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:
It is well established that African Americans (AA) experience greater pain associated with a variety of clinical conditions, and greater pain sensitivity to experimental pain tasks relative to non-Hispanic Whites (W). Notably, African Americans do not show the same relationships involving endogenous pain regulatory mechanisms and pain sensitivity documented in Caucasians, including positive associations between blood pressure, norepinephrine, cortisol and greater pain tolerance.', 'The purpose of this study was to examine the relationship between plasma oxytocin (OT) and pain sensitivity and to explore the relation of OT to other factors known to influence pain perception.', 'OT concentration and sensitivity to ischemic, cold pressor, and thermal pain tasks were assessed in African American (n=25) and non-Hispanic White (n=23) pre-menopausal women.', 'African American women demonstrated significantly lower pain tolerance across tasks compared with Whites (F(1,46)=6.31, p=0.0156) and also exhibited lower plasma OT levels (AA: 3.90, W: 7.05 pg/mL; p=0.0014). Greater OT levels were correlated with greater tolerance to ischemic pain (r=0.36, p=0.013) and accounted for a marginally significant portion of the ethnic difference in ischemic pain tolerance (B=+0.29, p=0.06). Greater OT was also correlated with greater tolerance of cold pressor pain (r=0.31, p=0.03); however, this association was no longer seen after the variance due to ethnicity was accounted for.
answer:
Is ethnicity associated with alterations in oxytocin relationships to pain sensitivity in women?


question:
To correlate cerebral cavernous malformations (CCMs) disease aggressiveness with peripheral blood biomarkers hypothesized mechanistically.', 'A prospective case-control study enrolled 43 CCM patients, where 25-(OH) vitamin D, HDL and non-HDL cholesterol, CRP plasma levels and leukocyte ROCK activity were correlated with parameters of disease aggressiveness reflecting chronic and acute domains.', 'Patients with one or more features of chronically aggressive disease (early age at symptom onset, two or more symptomatic bleeds, high lesion burden) had significantly lower 25-(OH) vitamin D and non-HDL cholesterol levels in comparison to patients without these features.
answer:
Do peripheral plasma vitamin D and non-HDL cholesterol reflect the severity of cerebral cavernous malformation disease?


question:
Critical recurrences after radiofrequency ablation for hepatocellular carcinoma (HCC), such as intrahepatic metastases or dissemination, and extrahepatic metastases or seeding, which are difficult to treat radically, almost certainly lead to primary cancer death. The present study aimed to clarify whether the arterial tumor enhancement pattern on contrast-enhanced computed tomography (CECT) is associated with critical recurrence and cancer death after RFA for small HCC.', 'Between April 2001 and September 2011, 226 patients with initial small hypervascular HCC (≤3 cm in diameter and ≤3 tumors) were treated by RFA. Arterial tumor enhancement patterns on CECT before RFA were categorized by whether non-enhanced areas were included inside the tumor stain.', 'The heterogeneous enhancement group included 44 patients, and the homogeneous enhancement group included 182 patients. The cumulative 5-year critical recurrence rates of the heterogeneous and homogeneous enhancement groups were 42 and 22% (p = 0.005), respectively. Univariate analysis for factors related to critical recurrence showed significant differences in sex, arterial enhancement pattern, and response to antiviral therapy. These factors were independent on multivariate analysis. The cumulative 5-year primary cancer death rates of the heterogeneous and homogeneous enhancement groups were 29 and 13% (p = 0.002), respectively. Univariate analysis for factors related to primary cancer death showed significant differences in arterial enhancement pattern and response to antiviral therapy. These factors were independent on multivariate analysis.
answer:

Is the arterial tumor enhancement pattern on contrast-enhanced computed tomography associated with primary cancer death after radiofrequency ablation for small hepatocellular carcinoma?