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.

[EX Q]: Context: In atherogenesis, dendritic cells, beside presenting antigens, may be sources of tumour necrosis factor (TNF)alpha and nitric oxide (NO), together with mast cells and smooth muscle cells.', 'We have looked at the expression of TNFalpha and inducible NO synthase (iNOs) by these cells by affinity cytochemistry in autoptical specimens from normal carotid arteries and not ruptured, hemorrhagic or calcified atheromata.', 'Round to dendritic, major histocompatibility complex class II molecules (MHC-II+) cells and avidin-labeled mast cells were rare in normal arteries and significantly more numerous in atheromata. Many MHC-II+ cells expressed S-100 antigen; while a few were positive for phalloidin; appreciable fractions of these cells were immunoreactive for TNFalpha and iNOs, both in control specimens and atheromata. The fraction of mast cells labeled for iNOs was significantly lower in atheromata than in controls. Phalloidin positive cells were the most abundant cell type in the normal intima and atheromata; the fractions of these cells labeled for TNFalpha and iNOs were significantly higher in atheromata than in controls. Very few of these cells were also labeled for MHC-II. Computerized image analysis confirmed that the amounts of iNOs and TNFalpha were higher in atheromata than in controls. The increase in TNFalpha in atheromata was also confirmed by western blot.
Answer: Dendritic cells and mast cells can participate to the generation of TNFalpha and NO in the normal arterial wall and in atheromata, but myointimal cells are candidates as major sources of these molecules.
[EX A]: Are smooth muscle cells , dendritic cells and mast cells sources of TNFalpha and nitric oxide in human carotid artery atherosclerosis?

[EX Q]: Context: A prospective radiographic analysis of deformity correction during the balloon kyphoplasty procedure.', 'To determine the spontaneous reduction of the deformity in prone position, the subsequent deformity correction by the inflatable bone tamp, and the overall deformity correction after deposition of the cement.', 'Fracture mobility has been shown to contribute to fracture reduction in vertebroplasty. Spontaneous reduction has not been taken into account in recently published series of balloon kyphoplasty, but it must be considered when performing vertebral augmentation and when reporting and interpreting the significance of vertebral height restoration.', 'A consecutive series of 39 osteoporotic vertebral compression fractures were treated in 30 patients. Lateral radiographs were taken and analyzed at six different time points: 1) Preoperative standing. During the kyphoplasty procedure, four consecutive radiographs were obtained: 2) after placing the patient in prone position on the operation table, 3) after inflation of the bone tamp (IBT), 4) after deflation and removal of the IBT, and 5) after deposition of the cement. 6) Standing lateral radiographs were taken after the procedure. All fractures were analyzed for improvement in sagittal alignment (Cobb angle, kyphotic angle, sagittal index, vertebral height), complications, and reduction of pain (VAS).', 'Placement of the patient in prone position displayed a significant spontaneous reduction in deformity of 6.5 degrees +/- 4.1 degrees Cobb angle. Inflation of the IBT demonstrated a further reduction of the fracture and a significant improvement of the Cobb angle of 3.4 degrees compared with baseline prone. After deflation and removal of the IBT and placement of the cement, no significant loss of fracture reduction was seen. Postoperative measurement of the Cobb angle by means of standing radiographs demonstrated a 3.1 degrees significant loss of reduction compared with the intraoperative measurement in prone position after cement application. Cement leaks occurred in 9 of 39 vertebral fractures. All patients subjectively reported immediate relief of their typical fracture pain. The VAS score significantly improved from 8.7 +/- 1.4 before surgery to 2.3 +/- 0.9.
Answer: The restoration of height in kyphoplasty is attributed to dynamic fracture mobility as well as to the expansion of the inserted balloon tamp.
[EX A]: Is balloon kyphoplasty effective in deformity correction of osteoporotic vertebral compression fractures?

[EX Q]: Context: Mental fatigue can negatively impact on submaximal endurance exercise and has been attributed to changes in perceived exertion rather than changes in physiological variables. The impact of mental fatigue on maximal anaerobic performance is, however, unclear. Therefore, the aim of the present study was to induce a state of mental fatigue to examine the effects on performance, physiological and perceptual variables from subsequent tests of power, strength and anaerobic capacity.', 'Twelve participants took part in the single-blind, randomised, crossover design study. Mental fatigue was induced by 90 min of the computer-based Continuous Performance Task AX version. Control treatment consisted of 90 min of watching emotionally neutral documentaries. Participants consequently completed countermovement jump, isometric leg extension and a 3-min all-out cycling tests.', 'Results of repeated measures analysis of variance and paired t tests revealed no difference in any performance or physiological variable. Rating of perceived exertion tended to be greater when mentally fatigued (mental fatigue = 19 ± 1 vs control = 18 ± 1, p = 0.096, [Formula: see text] = .232) and intrinsic motivation reduced (mental fatigue = 11 ± 4 vs control = 13 ± 6, p = 0.063, d = 0.597) in the mental fatigue condition.
Answer: Near identical responses in performance and physiological parameters between mental fatigue and control conditions suggest that peripheral mechanisms primarily regulate maximal anaerobic exercise. Whereas mental fatigue can negatively impact submaximal endurance exercise, it appears that explosive power, voluntary maximal strength and anaerobic work capacity are unaffected.
[EX A]:
Does mental fatigue affect maximal anaerobic exercise performance?