TASK DEFINITION: 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.
PROBLEM: Context: Obstructive sleep apnea (OSA) is a common disorder characterized by chronic intermittent hypoxia (CIH). OSA is prevalent in obese subjects and is associated with endothelial dysfunction and cardiovascular disorders. We tested the hypothesis that the deleterious effects of IH could be further modulated by diet-induced obesity.', 'Thirty adult (8-10 weeks) male C57BL/6J mice were divided into four groups. Mice were subjected to CIH or intermittent air (IA) for 12h a day and fed either a high fat (HF) or a low fat control diet (CD) for 6weeks. We analyzed endothelial function using a wire myograph, and measured markers of oxidative stress (plasma malondialdehyde (MDA) and total antioxidant capacity (TAC)) using colorimetrical assays. We also measured C-reactive protein (CRP) using ELISA and endothelial nitric oxide (eNOS) gene expression using real time PCR.', 'Stimulated endothelial dependent dilation was significantly impaired only in the group fed high fat diet and subjected to CIH (Emax: HFIH 78±2%, p<0.0001) when compared to the other groups (Emax: HFIA 95±0.7%, CDIH 94±2%, CDIA 97±1%). Also basal endothelial dependant dilation was attenuated in the HFIH group compared to the HFIA group (Emax: HFIH: 179±10% vs. HFIA: 149±11% in the presence of L-NAME). Levels of MDA were elevated in the CDIH group when compared to CDIA (0.68±0.04 vs. 0.41±0.03 μM, p<0.05) but were greatest in the HFIH group (0.83±0.08 μM, p<0.05). However, there was no significant increase in MDA levels in the HFIA group (0.45±0.03 μM, p=NS) when compared to all other groups. Similar effects were observed with CRP levels; CRP levels were significantly higher in the CDIH group compared with intermittent air (10.39±0.38 vs. 8.70±0.21 μg/ml, p<0.05) but the HFIH had the greatest levels of CRP (11.87±0.31 μg/ml, p<0.05). In the HFIA group, CRP levels were not elevated (9.96±0.37 μg/ml, p=NS). Nevertheless, total antioxidant capacity and eNOS gene expression were not significantly different in the groups.\Question: Does chronic intermittent hypoxia cause endothelial dysfunction in a mouse model of diet-induced obesity?

SOLUTION: CIH caused endothelial dysfunction in mice fed an obesogenic diet. Inflammation and oxidative stress were increased in CIH and an obesogenic diet exacerbated these effects.

PROBLEM: Context: Transient receptor potential ankyrin 1 (TRPA1) is a membrane-associated cation channel, widely expressed in neuronal cells and involved in nociception and neurogenic inflammation. We showed recently that TRPA1 mediates cartilage degradation and joint pain in the MIA-model of osteoarthritis (OA) suggesting a hitherto unknown role for TRPA1 in OA. Therefore, we aimed to investigate whether TRPA1 is expressed and functional in human OA chondrocytes.', 'Expression of TRPA1 in primary human OA chondrocytes was assessed by qRT-PCR and Western blot. The functionality of the TRPA1 channel was assessed by Ca(2+)-influx measurements. Production of MMP-1, MMP-3, MMP-13, IL-6, and PGE2 subsequent to TRPA1 activation was measured by immunoassay.', 'We show here for the first time that TRPA1 is expressed in primary human OA chondrocytes and its expression is increased following stimulation with inflammatory factors IL-1β, IL-17, LPS, and resistin. Further, the TRPA1 channel was found to be functional, as stimulation with the TRPA1 agonist AITC caused an increase in Ca(2+) influx, which was attenuated by the TRPA1 antagonist HC-030031. Genetic depletion and pharmacological inhibition of TRPA1 downregulated the production of MMP-1, MMP-3, MMP-13, IL-6, and PGE2 in osteoarthritic chondrocytes and murine cartilage, respectively.\Question: Is transient receptor potential ankyrin 1 ( TRPA1 ) functionally expressed in primary human osteoarthritic chondrocytes?

SOLUTION: The TRPA1 cation channel was found to be functionally expressed in primary human OA chondrocytes, which is an original finding. The presence and inflammatory and catabolic effects of TRPA1 in human OA chondrocytes propose a highly intriguing role for TRPA1 as a pathogenic factor and drug target in OA.

PROBLEM: Context: We have performed TNF-alpha gene transfection in a mouse mammary cancer line and found significant antitumor effects. We hypothesize that the antitumor effects observed in this model are mediated by ICAM-1 and by the recruitment of CD4+ and CD8+ T cells. In vivo (Balb/c mice) tumor growth inhibition, treatment of established tumor and the effects of ICAM-1 and CD4+ and CD8+ T cells were evaluated.', 'Gene transfection with highly efficient vectors resulted in secretion of large amounts of TNF-alpha (ELISA). In vivo antitumor effects were tested. The number of cells required to generate palpable tumor 7-10 days after subcutaneous injection was determined (1 x 10(6)). The same number of transfected cells were injected subcutaneously and compared to nontransfected controls. Tumors were measured blindly and size was analyzed on day 30 by the Wilcoxon rank sum test. Mean tumor size after injection of transfected cells is compared to that of controls. Control tumors reached the maximum allowable size by day 30 (4 cm(2)). On day 30 EMT6-TNF-alpha tumors were 0.48 cm(2) (p < 0.05). The effect of repeat injection (challenge was also tested. Animals were injected with transfected cells or wild-type control on day -6 and challenged with the same number of wild-type tumor cells on day 0. Significant immune protection against subsequent challenge was seen after first time injection with EMT6-TNF-alpha but not after first time EMT6 wild-type injection (1.62 vs. 4 cm(2)). Treatment of 6-day-old tumor was also evaluated. On day 30, mean tumor size in animals treated with EMT6-TNF-alpha was 0.9 cm(2) compared to 4 cm(2) for controls. In all experiments, CD8+ T cell depletion and CD4+ T cell depletion caused a reversal of TNF-alpha-induced inhibitory effects. In addition, in vivo antibody blocking of ICAM-1 in tumor growth experiments reversed antitumor effects (control 4 cm(2), TNF-alpha 0.2 cm(2) and ICAM-1 blocking 3.14 cm(2)). Using flow cytometry, MHC class I and II and ICAM-1 adhesion molecule expression of transfected tumor was tested. ICAM-I expression was significantly upregulated. MHC class II antigen expression was also increased. TNF-alpha-transfected human breast cancer was also evaluated. Three cell lines and fresh tumor were transfected to express TNF-alpha. In vitro analysis revealed ICAM-1 upregulation following transfection. Histologic analysis and immunohistochemical staining revealed TNF-alpha and ICAM-1 in transfected tumors and not in wild-type tumors.\Question: Is treatment of established tumor associated with ICAM-1 upregulation and reversed by CD8 depletion in a tumor necrosis factor-alpha gene transfected mouse mammary tumor?

SOLUTION:
Highly significant in vivo tumor growth inhibition and immune protection after injection with TNF-alpha-transfected tumors appears to be mediated predominantly by CD8+ T cells and ICAM-1 upregulation. These findings suggest that TNF-alpha increases recruitment and adhesion of effector T cells.