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.
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Question: To investigate the influence of metabolic syndrome on prostate-specific antigen levels by considering prostate volume and plasma volume.', 'We retrospectively analyzed 4111 men who underwent routine check-ups including prostate-specific antigen and transrectal ultrasonography. The definition of metabolic syndrome was based on the modified Adult Treatment Panel III criteria. Prostate-specific antigen mass density (prostate-specific antigen × plasma volume / prostate volume) was calculated for adjusting plasma volume and prostate volume. We compared prostate-specific antigen and prostate-specific antigen mass density levels of participants with metabolic syndrome (metabolic syndrome group, n = 1242) and without metabolic syndrome (non-prostate-specific antigen metabolic syndrome group, n = 2869). To evaluate the impact of metabolic syndrome on prostate-specific antigen, linear regression analysis for the natural logarithm of prostate-specific antigen was used.', 'Patients in the metabolic syndrome group had significantly older age (P < 0.001), larger prostate volume (P < 0.001), higher plasma volume (P < 0.001) and lower mean serum prostate-specific antigen (non-metabolic syndrome group vs metabolic syndrome group; 1.22 ± 0.91 vs 1.15 ± 0.76 ng/mL, P = 0.006). Prostate-specific antigen mass density in the metabolic syndrome group was still significantly lower than that in the metabolic syndrome group (0.124 ± 0.084 vs 0.115 ± 0.071 μg/mL, P = 0.001). After adjusting for age, prostate volume and plasma volume using linear regression model, the presence of metabolic syndrome was a significant independent factor for lower prostate-specific antigen (prostate-specific antigen decrease by 4.1%, P = 0.046).

Answer: Is prostate-specific antigen lowering effect of metabolic syndrome influenced by prostate volume?


Question: 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.

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


Question: Injection drug users (IDUs) are at risk of acquiring HIV through injection and sexual practices.', 'We analyzed data collected in five U.S. cities between 2002 and 2004 to identify correlates of HIV infection among 3285 IDUs ages 15-30 years.', 'Overall, HIV prevalence was 2.8% (95% CI 2.3-3.4), ranging from 0.8% in Chicago to 6.3% in Los Angeles. Mean age was 24 years, 70% were male, 64% non-Hispanic (NH) white, 7% NH black, 17% Hispanic, and 12% were other/mixed race. HIV infection was independently associated with: race/ethnicity (NH black [AOR 4.1, 95% CI 1.9-9.1], Hispanic [AOR 3.6, 95% CI 1.5-8.4], or other/mixed [AOR 2.3, 95% CI 1.1-5.2] vs. NH white); males who only had sex with males compared to males who only had sex with females (AOR 15.3, 95% CI 6.8-34.5); injecting methamphetamine alone or with heroin compared to heroin only (AOR 4.0, 95% CI 1.7-9.7); reporting inconsistent means of obtaining income compared to regular jobs (AOR 2.3, 95% CI 1.1-4.8); and having a history of exchanging sex for money/drugs (AOR 2.8, 95% CI 1.5-5.2).

Answer:
Do young adult injection drug users in the United States continue to practice HIV risk behaviors?