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.
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Question: Context: Oxidative stress has been considered to play a primary role in the pathogenesis of stress-induced gastric damage. The aim of this study was to investigate the effects of melatonin, ascorbic acid and β-carotene on stress-induced gastric mucosal damage.', 'Fifty-six male Wistar albino rats were divided into control, stress, stress + standard diet, stress + saline, stress + melatonin, stress + ascorbic acid and stress + β-carotene groups. The rats from stress groups were exposed to starvation, immobilization and cold by immobilizing for 8 h at +4°C following 72-hour food restriction. Following stress application, melatonin, ascorbic acid and β-carotene were administered for 7 days. Specimens of gastric tissue were prepared for microscopic and biochemical examinations.', 'Mean histopathological damage scores and mean tissue malondialdehyde levels were significantly decreased but mean tissue glutathione levels and glutathione peroxidase and superoxide dismutase activities were increased in treatment groups vs. stress groups in general. Mean histopathological damage scores of the stress + Mel group was lower than those of stress + D, stress + S, stress + β-car (p < 0.05) and stress + Asc groups (p < 0.005). Additionally, mean tissue catalase activity of the stress + Mel group was higher than that of stress + S (p < 0.005), stress + D (p < 0.05) and stress + β-car groups (p < 0.05).
Answer: Melatonin is more effective than ascorbic acid and β-carotene in improvement of gastric damage induced by intensive stress. We suggest that as well as the direct antioxidant and free radical scavenging potency of melatonin, its indirect effect via the brain-gut axis might account for its greater beneficial action against stress-induced gastric damage.

Answer: Is melatonin more effective than ascorbic acid and β-carotene in improvement of gastric mucosal damage induced by intensive stress?


Question: Context: We analyzed the involvement of thromboxane (TX) A2/prostaglandin (PG) H2 (TP) receptor in ischemia-induced neovascularization in mice.', 'Unilateral hindlimb ischemia was induced by right femoral artery ligature in male C57BL/6J mice (n=7 per group). Animals were then treated with or without TP receptor antagonist (S18886, 5 or 10 mg/kg per day; ramatroban, 10 mg/kg per day) or aspirin (30 mg/kg per day) in drinking water for 21 days. Hindlimb ischemia raised plasma level of TXB2, the stable metabolite of TXA2, by 4.7-fold. This increase was blocked by aspirin treatment whereas S18886 (5 or 10 mg/kg per day) had no effect. However, neither S 18886 nor aspirin affected postischemic neovascularization. We next assessed the putative involvement of TXA2 signaling in angiotensin II (Ang II) proangiogenic pathway. Ang II (0.3 mg/kg per day) enhanced TXB2 plasma levels by 2.6-fold over that of control (P<0.01). Ang II-induced TXB2 upregulation was reduced by cotreatment with Ang II type I receptor antagonist (candesartan, 20 mg/kg per day). Angiographic score, capillary number, and foot perfusion were improved by 1.7-, 1.7-, and 1.4-fold, respectively, in Ang II-treated mice compared with controls (P<0.05). Ang II proangiogenic effect was associated with a 1.6-fold increase in VEGF-A protein content (P<0.05) and a 1.4-fold increase in the number of Mac-3-positive cells (ie, macrophages) in ischemic areas (P<0.05). Interestingly, treatments with TP receptor antagonists or aspirin hampered the proangiogenic effects of Ang II.
Answer: Endogenous activation of TXA2 receptor by eicosanoids did not modulate spontaneous neovascularization in the setting of ischemia. Conversely, TXA2 signaling is involved in Ang II-induced AT1-dependent vessel growth.

Answer: Does thromboxane A2/prostaglandin H2 receptor activation mediate angiotensin II-induced postischemic neovascularization?


Question: Context: It has been proposed that hepatitis B virus (HBV) sub-genotype A1 infections have mild outcomes and a low risk of drug-resistance among patients infected with human immunodeficiency virus (HIV) receiving lamivudine-containing antiretroviral therapy (ART) without tenofovir in Africa.', 'The virologic expression of HBV sub-genotype A1 coinfection was studied over 12 months in HIV-positive adults starting stavudine/lamivudine/nevirapine in Malawi, using Sanger, deep, clonal, and single full-genome sequencing for the sensitive characterization of HBV resistance-associated mutations (RAMs).', 'Among 1117 subjects, 133 (12%) tested HBsAg-positive. After starting ART, retention rates were 96/133 (72%) at 6 months and 54/133 (41%) at 12 months. Based upon the last available follow-up, 92/96 (96%) subjects achieved HIV-1 RNA <40 copies/mL, 48/96 (50%) showed HBV DNA <14 IU/mL, and 24/96 (25%) acquired HBV RAMs. At 6 months, M204I was detected in 8/46 (17%) and 16/17 (94%) subjects using Sanger and deep sequencing, respectively. At 12 months, all viremic patients had multiple resistance and compensatory mutations coexisting on the same HBV genomes. Comparing HBeA-positive (67/133, 50%) with HBeAg-negative subjects, 64/67 (96%) vs 35/66 (55%) showed baseline HBV DNA >2000 IU/mL (P = .0006), 39/47 (17%) vs 9/49 (82%) had persistent HBV DNA detection during follow-up (P < .0001), and 23/47 (49%) vs 2/49 (4%) acquired HBV RAMs (P < .0001). Baseline HBV DNA levels were median 8.1 vs 5.3 log10 IU/mL in subjects with vs those without treatment-emergent RAMs (P < .0001).
Answer: HBV sub-genotype A1 infections showed a severe virologic expression in HIV-positive Malawians. The findings strengthen the urgency of interventions to improve ascertainment and management of chronic hepatitis B in the region.

Answer:
Is hepatitis B virus sub-genotype A1 infection characterized by high replication levels and rapid emergence of drug resistance in HIV-positive adults receiving first-line antiretroviral therapy in Malawi?