instruction:
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.
question:
The proteasome is a major cellular proteinase. Its activity is modulated by cellular oxidants. Hepatitis C core protein and ethanol exposure both cause enhanced oxidant generation. The aim was to investigate whether core protein, by its ability to generate oxidants, alters proteasome activity and whether these alterations are further affected by ethanol exposure.', 'These interactions were examined in Huh-7 cell lines that expressed inducible HCV core protein and/or constitutive cytochrome P450 2E1 (CYP2E1) and as purified components in a cell-free system. Chymotrypsin-like proteasome activity was measured fluorometrically.', 'Proteasome activity in core-positive 191-20 cells was 20% higher than that in core-negative cells and was enhanced 3-fold in CYP2E1-expressing L14 cells. Exposure of core-positive cells to glutathione ethyl ester, catalase, or the CYP2E1 inhibitor diallyl sulfide partially reversed the elevation of proteasome activity in core-positive cells, whereas ethanol exposure suppressed proteasome activity. The results indicate that proteasome activity was up-regulated by low levels of core-induced oxidative stress but down-regulated by high levels of ethanol-elicited stress. These findings were partially mimicked in a cell-free system. Addition of core protein enhanced the peptidase activity of purified 20S proteasome containing the proteasome activator PA28 and was further potentiated by addition of liver mitochondrial and/or microsome fractions. However, proteasome activation was significantly attenuated when fractions were obtained from ethanol-fed animals.
answer:
Is proteasome activation by hepatitis C core protein reversed by ethanol-induced oxidative stress?


question:
Cancer cells frequently exhibit resistance to the cytotoxic effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Pretreatment of TRAIL-resistant cells with cisplatin sensitizes them to this ligand. Cisplatin also has been shown to enhance adenoviral transgene expression.', 'This study aims to evaluate the ability of cisplatin to enhance the expression and the cytotoxic effect of the tumor-specific adenoviral vector Ad/gTRAIL, which expresses a green fluorescent protein-TRAIL fusion protein.', 'Cultured cancer cells and normal human cells were infected with Ad/gTRAIL with or without cisplatin pretreatment. Adenoviral transgene expression was determined by using flow cytometry to measure green fluorescent protein fluorescence. Cytotoxicity was measured by using thiazolyl blue tetrazolium bromide assays and an apoptosis enzyme-linked immunosorbent assay kit.', 'Green fluorescent protein-TRAIL fusion protein expression was significantly enhanced by cisplatin pretreatment in cancer cells. Cisplatin treatment before Ad/gTRAIL infection resulted in a 2- to 12-fold increase in green fluorescent protein fluorescence intensity across cancer lines. Although Ad/gTRAIL induced mild cytotoxicity in all cancer lines (inhibitory concentration of 50% values of >500 pfu/cell), pretreatment with cisplatin resulted in a dose-dependent enhancement of Ad/gTRAIL-mediated cytotoxicity, as indicated by the drastic reduction of inhibitory concentration of 50% values to 4 to 42 pfu/cell in all cell lines. There was no cytotoxicity noted in normal cells treated with both cisplatin and Ad/gTRAIL.
answer:
Does cisplatin enhance apoptosis induced by a tumor-selective adenovirus expressing tumor necrosis factor-related apoptosis-inducing ligand?


question:
To determine if temporomandibular joint chondrocyte apoptosis is induced in rats with dental biomechanical stimulation and what a role TNF takes.', 'Thirty-two rats were divided into 4 groups (n = 8/group) and exposed to incisor mal-occlusion induced by unilateral anterior crossbite biomechanical stimulation. Two groups were sampled at 2 or 4 weeks. The other two groups were treated with local injections of a TNF inhibitor or PBS into the temporomandibular joints area at 2 weeks and then sampled at 4 weeks. Twenty-four rats either served as unilateral anterior crossbite mock operation controls (n = 8/group) with sampling at 2 or 4 weeks or received a local injection of the TNF inhibitor at 2 weeks with sampling at 4 weeks. Chondrocytes were isolated from the temporomandibular joints of 6 additional rats and treated with TNF in vitro. Joint samples were assessed using Hematoxylin&eosin, Safranin O, TUNEL and immunohistochemistry staining, real-time PCR, fluorogenic activity assays and Western blot analyses. The isolated chondrocytes were also analyzed by flow cytometry.', 'Unilateral anterior crossbite stimulation led to temporomandibular joint cartilage degradation, associated with an increase in TUNEL-positive chondrocytes number, caspase-9 expression levels, and the release of cytochrome c from mitochondria at 2 weeks without changes in TNF and caspase-8 levels until after 4 weeks. TNF stimulated apoptosis of the isolated chondrocytes and up-regulated caspase-8 expression, but did not change caspase-9 expression levels. Local injection of TNF inhibitor down-regulated caspase-8 expression and reduced TUNEL-positive cell number, but did not reverse cartilage thickness reduction, caspase-9 up-regulation or cytochrome c release.
answer:

Does tNF accelerate Death of Mandibular Condyle Chondrocytes in Rats with Biomechanical Stimulation-Induced Temporomandibular Joint Disease?