Ion and fluid transport properties of small airways in cystic fibrosis

Rationale: Small airways constitute amajor site of pathology in cystic fibrosis (CF) and provide most of the surface area of the conducting airways of the lung. Little is known, however, about the impact of CF on ion and fluid transport in small (bronchiolar) airways. Objectives: To describe the ion and fluid transport properties of CF bronchiolar epithelium. Methods: Primary cultures of human bronchial and bronchiolar (non-CF and CF) epithelial cells were obtained. The bioelectric properties were studied in Ussing chambers and the airway surface liquid (ASL) height was measured with confocal microscopy. Main Results: Primary cultures of ΔF508 CF bronchiolar epithelial cells displayed higher transepithelial resistance than non-CF cultures, whereas baseline short circuit current and amiloride-inhibitable short circuit current were similar in both preparations. The ASL height was significantly smaller in CF compared with non-CF preparations. In the presence of amiloride, addition of forskolin increased short circuit current in non-CF but not in CF bronchiolar cultures, and the ATP-induced increase in short circuit current was lower in CF than in non-CF cultures. Non-CF bronchiolar preparations displayed larger short circuit current and fluid secretion in responses to forskolin than non-CF bronchial preparations, suggesting that CFTR-dependent Cl- transport may play a more important role in the regulation of fluid transport in small airways than in large airways. Conclusion: In CF small airways, defective Cl- secretion combined with unregulated (persistent) Na+ absorption results in ASLdepletion

Hemoglobin Roseau-Pointe a Pitre α2β290 (F6) Glu → Gly: a new hemoglobin variant with slight instability and low oxygen affinity

AbstractA Dominican neonate carrying a new abnormal hemoglobin, hemoglobin Roseau Pointe-à-Pitre α2β290 (F6) Glu → Gly, was detected in Guadeloupe during application of a cord blood screening program. This variant behaved in isoelectrofocusing as an Hb D, and displayed instability and low whole blood oxygen affinity. In the affected family it was present, either isolated, or in association with a β+ thalassemia trait

Large-Scale Production of Microcrystals and Precipitates of Proteins and Their Complexes

International audienceThe optimum conditions for the formation of plate-like and urchin-like microcrystals of biomolecules and their transfer to rotors for solid-state NMR spectroscopy depend on a variety of factors, of which minimizing the manipulation of the microcrystals and storing the sample for several months at 277 K (4 degrees C) play an important role. Three biological systems were investigated: Hen Egg-White (HEW) lysozyme (129 residues), the lengthened C-terminal domain (LCter) of Human centrin 2 (89 residues), and the complex between the C-terminal domain (Cter) of Human centrin 2 (79 residues) and the P17-XPC peptide (17 residues)