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:
Accurate evaluation of the biological behavior of Gastrointestinal stromal tumor and careful selection of patients with a high risk for tumor recurrence are necessary. In the present study, we analyzed prognostic factors in patients with GIST.', 'A total of 214 patients who had undergone curative resection of a localized primary gastric GIST without adjuvant therapy were enrolled in this retrospective study. Prognostic factors were analyzed. The growth pattern was classified as intramural, endoluminal, exoluminal, or mixed- type.', 'On univariate and multivariate analyses, recurrence was predicted by exoluminal or mixed-type (hazard ratio [HR]=3.7, p=0.043), tumor size of >3.5 cm (HR=7.1, p=0.01), and mitotic rate of >5/50 high-power fields (HR=7.9, p<0.001).
answer:
Is macroscopic type a prognostic factor for recurrence-free survival after resection of gastric GIST?


question:
Our objective was to study the direct effects of meconium on isolated umbilical artery and vein in vitro.', "Intact umbilical artery and vein rings were suspended in 5 ml organ baths containing kreb's solution (pH 7.2, 37 degrees C; bubbled with 2.5% oxygen and 8.07% carbon dioxide, balance nitrogen) for isometric tension recording. Meconium alone (final bath concentration 1%), centrifuged and filtered meconium, and meconium with the lipid fraction removed (separated into < 30,000 kd and > 30,000 kd) were added to the baths. Some vessels were also incubated in 1% meconium for 30 minutes, after which the meconium was washed out. Concentration-response curves to U46619 were obtained. The negative log of the concentration that evokes 50% of the maximal contraction was determined.", 'Umbilical artery and vein had no sustained response to meconium. Tension that developed by rings exposed to meconium was significantly less than control at all concentrations of U46619. There was some loss of the efficacy of meconium after centrifugation-filtration and washing out. Meconium without the lipid fraction had less inhibitory effect than did native meconium.
answer:
Does meconium inhibit the contraction of umbilical vessels induced by the thromboxane A2 analog U46619?


question:
Intestinal cells are constantly exposed to luminal toxins. In this study, we investigated the effect of cellular stress caused by valinomycin, which is structurally and functionally similar to the bacterial toxin cereulide, on quercetin metabolism and cellular localization in undifferentiated cells.', 'Coadministration of quercetin and valinomycin (50 μM quercetin/0.05 μM valinomycin) reduced intracellular reactive oxygen species content and increased cell viability (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) of Caco-2 cells compared to valinomycin-only (0.05 μM) treatment. Quercertin was effectively metabolized into methyl, glucuronide, and sulfate conjugates, which were mostly secreted into to the culture medium. Three different O-methylated quercetin isomers were detected. Two were exported from the cells and one remained intracellularly. Further, valinomycin caused an increase in the intracellular accumulation of O-methylated quercetin metabolites compared to cells treated only with quercetin. In valinomycin-untreated cells, quercetin and O-methylated quercetin metabolite were localized in the cell membrane, whereas valinomycin treatment resulted in their uptake by the cells.
answer:

Does quercetin mitigate valinomycin-induced cellular stress via stress-induced metabolism and cell uptake?