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.

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.\Question: Are global histone H3 lysine 27 triple methylation levels reduced in vessels with advanced atherosclerotic plaques?
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.

Context: By using the techniques of PCR and restriction fragment length polymorphism (RFLP), we established a classification method for HBV genome based on viral S gene of asymptomatic HBV carriers (AsC).', 'By using this method we classified HBV DNA of AsC living in Guangzhou, Shenyang, Beijing and Chongqing.', 'Among the AsC of Guangzhou, genotype B was 32.8%, genotype C 42.7%, mixed genotypes B and C 23.0%, others 1.6%; among the AsC of Chongqing, genotype B was 35.0%, genotype C 40.0%, mixed genotypes B and C 25.0%; among the AsC of Beijing, genotype B was 25.0%, genotype C 50.0%, mixed genotypes B and C 25.0%; among the AsC of Shenyang, genotype B was 11.1%, genotype C 88.9%. The prevalent HBV strains in China are genotype C and genotype B, and genotype C is the main genotype in west China.\Question: Does [ Establishment of a method for classification of HBV genome and it 's application ]?
The established method for genotyping is simple and convenient. Using this method, we also classified HBV DNA of the patients with chronic hepatitis B and liver cirrhosis living in Guangzhou, and found that mixed genotypes B and C was in 50.0% of the patients detected, suggesting the mixed infection might lead to a severe damage of the liver tissue.

Context: To conduct a systematic review of studies reporting on the development or validation of comorbidity indices using administrative health data and compare their ability to predict outcomes related to comorbidity (ie, construct validity).', 'We conducted a comprehensive literature search of MEDLINE and EMBASE, until September 2012. After title and abstract screen, relevant articles were selected for review by two independent investigators. Predictive validity and model fit were measured using c-statistic for dichotomous outcomes and R(2) for continuous outcomes.', 'Our review includes 76 articles. Two categories of comorbidity indices were identified: those identifying comorbidities based on diagnoses, using International Classification of Disease codes from hospitalization or outpatient data, and based on medications, using pharmacy data. The ability of indices studied to predict morbidity-related outcomes ranged from poor (C statistic ≤ 0.69) to excellent (C statistic >0.80) depending on the specific index, outcome measured, and study population. Diagnosis-based measures, particularly the Elixhauser Index and the Romano adaptation of the Charlson Index, resulted in higher ability to predict mortality outcomes. Medication-based indices, such as the Chronic Disease Score, demonstrated better performance for predicting health care utilization.\Question: Does a systematic review identify valid comorbidity indices derived from administrative health data?

A number of valid comorbidity indices derived from administrative data are available. Selection of an appropriate index should take into account the type of data available, study population, and specific outcome of interest.