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 vascular endothelial growth factor (VEGF) family and VEGF receptors (VEGFR) play an essential role in the angiogenesis of both pathologic and nonpathologic conditions. However, the prognostic significance of VEGF and VEGFR expression in ovarian carcinoma is unclear.', 'The tissue expression levels of VEGF-A, VEGF-C, VEGFR-2, and VEGFR-3 in 80 specimens of ovarian carcinoma were examined immnohistochemically. The results obtained were analyzed clinicopathologically.', 'VEGF-A, VEGF-C, VEGFR-2, and VEGFR-3 were expressed both in tumor cells and in adjacent endothelial cells of blood and lymph vessels. The tissue expressions of VEGF-C and VEGFR-2 were correlated significantly with tumor extension, including peritoneal metastases outside the pelvic cavity (P = 0.0010 and P = 0.0008, respectively), lymph node metastases (P = 0.0030 and P = 0.0018, respectively), and positive ascitic cytology (P = 0.025 and P = 0.0016, respectively). Conversely, there was no significant correlation between VEGF-A and VEGFR-3 expression and clinicopathologic features of ovarian carcinoma. Logistic regression analysis revealed that the expressions of VEGF-C and VEGFR-2 also were independent risk factors for peritoneal and lymph node metastases. Survival curves determined by the Kaplan-Meier method and in univariate analysis demonstrated that high expression levels of VEGF-C and VEGFR-2 were associated with the 5-year survival rate. In multivariate analysis, high expression levels of VEGF-C and VEGFR-2 emerged as independent indicators for disease-specific survival.
answer:
Are vascular endothelial growth factor C and vascular endothelial growth factor receptor 2 related closely to the prognosis of patients with ovarian carcinoma?

question:
This study investigated whether a 7-week yoga intervention could improve physical function, perceived stress, and mental/emotional wellness in elderly participants.', '8 participants (66.50.3 years) attended 2 60-min Hatha yoga sessions/week for 7 weeks, and performed pre- and post-intervention assessments. Balance was assessed using a 5-test battery. Flexibility was measured by sit-and-reach and shoulder flexibility tests. Functional mobility tests included 8-ft up-and-go, 5 chair stands, and 4-m walk. Participants completed SF-12, exhaustion level, and Perceived Stress Scale (PSS) questionnaires.', 'SF-12 Mental Component Summary scores, exhaustion levels, and PSS scores improved post-intervention. No differences were found for physical function measures.
answer:
Does yoga reduce perceived stress and exhaustion levels in healthy elderly individuals?

question:
To explore whether the prevalence and severity of retinopathy differ in diabetes cohorts diagnosed through screening as compared with conventional health care.', 'A total of 257 diabetes patients, 151 detected through screening and 106 through conventional clinical care, were included. Retinopathy was evaluated by fundus photography. The modified Airlie House adaptation of the Early Treatment Retinopathy Study protocol was used to grade the photographs. Averages of clinically collected fasting blood glucose (FBG), blood pressure and body mass index values were compiled from diabetes diagnosis until the eye examination. Blood chemistry, smoking habits and peripheral neuropathy were assessed at the time of the eye examination.', "Among the screening-detected patients, 22% had retinopathy as compared to 51% among those clinically detected (p < 0.0001). In a multivariate analysis, patients with retinopathy were more likely to have increased average FBG (OR 1.42, 95% CI 1.19-1.70 per mmol/l) and peripheral neuropathy (OR 2.75, 95% CI 1.40-5.43), but less likely to have screening-detected diabetes (OR 0.31, 95% CI 0.17-0.57). Similar results were found using increasing severity grade of retinopathy as outcome. The cumulative retinopathy prevalence for the screening-detected diabetes cohort as compared with the clinically diagnosed cohort was significantly lower from 10 years' follow-up and onwards (p = 0.0002).
answer:
Are early detection of type 2 diabetes mellitus and screening for retinopathy associated with reduced prevalence and severity of retinopathy?