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Major depressive disorder (MDD) is associated with Alzheimer's disease (AD) but the precise mechanisms underlying this relationship are not understood. While it is well established that cerebrospinal fluid (CSF) soluble levels of triggering receptor expressed on myeloid cells 2 (sTREM2) increase during early stages of AD, how sTREM2 levels behave in subjects with MDD is not known. In a longitudinal study, we measured CSF sTREM2 levels in 27 elderly cognitively intact individuals with late-life major depression (LLMD) and in 19 healthy controls. We tested the hypothesis that, similarly to what happens in early stages of AD, CSF sTREM2 would be elevated in MDD. In addition, we compared the associations of CSF sTREM2, pro- and anti- inflammatory, and AD biomarkers in LLMD and control subjects. Surprisingly, we found that mean CSF sTREM2 levels were significantly reduced in LLMD compared to controls. This reduction was no longer significant at the 3-year follow-up visit when depression severity improved. In addition, we found that CSF sTREM2 was associated with AD biomarkers and proinflammatory cytokines in controls but not in LLMD. These findings suggest that impaired microglia phagocytic response to AD pathology may be a novel link between MDD and AD.
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Doença de Alzheimer , Biomarcadores , Transtorno Depressivo Maior , Glicoproteínas de Membrana , Microglia , Receptores Imunológicos , Humanos , Transtorno Depressivo Maior/metabolismo , Transtorno Depressivo Maior/líquido cefalorraquidiano , Masculino , Microglia/metabolismo , Feminino , Idoso , Receptores Imunológicos/metabolismo , Glicoproteínas de Membrana/líquido cefalorraquidiano , Glicoproteínas de Membrana/metabolismo , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/metabolismo , Biomarcadores/líquido cefalorraquidiano , Estudos Longitudinais , Fagocitose/fisiologia , Citocinas/metabolismo , Citocinas/líquido cefalorraquidiano , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Inflamação/metabolismo , Inflamação/líquido cefalorraquidianoRESUMO
BACKGROUND: An elevated neutrophil-lymphocyte ratio (NLR) in blood has been associated with Alzheimer's disease (AD). However, an elevated NLR has also been implicated in many other conditions that are risk factors for AD, prompting investigation into whether the NLR is directly linked with AD pathology or a result of underlying comorbidities. Herein, we explored the relationship between the NLR and AD biomarkers in the cerebrospinal fluid (CSF) of cognitively unimpaired (CU) subjects. Adjusting for sociodemographics, APOE4, and common comorbidities, we investigated these associations in two cohorts: the Alzheimer's Disease Neuroimaging Initiative (ADNI) and the M.J. de Leon CSF repository at NYU. Specifically, we examined associations between the NLR and cross-sectional measures of amyloid-ß42 (Aß42), total tau (t-tau), and phosphorylated tau181 (p-tau), as well as the trajectories of these CSF measures obtained longitudinally. RESULTS: A total of 111 ADNI and 190 NYU participants classified as CU with available NLR, CSF, and covariate data were included. Compared to NYU, ADNI participants were older (73.79 vs. 61.53, p < 0.001), had a higher proportion of males (49.5% vs. 36.8%, p = 0.042), higher BMIs (27.94 vs. 25.79, p < 0.001), higher prevalence of hypertensive history (47.7% vs. 16.3%, p < 0.001), and a greater percentage of Aß-positivity (34.2% vs. 20.0%, p = 0.009). In the ADNI cohort, we found cross-sectional associations between the NLR and CSF Aß42 (ß = -12.193, p = 0.021), but not t-tau or p-tau. In the NYU cohort, we found cross-sectional associations between the NLR and CSF t-tau (ß = 26.812, p = 0.019) and p-tau (ß = 3.441, p = 0.015), but not Aß42. In the NYU cohort alone, subjects classified as Aß + (n = 38) displayed a stronger association between the NLR and t-tau (ß = 100.476, p = 0.037) compared to Aß- subjects or the non-stratified cohort. In both cohorts, the same associations observed in the cross-sectional analyses were observed after incorporating longitudinal CSF data. CONCLUSIONS: We report associations between the NLR and Aß42 in the older ADNI cohort, and between the NLR and t-tau and p-tau in the younger NYU cohort. Associations persisted after adjusting for comorbidities, suggesting a direct link between the NLR and AD. However, changes in associations between the NLR and specific AD biomarkers may occur as part of immunosenescence.
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INTRODUCTION: The use of antidepressants in major depressive disorder (MDD) has been reported to influence long-term risk of Alzheimer's disease (AD) and AD-related dementias (AD/ADRD), but studies are conflicting. METHODS: We used inverse probability weighted (IPW) Cox models with time-varying covariates in a retrospective cohort study among midlife veterans with MDD within the US Veterans Affairs healthcare system from January 1, 2000 to June 1, 2022. RESULTS: A total of 35,200 patients with MDD were identified. No associations were seen regarding the effect of being exposed to any antidepressant versus no exposure on AD/ADRD risk (events = 1,056, hazard ratio = 0.94, 95% confidence interval: 0.81 to 1.09) or the exposure to specific antidepressant classes versus no exposure. A risk reduction was observed for female patients in a stratified analysis; however, the number of cases was small. DISCUSSION: Our study suggests that antidepressant exposure has no effect on AD/ADRD risk. The association in female patients should be interpreted with caution and requires further attention. HIGHLIGHTS: We studied whether antidepressant use was associated with future dementia risk. We specifically focused on patients after their first-ever diagnosis of depression. We used IPW Cox models with time-varying covariates and a large observation window. Our study did not identify an effect of antidepressant use on dementia risk. A risk reduction was observed in female patients, but the number of cases was small.
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Antidepressivos , Demência , Transtorno Depressivo Maior , Veteranos , Humanos , Feminino , Estudos Retrospectivos , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/epidemiologia , Masculino , Pessoa de Meia-Idade , Veteranos/estatística & dados numéricos , Antidepressivos/uso terapêutico , Antidepressivos/efeitos adversos , Estados Unidos/epidemiologia , Demência/epidemiologia , Modelos de Riscos Proporcionais , Fatores de Risco , IdosoRESUMO
Rationale: Determining whether an individual has obstructive or central sleep apnea is fundamental to selecting the appropriate treatment. Objectives: Here we derive an automated breath-by-breath probability of obstruction, as a surrogate of gold-standard upper airway resistance, using hallmarks of upper airway obstruction visible on clinical sleep studies. Methods: From five nocturnal polysomnography signals (airflow, thoracic and abdominal effort, oxygen saturation, and snore), nine features were extracted and weighted to derive the breath-by-breath probability of obstruction (Pobs). A development and initial test set of 29 subjects (development = 6, test = 23) (New York, NY) and a second test set of 39 subjects (Solingen, Germany), both with esophageal manometry, were used to develop Pobs and validate it against gold-standard upper airway resistance. A separate dataset of 114 subjects with 2 consecutive nocturnal polysomnographies (New York, NY) without esophageal manometry was used to assess the night-to-night variability of Pobs. Measurements and Main Results: A total of 1,962,229 breaths were analyzed. On a breath-by-breath level, Pobs was strongly correlated with normalized upper airway resistance in both test sets (set 1: cubic adjusted [adj.] R2 = 0.87, P < 0.001, area under the receiver operating characteristic curve = 0.74; set 2: cubic adj. R2 = 0.83, P < 0.001, area under the receiver operating characteristic curve = 0.7). On a subject level, median Pobs was associated with the median normalized upper airway resistance (set 1: linear adj. R2 = 0.59, P < 0.001; set 2: linear adj. R2 = 0.45, P < 0.001). Median Pobs exhibited low night-to-night variability [intraclass correlation(2, 1) = 0.93]. Conclusions: Using nearly 2 million breaths from 182 subjects, we show that breath-by-breath probability of obstruction can reliably predict the overall burden of obstructed breaths in individual subjects and can aid in determining the type of sleep apnea.
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Regras de Decisão Clínica , Polissonografia , Apneia do Sono Tipo Central/diagnóstico , Apneia Obstrutiva do Sono/diagnóstico , Adulto , Idoso , Resistência das Vias Respiratórias , Diagnóstico Diferencial , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Curva ROC , Reprodutibilidade dos Testes , Apneia do Sono Tipo Central/fisiopatologia , Apneia Obstrutiva do Sono/fisiopatologiaRESUMO
INTRODUCTION: Tumor necrosis factor (TNF) inhibitors are widely used to treat rheumatoid arthritis (RA) and their potential to retard Alzheimer's disease (AD) progression has been reported. However, their long-term effects on the dementia/AD risk remain unknown. METHODS: A propensity scored matched retrospective cohort study was conducted among 40,207 patients with RA within the US Veterans Affairs health-care system from 2000 to 2020. RESULTS: A total of 2510 patients with RA prescribed TNF inhibitors were 1:2 matched to control patients. TNF inhibitor use was associated with reduced dementia risk (hazard ratio [HR]: 0.64, 95% confidence interval [CI]: 0.52-0.80), which was consistent as the study period increased from 5 to 20 years after RA diagnosis. TNF inhibitor use also showed a long-term effect in reducing the risk of AD (HR: 0.57, 95% CI: 0.39-0.83) during the 20 years of follow-up. CONCLUSION: TNF inhibitor use is associated with lower long-term risk of dementia/AD among US veterans with RA.
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Antirreumáticos , Artrite Reumatoide , Demência , Veteranos , Antirreumáticos/efeitos adversos , Artrite Reumatoide/complicações , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/epidemiologia , Demência/induzido quimicamente , Demência/epidemiologia , Demência/prevenção & controle , Humanos , Pontuação de Propensão , Estudos Retrospectivos , Inibidores do Fator de Necrose TumoralRESUMO
We examined the relative contribution of pulmonary diseases (chronic obstructive pulmonary disease, asthma and sleep apnea) to mortality risks associated with Coronavirus Disease (COVID-19) independent of other medical conditions, health risks, and sociodemographic factors. Data were derived from a large US-based case series of patients with COVID-19, captured from a quaternary academic health network covering New York City and Long Island. From March 2 to May 24, 2020, 11,512 patients who were hospitalized were tested for COVID-19, with 4,446 (38.62%) receiving a positive diagnosis for COVID-19. Among those who tested positive, 959 (21.57%) died of COVID-19-related complications at the hospital. Multivariate-adjusted Cox proportional hazards modeling showed mortality risks were strongly associated with greater age (HR = 1.05; 95% CI: 1.04-1.05), ethnic minority (Asians, Non-Hispanic blacks, and Hispanics) (HR = 1.26; 95% CI, 1.10-1.44), low household income (HR = 1.29; 95% CI: 1.11, 1.49), and male sex (HR = 0.85; 95% CI: 0.74, 0.97). Higher mortality risks were also associated with a history of COPD (HR = 1.27; 95% CI: 1.02-1.58), obesity (HR = 1.19; 95% CI: 1.04-1.37), and peripheral artery disease (HR = 1.33; 95% CI: 1.05-1.69). Findings indicate patients with COPD had the highest odds of COVID-19 mortality compared with patients with pre-existing metabolic conditions, such as obesity, diabetes and hypertension. Sociodemographic factors including increased age, male sex, low household income, ethnic minority status were also independently associated with greater mortality risks.
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Asma/complicações , COVID-19/mortalidade , Mortalidade Hospitalar , Doença Pulmonar Obstrutiva Crônica/complicações , Síndromes da Apneia do Sono/complicações , Saúde da População Urbana/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/complicações , COVID-19/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Modelos de Riscos Proporcionais , Fatores de Risco , Fatores SocioeconômicosRESUMO
BACKGROUND AND PURPOSE: Translational research is beginning to reveal the importance of trophic factors as a therapy for cellular brain repair. The purpose of this study was to analyze whether brain-derived neurotrophic factor (BDNF) administration could mediate oligodendrogenesis and remyelination after white matter injury in subcortical stroke. METHODS: Ischemia was induced in rats by injection of endothelin-1. At 24 hours, 0.4 µg/kg of BDNF or saline was intravenously administered to the treatment and control groups, respectively. Functional evaluation, MRI, and fiber tract integrity on tractography images were analyzed. Proliferation (KI-67) and white matter repair markers (A2B5, 2',3'-cyclic-nucleotide 3'-phosphodiesterase [CNPase], adenomatous polyposis coli [APC], platelet-derived growth factor receptor alpha [PDGFR-α], oligodendrocyte marker O4 [O4], oligodendrocyte transcription factor [Olig-2], and myelin basic protein [MBP]) were analyzed at 7 and 28 days. RESULTS: The BDNF-treated animals showed less functional deficit at 28 days after treatment than the controls (P<0.05). Although T2-MRI did not show differences in lesion size at 7 and 28 days between groups, diffusion tensor imaging tractography analysis revealed significantly better tract connectivity at 28 days in the BDNF group than in the controls (P<0.05). Increased proliferation of oligodendrocyte progenitors was observed in treated animals at 7 days (P<0.05). Finally, the levels of white matter repair markers (A2B5, CNPase, and O4 at 7 days; Olig-2 and MBP at 28 days) were higher in the BDNF group than in the controls (P<0.05). CONCLUSIONS: BDNF administration exerted better functional outcome, oligodendrogenesis, remyelination, and fiber connectivity than controls in rats subjected to subcortical damage in ischemic stroke.
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Isquemia Encefálica/patologia , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Diferenciação Celular/efeitos dos fármacos , Bainha de Mielina/efeitos dos fármacos , Oligodendroglia/efeitos dos fármacos , Acidente Vascular Cerebral/patologia , Substância Branca/efeitos dos fármacos , 2',3'-Nucleotídeo Cíclico Fosfodiesterases/efeitos dos fármacos , Proteína da Polipose Adenomatosa do Colo/efeitos dos fármacos , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Isquemia Encefálica/complicações , Imagem de Tensor de Difusão , Imageamento por Ressonância Magnética , Proteína Básica da Mielina/efeitos dos fármacos , Bainha de Mielina/patologia , Bainha de Mielina/fisiologia , Ratos , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/efeitos dos fármacos , Acidente Vascular Cerebral/etiologia , Substância Branca/patologiaRESUMO
Angiotensin type 1 receptor blockers (ARBs) have induced improved functional recovery and reduced infarct volume in experimental animal models of stroke. Clinical data have indicated a positive correlation between prestroke treatment with ARBs and reduced stroke severity and better outcomes; however, the mechanisms of these beneficial effects are not yet well understood. This study compares the protective and possible reparative effects of continuous oral treatment with olmesartan (OLM) with OLM pretreatment and withdrawal after permanent middle cerebral artery occlusion (pMCAO) in rats. Fifty-two Sprague-Dawley rats were randomly assigned to five groups: MCAO(-/OLM) (OLM 10 mg/kg/day for 14 days after infarct), MCAO(OLM/OLM) (OLM 10 mg/kg/day for 7 days before and 14 days after infarct), MCAO(OLM/-) (OLM 10 mg/kg/day for 7 days before infarct), sham, and control. We analyzed functional recovery; lesion size; cell death; expression of the pro-oxidant enzyme NADPH oxidase 4 (NOX-4); isolectin-B4; and repair markers such as glial fibrillary acidic protein, vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF). All of the OLM-treated groups showed significantly better functional scores and reduced infarct sizes and cell death compared with the control group 14 days after pMCAO. Levels of NOX-4, VEGF, and BDNF were significantly lower in the brains of the MCAO(OLM/OLM) and sham groups compared with the other groups. OLM treatment improved functional recovery and reduced lesion size and cell death after cerebral ischemia. Only the continuous administration of OLM before and after stroke reduced oxidative stress levels, with better tissue preservation, without triggering brain repair marker activation.
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Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Imidazóis/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Tetrazóis/administração & dosagem , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Modelos Animais de Doenças , Método Duplo-Cego , Esquema de Medicação , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Marcação In Situ das Extremidades Cortadas , Imageamento por Ressonância Magnética , Masculino , NADPH Oxidase 4 , NADPH Oxidases/metabolismo , Ratos , Ratos Sprague-Dawley , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Acidente Vascular Cerebral/patologia , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
BACKGROUND: Rat adipose tissue-derived-mesenchymal stem cells (rAD-MSCs) have proven to be safe in experimental animal models of stroke. However, in order to use human AD-MSCs (hAD-MSCs) as a treatment for stroke patients, a proof of concept is needed. We analyzed whether the xenogeneic hAD-MSCs were as safe and effective as allogeneic rAD-MSCs in permanent Middle Cerebral Artery Occlusion (pMCAO) in rats. METHODS: Sprague-Dawley rats were randomly divided into three groups, which were intravenously injected with xenogeneic hAD-MSCs (2 × 10(6)), allogeneic rAD-MSCs (2 × 10(6)) or saline (control) at 30 min after pMCAO. Behavior, cell implantation, lesion size and cell death were evaluated. Brain markers such as GFAP (glial fibrillary acid protein), VEGF (vascular endothelial growth factor) and SYP (synaptophysin) and tumor formation were analyzed. RESULTS: Compared to controls, recovery was significantly better at 24 h and continued to be so at 14 d after IV administration of either hAD-MSCs or rAD-MSCs. No reduction in lesion size or migration/implantation of cells in the damaged brain were observed in the treatment groups. Nevertheless, cell death was significantly reduced with respect to the control group in both treatment groups. VEGF and SYP levels were significantly higher, while those of GFAP were lower in the treated groups. At three months, there was no tumor formation. CONCLUSIONS: hAD-MSCs and rAD-MSCs were safe and without side effects or tumor formation. Both treatment groups showed equal efficacy in terms of functional recovery and decreased ischemic brain damage (cell death and glial scarring) and resulted in higher angiogenesis and synaptogenesis marker levels.
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Tecido Adiposo/citologia , Infarto Cerebral/terapia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Transplante Heterólogo , Doença Aguda , Animais , Biomarcadores/metabolismo , Morte Celular , Infarto Cerebral/complicações , Infarto Cerebral/fisiopatologia , Humanos , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Ratos Sprague-Dawley , Distribuição Tecidual , Transplante HomólogoRESUMO
BACKGROUND: After acute ischemia, the tissue that is at risk of infarction can be detected by perfusion-weighted imaging/diffusion-weighted imaging (PWI/DWI) mismatch but the time that is needed to process PWI limits its use. As DWI is highly sensitive to acute ischemic tissue damage, we hypothesized that different ADC patterns represent areas with a different potential for recovery. METHODS: In a model of permanent middle cerebral artery occlusion (pMCAO), Sprague-Dawley rats were randomly distributed to sham surgery and pMCAO. We further separated the pMCAO group according to intralesional ADC pattern (homogeneous or heterogeneous). At 24 h after ischemia induction, we analyzed lesion size, functional outcome, cell death expression, and brain protection markers including ROS enzyme NOX-4. MRI included DWI (ADC maps), DTI (tractography), and PWI (CBF, CBV and MTT). RESULTS: The lesion size was similar in pMCAO rats. Animals with a heterogeneous pattern in ADC maps showed better functional outcome in Rotarod test (p = 0.032), less expression of cell death (p = 0.014) and NOX-4 (p = 0.0063), higher intralesional CBF (p = 0.0026) and larger PWI/DWI mismatch (p = 0.007). CONCLUSIONS: In a rodent model for ischemic stroke, intralesional heterogeneity in ADC maps was related to better functional outcome in lesions of similar size and interval after pMCAO. DWI ADC maps may assist in the early identification of ischemic tissue with an increased potential for recovery as higher expression of acute protection markers, lower expression of cell death, increased PWI/DWI mismatch, and higher intralesional CBF were present in animals with a heterogeneous ADC pattern.
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Isquemia Encefálica/patologia , Imagem de Difusão por Ressonância Magnética , Infarto da Artéria Cerebral Média/patologia , Acidente Vascular Cerebral/patologia , Envelhecimento , Animais , Circulação Cerebrovascular/fisiologia , Imagem de Difusão por Ressonância Magnética/métodos , Modelos Animais de Doenças , Masculino , Imagem de Perfusão/métodos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/fisiopatologiaRESUMO
BACKGROUND: Although related, the precise mechanisms linking obstructive sleep apnea (OSA) and cardiovascular disease (CVD) are unclear. Platelets are mediators of CVD risk and thrombosis and prior studies suggested associations of OSA and platelet activity. The aim of this study is to assess the link between OSA, platelet activity, and CVD-related risk factors. METHODS AND RESULTS: We studied the association of OSA-measures and platelet aggregation in participants dually enrolled in the SHHS (Sleep Heart and Health Study) and FHS (Framingham Heart Study). We applied linear regression models with adjustment for demographic and clinical covariates and explored interactions with OSA and CVD-related factors, including age, sex, body mass index, hypertension, OSA diagnosis (apnea-hypopnea index 4%≥5), and aspirin use. Our final sample was of 482 participants (60 years [14.00], 50.4% female). No associations were observed between apnea-hypopnea index 4% and platelet aggregation in the main sample. Stratified analysis revealed an association in aspirin users (n=65) for our primary exposure (apnea-hypopnea index 4%, ß=0.523; P<0.001; n=65), and secondary exposures: hypoxic burden (ß=0.358; P<0.001), minimum saturation (ß=-0.519; P=0.026), and oxygen desaturation index 3% (ß=74.672; P=0.002). No associations were detected in nonaspirin users (n=417). CONCLUSIONS: No associations were detected between OSA and platelet aggregation in a community sample. Our finding that OSA associates with increased platelet aggregation in the aspirin group, most of whom use it for primary prevention of CVD, suggests that platelet aggregation may mediate the adverse impact of OSA on vascular health in individuals with existing CVD risk, supporting further investigation.
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Doenças Cardiovasculares , Fatores de Risco de Doenças Cardíacas , Agregação Plaquetária , Apneia Obstrutiva do Sono , Humanos , Feminino , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/epidemiologia , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/complicações , Masculino , Pessoa de Meia-Idade , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/diagnóstico , Agregação Plaquetária/efeitos dos fármacos , Idoso , Medição de Risco , Aspirina/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Fatores de RiscoRESUMO
Background: Loneliness has been declared an "epidemic" associated with negative physical, mental, and cognitive health outcomes such as increased dementia risk. Less is known about the relationship between loneliness and advanced neuroimaging correlates of Alzheimer's disease (AD). Objective: To assess whether loneliness was associated with advanced neuroimaging markers of AD using neuroimaging data from Framingham Heart Study (FHS) participants without dementia. Methods: In this cross-sectional observational analysis, we used functional connectivity MRI (fcMRI), amyloid-ß (Aß) PET, and tau PET imaging data collected between 2016 and 2019 on eligible FHS cohort participants. Loneliness was defined as feeling lonely at least one day in the past week. The primary fcMRI marker was Default Mode Network intra-network connectivity. The primary PET imaging markers were Aß deposition in precuneal and FLR (frontal, lateral parietal and lateral temporal, retrosplenial) regions, and tau deposition in the amygdala, entorhinal, and rhinal regions. Results: Of 381 participants (mean age 58 [SD 10]) who met inclusion criteria for fcMRI analysis, 5% were classified as lonely (17/381). No association was observed between loneliness status and network changes. Of 424 participants (mean age 58 [SDâ=â10]) meeting inclusion criteria for PET analyses, 5% (21/424) were lonely; no associations were observed between loneliness and either Aß or tau deposition in primary regions of interest. Conclusions: In this cross-sectional study, there were no observable associations between loneliness and select fcMRI, Aß PET, and tau PET neuroimaging markers of AD risk. These findings merit further investigation in prospective studies of community-based cohorts.
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Doença de Alzheimer , Peptídeos beta-Amiloides , Solidão , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Proteínas tau , Humanos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Doença de Alzheimer/psicologia , Masculino , Feminino , Peptídeos beta-Amiloides/metabolismo , Estudos Transversais , Proteínas tau/metabolismo , Solidão/psicologia , Pessoa de Meia-Idade , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Biomarcadores , NeuroimagemRESUMO
Background: Associations of plasma total tau levels with future risk of AD have been described. Objective: To examine the extent to which plasma tau reflects underlying AD brain pathology in cognitively healthy individuals. Methods: We examined cross-sectional associations of plasma total tau with 11C-Pittsburgh Compound-B (PiB)-PET and 18F-Flortaucipir (FTP)-PET in middle-aged participants at the community-based Framingham Heart Study. Results: Our final sample included 425 participants (mean age 57.6± 9.9, 50% F). Plasma total tau levels were positively associated with amyloid-ß deposition in the precuneus region (ß±SE, 0.11±0.05; pâ=â0.025). A positive association between plasma total tau and tau PET in the rhinal cortex was suggested in participants with higher amyloid-PET burden and in APOEÉ4 carriers. Conclusions: Our study highlights that plasma total tau is a marker of amyloid deposition as early as in middle-age.
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Tomografia por Emissão de Pósitrons , Proteínas tau , Humanos , Proteínas tau/sangue , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Transversais , Idoso , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/metabolismo , Tiazóis , Compostos de Anilina , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Biomarcadores/sangue , CarbolinasRESUMO
High-resolution whole slide image scans of histopathology slides have been widely used in recent years for prediction in cancer. However, in some cases, clinical informatics practitioners may only have access to low-resolution snapshots of histopathology slides, not high-resolution scans. We evaluated strategies for training neural network prognostic models in non-small cell lung cancer (NSCLC) based on low-resolution snapshots, using data from the Veterans Affairs Precision Oncology Data Repository. We compared strategies without transfer learning, with transfer learning from general domain images, and with transfer learning from publicly available high-resolution histopathology scans. We found transfer learning from high-resolution scans achieved significantly better performance than other strategies. Our contribution provides a foundation for future development of prognostic models in NSCLC that incorporate data from low-resolution pathology slide snapshots alongside known clinical predictors.
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Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Informática Médica , Humanos , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Medicina de Precisão , Aprendizado de MáquinaRESUMO
Background: An elevated neutrophil-lymphocyte ratio (NLR) in blood has been associated with Alzheimer's disease (AD). However, an elevated NLR has also been implicated in many other conditions that are risk factors for AD, prompting investigation into whether the NLR is directly linked with AD pathology or a result of underlying comorbidities. Herein, we explored the relationship between the NLR and AD biomarkers in the cerebrospinal fluid (CSF) of cognitively unimpaired (CU) subjects. Adjusting for sociodemographics, APOE4, and common comorbidities, we investigated these associations in two cohorts: the Alzheimer's Disease Neuroimaging Initiative (ADNI) and the M.J. de Leon CSF repository at NYU. Specifically, we examined associations between the NLR and cross-sectional measures of amyloid-ß42 (Aß42), total tau (t-tau), and phosphorylated tau181 (p-tau), as well as the trajectories of these CSF measures obtained longitudinally. Results: A total of 111 ADNI and 190 NYU participants classified as CU with available NLR, CSF, and covariate data were included. Compared to NYU, ADNI participants were older (73.79 vs. 61.53, p < 0.001), had a higher proportion of males (49.5% vs. 36.8%, p = 0.042), higher BMIs (27.94 vs. 25.79, p < 0.001), higher prevalence of hypertensive history (47.7% vs. 16.3%, p < 0.001), and a greater percentage of Aß-positivity (34.2% vs. 20.0%, p = 0.009). In the ADNI cohort, we found cross-sectional associations between the NLR and CSF Aß42 (ß=-12.193, p = 0.021), but not t-tau or p-tau. In the NYU cohort, we found cross-sectional associations between the NLR and CSF t-tau (ß = 26.812, p = 0.019) and p-tau (ß = 3.441, p = 0.015), but not Aß42. In the NYU cohort alone, subjects classified as Aß+ (n = 38) displayed a stronger association between the NLR and t-tau (ß = 100.476, p = 0.037) compared to Aß- subjects or the non-stratified cohort. In both cohorts, the same associations observed in the cross-sectional analyses were observed after incorporating longitudinal CSF data. Conclusions: We report associations between the NLR and Aß42 in the older ADNI cohort, and between the NLR and t-tau and p-tau181 in the younger NYU cohort. Associations persisted after adjusting for comorbidities, suggesting a direct link between the NLR and AD. However, changes in associations between the NLR and specific AD biomarkers may occur as part of immunosenescence.
RESUMO
Blepharoptosis is a recognized cause of reversible vision loss and a non-specific indicator of neurological issues, occasionally heralding life-threatening conditions. Currently, diagnosis relies on human expertise and eyelid examination, with most existing Artificial Intelligence algorithms focusing on eyelid positioning under specialized settings. This study introduces a deep learning model with convolutional neural networks to detect blepharoptosis in more realistic conditions. Our model was trained and tested using high quality periocular images from patients with blepharoptosis as well as those with other eyelid conditions. The model achieved an area under the receiver operating characteristic curve of 0.918. For validation, we compared the model's performance against nine medical experts-oculoplastic surgeons, general ophthalmologists, and general practitioners-with varied expertise. When tested on a new dataset with varied image quality, the model's performance remained statistically comparable to that of human graders. Our findings underscore the potential to enhance telemedicine services for blepharoptosis detection.
Assuntos
Inteligência Artificial , Blefaroptose , Humanos , Blefaroptose/diagnóstico , Redes Neurais de Computação , Algoritmos , Curva ROCRESUMO
Brain repair involves a compendium of natural mechanisms that are activated following stroke. From a therapeutic viewpoint, reparative therapies that encourage cerebral plasticity are needed. In the last years, it has been demonstrated that modulatory treatments for brain repair such as trophic factor- and stem cell-based therapies can promote neurogenesis, gliogenesis, oligodendrogenesis, synaptogenesis and angiogenesis, all of which having a beneficial impact on infarct volume, cell death and, finally, and most importantly, on the functional recovery. However, even when promising results have been obtained in a wide range of experimental animal models and conditions these preliminary results have not yet demonstrated their clinical efficacy. Here, we focus on brain repair modulatory treatments for ischaemic stroke, that use trophic factors, drugs with trophic effects and stem cell therapy. Important and still unanswered questions for translational research ranging from experimental animal models to recent and ongoing clinical trials are reviewed here.
Assuntos
Isquemia Encefálica/terapia , Encéfalo/patologia , Transplante de Células-Tronco , Acidente Vascular Cerebral/terapia , Animais , Isquemia Encefálica/patologia , Ensaios Clínicos como Assunto , Modelos Animais de Doenças , Humanos , Fatores de Crescimento Neural/fisiologia , Neurogênese , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/patologia , Pesquisa Translacional BiomédicaRESUMO
BACKGROUND: The balance between T helper cells Th2- and Th1-related cytokines plays a key role in multiple sclerosis (MS). A shift from a Th1 towards a Th2 cytokine profile could have a beneficial effect on the clinical course of the disease. The objective of this study was to assess Th2/Th1 cytokine profile in relapsing-remitting MS (RRMS) patients receiving an immunosuppressive treatment with natalizumab (NAT), or an immunomodulatory treatment with glatiramer acetate (GA) after one year of treatment. METHODS: This was an observational cross-sectional study. All consecutive patients diagnosed with RRMS who had received GA or NAT for 12 months were included in the study. We determined serum levels of Th1 and Th2 cytokines (interleukin [IL]-1a, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-13, monocyte chemotactic protein [MCP]-1, tumor-necrosis factor [TNF]-α, interferon [IFN]-γ and granulocyte macrophage colony stimulating factor [GM-CSF]) by flow cytometry. Th2/Th1 bias was defined based on the ratio of IL-4, IL-5, IL-6 or IL-10 Th2 cytokines and proinflammatory INF-γ or TNF-α Th1 cytokines. RESULTS: Eleven patients under treatment with NAT and 12 patients treated with GA were evaluated. RRMS patients treated with NAT showed significantly higher levels of IL-6 (p < 0.05), MCP-1 (p < 0.01), and GM-CSF (p < 0.05) compared to GA patients after one year of treatment. A trend for increasing of IL-12p70, IL-1b, TNF- α and IFN- γ levels was also found in patients receiving NAT compared to GA patients. IL-4/IFN-γ, IFN-γ/TNF-α and IL-10/IFN-γ ratios as markers of Th2/Th1 ratio were significantly elevated in GA patients compared to those receiving NAT (p < 0.05). CONCLUSION: In conclusion, our findings suggest that GA promotes a superior Th2-biased anti-inflammatory response as compared with NAT in the systemic circulation of RRMS patients. Future studies with larger cohorts will determine whether this immune Th2 shift in GA patients is associated with a beneficial effect on disease outcome.
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Anticorpos Monoclonais Humanizados/uso terapêutico , Citocinas/sangue , Citocinas/imunologia , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/imunologia , Peptídeos/uso terapêutico , Equilíbrio Th1-Th2/efeitos dos fármacos , Adjuvantes Imunológicos/uso terapêutico , Adulto , Acetato de Glatiramer , Humanos , Masculino , Esclerose Múltipla/sangue , Natalizumab , Prevenção Secundária , Resultado do TratamentoRESUMO
BACKGROUND: Evaluating the risk of Alzheimer's disease (AD) in cognitively normal (CN) and patients with mild cognitive impairment (MCI) is extremely important. While MCI-to-AD progression risk has been studied extensively, few studies estimate CN-to-MCI conversion risk. The Cox proportional hazards (PH), a widely used survival analysis model, assumes a linear predictor-risk relationship. Generalizing the PH model to more complex predictor-risk relationships may increase risk estimation accuracy. OBJECTIVE: The aim of this study was to develop a PH model using an Xgboost regressor, based on demographic, genetic, neuropsychiatric, and neuroimaging predictors to estimate risk of AD in patients with MCI, and the risk of MCI in CN subjects. METHODS: We replaced the Cox PH linear model with an Xgboost regressor to capture complex interactions between predictors, and non-linear predictor-risk associations. We endeavored to limit model inputs to noninvasive and more widely available predictors in order to facilitate future applicability in a wider setting. RESULTS: In MCI-to-AD (nâ=â882), the Xgboost model achieved a concordance index (C-index) of 84.5%. When the model was used for MCI risk prediction in CN (nâ=â100) individuals, the C-index was 73.3%. In both applications, the C-index was statistically significantly higher in the Xgboost in comparison to the Cox PH model. CONCLUSION: Using non-linear regressors such as Xgboost improves AD dementia risk assessment in CN and MCI. It is possible to achieve reasonable risk stratification using predictors that are relatively low-cost in terms of time, invasiveness, and availability. Future strategies for improving AD dementia risk estimation are discussed.
Assuntos
Doença de Alzheimer/diagnóstico , Disfunção Cognitiva/diagnóstico , Modelos de Riscos Proporcionais , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/genética , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/genética , Progressão da Doença , Feminino , Testes Genéticos/métodos , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Prognóstico , Medição de Risco/métodos , Análise de SobrevidaRESUMO
Depressed individuals are twice as likely to develop Alzheimer's disease (AD) as compared to controls. Brain amyloid-ß (Aß) deposition is believed to have a major role in AD pathogenesis but studies also suggest associations of Aß dynamics and depression. The aim of this study was to test if plasma Aß levels are longitudinally associated to late-life depression. We measured plasma levels of amyloid-ß1-40 (Aß40) and amyloid-ß1-42 (Aß42) peptides longitudinally for three consecutive years in 48 cognitively intact elderly subjects with late-life major depressive disorder (LLMD) and 45 age-matched cognitively healthy controls. We found that the Aß42/Aß40 plasma ratio was significantly and steadily lower in depressed subjects compared to controls (p < 0.001). At screening, Aß42/Aß40 plasma did not correlate with depression severity (as measured with Hamilton Depression Scale) or cognitive performance (as measured with Mini-Mental State Examination) but was associated to depression severity at 3 years after adjustment for age, education, cognitive performance, and antidepressants use. This study showed that reduced plasma Aß42/Aß40 ratio is consistently associated with LLMD diagnosis and that increased severity of depression at baseline predicted low Aß42/Aß40 ratio at 3 years. Future studies are needed to confirm these findings and examine if the consistently lower plasma Aß42/Aß40 ratio in LLMD reflects increased brain amyloid deposition, as observed in AD subjects, and an increased risk for progressive cognitive decline and AD.