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1.
JMIR Diabetes ; 8: e42564, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37121571

RESUMO

BACKGROUND: Youth (aged 14-24 years) living with type 1 diabetes (T1D) encounter increased challenges in their diabetes self-management (DSM), especially during the transition to adult care. Although DSM education and support are imperative, there is insufficient information on how web-based digital tools tailored to their demands can be developed. OBJECTIVE: On the basis of the Behavior Change Wheel, this study aims to identify, among youth living with T1D, the needs and factors influencing their DSM in the context of health care transition and to inform the adaptation (content and features) of an adult self-guided web application (Support). METHODS: Internet-based semistructured individual interviews based on a phenomenological study design were conducted with 21 youths, and transcripts were analyzed using an inductive approach with concept mapping. RESULTS: Factors influencing T1D self-management were categorized into barriers and facilitators and then as external or internal. Features influencing the accessibility to information, increasing the sense of support, and use of the tool were positively accepted. Features unrelated to their expectations of digital tool use or difficulty navigating were viewed negatively. Participants expressed an interest in reliable, practical, and novel educational content. Although youth considered the information provided by medical professionals to be important, peer exchange was deemed necessary to obtain a practical perspective and real-life examples. CONCLUSIONS: Compared with the adult population, in addition to tailored content and a simplified information search process, when building a DSM education and support digital tool for youth, features should be selected to encourage supervised peer exchange.

2.
Nature ; 605(7911): 669-674, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35614249

RESUMO

Quantum computers hold the promise of solving computational problems that are intractable using conventional methods1. For fault-tolerant operation, quantum computers must correct errors occurring owing to unavoidable decoherence and limited control accuracy2. Here we demonstrate quantum error correction using the surface code, which is known for its exceptionally high tolerance to errors3-6. Using 17 physical qubits in a superconducting circuit, we encode quantum information in a distance-three logical qubit, building on recent distance-two error-detection experiments7-9. In an error-correction cycle taking only 1.1 µs, we demonstrate the preservation of four cardinal states of the logical qubit. Repeatedly executing the cycle, we measure and decode both bit-flip and phase-flip error syndromes using a minimum-weight perfect-matching algorithm in an error-model-free approach and apply corrections in post-processing. We find a low logical error probability of 3% per cycle when rejecting experimental runs in which leakage is detected. The measured characteristics of our device agree well with a numerical model. Our demonstration of repeated, fast and high-performance quantum error-correction cycles, together with recent advances in ion traps10, support our understanding that fault-tolerant quantum computation will be practically realizable.

3.
Sci Rep ; 11(1): 24009, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34907268

RESUMO

Traumatic brain injury (TBI) leads to a deleterious neuroinflammation, originating from microglial activation. Monitoring microglial activation is an indispensable step to develop therapeutic strategies for TBI. In this study, we evaluated the use of the 18-kDa translocator protein (TSPO) in positron emission tomography (PET) and cellular analysis to monitor microglial activation in a mild TBI mouse model. TBI was induced on male Swiss mice. PET imaging analysis with [18F]FEPPA, a TSPO radiotracer, was performed at 1, 3 and 7 days post-TBI and flow cytometry analysis on brain at 1 and 3 days post-TBI. PET analysis showed no difference in TSPO expression between non-operated, sham-operated and TBI mice. Flow cytometry analysis demonstrated an increase in TSPO expression in ipsilateral brain 3 days post-TBI, especially in microglia, macrophages, lymphocytes and neutrophils. Moreover, microglia represent only 58.3% of TSPO+ cells in the brain. Our results raise the question of the use of TSPO radiotracer to monitor microglial activation after TBI. More broadly, flow cytometry results point the lack of specificity of TSPO for microglia and imply that microglia contribute to the overall increase in TSPO in the brain after TBI, but is not its only contributor.


Assuntos
Anilidas/farmacologia , Leucócitos/metabolismo , Microglia/metabolismo , Tomografia por Emissão de Pósitrons , Piridinas/farmacologia , Receptores de GABA , Animais , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Lesões Encefálicas Traumáticas/metabolismo , Masculino , Camundongos
4.
Neuroscience ; 466: 205-221, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33895341

RESUMO

Insulin-like growth factors (IGF) are potent neurotrophic and neurorepair factors that were recently proposed as biomarkers of traumatic brain injury (TBI) and associated psychiatric comorbidities, in particular post-traumatic stress disorder (PSTD). We tested the hypothesis that the IGF system is differentially deregulated in the acute and early chronic stages of TBI, and under acute stress. Plasma and brain IGF1 and IGF2 levels were evaluated in mice 3 weeks and 3 days after a controlled cortical impact (CCI)-induced mild-to-moderate TBI. The effects of conditioned fear on IGF levels and its interaction with TBI (TBI followed, 3 weeks later, by fear-inducing procedures) were also evaluated. In the plasma, IGF1 decreased 3 weeks post-TBI only (-9%), whereas IGF2 remained unaffected. In the brain, IGF1 increased only in the cortex and hippocampus at 3 weeks post-TBI (up to +650%). At 3 days, surpringly, this increase was more diffuse and more important in sham (craniotomized) animals. Additionally, IGF2 immunostaining in brain ventricles was reorganized in TBI animals at both post-TBI stages. Conditioned fear exposure did not influence the effects of early chronic TBI on plasma IGF1 levels, but reduced plasma IGF2 (-6%) levels. It also dampened the effects of TBI on brain IGF systems, but brain IGF1 level and IGF2 tissue distribution remained statistically different from controls under these conditions. In co-exposed animals, DNA methylation increased at the hippocampal Igf1 gene promoter. These results show that blood IGF1 and IGF2 are most reduced in the early chronic phase of TBI and after exposure to a stressful event, and that the brain IGF system is up-regulated after TBI, and more so in the acute phase.


Assuntos
Lesões Encefálicas Traumáticas , Animais , Biomarcadores , Encéfalo/metabolismo , Medo , Hipocampo/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Camundongos
5.
Fundam Clin Pharmacol ; 35(3): 524-538, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33527472

RESUMO

Traumatic brain injury (TBI) constitutes a major health problem worldwide and is a leading cause of death and disability in individuals, contributing to devastating socioeconomic consequences. Despite numerous promising pharmacological strategies reported as neuroprotective in preclinical studies, the translation to clinical trials always failed, albeit the great diversity of therapeutic targets evaluated. In this review, first, we described epidemiologic features, causes, and primary and secondary injuries of TBI. Second, we outlined the current literature on animal models of TBI, and we described their goals, their advantages and disadvantages according to the species used, the type of injury induced, and their clinical relevance. Third, we defined the concept of neuroprotection and discussed its evolution. We also identified the reasons that might explain the failure of clinical translation. Then, we reviewed post-TBI neuroprotective treatments with a focus on the following pleiotropic drugs, considered "low hanging fruit" with high probability of success: glitazones, glibenclamide, statins, erythropoietin, and progesterone, that were largely tested and demonstrated efficient in preclinical models of TBI. Finally, our review stresses the need to establish a close cooperation between basic researchers and clinicians to ensure the best clinical translation for neuroprotective strategies for TBI.


Assuntos
Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/fisiopatologia , Neuroproteção/fisiologia , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Fatores Etários , Animais , Ensaios Clínicos como Assunto , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos
6.
J Neurotrauma ; 37(11): 1342-1357, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31830858

RESUMO

Traumatic brain injury (TBI) is a chronic pathology, inducing long-term deficits that remain understudied in pre-clinical studies. In this context, exploration, anxiety-like behavior, cognitive flexibility, and motor coordination were assessed until 5 and 10 months after an experimental TBI in the adult mouse, using two cohorts. In order to differentiate age, surgery, and remote gray and white matter lesions, three groups (unoperated, sham-operated, and TBI) were studied. TBI induced delayed motor coordination deficits at the pole test, 4.5 months after injury, that could be explained by gray and white matter damages in ipsilateral nigrostriatal structures (striatum, internal capsule) that were spreading to new structures between cohorts, at 5 versus 10 months after the injury. Further, TBI induced an enhanced exploratory behavior during stressful situations (active phase during actimetry test, object exploration in an open field), risk-taking behaviors in the elevated plus maze 5 months after injury, and a cognitive inflexibility in the Barnes maze that persisted until 9 months after the injury. These behavioral modifications could be related to the white and gray matter lesions observed in ipsi- and contralateral limbic structures (amygdala, hilus/cornu ammonis 4, hypothalamus, external capsule, corpus callosum, and cingular cortex) that were spreading to new structures between cohorts, at 5 months versus 10 months after the injury. The present study corroborates clinical findings on TBI and provides a relevant rodent chronic model which could help in validating pharmacological strategies against the chronic consequences of TBI.


Assuntos
Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/psicologia , Encéfalo/patologia , Comportamento Exploratório/fisiologia , Aprendizagem em Labirinto/fisiologia , Animais , Lesões Encefálicas Traumáticas/cirurgia , Seguimentos , Masculino , Camundongos , Fatores de Tempo
7.
Behav Brain Res ; 360: 69-80, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30500429

RESUMO

Efforts are still needed regarding the research of therapeutics for ischemic stroke. While in experimental studies the protective effect of pharmacological agents is often highlighted by a reduction of the lesion size evaluated in the short term (days), in clinical studies a functional recovery of patients suffering from stroke is expected on the long-term (months and years). Long-term functional preclinical studies are highly recommended to evaluate potential neuroprotective agents for stroke, rather than an assessment of the infarction size at a short time point. The present study thus aimed to select among various behavioral tests those able to highlight long-term deficits (3 months) after cerebral ischemia in mice. Permanent focal cerebral ischemia was carried out in male Swiss mice by intraluminal occlusion of the left middle cerebral artery (MCA). Fourteen behavioral tests were assessed from 7 days to 90 days after ischemia (locomotor activity, neurological score, exit circle test, grip and string tests, chimney test, adhesive removal test, pole test, beam-walking tests, elevated plus maze, marble burying test, forced swimming test, novel object recognition test). The present study clearly identified a battery of behavioral tests able to highlight deficits up to 3 months in our mouse model of permanent MCA occlusion (locomotor activity, neurological score, adhesive removal test, pole test, beam-walking tests, elevated plus maze, marble burying test, forced swimming test and novel object recognition test). This battery of behavioral tests highlighting long-term deficits is useful to study future neuroprotective strategies for stroke treatment.


Assuntos
Isquemia Encefálica/complicações , Transtornos Mentais/diagnóstico , Transtornos Mentais/etiologia , Animais , Isquemia Encefálica/tratamento farmacológico , Modelos Animais de Doenças , Comportamento Exploratório/fisiologia , Locomoção/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Exame Neurológico , Oxigênio/uso terapêutico , Desempenho Psicomotor , Estatísticas não Paramétricas , Natação
8.
Brain Behav Immun ; 73: 375-389, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29852289

RESUMO

Neonatal acute ischemic stroke is a cause of neonatal brain injury that occurs more frequently in males, resulting in associated neurobehavioral disorders. The bases for these sex differences are poorly understood but might include the number, morphology and activation of microglia in the developing brain when subjected to stroke. Interestingly, poly (ADP-ribose) polymerase (PARP) inhibition preferentially protects males against neonatal ischemia. This study aims to examine the effects of PJ34, a PARP inhibitor, on microglial phenotypes at 3 and 8 days and on neurobehavioral disorders in adulthood for both male and female P9 mice subjected to permanent middle cerebral artery occlusion (pMCAo). PJ34 significantly reduced the lesion size by 78% and reduced the density of CX3CR1gfp-labeled microglial cells by 46% when examined 3 days after pMCAo in male but not in female mice. Eight days after pMCAo, the number of Iba1+/Cox-2+ cells did not differ between male and female mice in the cortical peri-infarct region. In the amygdala, Iba1+/Cox-2+ (M1-like) cell numbers were significantly decreased in PJ34-treated males but not in females. Conversely, Iba1+/Arg-1+ (M2-like) and Arg-1+/Cox-2+ (Mtransitional) cell numbers were significantly increased in PJ34-treated females. Regarding neurobehavioral disorders during adulthood, pMCAo induced a motor coordination deficit and a spatial learning deficit in female mice only. PJ34 prevented MBP fibers, motor coordination and learning disorders during adulthood in female mice. Our data show significant sex differences in the effects of PARP inhibition on microglia phenotypes following neonatal ischemia, associated with improved behavior and myelination during adulthood in females only. Our findings suggest that modulating microglial phenotypes may play key roles in behavior disorders and white matter injury following neonatal stroke.


Assuntos
Isquemia Encefálica/patologia , Microglia/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/metabolismo , Animais , Animais Recém-Nascidos , Lesões Encefálicas/complicações , Isquemia Encefálica/metabolismo , Modelos Animais de Doenças , Feminino , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fenantrenos/metabolismo , Fenantrenos/farmacologia , Fenótipo , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/metabolismo , Fatores Sexuais , Acidente Vascular Cerebral/patologia
9.
Am J Clin Nutr ; 108(1): 62-76, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29917037

RESUMO

Background: To optimize the prevention of type 2 diabetes (T2D), high-risk obese subjects with the best metabolic recovery after a hypocaloric diet should be targeted. Apolipoprotein B lipoproteins (apoB lipoproteins) induce white adipose tissue (WAT) dysfunction, which in turn promotes postprandial hypertriglyceridemia, insulin resistance (IR), and hyperinsulinemia. Objective: The aim of this study was to explore whether high plasma apoB, or number of plasma apoB lipoproteins, identifies subjects who best ameliorate WAT dysfunction and related risk factors after a hypocaloric diet. Design: Fifty-nine men and postmenopausal women [mean ± SD age: 58 ± 6 y; body mass index (kg/m2): 32.6 ± 4.6] completed a prospective study with a 6-mo hypocaloric diet (-500 kcal/d). Glucose-induced insulin secretion (GIIS) and insulin sensitivity (IS) were measured by 1-h intravenous glucose-tolerance test (IVGTT) followed by a 3-h hyperinsulinemic-euglycemic clamp, respectively. Ex vivo gynoid WAT function (i.e., hydrolysis and storage of 3H-triolein-labeled triglyceride-rich lipoproteins) and 6-h postprandial plasma clearance of a 13C-triolein-labeled high-fat meal were measured in a subsample (n = 25). Results: Postintervention first-phase GIISIVGTT and total C-peptide secretion decreased in both sexes, whereas second-phase and total GIISIVGTT and clamp IS were ameliorated in men (P < 0.05). Baseline plasma apoB was associated with a postintervention increase in WAT function (r = 0.61) and IS (glucose infusion rate divided by steady state insulin (M/Iclamp) r = 0.30) and a decrease in first-phase, second-phase, and total GIISIVGTT (r = -0.30 to -0.35) without sex differences. The association with postintervention amelioration in WAT function and GIISIVGTT was independent of plasma cholesterol (total, LDL, and HDL), sex, and changes in body composition. Subjects with high baseline plasma apoB (1.2 ± 0.2 g/L) showed a significant increase in WAT function (+105%; P = 0.012) and a decrease in total GIISIVGTT (-34%; P ≤ 0.001), whereas sex-matched subjects with low plasma apoB (0.7 ± 0.1 g/L) did not, despite equivalent changes in body composition and energy intake and expenditure. Conclusions: High plasma apoB identifies obese subjects who best ameliorate WAT dysfunction and glucose-induced hyperinsulinemia, independent of changes in adiposity after consumption of a hypocaloric diet. We propose that subjects with high plasma apoB represent an optimal target group for the primary prevention of T2D by hypocaloric diets. This trial was registered at BioMed Central as ISRCTN14476404.


Assuntos
Tecido Adiposo Branco/metabolismo , Apolipoproteínas B/sangue , Ingestão de Energia/fisiologia , Glucose/farmacologia , Hiperinsulinismo/sangue , Obesidade/metabolismo , Feminino , Humanos , Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Período Pós-Prandial , Fatores de Risco
10.
Nucleic Acids Res ; 46(9): 4622-4631, 2018 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-29684182

RESUMO

We directly visualize the topology-mediated interactions between an unwinding site on a supercoiled DNA plasmid and a specific probe molecule designed to bind to this site, as a function of DNA supercoiling and temperature. The visualization relies on containing the DNA molecules within an enclosed array of glass nanopits using the Convex Lens-induced Confinement (CLiC) imaging method. This method traps molecules within the focal plane while excluding signal from out-of-focus probes. Simultaneously, the molecules can freely diffuse within the nanopits, allowing for accurate measurements of exchange rates, unlike other methods which could introduce an artifactual bias in measurements of binding kinetics. We demonstrate that the plasmid's structure influences the binding of the fluorescent probes to the unwinding site through the presence, or lack, of other secondary structures. With this method, we observe an increase in the binding rate of the fluorescent probe to the unwinding site with increasing temperature and negative supercoiling. This increase in binding is consistent with the results of our numerical simulations of the probability of site-unwinding. The temperature dependence of the binding rate has allowed us to distinguish the effects of competing higher order DNA structures, such as Z-DNA, in modulating local site-unwinding, and therefore binding.


Assuntos
DNA Super-Helicoidal/química , DNA Topoisomerases Tipo I/metabolismo , Cinética , Microscopia de Fluorescência , Sondas de Oligonucleotídeos/química , Plasmídeos/genética , Temperatura
11.
Mol Neurobiol ; 55(12): 9156-9168, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29651748

RESUMO

Benefits from thrombolysis with recombinant tissue plasminogen activator (rt-PA) after ischemic stroke remain limited due to a narrow therapeutic window, low reperfusion rates, and increased risk of hemorrhagic transformations (HT). Experimental data showed that rt-PA enhances the post-ischemic activation of poly(ADP-ribose)polymerase (PARP) which in turn contributes to blood-brain barrier injury. The aim of the present study was to evaluate whether PJ34, a potent PARP inhibitor, improves poor reperfusion induced by delayed rt-PA administration, exerts vasculoprotective effects, and finally increases the therapeutic window of rt-PA. Stroke was induced by thrombin injection (0.75 UI in 1 µl) in the left middle cerebral artery (MCA) of male Swiss mice. Administration of rt-PA (0.9 mg kg-1) or saline was delayed for 4 h after ischemia onset. Saline or PJ34 (3 mg kg-1) was given intraperitoneally twice, just after thrombin injection and 3 h later, or once, 3 h after ischemia onset. Reperfusion was evaluated by laser Doppler, vascular inflammation by immunohistochemistry of vascular cell adhesion molecule-1 (VCAM-1) expression, and vasospasm by morphometric measurement of the MCA. Edema, cortical lesion, and sensorimotor deficit were evaluated. Treatment with PJ34 improved rt-PA-induced reperfusion and promoted vascular protection including reduction in vascular inflammation (decrease in VCAM-1 expression), HT, and MCA vasospasm. Additionally, the combined treatment significantly reduced brain edema, cortical lesion, and sensorimotor deficit. In conclusion, the combination of the PARP inhibitor PJ34 with rt-PA after cerebral ischemia may be of particular interest in order to improve thrombolysis with an extended therapeutic window.


Assuntos
Fármacos Neuroprotetores/uso terapêutico , Fenantrenos/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Reperfusão , Acidente Vascular Cerebral/tratamento farmacológico , Trombose/tratamento farmacológico , Animais , Edema/complicações , Edema/tratamento farmacológico , Edema/patologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Hemorragia/complicações , Hemorragia/tratamento farmacológico , Hemorragia/patologia , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/patologia , Inflamação/patologia , Masculino , Camundongos , Fármacos Neuroprotetores/farmacologia , Fenantrenos/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Proteólise/efeitos dos fármacos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/patologia , Trombose/complicações , Trombose/patologia , Ativador de Plasminogênio Tecidual/administração & dosagem , Ativador de Plasminogênio Tecidual/farmacologia , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do Tratamento , Vasoespasmo Intracraniano/complicações , Vasoespasmo Intracraniano/tratamento farmacológico , Vasoespasmo Intracraniano/patologia
12.
PLoS One ; 12(9): e0184811, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28910378

RESUMO

Traumatic brain injury (TBI) results in white matter injury (WMI) that is associated with neurological deficits. Neuroinflammation originating from microglial activation may participate in WMI and associated disorders. To date, there is little information on the time courses of these events after mild TBI. Therefore we investigated (i) neuroinflammation, (ii) WMI and (iii) behavioral disorders between 6 hours and 3 months after mild TBI. For that purpose, we used experimental mild TBI in mice induced by a controlled cortical impact. (i) For neuroinflammation, IL-1b protein as well as microglial phenotypes, by gene expression for 12 microglial activation markers on isolated CD11b+ cells from brains, were studied after TBI. IL-1b protein was increased at 6 hours and 1 day. TBI induced a mixed population of microglial phenotypes with both pro-inflammatory, anti-inflammatory and immunomodulatory markers from 6 hours to 3 days post-injury. At 7 days, microglial activation was completely resolved. (ii) Three myelin proteins were assessed after TBI on ipsi- and contralateral corpus callosum, as this structure is enriched in white matter. TBI led to an increase in 2',3'-cyclic-nucleotide 3'-phosphodiesterase, a marker of immature and mature oligodendrocyte, at 2 days post-injury; a bilateral demyelination, evaluated by myelin basic protein, from 7 days to 3 months post-injury; and an increase in myelin oligodendrocyte glycoprotein at 6 hours and 3 days post-injury. Transmission electron microscopy study revealed various myelin sheath abnormalities within the corpus callosum at 3 months post-TBI. (iii) TBI led to sensorimotor deficits at 3 days post-TBI, and late cognitive flexibility disorder evidenced by the reversal learning task of the Barnes maze 3 months after injury. These data give an overall invaluable overview of time course of neuroinflammation that could be involved in demyelination and late cognitive disorder over a time-scale of 3 months in a model of mild TBI. This model could help to validate a pharmacological strategy to prevent post-traumatic WMI and behavioral disorders following mild TBI.


Assuntos
Concussão Encefálica/imunologia , Transtornos Cognitivos/etiologia , Microglia/imunologia , Bainha de Mielina/patologia , Substância Branca/patologia , Animais , Biomarcadores/metabolismo , Concussão Encefálica/complicações , Concussão Encefálica/metabolismo , Modelos Animais de Doenças , Interleucina-1beta/metabolismo , Aprendizagem em Labirinto , Camundongos , Microscopia Eletrônica de Transmissão , Bainha de Mielina/metabolismo
13.
J Neurol Sci ; 370: 187-195, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27772757

RESUMO

Thrombolysis with recombinant tissue plasminogen activator (rt-PA) is currently the only approved pharmacological strategy for acute ischemic stroke. However, rt-PA exhibits vascular toxicity mainly due to endothelial damage. To investigate the mechanisms underlying rt-PA-induced endothelial alterations, we assessed the role of rt-PA in the generation of endothelial microparticles (EMPs), emerging biological markers and effectors of endothelial dysfunction. The mouse brain-derived endothelial cell line bEnd.3 was used. Cells were treated with rt-PA at 20, 40 or 80µg/ml for 15 or 24h, and EMPs were quantified in the culture media using Annexin-V staining coupled with flow cytometry. Rt-PA enhanced EMP release from bEnd.3 cells with a maximal increase at the 40µg/ml dose for 24h (+78% compared to controls). Using tranexamic acid and aprotinin we demonstrated that plasmin is responsible for rt-PA-induced EMP release. The p38 MAPK inhibitor SB203580 and the poly(ADP-ribose)polymerase (PARP) inhibitor PJ34 also reduced rt-PA-induced EMP production, suggesting that p38 MAPK and PARP are downstream intracellular effectors of rt-PA/plasmin. Rt-PA also altered through plasmin the morphology and the confluence of bEnd.3 cells. By contrast, these changes did not implicate p38 MAPK and PARP. This study demonstrates that rt-PA induces the production of microparticles by cerebral endothelial cells, through plasmin, p38 MAPK and PARP pathways. Determining the phenotype of these EMPs to clarify their role on the endothelium in ischemic conditions could thus be of particular interest.


Assuntos
Micropartículas Derivadas de Células/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Fibrinolisina/metabolismo , Fibrinolíticos/farmacologia , Ativador de Plasminogênio Tecidual/farmacologia , Animais , Encéfalo/irrigação sanguínea , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Micropartículas Derivadas de Células/metabolismo , Relação Dose-Resposta a Droga , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Camundongos , Plasminogênio/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
14.
Can J Diabetes ; 40(5): 389-392, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27397678

RESUMO

OBJECTIVES: To determine the modifiable factors affecting glucose variability in people with cystic fibrosis (CF). CF-related diabetes (CFRD) is the most common complication of CF, and its presence increases morbidity and mortality in patients. Patients with CF (with and without CFRD) have potentially harmful glucose fluctuations and glucose excursions when compared to healthy adults. Carbohydrate intake and exercise have been shown to affect glycemia. Therefore, our hypothesis was that the proportion of energy from carbohydrates and total energy expenditure (TEE) would influence glucose fluctuations in adults with CF. METHODS: A cross-sectional study involved 36 patients with CF, in whom continuous glucose monitoring systems were installed. Glucose fluctuations were then quantified using 3 indexes: mean amplitude of glucose excursions, standard deviation and coefficient of variation. Patients filled out a 3-day food diary to quantify energy intake and the proportions of calories from carbohydrates, fats and proteins, and they wore Sensewear Armbands to estimate spontaneous TEE and footsteps walked. Glucose tolerance status was determined using oral glucose tolerance tests. RESULTS: Patients with CF with normal and impaired glucose tolerance had fewer glucose fluctuations than patients with CFRD (p<0.05). However, linear regression models used to determine whether nutrition or energy expenditure affects glucose fluctuations demonstrated that energy, the proportion of carbohydrates, of fat and of protein, TEE or the number of footsteps walked did not affect glucose fluctuation indexes (p>0.05). CONCLUSIONS: TEE and the proportion of energy from carbohydrates did not affect glucose fluctuations in adults with CF.


Assuntos
Glicemia , Fibrose Cística/metabolismo , Metabolismo Energético , Adulto , Metabolismo dos Carboidratos , Estudos Transversais , Fibrose Cística/complicações , Diabetes Mellitus/etiologia , Ingestão de Energia , Humanos , Estado Nutricional
15.
Can J Diabetes ; 40(4): 318-23, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27373433

RESUMO

OBJECTIVES: 1) To characterize the nutritional treatment of hypoglycemia in adult patients with type 1 diabetes mellitus and 2) to compare the characteristics of participants who follow the recommendations with the characteristics of those who do not. METHODS: A total of 121 adults with type 1 diabetes were included in this cross-sectional analysis. Participants completed a food record and a glycemia and insulin doses logbook to collect data on mild to moderate hypoglycemic events (glycemia <4.0 mmol/L or 4.0 to 5.0 mmol/L with symptoms) and their treatments over a 2-day period. Participants were identified as overcorrecting if they consumed, within 15 minutes after the episode, >20g of carbohydrates for correction. Self-administered questionnaires about fear of hypoglycemia were completed, and cardiometabolic profile variables were measured (glycated hemoglobin, blood pressure, lipid profile and body mass indexes). RESULTS: Of the 121 participants, 94 (78%) reported at least 1 hypoglycemic event, for a total of 271 events (2.2±2.1 episodes per patient). Of these events, 64% were treated within 15 minutes, and they were treated primarily with fruit juice or sweet beverages (39%) or mixed snacks (29%). Average carbohydrate intake for treatment was 32±24 grams. Of the participants, 73% overtreated their episodes. They were significantly younger and had greater fear of hypoglycemia than those who treated the episodes adequately. No difference was observed for cardiometabolic variables. CONCLUSIONS: The majority of patients in our cohort overtreated their hypoglycemic episodes. These results suggest that hypoglycemia-correction education needs to be reinforced.


Assuntos
Diabetes Mellitus Tipo 1/complicações , Hipoglicemia/dietoterapia , Adulto , Fatores Etários , Estudos de Coortes , Estudos Transversais , Diabetes Mellitus Tipo 1/tratamento farmacológico , Feminino , Humanos , Hipoglicemia/complicações , Hipoglicemia/psicologia , Insulina/uso terapêutico , Masculino
16.
J Acad Nutr Diet ; 115(12): 1965-74, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26052042

RESUMO

BACKGROUND: The Mediterranean-style dietary pattern has been associated with several cardiometabolic benefits, yet no study has assessed the potential benefits of this diet in adults with type 1 diabetes mellitus (T1DM). OBJECTIVE: The objective of the present study was to examine the association between cardiometabolic profile and alignment of the diet with 1) Canadian nutrient recommendations for T1DM in terms of fat, protein, carbohydrate, saturated fat, dietary fiber, and sodium and 2) a Mediterranean-style dietary pattern among adults with T1DM. DESIGN/PARTICIPANTS/SETTING: This is a cross-sectional analysis including 118 adults with T1DM recruited between 2011 and 2013 in Montreal, Canada. STATISTICAL ANALYSES: Body mass index (calculated as kg/m(2)), waist circumference, truncal fat percentage (dual-energy x-ray absorptiometry), blood pressure, and lipid profile values were measured. Insulin sensitivity was estimated (estimated glucose disposal rate). A 3-day food record was completed and physical activity was measured with a motion sensor. Differences for the cardiometabolic profile between groups with a diet meeting the Canadian nutrient recommendations for T1DM (percentage of energy from fat, protein, carbohydrate, saturated fat, as well as grams of dietary fiber and milligrams of sodium) or not were examined with general linear models. A Mediterranean diet score was calculated (range=0 to 44) and Pearson correlations between this score and cardiometabolic variables were computed. Significance was set at P≤0.05. RESULTS: Participants' mean ± standard deviation age was 44.3±12.3 years, glycated hemoglobin was 8.0%±1.1%, and Mediterranean diet score was 20.2±5.0. Having a diet that meets at least three nutritional recommendations was associated with a lower truncal fat percentage (28.0% vs 32.2%; P=0.01) only. In contrast, the Mediterranean diet score was inversely correlated with body mass index (r=-0.30, P=0.002), waist circumference (r=-0.31, P=0.002), truncal fat percentage (r=-0.38, P<0.001), systolic (r=-0.20, P=0.03) and diastolic blood pressure (r=-0.23, P=0.01), and was directly correlated with estimated glucose disposal rate (r=0.22, P=0.03), after adjustments for energy intake, sex, and age. The association with estimated glucose disposal rate was no longer significant (P=0.055) after adjustment for physical activity level. CONCLUSIONS: These results suggest that a higher Mediterranean diet score in the context of T1DM is associated with a favorable cardiometabolic profile. Further research is needed to confirm these findings.


Assuntos
Sistema Cardiovascular , Diabetes Mellitus Tipo 1/fisiopatologia , Dieta Mediterrânea , Dieta , Metaboloma/fisiologia , Adulto , Pressão Sanguínea , Composição Corporal , Índice de Massa Corporal , Canadá , Estudos Transversais , Carboidratos da Dieta , Gorduras na Dieta , Fibras na Dieta , Proteínas Alimentares , Ingestão de Energia , Feminino , Hemoglobinas Glicadas/análise , Humanos , Resistência à Insulina , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Política Nutricional , Circunferência da Cintura
17.
Lancet Diabetes Endocrinol ; 3(1): 17-26, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25434967

RESUMO

BACKGROUND: The artificial pancreas is an emerging technology for the treatment of type 1 diabetes and two configurations have been proposed: single-hormone (insulin alone) and dual-hormone (insulin and glucagon). We aimed to delineate the usefulness of glucagon in the artificial pancreas system. METHODS: We did a randomised crossover trial of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy (continuous subcutaneous insulin infusion) in participants aged 12 years or older with type 1 diabetes. Participants were assigned in a 1:1:1:1:1:1 ratio with blocked randomisation to the three interventions and attended a research facility for three 24-h study visits. During visits when the patient used the single-hormone artificial pancreas, insulin was delivered based on glucose sensor readings and a predictive dosing algorithm. During dual-hormone artificial pancreas visits, glucagon was also delivered during low or falling glucose. During conventional insulin pump therapy visits, patients received continuous subcutaneous insulin infusion. The study was not masked. The primary outcome was the time for which plasma glucose concentrations were in the target range (4·0-10·0 mmol/L for 2 h postprandially and 4·0-8·0 mmol/L otherwise). Hypoglycaemic events were defined as plasma glucose concentration of less than 3·3 mmol/L with symptoms or less than 3·0 mmol/L irrespective of symptoms. Analysis was by modified intention to treat, in which we included data for all patients who completed at least two visits. A p value of less than 0·0167 (0·05/3) was regarded as significant. This trial is registered with ClinicalTrials.gov, number NCT01754337. FINDINGS: The mean proportion of time spent in the plasma glucose target range over 24 h was 62% (SD 18), 63% (18), and 51% (19) with single-hormone artificial pancreas, dual-hormone artificial pancreas, and conventional insulin pump therapy, respectively. The mean difference in time spent in the target range between single-hormone artificial pancreas and conventional insulin pump therapy was 11% (17; p=0·002) and between dual-hormone artificial pancreas and conventional insulin pump therapy was 12% (21; p=0·00011). There was no difference (15; p=0·75) in the proportion of time spent in the target range between the single-hormone and dual-hormone artificial pancreas systems. There were 52 hypoglycaemic events with conventional insulin pump therapy (12 of which were symptomatic), 13 with the single-hormone artificial pancreas (five of which were symptomatic), and nine with the dual-hormone artificial pancreas (0 of which were symptomatic); the number of nocturnal hypoglycaemic events was 13 (0 symptomatic), 0, and 0, respectively. INTERPRETATION: Single-hormone and dual-hormone artificial pancreas systems both provided better glycaemic control than did conventional insulin pump therapy. The single-hormone artificial pancreas might be sufficient for hypoglycaemia-free overnight glycaemic control. FUNDING: Canadian Diabetes Association; Fondation J A De Sève; Juvenile Diabetes Research Foundation; and Medtronic.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Glucagon/administração & dosagem , Hipoglicemia/prevenção & controle , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Pâncreas Artificial , Adolescente , Adulto , Idoso , Glicemia/metabolismo , Criança , Estudos Cross-Over , Diabetes Mellitus Tipo 1/sangue , Quimioterapia Combinada , Glucagon/uso terapêutico , Humanos , Hipoglicemiantes/uso terapêutico , Bombas de Infusão Implantáveis , Insulina/uso terapêutico , Sistemas de Infusão de Insulina , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
18.
Cereb Cortex ; 25(1): 35-45, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23960212

RESUMO

Traumatic brain injury (TBI) and its consequences represent one of the leading causes of death in young adults. This lesion mediates glial activation and the release of harmful molecules and causes brain edema, axonal injury, and functional impairment. Since glial activation plays a key role in the development of this damage, it seems that controlling it could be beneficial and could lead to neuroprotective effects. Recent studies show that minocycline suppresses microglial activation, reduces the lesion volume, and decreases TBI-induced locomotor hyperactivity up to 3 months. The endocannabinoid system (ECS) plays an important role in reparative mechanisms and inflammation under pathological situations by controlling some mechanisms that are shared with minocycline pathways. We hypothesized that the ECS could be involved in the neuroprotective effects of minocycline. To address this hypothesis, we used a murine TBI model in combination with selective CB1 and CB2 receptor antagonists (AM251 and AM630, respectively). The results provided the first evidence for the involvement of ECS in the neuroprotective action of minocycline on brain edema, neurological impairment, diffuse axonal injury, and microglial activation, since all these effects were prevented by the CB1 and CB2 receptor antagonists.


Assuntos
Lesões Encefálicas/metabolismo , Encéfalo/efeitos dos fármacos , Microglia/efeitos dos fármacos , Minociclina/farmacologia , Fármacos Neuroprotetores/farmacologia , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Animais , Axônios/efeitos dos fármacos , Axônios/patologia , Edema Encefálico/metabolismo , Lesões Encefálicas/patologia , Antagonistas de Receptores de Canabinoides/farmacologia , Indóis/farmacologia , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Piperidinas/farmacologia , Pirazóis/farmacologia , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB2 de Canabinoide/antagonistas & inibidores
19.
Diabetes Res Clin Pract ; 106(3): 420-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25451901

RESUMO

AIMS: To describe (i) current bedtime nutritional practices and (ii) the association between post-dinner dietary intake and the occurrence of non-severe nocturnal hypoglycemia (NH) in real-life conditions among adult patients with type 1 diabetes using insulin analogs. METHODS: One hundred adults (median [interquartile range]: age 46.4 [36.0-55.8] years, HbA1c 7.9 [7.3-8.6] % (63 [56-70] mmol/mol)) using multiple daily injections (n=67) or insulin pump (n=33) wore a blinded continuous glucose monitoring system and completed a food diary for 72-h. RESULTS: NH occurred on 28% of 282 nights analyzed. (i) Patients reported post-dinner dietary intakes on 63% of the evenings. They injected rapid-acting insulin boluses on 64 occasions (23% of 282 evenings). These insulin boluses were mostly injected with (n=37) dietary intakes. (ii) Post-dinner dietary intake was not associated with NH occurrence in univariate analyses. In multivariate analyses, the injection of rapid-acting insulin modulated the association between post-dinner dietary intake and NH: with insulin, post-dinner carbohydrate intake was positively associated with NH (odds ratio (OR): 1.16 [95% confidence interval, CI: 1.04-1.29] per 5g increase, p=0.008); without insulin, post-dinner protein intake was inversely associated with NH occurrence (OR [95% CI]: 0.88 [0.78-1.00] per 2g increase, p=0.048). CONCLUSIONS: NH remains frequent in adults with type 1 diabetes. There is a complex relationship between post-dinner dietary intake and NH occurrence, including the significant role of nutrient content and rapid-acting insulin injection that requires further investigation.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 1/tratamento farmacológico , Suplementos Nutricionais , Hipoglicemia/induzido quimicamente , Insulina Isófana/uso terapêutico , Monitorização Fisiológica/métodos , Período Pós-Prandial , Adulto , Estudos Transversais , Diabetes Mellitus Tipo 1/dietoterapia , Feminino , Seguimentos , Humanos , Hipoglicemia/sangue , Hipoglicemia/epidemiologia , Hipoglicemiantes/uso terapêutico , Incidência , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Quebeque/epidemiologia , Fatores de Risco
20.
PLoS One ; 9(10): e110776, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25329809

RESUMO

BACKGROUND: Neuro- and vasoprotective effects of poly(ADP-ribose)polymerase (PARP) inhibition have been largely documented in models of cerebral ischemia, particularly with the potent PARP inhibitor PJ34. Furthermore, after ischemic stroke, physicians are faced with incomplete tissue reperfusion and reocclusion, in which platelet activation/aggregation plays a key role. Data suggest that certain PARP inhibitors could act as antiplatelet agents. In that context, the present in vitro study investigated on human blood the potential antiplatelet effect of PJ34 and two structurally different PARP inhibitors, DPQ and INO-1001. METHODS AND RESULTS: ADP concentrations were chosen to induce a biphasic aggregation curve resulting from the successive activation of both its receptors P2Y(1) and P2Y(12). In these experimental conditions, PJ34 inhibited the second phase of aggregation; this effect was reduced by incremental ADP concentrations. In addition, in line with a P2Y(12) pathway inhibitory effect, PJ34 inhibited the dephosphorylation of the vasodilator stimulated phosphoprotein (VASP) in a concentration-dependent manner. Besides, PJ34 had no effect on platelet aggregation induced by collagen or PAR1 activating peptide, used at concentrations inducing a strong activation independent on secreted ADP. By contrast, DPQ and INO-1001 were devoid of any effect whatever the platelet agonist used. CONCLUSIONS: We showed that, in addition to its already demonstrated beneficial effects in in vivo models of cerebral ischemia, the potent PARP inhibitor PJ34 exerts in vitro an antiplatelet effect. Moreover, this is the first study to report that PJ34 could act via a competitive P2Y(12) antagonism. Thus, this antiplatelet effect could improve post-stroke reperfusion and/or prevent reocclusion, which reinforces the interest of this drug for stroke treatment.


Assuntos
Plaquetas/metabolismo , Fenantrenos/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Inibidores de Poli(ADP-Ribose) Polimerases , Receptores Purinérgicos P2Y12/metabolismo , Difosfato de Adenosina/metabolismo , Feminino , Humanos , Masculino , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/metabolismo
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