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.

Example Input: Context: Histologic evidence of the comparative neurotoxicity of lidocaine, mepivacaine, and prilocaine is incomplete. We compared the intrathecal neurotoxicity in rats among these 3 drugs based on morphologic and neurofunctional findings.', 'Rats (n=169) randomly received 0.12 microL/g of 0%, 2%, 5%, 7.5%, 10%, or 20% lidocaine, mepivacaine, or prilocaine or 25% glucose dissolved in distilled water via a chronically implanted intrathecal catheter. The effect of the agents on neurofunction was evaluated by movement of the hind limb (behavior test) and by sensory threshold (paw-stimulation test). The L1 spinal cord, the posterior and anterior roots, and the cauda equina were removed en bloc 5 days later and examined by light and electron microscopy.', 'A significant decrease in sensory threshold or irreversible hind-limb limitation was observed only in rats receiving 20% lidocaine. Morphologic abnormalities characterized by axonal degeneration were observed in rats receiving > or =7.5% lidocaine, 20% mepivacaine, and 20% prilocaine, at the posterior white matter and the proximal portion of the posterior root just at the entrance into the spinal cord. The incidence of lesions was significantly higher in rats receiving lidocaine than mepivacaine and prilocaine.
Answer: It is suggested that intrathecal mepivacaine and prilocaine are less neurotoxic than highly concentrated lidocaine in a rat intrathecal model.
Example Output: Are intrathecal mepivacaine and prilocaine less neurotoxic than lidocaine in a rat intrathecal model?

Example Input: Context: The fruits of Vitex rotundifolia L. are widely used to treat inflammation of the airway in Traditional Chinese medicine. Previous studies found that casticin, isolated from Vitex rotundifolia, could induce apoptosis of tumor cells. In this study, we evaluated the anti-inflammatory effects of casticin and its underlying molecular mechanism in lipopolysaccharide (LPS)-stimulated macrophages.', 'RAW264.7 cells were pretreated with various concentrations of casticin (0.3-10μM), and then treated with LPS to induce inflammation. We assayed the levels of proinflammatory cytokines and prostaglandin E2 (PGE2) using ELISA, and examined the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and heme oxygenase (HO)-1 by Western blot. We also investigated the anti-inflammatory molecular mechanism by analyzing inflammatory-associated signaling pathways, including the nuclear transcription factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways.', 'We found casticin inhibited the levels of nitric oxide and PGE2, and decreased the production of proinflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor α (TNF-α). In addition, iNOS and COX-2 expression levels were suppressed and casticin increased HO-1 and Nrf2 production in a concentration-dependent manner. Furthermore, casticin significantly inhibited NF-κB subunit p65 proteins in the nucleus and decreased Akt and MAPK activation.
Answer: These results suggest that the anti-inflammatory effect of casticin is due to inhibition of proinflammatory cytokines and mediators by blocking the NF-κB, Akt, and MAPK signaling pathways.
Example Output: Does casticin inhibit COX-2 and iNOS expression via suppression of NF-κB and MAPK signaling in lipopolysaccharide-stimulated mouse macrophages?

Example Input: Context: Elevated homocysteine levels during embryonic development can result in neural tube and cardiovascular defects. The mechanisms that underlie the toxic effect of homocysteine are largely unknown.', 'We cultured mouse neural tube explants to study the effects of homocysteine on the migratory behavior of neural crest cells and on the levels of the gap junction protein Connexin43 (Cx43) and the actin- and Cx43-interacting protein ZO-1.', 'Homocysteine exposure resulted in a significantly augmented maximal migration distance (MMD). The level of Cx43 immunolabeling was 2 times higher in the cytoplasm and cell protrusions of neural crest cells in homocysteine-treated cultures than in control cultures. Furthermore, colocalization of Cx43 and ZO-1 was increased in neural crest cell protrusions by this treatment.
Answer: Increased Cx43 levels were previously shown to result in abnormal embryonic development. Our data raises the hypothesis that the embryotoxic effects of homocysteine may be mediated in part by its effects on Cx43 expression level and gap junction function in neural crest cells.
Example Output:
Are connexin43 levels increased in mouse neural crest cells exposed to homocysteine?