Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Q: Apelin has been shown ex vivo to be a potent cardiac inotrope. This study was undertaken to evaluate the in vivo effects of apelin on cardiac function in native and ischemic cardiomyopathic rat hearts using a novel combination of a perivascular flow probe and a conductance catheter.', 'Native rats (n =32) and rats in heart failure 6 weeks after left anterior descending coronary artery ligation (n =22) underwent median sternotomy with placement of a perivascular flow probe around the ascending aorta and a pressure volume conductance catheter into the left ventricle. Compared with sham-operated rats, the ligated rats had significantly decreased baseline Pmax and max dP/dt. Continuous infusion of apelin at a rate of 0.01 microg/min for 20 minutes significantly increased Pmax and max dP/dt compared with infusion of vehicle alone in both native and failing hearts. Apelin infusion increased cardiac contractility, indicated by a significant increase in stroke volume (SV) without a change in left ventricular end diastolic volume (102+/-16% change from initial SV versus 26+/-20% for native animals, and 110+/-30% versus 26+/-11% for ligated animals), as well as an increase in preload recruitable stroke work (180+/-24 mm Hg versus 107+/-9 mm Hg for native animals).

A: Does apelin have in vivo inotropic effects on normal and failing hearts?
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Q: Obstructive sleep apnea (OSA) is a common disorder characterized by chronic intermittent hypoxia (CIH). OSA is prevalent in obese subjects and is associated with endothelial dysfunction and cardiovascular disorders. We tested the hypothesis that the deleterious effects of IH could be further modulated by diet-induced obesity.', 'Thirty adult (8-10 weeks) male C57BL/6J mice were divided into four groups. Mice were subjected to CIH or intermittent air (IA) for 12h a day and fed either a high fat (HF) or a low fat control diet (CD) for 6weeks. We analyzed endothelial function using a wire myograph, and measured markers of oxidative stress (plasma malondialdehyde (MDA) and total antioxidant capacity (TAC)) using colorimetrical assays. We also measured C-reactive protein (CRP) using ELISA and endothelial nitric oxide (eNOS) gene expression using real time PCR.', 'Stimulated endothelial dependent dilation was significantly impaired only in the group fed high fat diet and subjected to CIH (Emax: HFIH 78±2%, p<0.0001) when compared to the other groups (Emax: HFIA 95±0.7%, CDIH 94±2%, CDIA 97±1%). Also basal endothelial dependant dilation was attenuated in the HFIH group compared to the HFIA group (Emax: HFIH: 179±10% vs. HFIA: 149±11% in the presence of L-NAME). Levels of MDA were elevated in the CDIH group when compared to CDIA (0.68±0.04 vs. 0.41±0.03 μM, p<0.05) but were greatest in the HFIH group (0.83±0.08 μM, p<0.05). However, there was no significant increase in MDA levels in the HFIA group (0.45±0.03 μM, p=NS) when compared to all other groups. Similar effects were observed with CRP levels; CRP levels were significantly higher in the CDIH group compared with intermittent air (10.39±0.38 vs. 8.70±0.21 μg/ml, p<0.05) but the HFIH had the greatest levels of CRP (11.87±0.31 μg/ml, p<0.05). In the HFIA group, CRP levels were not elevated (9.96±0.37 μg/ml, p=NS). Nevertheless, total antioxidant capacity and eNOS gene expression were not significantly different in the groups.

A: Does chronic intermittent hypoxia cause endothelial dysfunction in a mouse model of diet-induced obesity?
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Q: We recently demonstrated that MRI inflammation is prevalent in clinically non-swollen joints of early arthritis patients. In this study, we assessed the relevance of this subclinical inflammation with regard to radiographic progression.', '1130 joints (unilateral metacarpophalangeal 2-5, wrist and metatarsophalangeal 1-5) of 113 early arthritis patients underwent clinical examination and 1.5\u2005T MRI at baseline, and radiographs at baseline and 1 year. Two readers scored the MRIs for synovitis, bone marrow oedema (BME) and tenosynovitis according to Rheumatoid Arthritis (RA) Magnetic Resonance Imaging (MRI) Scoring System (RAMRIS). Radiographic progression over 1 year was determined using the Sharp-van der Heijde scoring method.', 'On patient level, BME, synovitis and tenosynovitis were associated with radiographic progression, independent of known risk factors (p=0.003, 0.001 and 0.011, respectively). Of all non-swollen joints (n=932), 232 joints (26%) had subclinical inflammation (≥1 MRI-inflammation feature present). These joints were distributed among 91% of patients. Radiographic progression was present in 4% of non-swollen joints with subclinical inflammation compared to 1% of non-swollen joints without subclinical inflammation (relative risks (RR) 3.5, 95% CI 1.3 to 9.6). Similar observations were done for BME (RR5.3, 95% CI 2.0 to 14.0), synovitis (RR3.4, 95% CI 1.2 to 9.3) and tenosynovitis (RR3.0, 95% CI 0.7 to 12.7) separately.

A:
Is mRI-detected subclinical joint inflammation associated with radiographic progression?
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