In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Q: Context: Remote renal ischemia-reperfusion injury (IRI) following infra-renal aortic occlusion leads to acute kidney injury and systemic inflammation. Hydrogen sulfide is a mediator of IRI and can ameliorate tissue injury in many organ systems. Its role in vascular surgery has yet to be established. We assessed the role of hydrogen sulfide in a rodent model of aortic occlusion.', 'Wistar rats were divided into sham, control, and treatment groups (n = 6). Inflammation was assessed using a nonrecovery protocol. The infra-renal aorta was cross-clamped for 60 min and animals were reperfused for 120 min. Ten minutes before clamp release, treatment animals received hydrogen sulfide (10, 30, or 50 μg/kg) and control animals received 0.9% saline injected into the retroperitoneum. Renal injury and histology were assessed by a recovery protocol. The procedure was identical to the nonrecovery arm but with a single dose of hydrogen sulfide (30 μg/kg) and animals were recovered for 7 days.', 'There was no difference in animal weight between the groups (P = 0.337). In the nonrecovery arm, there was a reduction in serum levels of tumor necrosis factor alpha in sulfide-treated animals compared with controls (909 ± 98 vs. 607 ± 159 pg/mL; P = 0.0038). There was also a reduction in myeloperoxidase-positive cells in renal tissue in the sulfide-treated animals compared with controls (8 ± 4 vs. 17 ± 9; P = 0.03). There was no difference in histological injury score or endothelin-1 levels. In the recovery arm, there was no difference in renal function, Kidney Injury Molecule-1 levels, or histological injury scores.\Question: Does hydrogen sulfide reduce inflammation following abdominal aortic occlusion in rats?

A: Hydrogen sulfide has systemic and renal anti-inflammatory effects in remote IRI following aortic occlusion in rats.
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Q: Context: HIV-1-infected and/or immune-activated microglia and macrophages are pivotal in the pathogenesis of HIV-1-associated neurocognitive disorders (HAND). Glutaminase, a metabolic enzyme that facilitates glutamate generation, is upregulated and may play a pathogenic role in HAND. Our previous studies have demonstrated that glutaminase is released to the extracellular fluid during HIV-1 infection and neuroinflammation. However, key molecular mechanisms that regulate glutaminase release remain unknown. Recent advances in understanding intercellular trafficking have identified microvesicles (MVs) as a novel means of shedding cellular contents. We posit that during HIV-1 infection and immune activation, microvesicles may mediate glutaminase release, generating excessive and neurotoxic levels of glutamate.', 'MVs isolated through differential centrifugation from cell-free supernatants of monocyte-derived macrophages (MDM) and BV2 microglia cell lines were first confirmed in electron microscopy and immunoblotting. As expected, we found elevated number of MVs, glutaminase immunoreactivities, as well as glutaminase enzyme activity in the supernatants of HIV-1 infected MDM and lipopolysaccharide (LPS)-activated microglia when compared with controls. The elevated glutaminase was blocked by GW4869, a neutral sphingomyelinase inhibitor known to inhibit MVs release, suggesting a critical role of MVs in mediating glutaminase release. More importantly, MVs from HIV-1-infected MDM and LPS-activated microglia induced significant neuronal injury in rat cortical neuron cultures. The MV neurotoxicity was blocked by a glutaminase inhibitor or GW4869, suggesting that the neurotoxic potential of HIV-1-infected MDM and LPS-activated microglia is dependent on the glutaminase-containing MVs.\Question: Do glutaminase-containing microvesicles from HIV-1-infected macrophages and immune-activated microglia induce neurotoxicity?

A: These findings support MVs as a potential pathway/mechanism of excessive glutamate generation and neurotoxicity in HAND and therefore MVs may serve as a novel therapeutic target.
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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].\Question: Is direct observation a valid criterion for estimating physical activity and sedentary behavior?

A:
This study provides evidence that DO can be used as a criterion measure of absolute intensity in free-living validation studies.
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