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: Symptomatic patients with severe aortic stenosis (AS) demonstrate abnormal left ventricular (LV) mechanics. The aim of this study was to compare mechanics in asymptomatic and symptomatic patients with severe AS using two-dimensional myocardial strain imaging.', 'One hundred fifty-four patients with severe AS (aortic valve area ≤ 1.0 cm(2)) referred to a heart valve clinic from 2004 to 2011 were studied. Thirty patients were asymptomatic, with normal LV ejection fractions (≥ 55%), without other significant valvular disease or wall motion abnormalities. Thirty-two symptomatic patients who underwent early aortic valve replacement, with similar age, gender, LV ejection fraction, and aortic valve area, were selected for comparison. Both groups were also compared with 32 healthy subjects with similar age and gender distributions and normal echocardiographic results who served as controls. LV longitudinal and circumferential strain and rotation were measured using speckle-tracking software applied to archived echocardiographic studies. Conventional echocardiographic and myocardial mechanical parameters were compared among the study subgroups.', 'Patients with asymptomatic severe AS demonstrated smaller reductions in longitudinal strain, higher (supernormal) apical circumferential strain (-38 ± 6% vs -35 ± 4%, P < .05), and extreme (supernormal) apical rotation (12.2 ± 4.9° vs 2.9 ± 1.7°, P < .0005) compared with symptomatic patients. Apical rotation < 6° was the single significant predictor of symptoms in logistic regression analysis of clinical, echocardiographic, and mechanical parameters. Twelve asymptomatic patients underwent eventual aortic valve replacement and showed decreases in strain and apical rotation compared with baseline values.\Question: Are symptoms in severe aortic stenosis associated with decreased compensatory circumferential myocardial mechanics?
[EX A]: Longitudinal strain was uniformly low in patients with severe AS and lower in those with symptoms. Compensatory circumferential myocardial mechanics (increased apical circumferential strain and rotation) were absent in symptomatic patients. Thus, myocardial mechanics may help in the follow-up of patients with severe AS and timing of valve surgery.

[EX Q]: Context: Allogeneic mesenchymal stem cells (MSCs) exhibit therapeutic effects in human autoimmune diseases such as systemic lupus erythematosus (SLE), but the underlying mechanisms remain largely unknown. The aim of this study was to investigate how allogeneic MSCs mediate immunosuppression in lupus patients.', 'The effects of allogeneic umbilical cord-derived MSCs (UC-MSCs) on inhibition of T cell proliferation were determined. MSC functional molecules were stimulated with peripheral blood mononuclear cells from healthy controls and SLE patients and examined by real-time polymerase chain reaction. CD4+ and CD8+ T cells were purified using microbeads to stimulate MSCs in order to determine cytokine expression by MSCs and to further determine which cell subset(s) or which molecule(s) is involved in inhibition of MSC-mediated T cell proliferation. The related signaling pathways were assessed. We determined levels of serum cytokines in lupus patients before and after UC-MSC transplantation.', 'Allogeneic UC-MSCs suppressed T cell proliferation in lupus patients by secreting large amounts of indoleamine 2,3-dioxygenase (IDO). We further found that interferon-γ (IFNγ), which is produced predominantly by lupus CD8+ T cells, is the key factor that enhances IDO activity in allogeneic MSCs and that it is associated with IFNGR1/JAK-2/STAT signaling pathways. Intriguingly, bone marrow-derived MSCs from patients with active lupus demonstrated defective IDO production in response to IFNγ and allogeneic CD8+ T cell stimulation. After allogeneic UC-MSC transplantation, serum IDO activity increased in lupus patients.\Question: Is a CD8 T cell/indoleamine 2,3-dioxygenase axis required for mesenchymal stem cell suppression of human systemic lupus erythematosus?
[EX A]: We found a previously unrecognized CD8+ T cell/IFNγ/IDO axis that mediates the therapeutic effects of allogeneic MSCs in lupus patients.

[EX Q]: Context: This study aimed to investigate the interaction between gender and other socio-economic characteristics on sleep quality of the patients with Coronary Artery Disease (CAD).', 'This cross sectional study was conducted on 717 patients with CAD. The socio- economic status (education level, income, marital status, and place of residence) was considered as the independent variable. Besides, the study outcome was the quality of sleep which was measured using Pittsburgh Sleep Quality Index (PSQI). Gender was considered as a possible effect modifier. Two-way ANOVA was used to evaluate the interaction between gender and socio-economic factors on sleep quality. As defined by Baron and Kenny, moderator was defined as a variable that affected the direction or magnitude of the association of interest.', 'Female gender, low education level, and low income were predictive of poor sleep quality. Among female (10.0 ± 4.3 vs. 7.6 ± 5.0, P < 0.05), but not male patients (6.7 ± 4.2 vs. 7.0 ± 4.2, P > 0.05), low education was associated with poor sleep quality. Also, among female (10.0 ± 4.3 vs. 5.7 ± 2.5, P < 0.05), but not male patients (7.0 ± 4.2 vs. 6.0 ± 3.8, P > 0.05), low income was predictive of poor sleep quality. Gender did not modify the effect of other socio-economic factors on sleep quality.\Question: Does gender modify the effects of education and income on sleep quality of the patients with coronary artery disease?
[EX A]:
Among female but not male patients with CAD, low education and income were associated with poor sleep quality. This information helps us better understand the mechanisms behind the poor sleep quality of the female patients with CAD. This is important because poor sleep is a prognostic factor among the CAD patients.