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.

Q: Context: Food atopy patch tests (APTs) are considered a useful tool for the diagnosis of food allergy. Hypersensitivity to peanuts has not been investigated by means of APTs so far.', 'APTs and skin prick tests (SPTs) with peanuts were performed in 136 atopic dermatitis (AD) patients. Relevance of positive and negative responses to these tests was assessed by repeated open challenges with peanuts.', 'Nine percent of our AD patients reacted to the challenge. Positive responses to APTs were recorded in 19% of the patients, whereas in 12% positive SPTs were observed. APTs were more frequently positive in subjects with eczematous responses after challenge with respect to those with urticarial reactions. SPT reactivity proved to be higher in patients above 12 years of age, whereas APT positivity was more frequent in children under 6 years. APT sensitivity proved significantly higher than SPT sensitivity, in particular in children under 12 years of age. On the contrary, SPT specificity and positive predictive value were significantly higher with respect to those of APT in the age group of subjects under 6 years of age.
Answer: Our data suggest that APTs with peanuts may represent a useful integration to standard testing modalities employed for the diagnosis of peanut allergy in AD patients.

A: Does combined skin prick and patch testing enhance identification of peanut-allergic patients with atopic dermatitis?
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Q: Context: Anemia is an established adverse risk factor in cardiovascular disease. However, the effect of preoperative anemia is not well defined in heart surgery. This study evaluates the effect of preoperative anemia on early clinical outcomes in patients undergoing cardiac surgery.', 'A retrospective, observational, cohort study of prospectively collected data was undertaken on 7,738 consecutive patients undergoing heart surgery between April 2003 and February 2009. Of these, 1,856 patients with preoperative anemia were compared to 5,882 patients without anemia (control group). According to the World Health Organization, anemia was defined as hemoglobin level<13 g/dl for men and <12 g/dl for women. Selection bias not controlled by multivariable methods was assessed with propensity-adjustment method.', 'Overall mortality was 2.1%. Preoperative anemia was associated with tripling in the risk of death (4.6% vs 1.5%, p<0.0001) and postoperative renal dysfunction (18.5% vs 6.5%, p<0.0001). There was also a significant difference between the anemic and non-anemic group in the risk of postoperative stroke (1.9% vs 1.1%, p=0.008), atrial fibrillation (36.7% vs 33%, p=0.003) and length of hospital stay>7 days (54% vs 36.7%, p<0.0001). In propensity-adjusted, multivariable logistic regression, preoperative anemia was an independent predictor of mortality (odds ratio [OR] 1.44, 95% confidence interval [CI] 1.02 to 2.03), postoperative renal dysfunction (OR 1.73, 95% CI 1.43 to 2.1) and length of hospital stay>7 days (OR 1.3, 95% CI 1.15 to 1.47).
Answer: In patients undergoing heart surgery, preoperative anemia is associated with an increased risk of mortality and postoperative morbidity.

A: Does preoperative anemia increase mortality and postoperative morbidity after cardiac surgery?
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Q: Context: Recurrence after surgery for secondary hyperparathyroidism is not infrequent. Regrowth of the residual parathyroid tissue after subtotal parathyroidectomy or of the autograft after total parathyroidectomy occurs in many cases. Supernumerary glands are also frequently cited as the offending cause and upon revisiting the neck, the surgeon may be surprised that such an obvious gland was 'missed' at the first operation. Indeed, multiple glands removed in sequential operations have been reported suggesting that they develop over time rather than being present from the start. It is possible that microscopic parathyroid 'rests' of embryological origin proliferate under the ongoing stimulus of renal failure to produce supernumerary glands after apparently adequate initial surgery for hyperparathyroidism. The aim of the present study was to determine whether such rests occur frequently or infrequently.", 'Operative details and pathology results from 60 consecutive parathyroidectomies were reviewed and the occurrence of parathyroid rests noted.', 'Parathyroid rests were found in 37% of extra parathyroidal tissues submitted for analysis. These rests were found commonly in the thymus. The potential significance of such parathyroid rests undergoing hyperplasia in response to the ongoing stimulus of renal failure and leading to recurrent hyperparathyroidism is discussed.
Answer: Parathyroid rests are common and potentially serve as a cause of recurrent disease in secondary hyperparathyroidism. Consideration should be given to performing thymectomy as part of the treatment of secondary hyperparathyroidism. A more detailed study is warranted.

A:
Does embryonic parathyroid rest occur commonly and have implications in the management of secondary hyperparathyroidism?
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