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Background: Chronic illness diagnosis while living in low resourced communities creates ongoing adversity in the process of adaptation. Resilience is an important phenomenon of study to improve health outcomes. The subject in this particular population has been poorly studied. Objective: To conceptualize resilience of individuals with chronic illness who reside in low resource communities. Design: Concept analysis. Data sources: Seminal works and current studies were searched in PubMed (including Medline), Science Direct, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), ProQuest, Google Scholar, OVID, Ebsco, and the Cochrane Database. Qualitative and quantitative studies that investigated individual resilience of adults in the setting of chronic illness who reside in low resource communities were included. Exclusions included children with chronic illness and resilience of communities and populations. Methods: Walker and Avant's method of concept analysis was utilized. The key elements for conceptualizing resilience in the setting of chronic illness who reside in low resource communities included defining attributes, antecedents and consequences of resilience identified from the literature search. Results: Analysis revealed three defining attributes: (1) reflection, contemplation, and the will to live despite adversity through hope; (2) personal transcendence through action; and (3) continuous personal transcendence and maintenance. Antecedents and consequences of resilience in the setting of chronic illness who reside in low resource communities were described and outlined. Conclusions: The conceptualization of resilience in the setting of chronic illness who reside in low resource communities is based on the defining attributes, antecedents, and consequences that resulted in a preliminary conceptual model. The model can be further tested in diverse populations to add to the existing knowledge on the subject, and develop interventions to foster resilience aimed to improve health outcomes and quality of life.
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Acetylcholine is a robust neuromodulator of the limbic system and a critical regulator of arousal and emotions. The anterior cingulate cortex (ACC) and the amygdala (AMY) are key limbic structures that are both densely innervated by cholinergic afferents and interact with each other for emotional regulation. The ACC is composed of functionally distinct dorsal (A24), rostral (A32), and ventral (A25) areas that differ in their connections with the AMY. The structural substrates of cholinergic modulation of distinct ACC microcircuits and outputs to AMY are thought to depend on the laminar and subcellular localization of cholinergic receptors. The present study examines the distribution of muscarinic acetylcholine receptors, m1 and m2, on distinct excitatory and inhibitory neurons and on AMY-targeting projection neurons within ACC areas, via immunohistochemistry and injections of neural tracers into the basolateral AMY in adult rhesus monkeys of both sexes. We found that laminar densities of m1+ and m2+ expressing excitatory and inhibitory neurons depended on area and cell type. Among the ACC areas, ventral subgenual ACC A25 exhibited greater m2+ localization on presynaptic inhibitory axon terminals and greater density of m1+ and m2+ expressing AMY-targeting (tracer+) pyramidal neurons. These patterns suggest robust cholinergic disinhibition and potentiation of amygdalar outputs from the limbic ventral ACC, which may be linked to the hyperexcitability of this subgenual ACC area in depression. These findings reveal the anatomical substrate of diverse cholinergic modulation of specific ACC microcircuits and amygdalar outputs that mediate cognitive-emotional integration and dysfunctions underlying stress and affective disorders.
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Giro del Cíngulo , Macaca mulatta , Animales , Giro del Cíngulo/metabolismo , Giro del Cíngulo/fisiología , Masculino , Femenino , Receptor Muscarínico M2/metabolismo , Receptor Muscarínico M1/metabolismo , Red Nerviosa/metabolismo , Red Nerviosa/fisiología , Acetilcolina/metabolismo , Vías Nerviosas/fisiología , Vías Nerviosas/metabolismo , Neuronas/metabolismo , Neuronas/fisiologíaRESUMEN
Cognitive impairment in learning, memory, and executive function occurs in normal aging even in the absence of Alzheimer's disease (AD). While neurons do not degenerate in humans or monkeys free of AD, there are structural changes including synapse loss and dendritic atrophy, especially in the dorsolateral prefrontal cortex (dlPFC), and these correlate with cognitive age-related impairment. Developmental studies revealed activity-dependent neuronal properties that lead to synapse remodeling by microglia. Microglia-mediated phagocytosis that may eliminate synapses is regulated by immune "eat me" and "don't eat me" signaling proteins in an activity-dependent manner, so that less active synapses are eliminated. Whether this process contributes to age-related synapse loss remains unknown. The present study used a rhesus monkey model of normal aging to investigate the balance between the "eat me" signal, complement component C1q, and the "don't eat me" signal, transmembrane glycoprotein CD47, relative to age-related synapse loss in dlPFC Area 46. Results showed an age-related elevation of C1q and reduction of CD47 at PSD95+ synapses that is associated with cognitive impairment. Additionally, reduced neuronal CD47 RNA expression was found, indicating that aged neurons were less able to produce the protective signal CD47. Interestingly, microglia do not show the hypertrophic morphology indicative of phagocytic activity. These findings suggest that in the aging brain, changes in the balance of immunologic proteins give microglia instructions favoring synapse elimination of less active synapses, but this may occur by a process other than classic phagocytosis such as trogocytosis.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Anciano , Microglía , Complemento C1q/genética , Complemento C1q/metabolismo , Antígeno CD47/metabolismo , Encéfalo/metabolismo , Disfunción Cognitiva/metabolismo , Enfermedad de Alzheimer/metabolismo , Sinapsis/metabolismoRESUMEN
The application of artificial intelligence (AI) to summarize a whole-brain magnetic resonance image (MRI) into an effective "brain age" metric can provide a holistic, individualized, and objective view of how the brain interacts with various factors (e.g., genetics and lifestyle) during aging. Brain age predictions using deep learning (DL) have been widely used to quantify the developmental status of human brains, but their wider application to serve biomedical purposes is under criticism for requiring large samples and complicated interpretability. Animal models, i.e., rhesus monkeys, have offered a unique lens to understand the human brain - being a species in which aging patterns are similar, for which environmental and lifestyle factors are more readily controlled. However, applying DL methods in animal models suffers from data insufficiency as the availability of animal brain MRIs is limited compared to many thousands of human MRIs. We showed that transfer learning can mitigate the sample size problem, where transferring the pre-trained AI models from 8,859 human brain MRIs improved monkey brain age estimation accuracy and stability. The highest accuracy and stability occurred when transferring the 3D ResNet [mean absolute error (MAE) = 1.83 years] and the 2D global-local transformer (MAE = 1.92 years) models. Our models identified the frontal white matter as the most important feature for monkey brain age predictions, which is consistent with previous histological findings. This first DL-based, anatomically interpretable, and adaptive brain age estimator could broaden the application of AI techniques to various animal or disease samples and widen opportunities for research in non-human primate brains across the lifespan.
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Students are less likely to hear and understand teacher-delivered directions or instructions when they are attending to other activities (e.g., a classmate, a previously assigned task). A classroom management system known as the Color Wheel System includes rules and transition procedures designed to increase the probability that students stop their current activities and attend to teachers as they deliver directions or instructions for the next activity. A withdrawal design was used to evaluate the effects of the Color Wheel System on a teacher's repeated directions in a first-grade general-education classroom. Results showed large and immediate decreases in teacher repeated directions both times the Color Wheel System was applied and an immediate increase when it was withdrawn. Discussion focuses on limitations and directions for future longitudinal research evaluating the effects of the Color Wheel System on uninterrupted teaching and learning time, classroom climates, student-teacher relationships, and compliance. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
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Understanding the microglial neuro-immune interactions in the primate brain is vital to developing therapeutics for cortical injury, such as stroke or traumatic brain injury. Our previous work showed that mesenchymal-derived extracellular vesicles (MSC-EVs) enhanced motor recovery in aged rhesus monkeys following injury of primary motor cortex (M1), by promoting homeostatic ramified microglia, reducing injury-related neuronal hyperexcitability, and enhancing synaptic plasticity in perilesional cortices. A focal lesion was induced via surgical ablation of pial blood vessels over lying the cortical hand representation of M1 of aged female rhesus monkeys, that received intravenous infusions of either vehicle (veh) or EVs 24 h and again 14 days post-injury. The current study used this same cohort to address how these injury- and recovery-associated changes relate to structural and molecular interactions between microglia and neuronal synapses. Using multi-labeling immunohistochemistry, high-resolution microscopy, and gene expression analysis, we quantified co-expression of synaptic markers (VGLUTs, GLURs, VGAT, GABARs), microglia markers (Iba1, P2RY12), and C1q, a complement pathway protein for microglia-mediated synapse phagocytosis, in perilesional M1 and premotor cortices (PMC). We compared this lesion cohort to age-matched non-lesion controls (ctr). Our findings revealed a lesion-related loss of excitatory synapses in perilesional areas, which was ameliorated by EV treatment. Further, we found region-dependent effects of EVs on microglia and C1q expression. In perilesional M1, EV treatment and enhanced functional recovery were associated with increased expression of C1q + hypertrophic microglia, which are thought to have a role in debris-clearance and anti-inflammatory functions. In PMC, EV treatment was associated with decreased C1q + synaptic tagging and microglia-spine contacts. Our results suggest that EV treatment may enhance synaptic plasticity via clearance of acute damage in perilesional M1, and thereby preventing chronic inflammation and excessive synaptic loss in PMC. These mechanisms may act to preserve synaptic cortical motor networks and a balanced normative M1/PMC synaptic function to support functional recovery after injury.
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Vesículas Extracelulares , Microglía , Femenino , Animales , Macaca mulatta , Complemento C1q , Recuperación de la FunciónRESUMEN
Introduction: Strong links can be made between chronic illness, low-resource communities, and poor health outcomes. One such area is the Mississippi Delta within the United States that has identified its residents rank the lowest in overall health indicators with high rates of chronic illness. Objective: This study aimed to explore the phenomenon of resilience in the setting of chronic illness and low resourced communities to gain baseline knowledge of the topic to improve protective resilience within the community. Methods: The descriptive phenomenological psychological reduction method outlined by Giorgi et al. was used based on semistructured and in-depth interviews with eight individuals (ages 33-64) who were recruited by purposive sampling through a humanitarian organization. Results: Six themes of the lived experience of the participants revealed the eidetic structure and essence of the experience. The results of the study provided important implications related to the meaning of chronic illness to the individual, poor resilient risk factors, antecedents to resilience, and areas to focus on for resilience promotion. Conclusion: A lifeworld perspective of the individual can help nurses develop a greater understanding in formulating interventions for resilience promotion.
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Cardiovascular disease remains a leading cause of death worldwide despite the use of available cardiovascular disease risk prediction tools. Identification of high-risk individuals via risk stratification and screening at sub-clinical stages, which may be offered by ocular screening, is important to prevent major adverse cardiac events. Retinal microvasculature has been widely researched for potential application in both diabetes and cardiovascular disease risk prediction. However, the conjunctival microvasculature as a tool for cardiovascular disease risk prediction remains largely unexplored. The purpose of this review is to evaluate the current cardiovascular risk assessment methods, identifying gaps in the literature that imaging of the ocular microcirculation may have the potential to fill. This review also explores the themes of machine learning, risk scores, biomarkers, medical imaging, and clinical risk factors. Cardiovascular risk classification varies based on the population assessed, the risk factors included, and the assessment methods. A more tailored, standardised and feasible approach to cardiovascular risk prediction that utilises technological and medical imaging advances, which may be offered by ocular imaging, is required to support cardiovascular disease prevention strategies and clinical guidelines.
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Enfermedades Cardiovasculares , Humanos , Factores de Riesgo , Enfermedades Cardiovasculares/etiología , Biomarcadores , Diagnóstico por Imagen , Factores de Riesgo de Enfermedad Cardiaca , Medición de Riesgo/métodosRESUMEN
Understanding the microglial neuro-immune interactions in the primate brain is vital to developing therapeutics for cortical injury, such as stroke. Our previous work showed that mesenchymal-derived extracellular vesicles (MSC-EVs) enhanced motor recovery in aged rhesus monkeys post-injury of primary motor cortex (M1), by promoting homeostatic ramified microglia, reducing injury-related neuronal hyperexcitability, and enhancing synaptic plasticity in perilesional cortices. The current study addresses how these injury- and recovery-associated changes relate to structural and molecular interactions between microglia and neuronal synapses. Using multi-labeling immunohistochemistry, high resolution microscopy, and gene expression analysis, we quantified co-expression of synaptic markers (VGLUTs, GLURs, VGAT, GABARs), microglia markers (Iba-1, P2RY12), and C1q, a complement pathway protein for microglia-mediated synapse phagocytosis, in perilesional M1 and premotor cortices (PMC) of monkeys with intravenous infusions of either vehicle (veh) or EVs post-injury. We compared this lesion cohort to aged-matched non-lesion controls. Our findings revealed a lesion-related loss of excitatory synapses in perilesional areas, which was ameliorated by EV treatment. Further, we found region-dependent effects of EV on microglia and C1q expression. In perilesional M1, EV treatment and enhanced functional recovery were associated with increased expression of C1q + hypertrophic microglia, which are thought to have a role in debris-clearance and anti-inflammatory functions. In PMC, EV treatment was associated with decreased C1q + synaptic tagging and microglial-spine contacts. Our results provided evidence that EV treatment facilitated synaptic plasticity by enhancing clearance of acute damage in perilesional M1, and thereby preventing chronic inflammation and excessive synaptic loss in PMC. These mechanisms may act to preserve synaptic cortical motor networks and a balanced normative M1/PMC synaptic connectivity to support functional recovery after injury.
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The purpose of this descriptive phenomenological study was to explore the lived experience and meaning of resilience of individuals in the setting of chronic illness who reside in low-resource communities of the Mississippi Delta, USA. Descriptive phenomenology and Polk's resilience theory were utilized that focused on the individual's lifeworld and the meaning of resilience. The descriptive phenomenological psychological by reduction method (DPPRM) was used for the analysis and further linked to specific aspects of resilience and Polk's resilience theory operationalized patterns. Findings revealed six themes of the lived experience of the participants that make up the eidetic structure and are linked to multidimensional aspects of resilience to create meaning. Fostering increased resilient pattern development has the potential to improve health outcomes, well-being, and quality of life across the spectrum.
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Negro o Afroamericano , Resiliencia Psicológica , Humanos , Calidad de Vida , Enfermedad CrónicaRESUMEN
[This corrects the article DOI: 10.3389/fdgth.2022.870522.].
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Both the medial temporal lobe and the dorsolateral prefrontal cortex have been implicated in learning and memory. However, it has been difficult to ascertain the degree to which the two structures are dependent on each other or interact in subserving these cognitive functions. To investigate this question directly, we prepared two group of monkeys. First, the contralateral frontal-hippocampal split group (CFHS) received a unilateral lesion of the hippocampus and surrounding posterior parahippocampal cortices (H +), combined with a contralateral lesion of the dorsolateral prefrontal cortex (DLPFC) plus transection of the corpus callosum and anterior commissure. This preparation functionally "disconnects" the remaining intact H + from the sole intact DLPFC in the opposite hemisphere. As a surgical control group, a second set of animals, the ipsilateral frontal-hippocampal split group, was prepared with a unilateral lesion of the DLPFC and an ipsilateral H + lesion together plus transection of the corpus callosum and anterior commissure. This preparation matches the locus and extent of damage in the cross-lesion group but allows the intact H + and intact DLPFC to interact ipsilaterally. Following recovery from surgery, all animals were then tested on the delayed nonmatching to sample task (DNMS), a test of recognition memory. The crossed-lesion split-brain group (CFHS) was markedly impaired on DNMS in both acquisition (rule learning) and performance over delays (recognition memory). The results provide evidence of a functionally dependent interaction between the medial temporal lobe and the dorsolateral prefrontal cortex in learning and memory. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
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Aprendizaje , Reconocimiento en Psicología , Animales , Macaca mulatta , Lóbulo Temporal , Corteza Cerebral , Hipocampo/patología , Corteza PrefrontalRESUMEN
Age-related declines in cognitive abilities occur as early as middle-age in humans and rhesus monkeys. Specifically, performance by aged individuals on tasks of executive function (EF) and working memory (WM) is characterized by greater frequency of errors, shorter memory spans, increased frequency of perseverative responses, impaired use of feedback and reduced speed of processing. However, how aging precisely differentially impacts specific aspects of these cognitive functions and the distinct brain areas mediating cognition are not well understood. The prefrontal cortex (PFC) is known to mediate EF and WM and is an area that shows a vulnerability to age-related alterations in neuronal morphology. In the current study, we show that performance on EF and WM tasks exhibited significant changes with age, and these impairments correlate with changes in biophysical properties of layer 3 (L3) pyramidal neurons in lateral LPFC (LPFC). Specifically, there was a significant age-related increase in excitability of L3 LPFC pyramidal neurons, consistent with previous studies. Further, this age-related hyperexcitability of LPFC neurons was significantly correlated with age-related decline on a task of WM, but not an EF task. The current study characterizes age-related performance on tasks of WM and EF and provides insight into the neural substrates that may underlie changes in both WM and EF with age.
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Memoria a Corto Plazo , Neuronas , Animales , Envejecimiento , Macaca mulatta , Memoria a Corto Plazo/fisiología , Corteza Prefrontal , Células Piramidales/fisiologíaRESUMEN
Down syndrome (DS), or trisomy 21, is manifested in a variety of anatomical and cellular abnormalities resulting in intellectual deficits and early onset of Alzheimer's disease (AD) with no effective treatments available to alleviate the pathologies associated with the disorder. The therapeutic potential of extracellular vesicles (EVs) has emerged recently in relation to various neurological conditions. We have previously demonstrated the therapeutic efficacy of mesenchymal stromal cell-derived EVs (MSC-EVs) in cellular and functional recovery in a rhesus monkey model of cortical injury. In the current study, we evaluated the therapeutic effect of MSC-EVs in a cortical spheroid (CS) model of DS generated from patient-derived induced pluripotent stem cells (iPSCs). Compared to euploid controls, trisomic CS display smaller size, deficient neurogenesis, and AD-related pathological features, such as enhanced cell death and depositions of amyloid beta (Aß) and hyperphosphorylated tau (p-tau). EV-treated trisomic CS demonstrated preserved size, partial rescue in the production of neurons, significantly decreased levels of Aß and p-tau, and a reduction in the extent of cell death as compared to the untreated trisomic CS. Together, these results show the efficacy of EVs in mitigating DS and AD-related cellular phenotypes and pathological depositions in human CS.
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Enfermedad de Alzheimer , Síndrome de Down , Vesículas Extracelulares , Humanos , Síndrome de Down/metabolismo , Péptidos beta-Amiloides/metabolismo , Enfermedad de Alzheimer/metabolismo , Vesículas Extracelulares/metabolismo , Neuronas/metabolismoRESUMEN
Age-related declines in cognitive abilities occur as early as middle-age in humans and rhesus monkeys. Specifically, performance by aged individuals on tasks of executive function (EF) and working memory (WM) is characterized by greater frequency of errors, shorter memory spans, increased frequency of perseverative responses, impaired use of feedback and reduced speed of processing. However, how aging precisely differentially impacts specific aspects of these cognitive functions and the distinct brain areas mediating cognition are not well understood. The prefrontal cortex (PFC) is known to mediate EF and WM and is an area that shows a vulnerability to age-related alterations in neuronal morphology. In the current study, we show that performance on EF and WM tasks exhibited significant changes with age and these impairments correlate with changes in biophysical properties of L3 pyramidal neurons in lateral LPFC (LPFC). Specifically, there was a significant age-related increase in excitability of Layer 3 LPFC pyramidal neurons, consistent with previous studies. Further, this age-related hyperexcitability of LPFC neurons was significantly correlated with age-related decline on a task of WM, but not an EF task. The current study characterizes age-related performance on tasks of WM and EF and provides insight into the neural substrates that may underlie changes in both WM and EF with age.
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OBJECTIVE: Coronary microvascular dysfunction (CMD) is a cause of ischaemia with non-obstructive coronary arteries (INOCA). It is notoriously underdiagnosed due to the need for invasive microvascular function testing. We hypothesized that systemic microvascular dysfunction could be demonstrated non-invasively in the microcirculation of the bulbar conjunctiva in patients with CMD. METHODS: Patients undergoing coronary angiography for the investigation of chest pain or dyspnoea, with physiologically insignificant epicardial disease (fractional flow reserve ≥0.80) were recruited. All patients underwent invasive coronary microvascular function testing. We compared a cohort of patients with evidence of CMD (IMR ≥25 or CFR <2.0); to a group of controls (IMR <25 and CFR ≥2.0). Conjunctival imaging was performed using a previously validated combination of a smartphone and slit-lamp biomicroscope. This technique allows measurement of vessel diameter and other indices of microvascular function by tracking erythrocyte motion. RESULTS: A total of 111 patients were included (43 CMD and 68 controls). There were no differences in baseline demographics, co-morbidities or epicardial coronary disease severity. The mean number of vessel segments analysed per patient was 21.0 ± 12.8 (3.2 ± 3.5 arterioles and 14.8 ± 10.8 venules). In the CMD cohort, significant reductions were observed in axial/cross-sectional velocity, blood flow, wall shear rate and stress. CONCLUSION: The changes in microvascular function linked to CMD can be observed non-invasively in the bulbar conjunctiva. Conjunctival vascular imaging may have utility as a non-invasive tool to both diagnose CMD and augment conventional cardiovascular risk assessment.
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Enfermedad de la Arteria Coronaria , Reserva del Flujo Fraccional Miocárdico , Isquemia Miocárdica , Humanos , Estudios Transversales , Estudios Prospectivos , Hemodinámica , Angiografía Coronaria/métodos , Vasos Coronarios , Microcirculación , Conjuntiva , Circulación CoronariaRESUMEN
BACKGROUND: Atherosclerotic heart disease often remains asymptomatic until presentation with a major adverse cardiovascular event. Primary preventive therapies improve outcomes, but conventional screening often misattributes risk. Vascular imaging can be utilised to detect atherosclerosis, but often involves ionising radiation. The conjunctiva is a readily accessible vascular network allowing non-invasive hemodynamic evaluation. AIM: To compare conjunctival microcirculatory function in patients with and without obstructive coronary artery disease. METHODS: We compared the conjunctival microcirculation of myocardial infarction patients (MI-cohort) to controls with no obstructive coronary artery disease (NO-CAD cohort). Conjunctival imaging was performed using a smartphone and slit-lamp biomicroscope combination. Microvascular indices of axial (Va) and cross-sectional (Vcs) velocity; blood flow rate (Q); and wall shear rate (WSR) were compared in all conjunctival vessels between 5 and 45 µm in diameter. RESULTS: A total of 127 patients were recruited (66 MI vs 61 NO-CAD) and 3602 conjunctival vessels analysed (2414 MI vs 1188 NO-CAD). Mean Va, Vcs and Q were significantly lower in the MI vs NO-CAD cohort (Va 0.50 ± 0.17 mm/s vs 0.55 ± 0.15 mm/s, p < 0.001; Vcs 0.35 ± 0.12 mm/s vs 0.38 ± 0.10 mm/s, p < 0.001; Q 154 ± 116 pl/s vs 198 ± 130 pl/s, p < 0.001). To correct for differences in mean vessel diameter, WSR was compared in 10-36 µm vessels (3268/3602 vessels) and was lower in the MI-cohort (134 ± 64 s-1 vs 140 ± 63 s-1, p = 0.002). CONCLUSIONS: Conjunctival microcirculatory alterations can be observed in patients with obstructive coronary artery disease. The conjunctival microvasculature merits further evaluation in cardiovascular risk screening.
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Enfermedad de la Arteria Coronaria , Humanos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Velocidad del Flujo Sanguíneo , Microcirculación/fisiología , Estudios Transversales , Conjuntiva/irrigación sanguínea , Vasos Coronarios/diagnóstico por imagen , Angiografía CoronariaRESUMEN
Age-associated cognitive decline is common among otherwise healthy elderly people, even in the absence of Alzheimer's disease and neuron loss. Instead, white matter loss and myelin damage are strongly associated with cognitive decline. Myelin is subject to lifelong oxidative stress that damages the myelin sheath, which is repaired by cells of the oligodendrocyte lineage. This process is mediated by oligodendrocyte precursor cells (OPCs) that sense the damage and respond by proliferating locally and migrating to the region, where they differentiate into mature myelinating oligodendrocytes. In aging, extensive myelin damage, in combination with inefficient remyelination, leads to chronically damaged myelin and loss of efficient neuronal conduction. This study used the rhesus monkey model of normal aging to examine how myelin regeneration capacity is affected by age. Results show that older subjects have reduced numbers of new BCAS1 + myelinating oligodendrocytes, which are newly formed cells, and that this reduction is associated with poorer cognitive performance. Interestingly, this does not result from limited proliferation of progenitor OPCs. Instead, the transcription factor NKX2.2, which regulates OPCs differentiation, is significantly decreased in aged OPCs. This suggests that these OPCs have a diminished potential for differentiation into mature oligodendrocytes. In addition, mature oligodendrocytes have reduced RNA expression of two essential myelin protein markers, MBP and PLP. These data collectively suggest that in the normal aging brain, there is a reduction in regenerative OPCs as well as myelin production that impairs the capacity for remyelination.
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Células Precursoras de Oligodendrocitos , Remielinización , Remielinización/fisiología , Vaina de Mielina/metabolismo , EncéfaloRESUMEN
Purpose: To evaluate the therapeutic benefit of a novel peptide, ALM201, in ocular pathologic vascularization. Design: Experimental study in mouse, rat, and rabbit animal models. Participants: Ten-week-old Lister Hooded male rats, 8-week-old Brown Norway male rats, 9-day-old C57BL/6J mice, and 12-month-old New Zealand male rabbits. Methods: Corneal vascularization was scored for vessel density and vessel distance to suture in a rat corneal suture model. Ocular penetration and biodistribution were evaluated by matrix-assisted laser desorption/ionization mass spectrometry imaging after topical ALM201 application to rabbit eyes. A mouse choroidal sprouting assay, with aflibercept as positive control, was used to evaluate choroidal neovascularization (CNV) in the posterior segment tissue. Efficacy of topical ALM201 was assessed using a rat laser CNV model of neovascular age-related macular degeneration. Main Outcome Measures: Clinical scoring and histologic analysis of vascularized corneas, sprouting area, lesion size, and vessel leakiness in posterior segments. Results: Assessment of ALM201 treatment in the rat corneal suture model showed a significant decrease in vessel density (P = 0.0065) and vessel distance to suture (P = 0.021) compared with vehicle control (phosphate-buffered saline [PBS]). Infiltration of inflammatory cells into the corneal stroma also was reduced significantly compared with PBS (724.5 ± 122 cells/mm2 vs. 1837 ± 195.9 cells/mm2, respectively; P = 0.0029). Biodistribution in rabbit eyes confirmed ALM201 bioavailability in anterior and posterior ocular segments 1 hour after topical instillation. ALM201 treatment significantly suppressed choroid vessel sprouting when compared with PBS treatment (44.5 ± 14.31 pixels vs. 120.9 ± 33.37 pixels, respectively; P = 0.04) and was not inferior to aflibercept (65.63 ± 11.86 pixels; P = 0.7459). Furthermore, topical ALM201 significantly improved vessel leakiness (leakage scores: 2.1 ± 0.7 vs. 2.9 ± 0.1; P = 0.0274) and lesion size (144,729 ± 33,239 µm3 vs. 187,923 ± 28,575 µm3; P = 0.03) in the rat laser CNV model when compared with topical PBS vehicle. Conclusions: ALM201 is a promising novel molecule with anti-inflammatory and antivascularization activity and is a strong candidate to meet the clinical need of a new, topically delivered therapeutic agent for treating inflammation and pathologic vascularization in the anterior and posterior segments of the eye.
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We conducted a 16-week randomized controlled trial in psychiatric outpatients with a lifetime diagnosis of a mood and/or anxiety disorder to measure the impact of a first-of-its-kind precision digital intervention software solution based on social rhythm regulation principles. The full intent-to-treat (ITT) sample consisted of 133 individuals, aged 18-65. An exploratory sub-sample of interest was those individuals who presented with moderately severe to severe depression at study entry (baseline PHQ-8 score ≥15; N = 28). Cue is a novel digital intervention platform that capitalizes on the smartphone's ability to continuously monitor depression-relevant behavior patterns and use each patient's behavioral data to provide timely, personalized "micro-interventions," making this the first example of a precision digital intervention of which we are aware. Participants were randomly allocated to receive Cue plus care-as-usual or digital monitoring only plus care as usual. Within the full study and depressed-at-entry samples, we fit a mixed effects model to test for group differences in the slope of depressive symptoms over 16 weeks. To account for the non-linear trajectory with more flexibility, we also fit a mixed effects model considering week as a categorical variable and used the resulting estimates to test the group difference in PHQ change from baseline to 16 weeks. In the full sample, the group difference in the slope of PHQ-8 was negligible (Cohen's d = -0.10); however, the Cue group demonstrated significantly greater improvement from baseline to 16 weeks (p = 0.040). In the depressed-at-entry sample, we found evidence for benefit of Cue. The group difference in the slope of PHQ-8 (Cohen's d = -0.72) indicated a meaningfully more rapid rate of improvement in the intervention group than in the control group. The Cue group also demonstrated significantly greater improvement in PHQ-8 from baseline to 16 weeks (p = 0.009). We are encouraged by the size of the intervention effect in those who were acutely ill at baseline, and by the finding that across all participants, 80% of whom were receiving pharmacotherapy, we observed significant benefit of Cue at 16 weeks of treatment. These findings suggest that a social rhythm-focused digital intervention platform may represent a useful and accessible adjunct to antidepressant treatment (https://clinicaltrials.gov/ct2/show/NCT03152864?term=ellen+frank&draw=2&rank=3).