusion with 0 [CI-] and 0 [CI-] + isoproterenol. ATP-stimulated PD (Solution #5, reflecting stimulation of calcium activated chloride conductance) is retained in normal subjects and in subjects with cystic fibrosis. Reproduced with permission from: Clancy JP, Rowe SM, Bebok Z, et al. No Detectable Improvements in Cystic Fibrosis Transmembrane Conductance Regulator by Nasal Aminoglycosides in Patients with Cystic Fibrosis with Stop Mutations. Am J Respir Cell Mol Biol 2007; 37:59. Official Journal of the American Thoracic Society. Copyright ©2007 American Thoracic Society.