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: Although the presence of perineural invasion has been recognized as a poor prognostic factor in extrahepatic cholangiocarcinoma, the molecular mechanisms of perineural invasion in extrahepatic cholangiocarcinoma remain unclear. Nerve growth factor has been reported to be a candidate predictive biomarker of perineural invasion in some cancers.', 'To investigate the impact of intratumoral nerve growth factor expression in resected extrahepatic cholangiocarcinoma on survival.', 'Intratumoral nerve growth factor expression was investigated immunohistochemically in 112 patients with resected extrahepatic cholangiocarcinoma. Associations between nerve growth factor expression and clinicopathological factors were statistically evaluated, and risk factors for poor survival were analyzed using univariate and multivariate analyses.', 'High and low nerve growth factor expression was observed in 62 (55%) and 50 (45%) patients, respectively. For all 112 patients, no significant correlation was found between nerve growth factor expression and presence of perineural invasion (P = 0.942). Moreover, nerve growth factor expression was not associated with recurrence-free survival (P = 0.861) and overall survival (P = 0.973). In multivariate analysis, lymph node metastasis (P = 0.004) was identified as an independent risk factor for early recurrence and the presence of perineural invasion (P = 0.002) and lymph node metastasis (P < 0.001) was identified as independent risk factors for poor survival.
Answer: Intratumoral nerve growth factor expression is not associated with perineural invasion or recurrence-free and overall survival in patients with resected extrahepatic cholangiocarcinoma.

Answer: Is nerve Growth Factor Expression Associated with Perineural Invasion in Extrahepatic Cholangiocarcinoma?


Question: Context: To estimate the prevalence of asthma, allergic rhinitis, and atopic dermatitis among school children in the region of Primorsko-goranska County in Croatia, and compare the results with data from other countries.', 'The study was conducted during the 2001-2002 school year, in complete adherence to the Phase One protocol of the International Study of Asthma and Allergies in Childhood (ISAAC). The target population comprised two age groups (6-7 and 13-14 years) in the region of Primorsko-Goranska County in Croatia. Data were collected using standardized ISAAC written questionnaire and asthma video questionnaire.', 'There were 1,634 participating children in the 6-7 age group (response rate 80.3%) and 2,194 participating children in the 13-14 age group (response rate 89.8%). Estimated 12-month prevalence rates of symptoms were: wheezing 9.7% and 8.4%, allergic rhinitis symptoms 16.9% and 17.5%, allergic rhinoconjunctivitis symptoms 5.6% and 6.7%, and atopic dermatitis symptoms 5.4% and 3.4%, for younger and older age group, respectively.
Answer: Results suggest an increase in the prevalence of atopic disease symptoms in north-west part of Croatia over the last few decades when compared to prior studies. The results are suitable for international comparison, suggesting that this part of Croatia is a county with a moderate prevalence of atopic diseases in the pediatric population. The results represent a baseline for further epidemiological research of asthma and allergic diseases.

Answer: Is prevalence of asthma and allergic diseases in Croatian children increasing : survey study?


Question: Context: Proper fluoroscopic education and protocols may reduce the patient radiation dose but few prospective studies in urology have been performed. Using optically stimulated luminescent dosimeters we tested whether fluoroscopy time and/or entrance skin dose would decrease after educational and radiation reduction protocols.', 'At default manufacturer settings fluoroscopy time and entrance skin dose were prospectively measured using optically stimulated luminescent dosimeters in patients undergoing ureteroscopy, retrograde pyelogram/stent or percutaneous nephrolithotomy with access for stone disease. A\xa0validated radiation safety competency test was administered to urology faculty and residents before and after web based, hands-on fluoroscopy training. Default\xa0fluoroscopy settings were changed from continuous to intermittent pulse\xa0rate and from standard to half-dose output. Fluoroscopy time and entrance skin dose were then measured again.', 'The cohorts of 44 pre-protocol and 50 post-protocol patients with stones were similarly matched. The change in mean fluoroscopy time and entrance skin dose from pre-protocol to post-protocol was -0.6 minutes and -11.6 mGy (33%) for percutaneous nephrolithotomy (p = 0.62 and <0.001), 0.5 minutes and -0.1\xa0mGy (34%) for ureteroscopy (p = 0.42 and 0.31), and 0.1 minute and -0.1 mGy (29%) for retrograde pyelogram/stent (p = 0.85 and 0.49, respectively). Urologist post-training test scores increased 30% from pretraining scores (p\xa0=\xa00.1).
Answer: Radiation safety training protocols improved clinical knowledge but did not significantly alter fluoroscopy time. Changing equipment default settings to intermittent pulse rate (12 frames per second) and half-dose lowered the entrance skin dose by 30% across all endourology patients but most significantly during percutaneous nephrolithotomy. To limit patient radiation exposure fluoroscopy default settings should be decreased before all endourology procedures and image equipment manufacturers should consider lowering standard default renal settings.

Answer:
Does changing Default Fluoroscopy Equipment Settings decrease Entrance Skin Dose in Patients?