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The frequency-following response (FFR) is an evoked potential that provides a neural index of complex sound encoding in the brain. FFRs have been widely used to characterize speech and music processing, experience-dependent neuroplasticity (e.g., learning and musicianship), and biomarkers for hearing and language-based disorders that distort receptive communication abilities. It is widely assumed that FFRs stem from a mixture of phase-locked neurogenic activity from the brainstem and cortical structures along the hearing neuraxis. In this study, we challenge this prevailing view by demonstrating that upwards of ~50% of the FFR can originate from an unexpected myogenic source: contamination from the postauricular muscle (PAM) vestigial startle reflex. We measured PAM, transient auditory brainstem responses (ABRs), and sustained frequency-following response (FFR) potentials reflecting myogenic (PAM) and neurogenic (ABR/FFR) responses in young, normal-hearing listeners with varying degrees of musical training. We first establish that PAM artifact is present in all ears, varies with electrode proximity to the muscle, and can be experimentally manipulated by directing listeners' eye gaze toward the ear of sound stimulation. We then show this muscular noise easily confounds auditory FFRs, spuriously amplifying responses 3-4-fold with tandem PAM contraction and even explaining putative FFR enhancements observed in highly skilled musicians. Our findings expose a new and unrecognized myogenic source to the FFR that drives its large inter-subject variability and cast doubt on whether changes in the response typically attributed to neuroplasticity/pathology are solely of brain origin.
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Background: Plasticity from auditory experience shapes the brain's encoding and perception of sound. Though prior research demonstrates that neural entrainment (i.e., brain-to-acoustic synchronization) aids speech perception, how long- and short-term plasticity influence entrainment to concurrent speech has not been investigated. Here, we explored neural entrainment mechanisms and the interplay between short- and long-term neuroplasticity for rapid auditory perceptual learning of concurrent speech sounds in young, normal-hearing musicians and nonmusicians. Method: Participants learned to identify double-vowel mixtures during â¼45 min training sessions with concurrent high-density EEG recordings. We examined the degree to which brain responses entrained to the speech-stimulus train (â¼9 Hz) to investigate whether entrainment to speech prior to behavioral decision predicted task performance. Source and directed functional connectivity analyses of the EEG probed whether behavior was driven by group differences auditory-motor coupling. Results: Both musicians and nonmusicians showed rapid perceptual learning in accuracy with training. Interestingly, listeners' neural entrainment strength prior to target speech mixtures predicted behavioral identification performance; stronger neural synchronization was observed preceding incorrect compared to correct trial responses. We also found stark hemispheric biases in auditory-motor coupling during speech entrainment, with greater auditory-motor connectivity in the right compared to left hemisphere for musicians (R>L) but not in nonmusicians (R=L). Conclusions: Our findings confirm stronger neuroacoustic synchronization and auditory-motor coupling during speech processing in musicians. Stronger neural entrainment to rapid stimulus trains preceding incorrect behavioral responses supports the notion that alpha-band (â¼10 Hz) arousal/suppression in brain activity is an important modulator of trial-by-trial success in perceptual processing.
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Plasticity from auditory experience shapes the brain's encoding and perception of sound. However, whether such long-term plasticity alters the trajectory of short-term plasticity during speech processing has yet to be investigated. Here, we explored the neural mechanisms and interplay between short- and long-term neuroplasticity for rapid auditory perceptual learning of concurrent speech sounds in young, normal-hearing musicians and nonmusicians. Participants learned to identify double-vowel mixtures during ~ 45 min training sessions recorded simultaneously with high-density electroencephalography (EEG). We analyzed frequency-following responses (FFRs) and event-related potentials (ERPs) to investigate neural correlates of learning at subcortical and cortical levels, respectively. Although both groups showed rapid perceptual learning, musicians showed faster behavioral decisions than nonmusicians overall. Learning-related changes were not apparent in brainstem FFRs. However, plasticity was highly evident in cortex, where ERPs revealed unique hemispheric asymmetries between groups suggestive of different neural strategies (musicians: right hemisphere bias; nonmusicians: left hemisphere). Source reconstruction and the early (150-200 ms) time course of these effects localized learning-induced cortical plasticity to auditory-sensory brain areas. Our findings reinforce the domain-general benefits of musicianship but reveal that successful speech sound learning is driven by a critical interplay between long- and short-term mechanisms of auditory plasticity, which first emerge at a cortical level.
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Córtex Auditivo , Percepção da Fala , Humanos , Fala , Percepção da Fala/fisiologia , Córtex Auditivo/fisiologia , Aprendizagem , Eletroencefalografia , Plasticidade Neuronal/fisiologia , Estimulação AcústicaRESUMO
ABSTRACT: Glycoprotein Ibα (GPIbα) is expressed on the surface of platelets and megakaryocytes (MKs) and anchored to the membrane skeleton by filamin A (flnA). Although GPIb and flnA have fundamental roles in platelet biogenesis, the nature of this interaction in megakaryocyte biology remains ill-defined. We generated a mouse model expressing either human wild-type (WT) GPIbα (hGPIbαWT) or a flnA-binding mutant (hGPIbαFW) and lacking endogenous mouse GPIbα. Mice expressing the mutant GPIbα transgene exhibited macrothrombocytopenia with preserved GPIb surface expression. Platelet clearance was normal and differentiation of MKs to proplatelets was unimpaired in hGPIbαFW mice. The most striking abnormalities in hGPIbαFW MKs were the defective formation of the demarcation membrane system (DMS) and the redistribution of flnA from the cytoplasm to the peripheral margin of MKs. These abnormalities led to disorganized internal MK membranes and the generation of enlarged megakaryocyte membrane buds. The defective flnA-GPIbα interaction also resulted in misdirected release of buds away from the vasculature into bone marrow interstitium. Restoring the linkage between flnA and GPIbα corrected the flnA redistribution within MKs and DMS ultrastructural defects as well as restored normal bud size and release into sinusoids. These studies define a new mechanism of macrothrombocytopenia resulting from dysregulated MK budding. The link between flnA and GPIbα is not essential for the MK budding process, however, it plays a major role in regulating the structure of the DMS, bud morphogenesis, and the localized release of buds into the circulation.
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Megacariócitos , Complexo Glicoproteico GPIb-IX de Plaquetas , Trombocitopenia , Animais , Humanos , Camundongos , Plaquetas/metabolismo , Citoplasma/metabolismo , Filaminas/genética , Filaminas/metabolismo , Megacariócitos/metabolismo , Morfogênese , Complexo Glicoproteico GPIb-IX de Plaquetas/genética , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Trombocitopenia/genética , Trombocitopenia/metabolismoRESUMO
The frequency-following response (FFR) is an evoked potential that provides a "neural fingerprint" of complex sound encoding in the brain. FFRs have been widely used to characterize speech and music processing, experience-dependent neuroplasticity (e.g., learning, musicianship), and biomarkers for hearing and language-based disorders that distort receptive communication abilities. It is widely assumed FFRs stem from a mixture of phase-locked neurogenic activity from brainstem and cortical structures along the hearing neuraxis. Here, we challenge this prevailing view by demonstrating upwards of ~50% of the FFR can originate from a non-neural source: contamination from the postauricular muscle (PAM) vestigial startle reflex. We first establish PAM artifact is present in all ears, varies with electrode proximity to the muscle, and can be experimentally manipulated by directing listeners' eye gaze toward the ear of sound stimulation. We then show this muscular noise easily confounds auditory FFRs, spuriously amplifying responses by 3-4x fold with tandem PAM contraction and even explaining putative FFR enhancements observed in highly skilled musicians. Our findings expose a new and unrecognized myogenic source to the FFR that drives its large inter-subject variability and cast doubt on whether changes in the response typically attributed to neuroplasticity/pathology are solely of brain origin.
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OBJECTIVE: This trial examined the effects of proximal/distal mediators and moderators of an Active Music Engagement (AME) intervention on young child/parent distress, quality of life, and family function outcomes. METHODS: Child/parent dyads (n = 125) were randomized to AME or Audio-storybooks attention control condition. Each group received 3 sessions with a credentialed music therapist for 3 consecutive days with data collection at baseline, post-intervention (T2), and 30-days later (T3). Potential proximal mediators included within session child and parent engagement. Potential distal mediators included changes in perceived family normalcy, parent self-efficacy, and independent use of play materials. Potential moderators included parent/child distress with prior hospitalizations, parent traumatic stress screener (PCL-6), and child age. Outcomes included child emotional distress and quality of life; parent emotion, traumatic stress symptoms (IES-R), well-being; and family function. Mediation effects were estimated using ANCOVA, with indirect effects estimated using the percentile bootstrap approach. Moderation effects were tested by including appropriate interaction terms in models. RESULTS: No significant mediation effects were observed. Child distress with prior hospitalizations moderated AME effects for IES-R intrusion subscale scores at T2 (P = .01) and avoidance subscale scores at T3 (P = .007). Traumatic stress screener scores (PCL-6) moderated intervention effects for IES-R hyperarousal subscale scores at T2 (P = .01). There were no moderation effects for child age. CONCLUSIONS: AME is a promising intervention for mitigating traumatic stress symptoms and supporting well-being in parents of children with cancer, particularly for parents who screen high for traumatic stress and whose children are more highly distressed with hospitalization.
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Musicoterapia , Neoplasias , Pais , Transtornos de Estresse Traumático , Criança , Pré-Escolar , Humanos , Emoções , Música , Neoplasias/psicologia , Pais/psicologia , Qualidade de Vida , Transtornos de Estresse Traumático/etiologia , Transtornos de Estresse Traumático/psicologia , Transtornos de Estresse Traumático/terapiaRESUMO
Plasticity from auditory experiences shapes brain encoding and perception of sound. However, whether such long-term plasticity alters the trajectory of short-term plasticity during speech processing has yet to be investigated. Here, we explored the neural mechanisms and interplay between short- and long-term neuroplasticity for rapid auditory perceptual learning of concurrent speech sounds in young, normal-hearing musicians and nonmusicians. Participants learned to identify double-vowel mixtures during â¼45 minute training sessions recorded simultaneously with high-density EEG. We analyzed frequency-following responses (FFRs) and event-related potentials (ERPs) to investigate neural correlates of learning at subcortical and cortical levels, respectively. While both groups showed rapid perceptual learning, musicians showed faster behavioral decisions than nonmusicians overall. Learning-related changes were not apparent in brainstem FFRs. However, plasticity was highly evident in cortex, where ERPs revealed unique hemispheric asymmetries between groups suggestive of different neural strategies (musicians: right hemisphere bias; nonmusicians: left hemisphere). Source reconstruction and the early (150-200 ms) time course of these effects localized learning-induced cortical plasticity to auditory-sensory brain areas. Our findings confirm domain-general benefits for musicianship but reveal successful speech sound learning is driven by a critical interplay between long- and short-term mechanisms of auditory plasticity that first emerge at a cortical level.
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Although humans have long been predators with enduring nutritive and cultural relationships with their prey, seldom have conservation ecologists considered the divergent predatory behavior of contemporary, industrialized humans. Recognizing that the number, strength and diversity of predator-prey relationships can profoundly influence biodiversity, here we analyze humanity's modern day predatory interactions with vertebrates and estimate their ecological consequences. Analysing IUCN 'use and trade' data for ~47,000 species, we show that fishers, hunters and other animal collectors prey on more than a third (~15,000 species) of Earth's vertebrates. Assessed over equivalent ranges, humans exploit up to 300 times more species than comparable non-human predators. Exploitation for the pet trade, medicine, and other uses now affects almost as many species as those targeted for food consumption, and almost 40% of exploited species are threatened by human use. Trait space analyses show that birds and mammals threatened by exploitation occupy a disproportionally large and unique region of ecological trait space, now at risk of loss. These patterns suggest far more species are subject to human-imposed ecological (e.g., landscapes of fear) and evolutionary (e.g., harvest selection) processes than previously considered. Moreover, continued overexploitation will likely bear profound consequences for biodiversity and ecosystem function.
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Ecossistema , Ursidae , Animais , Comportamento Predatório , Biodiversidade , Evolução Biológica , EcologiaRESUMO
CHARGE syndrome typically results from mutations in the gene encoding chromodomain helicase DNA-binding protein 7 (CHD7). CHD7 is involved in regulating neural crest development, which gives rise to tissues of the skull/face and the autonomic nervous system (ANS). Individuals with CHARGE syndrome are frequently born with anomalies requiring multiple surgeries and often experience adverse events post-anesthesia, including oxygen desaturations, decreased respiratory rates, and heart rate abnormalities. Central congenital hypoventilation syndrome (CCHS) affects ANS components that regulate breathing. Its hallmark feature is hypoventilation during sleep, clinically resembling observations in anesthetized CHARGE patients. Loss of PHOX2B (paired-like homeobox 2b) underlies CCHS. Employing a chd7-null zebrafish model, we investigated physiologic responses to anesthesia and compared these to loss of phox2b. Heart rates were lower in chd7 mutants compared to the wild-type. Exposure to tricaine, a zebrafish anesthetic/muscle relaxant, revealed that chd7 mutants took longer to become anesthetized, with higher respiratory rates during recovery. chd7 mutant larvae demonstrated unique phox2ba expression patterns. The knockdown of phox2ba reduced larval heart rates similar to chd7 mutants. chd7 mutant fish are a valuable preclinical model to investigate anesthesia in CHARGE syndrome and reveal a novel functional link between CHARGE syndrome and CCHS.
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Síndrome CHARGE , Proteínas de Peixe-Zebra , Peixe-Zebra , Animais , Síndrome CHARGE/genética , Hipoventilação/genética , Hipoventilação/congênito , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismoRESUMO
BACKGROUND: Music therapy is a standard palliative care service in many pediatric and adult hospitals; however, most research has focused on the use of music to improve psychosocial dimensions of health, without considering biological dimensions. This study builds on prior work examining psychosocial mechanisms of action underlying an Active Music Engagement (AME) intervention, designed to help manage emotional distress and improve positive health outcomes in young children with cancer and parents (caregivers), by examining its effects on biomarkers of stress and immune function. METHODS: This two-group randomized controlled trial (R01NR019190) is designed to examine biological mechanisms of effect and dose-response relationships of AME on child/parent stress during the consolidation phase of Acute B- or T-cell Lymphoblastic Leukemia (ALL) and T-cell Lymphoblastic Lymphoma (TLyLy) treatment. Child/parent dyads (n = 228) are stratified (by age, site, risk level) and randomized in blocks of four to the AME or attention control condition. Each group receives one session (30-minutes AME; 20-minutes control) during weekly clinic visits (4 weeks standard risk B-cell ALL; 8 weeks high risk B-cell ALL/T-cell ALL/TLyLy). Parents complete questionnaires at baseline and post-intervention. Child/parent salivary cortisol samples are taken pre- and post-session (sessions 1-4). Child blood samples are reserved from routine draws before sessions 1 and 4 (all participants) and session 8 (high risk participants). We will use linear mixed models to estimate AME's effect on child/parent cortisol. Examining child/parent cortisol as mediators of AME effects on child and parent outcomes will be performed in an ANCOVA setting, fitting the appropriate mediation models using MPlus and then testing indirect effects using the percentile bootstrap approach. Graphical plots and non-linear repeated measures models will be used to examine dose-response relationship of AME on child/parent cortisol. DISCUSSION: During pediatric cancer treatment there are special challenges that must be considered when measuring cortisol and immune function. In this manuscript we discuss how we addressed three specific challenges through our trial design. Findings from this trial will increase mechanistic understanding of the effects of active music interventions on multiple biomarkers and understanding of dose-response effects, with direct implications for clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04400071.
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Linfoma , Música , Leucemia-Linfoma Linfoblástico de Células Precursoras , Adulto , Humanos , Criança , Pré-Escolar , Hidrocortisona , Pais/psicologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Biomarcadores , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Extracellular protein disulfide isomerases (PDIs), including PDI, endoplasmic reticulum protein 57 (ERp57), ERp72, ERp46, and ERp5, are required for in vivo thrombus formation in mice. Platelets secrete PDIs upon activation, which regulate platelet aggregation. However, platelets secrete only â¼10% of their PDI content extracellularly. The intracellular role of PDIs in platelet function is unknown. Here, we aim to characterize the role of ERp5 (gene Pdia6) using platelet conditional knockout mice, platelet factor 4 (Pf4) Cre+/ERp5floxed (fl)/fl. Pf4Cre+/ERp5fl/fl mice developed mild macrothrombocytopenia. Platelets deficient in ERp5 showed marked dysregulation of their ER, indicated by a twofold upregulation of ER proteins, including PDI, ERp57, ERp72, ERp46, 78 kilodalton glucose-regulated protein (GRP78), and calreticulin. ERp5-deficient platelets showed an enhanced ER stress response to ex vivo and in vivo ER stress inducers, with enhanced phosphorylation of eukaryotic translation initiation factor 2A and inositol-requiring enzyme 1 (IRE1). ERp5 deficiency was associated with increased secretion of PDIs, an enhanced response to thromboxane A2 receptor activation, and increased thrombus formation in vivo. Our results support that ERp5 acts as a negative regulator of ER stress responses in platelets and highlight the importance of a disulfide isomerase in platelet ER homeostasis. The results also indicate a previously unanticipated role of platelet ER stress in platelet secretion and thrombosis. This may have important implications for the therapeutic applications of ER stress inhibitors in thrombosis.
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Plaquetas , Trombose , Animais , Camundongos , Plaquetas/metabolismo , Agregação Plaquetária , Isomerases de Dissulfetos de Proteínas/genética , Isomerases de Dissulfetos de Proteínas/metabolismo , Hemostasia , Trombose/metabolismoRESUMO
Treatment fidelity is the use of methodological strategies to monitor and enhance reliability and validity of behavioral intervention trials. Despite availability of guidelines and checklists, treatment fidelity remains underreported, hindering evaluation, interpretation, and cross-study comparisons. Treatment fidelity is particularly important for music interventions given the inherent complexity of musical stimuli and flexibility required for tailored delivery. The purpose of this paper is to define and describe treatment fidelity strategies for our trial of a music-based play intervention for young children with cancer and parents grounded in the NIH Behavior Change Consortium Treatment Fidelity Recommendations. We report strategies for all 5 areas: study design, training providers, delivery of treatment, receipt of treatment, and enactment of treatment skills. We also discuss 4 challenges our team encountered, including: (1) standardizing live music delivery, (2) defining boundaries for tailored intervention delivery, (3) managing extended time between participants, and (4) minimizing risk for bias. This paper expands on current fidelity literature and may provide a working model for other investigators examining dyadic and/or active music interventions.
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Terapia Comportamental , Neoplasias , Criança , Humanos , Pré-Escolar , Reprodutibilidade dos Testes , Neoplasias/terapia , Projetos de PesquisaRESUMO
Background: Diagnosis and treatment of cancer and blood disorders in childhood, adolescence and young adulthood has a significant impact on patients and families. The Psychosocial Standards of Care project, initiated in 2012, resulted in 15 Psychosocial Standards (PSS) that guide the care patients and families receive throughout treatment. As members of the multidisciplinary psychosocial care team, music therapists play an important role in the advancing the PSS. Most surveys have focused on other commonly provided services (e.g., social work, child life), leaving gaps in our understanding about the availability and use of music therapy services to advance PSS. This paper offers an initial description of how music therapy services contribute to the provision of care under these Standards. Methods: We analyze how music therapy services promote PSS through synthesis of a music therapy clinical practice survey, published literature, and scope of practice documents. A brief overview of music therapy services structure, PSS that music therapy services currently address, and two clinical program descriptions are included. Results: Music therapy services address 9 of the 15 PSS and are well integrated within the larger program of psychosocial care. Findings suggest integration of music therapy services can help ensure personalized, comprehensive care and efficient use of often-limited psychosocial care resources. Discussion: Nurses, as members of the psychosocial and medical teams are uniquely positioned to identify patient and family care needs and refer patients for services. Understanding how music therapy services address PSS and most importantly, the needs of patients and families, will optimize their care.
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Doenças Hematológicas , Musicoterapia , Reabilitação Psiquiátrica , Adolescente , Adulto , Criança , Família , Humanos , Oncologia , Musicoterapia/métodos , Inquéritos e Questionários , Adulto JovemRESUMO
Recanalization with restored cerebral perfusion is the primary goal of thrombolytic therapy in acute ischemic stroke. The identification of adjunctive therapies that can be safely used to enhance thrombolysis in stroke remains an elusive goal. We report here the development of a mouse in situ carotid artery thrombolysis (iCAT) stroke model involving graded cerebral ischemia to induce unihemispheric infarction after thrombotic occlusion of the common carotid artery (CCA). Electrolytic-induced thrombotic occlusion of the left CCA enabled real-time assessment of recanalization and rethrombosis events after thrombolysis with recombinant tissue-type plasminogen activator (rtPA). Concurrent transient stenosis of the right CCA induced unihemispheric hypoperfusion and infarction in the left middle cerebral artery territory. Real-time assessment of thrombolysis revealed recanalization rates <30% in rtPA-treated animals with high rates of rethrombosis. Addition of the direct thrombin inhibitor argatroban increased recanalization rates to 50% and reduced rethrombosis. Paradoxically, this was associated with increased cerebral ischemia and stroke-related mortality (25%-42%). Serial analysis of carotid and cerebral blood flow showed that coadministration of argatroban with rtPA resulted in a marked increase in carotid artery embolization, leading to distal obstruction of the middle cerebral artery. Real-time imaging of carotid thrombi revealed that adjunctive anticoagulation destabilized platelet-rich thrombi at the vessel wall, leading to dislodgement of large platelet emboli. These studies confirm the benefits of anticoagulants in enhancing thrombolysis and large artery recanalization; however, at high levels of anticoagulation (â¼3-fold prolongation of activated partial thromboplastin time), this effect is offset by increased incidence of carotid artery embolization and distal middle cerebral artery occlusion. The iCAT stroke model should provide important new insight into the effects of adjunctive antithrombotic agents on real-time thrombus dynamics during thrombolysis and their correlation with stroke outcomes.
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Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Tromboembolia , Animais , Anticoagulantes/uso terapêutico , Antitrombinas/uso terapêutico , Arginina/análogos & derivados , Isquemia Encefálica/complicações , Isquemia Encefálica/tratamento farmacológico , Artéria Carótida Primitiva , Fibrinolíticos/farmacologia , Fibrinolíticos/uso terapêutico , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/tratamento farmacológico , Camundongos , Ácidos Pipecólicos , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/etiologia , Sulfonamidas , Terapia Trombolítica/efeitos adversos , Terapia Trombolítica/métodos , Ativador de Plasminogênio Tecidual/farmacologia , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do TratamentoRESUMO
The role of cardiac fibroblasts (CFs) in disease states has been a focus of cardiovascular research over the past decade. Here, we briefly describe methods for isolation and characterization of CFs from adult mouse ventricles. Primary cultures were stained using antibodies for several marker proteins such as α-smooth muscle actin (αSMA), vimentin, and discoidin domain receptor 2 (DDR2) to confirm the identity of CFs or cardiac myofibroblasts (CMFs). Most cells in primary cultures consisted of CFs, with very low frequencies of endothelial cells, cardiomyocytes, and smooth muscle cells. We compared marker expression between cultures that were not passaged (P0) or passaged for few times (P1-3). When compared with P1-3 cultures, P0 cultures consistently displayed a lower percentage of cells positive for αSMA and DDR2, whereas vimentin expression was significantly higher in P0 cultures compared with P1-3 cultures. P0 cells were also smaller in area than P1-3 cells. Further, P1-3 mouse CFs were found to express both ß1 and ß2 adrenergic receptors (ARs) and ß1ARs were more readily detected on the cell surface compared with ß2ARs. In summary, mouse CF cultures underwent phenotype conversion into CMFs after passaging, consistent with what is seen with CF cultures from other species.
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Miofibroblastos/citologia , Animais , Diferenciação Celular , Células Cultivadas , Camundongos , Miócitos de Músculo Liso/metabolismo , Miofibroblastos/metabolismo , Transdução de Sinais , Vimentina/metabolismoRESUMO
BACKGROUND: Central venous catheter (CVC) dysfunction is a common complication among pediatric cancer patients. Tissue plasminogen activator (tPA) is administered to resolve CVC dysfunction. The present study was designed to determine risk factors associated with requirement of tPA for CVC dysfunction and to assess the clinical impact of CVC dysfunction in terms of CVC loss and venous thrombotic events (VTE). PROCEDURE: Case records of all pediatric patients with cancer from the Maritimes, Canada were reviewed following ethics approval. Data regarding demographics, clinical diagnosis, CVC dysfunction, characteristics of CVCs, and VTE were pooled from multiple data sources. RESULTS: Seven hundred and forty-one patients required ≥1 CVC. 26.3% of patients required tPA for ≥1 episodes of CVC dysfunction. Requirement of one or more doses of tPA for episodes of CVC dysfunction increased the odds of VTE by two times (95% confidence interval, 1.1-3.6). Patients that required ≥1 doses of tPA required significantly more CVCs (2.05 ± 1.29 per individual patient, 55% of the patients needed >1 CVCs) as compared to the remainder (1.52 ± 0.95 per individual patient, 32% needed >1 CVCs) (P = 0.0001). Multivariate analysis revealed age > 10 years, diagnosis of sarcoma, and tunneled line were independently associated with tPA requirement. CONCLUSION: We determined independent risk factors associated with requirement of tPA for CVC dysfunction. Requirement of tPA for CVC dysfunction was associated with significantly increased risk of VTE and requirement of more CVCs. These observations can assist in identification of patients at increased risk of CVC dysfunction and inform approaches to reduce CVC loss and VTE.
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Cateterismo Venoso Central/efeitos adversos , Fibrinolíticos/uso terapêutico , Trombose/tratamento farmacológico , Ativador de Plasminogênio Tecidual/uso terapêutico , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Trombose/etiologiaRESUMO
Clot retraction refers to the process whereby activated platelets transduce contractile forces onto the fibrin network of a thrombus, which over time increases clot density and decreases clot size. This process is considered important for promoting clot stability and maintaining blood vessel patency. Insights into the mechanisms regulating clot retraction at sites of vascular injury have been hampered by a paucity of in vivo experimental models. By pairing localized vascular injury with thrombin microinjection in the mesenteric circulation of mice, we have demonstrated that the fibrin network of thrombi progressively compacts over a 2-hour period. This was a genuine retraction process, as treating thrombi with blebbistatin to inhibit myosin IIa-mediated platelet contractility prevented shrinkage of the fibrin network. Real-time confocal analysis of fibrinolysis after recombinant tissue-type plasminogen activator (tPA) administration revealed that incomplete proteolysis of fibrin polymers markedly facilitated clot retraction. Similarly, inhibiting endogenous fibrinolysis with tranexamic acid reduced retraction of fibrin polymers in vivo. In vitro clot retraction experiments indicated that subthreshold doses of tPA facilitated clot retraction through a plasmin-dependent mechanism. These effects correlated with changes in the elastic modulus of fibrin clots. These findings define the endogenous fibrinolytic system as an important regulator of clot retraction, and show that promoting clot retraction is a novel and complementary means by which fibrinolytic enzymes can reduce thrombus size.
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Retração do Coágulo , Fibrinólise , Actomiosina/metabolismo , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Fibrina/metabolismo , Fibrinólise/efeitos dos fármacos , Humanos , Masculino , Camundongos , Miosina não Muscular Tipo IIA/metabolismo , Trombose/diagnóstico por imagem , Trombose/metabolismo , Trombose/patologia , Ativador de Plasminogênio Tecidual/metabolismo , Ativador de Plasminogênio Tecidual/farmacologia , Ácido Tranexâmico/farmacologiaRESUMO
This corrects the article DOI: 10.1038/ncomms12862.
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Durational patterns provide cues to linguistic structure, thus so variations in rhythm skills may have consequences for language development. Understanding individual differences in rhythm skills, therefore, could help explain variability in language abilities across the population. We investigated the neural foundations of rhythmic proficiency and its relation to language skills in young adults. We hypothesized that rhythmic abilities can be characterized by at least two constructs, which are tied to independent language abilities and neural profiles. Specifically, we hypothesized that rhythm skills that require integration of information across time rely upon the consistency of slow, low-frequency auditory processing, which we measured using the evoked cortical response. On the other hand, we hypothesized that rhythm skills that require fine temporal precision rely upon the consistency of fast, higher-frequency auditory processing, which we measured using the frequency-following response. Performance on rhythm tests aligned with two constructs: rhythm sequencing and synchronization. Rhythm sequencing and synchronization were linked to the consistency of slow cortical and fast frequency-following responses, respectively. Furthermore, whereas rhythm sequencing ability was linked to verbal memory and reading, synchronization ability was linked only to nonverbal auditory temporal processing. Thus, rhythm perception at different time scales reflects distinct abilities, which rely on distinct auditory neural resources. In young adults, slow rhythmic processing makes the more extensive contribution to language skills.
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Percepção Auditiva/fisiologia , Córtex Cerebral/fisiologia , Potenciais Evocados/fisiologia , Individualidade , Idioma , Música , Percepção do Tempo/fisiologia , Adolescente , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
The 14-3-3 family of adaptor proteins regulate diverse cellular functions including cell proliferation, metabolism, adhesion and apoptosis. Platelets express numerous 14-3-3 isoforms, including 14-3-3ζ, which has previously been implicated in regulating GPIbα function. Here we show an important role for 14-3-3ζ in regulating arterial thrombosis. Interestingly, this thrombosis defect is not related to alterations in von Willebrand factor (VWF)-GPIb adhesive function or platelet activation, but instead associated with reduced platelet phosphatidylserine (PS) exposure and procoagulant function. Decreased PS exposure in 14-3-3ζ-deficient platelets is associated with more sustained levels of metabolic ATP and increased mitochondrial respiratory reserve, independent of alterations in cytosolic calcium flux. Reduced platelet PS exposure in 14-3-3ζ-deficient mice does not increase bleeding risk, but results in decreased thrombin generation and protection from pulmonary embolism, leading to prolonged survival. Our studies define an important role for 14-3-3ζ in regulating platelet bioenergetics, leading to decreased platelet PS exposure and procoagulant function.