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]: 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.
[EX A]: Does meconium inhibit the contraction of umbilical vessels induced by the thromboxane A2 analog U46619?

[EX Q]: Fructus mume (F. mume) has been used as a traditional treatment for ulcer, cough, and digestive problems for many years in Asian countries. Previous studies have demonstrated that F. mume extracts alleviate cognitive deficits in rats with chronic cerebral hypoperfusion and in mice with scopolamine treatments. The present experiment was conducted to examine the effects of F. mume on cognitive impairments in 5XFAD transgenic mice with five familial Alzheimer's disease (AD) mutations.", 'F. mume was administered daily to 5XFAD mice at 12 weeks of age and continued for 90 days. Cognitive function was evaluated using a spatial memory version of the Morris water maze task, the object/location novelty recognition test, and contextual fear conditioning at 24 weeks of age. To elucidate the possible mechanisms underlying the memory improving effects of F. mume in 5XFAD mice, we examined alterations in hippocampal cholinergic function.', 'Vehicle-treated 5XFAD mice exhibited hippocampus-dependent memory impairments compared with non-transgenic littermates, which was reversed in F. mume-treated 5XFAD mice. In addition, reduced hippocampal choline acetyltransferase (ChAT) levels in 5XFAD mice were reversed by F. mume treatment, indicating that F. mume enhances the effects of cholinergic neuronal function.
[EX A]: Do fructus mume extracts alleviate cognitive impairments in 5XFAD transgenic mice?

[EX Q]: Our previous studies show that 2-adrenergic receptor (2-AR) is highly expressed in most Her2-overexpressing breast cancers. However, the mechanisms underlying upregulation of the 2-AR expression in Her2-overexpressing breast cancer cells are not fully understood. The clinical significance of the 2-AR overexpression in breast cancer is unclear.', 'Human breast cancer cells MCF-7 and MCF-7/Her2 were transfected with the let-7 mimics or inhibitors. The expression of 2-AR was analyzed by Western blot. The 2-AR status in primary and metastatic sites of breast cancer and the human breast cancer tissue microarrays containing 49 primary tumors and 50 metastatic lymph node tissues was analyzed by immunohistochemistry. The correlation of lymph node metastasis with the 2-AR level was determined in 59 primary tumor tissues from the patients with Her2-positive breast cancer. The clinical prognostic significance of the 2-AR overexpression in the patients with Her2-positive breast cancers was evaluated by a retrospective study.', 'The let-7f level in Her2-overexpressing breast cancer cells SKBR3 and BT474 was significantly lower than that in MCF-7 cells, which express low level of Her2. Ectopic expression of Her2 in MCF-7 cells (MCF-7/Her2) represses the expression of microRNA let-7f, which is previously identified to regulate baseline 2-AR expression. The treatment with MEK1/2 inhibitors PD98059 or PD184352 effectively restored the let-7f level, suggesting that Her2-overexpression-mediated ERK constitutive activation inhibited let-7f, leading to the upregulation of the 2-AR expression. The transfection with the let-7f mimics markedly downregulated the 2-AR level, whereas the let-7 inhibitor significantly upregulated the 2-AR expression in both parental MCF-7 and MCF-7/Her2 cells. In addition, treatment of MCF-7/Her2 cells with isoproterenol resulted in a concentration-dependent reduction of the let-7f expression, demonstrating that the inhibitory effect of Her2 overexpression on let-7f can be reinforced by agonist-triggered 2-AR activation. We further demonstrate that high level of 2-AR associates with lymph node metastasis and poor outcome in the patients with Her2-positive breast cancer.
[EX A]:
Does a Her2-let-7-2-AR circuit affect prognosis in patients with Her2-positive breast cancer?