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: Reactive oxygen species have been implicated as signaling molecules modulating the activity of redox-sensitive transcription factors such as nuclear factor kappa B (NF-kappaB). Recently, the transcription factor hypoxia-inducible factor-1 (HIF-1), known to mediate gene expression by hypoxia, has been found to be also activated by nonhypoxic factors in a redox-sensitive manner. We therefore aimed to elucidate the link between these 2 important redox-sensitive transcription factors.', 'In pulmonary artery smooth muscle cells, reactive oxygen species generated either by exogenous H2O2 or by a NOX4-containing NADPH oxidase stimulated by thrombin activated or induced NF-kappaB and HIF-1alpha. The reactive oxygen species-mediated HIF-1alpha induction occurred on the transcriptional level and was dependent on NF-kappaB. Transfection experiments with wild-type or mutant HIF-1alpha promoter constructs revealed the presence of a yet unidentified NF-kappaB binding element. Gel shift analyses and chromatin immunoprecipitation verified binding of NF-kappaB to this site. Furthermore, reactive oxygen species enhanced expression of plasminogen activator inhibitor-1, which was prevented by dominant-negative IkappaB or mutation of the HIF-1 binding site within the plasminogen activator inhibitor-1 promoter.
Answer: These findings show for the first time to our knowledge that reactive oxygen species directly link HIF-1alpha and NF-kappaB, implicating an important pathophysiological role of this novel pathway in disorders associated with elevated levels of reactive oxygen species.
Do reactive oxygen species activate the HIF-1alpha promoter via a functional NFkappaB site?

Context: Vessel formation is a crucial event in tissue repair after injury. Thus, one assumption of innovative therapeutic approaches is the understanding of its molecular mechanisms. Notwithstanding our knowledge of the role of Protein Kinase C epsilon (PKCε) in cardio-protection and vascular restenosis, its role in vessel progenitor differentiation remains elusive.', 'Given the availability of PKCε pharmacological modulators already tested in clinical trials, the specific aim of this study is to unravel the role of PKCε in vessel progenitor differentiation, with implications in vascular pathology and vasculogenesis.', 'Mouse Peri-Vascular Adipose Tissue (PVAT) was used as source of mesenchymal vessel progenitors. VEGF-induced differentiation of PVAT cells down-regulates both PKCε and p-PAK1 protein expression levels. PKCε overexpression and activation: i) reduced the expression levels of SMA and PECAM in endothelial differentiation of PVAT cells; ii) completely abrogated tubules formation in collagen gel assays; iii) increased the expression of p-PAK1.
Answer: PKCε negatively interferes with vessel progenitor differentiation via interaction with PAK-1.
Is pKCε a negative regulator of PVAT-derived vessel formation?

Context: Multi-atlas fusion is a promising approach for computer-assisted segmentation of anatomic structures. The purpose of this study was to evaluate the accuracy and time efficiency of multi-atlas segmentation for estimating spleen volumes on clinically acquired computed tomography (CT) scans.', 'Under an institutional review board approval, we obtained 294 de-identified (Health Insurance Portability and Accountability Act-compliant) abdominal CT scans on 78 subjects from a recent clinical trial. We compared five pipelines for obtaining splenic volumes: Pipeline 1 - manual segmentation of all scans, Pipeline 2 - automated segmentation of all scans, Pipeline 3 - automated segmentation of all scans with manual segmentation for outliers on a rudimentary visual quality check, and Pipelines 4 and 5 - volumes derived from a unidimensional measurement of craniocaudal spleen length and three-dimensional splenic index measurements, respectively. Using Pipeline 1 results as ground truth, the accuracies of Pipelines 2-5 (Dice similarity coefficient, Pearson correlation, R-squared, and percent and absolute deviation of volume from ground truth) were compared for point estimates of splenic volume and for change in splenic volume over time. Time cost was also compared for Pipelines 1-5.', 'Pipeline 3 was dominant in terms of both accuracy and time cost. With a Pearson correlation coefficient of 0.99, average absolute volume deviation of 23.7\u2009cm(3), and time cost of 1 minute per scan, Pipeline 3 yielded the best results. The second-best approach was Pipeline 5, with a Pearson correlation coefficient of 0.98, absolute deviation of 46.92\u2009cm(3), and time cost of 1 minute 30 seconds per scan. Manual segmentation (Pipeline 1) required 11 minutes per scan.
Answer: A computer-automated segmentation approach with manual correction of outliers generated accurate splenic volumes with reasonable time efficiency.

Does improving Spleen Volume Estimation Via Computer-assisted Segmentation on Clinically Acquired CT scan?