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Ischemic stroke remains a leading cause of mortality and long-term disability worldwide, necessitating efforts to identify biomarkers for diagnosis, prognosis, and treatment monitoring. The present study aimed to identify novel plasma biomarkers of neurodegeneration and inflammation in a mouse model of stroke induced by distal middle cerebral artery (MCA) occlusion. Using targeted lipidomic and global untargeted metabolomic profiling of plasma collected from aged male mice 24 hours after stroke and weekly thereafter for 7 weeks, we discovered distinct acute and chronic signatures. In the acute phase, we observed elevations in myelin-associated lipids, including sphingomyelin (SM) and hexosylceramide (HCER) lipid species, indicating brain lipid catabolism. In the chronic phase, we identified 12-hydroxyeicosatetraenoic acid (12-HETE) as a putative biomarker of prolonged inflammation, consistent with our previous observation of a biphasic pro-inflammatory response to ischemia in the mouse brain. These results provide insight into the metabolic alterations detectable in the plasma after stroke and highlight the potential of myelin degradation products and arachidonic acid derivatives as biomarkers of neurodegeneration and inflammation, respectively. These discoveries lay the groundwork for further validation in human studies and may improve stroke management strategies.
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Globally, more than 67 million people are living with the effects of ischemic stroke. Importantly, many stroke survivors develop a chronic inflammatory response that may contribute to cognitive impairment, a common and debilitating sequela of stroke that is insufficiently studied and currently untreatable. 2-Hydroxypropyl-ß-cyclodextrin (HPßCD) is an FDA-approved cyclic oligosaccharide that can solubilize and entrap lipophilic substances. The goal of the present study was to determine whether the repeated administration of HPßCD curtails the chronic inflammatory response to stroke by reducing lipid accumulation within stroke infarcts in a distal middle cerebral artery occlusion mouse model of stroke. To achieve this goal, we subcutaneously injected young adult and aged male mice with vehicle or HPßCD 3 times per week, with treatment beginning 1 week after stroke. We evaluated mice at 7 weeks following stroke using immunostaining, RNA sequencing, lipidomic, and behavioral analyses. Chronic stroke infarct and peri-infarct regions of HPßCD-treated mice were characterized by an upregulation of genes involved in lipid metabolism and a downregulation of genes involved in innate and adaptive immunity, reactive astrogliosis, and chemotaxis. Correspondingly, HPßCD reduced the accumulation of lipid droplets, T lymphocytes, B lymphocytes, and plasma cells in stroke infarcts. Repeated administration of HPßCD also preserved NeuN immunoreactivity in the striatum and thalamus and c-Fos immunoreactivity in hippocampal regions. Additionally, HPßCD improved recovery through the protection of hippocampal-dependent spatial working memory and reduction of impulsivity. These results indicate that systemic HPßCD treatment following stroke attenuates chronic inflammation and secondary neurodegeneration and prevents poststroke cognitive decline.SIGNIFICANCE STATEMENT Dementia is a common and debilitating sequela of stroke. Currently, there are no available treatments for poststroke dementia. Our study shows that lipid metabolism is disrupted in chronic stroke infarcts, which causes an accumulation of uncleared lipid debris and correlates with a chronic inflammatory response. To our knowledge, these substantial changes in lipid homeostasis have not been previously recognized or investigated in the context of ischemic stroke. We also provide a proof of principle that solubilizing and entrapping lipophilic substances using HPßCD could be an effective strategy for treating chronic inflammation after stroke and other CNS injuries. We propose that using HPßCD for the prevention of poststroke dementia could improve recovery and increase long-term quality of life in stroke sufferers.
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2-Hidroxipropil-beta-Ciclodextrina/uso terapêutico , Encéfalo/efeitos dos fármacos , Infarto da Artéria Cerebral Média/tratamento farmacológico , Inflamação/tratamento farmacológico , Fatores Etários , Animais , Encéfalo/metabolismo , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/metabolismo , Inflamação/metabolismo , Masculino , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Resultado do TratamentoRESUMO
Inflammation is a crucial part of the healing process after an ischemic stroke and is required to restore tissue homeostasis. However, the inflammatory response to stroke also worsens neurodegeneration and creates a tissue environment that is unfavorable to regeneration for several months, thereby postponing recovery. In animal models, inflammation can also contribute to the development of delayed cognitive deficits. Myeloid cells that take on a foamy appearance are one of the most prominent immune cell types within chronic stroke infarcts. Emerging evidence indicates that they form as a result of mechanisms of myelin lipid clearance becoming overwhelmed, and that they are a key driver of the chronic inflammatory response to stroke. Therefore, targeting lipid accumulation in foam cells may be a promising strategy for improving recovery. The aim of this review is to provide an overview of current knowledge regarding inflammation and foam cell formation in the brain in the weeks and months following ischemic stroke and identify targets that may be amenable to therapeutic intervention.
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Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Animais , Células Espumosas/metabolismo , Acidente Vascular Cerebral/metabolismo , Isquemia Encefálica/metabolismo , Inflamação , LipídeosRESUMO
Following ischemic stroke, the degradation of myelin and other cellular membranes surpasses the lipid-processing capabilities of resident microglia and infiltrating macrophages. This imbalance leads to foam cell formation in the infarct and areas of secondary neurodegeneration, instigating sustained inflammation and furthering neurological damage. Given that mitochondria are the primary sites of fatty acid metabolism, augmenting mitochondrial biogenesis (MB) may enhance lipid processing, curtailing foam cell formation and post-stroke chronic inflammation. Previous studies have shown that the pharmacological activation of the ß2-adrenergic receptor (ß2-AR) stimulates MB. Consequently, our study sought to discern the effects of intensified ß2-AR signaling on MB, the processing of brain lipid debris, and neurological outcome using a mouse stroke model. To achieve this goal, aged mice were treated with formoterol, a long-acting ß2-AR agonist, daily for two and eight weeks following stroke. Formoterol increased MB in the infarct region, modified fatty acid metabolism, and reduced foam cell formation. However, it did not reduce markers of post-stroke neurodegeneration or improve recovery. Although our findings indicate that enhancing MB in myeloid cells can aid in the processing of brain lipid debris after stroke, it is important to note that boosting MB alone may not be sufficient to significantly impact stroke recovery.
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Biogênese de Organelas , Acidente Vascular Cerebral , Humanos , Células Espumosas/metabolismo , Fumarato de Formoterol/farmacologia , Acidente Vascular Cerebral/metabolismo , Encéfalo/metabolismo , Inflamação , Infarto , Ácidos Graxos , LipídeosRESUMO
The aim of this study was to test whether poststroke oral administration of a small molecule p75 neurotrophin receptor (p75NTR) modulator (LM11A-31) can augment neuronal survival and improve recovery in a mouse model of stroke. Mice were administered LM11A-31 for up to 12 weeks, beginning 1 week after stroke. Metabolomic analysis revealed that after 2 weeks of daily treatment, mice that received LM11A-31 were distinct from vehicle-treated mice by principal component analysis and had higher levels of serotonin, acetylcholine, and dopamine in their ipsilateral hemisphere. LM11A-31 treatment also improved redox homeostasis by restoring reduced glutathione. It also offset a stroke-induced reduction in glycolysis by increasing acetyl-CoA. There was no effect on cytokine levels in the infarct. At 13 weeks after stroke, adaptive immune cell infiltration in the infarct was unchanged in LM11A-31-treated mice, indicating that LM11A-31 does not alter the chronic inflammatory response to stroke at the site of the infarct. However, LM11A-31-treated mice had less brain atrophy, neurodegeneration, tau pathology, and microglial activation in other regions of the ipsilateral hemisphere. These findings correlated with improved recovery of motor function on a ladder test, improved sensorimotor and cognitive abilities on a nest construction test, and less impulsivity in an open field test. These data support small molecule modulation of the p75NTR for preserving neuronal health and function during stroke recovery. SIGNIFICANCE STATEMENT: The findings from this study introduce the p75 neurotrophin receptor as a novel small molecule target for promotion of stroke recovery. Given that LM11A-31 is in clinical trials as a potential therapy for Alzheimer's disease, it could be considered as a candidate for assessment in stroke or vascular dementia studies.
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Infarto da Artéria Cerebral Média/tratamento farmacológico , Isoleucina/análogos & derivados , Morfolinas/farmacologia , Fármacos Neuroprotetores/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Glutationa/metabolismo , Glicólise , Infarto da Artéria Cerebral Média/metabolismo , Isoleucina/farmacologia , Isoleucina/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Morfolinas/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Neurotransmissores/metabolismo , Receptor de Fator de Crescimento Neural/metabolismoRESUMO
A project with the goal of implementing electronic health record (EHR)-based patient-reported outcome measures (PROMs) into a large inpatient spinal cord injury (SCI) rehabilitation program took twice as long as expected. This report details the lessons learned from the barriers, successes, and unexpected issues that arose during this prolonged, but now successful, project. The goals of this implementation project were to (1) identify barriers and supports to the use of PROMs; (2) develop an implementation strategy to incorporate the use of PROMs into inpatient rehabilitation; and (3) implement the strategy and evaluate its effects on team communication. In brief, we conducted an initial pilot phase outside of the EHR and used our findings to guide procedural and EHR incorporation during a demonstration phase. We encountered multiple barriers. Procedural issues were significant; although grant funding covered the cost of writing the code for integration of the PROMs into the EHR, our institution's competing priorities slowed progress. Institutional inertia was reflected in the reluctance of some clinical staff members to assume new duties that would take away from direct patient care responsibilities. Therefore, we needed to obtain additional staffing. Detailed planning upfront, guided by changes when necessary; cooperation and interaction with our institution's Information Systems department; and identification of key players and Implementation Champions proved essential to our success. We now have an up-and-running system and are sharing our experience, observations, and recommendations to assist other health care organizations incorporate PROMs into their EHRs.
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Registros Eletrônicos de Saúde , Pacientes Internados , Comunicação , Humanos , Medidas de Resultados Relatados pelo PacienteRESUMO
BACKGROUND: Decreased cerebral blood flow and systemic inflammation during heart failure (HF) increase the risk for vascular contributions to cognitive impairment and dementia (VCID) and Alzheimer disease-related dementias (ADRD). We previously demonstrated that PNA5, a novel glycosylated angiotensin 1-7 (Ang-(1-7)) Mas receptor (MasR) agonist peptide, is an effective therapy to rescue cognitive impairment in our preclinical model of VCID. Neurofilament light (NfL) protein concentration is correlated with cognitive impairment and elevated in neurodegenerative diseases, hypoxic brain injury, and cardiac disease. The goal of the present study was to determine (1) if treatment with Ang-(1-7)/MasR agonists can rescue cognitive impairment and decrease VCID-induced increases in NfL levels as compared to HF-saline treated mice and, (2) if NfL levels correlate with measures of cognitive function and brain cytokines in our VCID model. METHODS: VCID was induced in C57BL/6 male mice via myocardial infarction (MI). At 5 weeks post-MI, mice were treated with daily subcutaneous injections for 24 days, 5 weeks after MI, with PNA5 or angiotensin 1-7 (500 microg/kg/day or 50 microg/kg/day) or saline (n = 15/group). Following the 24-day treatment protocol, cognitive function was assessed using the Novel Object Recognition (NOR) test. Cardiac function was measured by echocardiography and plasma concentrations of NfL were quantified using a Quanterix Simoa assay. Brain and circulating cytokine levels were determined with a MILLIPLEX MAP Mouse High Sensitivity Multiplex Immunoassay. Treatment groups were compared via ANOVA, significance was set at p < 0.05. RESULTS: Treatment with Ang-(1-7)/MasR agonists reversed VCID-induced cognitive impairment and significantly decreased NfL levels in our mouse model of VCID as compared to HF-saline treated mice. Further, NfL levels were significantly negatively correlated with cognitive scores and the concentrations of multiple pleiotropic cytokines in the brain. CONCLUSIONS: These data show that treatment with Ang-(1-7)/MasR agonists rescues cognitive impairment and decreases plasma NfL relative to HF-saline-treated animals in our VCID mouse model. Further, levels of NfL are significantly negatively correlated with cognitive function and with several brain cytokine concentrations. Based on these preclinical findings, we propose that circulating NfL might be a candidate for a prognostic biomarker for VCID and may also serve as a pharmacodynamic/response biomarker for therapeutic target engagement.
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Angiotensina I/agonistas , Angiotensina I/metabolismo , Disfunção Cognitiva/metabolismo , Citocinas/metabolismo , Demência Vascular/metabolismo , Proteínas de Neurofilamentos/metabolismo , Fragmentos de Peptídeos/agonistas , Fragmentos de Peptídeos/metabolismo , Angiotensina I/uso terapêutico , Animais , Biomarcadores/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/patologia , Demência Vascular/tratamento farmacológico , Demência Vascular/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/uso terapêutico , Prognóstico , Volume Sistólico/fisiologiaRESUMO
Up to 30% of stroke patients experience cognitive decline within one year of their stroke. There are currently no FDA-approved drugs that can prevent post-stroke cognitive decline, in part due to a poor understanding of the mechanisms involved. We have previously demonstrated that a B-lymphocyte response to stroke, marked by IgA + cells, can cause delayed cognitive dysfunction in mice and that a similar adaptive immune response occurs in the brains of some human stroke patients that suffer from vascular dementia. The stimuli which trigger B-lymphocyte activation following stroke, and their target antigens, are still unknown. Therefore, to learn more about the mechanisms by which B-lymphocytes become activated following stroke we first characterized the temporal kinetics of the B-lymphocyte, T-lymphocyte, and plasma cell (PC) response to stroke in the brain by immunohistochemistry (IHC). We discovered that B-lymphocyte, T-lymphocyte, and plasma cell infiltration within the infarct progressively increases between 2 and 7 weeks after stroke. We then compared the B-lymphocyte response to stroke in WT, MHCII-/-, CD4-/-, and MyD88-/- mice to determine if B-lymphocytes mature into IgA + PCs through a T-lymphocyte and MyD88 dependent mechanism. Our data from a combination of IHC and flow cytometry indicate that following stroke, a population of IgA + PCs develops independently of CD4 + helper T-lymphocytes and MyD88 signaling. Subsequent sequencing of immunoglobulin genes of individual IgA + PCs present within the infarct identified a novel population of natural antibodies with few somatic mutations in complementarity-determining regions. These findings indicate that a population of IgA + PCs develops in the infarct following stroke by B-lymphocytes interacting with one or more thymus independent type 2 (TI-2) antigens, and that they produce IgA natural antibodies.
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Ativação Linfocitária , Acidente Vascular Cerebral , Animais , Linfócitos B , Linfócitos T CD4-Positivos , Humanos , Imunoglobulina A , CamundongosRESUMO
OBJECTIVES: To develop item banks of social attitude barriers and facilitators to participation and validate them with established instruments. DESIGN: We used the Rasch model to identify misfitting items and rating scale problems, calibrate items, and develop KeyForms and short forms. Correlations between the Social Attitude Barriers and Facilitators item banks with the Patient-Reported Outcomes Measurement Information System (PROMIS) Social Health domain and National Institutes of Health Toolbox Emotional Battery Social Relationships domain were computed to evaluate convergent and divergent validity. SETTING: Community-dwelling individuals traveled to 3 academic medical centers for testing. PARTICIPANTS: Participants (N=558) who had a primary impairment of stroke, spinal cord injury, or traumatic brain injury (mean age, 47.0±16.0y) completed 31 social attitude facilitator and 51 barrier items using a 5-point rating scale. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Item banks to measure social attitude barriers and facilitators for individuals with disabilities. RESULTS: After combining the "never" and "rarely" rating scale categories, 30 Facilitator items fit the Rasch model and demonstrated person reliability of 0.93. After collapsing the "never" and "rarely" rating scale categories, 45 Barrier items fit the Rasch model and demonstrated person reliability of 0.95. Ceiling and floor effects were negligible for both item banks. Facilitators and Barriers item banks were negatively correlated, and these banks were moderately correlated with PROMIS and Toolbox measures, providing evidence of convergent and divergent validity. CONCLUSIONS: Findings support the reliability and validity of the Social Attitude Facilitators and Barriers item banks. These item banks allow investigators and clinicians to measure perceptions of social attitudes, providing information that can guide individual interventions to reduce barriers and promote facilitators. Moderate correlations between the Social Attitude banks and PROMIS and Toolbox variables provide support for the measurement and theory of environmental influences on social health and participation.
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Atitude Frente a Saúde , Pessoas com Deficiência/psicologia , Participação Social , Inquéritos e Questionários/normas , Adulto , Feminino , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , PsicometriaRESUMO
PURPOSE OF REVIEW: To review new evidence on links between poststroke dementia and inflammation. RECENT FINDINGS: Although there are still no treatments for poststroke dementia, recent evidence has improved our understanding that stroke increases the risk of incident dementia and worsens cognitive trajectory for at least a decade afterwards. Within approximately the first year dementia onset is associated with stroke severity and location, whereas later absolute risk is associated with more traditional dementia risk factors, such as age and imaging findings. The molecular mechanisms that underlie increased risk of incident dementia in stroke survivors remain unproven; however new data in both human and animal studies suggests links between cognitive decline and inflammation. These point to a model where chronic brain inflammation, provoked by inefficient clearance of myelin debris and a prolonged innate and adaptive immune response, causes poststroke dementia. These localized immune events in the brain may themselves be influenced by the peripheral immune state at key times after stroke. SUMMARY: This review recaps clinical evidence on poststroke dementia, new mechanistic links between the chronic inflammatory response to stroke and poststroke dementia, and proposes a model of immune-mediated neurodegeneration after stroke.
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Disfunção Cognitiva/etiologia , Demência/etiologia , Inflamação/etiologia , Acidente Vascular Cerebral/complicações , Disfunção Cognitiva/patologia , Demência/patologia , Humanos , Inflamação/patologia , Fatores de Risco , Acidente Vascular Cerebral/patologiaRESUMO
Microcirculatory damage is a common complication for those with vascular risk factors, such as diabetes. To resolve vascular insults, the brain's immune cells (microglia) must rapidly envelop the site of injury. Currently, it is unknown whether Type 1 diabetes, a condition associated with chronic immune system dysfunction, alters microglial responses to damage and what mechanisms are responsible. Using in vivo two-photon microscopy in adult male mice, we show that microglial envelopment of laser-induced cerebral microbleeds is diminished in a hyperglycemic mouse model of Type 1 diabetes, which could not be fully rescued with chronic insulin treatment. Microglia were important for vessel repair because reduced microglial accumulation in diabetic mice or near-complete depletion in healthy controls was associated with greater secondary leakage of the damaged vessel. Broadly suppressing inflammation with dexamethasone in diabetic mice but not healthy controls, significantly enhanced microglial responses to microbleeds and attenuated secondary vessel leakage. These enhancements were associated with changes in IFN-γ signaling because dexamethasone suppressed abnormally high levels of IFN-γ protein levels in brain and blood serum of diabetic mice. Further, blocking IFN-γ in diabetic mice with neutralizing antibodies restored normal microglial chemotaxic responses and purinoceptor P2ry12 gene expression, as well as mitigated secondary leakage. These results suggest that abnormal IFN-γ signaling disrupts microglial function in the diabetic brain, and that immunotherapies targeting IFN-γ can stimulate microglial repair of damaged vessels.SIGNIFICANCE STATEMENT Although Type 1 diabetes is an established risk factor for vascular complications, such as microbleeds, and is known to hinder wound healing in the body, no study has examined how diabetes impacts the brain's innate immune reparative response (involving cells called microglia) to vascular injury. Here we show that microglial responses to brain microbleeds were diminished in diabetic animals, which also exacerbated secondary leakage from damaged vessels. These impairments were related to abnormally high levels of the proinflammatory cytokine IFN-γ because reducing IFN-γ with immunosuppressant drugs or blocking antibodies helped restore normal microglial responses and repair of damaged vessels. These data highlight the use of IFN-γ modulating therapeutics to enhance vascular repair in at-risk populations.
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Córtex Cerebral/imunologia , Hemorragia Cerebral/imunologia , Diabetes Mellitus Tipo 1/imunologia , Interferon gama/imunologia , Microglia/imunologia , Animais , Córtex Cerebral/irrigação sanguínea , Hemorragia Cerebral/complicações , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/complicações , Modelos Animais de Doenças , Encefalite/sangue , Encefalite/complicações , Encefalite/imunologia , Masculino , Camundongos Endogâmicos C57BL , Imagem ÓpticaRESUMO
Increasing evidence indicates that decreased brain blood flow, increased reactive oxygen species (ROS) production, and proinflammatory mechanisms accelerate neurodegenerative disease progression such as that seen in vascular contributions to cognitive impairment and dementia (VCID) and Alzheimer's disease and related dementias. There is a critical clinical need for safe and effective therapies for the treatment and prevention of cognitive impairment known to occur in patients with VCID and chronic inflammatory diseases such as heart failure (HF), hypertension, and diabetes. This study used our mouse model of VCID/HF to test our novel glycosylated angiotensin-(1-7) peptide Ang-1-6-O-Ser-Glc-NH2 (PNA5) as a therapy to treat VCID and to investigate circulating inflammatory biomarkers that may be involved. We demonstrate that PNA5 has greater brain penetration compared with the native angiotensin-(1-7) peptide. Moreover, after treatment with 1.0/mg/kg, s.c., for 21 days, PNA5 exhibits up to 10 days of sustained cognitive protective effects in our VCID/HF mice that last beyond the peptide half-life. PNA5 reversed object recognition impairment in VCID/HF mice and rescued spatial memory impairment. PNA5 activation of the Mas receptor results in a dose-dependent inhibition of ROS in human endothelial cells. Last, PNA5 treatment decreased VCID/HF-induced activation of brain microglia/macrophages and inhibited circulating tumor necrosis factor α, interleukin (IL)-7, and granulocyte cell-stimulating factor serum levels while increasing that of the anti-inflammatory cytokine IL-10. These results suggest that PNA5 is an excellent candidate and "first-in-class" therapy for treating VCID and other inflammation-related brain diseases.
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Angiotensina I/química , Angiotensina I/farmacologia , Disfunção Cognitiva/complicações , Disfunção Cognitiva/tratamento farmacológico , Demência Vascular/complicações , Memória/efeitos dos fármacos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Proteínas Proto-Oncogênicas/agonistas , Receptores Acoplados a Proteínas G/agonistas , Angiotensina I/farmacocinética , Angiotensina I/uso terapêutico , Animais , Comportamento Animal/efeitos dos fármacos , Biomarcadores/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/fisiopatologia , Eletrocardiografia , Glicosilação , Meia-Vida , Insuficiência Cardíaca/complicações , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Inflamação/fisiopatologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Fragmentos de Peptídeos/farmacocinética , Fragmentos de Peptídeos/uso terapêutico , Proto-Oncogene Mas , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Memória Espacial/efeitos dos fármacos , Remodelação Ventricular/efeitos dos fármacosRESUMO
Following stroke, the damaged tissue undergoes liquefactive necrosis, a stage of infarct resolution that lasts for months although the exact length of time is currently unknown. One method of repair involves reactive astrocytes and microglia forming a glial scar to compartmentalize the area of liquefactive necrosis from the rest of the brain. The formation of the glial scar is a critical component of the healing response to stroke, as well as other central nervous system (CNS) injuries. The goal of this study was to evaluate the toxicity of the extracellular fluid present in areas of liquefactive necrosis and determine how effectively it is segregated from the remainder of the brain. To accomplish this goal, we used a mouse model of stroke in conjunction with an extracellular fluid toxicity assay, fluorescent and electron microscopy, immunostaining, tracer injections into the infarct, and multiplex immunoassays. We confirmed that the extracellular fluid present in areas of liquefactive necrosis following stroke is toxic to primary cortical and hippocampal neurons for at least 7â¯weeks following stroke, and discovered that although glial scars are robust physical and endocytic barriers, they are nevertheless permeable. We found that molecules present in the area of liquefactive necrosis can leak across the glial scar and are removed by a combination of paravascular clearance and microglial endocytosis in the adjacent tissue. Despite these mechanisms, there is delayed atrophy, cytotoxic edema, and neuron loss in regions adjacent to the infarct for weeks following stroke. These findings suggest that one mechanism of neurodegeneration following stroke is the failure of glial scars to impermeably segregate areas of liquefactive necrosis from surviving brain tissue.
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Infarto Cerebral/metabolismo , Cicatriz/metabolismo , Gliose/metabolismo , Neuroglia/metabolismo , Acidente Vascular Cerebral/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Infarto Cerebral/patologia , Cicatriz/patologia , Gliose/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neuroglia/patologia , Acidente Vascular Cerebral/patologiaRESUMO
Childhood cancer is increasing in prevalence whilst survival rates are improving. The prevalence of adult survivors of childhood cancer is consequently increasing. Many survivors suffer long-term consequences of their cancer treatment. Whilst many of these are well documented, relatively little is known about the mental health of survivors of childhood cancer. This article aimed to describe the prevalence and spectrum of mental health problems found in adult survivors of childhood cancer using a systematic review methodology. Our review included 67 articles, describing a number of problems, including depression, anxiety, behavioural problems and drug misuse. Factors increasing the likelihood of mental health problems included treatment with high-dose anthracyclines, cranial irradiation, diagnoses of sarcoma or central nervous system tumours and ongoing physical ill health. There were numerous limitations to the studies we found, including use of siblings of survivors as a control group, self-report methodology and lack of indications for prescriptions when prescribing data were used. This review has identified many mental health problems experienced by survivors of childhood cancer; however, the exact incidence, prevalence and risk-factors for their development remain unclear. Further work to identify childhood cancer patients who are at risk of developing late mental health morbidity is essential.
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Transtornos Mentais/etiologia , Saúde Mental , Neoplasias/complicações , Sobreviventes/psicologia , Adulto , Criança , Humanos , Transtornos Mentais/psicologia , Neoplasias/psicologia , Adulto JovemRESUMO
Post-stroke cognitive decline and dementia pose a significant public health problem, with 30% of stroke survivors suffering from dementia. The reason for this high prevalence is not well understood. Pathogenic B cell responses to the damaged CNS are one possible contributing factor. B-lymphocytes and antibodies are present in and around the stroke core of some human subjects who die with stroke and dementia, and mice that develop delayed cognitive dysfunction after stroke have clusters of B-lymphocytes in the stroke lesion, and antibody infiltration in the stroked hemisphere. The ablation of B-lymphocytes prevents post-stroke cognitive impairment in mice. Multiple drugs that target B cells are FDA approved, and so if pathogenic B cell responses are occurring in a subset of stroke patients, this is potentially treatable. However, it has also been demonstrated that regulatory B cells can be beneficial in mouse models of stroke. Consequently, it is important to understand the relative contribution of B-lymphocytes to recovery versus pathogenicity, and if this balance is heterogeneous in different individuals. Therefore, the purpose of this review is to summarize the current state of knowledge with regard to the role of B-lymphocytes in the etiology of post-stroke dementia.
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Autoimunidade , Linfócitos B/fisiologia , Demência/etiologia , Demência/imunologia , Acidente Vascular Cerebral/complicações , Animais , HumanosRESUMO
This case report provides an overview of the psychometric properties and clinical utility of the My Vocational Situation (MVS) instrument. The accompanying hypothetical case description illustrates how clinicians could use the MVS to evaluate vocational preferences and outcomes and how the MVS can be used to inform treatment planning and rehabilitation decision making. The information contained in this report is intended to familiarize clinicians with the administration and scoring of the MVS, the psychometric information necessary to interpret results obtained from the MVS, and how the results could be used to provide comprehensive, patient-centered care. It is important to note that the information provided represents only a sample of the available research literature on the MVS.
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Acidentes de Trânsito , Escolha da Profissão , Quadriplegia/reabilitação , Reabilitação Vocacional/métodos , Retorno ao Trabalho , Traumatismos da Medula Espinal/reabilitação , Adulto , Humanos , Masculino , Psicometria , Quadriplegia/etiologia , Reprodutibilidade dos Testes , Traumatismos da Medula Espinal/complicações , Inquéritos e QuestionáriosRESUMO
Each year, 10 million people worldwide survive the neurologic injury associated with a stroke. Importantly, stroke survivors have more than twice the risk of subsequently developing dementia compared with people who have never had a stroke. The link between stroke and the later development of dementia is not understood. There are reports of oligoclonal bands in the CSF of stroke patients, suggesting that in some people a B-lymphocyte response to stroke may occur in the CNS. Therefore, we tested the hypothesis that a B-lymphocyte response to stroke could contribute to the onset of dementia. We discovered that, in mouse models, activated B-lymphocytes infiltrate infarcted tissue in the weeks after stroke. B-lymphocytes undergo isotype switching, and IgM, IgG, and IgA antibodies are found in the neuropil adjacent to the lesion. Concurrently, mice develop delayed deficits in LTP and cognition. Genetic deficiency, and the pharmacologic ablation of B-lymphocytes using an anti-CD20 antibody, prevents the appearance of delayed cognitive deficits. Furthermore, immunostaining of human postmortem tissue revealed that a B-lymphocyte response to stroke also occurs in the brain of some people with stroke and dementia. These data suggest that some stroke patients may develop a B-lymphocyte response to stroke that contributes to dementia, and is potentially treatable with FDA-approved drugs that target B cells.
Assuntos
Subpopulações de Linfócitos B/imunologia , Demência/etiologia , Infarto da Artéria Cerebral Média/imunologia , Idoso , Animais , Estudos de Casos e Controles , Demência/imunologia , Demência/fisiopatologia , Feminino , Humanos , Imunoglobulinas/imunologia , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/fisiopatologia , Potenciação de Longa Duração , Masculino , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BLRESUMO
OBJECTIVE: To provide a clinically useful means of interpreting change for individual patients on the Quality of Life in Neurological Disorders (Neuro-QoL) adult short forms (SFs) by applying a classical test theory concept for interpreting individual change. DESIGN: Secondary analysis of existing data. SETTING: Community. PARTICIPANTS: Persons with neurologic conditions including stroke, epilepsy, amyotrophic lateral sclerosis, multiple sclerosis, and Parkinson disease residing in community settings. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Neuro-QoL SFs for Applied Cognition-General Concerns, Applied Cognition-Executive Function, Applied Cognition-Combined, Ability to Participate in Social Roles and Activities, Satisfaction With Social Roles and Activities, Positive Affect and Well-Being, Depression, Stigma, Upper Extremity Function (Fine Motor, Activities of Daily Living), Lower Extremity Function (Mobility), Anxiety, Sleep Disturbance, Fatigue, and Emotional and Behavioral Dyscontrol. We estimated conditional minimal detectable change (cMDC) indices from the pooled SEs adjusted for a 95% confidence interval using the average of the SEs for any given pair of scores multiplied by the z score, or ([SE(Score1) + SE(Score2)]/2) * (1.96) * (SQRT(2)). RESULTS: The cMDC indices are generally smallest in the midrange of all scales, ranging from 3.6 to 11.2 T-score points, and higher on the outer quartiles ranging from 3.7 to 21.6 T-score points. The lowest midrange cMDCs were for Satisfaction With Social Roles and Activities (3.6-4.7 T-score points), and the largest were for Sleep Disturbance (9.4-11.2 T-score points). CONCLUSIONS: Change indices can help clinicians and investigators identify differences for individual patients or subjects that are large enough to motivate treatment change. cMDCs can reduce misclassification of magnitudes of change that are near the margins of error across the range of the Neuro-QoL SFs.
Assuntos
Avaliação da Deficiência , Doenças do Sistema Nervoso/psicologia , Testes Psicológicos , Qualidade de Vida , Atividades Cotidianas/psicologia , Adulto , Ansiedade/diagnóstico , Ansiedade/psicologia , Cognição , Depressão/diagnóstico , Depressão/psicologia , HumanosRESUMO
Chronic hepatitis C virus (HCV) infection is a leading cause of liver related morbidity and mortality. In many countries, there is a lack of comprehensive epidemiological data that are crucial in implementing disease control measures as new treatment options become available. Published literature, unpublished data and expert consensus were used to determine key parameters, including prevalence, viremia, genotype and the number of patients diagnosed and treated. In this study of 15 countries, viremic prevalence ranged from 0.13% in the Netherlands to 2.91% in Russia. The largest viremic populations were in India (8 666 000 cases) and Russia (4 162 000 cases). In most countries, males had a higher rate of infections, likely due to higher rates of injection drug use (IDU). Estimates characterizing the infected population are critical to focus screening and treatment efforts as new therapeutic options become available.