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.

[EX Q]: To investigate the association between adenoidectomy and/or tonsillectomy in childhood and asthma, allergic rhinitis (AR), and eczema in adolescence.', 'Longitudinal birth cohort study of 1328 members born in the city of Nijmegen. Information on ear-nose-throat surgery was documented at 2, 4, and 8 years of age. In 1055 cohort members the incidence of asthma, AR, and eczema at 21 years of age was determined using the International Study of Asthma and Allergic disease in Childhood Core Questionnaire. To analyse the association between adenoidectomy and/or tonsillectomy in childhood and asthma, AR, and eczema at age 21 years, relative risks (RR) were calculated.', 'Six hundred and ninety-three (66%) members completed the questionnaire at age 21 years, of whom 104 (15%) had undergone adenoidectomy and/or tonsillectomy and 262 (38%) reported atopic disease. Children who underwent adenoidectomy and/or tonsillectomy before the age of 8 years were not more likely to develop asthma, AR, or eczema at the age of 21 years than children who did not; RR 0.93 (95% confidence limits (CL) 0.52-1.64), RR 0.94 (CL 0.68-1.30), and RR 1.00 (CL 0.59-1.68), respectively.
[EX A]: Is adenoidectomy and/or tonsillectomy in childhood associated with atopic disease later in life?

[EX Q]: Pulmonary hypertension (PH) is prognosti- cally important in chronic obstructive pulmonary disease (COPD). Since PH only weakly correlates with hypoxemia, other factors must play a role.', 'To investigate whether polymorphisms of the serotonin transporter (5HTT), serotonin-2a receptor (5HTR2a) and endothelial nitric oxide synthetase (eNOS) are related to PH in COPD.', 'In 59 COPD patients who underwent right heart catheterization, 6-min walking distance, NYHA functional class, pulmonary function tests, blood gases and 5HTT, 5HTR2a and eNOS (4ab and T298C) polymorphisms were determined.', 'Forty-nine COPD patients in NYHA functional class III-IV were included. Ten were excluded due to comorbid causes of PH (mainly chronic thromboembolic). PH (mPAP > or =25 mm Hg) was present in 55% and usually mild, but out of proportion (mPAP > or =40 mm Hg) in 12%. Patients with PH had significantly higher frequencies of the 5HTT-L-allele (52%) compared to individuals without PH (36%), and LL homozygote patients had more severe PH. In patients with out-of-proportion PH, the L-allelic frequency was even 75%. We found no association of 5HTR2a and eNOS polymorphism with PH in COPD.
[EX A]: Are genetic polymorphisms of the serotonin transporter , but not the 2a receptor or nitric oxide synthetase , associated with pulmonary hypertension in chronic obstructive pulmonary disease?

[EX Q]: Parathyroidectomy (PTx) is the most successful treatment for advanced secondary hyperparathyroidism (2HPT) not responsive to medical treatment. However, persistent HPT remains problematic after PTx if some glands remain. The clinical course in patients with persistent 2HPT was evaluated to clarify the risk for re-operation after PTx.', 'Between March 1981 and December 2001, initial total PTx with forearm autograft were performed in 1156 uraemic patients. Persistent HPT cases were defined as those in which the lowest post-operative intact parathyroid hormone (i-PTH) concentration was >60 pg/ml, and patients were classified into groups A, B and C, with i-PTH concentrations of >or=500, 300-500 and 60-300 pg/ml, respectively. These patients were followed for 7-234 months after PTx.', 'Persistent HPT was identified in 49/1156 patients (4.2%), with nine cases in group A, 10 in group B and 30 in group C. Re-operation was required in 21/49 (42.8%) cases, and in seven of these the last i-PTH concentration was >or=500 pg/ml. All cases in group A required re-operation. In group C, 11/30 (36.7%) patients required re-operation. The missed glands removed at re-operation were supernumerary in 14 cases, and located in the mediastinum in 13 cases. The frequency of advanced HPT and re-operation was not negligible.
[EX A]:
Is re-operation frequently required when parathyroid glands remain after initial parathyroidectomy for advanced secondary hyperparathyroidism in uraemic patients?