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.

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.
Do elf-pulsed magnetic fields modulate opioid peptide gene expression in myocardial cells?

Context: Women diagnosed with pregnancy-associated breast cancer postpartum have a worse prognosis, stage for stage, than other women with breast cancer. The time of breast involution is tumor promotional. The extracellular matrix protein tenascin-C is upregulated during involution in animal models and promotes breast cancer progression. It interacts with transforming growth factor (TGF), which also is involved in breast involution and breast cancer progression. Little is known about the expression of tenascin-C during human breast involution, nor its relationship to TGF. The purpose of this study was to investigate the expression of tenascin-C throughout lactation, as well as its relationship to TGF1 and TGF2.', 'Three milk samples from 25 lactating women (transitional, whole, and wean) were collected, separated into components (cells, fat, and skim), and the skim fraction analyzed for total protein, tenascin-C, TGF1, and TGF2. Tenascin-C, TGF1, and TGF2 were detectable in all milk samples.', 'Highest tenascin-C levels on average were found in whole milk, whereas highest mean TGF1 and TGF2 levels were in wean milk. Wean samples on average had higher levels of both TGF1 (26%) and TGF2 (>500%) than matched transitional milk samples. Tenascin-C levels in wean milk were associated with nursing length (p = 0.048). Combining all three milk collection time points, tenascin-C exhibited a weak inverse correlation with TGF1 and TGF2 (p < 0.1). The inverse correlation at the wean time point was stronger for TGF2 than -1 (-0.37 versus -0.25). Tenascin-C, a protein known to promote breast cancer progression, is expressed throughout lactation.
Answer: The inverse correlation with TGF2 in wean milk suggests a possible interaction during breast involution, which should be further investigated.
Does expression of the Extracellular Matrix Protein Tenascin-C vary During Lactation?

Context: Removal of a humeral component during revision shoulder arthroplasty can be difficult. If the component cannot be extracted from above, an alternative approach may compromise bone integrity. Two potential solutions are a humeral window and a longitudinal split. This review was performed to determine complications and outcomes associated with these osteotomies during revision arthroplasty.', 'We reviewed records of 427 patients undergoing revision shoulder arthroplasty, identifying those requiring a window or longitudinal split. Outcomes were intraoperative and postoperative complications, rate of healing, and security of implant fixation.', 'Twenty-six patients underwent creation of a window. Six intraoperative fractures were documented: 5 in greater tuberosity and 1 in humeral shaft. At radiographic follow-up, 23 of 26 windows healed; 2 patients had limited follow-up, and 1 did not have follow-up at our institution. Nineteen patients underwent longitudinal osteotomy. One had intraoperative fracture in greater tuberosity. At radiographic follow-up, 17 of 19 longitudinal splits healed; 1 had limited radiographic follow-up, and 1 did not have follow-up at our institution. Three patients underwent formation of both window and longitudinal osteotomy. At radiographic follow-up, all shoulders healed, and there were no intraoperative or postoperative fractures or malunions.
Answer: In both groups, there were no cases of malunion or clinical loosening. These data suggest that windows and longitudinal splits facilitate controlled removal of well-fixed components with high rate of union and low rate of intraoperative or postoperative sequelae.
Does humeral windows and longitudinal split for component removal in revision shoulder arthroplasty?