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.

[Q]: Accumulated evidence suggests that oxidative stress is involved in amyloid beta (Abeta)-induced cognitive dysfunction. Silibinin (silybin), a flavonoid derived from the herb milk thistle (Silybum marianum), has been shown to have antioxidative properties; however, it remains unclear whether silibinin improves Abeta-induced neurotoxicity. In the present study, we examined the effect of silibinin on the memory impairment and accumulation of oxidative stress induced by Abeta(25-35) in mice.', 'Aggregated Abeta(25-35) (3 nmol) was intracerebroventricularly administered to mice. Treatment with silibinin (2, 20 and 200 mg.kg(-1), once a day, p.o.) was started immediately after the injection of Abeta(25-35). Locomotor activity was evaluated 6 days after the Abeta(25-35) treatment, and cognitive function was evaluated in a Y-maze and novel object recognition tests 6-11 days after the Abeta(25-35) treatment. The levels of lipid peroxidation (malondialdehyde) and antioxidant (glutathione) in the hippocampus were measured 7 days after the Abeta(25-35) injection.', 'Silibinin prevented the memory impairment induced by Abeta(25-35) in the Y-maze and novel object recognition tests. Repeated treatment with silibinin attenuated the Abeta(25-35)-induced accumulation of malondialdehyde and depletion of glutathione in the hippocampus.
[A]: Does silibinin prevent amyloid beta peptide-induced memory impairment and oxidative stress in mice?


[Q]: Mitochondrial permeability transition pore (mPTP) opening is a terminal event leading to mitochondrial dysfunction and cell death under conditions of oxidative stress (OS). However, mPTP blockade with cyclosporine A (CsA) has shown variable efficacy in limiting post-ischemic dysfunction and arrhythmias. We hypothesized that strong feedback between energy dissipating (mPTP) and cardioprotective (mKATP) channels determine vulnerability to OS.', 'Guinea pig hearts (N = 61) were challenged with H2O2 (200 μM) to elicit mitochondrial membrane potential (ΔΨm) depolarization. High-resolution optical mapping was used to measure ΔΨm or action potentials (AP) across the intact heart. Hearts were treated with CsA (0.1 μM) under conditions that altered the activity of mKATP channels either directly or indirectly via its regulation by protein kinase C. mPTP blockade with CsA markedly blunted (P < 0.01) OS-induced ΔΨm depolarization and delayed loss of LV pressure (LVP), but did not affect arrhythmia propensity. Surprisingly, prevention of mKATP activation with the chemical phosphatase BDM reversed the protective effect of CsA, paradoxically exacerbating OS-induced ΔΨm depolarization and accelerating arrhythmia onset in CsA treated compared to untreated hearts (P < 0.05). To elucidate the putative molecular mechanisms, mPTP inhibition by CsA was tested during conditions of selective PKC inhibition or direct mKATP channel activation or blockade. Similar to BDM, the specific PKC inhibitor, CHE (10 μM) did not alter OS-induced ΔΨm depolarization directly. However, it completely abrogated CsA-mediated protection against OS. Direct pharmacological blockade of mKATP, a mitochondrial target of PKC signaling, equally abolished the protective effect of CsA on ΔΨm depolarization, whereas channel activation with 30 μM Diazoxide protected against ΔΨm depolarization (P < 0.0001). Conditions that prevented mKATP activation either directly or indirectly via PKC inhibition led to accelerated ΔΨm depolarization and early onset of VF in response to OS. Investigation of the electrophysiological substrate revealed accelerated APD shortening in response to OS in arrhythmia-prone hearts.
[A]: Do functional crosstalk between the mitochondrial PTP and KATP channels determine arrhythmic vulnerability to oxidative stress?


[Q]: Early inflammatory arthritis is clinically heterogenous and biologically-based indicators are needed to distinguish severe from self-limited disease. Anti-cyclical citrullinated peptides (CCP) have been identified as potential prognostic markers in early arthritis cohorts. Since cytokine networks are known to play a critical role in the pathogenesis of rheumatoid arthritis (RA) and other forms of inflammatory arthritis, a panel of pro- and antiinflammatory cytokines was measured to identify biologically-based subsets of early arthritis, relating cytokine profiles to clinical measures and to the presence of RA-associated autoantibodies.', 'Plasma concentrations of cytokines [interleukin 1beta (IL-1beta), IL-2, IL-4, IL-5, IL-6, IL-7, CXCL8 (IL-8), IL-10, IL-12p70, IL-13, IL-17, granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), interferon-g (IFN-g), CCL2 (monocyte chemoattractant protein-1, MCP-1), CCL4 (MIP-1beta), and tumor necrosis factor-a (TNF-a)] were measured in patients with early, untreated inflammatory arthritis [symptom duration < or = 12 months; > or = 1 swollen joint; RA, n = 41; undifferentiated arthritis (UA), n = 23]. Cytokine expression patterns were determined using cluster analysis.', 'Both pro- and antiinflammatory cytokines were elevated in patients over controls (n = 21). RA clustered into subgroups based solely on cytokine profiles. The "mild" RA subgroup (n = 23) had higher CCL4 (MIP-1beta), CXCL8 (IL-8), IL-2, IL-12, IL-17, IL-5, and IL-10 levels, lower IL-6, IFN-g, GM-CSF, and IL-4 levels, less CCP positivity (52% vs 82%; p < 0.05), and lower CCP titers [71 (78) vs 153 (94); p < 0.01], but similar erythrocyte sedimentation rate, C-reactive protein, and joint counts compared to the "severe" RA groups. CCL4 (MIP-1beta), IL-13, IL-12, TNF-a, and IL-4 best distinguished the groups. Combining UA with RA samples preserved cytokine subgroups and strengthened the autoantibody associations. Fewer UA patients in the "mild" cluster (n = 16) were RF-positive (24% vs 100%; p < 0.002) or CCP-positive (24% vs 66%; p < 0.08) compared to the "severe" group.
[A]:
Is a distinct multicytokine profile associated with anti-cyclical citrullinated peptide antibodies in patients with early untreated inflammatory arthritis?