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.
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Question: Context: Evidence obtained from porcine cell cultures and experiments in laboratory animals indicates that transmembrane transporters may play a role in the distribution of the active morphine metabolite morphine-6-glucuronide (M6G). This was evaluated in a study in healthy volunteers.', 'Ten subjects received an intravenous M6G infusion for 30 min at a dosage of 0.5 mg/kg body weight, leading to M6G plasma concentrations approximately two to three times higher than those observed with analgesic morphine doses in subjects with normal kidney function. In a randomized, double-blind, three-way crossover fashion, subjects received 800 mg quinidine for inhibition of P-glycoprotein; 500 mg probenecid for inhibition of other transporters, including organic anion transporter peptide, multidrug resistance-related protein, and organic anion transporter families; or placebo 1 h before the start of M6G administration. Plasma concentrations of M6G and pupil size were measured for 7 h.', 'Probenecid pretreatment resulted in a decrease in the clearance of M6G from 8.3 +/- 1 l/h to 6.7 +/- 1.3 l/h (factor of 0.8; P < 0.05 vs. placebo cotreatment). This was paralleled by an increase by a factor of 1.2 of the area under the miotic effect-versus-time curves (P < 0.05 vs. placebo). In contrast, quinidine pretreatment had no influence on the pharmacokinetics of M6G.
Answer: The active morphine metabolite is subject to transmembrane transport by transporters inhibited by probenecid in humans.

Answer: Does probenecid interact with the pharmacokinetics of morphine-6-glucuronide in humans?


Question: Context: Mast cells have been associated with obliterative bronchiolitis (OB) in human pulmonary allografts, although their role in the development of OB remains unknown.', 'In this study, we evaluated the role of mast cells in pulmonary allograft rejection using an orthotopic rat pulmonary allograft model that utilizes chronic aspiration of gastric fluid to reliably obtain OB. Pulmonary allograft recipients (n = 35) received chronic aspiration of gastric fluid with (n = 10) and without (n = 16) treatment with a mast cell membrane stabilizer, cromolyn sodium, or chronic aspiration with normal saline (n = 9) as a control.', 'The acute graft injury associated with long ischemic time in the model (6 hours total ischemic time; typical acute graft injury rate ~30%) was apparently blocked by cromolyn, because peri-operative mortality associated with the acute graft injury was not observed in any of the animals receiving cromolyn (p = 0.045). Further, the rats receiving cromolyn developed significantly fewer OB lesions than those treated with gastric fluid alone (p < 0.001), with a mean reduction of 46% of the airways affected.
Answer: These findings provide impetus for further studies aimed at elucidating the effects of cromolyn and the role of mast cells in pulmonary allotransplantation.

Answer: Does cromolyn ameliorate acute and chronic injury in a rat lung transplant model?


Question: Context: There is no consensus about the ideal method for diagnosis in patients who have already undergone endoscopic ultrasound fine needle aspiration (EUS-FNA), and the inconclusive material is often obtained. The aim was to evaluate the diagnostic yield of the second EUS-FNA of pancreatic lesions.', 'A retrospective analysis of prospectively collected data of patients with EUS-FNA of pancreatic lesions is performed. All patients who underwent more than one EUS-FNA for the evaluation of suspected pancreatic cancer over a 7-year period were included in the analysis.', 'A total of 296 EUS-FNAs of the pancreas were performed in 257 patients. The diagnostic yield with the first EUS-FNA was 78.6% (202/257). Thirty-nine (13.3%) FNAs were repeated in 34 patients; 17 (50%) patients were women. The mean ± standard deviation (SD) age was 58.8 ± 16.1 years. The location of the lesions in the pancreatic gland, from which the second biopsies were taken, was head of the pancreas, n = 28 (82.4%), body of the pancreas, n = 3 (8.8%), and tail, n = 3 (8.8%). The mean ± SD of the size of the lesion was 36.3 ± 14.6 mm. The second EUS-FNA was more likely to be positive for diagnosis in patients with an "atypical" histological result in the first EUS-FNA (odds ratio [OR]: 4.04; 95% confidence interval [CI]: 0.9-18.3), in contrast to patients with a first EUS-FNA reported as "normal" (OR: 0.21; 95% CI: 0.06-0.71). Overall, the diagnostic yield of the second EUS-FNA was 58.8% (20/34) with an increase to 86.3% overall (222/257).
Answer: Repeat EUS-FNA in pancreatic lesions is necessary in patients with a negative first EUS-FNA because it improves the diagnostic yield.

Answer:
Is repeat endoscopic ultrasound fine needle aspiration after a first negative procedure useful in pancreatic lesions?