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: For high-resolution microscopy, cells have to be analyzed through thin glass coverslips. Therefore, it is necessary to culture cells on coverslips for preservation of cell morphology. We found cell attachment and spreading to be relatively slow processes, even when cells were plated on coated coverslips. This slowness presents a problem, particularly when synchronized cell populations are used.', 'In this paper, we present a method that is based on glow-discharged carbon coating of coverslips which promotes rapid attachment and spreading of cells, enabling rapid analysis of cells after plating. Results obtained with carbon-coated coverslips were compared with those of other types of coating. Two fibroblast lines, an epithelial cell line, and a carcinoma cell line were tested.
Answer: All cell lines showed a rapid adhesion on carbon-coated coverslips. With fibroblasts we found the carbon coating to be superior to other coatings tested, mainly because the carbon did not influence cell morphology. Using synchronized or irradiated cells produced similar results. The superior performance of carbon coating is probably due to carboxylic groups on the glow-discharged carbon layer. The carbon layer does not interfere with microscopy or immunocytochemical staining procedures.

Output: Does coating of coverslips with glow-discharged carbon promote cell attachment and spreading probably due to carboxylic groups?

Input: Consider Input: Context: Chemokines play a critical role in the pathogenesis of asthma and facilitate the recruitment of inflammatory cells in the airways. Evidence now suggests that airway smooth muscle (ASM) may serve as a source of chemokines in inflamed airways. Although vitamin D has potent anti-inflammatory properties in vitro in some cell types, its effects on ASM cells remain unclear. Here, we investigated whether 1alpha, 25-dihydroxy vitamin D3 (calcitriol) modulated chemokine production in ASM.', 'Human ASM cell cultures were derived from tracheal samples taken during surgery. ASM cells were treated with tumour necrosis factor alpha (TNFalpha) and/or interferon gamma (IFNgamma) for 24 h in the presence of calcitriol and/or the glucocorticoid fluticasone added 2 h before. RANTES (regulated upon activation, normal T-cell expressed and secreted), interferon-inducible protein 10 (IP-10) and fractalkine (FKN) levels in cell supernatants were measured by ELISA.', 'In TNFalpha-treated cells, calcitriol inhibited RANTES and IP-10 secretion in a concentration-dependent manner. FKN levels were negligible. In TNFalpha/IFNgamma-treated cells, whereas fluticasone or calcitriol alone partially inhibited RANTES secretion (by 38 and 20%, respectively), the combination of both drugs additively inhibited RANTES secretion (by 60%). No effect was observed on IP-10 secretion. Whereas fluticasone enhanced FKN secretion (by 50%), calcitriol significantly decreased FKN levels (by 50%). Interestingly, calcitriol blocked the stimulatory effect of fluticasone on FKN secretion, which was inhibited by 60% with the combination of calcitriol and fluticasone.
Answer: These findings suggest that vitamin D uniquely modulates human ASM expression of chemokines and may exert some beneficial effects in the treatment of steroid-resistant patients with asthma.
Output: Do vitamin D and glucocorticoids differentially modulate chemokine expression in human airway smooth muscle cells?