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1.
PLoS One ; 16(2): e0246427, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33529266

RESUMO

BACKGROUND: The COVID-19 pandemic has yielded an unprecedented quantity of new publications, contributing to an overwhelming quantity of information and leading to the rapid dissemination of less stringently validated information. Yet, a formal analysis of how the medical literature has changed during the pandemic is lacking. In this analysis, we aimed to quantify how scientific publications changed at the outset of the COVID-19 pandemic. METHODS: We performed a cross-sectional bibliometric study of published studies in four high-impact medical journals to identify differences in the characteristics of COVID-19 related publications compared to non-pandemic studies. Original investigations related to SARS-CoV-2 and COVID-19 published in March and April 2020 were identified and compared to non-COVID-19 research publications over the same two-month period in 2019 and 2020. Extracted data included publication characteristics, study characteristics, author characteristics, and impact metrics. Our primary measure was principal component analysis (PCA) of publication characteristics and impact metrics across groups. RESULTS: We identified 402 publications that met inclusion criteria: 76 were related to COVID-19; 154 and 172 were non-COVID publications over the same period in 2020 and 2019, respectively. PCA utilizing the collected bibliometric data revealed segregation of the COVID-19 literature subset from both groups of non-COVID literature (2019 and 2020). COVID-19 publications were more likely to describe prospective observational (31.6%) or case series (41.8%) studies without industry funding as compared with non-COVID articles, which were represented primarily by randomized controlled trials (32.5% and 36.6% in the non-COVID literature from 2020 and 2019, respectively). CONCLUSIONS: In this cross-sectional study of publications in four general medical journals, COVID-related articles were significantly different from non-COVID articles based on article characteristics and impact metrics. COVID-related studies were generally shorter articles reporting observational studies with less literature cited and fewer study sites, suggestive of more limited scientific support. They nevertheless had much higher dissemination.


Assuntos
Bibliometria , Publicações Periódicas como Assunto , Comunicação , Estudos Transversais , Humanos , Pandemias , Revisão da Pesquisa por Pares , Publicações Periódicas como Assunto/normas , Análise de Componente Principal
2.
Artigo em Inglês | MEDLINE | ID: mdl-33296269

RESUMO

Inflammasomes are multi-protein complexes tasked with sensing endogenous or exogenous inflammatory signals, and integrating this signal into a downstream response. Inflammasome activation has been implicated in a variety of pulmonary diseases, including pulmonary hypertension, bacterial pneumonia, COPD and asthma. Of increasing interest is the contribution of inflammasome activation in the context of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Inflammasome activation in both the lung parenchyma and resident immune cells generates intereukin-1ß (IL-1ß) and IL-18, both of which drive the cascade of lung inflammation forward. Blockade of these responses has been shown to be beneficial in animal models, and is a focus of translational research in the field. In this review, we will discuss the assembly and regulation of inflammasomes during lung inflammation, highlighting therapeutically-viable effector steps. We will examine the importance of IL-1ß and IL-18, two key products of inflammasome activation, in ALI, as well as the contribution of the pulmonary endothelial cell to this process. Finally, we will explore translational research moving toward anti-inflammasome therapies for ALI/ARDS, and speculate toward future directions for the field.

3.
Arterioscler Thromb Vasc Biol ; : ATVBAHA120314557, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33054399

RESUMO

OBJECTIVE: LDL (low-density lipoprotein) transcytosis across the endothelium is performed by the SR-BI (scavenger receptor class B type 1) receptor and contributes to atherosclerosis. HMGB1 (high mobility group box 1) is a structural protein in the nucleus that is released by cells during inflammation; extracellular HMGB1 has been implicated in advanced disease. Whether intracellular HMGB1 regulates LDL transcytosis through its nuclear functions is unknown. Approach and Results: HMGB1 was depleted by siRNA in human coronary artery endothelial cells, and transcytosis of LDL was measured by total internal reflection fluorescence microscopy. Knockdown of HMGB1 attenuated LDL transcytosis without affecting albumin transcytosis. Loss of HMGB1 resulted in reduction in SR-BI levels and depletion of SREBP2 (sterol regulatory element-binding protein 2)-a transcription factor upstream of SR-BI. The effect of HMGB1 depletion on LDL transcytosis required SR-BI and SREBP2. Overexpression of HMGB1 caused an increase in LDL transcytosis that was unaffected by inhibition of extracellular HMGB1 or depletion of RAGE (receptor for advanced glycation endproducts)-a cell surface receptor for HMGB1. The effect of HMGB1 overexpression on LDL transcytosis was prevented by knockdown of SREBP2. Loss of HMGB1 caused a reduction in the half-life of SREBP2; incubation with LDL caused a significant increase in nuclear localization of HMGB1 that was dependent on SR-BI. Animals lacking endothelial HMGB1 exhibited less acute accumulation of LDL in the aorta 30 minutes after injection and when fed a high-fat diet developed fewer fatty streaks and less atherosclerosis. CONCLUSIONS: Endothelial HMGB1 regulates LDL transcytosis by prolonging the half-life of SREBP2, enhancing SR-BI expression. Translocation of HMGB1 to the nucleus in response to LDL requires SR-BI.

4.
Cells ; 9(11)2020 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-33105588

RESUMO

Perivascular inflammation is a prominent pathologic feature in most animal models of pulmonary hypertension (PH) as well as in pulmonary arterial hypertension (PAH) patients. Accumulating evidence suggests a functional role of perivascular inflammation in the initiation and/or progression of PAH and pulmonary vascular remodeling. High levels of cytokines, chemokines, and inflammatory mediators can be detected in PAH patients and correlate with clinical outcome. Similarly, multiple immune cells, including neutrophils, macrophages, dendritic cells, mast cells, T lymphocytes, and B lymphocytes characteristically accumulate around pulmonary vessels in PAH. Concomitantly, vascular and parenchymal cells including endothelial cells, smooth muscle cells, and fibroblasts change their phenotype, resulting in altered sensitivity to inflammatory triggers and their enhanced capacity to stage inflammatory responses themselves, as well as the active secretion of cytokines and chemokines. The growing recognition of the interaction between inflammatory cells, vascular cells, and inflammatory mediators may provide important clues for the development of novel, safe, and effective immunotargeted therapies in PAH.

5.
Nat Commun ; 11(1): 4561, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917873

RESUMO

The protein high-mobility group box 1 (HMGB1) is released into the extracellular space in response to many inflammatory stimuli, where it is a potent signaling molecule. Although research has focused on downstream HMGB1 signaling, the means by which HMGB1 exits the cell is controversial. Here we demonstrate that HMGB1 is not released from bone marrow-derived macrophages (BMDM) after lipopolysaccharide (LPS) treatment. We also explore whether HMGB1 is released via the pore-forming protein gasdermin D after inflammasome activation, as is the case for IL-1ß. HMGB1 is only released under conditions that cause cell lysis (pyroptosis). When pyroptosis is prevented, HMGB1 is not released, despite inflammasome activation and IL-1ß secretion. During endotoxemia, gasdermin D knockout mice secrete HMGB1 normally, yet secretion of IL-1ß is completely blocked. Together, these data demonstrate that in vitro HMGB1 release after inflammasome activation occurs after cellular rupture, which is probably inflammasome-independent in vivo.


Assuntos
Proteína HMGB1/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Macrófagos/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Animais , Modelos Animais de Doenças , Endotoxemia/metabolismo , Feminino , Proteína HMGB1/genética , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Lipopolissacarídeos/efeitos adversos , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas de Ligação a Fosfato/genética , Piroptose , Transdução de Sinais
6.
Can J Anaesth ; 67(12): 1814-1823, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32720256

RESUMO

PURPOSE: Under times of supply chain stress, the availability of some medical equipment and supplies may become limited. The current pandemic involving severe acute respiratory syndrome coronavirus 2 has highlighted limitations to the ordinary provision of personal protective equipment (PPE). For perioperative healthcare workers, N95 masks provide a stark example of PPE in short supply necessitating the creation of scientifically valid protocols for their decontamination and reuse. METHODS: We performed a systematic literature search of MEDLINE, Embase, Cochrane CENTRAL databases, and ClinicalTrials.gov to identify peer-reviewed articles related to N95 mask decontamination and subsequent testing for the integrity of mask filtration and facial seal. To expand this search, we additionally surveyed the official statements from key health agencies, organizations, and societies for relevant citations. RESULTS: Our initial database search resulted in five articles that met inclusion criteria, with 26 articles added from the expanded search. Our search did not reveal any relevant randomized clinical trials or cohort studies. We found that moist mask heating (65-80°C at 50-85% relative humidity for 20-30 min) and vaporous hydrogen peroxide treatment were supported by the literature to provide consistent viral decontamination without compromising mask seal and filtration efficiency. Other investigated decontamination methods lacked comprehensive scientific evidence for all three of these key criteria. CONCLUSIONS: N95 mask reprocessing using either moist heat or vaporous hydrogen peroxide is recommended to ensure healthcare worker safety.

7.
PLoS One ; 14(5): e0215221, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31120888

RESUMO

Poor reporting quality may contribute to irreproducibility of results and failed 'bench-to-bedside' translation. Consequently, guidelines have been developed to improve the complete and transparent reporting of in vivo preclinical studies. To examine the impact of such guidelines on core methodological and analytical reporting items in the preclinical anesthesiology literature, we sampled a cohort of studies. Preclinical in vivo studies published in Anesthesiology, Anesthesia & Analgesia, Anaesthesia, and the British Journal of Anaesthesia (2008-2009, 2014-2016) were identified. Data was extracted independently and in duplicate. Reporting completeness was assessed using the National Institutes of Health Principles and Guidelines for Reporting Preclinical Research. Risk ratios were used for comparative analyses. Of 7615 screened articles, 604 met our inclusion criteria and included experiments reporting on 52 490 animals. The most common topic of investigation was pain and analgesia (30%), rodents were most frequently used (77%), and studies were most commonly conducted in the United States (36%). Use of preclinical reporting guidelines was listed in 10% of applicable articles. A minority of studies fully reported on replicates (0.3%), randomization (10%), blinding (12%), sample-size estimation (3%), and inclusion/exclusion criteria (5%). Statistics were well reported (81%). Comparative analysis demonstrated few differences in reporting rigor between journals, including those that endorsed reporting guidelines. Principal items of study design were infrequently reported, with few differences between journals. Methods to improve implementation and adherence to community-based reporting guidelines may be necessary to increase transparent and consistent reporting in the preclinical anesthesiology literature.


Assuntos
Avaliação Pré-Clínica de Medicamentos/normas , Relatório de Pesquisa/normas , Analgésicos/uso terapêutico , Animais , Bases de Dados Factuais , Guias como Assunto , Dor/tratamento farmacológico
13.
Am J Physiol Lung Cell Mol Physiol ; 312(5): L710-L721, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28235950

RESUMO

Over past years, a critical role for the immune system and, in particular, for mast cells in the pathogenesis of pulmonary hypertension (PH) has emerged. However, the way in which mast cells promote PH is still poorly understood. Here, we investigated the mechanisms by which mast cells may contribute to PH, specifically focusing on the interaction between the innate and adaptive immune response and the role of B cells and autoimmunity. Experiments were performed in Sprague-Dawley rats and B cell-deficient JH-KO rats in the monocrotaline, Sugen/hypoxia, and the aortic banding model of PH. Hemodynamics, cell infiltration, IL-6 expression, and vascular remodeling were analyzed. Gene array analyses revealed constituents of immunoglobulins as most prominently regulated mast cell-dependent genes in the lung in experimental PH. IL-6 was shown to link mast cells to B cells, as 1) IL-6 was upregulated and colocalized with mast cells and was reduced by mast-cell stabilizers and 2) IL-6 or mast cell blockade reduced B cells in lungs of monocrotaline-treated rats. A functional role for B cells in PH was demonstrated in that either blocking B cells by an anti-CD20 antibody or B-cell deficiency in JH-KO rats attenuated right ventricular systolic pressure and vascular remodeling in experimental PH. We here identify a mast cell-B cell axis driven by IL-6 as a critical immune pathway in the pathophysiology of PH. Our results provide novel insights into the role of the immune system in PH, which may be therapeutically exploited by targeted immunotherapy.


Assuntos
Linfócitos B/metabolismo , Hipertensão Pulmonar/fisiopatologia , Pulmão/irrigação sanguínea , Pulmão/fisiopatologia , Mastócitos/metabolismo , Remodelação Vascular , Animais , Autoanticorpos/metabolismo , Pressão Sanguínea , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Interleucina-6/metabolismo , Masculino , Modelos Biológicos , Análise de Sequência com Séries de Oligonucleotídeos , Ratos Sprague-Dawley , Sístole , Fatores de Tempo
14.
CMAJ Open ; 4(3): E444-E447, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27730108

RESUMO

BACKGROUND: Physicians have traditionally been at the forefront of medical research, bringing clinical questions to the laboratory and returning with ideas for treatment. However, we have anecdotally observed a decline in the popularity of basic science research among trainees. We hypothesized that fewer resident physicians have been pursuing basic science research training over time. METHODS: We examined records from residents in the Surgeon-Scientist and Clinician-Investigator programs at the University of Toronto (1987-2016). Research by residents was categorized independently by 2 raters as basic science, clinical epidemiology or education-related based on the title of the project, the name of the supervisor and Pubmed searches. The study population was divided into quintiles of time, and the proportion pursuing basic science training in each quintile was calculated. RESULTS: Agreement between the raters was 100%; the categorization of the research topic remained unclear in 9 cases. The proportion of trainees pursuing basic science training dropped by 60% from 1987 to 2016 (p = 0.005). INTERPRETATION: Significantly fewer residents in the Surgeon-Scientist and Clinician-Investigator Programs at the University of Toronto are pursuing training in the basic sciences as compared with previous years.

15.
Am J Physiol Lung Cell Mol Physiol ; 310(8): L720-32, 2016 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-26851257

RESUMO

Transcellular albumin transport occurs via caveolae that are abundant in lung microvascular endothelial cells. Stimulation of albumin transcytosis by proinflammatory mediators may contribute to alveolar protein leak in lung injury, yet the regulation of albumin transport and its underlying molecular mechanisms are so far incompletely understood. Here we tested the hypothesis that thrombin may stimulate transcellular albumin transport across lung microvascular endothelial cells in an acid-sphingomyelinase dependent manner. Thrombin increased the transport of fluorescently labeled albumin across confluent human lung microvascular endothelial cell (HMVEC-L) monolayers to an extent that markedly exceeds the rate of passive diffusion. Thrombin activated acid sphingomyelinase (ASM) and increased ceramide production in HMVEC-L, but not in bovine pulmonary artery cells, which showed little albumin transport in response to thrombin. Thrombin increased total caveolin-1 (cav-1) content in both whole cell lysates and lipid rafts from HMVEC-L, and this effect was blocked by inhibition of ASM or de novo protein biosynthesis. Thrombin-induced uptake of albumin into lung microvascular endothelial cells was confirmed in isolated-perfused lungs by real-time fluorescence imaging and electron microscopy of gold-labeled albumin. Inhibition of ASM attenuated thrombin-induced albumin transport both in confluent HMVEC-L and in intact lungs, whereas HMVEC-L treatment with exogenous ASM increased albumin transport and enriched lipid rafts in cav-1. Our findings indicate that thrombin stimulates transcellular albumin transport in an acid sphingomyelinase-dependent manner by inducing de novo synthesis of cav-1 and its recruitment to membrane lipid rafts.


Assuntos
Albuminas/metabolismo , Células Endoteliais/enzimologia , Esfingomielina Fosfodiesterase/metabolismo , Transcitose , Animais , Bovinos , Caveolina 1/metabolismo , Células Cultivadas , Endotélio Vascular/citologia , Ativação Enzimática , Humanos , Pulmão/irrigação sanguínea , Masculino , Microdomínios da Membrana/metabolismo , Microvasos/citologia , Transporte Proteico , Ratos Sprague-Dawley , Trombina/fisiologia
16.
FASEB J ; 30(2): 515-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26467794

RESUMO

Explosive growth in our understanding of genomics and molecular biology have fueled calls for the pursuit of personalized medicine, the notion of harnessing biologic variability to provide patient-specific care. This vision will necessitate a deep understanding of the underlying pathophysiology in each patient. Medical journals play a pivotal role in the education of trainees and clinicians, yet we suspected that the amount of basic science in the top medical journals has been in decline. We conducted an automated search strategy in PubMed to identify basic science articles and calculated the proportion of articles dealing with basic science in the highest impact journals for 8 different medical specialties from 1994 to 2013. We observed a steep decline (40-60%) in such articles over time in almost all of the journals examined. This rapid decline in basic science from medical journals is likely to affect practitioners' understanding of and interest in the basic mechanisms of disease and therapy. In this Life Sciences Forum, we discuss why this decline may be occurring and what it means for the future of science and medicine.


Assuntos
Pesquisa Biomédica/estatística & dados numéricos , Publicações Periódicas como Assunto , Editoração , Fatores de Tempo
17.
Am J Physiol Lung Cell Mol Physiol ; 309(9): L924-41, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26502478

RESUMO

Pulmonary hypertension (PH) is characterized by elevated pulmonary arterial pressure leading to right-sided heart failure and can arise from a wide range of etiologies. The most common cause of PH, termed Group 2 PH, is left-sided heart failure and is commonly known as pulmonary hypertension with left heart disease (PH-LHD). Importantly, while sharing many clinical features with pulmonary arterial hypertension (PAH), PH-LHD differs significantly at the cellular and physiological levels. These fundamental pathophysiological differences largely account for the poor response to PAH therapies experienced by PH-LHD patients. The relatively high prevalence of this disease, coupled with its unique features compared with PAH, signal the importance of an in-depth understanding of the mechanistic details of PH-LHD. The present review will focus on the current state of knowledge regarding the pathomechanisms of PH-LHD, highlighting work carried out both in human trials and in preclinical animal models. Adaptive processes at the alveolocapillary barrier and in the pulmonary circulation, including alterations in alveolar fluid transport, endothelial junctional integrity, and vasoactive mediator secretion will be discussed in detail, highlighting the aspects that impact the response to, and development of, novel therapeutics.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Hipertensão Pulmonar/fisiopatologia , Alvéolos Pulmonares/fisiopatologia , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/patologia , Humanos , Hipertensão Pulmonar/complicações , Hipertensão Pulmonar/epidemiologia , Hipertensão Pulmonar/patologia , Prevalência , Alvéolos Pulmonares/irrigação sanguínea , Alvéolos Pulmonares/patologia
19.
Compr Physiol ; 5(2): 531-59, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25880504

RESUMO

The pulmonary endothelium represents a heterogeneous cell monolayer covering the luminal surface of the entire lung vasculature. As such, this cell layer lies at a critical interface between the blood, airways, and lung parenchyma, and must act as a selective barrier between these diverse compartments. Lung endothelial cells are able to produce and secrete mediators, display surface receptor, and cellular adhesion molecules, and metabolize circulating hormones to influence vasomotor tone, both local and systemic inflammation, and coagulation functions. In this review, we will explore the role of the pulmonary endothelium in each of these systems, highlighting key regulatory functions of the pulmonary endothelial cell, as well as novel aspects of the pulmonary endothelium in contrast to the systemic cell type. The interactions between pulmonary endothelial cells and both leukocytes and platelets will be discussed in detail, and wherever possible, elements of endothelial control over physiological and pathophysiological processes will be examined.


Assuntos
Coagulação Sanguínea/fisiologia , Células Endoteliais/fisiologia , Pneumonia/fisiopatologia , Artéria Pulmonar/fisiologia , Circulação Pulmonar/fisiologia , Sistema Vasomotor/fisiologia , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Humanos , Modelos Cardiovasculares , Artéria Pulmonar/citologia
20.
Proc Natl Acad Sci U S A ; 112(13): E1614-23, 2015 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-25829545

RESUMO

Hypoxic pulmonary vasoconstriction (HPV) optimizes pulmonary ventilation-perfusion matching in regional hypoxia, but promotes pulmonary hypertension in global hypoxia. Ventilation-perfusion mismatch is a major cause of hypoxemia in cystic fibrosis. We hypothesized that cystic fibrosis transmembrane conductance regulator (CFTR) may be critical in HPV, potentially by modulating the response to sphingolipids as mediators of HPV. HPV and ventilation-perfusion mismatch were analyzed in isolated mouse lungs or in vivo. Ca(2+) mobilization and transient receptor potential canonical 6 (TRPC6) translocation were studied in human pulmonary (PASMCs) or coronary (CASMCs) artery smooth muscle cells. CFTR inhibition or deficiency diminished HPV and aggravated ventilation-perfusion mismatch. In PASMCs, hypoxia caused CFTR to interact with TRPC6, whereas CFTR inhibition attenuated hypoxia-induced TRPC6 translocation to caveolae and Ca(2+) mobilization. Ca(2+) mobilization by sphingosine-1-phosphate (S1P) was also attenuated by CFTR inhibition in PASMCs, but amplified in CASMCs. Inhibition of neutral sphingomyelinase (nSMase) blocked HPV, whereas exogenous nSMase caused TRPC6 translocation and vasoconstriction that were blocked by CFTR inhibition. nSMase- and hypoxia-induced vasoconstriction, yet not TRPC6 translocation, were blocked by inhibition or deficiency of sphingosine kinase 1 (SphK1) or antagonism of S1P receptors 2 and 4 (S1P2/4). S1P and nSMase had synergistic effects on pulmonary vasoconstriction that involved TRPC6, phospholipase C, and rho kinase. Our findings demonstrate a central role of CFTR and sphingolipids in HPV. Upon hypoxia, nSMase triggers TRPC6 translocation, which requires its interaction with CFTR. Concomitant SphK1-dependent formation of S1P and activation of S1P2/4 result in phospholipase C-mediated TRPC6 and rho kinase activation, which conjointly trigger vasoconstriction.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Hipertensão Pulmonar/metabolismo , Pulmão/patologia , Vasoconstrição , Animais , Cálcio/metabolismo , Sinalização do Cálcio , Ceramidas/química , Vasos Coronários/metabolismo , Humanos , Hipóxia/patologia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CFTR , Miócitos de Músculo Liso/metabolismo , Oxigênio/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Transporte Proteico , Artéria Pulmonar/metabolismo , Receptores de Lisoesfingolipídeo/metabolismo , Transdução de Sinais , Esfingomielina Fosfodiesterase/metabolismo , Canais de Cátion TRPC/metabolismo , Canal de Cátion TRPC6 , Fosfolipases Tipo C/metabolismo , Quinases Associadas a rho/metabolismo
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