In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[EX Q]: Context: Mast cells have been associated with obliterative bronchiolitis (OB) in human pulmonary allografts, although their role in the development of OB remains unknown.', 'In this study, we evaluated the role of mast cells in pulmonary allograft rejection using an orthotopic rat pulmonary allograft model that utilizes chronic aspiration of gastric fluid to reliably obtain OB. Pulmonary allograft recipients (n = 35) received chronic aspiration of gastric fluid with (n = 10) and without (n = 16) treatment with a mast cell membrane stabilizer, cromolyn sodium, or chronic aspiration with normal saline (n = 9) as a control.', 'The acute graft injury associated with long ischemic time in the model (6 hours total ischemic time; typical acute graft injury rate ~30%) was apparently blocked by cromolyn, because peri-operative mortality associated with the acute graft injury was not observed in any of the animals receiving cromolyn (p = 0.045). Further, the rats receiving cromolyn developed significantly fewer OB lesions than those treated with gastric fluid alone (p < 0.001), with a mean reduction of 46% of the airways affected.\Question: Does cromolyn ameliorate acute and chronic injury in a rat lung transplant model?
[EX A]: These findings provide impetus for further studies aimed at elucidating the effects of cromolyn and the role of mast cells in pulmonary allotransplantation.

[EX Q]: Context: Optimistic people report a higher quality of life, engage in more active coping and adopt more health-promoting behaviors than people low in optimism, ie, pessimism. We evaluated whether pessimists are more likely to show progression in carotid disease than optimists.', 'A total of 209 middle-aged healthy premenopausal women enrolled in an epidemiological study of cardiovascular risk factors and had carotid scans 10.4 years and 13.5 years later when they were at least 5 years postmenopausal. Women completed the Life Orientation Test (LOT), a measure of pessimistic and optimistic attitudes, at study entry and at the time of the first carotid scan. Analyses evaluated the association of LOT scores and change in carotid intima medial thickness (IMT) across 3 years.', 'Multiple linear regression analyses showed that the higher the pessimism scores at study entry, the greater the increase in mean IMT (beta = 0.17, p <.007). A comparison of those in the lowest quartile of LOT scores (most optimistic) with those in the other three quartiles showed that the most optimistic group had less progression than the remaining more pessimistic women (mean percent increase = 1.3 and 6.0 for mean IMT, F = 15.4, p <.001). Women who were chronically optimistic at study entry and at the first carotid scan (bottom quartiles at both times) had less progression in mean IMT than did those who were chronically pessimistic (top quartiles at both times).\Question: Do optimistic attitudes protect against progression of carotid atherosclerosis in healthy middle-aged women?
[EX A]: Optimistic women are less likely to show progression of carotid disease in mid-life than are pessimists.

[EX Q]: Context: To determine whether the cellular physiology of the lens actively maintains the optical properties of the lens and whether inhibition of lens transport affects overall visual quality.', 'One lens from a pair of bovine lenses was cultured in artificial aqueous humor (AAH), while the other was cultured in either AAH-High-K+ or AAH + 0.1 mM ouabain for 4 hours. Lens pairs or whole enucleated eyes were then imaged in 4.7 Tesla (T) high-field small animal magnet. Lens surface curvatures, T1 measurements of water content, and T2 measurements of water/protein ratios were extracted from cultured lenses, while the geometrical parameters that define the optical pathway were obtained from whole eyes. Gradients of refractive index (GRIN), calculated from T2 measurements, and the extracted geometric parameters were inputted into optical models of the isolated lens and the whole bovine eye.', 'Inhibiting circulating fluxes by inhibiting the Na/K-ATPase with ouabain or depolarization of the lens potential by High K+ caused changes to lens water content, the water/protein ratio (GRIN) and surface geometry that manifested as an increase in optical power and a decrease in negative spherical aberration in cultured lenses. Changes to optical properties of the lens resulted in a myopic shift that impaired vision quality in the optical model of the bovine eye.\Question: Does active Maintenance of the Gradient of Refractive Index be Required to Sustain the Optical Properties of the Lens?
[EX A]:
The cellular physiology of the lens actively maintains its optical properties and inhibiting the Na/K/ATPase induces a myopic shift in vision similar to that observed clinically in patients who go on to develop cataract.