instruction:
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.
question:
The aim of this study was to determine the reasons for which erupted third molars (3M) are extracted in a sample of Mexican patients.', "A retrospective cross-sectional study was performed on a sample of 83 patients attending exodontia (minor oral surgery) clinics of a public university in Mexico (Autonomous University of Hidalgo State). The outcome variable was the reason for extractions using Kay and Blinkhorn's classification. The independent variables were age, gender, arch and tooth number according to the World Health Organization (WHO). For statistical analysis, we used the Chi-squared test in Stata 9.0.", 'Eighty-three patients underwent 150 3M extractions. Mean age was 38.67 ± 13.96 years, and 71.1% were female. The four reasons for 3M extraction were prosthetic (44.0%), followed by orthodontic (24.7%), dental caries (20.0%) and periodontal disease (11.3%). Differences were observed in the reasons for 3M extractions across age groups (p < 0.05). No significant differences existed between men and women (p > 0.05), or the WHO tooth number (p > 0.05).
answer:
Are reasons why erupted third molars extracted in a public university in Mexico?


question:
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.
answer:
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?


question:
Calcium channel blockers (CCBs) inhibit the migration of vascular smooth muscle cells (VSMC) by mechanisms that remain poorly understood. The purpose of the present study was to characterize the signaling mechanisms by which CCBs inhibit VSMC migration.', 'Nifedipine potently inhibited platelet-derived growth factor (PDGF)-induced chemotaxis, collagen I-induced haptotaxis, and wound-induced migration of human aortic VSMC. In addition, nifedipine inhibited PDGF-induced membrane ruffling and lamellipodium formation. PDGF-induced VSMC migration was significantly inhibited by PP2, a selective inhibitor of the Src kinase family, and was also significantly inhibited by the expression of kinase-inactive Src, suggesting that Src is required for VSMC migration. Nifedipine also inhibited PDGF-induced Src activation (by 60+/-4% with 30 microM) and tyrosinephosphorylation of Cas, paxillin, and cortactin, which are actin-associated substrates of Src. RNA interference-induced knockdown of the Ca(2+)-dependent tyrosine kinase, Pyk2, resulted in inhibition of PDGF-induced Src activation and migration. Finally, nifedipine inhibited PDGF-induced Pyk2 activation in a dose-dependent manner.
answer:

Does nifedipine interfere with migration of vascular smooth muscle cells via inhibition of Pyk2-Src axis?