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.
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Question: It has already been demonstrated that the rat esophagus produces retinoic acid from retinol. In this study, this process is further characterized and the effect of acetaldehyde examined to elucidate the possible mechanisms behind the epidemiological evidence that the incidence of esophageal cancer is higher in alcoholics.', 'Rat esophageal samples were incubated with all-trans retinal and newly formed all-trans retinoic acid (ATRA) was quantified using high-performance liquid chromatography (HPLC). Furthermore, beta-nicotinamide adenine dinucleotide (NAD)-dependent acetaldehyde oxidation by the rat esophagus was examined by tracing NAD reduction using a spectrophotometer.', 'Rat esophageal samples produced ATRA from all-trans retinal in a NAD-dependent manner and the potential was significantly attenuated by phenetyl isothiocynate, an ALDH inhibitor, or acetaldehyde depending on the concentration used. Rat esophageal samples also oxidized acetaldehyde of various concentrations NAD dependently. The ATRA formation potential that was temporarily inhibited by acetaldehyde was recovered to the control level by dialysis when the specimen was incubated with up to 50 microM of acetaldehyde.

Answer: Does acetaldehyde inhibit the formation of retinoic acid from retinal in the rat esophagus?


Question: Previous studies have shown that Fructus Ligustri Lucide (FLL) can be used to anti-cancer. However, the mechanism by which FLL mediate this effect is unclear. In the present study, aqueous extracts of FLL induced cell apoptosis in human gastric carcinoma cell was investigated.', 'The cell viability was detected by the CCK8 assay. The cell apoptosis was assessed by annexin V-PI double-labeling staining and hoechst 33342 staining. The protein expression of cell cycle regulators and tumor suppressors were analyzed by western blotting.', 'Treatment of human gastric carcinoma cells with FLL induced cell death in a dose- and time-dependent manner by using CCK8 assay. Consistent with the CCK8 assay, the flow cytometry results showed that the proportion of the early and terminal phase of apoptosis cells had gained after FLL treatment as compared to untreated group. Moreover, human gastric carcinoma cells were exposed to the aqueous extracts of FLL for 48 h, which resulted in an accumulation of cells in G2/M phase. Apoptotic bodies were clearly observed in human gastric carcinoma that had been treated with FLL for 48 h and then stained with Hochest 33342. Treatment of gastric carcinoma cells with increasing doses of FLL and increasing durations significantly increased the protein expression of Bax and Caspase3, decreased the anti-apoptotic Bcl-2 level. The expression of CDC2 and cdc25C were downregulated upon FLL treatment in human gastric carcinoma. In contrast, p53 and p21 were obviously upregulated by FLL treatment in a concentration-dependent manner.

Answer: Do aqueous extracts of Fructus Ligustri Lucide induce gastric carcinoma cell apoptosis and G2/M cycle arrest?


Question: To investigate the potential efficacy of real-time contrast-enhanced power Doppler sonography in the differentiation of benign and malignant adnexal masses in a pilot study.', 'Before surgical treatment, adnexal masses were prospectively evaluated with power Doppler sonography before and after injection of a contrast agent. Real-time postinjection sequences were computerized with time-intensity analysis software to determine an enhancement curve and contrast parameters. The intraobserver and interobserver reproducibilities of these criteria were assessed on a subsample. These contrast parameters were compared between benign and malignant tumors using logistic regression. Sensitivity and specificity were used to compare contrast parameters with sonographic and Doppler variables.', 'Ninety-nine women were included, for a total of 101 adnexal masses. There were 23 cases of ovarian malignancies and 78 benign adnexal lesions. Our procedure had excellent intraobserver and interobserver reproducibility, with an average intraclass correlation coefficient of 0.92. The time before enhancement and intensity ratio did not reliably differentiate between the benign and malignant masses. Washout times and areas under the curves were significantly greater in ovarian malignancies than in other benign tumors (P < .001), leading to sensitivity estimates between 96% and 100% and specificity estimates between 83 and 98%. Contrast parameters had slightly higher sensitivity and slightly lower specificity when compared with transvaginal sonographic variables of the resistive index and serum cancer antigen 125 levels.

Answer:
Does contrast-enhanced sonography help in discrimination of benign from malignant adnexal masses?