185 research outputs found
MAP3K4/CBP-Regulated H2B Acetylation Controls Epithelial-Mesenchymal Transition in Trophoblast Stem Cells
Epithelial stem cells self-renew while maintaining multipotency, but the dependence of stem cell properties on maintenance of the epithelial phenotype is unclear. We previously showed that trophoblast stem (TS) cells lacking the protein kinase MAP3K4 maintain properties of both stemness and epithelial-mesenchymal transition (EMT). Here, we show that MAP3K4 controls the activity of the histone acetyltransferase CBP, and that acetylation of histones H2A and H2B by CBP is required to maintain the epithelial phenotype. Combined loss of MAP3K4/CBP activity represses expression of epithelial genes and causes TS cells to undergo EMT while maintaining their self-renewal and multipotency properties. The expression profile of MAP3K4 deficient TS cells defines an H2B acetylation regulated gene signature that closely overlaps with that of human breast cancer cells. Taken together, our data define an epigenetic switch that maintains the epithelial phenotype in TS cells and reveal previously unrecognized genes potentially contributing to breast cancer
The effectiveness of metal on metal hip resurfacing: a systematic review of the available evidence published before 2002
BACKGROUND: Conventional total hip replacement (THR) may be felt to carry too high a risk of failure over a patient's lifetime, especially in young people. There is increasing interest in metal on metal hip resurfacing arthroplasty (MoM) as this offers a bone-conserving option for treating those patients who are not considered eligible for THR. We aim to evaluate the effectiveness of MoM for treatment of hip disease, and compare it with alternative treatments for hip disease offered within the UK. METHODS: A systematic review was carried out to identify the relevant literature on MoM published before 2002. As watchful waiting and total hip replacement are alternative methods commonly used to alleviate the symptoms of degenerative joint disease of the hip, we compared MoM with these. RESULTS: The data on the effectiveness of MoM are scarce, as it is a relatively new technique and at present only short-term results are available. CONCLUSION: It is not possible to make any firm conclusions about the effectiveness of MoM based on these early results. While the short-term results are promising, it is unclear if such results would be replicated in more rigorous studies, and what the long-term performance might be. Further research is needed which ideally should involve long-term randomised comparisons of MoM with alternative approaches to the clinical management of hip disease
Spatializing the Ecological Leviathan: Territorial Strategies and the Production of Regional Natures
This paper explores a dual absence – the absence of the state within contemporary geographical analyses of nature; and the absence of nature within contemporary explorations of state power. We argue that the modern state continues to play a crucial role in framing social interactions with nature, while nature is still vital to states within their realization of different forms of material and ideological power. In order to reconnect analyses of the state and nature, this paper combines work on the production of nature and state strategy with Lefebvre’s recently translated writings on state space and territory. By focusing on the production of territory (or state space), we explore the interaction of the state and nature in the context of the political management of social and ecological space. We unravel the spatial entanglements of the state and nature through an analysis of the British state’s territorial strategies within the West Midlands region. By considering three key historical periods within the history of the West Mid-lands we reveal how the emergence of the regional space called the West Midlands is a product of the ongoing spatial dialectics of state and nature therein
The Plant Pathogen Pseudomonas syringae pv. tomato Is Genetically Monomorphic and under Strong Selection to Evade Tomato Immunity
Recently, genome sequencing of many isolates of genetically monomorphic bacterial human pathogens has given new insights into pathogen microevolution and phylogeography. Here, we report a genome-based micro-evolutionary study of a bacterial plant pathogen, Pseudomonas syringae pv. tomato. Only 267 mutations were identified between five sequenced isolates in 3,543,009 nt of analyzed genome sequence, which suggests a recent evolutionary origin of this pathogen. Further analysis with genome-derived markers of 89 world-wide isolates showed that several genotypes exist in North America and in Europe indicating frequent pathogen movement between these world regions. Genome-derived markers and molecular analyses of key pathogen loci important for virulence and motility both suggest ongoing adaptation to the tomato host. A mutational hotspot was found in the type III-secreted effector gene hopM1. These mutations abolish the cell death triggering activity of the full-length protein indicating strong selection for loss of function of this effector, which was previously considered a virulence factor. Two non-synonymous mutations in the flagellin-encoding gene fliC allowed identifying a new microbe associated molecular pattern (MAMP) in a region distinct from the known MAMP flg22. Interestingly, the ancestral allele of this MAMP induces a stronger tomato immune response than the derived alleles. The ancestral allele has largely disappeared from today's Pto populations suggesting that flagellin-triggered immunity limits pathogen fitness even in highly virulent pathogens. An additional non-synonymous mutation was identified in flg22 in South American isolates. Therefore, MAMPs are more variable than expected differing even between otherwise almost identical isolates of the same pathogen strain
Dynamic Reprogramming of the Kinome in Response to Targeted MEK Inhibition in Triple-Negative Breast Cancer
Kinase inhibitors have limited success in cancer treatment because tumors circumvent their action. Using a quantitative proteomics approach, we assessed kinome activity in response to MEK inhibition in triple negative breast cancer (TNBC) cells and genetically engineered mice (GEMMs). MEK inhibition caused acute ERK activity loss, resulting in rapid c-Myc degradation that induced expression and activation of several receptor tyrosine kinases (RTKs). RNAi knockdown of ERK or c-Myc mimicked RTK induction by MEK inhibitors, whereas prevention of proteasomal c-Myc degradation blocked kinome reprogramming. MEK inhibitor-induced RTK stimulation overcame MEK2 but not MEK1 inhibition, reactivating ERK and producing drug resistance. The C3Tag GEMM for TNBC similarly induced RTKs in response to MEK inhibition. The inhibitor-induced RTK profile suggested a kinase inhibitor combination therapy that produced GEMM tumor apoptosis and regression where single agents were ineffective. This approach defines mechanisms of drug resistance, allowing rational design of combination therapies for cancer
The Impact of ICT Usage, Workplace Organisation and Human Capital on the Provision of Apprenticeship Training: A Firm-Level Analysis Based on Swiss Panel Data
Firstly, we investigated the determinants of a) the propensity of Swiss firms to provide apprenticeship training, and b) the intensity of training (measured by the employment share of apprentices). We primarily were interested in the relevance as explanatory factors of the three constituent elements of the new firm paradigm that emerged in the course of the last twenty years: intensive usage of ICT; redesign of workplace organisation; shift from lower to higher skills. We found that the skill composition of the workforce (including further training), ICT intensity and, to a lesser extent, workplace organisation are important drivers of apprenticeshipbased skill formation, with stronger effects on training propensity than on training intensity. Secondly, we analysed the relationship between apprenticeship training and firm performance. It turned out that productivity and apprenticeships (training propensity or intensity) are negatively correlated. The study is relevant for training policy in advanced economies where the new firm paradigm plays a large and growing role
Comment letters to the National Commission on Commission on Fraudulent Financial Reporting, 1987 (Treadway Commission) Vol. 2
https://egrove.olemiss.edu/aicpa_sop/1662/thumbnail.jp
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