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.

Input: Consider Input: Context: Severe mitral regurgitation (MR) reduces left atrial thrombus formation in patients with mitral stenosis (MS) and atrial fibrillation (AF). Plasma D-dimer levels represent a biochemical marker for fibrinolytic activity in prothrombotic states. The prothrombotic burden in patients with mitral valve disease and/or AF was assessed using plasma D-dimer levels.', 'The study population included 89 patients with mitral valve disease, 21 with AF but normal valves, and 15 healthy controls. The mitral valve group was subdivided into patients with MS (n = 27), severe MR (n = 26), and MS with concomitant with severe MR (MS/MR; n = 36). These subgroups were further subdivided according to the atrial rhythm (sinus rhythm (SR)+AF).', 'The mean left atrial size was increased in all groups with cardiac disease. D-dimer levels were highest in the MS+AF subgroup (527 +/- 134 microg/l). Patients with MS+AF, MS+SR, and nonvalvular AF had significantly higher D-dimer levels than controls (p < 0.01, by ANOVA). Patients with MR had normal levels of D-dimer. The atrial rhythm did not influence D-dimer levels in the MS/MR subgroup, or in the pure MR subgroup (p = NS).
Answer: Plasma D-dimer levels correlated with the embolic risk in mitral valve disease and non-valvular AF. The highest levels were found in patients with MS+AF and non-valvular AF. Severe MR decreased the D-dimer levels in MS and/or AF to control levels.

Output: Does mitral regurgitation reduce systemic coagulation activity in patients with rheumatic heart disease?

Input: Consider Input: Context: Mutations of the caspase-activating recruitment domain 15 (CARD15) gene on chromosome 16 are associated with chronic inflammatory granulomatous bowel disease (Crohn's disease). Sarcoidosis is a systemic granulomatous disease with unknown etiology, which shares histological features with Crohn's disease.", 'To evaluate whether ethnic Danes with sarcoidosis have an increased frequency of CARD15 mutations compared to healthy control subjects.', 'Genotyping for CARD15 mutations R702W, G908R, and L1007fsinsC, also designated single nucleotide polymorphism (SNP) SNP8, SNP12 and SNP13, respectively, were performed by capillary electrophoresis single-strand confirmation polymorphism in 53 patients with histologically verified sarcoidosis and in 103 healthy controls.', 'The frequencies of CARD15 mutations in sarcoidosis patients were: SNP8, 4/106 chromosomes (3.8%); SNP12, 2/106 chromosomes (1.9%); SNP13, 2/106 chromosomes (1.9%); SNP8+SNP12+SNP13, 8/106 chromosomes (7.6%). All 8 patients were heterozygous. The frequencies in controls were: SNP8, 9/206 chromosomes (4.4%); SNP12, 2/206 chromosomes (1.0%); SNP13, 4/206 chromosomes (1.9%); SNP8+SNP12+SNP13, 15/206 chromosomes (7.3%). All controls were heterozygous. The differences were not statistically significant (p>0.05). Furthermore, the course of disease was not significantly different in the 8 patients with CARD15 mutations and the 45 patients without mutations.
Answer: The frequency of CARD15 mutations is not increased in ethnic Danish patients with sarcoidosis, and heterozygosity for such mutations apparently has no influence on the course of disease.

Output: Are cARD15 single nucleotide polymorphisms 8 , 12 and 13 increased in ethnic Danes with sarcoidosis?

Input: Consider Input: Context: Single-cell gel electrophoresis, or the comet assay, a technique widely used for DNA damage analysis, has been used recently for detecting DNA fragmentation in cells undergoing apoptosis. However, the number of variants of this assay used thus far primarily detected the late stages of DNA fragmentation. Therefore, monitoring the progression of DNA fragmentation, which could greatly improve the analysis of cell death induction and progression at the single-cell level, has not been possible with this assay.', 'In the present study, a modification of the original neutral comet assay developed by Ostling and Johanson (Biochem Biophys Res Commun 123:291-298, 1984) was used to detect various stages of DNA fragmentation. This assay involves cell lysis with anionic detergents at nearly neutral pH (9.5) and does not include high salt concentration, unlike most other published methods. BMG-1 human glioma cells were induced to undergo programmed cell death by treating with a large dose (100 microM) of etoposide, and comets were prepared after different durations (1-24 h) of treatment.', 'In contrast to results of previously published studies, comets with different shapes reflecting progressive stages of DNA fragmentation were observed. Of these, six distinct shapes were identified and divided into three different categories based on the extent of fragmentation. Type A comets had a large head separated by a narrow "neck" region from an oval bulging tail that indicated initiation of fragmentation. Type B and C comets had a constantly diminishing head associated with a corresponding expansion of the tail and reflected intermediate and late stages of fragmentation, respectively. Type A and B comets appeared at a high frequency during early time points (1-6 h), whereas type C comets that indicated late stages of fragmentation were observed only after extended treatment (24 h). As a result, an elaborate kinetics of the progression of DNA fragmentation could be obtained.
Answer: The present single-cell gel electrophoresis assay offers a significant improvement in monitoring the kinetics of DNA fragmentation induced during programmed cell death. Coupled with its simplicity and the ability to detect responses of small cell subpopulations, this method can be used for a reliable and sensitive analysis of the progression of cell death in different cell types and treatment conditions.
Output: Does single-cell gel electrophoresis assay monitor precise kinetics of DNA fragmentation induced during programmed cell death?