Given a passage, 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.

[EX Q]: Pulmonary hypertension (PH) is prognosti- cally important in chronic obstructive pulmonary disease (COPD). Since PH only weakly correlates with hypoxemia, other factors must play a role.', 'To investigate whether polymorphisms of the serotonin transporter (5HTT), serotonin-2a receptor (5HTR2a) and endothelial nitric oxide synthetase (eNOS) are related to PH in COPD.', 'In 59 COPD patients who underwent right heart catheterization, 6-min walking distance, NYHA functional class, pulmonary function tests, blood gases and 5HTT, 5HTR2a and eNOS (4ab and T298C) polymorphisms were determined.', 'Forty-nine COPD patients in NYHA functional class III-IV were included. Ten were excluded due to comorbid causes of PH (mainly chronic thromboembolic). PH (mPAP > or =25 mm Hg) was present in 55% and usually mild, but out of proportion (mPAP > or =40 mm Hg) in 12%. Patients with PH had significantly higher frequencies of the 5HTT-L-allele (52%) compared to individuals without PH (36%), and LL homozygote patients had more severe PH. In patients with out-of-proportion PH, the L-allelic frequency was even 75%. We found no association of 5HTR2a and eNOS polymorphism with PH in COPD.
[EX A]: Are genetic polymorphisms of the serotonin transporter , but not the 2a receptor or nitric oxide synthetase , associated with pulmonary hypertension in chronic obstructive pulmonary disease?

[EX Q]: Dual activation by TSH of the phospholipase C and cAMP cascades has been reported in human thyroid cells. In contrast, Singh et al. reported convincing data in FRTL-5 thyrocytes arguing against such an effect in this model. Their data in FRTL-5 cells indicated no increase in inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] in response to TSH. Therefore, the authors questioned results previously obtained on human cells by cruder methodology.', 'We investigated the formation of inositol phosphates by HPLC techniques in human thyroid slices to separate the inositol phosphate isomers.', 'Ins(1,4,5)P3, inositol 1,3,4-trisphosphate, and inositol 1,3,4,5-tetrakisphosphate were increased after TSH stimulation. The effect of TSH in human thyroid cells was reproduced by recombinant TSH and prevented by antibodies blocking the TSH receptor. Thyroid-stimulating antibodies at concentrations eliciting a cAMP response equivalent to TSH failed to stimulate inositol phosphate generation.
[EX A]: Does thyrotropin stimulate the generation of inositol 1,4,5-trisphosphate in human thyroid cells?

[EX Q]: In chronic renal failure leptin levels are elevated and BMD decreased, however, so far data about correlations between leptin and BMD in dialyzed patients are scarce. It has been suggested that leptin is a predictor of BMD in postmenopausal women. We examined the relationships between leptinemia, BMD and bone metabolism in HD and CAPD patients. We also assessed whether leptin is significant and independent predictor of BMD in dialyzed patients.', 'BMD was measured using dual energy X-ray absorptiometry (DEXA) at lumbar spine and femoral neck in 25 HD and 23 CAPD patients. Markers of bone turnover and leptin were studied using commercially available kits.', 'In femoral neck BMD was significantly higher in CAPD patients, without significant differences in BMD in lumbar spine. There was a negative correlation between BMD at the femoral neck and time on hemodialysis (r= -0.45, p < 0.05). In CAPD patients BMD at the lumbar spine correlated negatively with vitamin D3 (r= -0.54, p < 0.05), osteocalcin (r= 0.54, p < 0 .05), and positively with BMI (r= 0.63, p < 0.01). BMD at the femoral neck correlated positively with BMI (r= 0.59, p < 0.01), and negatively with osteocalcin (r= -0.63, p < 0.05) and time on CAPD (r= -0.52, p < 0.05). Leptin correlate only with cholesterol (r= 0.25, p < 0.05), TSH (r= 0.35, p < 0.01), ss(2) microglobulin (r= 0.32, p < 0.001) and BMD at the femoral neck (r= -0.23, p < 0.05)in all dialyzed (HD and CAPD) patients.
[EX A]:
Are bone mineral density and bone metabolism related to leptin in hemodialyzed and peritoneally dialyzed uremic patients?