TASK DEFINITION: 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.
PROBLEM: Context: Macroprolactinemia is a frequent finding in hyperprolactinemic individuals, usually without clinical impact. Data on biological activity of macroprolactin (bbPRL) are controversial and mostly based on a heterologous rat Nb2 cell bioassay. Biological activity of bbPRL observed in vitro but not in vivo may be due to its high molecular weight, preventing its passage through capillary barrier. Alternatively, bbPRL bioactivity may differ depending on the prolactin (PRL) receptor (PRLR) species specificity.', 'The objective of the study was to characterize the bioactivity of bbPRL in a homologous bioassay: Ba/F-3 cells stably expressing the human PRLR.', "Chromatography-purified bbPRL from macroprolactinemic individuals (group I, n = 18) and monomeric PRL from hyperprolactinemic patients without macroprolactinemia (group II, n = 5) were tested in Nb2 and Ba/F-LLP bioassays. Both groups were followed up at the neuroendocrinology outpatients' clinic.", 'Biological activity of bbPRL presented in the two bioassays was measured.', 'In group I, no patient had hypogonadism. Mean ratio bioactivity to immunoactivity of bbPRL in the Nb2 assay was 0.69. There was no dose-response in 15 of the 18 samples tested in Ba/F-LLP assay. In group II, three patients had galactorrhea and all five had hypogonadism. Mean ratio bioactivity to immunoactivity of monomeric PRL samples was 1.35 in Nb2 and 0.91 in Ba/F-LLP assay.
Answer: Whereas both bioassays achieve similar results with respect to monomeric PRL activity, our results indicate that the activity displayed by bbPRL toward the rat receptor may be inappropriate because it is not observed in the human PRLR-mediated assay, consistent with the apparent absence of bioactivity in vivo.

SOLUTION: Does human macroprolactin display low biological activity via its homologous receptor in a new sensitive bioassay?

PROBLEM: Context: Associations between multidrug resistance and the Mycobacterium tuberculosis Beijing genotype have been described mainly in populations with poor tuberculosis (TB) control such as prisons and inner cities, and may reflect shared risk factors rather than a biological association.', 'To study the association between genotype and drug resistance among TB patients in a population with adequate TB control.', 'Three rural districts in Vietnam. The study was performed at the Pham Ngoc Thach Tuberculosis and Lung Disease Hospital, Ho Chi Minh City, and the Tien Giang Provincial Tuberculosis and Lung Disease Hospital, My Tho, Vietnam.', 'Pretreatment sputum specimens were collected for culture, drug susceptibility testing and spoligotyping of all sputum smear-positive pulmonary TB patients consecutively diagnosed over a 3-year period.', 'Beijing genotype infections were observed in 614 of 1744 (35%) patients. Beijing strains were more common among female (adjusted odds ratio [aOR] 1.4, P = 0.005), young (aOR 2.8, P < 0.001) and previously treated patients (aOR 2.4, P < 0.001). The Beijing genotype was associated with any resistance (aOR 3.7, P < 0.001) and multidrug resistance (aOR 6.8, P < 0.001) among new patients, and with any resistance (aOR 2.7, P = 0.005) but not with multidrug resistance (aOR 1.4, P = 0.545) among previously treated patients.
Answer: In Vietnam, Beijing genotype is associated with young age and in new patients with multidrug resistance despite adequate TB control, suggesting a biological association. This potentially undermines the effectiveness of TB control in countries where Beijing genotype infections are common.

SOLUTION: Is the Beijing genotype associated with young age and multidrug-resistant tuberculosis in rural Vietnam?

PROBLEM: Context: To reduce cholangitis after pancreaticoduodenectomy (PD), we perform 'hepaticoplasty', in which the left side of the bile duct is cut to widen the diameter of the bile duct wall before hepaticojejunostomy. The aim of this study was to clarify the usefulness of hepaticoplasty to reduce cholangitis after PD.", 'From January 2002 through December 2010, 161 patients underwent PD and were enrolled in this study. Patient demographics, surgical factors, and clinical and biochemical parameters were evaluated to examine the factors predictive of cholangitis after PD and confirm the usefulness of hepaticoplasty.', 'Cholangitis after PD occurred in 13 patients (8.1%). Multivariate analysis revealed that the ratio of the postoperative bile duct diameter to that before surgery was the only independent risk factor for cholangitis after PD (p\xa0=\xa00.0012). In the small bile duct group, in which the diameter was ≤15\xa0mm before surgery (n\xa0=\xa099), hepaticoplasty reduced the narrowing of the bile duct after PD, and no cholangitis occurred. There were no complications related to hepaticoplasty.
Answer: The ratio of postoperative reduction of the bile duct diameter to that before surgery was found to be the only risk factor for cholangitis after PD. Patients with a small bile duct of ≤15 mm in diameter preoperatively might benefit from hepaticoplasty to widen the bile duct diameter and prevent cholangitis after PD.

SOLUTION:
Does hepaticoplasty prevent cholangitis after pancreaticoduodenectomy in patients with small bile ducts?