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 Input:
Formation of branching tubes is a fundamental step in the development of glandular organs. To identify extracellular cues that orchestrate epithelial tubulogenesis, we employed an in vitro assay in which EpH4-J3B1A mammary epithelial cells form spheroidal cysts when grown in collagen gels under serum-free conditions, but form branching tubules in the presence of fetal calf serum (FCS).', 'Initial experiments showed that the tubulogenesis-inducing activity of FCS was markedly increased by heating (70 degrees C) or transient acidification to pH3. We therefore hypothesized that the tubulogenic agent was transforming growth factor-beta (TGF-beta), a cytokine that is present in serum in latent form and can be activated by heat or acid treatment. We found indeed that the tubulogenic activity of acidified FCS is abrogated by addition of either SB-431542, a selective inhibitor of the TGF-beta type I receptor, or a neutralizing antibody to TGF-beta-1. On the other hand, addition of low concentrations (20-100 pg/ml) of exogenous TGF-beta-1 recapitulated the effect of acidified FCS in inducing morphogenesis of hollow tubes. In contrast, higher concentrations of TGF-beta-1 induced the formation of thin cellular cords devoid of a detectable lumen. To gain insight into the mechanisms underlying TGF-beta-1-induced tube formation, we assessed the potential role of matrix metalloproteinases (MMPs). By western blot and gelatin zymography, we observed a dose-dependent increase in MMP-9 upon TGF-beta-1 treatment. Tube formation was suppressed by a synthetic broad-spectrum metalloproteinase inhibitor, by recombinant tissue inhibitor of metalloproteinases-2 (TIMP-2) and by a selective inhibitor of MMP-9, indicating that this morphogenetic process requires the activity of MMP-9.

Ex Output:
Do low concentrations of transforming growth factor-beta-1 induce tubulogenesis in cultured mammary epithelial cells?

Ex Input:
To examine the relationship between sperm strict morphology and sperm chromatin integrity.', 'Prospective study.', 'Infertility clinic.', 'Eighty-seven consecutive semen samples from non-azoospermic men presenting for infertility evaluation and 6 samples from fertile donors.', 'Assessment of standard semen parameters and sperm chromatin structure assay (SCSA) parameters (%DFI [DNA fragmentation index] and %HDS [high DNA stainability]). Evaluation of %HDS and %DFI after treatment with dithiothreitol (a thiol-reducing agent used to decondense sperm nuclei) was also undertaken.', 'Relationship between sperm strict morphology defects and SCSA parameters (%DFI and %HDS).', 'We observed significant relationships between the percentage of normal sperm forms and both %HDS (r = -0.40) and sperm motility (r = 0.32). We also found significant relationships between sperm head defects and both %HDS (r = 0.40) and sperm concentration (r = -0.39). Sperm tail, midpiece, and neck defects were not significantly related to the SCSA parameters. Treatment of spermatozoa with dithiothreitol (to induce decondensation) resulted in a substantial increase in %HDS but no measurable change in %DFI.

Ex Output:
Is sperm head morphology related to high deoxyribonucleic acid stainability assessed by sperm chromatin structure assay?

Ex Input:
The purpose of the study was to determine whether racial differences exist in the pattern of local disease progression among men treated with radical prostatectomy (RP) for localized prostate cancer (PCa), which is currently unknown. In this study we evaluated the pattern of adverse pathologic features in an identical cohort of African-American (AA) and Caucasian (CS) men with PCa.', 'The overall cohort consisted of 1104 men (224 AA, and 880 CS) who underwent RP between 1990 and 2012. We compared preoperative factors and pathologic outcomes after RP across race groups. Multivariate analysis was used to identify factors predictive of adverse pathologic outcomes. The effect of race on adverse pathologic outcomes and biochemical control rate (BCR) was evaluated using multivariate regression model and Kaplan-Meier analysis.', 'The 10-year BCR was 59% versus 82% in AA and CS men, respectively (P = .003). There was no significant difference in extraprostatic spread (P = .14), positive surgical margin (P = .81), lymph node involvement (P = .71), or adverse pathologic features (P = .16) across race groups. However, among patients with 1 adverse pathologic features, AA men had higher rate of seminal vesicle invasion (SVI) compared with CS men (51% vs. 30%; P = .01). After adjusting for known predictors of adverse pathologic features AA race remained a predictor of SVI.

Ex Output:
Is african-american race a predictor of seminal vesicle invasion after radical prostatectomy?