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.

Q: Our objective was to study the direct effects of meconium on isolated umbilical artery and vein in vitro.', "Intact umbilical artery and vein rings were suspended in 5 ml organ baths containing kreb's solution (pH 7.2, 37 degrees C; bubbled with 2.5% oxygen and 8.07% carbon dioxide, balance nitrogen) for isometric tension recording. Meconium alone (final bath concentration 1%), centrifuged and filtered meconium, and meconium with the lipid fraction removed (separated into < 30,000 kd and > 30,000 kd) were added to the baths. Some vessels were also incubated in 1% meconium for 30 minutes, after which the meconium was washed out. Concentration-response curves to U46619 were obtained. The negative log of the concentration that evokes 50% of the maximal contraction was determined.", 'Umbilical artery and vein had no sustained response to meconium. Tension that developed by rings exposed to meconium was significantly less than control at all concentrations of U46619. There was some loss of the efficacy of meconium after centrifugation-filtration and washing out. Meconium without the lipid fraction had less inhibitory effect than did native meconium.

A: Does meconium inhibit the contraction of umbilical vessels induced by the thromboxane A2 analog U46619?
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Q: Physiological roles of apelin and its specific receptor APJ signaling were investigated in vascular smooth muscle cells (VSMCs). The present study determined whether apelin activates myosin light chain (MLC), a major regulatory event in initiating smooth muscle contraction.', 'To assess MLC activation, we performed Western blot and immunohistochemical studies using an antibody against the phospho-MLC. In VSMCs, apelin induces the phosphorylation of MLC in a concentration-dependent manner with a peak at 2 minutes. Pretreatment of VSMCs with pertussis toxin abolishes the apelin-induced phosphorylation of MLC. Inhibition of protein kinase C (PKC) with GF-109203X markedly attenuated the apelin-induced MLC phosphorylation. In addition, methylisobutyl amiloride, a specific inhibitor of the Na+/H+ exchanger (NHE), and KB-R7943, a potent inhibitor for the reverse mode of the Na+/Ca2+ exchanger (NCX), significantly suppressed the action of apelin. In wild-type mice, apelin phosphorylates MLC in vascular tissue, whereas it had no response in APJ-deficient mice by Western blot and immunohistochemistry. Apelin-induced phosphorylation of MLC was accompanied with myosin phosphatase target subunit phosphorylation.

A: Does apelin stimulate myosin light chain phosphorylation in vascular smooth muscle cells?
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Q: Different risk factors have been suggested for ischemic stroke in young adults. In a group of these patients despite of extensive diagnostic work-up, the primary cause remains unknown. Coagulation tendency is accounted as a possible cause in these patients. Previous studies on factor V Leiden (FVL) as the main cause of inherited thrombophilia for clarifying the role of FVL in stroke have resulted in controversial findings. The current study investigates the role of this factor in ischemic stroke among Iranians.', 'This case-control study was performed between September 2007 and December 2008 in Isfahan, Iran. The case group comprised of 22 patients of which 15 were males and 7 were females with age range of 50 years, diagnosed as ischemic stroke without classic risk factors and the control group consisted of 54 healthy young adults. After filling consent form, venous blood samples were obtained and sent to the laboratory for genetic examination.', 'No FVL mutation was found in the case group. There was one carrier of the mutation as heterozygous in the control group (relative frequency = 1.85%).

A:
Does factor V Leiden have a role in cryptogenic ischemic stroke among Iranian young adults?
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