TASK DEFINITION: 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.
PROBLEM: Context: Natriuretic peptide (NP) levels are routinely employed as useful diagnostic and prognostic tools in the evaluation of patients with heart failure (HF). As hospitalization is the major consumer of healthcare resources, the prognostic power of admission NPs with regard to the duration of hospitalization deserves further investigation.', 'We assessed retrospectively the association between NP values sampled shortly following unplanned admission and the duration of hospitalization in 2978 patients admitted to a cardiology department. Duration of hospitalization (hours) and survival were determined by interrogation of the electronic medical records system. Associations with peptide levels were estimated using regression models and receiver operating characteristic (ROC) analysis. The results demonstrate a significant positive relationship between NP levels and the duration of hospitalization, after adjusting for age (P < 0.001). The median duration of hospitalization for the lowest BNP and NT-proBNP quintiles were 80 and 97 h, respectively, vs. 224.5 and 236 h for the highest quintiles. Using cut-off levels of 115 pmol/L for BNP and 390 pmol/L for NT-proBNP, the peptides have a positive predictive value of 78% and 85% for a stay >4 days. During follow-up, NP levels were strongly predictive of all-cause mortality.
Answer: The results quantify the strong relationship between NP levels taken following an unplanned admission to a cardiology department and the duration of hospitalization. This information permits improved identification of a patient population likely to require a prolonged hospital stay and consume more healthcare resources. Such patients may require a more aggressive diagnostic, treatment, and management strategy.

SOLUTION: Do natriuretic peptide levels taken following unplanned admission to a cardiology department predict the duration of hospitalization?

PROBLEM: Context: A functional vacuolar adenosine triphosphatase (v-ATPase) complex regulates canonical Wnt/β-catenin signaling. The goal of this study was to identify the distribution of the v-ATPase in human and murine models of pancreatic intraepithelial neoplasms (PanINs) and assess its role in Wnt/β-catenin signaling.', 'We evaluated the immunolabeling pattern of the v-ATPase in human PanIN specimens and murine PanIN-1 and PanIN-2 lesions obtained from Ptf1a(Cre/+); LSL-Kras(G12D) mice. Wnt/β-catenin signaling was interrogated in primary PanIN cells by examining the phosphorylated levels of its surface coreceptor, low-density lipoprotein receptor-related protein-6 (LRP6), and its intracellular effector, nonphosphorylated β-catenin. The response of primary PanIN cells to epidermal growth factor (EGF) was assessed in the absence and presence of the v-ATPase inhibitor, concanamycin.', 'In advanced (PanIN-2), but not early (PanIN-1), lesions, the v-ATPase assumed a polarized phenotype. Blocking the v-ATPase disrupted Wnt/β-catenin signaling in primary PanIN cells despite significantly higher levels of the total and activated Wnt cell surface coreceptor, LRP6. Vacuolar adenosine triphosphatase blockade significantly decreased the total and activated levels of EGF receptor, a determinant of PanIN progression. The activation of EGF receptor and its intracellular mediator, p44/42 mitogen-activated protein kinase, was also reduced by v-ATPase blockade. This led to diminished proliferation in response to EGF ligand.
Answer: The v-ATPase regulates Wnt/β-catenin and EGF receptor signaling in PanINs.

SOLUTION: Does polarization of the vacuolar adenosine triphosphatase delineate a transition to high-grade pancreatic intraepithelial neoplasm lesions?

PROBLEM: Context: Lactate dehydrogenase-elevating virus (LDV) is a natural infectious agent of mice. Like several other viruses, LDV causes widespread and very rapid but transient activation of both B cells and T cells in lymphoid tissues and the blood. The mechanism of this activation has not been fully described and is the focus of the current studies.', "A known inducer of early lymphocyte activation is IFNalpha, a cytokine strongly induced by LDV infection. Neutralization of IFNalpha in the plasma from infected mice ablated its ability to activate lymphocytes in vitro. Since the primary source of virus-induced IFNalpha in vivo is often plasmacytoid dendritic cells (pDC's), we depleted these cells prior to LDV infection and tested for lymphocyte activation. Depletion of pDC's in vivo eradicated both the LDV-induced IFNalpha response and lymphocyte activation. A primary receptor in pDC's for single stranded RNA viruses such as LDV is the toll-like receptor 7 (TLR7) pattern recognition receptor. Infection of TLR7-knockout mice revealed that both the IFNalpha response and lymphocyte activation were dependent on TLR7 signaling in vivo. Interestingly, virus levels in both TLR7 knockout mice and pDC-depleted mice were indistinguishable from controls indicating that LDV is largely resistant to the systemic IFNalpha response.
Answer: Results indicate that LDV-induced activation of lymphocytes is due to recognition of LDV nucleic acid by TLR7 pattern recognition receptors in pDC's that respond with a lymphocyte-inducing IFNalpha response.

SOLUTION:
Does lactate dehydrogenase-elevating virus induce systemic lymphocyte activation via TLR7-dependent IFNalpha responses by plasmacytoid dendritic cells?