Given a passage with a context and an answer, 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.

Context: 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-γ 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 κB ligand (RANKL)/osteoprotegerin (OPG) ratio significantly co-varied (ρ = 0.52, P < 0.01), independent of the level of local inflammation.
Answer: Synovial CXCL13 appears to be a marker of a more severe pattern of RA disease, characterized by increased lymphocyte activation and bone remodelling beyond the level of conventional markers of inflammation.
Are high expression levels of the B cell chemoattractant CXCL13 in rheumatoid synovium a marker of severe disease?

Context: Oligonol, mainly found in lychee fruit, is an antioxidant polyphenolic compound which has been shown to have anti-inflammatory and anti-cancer properties. The detailed mechanisms by which oligonol may act as an anti-aging molecule have not been determined.', 'In this study, we evaluated the ability of oligonol to modulate sirtuin (SIRT) expression in human lung epithelial (A549) cells. Oligonol was added to A549 cells and reactive oxygen species production, mitochondrial superoxide formation, and p21 protein levels were measured. Signaling pathways activated upon oligonol treatment were also determined by western blotting. Furthermore, the anti-aging effect of oligonol was evaluated ex vivo in mouse splenocytes and in vivo in Caenorhabditis elegans.', 'Oligonol specifically induced the expression of SIRT1, whose activity is linked to gene expression, metabolic control, and healthy aging. In response to influenza virus infection of A549 cells, oligonol treatment significantly up-regulated SIRT1 expression and down-regulated viral hemagglutinin expression. Oligonol treatment also resulted in the activation of autophagy pathways and the phosphorylation of AMP-activated protein kinase (AMPK). Furthermore, oligonol-treated spleen lymphocytes from old mice showed increased cell proliferation, and mRNA levels of SIRT1 in the lungs of old mice were significantly lower than those in the lungs of young mice. Additionally, in vivo lethality assay revealed that oligonol extended the lifespan of C. elegans infected with lethal Vibrio cholerae.
Answer: These data demonstrated that oligonol may act as an anti-aging molecule by modulating SIRT1/autophagy/AMPK pathways.
Does oligonol promote anti-aging pathways via modulation of SIRT1-AMPK-Autophagy Pathway?

Context: We characterized cardiac surgery-induced dynamic changes of the corrected QT (QTc) interval and tested the hypothesis that genetic factors are associated with perioperative QTc prolongation independent of clinical and procedural factors.', 'All study subjects were ascertained from a prospective study of patients who underwent elective cardiac surgery during August 1999 to April 2002. We defined a prolonged QTc interval as > 440 msec, measured from 24-hr pre- and postoperative 12-lead electrocardiograms. The association of 37 single nucleotide polymorphisms (SNPs) in 21 candidate genes -involved in modulating arrhythmia susceptibility pathways with postoperative QTc changes- was investigated in a two-stage design with a stage I cohort (n = 497) nested within a stage II cohort (n = 957). Empirical P values (Pemp) were obtained by permutation tests with 10,000 repeats.', 'After adjusting for clinical and procedural risk factors, we selected four SNPs (P value range, 0.03-0.1) in stage I, which we then tested in the stage II cohort. Two functional SNPs in the pro-inflammatory cytokine interleukin-1β (IL1β), rs1143633 (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.53 to 0.95; Pemp = 0.02) and rs16944 (OR, 1.31; 95% CI, 1.01 to 1.70; Pemp = 0.04), remained independent predictors of postoperative QTc prolongation. The ability of a clinico-genetic model incorporating the two IL1B polymorphisms to classify patients at risk for developing prolonged postoperative QTc was superior to a clinical model alone, with a net reclassification improvement of 0.308 (P = 0.0003) and an integrated discrimination improvement of 0.02 (P = 0.000024).
Answer: The results suggest a contribution of IL1β in modulating susceptibility to postoperative QTc prolongation after cardiac surgery.

Are interleukin-1β gene variants associated with QTc interval prolongation following cardiac surgery : a prospective observational study?