In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[EX Q]: Context: Carotid stiffening is considered a key element in the pathogenesis of stroke. However, results of studies evaluating the association between carotid stiffness and incident stroke have been inconsistent.', 'This study investigated whether carotid stiffness (as determined by ultrasonography) is associated with incident stroke and whether this association is independent of aortic stiffness as estimated by carotid-femoral pulse wave velocity (cfPWV). Additionally, we evaluated the incremental value of carotid stiffness for stroke risk prediction beyond Framingham risk factors and cfPWV.', 'This study included a systematic review and meta-analyses of aggregate and individual participant data (IPD), the latter of which was obtained by requesting individual-level data of all cohort studies with available data on carotid stiffness and cfPWV.', 'Ten studies (n= 22,472) were included in the aggregate data meta-analysis and 4 (n= 4,540) in the IPD meta-analysis. After adjusting for cardiovascular (CV) factors, the aggregate data meta-analysis showed that greater carotid stiffness (per SD) was associated with stroke (hazard ratio: 1.18; 95% confidence interval: 1.05 to 1.33). In addition, carotid stiffness was associated with total CV events and CV and all-cause mortality, but not with coronary heart disease events. In the IPD meta-analysis, additional adjustment for cfPWV did not materially change these associations. Carotid stiffness did improve stroke risk prediction beyond Framingham and cfPWV (integrative discrimination improvement: 0.4 percentage point [95% confidence interval: 0.1 to 0.6 percentage point] and continuous net reclassification improvement: 18.6% [95% confidence interval: 5.8% to 31.3%]).\Question: Is carotid stiffness associated with incident stroke : a systematic review and individual participant data meta-analysis?
[EX A]: Carotid stiffness is associated with incident stroke independently of CV factors and aortic stiffness. Inaddition, carotid stiffness improves stroke risk prediction beyond Framingham and aortic stiffness.

[EX Q]: Context: To determine whether testosterone levels change as women with the polycystic ovary syndrome (PCOS) grow older.', 'A follow-up cross-sectional study of a cohort of women with PCOS identified up to 20-25 years ago.', 'Women with PCOS were recruited primarily from practice records between 1970 and 1990. Voter registration tapes and household directories were used to identify age-, race-, and neighborhood-matched controls.', 'Eighty-four women with PCOS, 20-57 years of age, and 37 age-matched controls participating in a study of the risk for cardiovascular disease in women with PCOS.', 'Clinical data were collected by questionnaire and fasting blood samples were obtained randomly throughout the menstrual cycle.', 'Total and non-SHBG-bound testosterone levels.', 'Total and non-SHBG-bound testosterone levels were similar in women with PCOS who were 20-42 years of age but were reduced by approximately 50% among women 42-47 years of age and remained stable in women older than 47 years of age. Testosterone levels were increased in younger and older women with PCOS compared with controls but were similar to controls in women 42-47 years of age.\Question: Do serum testosterone levels decrease in middle age in women with the polycystic ovary syndrome?
[EX A]: Hyperandrogenism partly resolves before menopause in women with PCOS. This change may explain the tendency of women with PCOS to cycle regularly as they grow older. Testosterone levels remain elevated in older women with PCOS, however, and may contribute to their increased risk for cardiovascular disease, endometrial cancer, and other diseases.

[EX Q]: Context: Enhancing thrombus resolution may reduce the long-term complications of venous thrombosis. The aim of this study was to examine whether a sustained release of vascular endothelial growth factor (VEGF) would further improve thrombus recanalization.', 'Inferior caval vein thrombosis was induced in a cohort of 21 male Wistar rats. A plasmid encoding the human VEGF gene (phVEGF) was injected directly into thrombus (30 to 50 microg) and the muscle adjacent to the inferior vena cava (300 to 400 microg). A plasmid containing the gene encoding beta-galactosidase (pCMVbeta) was injected into the same sites of a separate cohort of rats to act as a control. Tissues were harvested after 1 and 2 weeks, and beta-galactosidase activity was measured to estimate transfection efficiency. Muscle and serum VEGF were measured by enzyme-inked immunosorbent assay. Thrombus size, recanalization, and organization were determined by computer-assisted image analysis.', 'The efficiency of control plasmid transfection into muscle was about 1%. No serum hVEGF was detected in phVEGF- or pCMVbeta-treated animals. Significantly raised levels of hVEGF (P < .01) were detected in the muscle injected with phVEGF after 2 weeks compared with control muscle. There was a significant reduction in thrombus size of 23% (P < .05) and 48% (P < .001) in phVEGF-treated animals compared with pCMVbeta-treated controls after 1 and 2 weeks, respectively. Thrombus recanalization was a significantly greater in the phVEGF-treated group after 2 weeks (mean 19% +/- 2% [SEM]) compared with controls (mean 13% +/- 2%, P < .01). There were no differences in the thrombus organization score.\Question: Does vascular endothelial growth factor naked DNA gene transfer enhance thrombus recanalization and resolution?
[EX A]:
VEGF gene therapy of venous thrombus resulted in smaller thrombi with greater recanalization. Angiogenic gene therapy may form the basis of a novel treatment that may improve the resolution of venous thrombi.