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: DNA methylation at CpG dinucleotides is modified in tumorigenesis with potential impact on transcriptional activity.', 'We used the Illumina 450 K platform to evaluate DNA methylation patterns of 50 metastatic melanoma tumors, with matched gene expression data.', 'We identified three different methylation groups and validated the groups in independent data from The Cancer Genome Atlas. One group displayed hypermethylation of a developmental promoter set, genome-wide demethylation, increased proliferation and activity of the SWI/SNF complex. A second group had a methylation pattern resembling stromal and leukocyte cells, over-expressed an immune signature and had improved survival rates in metastatic tumors (p < 0.05). A third group had intermediate methylation levels and expressed both proliferative and immune signatures. The methylation groups corresponded to some degree with previously identified gene expression phenotypes.\Question: Are dNA methylation subgroups in melanoma associated with proliferative and immunological processes?
[EX A]: Melanoma consists of divergent methylation groups that are distinguished by promoter methylation, proliferation and content of immunological cells.

[EX Q]: Context: Dynamic pelvic magnetic resonance imaging (DP-MRI) offers a comprehensive evaluation of pelvic organ structure in addition to functional information regarding evacuation. Opportunity to apply this technology can be limited due to regional lack of availability. Ideally, clues from standard anorectal testing could predict abnormalities on DP-MRI, leading to its efficient use. The aim of this study is to determine whether high-resolution anorectal manometry (HR-ARM) correlates with findings on DP-MRI.', "This is a retrospective study of HR-ARM performed on patients with constipation who also underwent DP-MRI. Studies were reviewed for significant findings including posterior pelvic organ prolapse, rectocele>3cm, rectal intussusception, and anorectal angle. Statistical analysis was performed using Pearson's correlation coefficient, Student's t-test, and Fisher's exact test.", 'Twenty-three patients undergoing HR-ARM (age range 25-78) also underwent DP-MRI. All were female; 76% were Caucasian. Twenty had significant structural findings: small pelvic prolapse (n=2), moderate pelvic prolapse (n=10), large pelvic prolapse (n=9), rectocele (n=8), or rectal intussusception (n=3). Only intrarectal pressure on HR-ARM weakly correlated with size of rectocele (r=0.46; P=0.03) and degree of pelvic organ prolapse (r=0.48; P=0.02). The remainder of the HR-ARM parameters did not significantly correlate with DP-MRI findings. Patients with dyssynergy were not more likely to have rectoceles>3cm (44.4% versus 35.7%; P=0.5) or large prolapses (44.4% versus 50%, P=1.0), compared with those without dyssynergy, on HR-ARM.\Question: Are high-resolution anorectal manometry and dynamic pelvic magnetic resonance imaging complementary technologies?
[EX A]: We were unable to find a correlation between HR-ARM findings and structural pelvic defects on DP-MRI. Therefore, these two technologies provide complementary information in the evaluation of defecatory dysfunction.

[EX Q]: Context: We evaluated the associations between dual energy X-ray absorptiometry (DXA) and histologically determined cancellous and cortical bone volume by controlling for vascular calcifications and demographic variables in hemodialysis (HD) patients. Femoral bone mineral density (f-BMD) was associated with cortical porosity.', 'Assessment of bone mass in chronic kidney disease patients is of clinical importance because of the association between low bone volume, fractures, and vascular calcifications. DXA is used for noninvasive assessment of bone mass whereby vertebral results reflect mainly cancellous bone and femoral results reflect mainly cortical bone. Bone histology allows direct measurements of cancellous and cortical bone volume. The present study evaluates the association between DXA and histologically determined cancellous and cortical bone volumes in HD patients.', 'In 38 HD patients, DXA was performed for assessment of bone mass, anterior iliac crest bone biopsies for bone volume, and multislice computed tomography for vascular calcifications.', 'While lumbar bone mineral density (l-BMD) by DXA was not associated with histologically measured cancellous bone volume, coronary Agatson score showed a borderline statistically significant association (P = 0.055). When controlled for age and dialysis duration, f-BMD by DXA was associated with cortical porosity determined by histology (P = 0.005).\Question: Does femoral bone mineral density reflect histologically determined cortical bone volume in hemodialysis patients?
[EX A]:
The usefulness of l-BMD for predicting bone volume is limited most probably because of interference by soft tissue calcifications. In contrast, f-BMD shows significant association with cortical porosity.