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: Doxorubicin is a cytotoxic drug with potential for severe myelosuppression that is highly variable and poorly predictable.', 'We correlated CBR1 and CBR3 genotypes with the pharmacokinetics and pharmacodynamics of doxorubicin in 101 Southeast Asian breast cancer patients receiving first-line doxorubicin.', 'A common CBR3 11G>A variant was associated with lower doxorubicinol area under the concentration-time curve (AUC)/doxorubicin AUC metabolite ratio (P=0.009, GG vs. AA; trend test, P=0.004), lower CBR3 expression in breast tumor tissue (P=0.001, GG vs. AA), greater tumor reduction (P=0.015, GG vs. AA), and greater percentage reduction of leukocyte and platelet counts at nadir (trend test, P < or = 0.03). Chinese and Malays had higher frequency of the CBR3 11G>A variant than Indians (P < or = 0.002). Another variant CBR3 730G>A was associated with higher doxorubicinol AUC (P=0.009, GG vs. AA) and CBR3 expression in breast tumor tissue (P=0.001, GG vs AA).

Answer: Does genotype of human carbonyl reductase CBR3 correlate with doxorubicin disposition and toxicity?


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: Pulmonary vein (PV) isolation is a curative treatment for patients with atrial fibrillation. The aim of this study was to evaluate prospectively the effects of adenosine administration on the PV activity and atrio-venous conduction after PV isolation.', 'Twenty-nine patients (21 m; age: 55+/-8 years) were submitted to ostial PV isolation guided by basket catheter recordings. After successful isolation, the effects of a 12 mg intravenous bolus of adenosine were tested in 62 PVs. In 22/62 PVs (35%), left atrium (LA)-to-PV conduction was transiently (16.6+/-7.1 s, range: 3.8-27.9 s) or permanently (3 PVs) restored in response to adenosine administration. The prevalence of this phenomenon was 39% in left superior PVs, 43% in right superior PVs, and 22% in left inferior PVs (p=0.365). It occurred more frequently in the presence of dissociated PV activity (11/15 PVs, 73% vs. 11/47 PVs, 23%; p=0.002), whereas it was not influenced by the median duration of the radiofrequency current (RFC) delivery for each PV [19 (IQR: 12-26) min vs. 16 (IQR: 11-24) min: p=0.636]. A lengthening or shortening of the LA-PV conduction time was observed at LA-PV conduction appearance and disappearance in 36% and 55% of the cases, respectively. Further RFC applications (median: 5.5 min, IQR: 4-11 min) at the residual conduction breakthrough(s) indicated by the basket catheter recordings definitively eliminated adenosine-induced recovery of LA-PV conduction in all cases. Finally, when present, intrinsic PV discharge was invariably depressed by adenosine administration.

Answer:
Does adenosine restore atrio-venous conduction after apparently successful ostial isolation of the pulmonary veins?