190 research outputs found

    Molecular regulation of the PAI‐1 gene by hypoxia: contributions of Egr‐1, HIF‐1 α, and C/EBPα

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    Hypoxia, as occurs during tissue ischemia, tips the natural anticoagulant/procoagulant balance of the endovascular wall to favor activation of coagulation. Plasminogen activator inhibitor‐1 (PAI‐1) is an important factor suppressing fibrinolysis under conditions of low oxygen tension. We previously reported that hypoxia induced PAI‐1 mRNA and antigen expression in murine macrophages secondary to increased de novo transcription as well as increased mRNA stability. We now show in RAW264.7 murine macrophages that the transcription factors early growth response gene‐1 (Egr‐1), hypoxia‐inducible factor‐1α (HIF‐1α), and CCAAT/enhancer binding protein α (C/EBPα) are quickly activated in hypoxia and are responsible for transcription and expression of PAI‐1. Murine PAI‐1 promoter constructs, including Egr, HIF‐1α, and/or C/EBPα binding sites, were transfected into RAW 264.7 murine macrophages. To identify the relative importance of each of these putative hypoxia‐responsive elements, cells were exposed to normobaric hypoxia, and transcriptional activity was recorded. At 16 h of hypoxic exposure, murine PAI‐1 promoter deletion constructs that included Egr, HIF‐1α, and/or C/EBPα binding sites demonstrated increased tran‐scriptional activity. Mutation of each of these three murine PAI‐1 promoter sites (or a combination of them) resulted in a marked reduction in hypoxia sensitivity as detected by transcriptional analysis. Functional data obtained using 32P‐labeled Egr, HIF‐1 α response element (HRE), and C/EBPα oligonucleotides revealed induction of DNA binding activity in nuclear extracts from hypoxic RAW cells, with supershift analysis confirming activation of Egr‐1, HIF‐1 α, or C/EBPα. ChIP analysis confirmed the authenticity of these interactions as each of these transcription factors binds to chromatin under hypoxic conditions. Further, the induction of PAI‐1 by Egr‐1, HIF‐1 α, or C/EBPα was replicated in primary peritoneal macrophages. These data suggest that although HIF‐1 α appears to dominate the PAI‐1 transcriptional response in hyp‐oxia, Egr‐1 and C/EBPα greatly augment this response and can do so independent of HIF‐1α or each other. These studies are relevant to ischemic up‐regulation of the PAI‐1 gene and consequent accrual of micro‐vascular thrombus under ischemic conditions.—Liao, H., Hyman, M. C., Lawrence, D. A., Pinsky, D. J. Molecular regulation of the PAI‐1 gene by hypoxia: contributions of Egr‐1, HIF‐1α, and C/EBPα. FASEB J. 21, 935–949 (2007)Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154298/1/fsb2fj066285com.pd

    Images of survival, stories of destruction: Nuclear war on British screens from 1945 to the early 1960s

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    This article discusses a range of depictions and discussions of nuclear war, which appeared on British screens in the first half of the Cold War, in order to understand the changing way nuclear weapons were viewed within British culture. Using such screened images to understand how nuclear war was constructed and represented within British culture, the article argues that the hydrogen bomb, not the atomic bomb, was the true harbinger of the nuclear revolution that transformed cultural understandings of warfare and destruction. Although the atomic bomb created a great deal of anxiety within British popular culture, representations of atomic attack elided atomic destruction with that experienced in 1939-45, emphasising the 'survivability' of atomic war. In the thermonuclear era, the Second World War could not undertake the same symbolic work. The image of the city-destroying bomb was an imaginative as well as technological step-change. Screened representations stressed that a thermonuclear war would literally end the world. As such, they preceded, and indeed provided the cultural climate for, the rise of the Campaign for Nuclear Disarmament (CND). The Campaign exploited and further popularised this idea of the apocalyptic nuclear war as a key aspect of its political and moral standpoint. The article concludes, however, that the cultural hegemony of this vision of nuclear war equally helped underpin notions of nuclear deterrence. The basic assumptions about the nature of nuclear war constructed and circulated on British screens therefore formed part of CND's 'cultural' victory but the article also explains why this did not translate into the political realm. Š Edinburgh University Press

    Dissipationless transport in low density bilayer systems

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    In a bilayer electronic system the layer index may be viewed as the z-component of an isospin-1/2. An XY isospin-ordered ferromagnetic phase was observed in quantum Hall systems and is predicted to exist at zero magnetic field at low density. This phase is a superfluid for opposite currents in the two layers. At B=0 the system is gapless but superfluidity is not destroyed by weak disorder. In the quantum Hall case, weak disorder generates a random gauge field which probably does not destroy superfluidity. Experimental signatures include Coulomb drag and collective mode measurements.Comment: 4 pages, no figures, submitted to Phys. Rev. Let

    A phase II trial of bendamustine in combination with rituximab in older patients with previously untreated diffuse large B-cell lymphoma

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    Bendamustine in combination with rituximab (BR) has been associated with high response rates and acceptable toxicity in older patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Evaluation of BR is warranted in the front-line setting for DLBCL patients not eligible for anthracyclines or for the elderly. In this phase II study, we enrolled DLBCL patients aged ≥65 years who were poor candidates for R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) to determine the efficacy and safety of BR in previously untreated stage II–IV DLBCL. Twenty-three patients were enrolled with a median age of 80 years. 52% of patients presented with poor functional status (Eastern Cooperative Oncology Group performance score of ≥2). The overall response rate was 78% with 12 complete responses (52%). At a median follow up of 29 months, the median overall survival was 10.2 months and the median progression-free survival was 5.4 months. The most common grade 3/4 adverse events were haematological. Combination therapy with BR demonstrates high response rates as front-line therapy in frail older patients with DLBCL, but survival rates were low. BR should be used with caution in future clinical trials involving older DLBCL patients with poor functional status

    Increased mRNA Levels of TCF7L2 and MYC of the Wnt Pathway in Tg-ArcSwe Mice and Alzheimer's Disease Brain

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    Several components in the Wnt pathway, including β-catenin and glycogen synthase kinase 3 beta, have been implied in AD pathogenesis. Here, mRNA brain levels from five-month-old tg-ArcSwe and nontransgenic mice were compared using Affymetrix microarray analysis. With surprisingly small overall changes, Wnt signaling was the most affected pathway with altered expression of nine genes in tg-ArcSwe mice. When analyzing mRNA levels of these genes in human brain, transcription factor 7-like 2 (TCF7L2) and v-myc myelocytomatosis viral oncogene homolog (MYC), were increased in Alzheimer's disease (AD) (P < .05). Furthermore, no clear differences in TCF7L2 and MYC mRNA were found in brains with frontotemporal lobar degeneration, suggesting that altered regulation of these Wnt-related genes could be specific to AD. Finally, mRNA levels of three neurogenesis markers were analyzed. Increased mRNA levels of dihydropyrimidinase-like 3 were observed in AD brain, suggesting that altered Wnt pathway regulation may signify synaptic rearrangement or neurogenesis

    Increased mRNA Levels of TCF7L2 and MYC of the Wnt Pathway in Tg-ArcSwe Mice and Alzheimer's Disease Brain

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    Several components in the Wnt pathway, including β-catenin and glycogen synthase kinase 3 beta, have been implied in AD pathogenesis. Here, mRNA brain levels from five-month-old tg-ArcSwe and nontransgenic mice were compared using Affymetrix microarray analysis. With surprisingly small overall changes, Wnt signaling was the most affected pathway with altered expression of nine genes in tg-ArcSwe mice. When analyzing mRNA levels of these genes in human brain, transcription factor 7-like 2 (TCF7L2) and v-myc myelocytomatosis viral oncogene homolog (MYC), were increased in Alzheimer's disease (AD) (P < .05). Furthermore, no clear differences in TCF7L2 and MYC mRNA were found in brains with frontotemporal lobar degeneration, suggesting that altered regulation of these Wnt-related genes could be specific to AD. Finally, mRNA levels of three neurogenesis markers were analyzed. Increased mRNA levels of dihydropyrimidinase-like 3 were observed in AD brain, suggesting that altered Wnt pathway regulation may signify synaptic rearrangement or neurogenesis

    Study protocol for a type III hybrid effectiveness-implementation trial of strategies to implement firearm safety promotion as a universal suicide prevention strategy in pediatric primary care

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    BACKGROUND: Insights from behavioral economics, or how individuals\u27 decisions and behaviors are shaped by finite cognitive resources (e.g., time, attention) and mental heuristics, have been underutilized in efforts to increase the use of evidence-based practices in implementation science. Using the example of firearm safety promotion in pediatric primary care, which addresses an evidence-to-practice gap in universal suicide prevention, we aim to determine: is a less costly and more scalable behavioral economic-informed implementation strategy (i.e., Nudge ) powerful enough to change clinician behavior or is a more intensive and expensive facilitation strategy needed to overcome implementation barriers? METHODS: The Adolescent and child Suicide Prevention in Routine clinical Encounters (ASPIRE) hybrid type III effectiveness-implementation trial uses a longitudinal cluster randomized design. We will test the comparative effectiveness of two implementation strategies to support clinicians\u27 use of an evidence-based firearm safety practice, S.A.F.E. Firearm, in 32 pediatric practices across two health systems. All pediatric practices in the two health systems will receive S.A.F.E. Firearm materials, including training and cable locks. Half of the practices (k = 16) will be randomized to receive Nudge; the other half (k = 16) will be randomized to receive Nudge plus 1 year of facilitation to target additional practice and clinician implementation barriers (Nudge+). The primary implementation outcome is parent-reported clinician fidelity to the S.A.F.E Firearm program. Secondary implementation outcomes include reach and cost. To understand how the implementation strategies work, the primary mechanism to be tested is practice adaptive reserve, a self-report practice-level measure that includes relationship infrastructure, facilitative leadership, sense-making, teamwork, work environment, and culture of learning. DISCUSSION: The ASPIRE trial will integrate implementation science and behavioral economic approaches to advance our understanding of methods for implementing evidence-based firearm safety promotion practices in pediatric primary care. The study answers a question at the heart of many practice change efforts: which strategies are sufficient to support change, and why? Results of the trial will offer valuable insights into how best to implement evidence-based practices that address sensitive health matters in pediatric primary care. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04844021 . Registered 14 April 2021

    Genome-Wide Association Meta-analysis of Neuropathologic Features of Alzheimer's Disease and Related Dementias

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    Alzheimer's disease (AD) and related dementias are a major public health challenge and present a therapeutic imperative for which we need additional insight into molecular pathogenesis. We performed a genome-wide association study and analysis of known genetic risk loci for AD dementia using neuropathologic data from 4,914 brain autopsies. Neuropathologic data were used to define clinico-pathologic AD dementia or controls, assess core neuropathologic features of AD (neuritic plaques, NPs; neurofibrillary tangles, NFTs), and evaluate commonly co-morbid neuropathologic changes: cerebral amyloid angiopathy (CAA), Lewy body disease (LBD), hippocampal sclerosis of the elderly (HS), and vascular brain injury (VBI). Genome-wide significance was observed for clinico-pathologic AD dementia, NPs, NFTs, CAA, and LBD with a number of variants in and around the apolipoprotein E gene (APOE). GalNAc transferase 7 (GALNT7), ATP-Binding Cassette, Sub-Family G (WHITE), Member 1 (ABCG1), and an intergenic region on chromosome 9 were associated with NP score; and Potassium Large Conductance Calcium-Activated Channel, Subfamily M, Beta Member 2 (KCNMB2) was strongly associated with HS. Twelve of the 21 non-APOE genetic risk loci for clinically-defined AD dementia were confirmed in our clinico-pathologic sample: CR1, BIN1, CLU, MS4A6A, PICALM, ABCA7, CD33, PTK2B, SORL1, MEF2C, ZCWPW1, and CASS4 with 9 of these 12 loci showing larger odds ratio in the clinico-pathologic sample. Correlation of effect sizes for risk of AD dementia with effect size for NFTs or NPs showed positive correlation, while those for risk of VBI showed a moderate negative correlation. The other co-morbid neuropathologic features showed only nominal association with the known AD loci. Our results discovered new genetic associations with specific neuropathologic features and aligned known genetic risk for AD dementia with specific neuropathologic changes in the largest brain autopsy study of AD and related dementias

    Action Without Awareness: Reaching to an Object You Do Not Remember Seeing

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    BACKGROUND: Previous work by our group has shown that the scaling of reach trajectories to target size is independent of obligatory awareness of that target property and that "action without awareness" can persist for up to 2000 ms of visual delay. In the present investigation we sought to determine if the ability to scale reaching trajectories to target size following a delay is related to the pre-computing of movement parameters during initial stimulus presentation or the maintenance of a sensory (i.e., visual) representation for on-demand response parameterization. METHODOLOGY/PRINCIPAL FINDINGS: Participants completed immediate or delayed (i.e., 2000 ms) perceptual reports and reaching responses to different sized targets under non-masked and masked target conditions. For the reaching task, the limb associated with a trial (i.e., left or right) was not specified until the time of response cuing: a manipulation that prevented participants from pre-computing the effector-related parameters of their response. In terms of the immediate and delayed perceptual tasks, target size was accurately reported during non-masked trials; however, for masked trials only a chance level of accuracy was observed. For the immediate and delayed reaching tasks, movement time as well as other temporal kinematic measures (e.g., times to peak acceleration, velocity and deceleration) increased in relation to decreasing target size across non-masked and masked trials. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that speed-accuracy relations were observed regardless of whether participants were aware (i.e., non-masked trials) or unaware (i.e., masked trials) of target size. Moreover, the equivalent scaling of immediate and delayed reaches during masked trials indicates that a persistent sensory-based representation supports the unconscious and metrical scaling of memory-guided reaching
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