instruction:
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.
question:
Context: Ag-dependent activation of IgE-bearing mast cells is a critical first step in immediate hypersensitivity and other allergic responses. Recent studies have revealed Ag-independent effects of monoclonal mouse IgE molecules on mast cell survival and activation. However, no studies have been performed on the effects of polyclonal IgE molecules. Here, we tested whether polyclonal mouse and human IgE molecules affect survival and cytokine production in mast cells.', 'Mast cells were cultured in the presence of polyclonal mouse and human IgE molecules, and cell survival and cytokine production were analyzed.', 'Polyclonal mouse IgE molecules in sera from mice with atopic dermatitis-like allergic skin inflammation, enhanced survival and cytokine production in mast cell cultures. Similar to the effects of monoclonal IgE, the polyclonal IgE effects were mediated by the high-affinity IgE receptor, FcepsilonRI. Human polyclonal IgE molecules present in sera from atopic dermatitis patients were also capable of activating mast cells, and inducing IL-8 production in human cord blood-derived mast cells.\Question: Does polyclonal IgE induce mast cell survival and cytokine production?
answer:
These results imply that polyclonal IgE in atopic dermatitis and other atopic conditions might modulate mast cell number and function, thus amplifying the allergic response.


question:
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?
answer:
These findings provide impetus for further studies aimed at elucidating the effects of cromolyn and the role of mast cells in pulmonary allotransplantation.


question:
Context: Impaired endothelial function, as assessed by brachial artery flow-mediated dilation (FMD), is an established risk factor for cardiovascular events. FMD is impaired in heart failure (HF) patients, but less is known about hyperemic brachial artery flow. We investigated the relationship between FMD and hyperemic flow with adverse clinical outcomes in HF patients.', 'Brachial artery FMD and hyperemic flow were assessed in 156 patients (70.5 % Male; 45.5% Caucasian; mean age (± SD) = 56.2 (±12.4) years) with HF and reduced left ventricular ejection fraction (LVEF). Cox proportional hazard models were used to assess the potential explanatory association of FMD and hyperemic flow with the composite outcome of death or cardiovascular hospitalization over a median 5-year follow-up period.', 'Both FMD and hyperemic flow were negatively correlated with age, but unrelated to sex, race, body mass index, LVEF or N-terminal pro-B-Type natriuretic peptide (NT-ProBNP). Reduced hyperemic flow, but not FMD, was associated with an increased risk of death or cardiac hospitalization after controlling for traditional risk factors.\Question: Is reactive hyperemia associated with adverse clinical outcomes in heart failure?
answer:

The association of reduced hyperemic flow with increased risk of adverse clinical outcomes suggests that micro-vascular function may be an important prognostic marker in patients with HF.