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: Parkinsonian signs, especially gait impairment, are common and associated with morbidity and mortality in older persons. Our objective was to test the hypothesis that substantia nigra neurofibrillary tangles (NFTs) are related to parkinsonian signs in older persons with and without dementia.', "We studied 86 deceased older Catholic clergy without idiopathic Parkinson's disease from the Religious Order Study, a longitudinal clinical-pathological study. Mean age at death was 85.3 years. Signs of gait disturbance, bradykinesia, rigidity, and tremor were assessed proximate to death using a modified Unified Parkinson's Disease Rating Scale. Forty-micrometer paraffin-embedded sections of substantia nigra were bleached before tau immunohistochemistry and the optical disector was used to count NFTs. We used multivariable linear regression to examine parkinsonian signs as a function of nigra NFTs, controlling for age, sex, education, and cortical NFTs.", 'Substantia nigra NFTs were present in 67 of 86 persons (77.9%). After controlling for age, sex, education, and cortical NFTs, nigra NFTs were related to gait impairment (p < 0.001), but not bradykinesia, rigidity, or tremor. Results were not confounded by dementia, Braak score, neuroleptic medication, cerebral infarcts, or Lewy bodies.
Answer: NFTs in the substantia nigra are associated with gait impairment in older persons with and without dementia.
Example Output: Are substantia nigra tangles related to gait impairment in older persons?

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: Diabetic retinopathy is a common diabetic eye disease caused by changes in retinal ganglion cells (RGCs). Several studies suggest that the oxidative stress plays a role in the pathogenesis of diabetic retinopathy in adults. Formononetin is a flavone with powerful antioxidant properties that exists naturally in various plants and Chinese medicine. In the present study, an attempt has been made to investigate the antioxidative effects of formononetin on H2O2-induced apoptosis of RGC-5 cells.', 'Exposure of retinal ganglion cells (RGCs) to the indicated concentrations of formononetin and H2O2 for 24 h, analyzed by MTT assay. Cells were stained with Annexin V-FITC and PI, analyzed by flow cytometry. And the level of superoxide anions, malondialdehyde (MDA, a marker of lipid peroxidation), 8-hydroxy-2-deoxyguanosine (8-OHdG, indicator of oxidative DNA damage) and MnSOD (manganese superoxide dismutase) activity were measured by kits.', 'Formononetin reduced hydrogen peroxide (H2O2)-induced apoptosis and improved the levels or activity of indicators of oxidative stress. Formononetin also inhibited the activation of nuclear factor-kappaB (NF-κB), which is a significant transcription factor for RGC-5 apoptosis.
Answer: Formononetin may be developed as a antioxidant drug to treat diabetic retinopathy.
Example Output:
Does formononetin attenuate hydrogen peroxide ( H2O2 ) -induced apoptosis and NF-κB activation in RGC-5 cells?