instruction:
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.
question:
Context: Infection of human immunodeficiency virus (HIV) has been associated with several chronic diseases, including pulmonary artery hypertension and atherosclerosis. However, the underlying mechanisms of these vascular complications are largely unknown. The objective of this study was to test a novel hypothesis that HIV Nef, an accessory HIV protein, may directly affect endothelial functions and gene expression in pulmonary arteries.', 'Fresh porcine pulmonary artery rings and human pulmonary artery endothelial cells (HPAECs) were treated with HIV Nef for 24 h. With a myograph device, vasomotor function was determined with thromboxane A2 analog, U46619, for contraction, bradykinin, and sodium nitroprusside for relaxation. The expression of endothelial nitric oxide synthase (eNOS) was determined with real-time PCR and immunohistochemistry. Nitric oxide (NO) production was determined by Calorimetric Nitric Oxide Assay kit. Superoxide anion levels were detected with lucigenin-enhanced chemiluminescence assay and dihydroethidium (DHE) staining.', 'The endothelium-dependent vasorelaxation in response to bradykinin was significantly reduced in HIV Nef-treated porcine pulmonary artery rings in a concentration-dependent manner. In response to bradykinin (10(-8) mol/L), HIV Nef (10 ng/mL) significantly reduced vasorelaxation by 32% compared with untreated controls (P < 0.05). In addition, HIV Nef significantly decreased eNOS expression in the vessels and HPAECs. HIV Nef at 10 ng/mL significantly decreased NO production in HPAECs by 21% compared with controls (P < 0.05). Furthermore, HIV Nef significantly increased superoxide anion production in porcine pulmonary arteries and HPAECs compared with controls (P < 0.05). Consequently, Mn (III) tetrakis porphyrin, a superoxide dismutase mimic, effectively blocked HIV Nef-induced vasomotor dysfunction and superoxide anion production. The specificity of HIV Nef action was confirmed by anti-Nef antibody blocking and Nef heat inactivation.\Question: Does hIV Nef protein cause endothelial dysfunction in porcine pulmonary arteries and human pulmonary artery endothelial cells?
answer:
HIV Nef protein significantly decreases endothelium-dependent vasorelaxation in porcine pulmonary arteries. It also reduces eNOS expression and induces oxidative stress in both porcine pulmonary arteries and HPAECs. This study demonstrates a new mechanism of HIV Nef, which causes endothelial dysfunction and may contribute to the human pulmonary artery disease in HIV-infected patients.


question:
Context: Hyperoxia increases oxidative stress through the generation of reactive oxygen species and may therefore enhance inflammation in the lungs. The aim of this study was to investigate whether short term supplementary oxygen (28%) increases oxidative stress and inflammation in the airways by measuring 8-isoprostane and interleukin 6 (IL-6) concentrations in exhaled breath condensate.', 'Twenty three healthy subjects (12 men, mean (SD) age 48 (7) years) and 23 patients with chronic obstructive pulmonary disease (COPD; 15 men, mean (SD) age 56 (5) years) were studied. 8-isoprostane and IL-6 concentrations were measured by immunoassay.', 'Increased concentrations of 8-isoprostane and IL-6 were found in all subjects after breathing 28% oxygen for 1 hour. In healthy subjects the concentrations of 8-isoprostane and IL-6 were 10.9 (2.9) pg/ml and 4.9 (0.8) pg/ml, respectively, compared with baseline concentrations of 6.1 (1.3) pg/ml and 2.9 (0.6) pg/ml, and in patients with COPD the concentrations were 27.9 (3.1) pg/ml and 8.3 (1.2) pg/ml), respectively, compared with baseline concentrations of 18.9 (3.6) pg/ml and 6.3 (0.6) pg/ml. By contrast, breathing air through the same face mask for 1 hour had no significant effects on 8-isoprostane or IL-6 concentrations in normal subjects or those with COPD.\Question: Does supplementary oxygen in healthy subjects and those with COPD increase oxidative stress and airway inflammation?
answer:
These findings suggest that short term supplementary oxygen may enhance oxidative stress and inflammation in the airways. Whether this happens with long term oxygen therapy needs to be determined.


question:
Context: This study examines the influence of surgical management (elimination of the infectious focus and abdominal lavage) on survival and the inflammatory response in the various compartments of the body: local (abdomen), systemic (blood) and distant organ (lungs).', 'Peritonitis was established in mice by cecal ligation and puncture (CLP). After 24 h, a group was made in which the infected cecum was resected and the abdominal cavity was lavaged (RES), and another group that received no surgical resection (NoRES). Survival was examined over a period of 96 h. Mice were sacrificed at 24 (sham and CLP), 48 and 72 h after CLP to measure inflammatory parameters.', 'Survival was significantly lower is NoRES compared to sham and RES (p = 0.006, p = 0.014, respectively). Intraperitoneal parameters were improved in the RES group compared to sham but results were not significantly different between groups. In plasma, levels of interleukin-6 (IL-6) were decreased in RES (p = 0.048). Accordingly, anti-inflammatory IL-10 in plasma was increased in this group (p = 0.031). In the lung, keratinocyte-derived chemokine (KC) and myeloperoxidase (MPO) was reduced indicating decreased granulocytes accumulation in the lung in the RES group (p = 0.012 and p = 0.004, respectively).\Question: Does surgical therapy attenuate abdominal and extra-abdominal inflammation in experimental peritonitis?
answer:

In experimental secondary peritonitis surgical management improves survival and attenuates the inflammatory response predominantly in the extra-abdominal compartments. This illustrates the importance of surgery in prevention of multiple organ failure and denotes the compartmentalized character of the inflammatory response. This polymicrobial model with implicated surgical intervention reflects the clinical situation and may be more appropriate to test therapeutic interventions than a model involving only CLP.