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.

Example Input: To study the long-term effects of selegiline in monotherapy and in combination with levodopa in the early phase of Parkinson disease (PD).', "One hundred fifty-seven de novo PD patients were randomized in a double-blind, placebo-controlled study of 7 years' duration. In the monotherapy part, selegiline significantly delayed the initiation of levodopa therapy vs placebo. The authors now report the results from the combination part of the study, in which 140 patients received selegiline or placebo in addition to individually tailored levodopa therapy.", 'Compared with placebo, selegiline slowed the progression of disease disability as measured by the Unified Parkinson Disease Rating Scale (UPDRS) total score (p = 0.003) or by motor (p = 0.002) and Activities of Daily Living (p = 0.0002) subscores. After 5 years in combination therapy, the mean difference in the UPDRS total score was nearly 10 points, with patients receiving placebo having 35% higher scores. Simultaneously, patients receiving placebo needed progressively higher doses of levodopa than patients receiving selegiline; after 5 years, the mean dosage of levodopa was 19% higher with placebo than with selegiline (p = 0.0002). Considering the entire (monotherapy and combination therapy) 7-year study time, there was a trend for selegiline to delay the start of wearing-off fluctuations (hazard ratio 0.55, p = 0.08). In both phases of the study, selegiline was safe and well tolerated.
Example Output: Does selegiline slow the progression of the symptoms of Parkinson disease?

Example Input: The cutaneous microcirculation vasodilates during acute 6 degrees head-down tilt (HDT, simulated microgravity) relative to upright conditions, more in the lower body than in the upper body.', 'We expected that relative magnitudes of and differences between upper and lower body cutaneous blood flow elevation would be sustained during initial acclimation to simulated microgravity.', 'We measured cutaneous microvascular blood flow with laser-Doppler flowmetry at the leg (over the distal tibia) and cheek (over the zygomatic arch) of eight healthy men before, during, and after 24 h of HDT. Results were calculated as a percentage of baseline value (100% measured during pre-tilt upright sitting).', 'Cutaneous blood flow in the cheek increased significantly to 165 +/- 37% (mean +/- SE, p < 0.05) at 9-12 h HDT, then returned to near baseline values by 24 h HDT (114 +/- 29%, NSD), despite increased local arterial pressure. Microvascular flow in the leg remained significantly elevated above baseline throughout 24 h HDT (427 +/- 85% at 3 h HDT and 215 +/- 142% at 24 h HDT, p < 0.05). During the 6-h upright sitting recovery period, cheek and leg blood flow levels returned to near pre-tilt baseline values.
Example Output: Does simulated microgravity increase cutaneous blood flow in the head and leg of humans?

Example Input: Infection of human immunodeficiency virus (HIV) has been associated with several chronic diseases, including pulmonary artery hypertension and atherosclerosis. However, the underlying mechanisms of these vascular complications are largely unknown. The objective of this study was to test a novel hypothesis that HIV Nef, an accessory HIV protein, may directly affect endothelial functions and gene expression in pulmonary arteries.', 'Fresh porcine pulmonary artery rings and human pulmonary artery endothelial cells (HPAECs) were treated with HIV Nef for 24 h. With a myograph device, vasomotor function was determined with thromboxane A2 analog, U46619, for contraction, bradykinin, and sodium nitroprusside for relaxation. The expression of endothelial nitric oxide synthase (eNOS) was determined with real-time PCR and immunohistochemistry. Nitric oxide (NO) production was determined by Calorimetric Nitric Oxide Assay kit. Superoxide anion levels were detected with lucigenin-enhanced chemiluminescence assay and dihydroethidium (DHE) staining.', 'The endothelium-dependent vasorelaxation in response to bradykinin was significantly reduced in HIV Nef-treated porcine pulmonary artery rings in a concentration-dependent manner. In response to bradykinin (10(-8) mol/L), HIV Nef (10 ng/mL) significantly reduced vasorelaxation by 32% compared with untreated controls (P < 0.05). In addition, HIV Nef significantly decreased eNOS expression in the vessels and HPAECs. HIV Nef at 10 ng/mL significantly decreased NO production in HPAECs by 21% compared with controls (P < 0.05). Furthermore, HIV Nef significantly increased superoxide anion production in porcine pulmonary arteries and HPAECs compared with controls (P < 0.05). Consequently, Mn (III) tetrakis porphyrin, a superoxide dismutase mimic, effectively blocked HIV Nef-induced vasomotor dysfunction and superoxide anion production. The specificity of HIV Nef action was confirmed by anti-Nef antibody blocking and Nef heat inactivation.
Example Output:
Does hIV Nef protein cause endothelial dysfunction in porcine pulmonary arteries and human pulmonary artery endothelial cells?