Given a passage with a context and an answer, 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.

Q: Context: Alterations in epigenetic processes are frequently noted in human disease. These epigenetic processes involve methylation of DNA and post-translational modifications of histones. It is well established that in particular histone methylation plays a key role in gene transcription. In this study, we have investigated the relationship between triple methylation of lysine 27 in histone H3 (H3K27Me3) modifications and atherosclerotic plaque stage.', '28 peri-renal aortic tissue patches covering the entire spectrum of atherosclerotic plaque development were evaluated by immunohistochemistry for the levels of H3K27Me3, EZH2, JMJD3 and BMI1.', 'The results of our studies are in support of a reduction in global levels of the H3K27Me3 modification in vessels with advanced atherosclerotic plaques. This reduction in H3K27Me3 levels is not accompanied by alterations in global levels of the corresponding histone methyltransferase EZH2, the catalytic subunit of the polycomb repressive complex 2 (PRC2). Likewise no alterations in global levels of BMI1, a component of the PRC1 complex, which binds to H3K27Me3-modified histones or the global expression levels of the histone demethylase JMJD3, which removes the methyl marks on H3K27, were observed.
Answer: Together, our data show that in atherosclerosis development alterations in global levels of H3K27Me3 occur. The reduction in the number of nuclei in the tunica media that display the repressive H3K27Me3 mark in vessels with advanced atherosclerosis plaques therefore could be a reflection of the dynamic pattern of smooth muscle cell differentiation and proliferation associated with atherosclerotic disease.

A: Are global histone H3 lysine 27 triple methylation levels reduced in vessels with advanced atherosclerotic plaques?
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Q: Context: Anemia is an established adverse risk factor in cardiovascular disease. However, the effect of preoperative anemia is not well defined in heart surgery. This study evaluates the effect of preoperative anemia on early clinical outcomes in patients undergoing cardiac surgery.', 'A retrospective, observational, cohort study of prospectively collected data was undertaken on 7,738 consecutive patients undergoing heart surgery between April 2003 and February 2009. Of these, 1,856 patients with preoperative anemia were compared to 5,882 patients without anemia (control group). According to the World Health Organization, anemia was defined as hemoglobin level<13 g/dl for men and <12 g/dl for women. Selection bias not controlled by multivariable methods was assessed with propensity-adjustment method.', 'Overall mortality was 2.1%. Preoperative anemia was associated with tripling in the risk of death (4.6% vs 1.5%, p<0.0001) and postoperative renal dysfunction (18.5% vs 6.5%, p<0.0001). There was also a significant difference between the anemic and non-anemic group in the risk of postoperative stroke (1.9% vs 1.1%, p=0.008), atrial fibrillation (36.7% vs 33%, p=0.003) and length of hospital stay>7 days (54% vs 36.7%, p<0.0001). In propensity-adjusted, multivariable logistic regression, preoperative anemia was an independent predictor of mortality (odds ratio [OR] 1.44, 95% confidence interval [CI] 1.02 to 2.03), postoperative renal dysfunction (OR 1.73, 95% CI 1.43 to 2.1) and length of hospital stay>7 days (OR 1.3, 95% CI 1.15 to 1.47).
Answer: In patients undergoing heart surgery, preoperative anemia is associated with an increased risk of mortality and postoperative morbidity.

A: Does preoperative anemia increase mortality and postoperative morbidity after cardiac surgery?
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Q: Context: Repeat positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) and chest computed tomography (CT) are used to assess the effectiveness of chemoradiotherapy in patients with non-small cell lung cancer (NSCLC); however, the change in the standardized uptake values (SUV) has not been correlated with the pathologic change of the primary tumor.', 'This is a retrospective cohort study of a prospective database of 56 patients who had NSCLC, FDG-PET, and chest CT scans both before and after neoadjuvant therapy, followed by complete resection of their cancer. Maximum SUVs (maxSUV) and tumor size were measured, and the percentage of change was compared with the percentage of nonviable tumor cells. The primary objective was to measure the degree of correlation between these values.', "The change in the maxSUV has a near linear relationship to the percent of nonviable tumor cells in the resected tumors. FDG-PET's maxSUV is better correlated to pathology than the change in size on CT scan (r2 = 0.75, r2 = 0.03, p < 0.001). When the maxSUV decreased by 80% or more, a complete pathologic response could be predicted with a sensitivity of 90%, specificity of 100%, and accuracy of 96%.
Answer: The change in maxSUV on FDG-PET scan after neoadjuvant therapy holds a near linear relationship with pathologic response. It is a more accurate predictor than the change of size on CT scan. When the maxSUV decreases by 80% or more it is likely that the patient is a complete responder irrespective of cell type, neoadjuvant treatment, or the final absolute maxSUV. These findings may help guide treatment strategies.

A:
Is repeat FDG-PET after neoadjuvant therapy a predictor of pathologic response in patients with non-small cell lung cancer?
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