In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[Q]: Context: Profiles of allergic sensitization are poorly documented in infancy. Relations between early sensitization and allergic morbidity need to be clarified.', 'This study dealt with children involved in the Pollution and Asthma Risk: an Infant Study (PARIS), a population-based prospective birth cohort. Allergic sensitization to twelve food and four inhalant allergens was assessed at 18\xa0months and defined by a specific immunoglobulin E (IgE) level ≥0.35\xa0kU', 'Sensitization to any allergen concerned 13.6% of infants. By cluster analysis, 1525 infants were grouped into three profiles: 89.2% not or rarely sensitized (only 3.7% of sensitized), 9.2% mainly sensitized to one or few allergens (45.2% of monosensitized and 45.9% of paucisensitized) and 1.6% all polysensitized. The prevalence of doctor-diagnosed asthma, rhinitis, eczema, food allergy and multimorbidity at 2\xa0years increased from profile one to profile three (p-trend <0.001). At 6\xa0years, symptoms of current asthma, rhinitis, eczema and multimorbidity were significantly more frequent in the last two profiles.\Question: Is early polysensitization associated with allergic multimorbidity in PARIS birth cohort infants?
[A]: This study highlights, as early as 18 months of age, three profiles of increasing severity with regard to allergic sensitization and diseases. These profiles also differ in terms of allergic morbidity at 6 years. Early sensitization can predict allergic multimorbidity in childhood, and in the case of early polysensitization, multimorbidity is more frequent as soon as infancy.


[Q]: Context: Eradication of Helicobacter pylori is not routinely recommended for the symptomatic relief and the prevention of gastric cancer in patients with functional dyspepsia. The present study investigated a useful indicator of H. pylori eradication in such patients by determining the optimal cutoff value of a 13C-urea breath test (UBT).', 'One hundred dyspeptic patients participated in the study. Dyspepsia was scored, and a 13C-UBT administered. A level of delta 13C-UBT of>4 per thousand was diagnosed as H. pylori-positive. After the stomach was endoscopically sprayed with phenol red, biopsy specimens were taken from the antrum, body and cardia of the stomach for the assessment of H. pylori density, and activity (neutrophil infiltration) and degree (lymphocyte infiltration) of gastritis.', 'Correlation between delta 13C-UBT and dyspepsia score was not found. Delta 13C-UBT significantly correlated with H. pylori density score in the total stomach (r = 0.53, P < 0.0001), neutrophil (r = 0.34, P = 0.0005) and lymphocyte score (r = 0.69, P < 0.0001). Twenty-six of the 100 subjects had a neutrophil score of >or=4, lymphocyte score of >or=4, and H. pylori score of >or=4. Their 95% confidence interval of mean was 58.2 per thousand, which reflects moderate to marked acute and chronic gastritis, and dense H. pylori colonization.\Question: Is delta ( 13 ) C-urea breath test value a useful indicator for Helicobacter pylori eradication in patients with functional dyspepsia?
[A]: The 13C-UBT is a reliable semiquantitative test to assess H. pylori density and the activity and degree of gastritis. It is proposed that H. pylori eradication therapy might be beneficial for patients with functional dyspepsia with a delta 13C-UBT of >58.2 per thousand.


[Q]: Context: It has been recognized for almost a decade that concentrations of signaling androgens sufficient to activate the androgen receptor are present in castration-resistant prostate cancer tissue. The source of these androgens is highly controversial, with three competing models proposed. We, therefore, wished to determine the androgenic potential of human benign and malignant (hormone-naïve and treated) prostate tissue when incubated with various precursors and examine concomitant changes in enzyme expression.', 'Freshly harvested prostate tissue [benign, hormone-naïve, and hormone-refractory prostate cancer (HRPC)] was incubated in excess concentrations of cholesterol, progesterone, DHEA, androstenedione, or testosterone for 96 hours, and steroid concentrations in the conditioned media measured by gas chromatography-mass spectroscopy. Changes in the expression of androgen synthetic and/or degradative enzymes were determined by expression microarray and qPCR. Significant changes were confirmed in an independent dataset.', 'Of the precursor molecules tested, only incubation with androstenedione gave rise to significant concentrations of signaling androgens. Although this was observed in all tissue types, it occurred to a significantly greater degree in hormone-refractory compared with hormone-naïve cancer. Consistent with this, gene set enrichment analysis of the expression microarray data revealed significant upregulation of 17HSD17B activity, with overexpression of the canonical enzyme AKR1C3 confirmed by qPCR in the same samples and in a publicly available expression dataset. Importantly, we found no evidence to support a significant contribution from either the "backdoor" or "5-α dione" pathway.\Question: Is canonical androstenedione reduction the predominant source of signaling androgens in hormone-refractory prostate cancer?
[A]:
Reduction of androstenedione to testosterone by the canonical HSD17B AKR1C3 is the predominant source of signaling androgens in HRPC.