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: Tubuloglomerular feedback (TGF) is an important mechanism in control of signal nephron glomerular filtration rate. The oxidative stress in the macula densa, primarily determined by the interactions between nitric oxide (NO) and superoxide (O2-), is essential in maintaining the TGF responsiveness. However, few studies examining the interactions between and amount of NO and O2- generated by the macula densa during normal and hypertensive states.', 'In this study, we used isolated perfused juxtaglomerular apparatus to directly measure the amount and also studied the interactions between NO and O2- in macula densa in both physiological and slow pressor Angiotensin II (Ang II)-induced hypertensive mice.', 'We found that slow pressor Ang II at a dose of 600\xa0ng kg(-1) min(-1) for two weeks increased mean arterial pressure by 26.1\xa0± 5.7\xa0mmHg. TGF response increased from 3.4\xa0±\xa00.2\xa0μm in control to 5.2\xa0±\xa00.2\xa0μm in hypertensive mice. We first measured O2- generation by the macula densa and found it was undetectable in control mice. However, O2- generation by the macula densa increased to 21.4\xa0±\xa02.5 unit min(-1) in Ang II-induced hypertensive mice. We then measured NO generation and found that NO generation by the macula densa was 138.5\xa0±\xa09.3 unit min(-1) in control mice. The NO was undetectable in the macula densa in hypertensive mice infused with Ang II.

Answer: Does oxidative status in the macula densa modulate tubuloglomerular feedback responsiveness in angiotensin II-induced hypertension?


Question: Endoscopic snare papillectomy (ESP) is a viable alternative to surgical treatment of ampullary adenomas and T1N0 stage ampullary carcinomas. The main drawback of this technique is the high risk of acute pancreatitis post procedure.The aim of this study was to assess the efficacy, safety, and long-term results of this procedure, and to determine whether routine pancreatic intubation facilitated by intraductal methylene blue (MB) injection reduces the risk for pancreatitis.', 'Between 2004 and 2011, 56 consecutive patients underwent ESP. Before resection, the pancreatic duct was cannulated, and MB was injected intraductally to facilitate stent placement after ampullectomy.', 'ESP was performed en bloc in 45 patients with histological findings of low-grade dysplasia (39%), high-grade dysplasia (25%), carcinoma (32.5%), and others (3.5%). The morbidity rate was 19.5%: acute pancreatitis (n=6), bleeding (n=4), perforation (n=1), and sepsis (n=1). Pancreatic intubation was performed in 89% of the patients. Postprocedure pancreatitis occurred significantly less in the patients with a pancreatic stent than in those without: 3/49 versus 3/6, P=0.013. ESP was considered as curative in 39 patients (75%). Of the 12 recurrences (25%), 10 were managed endoscopically, but with higher morbidity (acute pancreatitis=40%).

Answer: Does pancreatic intubation facilitated by methylene blue injection decrease the risk for postpapillectomy acute pancreatitis?


Question: Retrospective cohort study.', 'To compare short-term morbidity for primary and revision posterior lumbar fusions.', 'Revision lumbar fusions are unfortunately relatively common. Previous studies have described an increased risk of postoperative complications after revision lumbar fusion; however, these studies have been limited by small sample sizes, poor data quality, and/or narrow outcome measures. There is a need to validate these findings using a high-quality, national cohort of patients to have an accurate assessment of the relative risk of revision posterior lumbar fusions compared with primary lumbar fusion.', 'The prospectively-collected American College of Surgeons National Surgical Quality Improvement Program database was used to identify patients that underwent undergoing primary and revision posterior lumbar fusion from 2005 to 2013. The occurrence of individual and aggregated postoperative complications within 30 days, along with rates of blood transfusion and readmission, were compared between primary and revision procedures using bivariate and multivariate Poisson regression with robust error variance to control for patient and operative characteristics. Operative time and postoperative length of stay were compared between groups using bivariate and multivariate linear regression.', 'Of the 14,873 posterior lumbar fusion procedures that met inclusion criteria, 1287 (8.7%) were revision cases. There were no differences in the rates of 30-day postoperative complications or readmission between primary and revision posterior lumbar fusion using multivariate analysis to control for patient and operative characteristics. Similarly, no significant differences were found for operative time or postoperative length of stay. There was an increased rate of blood transfusion for revision surgery compared with primary surgery (relative risk 1.4, P\u200a<\u200a0.001).

Answer:
Do primary and Revision Posterior Lumbar Fusion Have Similar Short-Term Complication Rates?