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.

[Q]: Context: To explore the effect of delta-opioid receptor (DOR) in electroacupuncture (EA) protecting the brain against acute ischemic injury.', 'Fifty-one rats were randomly divided into sham ischemia group, ischemia group, sham EA group, EA group, and EA+DOR antagonist (naltrindole) group. Transient focal cerebral ischemia (1 hour) was induced in rat brain by middle cerebral artery occlusion (MCAO) method. EA was applied on Shuigou (GV 26) and Neiguan (PC 6) for 30 min, starting immediately after the onset of reperfusion. Neurological deficit scores and volume of cerebral infarction were detected after 24-hour reperfusion. Other 12 rats were randomly divided into sham ischemia group, ischemia group, EA group and EA + naltrindole group. DOR protein expressions were assessed by Western blotting after 24-hour reperfusion.', 'In comparison with the ischemia group and sham EA group, EA significantly reduced ischemic infarction and neurological deficits (P<0.05); EA significantly increased the expression of 60 kD DOR protein (P<0.05) and tended to increase that of 36 kD DOR protein (P>0.05). When naltrindole was combined with EA, the naltrindole completely abolished the EA-induced protection in ischemic infarction and neurological deficits, and also arrested the expression of DOR.
Answer: EA can up-regulate DOR expression and protect the brain from ischemia-reperfusion injury.
[A]: Does [ Electroacupuncture protect the brain against acute ischemic injury via up-regulation of delta-opioid receptor in rats ]?


[Q]: Context: Altered cerebrospinal fluid (CSF) levels of lactate have been described in neurodegenerative diseases and related to mitochondrial dysfunction and neuronal degeneration. We investigated the relationship between CSF lactate levels, disease severity, and biomarkers associated with neuroaxonal damage in patients with multiple sclerosis (MS).', 'One-hundred eighteen subjects with relapsing-remitting multiple sclerosis (RRMS) were included, along with one-hundred fifty seven matched controls. CSF levels of lactate, tau protein, and neurofilament light were detected at the time of diagnosis. Patients were followed-up for a mean of 5 years. Progression index (PI), multiple sclerosis severity scale (MSSS), and Bayesian risk estimate for multiple sclerosis (BREMS) were assessed as clinical measures of disease severity and progression. Differences between groups and correlation between CSF lactate, disease severity and CSF biomarkers of neuronal damage were explored.', 'CSF lactate was higher in RRMS patients compared to controls. A negative correlation was found between lactate levels and disease duration. Patients with higher CSF lactate concentration had significantly higher PI, MSSS, and BREMS scores at long-term follow-up. Furthermore, CSF lactate correlated positively and significantly with CSF levels of both tau protein and neurofilament light protein.
Answer: Measurement of CSF lactate may be helpful, in conjunction with other biomarkers of tissue damage, as an early predictor of disease severity in RRMS patients. A better understanding of the alterations of mitochondrial metabolic pathways associated to RRMS severity may pave the way to new therapeutic targets to contrast axonal damage and disease severity.
[A]: Is cerebrospinal fluid lactate associated with multiple sclerosis disease progression?


[Q]: Context: Physical activity and sedentary behavior measurement tools need to be validated in free-living settings. Direct observation (DO) may be an appropriate criterion for these studies. However, it is not known if trained observers can correctly judge the absolute intensity of free-living activities.', 'To compare DO estimates of total MET-hours and time in activity intensity categories to a criterion measure from indirect calorimetry (IC).', 'Fifteen participants were directly observed on three separate days for two hours each day. During this time participants wore an Oxycon Mobile indirect calorimeter and performed any activity of their choice within the reception area of the wireless metabolic equipment. Participants were provided with a desk for sedentary activities (writing, reading, computer use) and had access to exercise equipment (treadmill, bike).', 'DO accurately and precisely estimated MET-hours [% bias (95% CI) = -12.7% (-16.4, -7.3), ICC = 0.98], time in low intensity activity [% bias (95% CI) = 2.1% (1.1, 3.2), ICC = 1.00] and time in moderate to vigorous intensity activity [% bias (95% CI) -4.9% (-7.4, -2.5), ICC = 1.00].
Answer: This study provides evidence that DO can be used as a criterion measure of absolute intensity in free-living validation studies.
[A]:
Is direct observation a valid criterion for estimating physical activity and sedentary behavior?