TASK DEFINITION: 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.
PROBLEM: The proteasome is a major cellular proteinase. Its activity is modulated by cellular oxidants. Hepatitis C core protein and ethanol exposure both cause enhanced oxidant generation. The aim was to investigate whether core protein, by its ability to generate oxidants, alters proteasome activity and whether these alterations are further affected by ethanol exposure.', 'These interactions were examined in Huh-7 cell lines that expressed inducible HCV core protein and/or constitutive cytochrome P450 2E1 (CYP2E1) and as purified components in a cell-free system. Chymotrypsin-like proteasome activity was measured fluorometrically.', 'Proteasome activity in core-positive 191-20 cells was 20% higher than that in core-negative cells and was enhanced 3-fold in CYP2E1-expressing L14 cells. Exposure of core-positive cells to glutathione ethyl ester, catalase, or the CYP2E1 inhibitor diallyl sulfide partially reversed the elevation of proteasome activity in core-positive cells, whereas ethanol exposure suppressed proteasome activity. The results indicate that proteasome activity was up-regulated by low levels of core-induced oxidative stress but down-regulated by high levels of ethanol-elicited stress. These findings were partially mimicked in a cell-free system. Addition of core protein enhanced the peptidase activity of purified 20S proteasome containing the proteasome activator PA28 and was further potentiated by addition of liver mitochondrial and/or microsome fractions. However, proteasome activation was significantly attenuated when fractions were obtained from ethanol-fed animals.

SOLUTION: Is proteasome activation by hepatitis C core protein reversed by ethanol-induced oxidative stress?

PROBLEM: To investigate the effects of copper on permeability and P-glycoprotein (P-gp) of Caco-2 cell monolayers.', 'The differentiated Caco-2 cell model was used in this study. Permeability of cell monolayers was reflected by monitoring transepithelial electrical resistance (TEER); distribution of tight junctional protein ZO-1 was measured by immunofluorescent staining; F actin was measured by fluorescence staining; and Activity of P-gp was reflected by changes of transcellular transport and accumulation of Rho-123 in Caco-2 cells.', "Apical treatment with copper (30 - 100 micromol/L, Hanks' buffered salt solution, up to 3 hours) induced a time- and concentration-dependent increase in permeability reflected by progressive decrease of TEER of Caco-2 cell monolayers, accompanied by deorganization of F actin, but without significant effects on tight junctional protein ZO-1; at a dose without any adverse effects on viability and permeability of Caco-2 monolayers, copper treatment (300 micromol/L, complete medium, 24 hours) decreased Papp(BL-->AP) from 7.37 +/- 0.20 x 10(-6) cm/s (controls) to (6.43 +/- 0.27) x 10(-6) cm/s, the increased Papp(AP-->BL) from (1.23 +/- 0.05) x 10(-7) cm/s (controls) to (3.41 +/- 0.08) x 10(-7) cm/s, and enhanced the intracellular Rho-123 from (0.31 +/- 0.01) nmol/filter (controls) to (0.50 +/- 0.03) nmol/filter.

SOLUTION: Does [ Copper treatment alter the barrier functions of human intestinal Caco-2 cells ]?

PROBLEM: Video capsule endoscopy (VCE) is limited by incomplete procedures. There are also contraindications to the standard ingestion of the capsule that require endoscopic placement. Our aim was to compare the study completion rate of VCE after oral ingestion and endoscopic deployment.', 'We performed a review of all VCE from April 2010 through March 2013. Inpatient and outpatient cohorts grouped by the method of capsule delivery were formed and compared. Multivariable logistic regression modeling was utilized adjusting for variables with a P\xa0value ≤\u200a0.1 in group comparisons. Log-rank analysis was used to compare transit times.', 'A total of 687 VCE were performed, including 316 inpatient (36 endoscopic deployment, 280 oral ingestion) and 371 outpatient (20 endoscopic deployment, 351 oral ingestion). For VCE on hospitalized patients, the completion rates were similar after endoscopic deployment and oral ingestion (72\u200a% vs 73\u200a%, P\u200a=\u200a0.94). The completion rates were also similar for ambulatory patients (90\u200a% vs 87\u200a%, P\u200a=\u200a0.69). There remained no difference after multivariable modeling for inpatients (P\u200a=\u200a0.71) and outpatients (P\u200a=\u200a0.46). Total transit times were not significantly different.

SOLUTION:
Are video capsule endoscopy completion and total transit times similar with oral or endoscopic delivery?