Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Clin Nurs ; 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38979896

RESUMO

AIM(S): To evaluate the incidence of skin-related complications attributable to incontinence-associated dermatitis (IAD) using an external female urinary catheter device strategy for urinary incontinent (UI) patients in acute care. DESIGN: Multicenter quality improvement study. METHODS: Randomized allocation of two commercially available external female urinary catheter devices was used in hospitalized UI female patients. Daily nursing skin assessments were documented in the electronic health record before, during and after external catheter device application. Methods and results were reported following SQUIRE guidelines. RESULTS: Three hundred and eighty-one patients from 57 inpatient care units were included in the analysis. Both catheter devices were associated with an overall low risk (5 %) of new or worsening skin breakdown. CONCLUSION: The overall benefit of external catheters is most persuasive for skin integrity, rather than infection prevention. IMPACT: Significant negative outcomes are associated with UI patients. External female urinary catheters are a non-invasive alternative strategy to reduce exposure of regional skin to urine contamination and IAD-related skin complications. Use of external female urinary catheters in hospitalized UI female patients offers low risk (5%) of new or worsening overall skin breakdown. PATIENT CONTRIBUTION: Hospitalized UI female patients were screened for external catheter device eligibility by the bedside nurse. The quality improvement review committee waved consent because the intervention was considered standard care.

2.
Value Health ; 24(11): 1570-1577, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34711356

RESUMO

OBJECTIVES: To assist with planning hospital resources, including critical care (CC) beds, for managing patients with COVID-19. METHODS: An individual simulation was implemented in Microsoft Excel using a discretely integrated condition event simulation. Expected daily cases presented to the emergency department were modeled in terms of transitions to and from ward and CC and to discharge or death. The duration of stay in each location was selected from trajectory-specific distributions. Daily ward and CC bed occupancy and the number of discharges according to care needs were forecast for the period of interest. Face validity was ascertained by local experts and, for the case study, by comparing forecasts with actual data. RESULTS: To illustrate the use of the model, a case study was developed for Guy's and St Thomas' Trust. They provided inputs for January 2020 to early April 2020, and local observed case numbers were fit to provide estimates of emergency department arrivals. A peak demand of 467 ward and 135 CC beds was forecast, with diminishing numbers through July. The model tended to predict higher occupancy in Level 1 than what was eventually observed, but the timing of peaks was quite close, especially for CC, where the model predicted at least 120 beds would be occupied from April 9, 2020, to April 17, 2020, compared with April 7, 2020, to April 19, 2020, in reality. The care needs on discharge varied greatly from day to day. CONCLUSIONS: The DICE simulation of hospital trajectories of patients with COVID-19 provides forecasts of resources needed with only a few local inputs. This should help planners understand their expected resource needs.


Assuntos
COVID-19/economia , Simulação por Computador/normas , Alocação de Recursos/métodos , Capacidade de Resposta ante Emergências/economia , COVID-19/prevenção & controle , COVID-19/terapia , Humanos , Alocação de Recursos/normas , Capacidade de Resposta ante Emergências/tendências
3.
Mol Syst Biol ; 12(12): 895, 2016 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-27994041

RESUMO

Biological functions are typically performed by groups of cells that express predominantly the same genes, yet display a continuum of phenotypes. While it is known how one genotype can generate such non-genetic diversity, it remains unclear how different phenotypes contribute to the performance of biological function at the population level. We developed a microfluidic device to simultaneously measure the phenotype and chemotactic performance of tens of thousands of individual, freely swimming Escherichia coli as they climbed a gradient of attractant. We discovered that spatial structure spontaneously emerged from initially well-mixed wild-type populations due to non-genetic diversity. By manipulating the expression of key chemotaxis proteins, we established a causal relationship between protein expression, non-genetic diversity, and performance that was theoretically predicted. This approach generated a complete phenotype-to-performance map, in which we found a nonlinear regime. We used this map to demonstrate how changing the shape of a phenotypic distribution can have as large of an effect on collective performance as changing the mean phenotype, suggesting that selection could act on both during the process of adaptation.


Assuntos
Quimiotaxia , Proteínas de Escherichia coli/metabolismo , Escherichia coli/fisiologia , Técnicas Analíticas Microfluídicas/instrumentação , Adaptação Fisiológica , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Modelos Biológicos , Fenótipo
4.
Anaerobe ; 48: 1-6, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28645479

RESUMO

OBJECTIVES: Studies are conflicting regarding the association of the North American pulsed-field gel electrophoresis type 1 (NAP1) strain in Clostridium difficile infection (CDI) and outcomes. We evaluated the association of NAP1 with healthcare-associated CDI disease severity, mortality, and recurrence at our academic medical center. METHODS: Healthcare-associated CDI cases were identified from November 1, 2011 through January 31, 2013. Multivariable regression models were used to evaluate the associations of NAP1 with severe disease (based on the Hines VA severity score index), mortality, and recurrence. RESULTS: Among 5424 stool specimens submitted to the Clinical Microbiology Laboratory, 292 (5.4%) were positive for C. difficile by polymerase chain reaction (PCR) on or after hospital day 4; 70 (24%) of these specimens also tested positive for NAP1. During the study period, 247 (85%) patients had non-severe disease and 45 (15%) patients had severe disease. Among patients with non-severe disease, 65 (26%) had NAP1 and among patients with severe disease, 5 (11%) had NAP1. After controlling for potential confounders, NAP1 was not associated with an increased likelihood of severe disease (adjusted odds ratio [aOR] = 0.35; 95% confidence interval [CI], 0.13-0.93), in-hospital mortality (aOR = 1.02; 95% CI, 0.53-1.96), or recurrence (aOR = 1.16, 95% CI, 0.36-3.77). CONCLUSIONS: The NAP1 strain did not increase disease severity, mortality, or recurrence in this study, although the incidence of NAP1-positive healthcare associated-CDI was low. The role of strain typing in outcomes and treatment selection in patients with healthcare-associated CDI remains uncertain.


Assuntos
Clostridioides difficile/classificação , Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/mortalidade , Infecção Hospitalar/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas de Tipagem Bacteriana , Infecções por Clostridium/microbiologia , Eletroforese em Gel de Campo Pulsado , Fezes/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Fatores de Risco , Resultado do Tratamento , Adulto Jovem
5.
Biochem Soc Trans ; 43(5): 1069-74, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26517925

RESUMO

Inflammation is part of the physiological innate immune response to invading pathogens and tissue injury. However, unresolved inflammation leads to human disease. The tribbles (TRIB) family of pseudokinase proteins has been shown to modulate key inflammatory signalling pathways, including the MAPK (mitogen-activated protein kinase) and PI3K (phosphoinositide 3-kinase) networks. This review summarizes our current knowledge on TRIBs in the context of inflammation, both at the level of molecular mechanisms and in disease development.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas de Ciclo Celular/metabolismo , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Repressoras/metabolismo , Transdução de Sinais , Animais , Humanos , Inflamação/patologia , Modelos Biológicos , Proteínas Serina-Treonina Quinases/metabolismo
6.
Hosp Pharm ; 50(6): 496-504, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26405341

RESUMO

BACKGROUND: Studies evaluating the impact of passive cost visibility tools on antibiotic prescribing are lacking. OBJECTIVE: The objective of this study was to evaluate whether the implementation of a passive antibiotic cost visibility tool would impact antibiotic prescribing and decrease antibiotic spending. METHODS: An efficiency and effectiveness initiative (EEI) was implemented in October 2012. To support the EEI, an antibiotic cost visibility tool was created in June 2013 displaying the relative cost of antibiotics. Using an observational study of interrupted time series design, 3 time frames were studied: pre EEI, post EEI, and post cost visibility tool implementation. The primary outcome was antibiotic cost per 1,000 patient days. Secondary outcomes included case mix index (CMI)-adjusted antibiotic cost per 1,000 patient days and utilization of the cost visibility tool. RESULTS: Initiation of the EEI was associated with a $4,675 decrease in antibiotic cost per 1,000 patient days (P = .003), and costs continued to decrease in the months following EEI (P = .009). After implementation of the cost visibility tool, costs remained stable (P = .844). Despite CMI increasing over time, adjustment for CMI had no impact on the directionality or statistical significance of the results. CONCLUSION: Our study demonstrated a significant and sustained decrease in antibiotic cost per 1,000 patient days when focused medication cost reduction efforts were implemented, but passive cost visibility tool implementation was not associated with additional cost reduction. Antibiotic cost visibility tools may be of most benefit when prior medication cost reduction efforts are lacking or when an active intervention is incorporated.

8.
Ann Pharmacother ; 48(8): 962-969, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24823910

RESUMO

BACKGROUND: Several case reports have documented acute kidney injury (AKI) attributable to antibiotic-impregnated cement (AIC) spacers. OBJECTIVES: To identify AKI risk factors among patients who underwent AIC placement and determine whether vancomycin-AIC placement affects systemic vancomycin dosing. METHODS: Phase 1 was a case-control study to identify AKI risk factors among patients who underwent AIC placement. Cases experienced AKI; controls had unchanged renal function. Phase 2 was a retrospective cohort study. Patients who received ≥72 hours of intravenous (IV) vancomycin were divided into 2 groups according to whether they underwent vancomycin-AIC placement. Primary outcome was number of vancomycin dosing changes. RESULTS: Phase 1: Among 26 cases and 74 controls AKI risk factors on univariate and multivariable analysis included exposure to angiotensin-converting-enzyme (ACE) inhibitor exposure within 7 days of AIC placement (42% vs 20%, P = 0.03) and piperacillin-tazobactam within 7 days following AIC placement (31% vs 12%, P = 0.03). Phase 2: Among 53 patients who underwent vancomycin-AIC placement and 104 who underwent another surgery type, vancomycin was adjusted more frequently in patients who underwent vancomycin-AIC placement (28% vs 15%, P = 0.06). CONCLUSIONS: Among patients who undergo AIC placement with vancomycin and/or tobramycin, exposure to ACE inhibitors and piperacillin-tazobactam are associated with increased risk of AKI in the immediate postoperative period. No empirical adjustments to IV vancomycin dosing are necessary in patients undergoing vancomycin-AIC placement.

9.
Ann Pharmacother ; 47(12): 1712-6, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24259616

RESUMO

OBJECTIVE: To review the literature regarding booster or higher doses of influenza antigen for increasing immunogenicity of inactivated influenza vaccine (IIV) in HIV-infected patients. DATA SOURCES: MEDLINE (1966 to September 2013) was searched using the terms immunize, influenza, vaccine, and HIV or AIDS in combination with two-dose, booster-dose, increased antigen, or high-dose. One trial of booster dosing with standard doses (SDs) of IIV, trivalent (IIV3); 2 trials of booster dosing with intermediate doses (ID) of H1N1 IIV or IIV3; and 1 trial of high-dose (HD) IIV3 were identified. STUDY SELECTION AND DATA EXTRACTION: Trials administering 2-dose, booster-dose, or increased antigen of influenza vaccine to patients with HIV were reviewed. Because adjuvanted IIV is not available and IIV, quadrivalent was recently approved in the United States, studies evaluating these vaccines were excluded. DATA SYNTHESIS: HIV-infected individuals are at high risk for influenza-related complications; however, vaccination with SD IIV may not confer optimal protection. It has been postulated that booster or higher doses of influenza antigen may lead to increased immunogenicity. When ID and SD or ID with boosters were evaluated in HIV-infected patients, significant increases in surrogate markers for influenza protection were not achieved. However, HD IIV3 did result in significant increases in seroprotective antibody levels, though 'clinical' influenza was not evaluated. CONCLUSIONS: Currently, evidence is insufficient to reach conclusions about the efficacy of booster dosing, ID, or HD influenza vaccine in HIV-infected patients. Trials evaluating booster or higher-antigen doses of IIV for 'clinical' influenza are necessary before routinely recommending for HIV-infected patients.


Assuntos
Antígenos Virais/administração & dosagem , Infecções por HIV/terapia , Vacinas contra Influenza/administração & dosagem , Humanos , Imunização Secundária , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas de Produtos Inativados
10.
J Am Chem Soc ; 134(15): 6650-9, 2012 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-22452637

RESUMO

Water nanoparticles play an important role in atmospheric processes, yet their equilibrium and nonequilibrium liquid-ice phase transitions and the structures they form on freezing are not yet fully elucidated. Here we use molecular dynamics simulations with the mW water model to investigate the nonequilibrium freezing and equilibrium melting of water nanoparticles with radii R between 1 and 4.7 nm and the structure of the ice formed by crystallization at temperatures between 150 and 200 K. The ice crystallized in the particles is a hybrid form of ice I with stacked layers of the cubic and hexagonal ice polymorphs in a ratio approximately 2:1. The ratio of cubic ice to hexagonal ice is insensitive to the radius of the water particle and is comparable to that found in simulations of bulk water around the same temperature. Heating frozen particles that contain multiple crystallites leads to Ostwald ripening and annealing of the ice structures, accompanied by an increase in the amount of ice at the expense of the liquid water, before the particles finally melt from the hybrid ice I to liquid, without a transition to hexagonal ice. The melting temperatures T(m) of the nanoparticles are not affected by the ratio of cubic to hexagonal layers in the crystal. T(m) of the ice particles decreases from 255 to 170 K with the particle size and is well described by the Gibbs-Thomson equation, T(m)(R) = T(m)(bulk) - K(GT)/(R - d), with constant K(GT) = 82 ± 5 K·nm and a premelted liquid of width d = 0.26 ± 0.05 nm, about one monolayer. The freezing temperatures also decrease with the particles' radii. These results are important for understanding the composition, freezing, and melting properties of ice and liquid water particles under atmospheric conditions.

11.
Front Cardiovasc Med ; 9: 948461, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36158793

RESUMO

Tribbles 3 (TRIB3) modulates lipid and glucose metabolism, macrophage lipid uptake, with a gain-of-function variant associated with increased cardiovascular risk. Here we set out to examine the role of this pseudokinase in atherosclerotic plaque development. Human endarterectomy atherosclerotic tissue specimens analysed by immunofluorescence showed upregulated TRIB3 in unstable plaques and an enrichment in unstable regions of stable plaques. Atherosclerosis was induced in full body Trib3KO and Trib3WT littermate mice by injecting mPCSK9 expressing adeno-associated virus and western diet feeding for 12 weeks. Trib3KO mice showed expanded visceral adipose depot while circulatory lipid levels remained unaltered compared to wildtype mice. Trib3KO mice aortae showed a reduced plaque development and improved plaque stability, with increased fibrous cap thickness and collagen content, which was accompanied by increased macrophage content. Analysis of both mouse and human macrophages with reduced TRIB3 expression showed elongated morphology, increased actin expression and altered regulation of genes involved in extracellular matrix remodelling. In summary, TRIB3 controls plaque development and may be atherogenic in vivo. Loss of TRIB3 increases fibrous cap thickness via altered metalloproteinase expression in macrophages, thus inhibiting collagen and elastic fibre degradation, suggesting a role for TRIB3 in the formation of unstable plaques.

12.
Theranostics ; 12(8): 3584-3600, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35664073

RESUMO

Molecular mechanisms that regulate tumor-associated macrophage (TAM) phenotype and function are incompletely understood. The pseudokinase TRIB1 has been reported as a regulator of macrophage phenotypes, both in mouse and human systems. Methods: Bioinformatic analysis was used to investigate the link between TRIB1 expression in breast cancer and therapeutic response to chemotherapy. In vivo models of breast cancer included immune-competent mice to characterize the consequences of altered (reduced or elevated) myeloid Trib1 expression on tumor growth and composition of stromal immune cell populations. Results: TRIB1 was highly expressed by TAMs in breast cancer and high TRIB1 expression correlated with response to chemotherapy and patient survival. Both overexpression and knockout of myeloid Trib1 promote mouse breast tumor growth, albeit through different molecular mechanisms. Myeloid Trib1 deficiency led to an early acceleration of tumor growth, paired with a selective reduction in perivascular macrophage numbers in vivo and enhanced oncogenic cytokine expression in vitro. In contrast, elevated levels of Trib1 in myeloid cells led to an increased late-stage mammary tumor volume, coupled with a reduction of NOS2 expressing macrophages and an overall reduction of macrophages in hypoxic tumor regions. In addition, we show that myeloid Trib1 is a previously unknown, negative regulator of the anti-tumor cytokine IL-15, and that increased myeloid Trib1 expression leads to reduced IL-15 levels in mammary tumors, with a consequent reduction in the number of T-cells that are key to anti-tumor immune responses. Conclusions: Together, these results define a key role for TRIB1 in chemotherapy responses for human breast cancer and provide a mechanistic understanding for the importance of the control of myeloid TRIB1 expression in the development of this disease.


Assuntos
Neoplasias da Mama , Macrófagos Associados a Tumor , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Citocinas/metabolismo , Feminino , Humanos , Interleucina-15/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Fenótipo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética
13.
Dev Med Child Neurol ; 53(4): 375-7, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21232056

RESUMO

Retrospective case note audits were undertaken of children with clinically diagnosed cerebral palsy known to paediatricians and physiotherapists in Sunderland (UK). Evidence of brain magnetic resonance imaging (MRI) was recorded, including expert opinions requested, in order to quantify the perceived mismatch between local, general radiological and regional, specialist neuroradiological reporting, towards ensuring the best possible yield to inform clinical practice and accurate information-sharing with families. One hundred and ninety-seven out of 214 (92%) had documented neuroimaging; 111 out of 197 (56.3%) were dual reported. Only 34 out of 111 reports were concordant overall. Sixty per cent of brain MRI reported as normal locally, were found not to be normal on specialist review. Clinicians requesting brain MRI in children with disordered development must be mindful of the expertise of those reporting. Those based in district settings must network closely with specialists in expert centres, if disabled children and young people are to receive equitable care of the highest standard.


Assuntos
Encéfalo/patologia , Paralisia Cerebral/patologia , Imageamento por Ressonância Magnética , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , Adulto Jovem
14.
J Chem Phys ; 133(15): 154516, 2010 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-20969412

RESUMO

The phase behavior of confined water is a topic of intense and current interest due to its relevance in biology, geology, and materials science. Nevertheless, little is known about the phases that water forms even when confined in the simplest geometries, such as water confined between parallel surfaces. Here we use molecular dynamics simulations to compute the phase diagram of two layers of water confined between parallel non hydrogen bonding walls. This study shows that the water bilayer forms a dodecagonal quasicrystal, as well as two previously unreported bilayer crystals, one tiled exclusively by pentagonal rings. Quasicrystals, structures with long-range order but without periodicity, have never before been reported for water. The dodecagonal quasicrystal is obtained from the bilayer liquid through a reversible first-order phase transition and has diffusivity intermediate between that of the bilayer liquid and ice phases. The water quasicrystal and the ice polymorphs based on pentagons are stabilized by compression of the bilayer and are not templated by the confining surfaces, which are smooth. This demonstrates that these novel phases are intrinsically favored in bilayer water and suggests that these structures could be relevant not only for confined water but also for the wetting and properties of water at interfaces.

15.
J Chem Phys ; 132(12): 124511, 2010 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-20370137

RESUMO

Confinement of water usually depresses its melting temperature. Here we use molecular dynamics simulations to determine the liquid-crystal equilibrium temperature for water confined between parallel hydrophobic or mildly hydrophilic plates as a function of the distance between the surfaces. We find that bilayer ice, an ice polymorph in which the local environment of each water molecule strongly departs from the most stable tetrahedral structure, has the highest melting temperature (T(m)) of the series of l-layer ices. The melting temperature of bilayer ice is not only unusually high compared to the other confined ices, but also above the melting point of bulk hexagonal ice. Recent force microscopy experiments of water confined between graphite and a tungsten tip reveal the formation of ice at room temperature [K. B. Jinesh and J. W. M. Frenken, Phys. Rev. Lett. 101, 036101 (2008)]. Our results suggest that bilayer ice, for which we compute a T(m) as high as 310 K in hydrophobic confinement, is the crystal formed in those experiments.

16.
Front Immunol ; 11: 574046, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33329538

RESUMO

The pseudokinase TRIB1 controls cell function in a range of contexts, by regulating MAP kinase activation and mediating protein degradation via the COP1 ubiquitin ligase. TRIB1 regulates polarization of macrophages and dysregulated Trib1 expression in murine models has been shown to alter atherosclerosis burden and adipose homeostasis. Recently, TRIB1 has also been implicated in the pathogenesis of prostate cancer, where it is often overexpressed, even in the absence of genetic amplification. Well described TRIB1 effectors include MAP kinases and C/EBP transcription factors, both in immune cells and in carcinogenesis. However, the mechanisms that regulate TRIB1 itself remain elusive. Here, we show that the long and conserved 3'untranslated region (3'UTR) of TRIB1 is targeted by miRNAs in macrophage and prostate cancer models. By using a systematic in silico analysis, we identified multiple "high confidence" miRNAs potentially binding to the 3'UTR of TRIB1 and report that miR-101-3p and miR-132-3p are direct regulators of TRIB1 expression and function. Binding of miR-101-3p and miR-132-3p to the 3'UTR of TRIB1 mRNA leads to an increased transcription and secretion of interleukin-8. Our data demonstrate that modulation of TRIB1 by miRNAs alters the inflammatory profile of both human macrophages and prostate cancer cells.


Assuntos
Citocinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Macrófagos/metabolismo , MicroRNAs/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Regiões 3' não Traduzidas , Animais , Sítios de Ligação , Linhagem Celular Tumoral , Regulação da Expressão Gênica , Humanos , Inflamação , Interleucina-8/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , MicroRNAs/genética , Fenótipo , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
17.
Nat Commun ; 11(1): 214, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924781

RESUMO

Neutrophils are implicated in the pathogenesis of atherosclerosis but are seldom detected in atherosclerotic plaques. We investigated whether neutrophil-derived microvesicles may influence arterial pathophysiology. Here we report that levels of circulating neutrophil microvesicles are enhanced by exposure to a high fat diet, a known risk factor for atherosclerosis. Neutrophil microvesicles accumulate at disease-prone regions of arteries exposed to disturbed flow patterns, and promote vascular inflammation and atherosclerosis in a murine model. Using cultured endothelial cells exposed to disturbed flow, we demonstrate that neutrophil microvesicles promote inflammatory gene expression by delivering miR-155, enhancing NF-κB activation. Similarly, neutrophil microvesicles increase miR-155 and enhance NF-κB at disease-prone sites of disturbed flow in vivo. Enhancement of atherosclerotic plaque formation and increase in macrophage content by neutrophil microvesicles is dependent on miR-155. We conclude that neutrophils contribute to vascular inflammation and atherogenesis through delivery of microvesicles carrying miR-155 to disease-prone regions.


Assuntos
Aterosclerose/metabolismo , Endotélio/metabolismo , MicroRNAs/metabolismo , Neutrófilos/metabolismo , Animais , Aterosclerose/patologia , Dieta Hiperlipídica , Modelos Animais de Doenças , Células Endoteliais , Endotélio/patologia , Regulação da Expressão Gênica , Humanos , Macrófagos/metabolismo , Camundongos , Camundongos Knockout para ApoE , MicroRNAs/genética , NF-kappa B/metabolismo , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia
18.
J Chem Phys ; 131(14): 144503, 2009 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-19831448

RESUMO

In order to predict accurately the chemical shift of NMR-active nuclei in solid phase systems, magnetic shielding calculations must be capable of considering the complete lattice structure. Here we assess the accuracy of the density functional theory gauge-including projector augmented wave method, which uses pseudopotentials to approximate the nodal structure of the core electrons, to determine the magnetic properties of crystals by predicting the full chemical-shift tensors of all (13)C nuclides in 14 organic single crystals from which experimental tensors have previously been reported. Plane-wave methods use periodic boundary conditions to incorporate the lattice structure, providing a substantial improvement for modeling the chemical shifts in hydrogen-bonded systems. Principal tensor components can now be predicted to an accuracy that approaches the typical experimental uncertainty. Moreover, methods that include the full solid-phase structure enable geometry optimizations to be performed on the input structures prior to calculation of the shielding. Improvement after optimization is noted here even when neutron diffraction data are used for determining the initial structures. After geometry optimization, the isotropic shift can be predicted to within 1 ppm.


Assuntos
Modelos Químicos , Compostos Orgânicos/química , Isótopos de Carbono , Espectroscopia de Ressonância Magnética , Magnetismo , Modelos Moleculares , Conformação Molecular , Movimento (Física) , Teoria Quântica
19.
Sci Adv ; 5(10): eaax9183, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31692955

RESUMO

Macrophages drive atherosclerotic plaque progression and rupture; hence, attenuating their atherosclerosis-inducing properties holds promise for reducing coronary heart disease (CHD). Recent studies in mouse models have demonstrated that Tribbles 1 (Trib1) regulates macrophage phenotype and shows that Trib1 deficiency increases plasma cholesterol and triglyceride levels, suggesting that reduced TRIB1 expression mediates the strong genetic association between the TRIB1 locus and increased CHD risk in man. However, we report here that myeloid-specific Trib1 (mTrib1) deficiency reduces early atheroma formation and that mTrib1 transgene expression increases atherogenesis. Mechanistically, mTrib1 increased macrophage lipid accumulation and the expression of a critical receptor (OLR1), promoting oxidized low-density lipoprotein uptake and the formation of lipid-laden foam cells. As TRIB1 and OLR1 RNA levels were also strongly correlated in human macrophages, we suggest that a conserved, TRIB1-mediated mechanism drives foam cell formation in atherosclerotic plaque and that inhibiting mTRIB1 could be used therapeutically to reduce CHD.


Assuntos
Aterosclerose/metabolismo , Aterosclerose/patologia , Células Espumosas/metabolismo , Células Espumosas/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Células Mieloides/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Colesterol/metabolismo , Modelos Animais de Doenças , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Modelos Biológicos , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Receptores Depuradores Classe E/metabolismo
20.
Nat Commun ; 10(1): 1695, 2019 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-30979898

RESUMO

Actin cytoskeleton is well-known for providing structural/mechanical support, but whether and how it regulates chromatin and cell fate reprogramming is far less clear. Here, we report that MKL1, the key transcriptional co-activator of many actin cytoskeletal genes, regulates genomic accessibility and cell fate reprogramming. The MKL1-actin pathway weakens during somatic cell reprogramming by pluripotency transcription factors. Cells that reprogram efficiently display low endogenous MKL1 and inhibition of actin polymerization promotes mature pluripotency activation. Sustained MKL1 expression at a level seen in typical fibroblasts yields excessive actin cytoskeleton, decreases nuclear volume and reduces global chromatin accessibility, stalling cells on their trajectory toward mature pluripotency. In addition, the MKL1-actin imposed block of pluripotency can be bypassed, at least partially, when the Sun2-containing linker of the nucleoskeleton and cytoskeleton (LINC) complex is inhibited. Thus, we unveil a previously unappreciated aspect of control on chromatin and cell fate reprogramming exerted by the MKL1-actin pathway.


Assuntos
Reprogramação Celular , Cromatina/química , Transativadores/metabolismo , Citoesqueleto de Actina/metabolismo , Animais , Diferenciação Celular , Núcleo Celular/metabolismo , Citoesqueleto/metabolismo , Feminino , Fibroblastos/citologia , Transferência Ressonante de Energia de Fluorescência , Genótipo , Proteínas de Fluorescência Verde/metabolismo , Masculino , Camundongos , Proteínas de Fusão Oncogênica/metabolismo , Células-Tronco Pluripotentes/citologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA