instruction:
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.
question:
Context: Magnetic fields have been shown to affect cell proliferation and growth factor expression in cultured cells. Although the activation of endorphin systems is a recurring motif among the biological events elicited by magnetic fields, compelling evidence indicating that magnetic fields may modulate opioid gene expression is still lacking. We therefore investigated whether extremely low frequency (ELF) pulsed magnetic fields (PMF) may affect opioid peptide gene expression and the signaling pathways controlling opioid peptide gene transcription in the adult ventricular myocyte, a cell type behaving both as a target and as a source for opioid peptides.', 'Prodynorphin gene expression was investigated in adult rat myocytes exposed to PMF by the aid of RNase protection and nuclear run-off transcription assays. In PMF-exposed nuclei, nuclear protein kinase C (PKC) activity was followed by measuring the phosphorylation rate of the acrylodan-labeled MARCKS peptide. The effect of PMF on the subcellular distribution of different PKC isozymes was assessed by immunoblotting. A radioimmunoassay procedure coupled to reversed-phase high performance liquid chromatography was used to monitor the expression of dynorphin B.', 'Here, we show that PMF enhanced myocardial opioid gene expression and that a direct exposure of isolated myocyte nuclei to PMF markedly enhanced prodynorphin gene transcription, as in the intact cell. The PMF action was mediated by nuclear PKC activation but occurred independently from changes in PKC isozyme expression and enzyme translocation. PMF also led to a marked increase in the synthesis and secretion of dynorphin B.
Answer: The present findings demonstrate that an opioid gene is activated by myocyte exposure to PMF and that the cell nucleus and nuclear embedded PKC are a crucial target for the PMF action. Due to the wide ranging importance of opioid peptides in myocardial cell homeostasis, the current data may suggest consideration for potential biological effects of PMF in the cardiovascular system.
answer:
Do elf-pulsed magnetic fields modulate opioid peptide gene expression in myocardial cells?

question:
Context: Material loss at the taper junction of metal-on-metal total hip arthroplasties has been implicated in their early failure. The mechanisms of material loss are not fully understood; analysis of the patterns of damage at the taper can help us better understand why material loss occurs at this junction.', 'We mapped the patterns of material loss in a series of 155 metal-on-metal total hip arthroplasties received at our center by scanning the taper surface using a roundness-measuring machine. We examined these material loss maps to develop a 5-tier classification system based on visual differences between different patterns. We correlated these patterns to surgical, implant, and patient factors known to be important for head-stem taper damage.', 'We found that 63 implants had "minimal damage" at the taper (material loss <1 mm
Answer: These material loss maps allow us to suggest different mechanisms that dominate the cause of the material loss in each pattern: (1) corrosion, (2) mechanically assisted corrosion, or (3) intraoperative damage or poor size tolerances leading to toggling of trunnion in taper.
answer:
Does damage Patterns at the Head-Stem Taper Junction help Understand the Mechanisms of Material Loss?

question:
Context: To determine the inhibitory effect of miRNA-381 on renal carcinoma invasion and to explore the underlying mechanisms.
', 'After up-regulation of miRNA-381, the inhibitory effect of miR-381 on cell invasion was investigated. We screened the target genes of miRNA-381 in a database (starBase) through combination of five programs including targetscan, picTar, RNA22, PITA and miRanda. Then, the predicted targeting genes were verified by the dual luciferase reporter assay. We also examined the expression of miRNA-381 and its target genes in renal cancer cells and tissues.
', "Transfection and up-regulation of miRNA-381 resulted in a significant decrease in trans-membrane cell numbers and the ability of renal cell invasion. Bioinformatics analysis showed that CREB binding protein (CBP), -catenin and lymphoid enhancer binding factor-1 (LEF-1) were the potential targets of miRNA-381. In the luciferase reporter gene system, co-transfection of miRNA-381 with the 3'UTR of wild-type target gene led to a significant decrease in luciferase activity. The expression of miRNA-381 was decreased in various renal cancer cells, and it was particularly lower in highly metastatic cell lines (786-OHM). On the contrary, the expression levels of miRNA-381 target genes (CBP, -catenin and LEF-1) were significantly increased in cells and tissues.

Answer: MiRNA-381 can inhibit cell invasion in renal cancer by block the function of CBP, -catenin and LEF-1.
answer:
Does [ MiRNA-381 inhibit the invasion of renal carcinoma and the underlying mechanisms ]?