instruction:
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.
question:
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 782%, p<0.0001) when compared to the other groups (Emax: HFIA 950.7%, CDIH 942%, CDIA 971%). Also basal endothelial dependant dilation was attenuated in the HFIH group compared to the HFIA group (Emax: HFIH: 17910% vs. HFIA: 14911% in the presence of L-NAME). Levels of MDA were elevated in the CDIH group when compared to CDIA (0.680.04 vs. 0.410.03 M, p<0.05) but were greatest in the HFIH group (0.830.08 M, p<0.05). However, there was no significant increase in MDA levels in the HFIA group (0.450.03 M, 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 (10.390.38 vs. 8.700.21 g/ml, p<0.05) but the HFIH had the greatest levels of CRP (11.870.31 g/ml, p<0.05). In the HFIA group, CRP levels were not elevated (9.960.37 g/ml, p=NS). Nevertheless, total antioxidant capacity and eNOS gene expression were not significantly different in the groups.
answer:
Does chronic intermittent hypoxia cause endothelial dysfunction in a mouse model of diet-induced obesity?

question:
Motor dysfunction in complex regional pain syndrome (CRPS) is often considered a functional movement disorder. Earlier studies in patients with functional movement disorders found evidence of cortical inhibition during explicit but not implicit motor tasks, suggesting active inhibition from other brain areas. In this study, we explored whether active inhibition occurs in CRPS patients. We compared patients with CRPS with 2 control groups: healthy controls matched for age and sex, and patients whose hand was immobilized to treat a scaphoid fracture. We used transcranial magnetic stimulation to measure corticospinal excitability at rest and during motor imagery (explicit motor task) and motor observation (implicit motor task). Motor corticospinal excitation measured at rest and during implicit and explicit motor tasks was similar for CRPS patients and healthy controls. Patients with an immobilized hand showed an absence of motor cortical excitation of the corresponding hemisphere during motor imagery of tasks involving the immobilized hand, but not during motor observation. The normal motor cortical processing during motor imagery and motor observation found in the corresponding hemisphere of CPRS patients suggests that the nature of motor dysfunction in this condition differs from that described in literature for patients with functional paresis or under circumstances of limb immobilization.
answer:
Is motor cortical activity during motor tasks normal in patients with complex regional pain syndrome?

question:
The B cell chemoattractant chemokine ligand 13 (CXCL13) is emerging as a new biochemical marker in RA. This study was undertaken to dissect the relationship between CXCL13 expression levels in the synovium and clinico-pathological variables relevant to RA pathogenesis and outcome.', 'Synovial tissues from 71 RA patients were evaluated by immunohistochemistry. Thirty paired samples were used for comparative gene expression analysis by quantitative real-time PCR. CXCL13 levels were analysed in relation to cellular, molecular and clinical features of inflammation, lymphocyte activation and joint damage.', 'In patients with early disease (<12 months duration), CXCL13 expression correlated significantly with synovial markers of local disease activity and systemic inflammation. Such correlation was less evident in established RA. Notably, the association with lymphocyte infiltration and with expression of B/T cell-related activation and proliferation genes, such as activation-induced cytidine deaminase, IFN- and IL-2, remained highly significant independent of disease duration and local disease activity. Patients featuring the highest levels of CXCL13 were more frequently ACPA positive and IgG ACPA titres were increased in the high CXCL13 expression group. Furthermore, the frequency of erosive disease on radiographs was significantly higher in the upper tertile of CXCL13 expression (P = 0.01 with adjustment for disease duration and ACPA). Accordingly, synovial CXCL13 and the local receptor activator of nuclear factor B ligand (RANKL)/osteoprotegerin (OPG) ratio significantly co-varied ( = 0.52, P < 0.01), independent of the level of local inflammation.
answer:
Are high expression levels of the B cell chemoattractant CXCL13 in rheumatoid synovium a marker of severe disease?