RESUMEN
Reduced graphene oxide (rGO) has unique physicochemical properties that make it suitable for therapeutic applications in neurodegenerative scenarios. This study investigates the therapeutic potential of rGO in a cuprizone-induced demyelination model in mice through histomorphological techniques and analysis of biochemical parameters. We demonstrate that daily intraperitoneal administration of rGO (1 mg ml-1) for 21 days tends to reduce demyelination in theCorpus callosumby decreasing glial cell recruitment during the repair mechanism. Additionally, rGO interferes with oxidative stress markers in the brain and liver indicating potential neuroprotective effects in the central nervous system. No significant damage to vital organs was observed, suggesting that multiple doses could be used safely. However, further long-term investigations are needed to understand rGO distribution, metabolism, routes of action and associated challenges in central neurodegenerative therapies. Overall, these findings contribute to the comprehension of rGO effectsin vivo, paving the way for possible future clinical research.
Asunto(s)
Cuprizona , Enfermedades Desmielinizantes , Grafito , Estrés Oxidativo , Animales , Grafito/química , Enfermedades Desmielinizantes/inducido químicamente , Enfermedades Desmielinizantes/tratamiento farmacológico , Enfermedades Desmielinizantes/patología , Ratones , Estrés Oxidativo/efectos de los fármacos , Masculino , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/química , Encéfalo/patología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Hígado/efectos de los fármacos , Hígado/patología , Hígado/metabolismo , Cuerpo Calloso/efectos de los fármacos , Cuerpo Calloso/patología , Cuerpo Calloso/metabolismoRESUMEN
Though the mechanisms are not fully understood, tryptophan (Trp) and physical exercise seem to regulate mechanical hypersensitivity in fibromyalgia. Here, we tested the impact of Trp supplementation and continuous low-intensity aerobic exercise on the modulation of mechanical hypersensitivity in a fibromyalgia-like model induced by acid saline in female rats. Twelve-month-old female Wistar rats were randomly divided into groups: [control (n = 6); acid saline (n = 6); acid saline + exercise (n = 6); acid saline + Trp (n = 6); and acid saline + exercise + Trp (n = 6)]. Hypersensitivity was caused using two intramuscular jabs of acid saline (20 µL; pH 4.0; right gastrocnemius), 3 days apart. The tryptophan-supplemented diet contained 7.6 g/hg of Trp. The three-week exercise consisted of progressive (30-45 min) treadmill running at 50 to 60% intensity, five times (Monday to Friday) per week. We found that acid saline induced contralateral mechanical hypersensitivity without changing the levels of Trp, serotonin (5-HT), and kynurenine (KYN) in the brain. Hypersensitivity was reduced by exercise (~150%), Trp (~67%), and its combination (~160%). The Trp supplementation increased the levels of Trp and KYN in the brain, and the activity of indoleamine 2,3-dioxygenase (IDO), and decreased the ratio 5-HT:KYN. Exercise did not impact the assessed metabolites. Combining the treatments reduced neither hypersensitivity nor the levels of serotonin and Trp in the brain. In conclusion, mechanical hypersensitivity induced by acid saline in a fibromyalgia-like model in female rats is modulated by Trp supplementation, which increases IDO activity and leads to improved Trp metabolism via the KYN pathway. In contrast, physical exercise does not affect mechanical hypersensitivity through brain Trp metabolism via either the KYN or serotonin pathways. Because this is a short study, generalizing its findings warrants caution.
Asunto(s)
Modelos Animales de Enfermedad , Fibromialgia , Condicionamiento Físico Animal , Ratas Wistar , Serotonina , Triptófano , Animales , Triptófano/metabolismo , Triptófano/farmacología , Fibromialgia/metabolismo , Femenino , Ratas , Serotonina/metabolismo , Quinurenina/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Hiperalgesia/metabolismo , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/patología , Suplementos DietéticosRESUMEN
BACKGROUND: Leukocyte telomere length (LTL) shortens with age and may be related to multiple sclerosis (MS). OBJECTIVE: We hypothesize that chronologically young people with MS (pwMS) with short LTL behave similarly to older MS subjects. METHODS: Prospective 2-year study including two cohorts of young (18-35 years) and elderly (⩾50 years) pwMS with similar disease duration. Physical and cognitive evaluation, 3 T brain magnetic resonance imaging (MRI) and retinal nerve fiber layer (RNFL) measurement by optical coherence tomography were performed. LTL was measured by quantitative polymerase chain reaction assay. RESULTS: Around 105 patients were included, 57 young and 48 elderly. LTL was shorter in older patients (0.61 versus 0.57, p = 0.0081) and in males (female, 0.60; male, 0.59; p = 0.01335). For every 10-year increase in age, LTL was 0.02 U shorter. In elderly, LTL correlated with disease duration (p = 0.05), smoking (p = 0.03), Expanded Disability Status Scale (EDSS; p = 0.004), 9HPT (p = 0.00007), high-efficacy therapies (p = 0.001), brain lesion volume (BLV) (p = 0.011), and number of T2 lesions (p = 0.01). In young patients, LTL did not correlate with clinical or radiological variables. For every 0.1 U shorter LTL, gray matter volume decreased 1.75 cm3 and white matter volume 1.78 cm3. CONCLUSION: LTL correlated with disability and BLV in elderly. Besides LTL shortening, other variables should be considered as mechanisms of neurodegeneration that might be involved in aging pwMS.
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Esclerosis Múltiple , Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Adulto Joven , Adolescente , Anciano , Esclerosis Múltiple/diagnóstico por imagen , Esclerosis Múltiple/patología , Esclerosis Múltiple/genética , Estudios Prospectivos , Biomarcadores , Imagen por Resonancia Magnética , Telómero , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Leucocitos/patología , Tomografía de Coherencia Óptica , Acortamiento del Telómero , Envejecimiento/patologíaRESUMEN
Stroke, the second leading cause of mortality globally, predominantly results from ischemic conditions. Immediate attention and diagnosis, related to the characterization of brain lesions, play a crucial role in patient prognosis. Standard stroke protocols include an initial evaluation from a non-contrast CT to discriminate between hemorrhage and ischemia. However, non-contrast CTs lack sensitivity in detecting subtle ischemic changes in this phase. Alternatively, diffusion-weighted MRI studies provide enhanced capabilities, yet are constrained by limited availability and higher costs. Hence, we idealize new approaches that integrate ADC stroke lesion findings into CT, to enhance the analysis and accelerate stroke patient management. This study details a public challenge where scientists applied top computational strategies to delineate stroke lesions on CT scans, utilizing paired ADC information. Also, it constitutes the first effort to build a paired dataset with NCCT and ADC studies of acute ischemic stroke patients. Submitted algorithms were validated with respect to the references of two expert radiologists. The best achieved Dice score was 0.2 over a test study with 36 patient studies. Despite all the teams employing specialized deep learning tools, results reveal limitations of computational approaches to support the segmentation of small lesions with heterogeneous density.
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Accidente Cerebrovascular Isquémico , Tomografía Computarizada por Rayos X , Humanos , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Imagen por Resonancia Magnética/métodos , Algoritmos , Imagen de Difusión por Resonancia Magnética/métodos , Isquemia Encefálica/diagnóstico por imagen , Masculino , Femenino , Anciano , Procesamiento de Imagen Asistido por Computador/métodos , Aprendizaje Profundo , Accidente Cerebrovascular/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Encéfalo/patologíaRESUMEN
PURPOSE OF REVIEW: This review aims to rediscuss the leading theories concerning the role of basal ganglia and the thalamus in the genesis of aphasic symptoms in the absence of gross anatomical lesions in cortical language areas as assessed by conventional neuroimaging studies. RECENT FINDINGS: New concepts in language processing and modern neuroimaging techniques have enabled some progress in resolving the impasse between the current dominant theories: (a) direct and specific linguistic processing and (b) subcortical structures as processing relays in domain-general functions. Of particular interest are studies of connectivity based on functional magnetic resonance imaging (MRI) and tractography that highlight the impact of white matter pathway lesions on aphasia development and recovery. Connectivity studies have put into evidence the central role of the arcuate fasciculus (AF), inferior frontal occipital fasciculus (IFOF), and uncinate fasciculus (UF) in the genesis of aphasia. Regarding the thalamus, its involvement in lexical-semantic processing through modulation of the frontal cortex is becoming increasingly apparent.
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Afasia , Tálamo , Humanos , Afasia/fisiopatología , Afasia/diagnóstico por imagen , Afasia/etiología , Afasia/patología , Tálamo/diagnóstico por imagen , Tálamo/fisiopatología , Tálamo/patología , Ganglios Basales/diagnóstico por imagen , Ganglios Basales/fisiopatología , Ganglios Basales/patología , Vías Nerviosas/fisiopatología , Vías Nerviosas/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Encéfalo/fisiopatología , Imagen por Resonancia MagnéticaRESUMEN
Toxic-metabolic encephalopathies are a group of disorders in which an exogenous or endogenous substance leads to transient or permanent neuronal damage. It is an important cause of potentially reversible acute encephalopathy syndrome. The signs and symptoms of toxic encephalopathies may be relatively nonspecific, and toxicologic tests are not always widely available. Imaging plays a key role in determining the most probable diagnosis, pointing to the next steps of investigation, and providing prognostic information. In this chapter, we review the main acquired toxic-metabolic leukoencephalopathies, commenting on their pathophysiology, imaging patterns, and rationale for an adequate diagnosis in detail.
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Leucoencefalopatías , Humanos , Leucoencefalopatías/diagnóstico , Encéfalo/patología , Encéfalo/diagnóstico por imagenRESUMEN
Background: The association of moderate and severe dementia with low body mass index (BMI) is well described, but weight decline seems to also occur in individuals with preclinical neuropathologies. Considering that up to one-fifth of individuals with normal cognition meet the criteria for a dementia-related neuropathological diagnosis, autopsy studies are key to detecting preclinical neurodegenerative and cerebrovascular diseases that could be underlying weight changes. Objective: We investigated the association between dementia-related brain lesions and BMI and evaluated whether the cognitive function was a mediator of this association. Methods: In 1,170 participants, sociodemographic data, clinical history, and cognitive post-mortem evaluation were assessed with an informant. Neuropathological evaluation was performed in all cases. Linear regression models were used to investigate the association between neuropathological lesions (exposure variable) and BMI (outcome) adjusted for demographic, clinical, and cognitive variables in the whole sample, and in only those with normal cognition. Corrections for multiple comparisons were performed. In addition, a mediation analysis was performed to investigate the direct and indirect effects of cognitive abilities on the association between neuropathology and BMI. Results: Individuals with lower BMI had a higher burden of neuropathological lesions and poorer cognitive abilities. Only neurofibrillary tangles (NFT) and neuropathological comorbidity were associated with low BMI, while other neurodegenerative and cerebrovascular lesions were not. NFT were indirectly associated with BMI through cognitive abilities, and also directly, even in participants with normal cognition. Conclusions: Neurofibrillary tangles were directly associated with low BMI even in individuals with preclinical Alzheimer's disease.
Asunto(s)
Índice de Masa Corporal , Cognición , Humanos , Femenino , Masculino , Anciano , Cognición/fisiología , Anciano de 80 o más Años , Encéfalo/patología , Ovillos Neurofibrilares/patología , Demencia/patología , Demencia/epidemiología , Pruebas Neuropsicológicas , AutopsiaRESUMEN
Due to its extensive use as a painkiller, anti-inflammatory, and immune modulatory agent, as well as its effectiveness in treating severe COVID-19, dexamethasone, a synthetic glucocorticoid, has gained attention not only for its impact on public health but also for its environmental implications. Various studies have reported its presence in aquatic environments, including urban waters, surface samples, sediments, drinking water, and wastewater effluents. However, limited information is available regarding its toxic effects on nontarget aquatic organisms. Therefore, this study aimed to investigate the mechanism of toxicity underlying dexamethasone-induced brain damage in the bioindicator Danio rerio following long-term exposure. Adult zebrafish were treated with environmentally relevant concentrations of dexamethasone (20, 40, and 60 ng L-1) for 28 days. To elucidate the possible mechanisms involved in the toxicity of the pharmaceutical compound, we conducted a behavioral test battery (Novel Tank and Light and Dark tests), oxidative stress biomarkers, acetylcholinesterase enzyme activity quantification, histopathological analysis, and gene expression analysis using qRT-PCR (p53, bcl-2, bax, caspase-3, nrf1, and nrf2).The results revealed that the pharmaceutical compound could produce anxiety-like symptoms, increase the oxidative-induced stress response, decrease the activity of acetylcholinesterase enzyme, and cause histopathological alterations, including perineuronal vacuolization, granular and molecular layers deterioration, cell swallowing and intracellular spaces. The expression of genes involved in the apoptotic process (p53, bax, and casp-3) and antioxidant defense (nrf1 and nrf2) was upregulated in response to oxidative damage, while the expression of the anti-apoptotic gene bcl-2 was down-regulated indicating that the environmental presence of dexamethasone may pose a threat to wildlife and human health.
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Apoptosis , Dexametasona , Estrés Oxidativo , Contaminantes Químicos del Agua , Pez Cebra , Animales , Estrés Oxidativo/efectos de los fármacos , Apoptosis/efectos de los fármacos , Dexametasona/toxicidad , Contaminantes Químicos del Agua/toxicidad , Glucocorticoides/toxicidad , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/patología , Lesiones Encefálicas/inducido químicamenteRESUMEN
This study investigates the efficacy of nebivolol (NBV) in experimental models of toxoplasmosis, focusing on parasite burden reduction and neuronal protection. In the acute model of experimental toxoplasmosis, Swiss mice infected with RH strain tachyzoites received oral NBV chlorhydrate doses of 2 mg/kg/day and 4 mg/kg/day for 8 days. Treatment with NBV significantly reduced parasite burden compared to vehicle and standard drug (PYR) groups. In the chronic model of experimental toxoplasmosis, C57/BL6 mice infected with the ME49 strain received NBV chlorhydrate 41 days post-infection and were evaluated after 10 days of treatment. NBV chlorhydrate effectively reduced cyst number and area, as well as bradyzoite burden compared to controls. Histological analysis demonstrated that NBV chlorhydrate preserved neuronal count, with the 4 mg/kg/day dose yielding counts similar to non-infected mice. Statistical analysis confirmed significant differences compared to control groups. Furthermore, immunohistochemical analysis revealed a significant reduction in iNOS labeling in the brains of mice treated with NBV chlorhydrate, indicating a decrease in nitric oxide production compared to control groups. These findings suggest NBV's potential as a promising candidate for toxoplasmosis treatment, highlighting its ability to reduce parasite burden and protect neuronal integrity. Further research is warranted to elucidate NBV's mechanisms of action and its clinical application in managing toxoplasmosis.
Asunto(s)
Encéfalo , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Nebivolol , Carga de Parásitos , Toxoplasmosis Animal , Animales , Nebivolol/farmacología , Nebivolol/uso terapéutico , Ratones , Toxoplasmosis Animal/tratamiento farmacológico , Toxoplasmosis Animal/parasitología , Encéfalo/parasitología , Encéfalo/patología , Encéfalo/efectos de los fármacos , Femenino , Neuronas/efectos de los fármacos , Neuronas/parasitología , Etanolaminas/farmacología , Etanolaminas/uso terapéutico , Antiprotozoarios/farmacología , Antiprotozoarios/uso terapéutico , Antiprotozoarios/administración & dosificación , Benzopiranos/farmacología , Benzopiranos/uso terapéutico , Resultado del Tratamiento , Óxido Nítrico/metabolismo , Toxoplasma/efectos de los fármacos , Óxido Nítrico Sintasa de Tipo II/metabolismoRESUMEN
Seizures are neurological disorders triggered by an imbalance in the activity of excitatory and inhibitory neurotransmitters in the brain. When triggered chronically, this imbalance can lead to epilepsy. Critically, many of the affected individuals are refractory to treatment. Given this, anti-inflammatory drugs, in particular glucocorticoids, have been considered as a potential antiepileptogenic therapy. Glucocorticoids are currently used in the treatment of refractory patients, although there have been contradictory results in terms of their use in association with antiepileptic drugs, which reinforces the need for a more thorough investigation of their effects. In this context, the present study evaluated the effects of dexamethasone (DEX, 0.6 mg/kg) on the electroencephalographic (EEG) and histopathological parameters of male Wistar rats submitted to acute seizure induced by pentylenetetrazol (PTZ). The EEG monitoring revealed that DEX reduced the total brainwave power, in comparison with PTZ, in 12 h after the convulsive episode, exerting this effect in up to 36 h (p < 0.05 for all comparisons). An increase in the accommodation of the oscillations of the delta, alpha, and gamma frequencies was also observed from the first 12 h onwards, with the accommodation of the theta frequency occurring after 36 h, and that of the beta frequency 24 h after the seizure. The histopathological analyses showed that the CA3 region and hilum of the hippocampus suffered cell loss after the PTZ-induced seizure (control vs. PTZ, p < 0.05), although DEX was not able to protect these regions against cell death (PTZ vs. DEX + PTZ, p > 0.05). While DEX did not reverse the cell damage caused by PTZ, the data indicate that DEX has beneficial properties in the EEG analysis, which makes it a promising candidate for the attenuation of the epileptiform wave patterns that can precipitate refractory seizures.
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Ondas Encefálicas , Dexametasona , Electroencefalografía , Pentilenotetrazol , Ratas Wistar , Convulsiones , Animales , Dexametasona/farmacología , Dexametasona/efectos adversos , Pentilenotetrazol/toxicidad , Convulsiones/tratamiento farmacológico , Convulsiones/inducido químicamente , Convulsiones/fisiopatología , Masculino , Ratas , Ondas Encefálicas/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/patología , Encéfalo/fisiopatología , Anticonvulsivantes/farmacología , Hipocampo/efectos de los fármacos , Hipocampo/patología , Hipocampo/fisiopatologíaRESUMEN
PURPOSE: Stereotactic brain biopsies are highly efficient for diagnosing intracerebral pathologies, particularly when surgical resection is infeasible. Fluorescence-based agents such as 5-aminolevulinic acid (5-ALA) and fluorescein sodium (NaFl) can enhance diagnostic accuracy and safety, improving the visualization of lesional tissues. This meta-analysis aimed to evaluate their effect on diagnostic yield and complication rates of brain biopsies. METHODS: This study adhered to Cochrane and PRISMA guidelines. We assessed studies for diagnostic yield and complication rates. Data was analyzed using a random-effects model in RStudio. Diagnostic accuracy measures such as sensitivity and predictive values were calculated based on fluorescence visibility in biopsy samples. RESULTS: Thirty-two non-randomized studies were included, comprising 947 patients, with a mean age ranging from 37 to 77 years, and a mean sample number ranging from 1 to 15 specimens. Diagnostic yields were high: 93% for NaFl and 96% for 5-ALA. Major complications occurred in 3% of procedures with both agents, while minor complications were reported in 7% and 5% with NaFl and 5-ALA respectively. The Negative-predictive-value (NPV) of 5-ALA and NaFl were 8-11% and 60-80% respectively. NaFl demonstrates higher sensitivity and specificity at 84% and 100% compared to 5-ALA's 66%. and 85% respectively. CONCLUSION: 5-ALA and NaFl provide high diagnostic yields with acceptable safety profiles in stereotactic biopsies. NaFl showed higher sensitivity and specificity. NaFl outperforms 5ALA in terms of NPV making it more efficient for small lesions near eloquent regions or major blood vessels. The significance of these findings can be further ascertained through randomized trials.
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Ácido Aminolevulínico , Neoplasias Encefálicas , Fluoresceína , Humanos , Encéfalo/patología , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/cirugía , Colorantes Fluorescentes , Biopsia Guiada por Imagen/métodosRESUMEN
BACKGROUND: Education influences brain health and dementia. However, its impact across regions, specifically Latin America (LA) and the United States (US), is unknown. METHODS: A total of 1412 participants comprising controls, patients with Alzheimer's disease (AD), and frontotemporal lobar degeneration (FTLD) from LA and the US were included. We studied the association of education with brain volume and functional connectivity while controlling for imaging quality and variability, age, sex, total intracranial volume (TIV), and recording type. RESULTS: Education influenced brain measures, explaining 24%-98% of the geographical differences. The educational disparities between LA and the US were associated with gray matter volume and connectivity variations, especially in LA and AD patients. Education emerged as a critical factor in classifying aging and dementia across regions. DISCUSSION: The results underscore the impact of education on brain structure and function in LA, highlighting the importance of incorporating educational factors into diagnosing, care, and prevention, and emphasizing the need for global diversity in research. HIGHLIGHTS: Lower education was linked to reduced brain volume and connectivity in healthy controls (HCs), Alzheimer's disease (AD), and frontotemporal lobar degeneration (FTLD). Latin American cohorts have lower educational levels compared to the those in the United States. Educational disparities majorly drive brain health differences between regions. Educational differences were significant in both conditions, but more in AD than FTLD. Education stands as a critical factor in classifying aging and dementia across regions.
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Enfermedad de Alzheimer , Encéfalo , Escolaridad , Imagen por Resonancia Magnética , Humanos , América Latina , Masculino , Femenino , Estados Unidos , Encéfalo/patología , Encéfalo/diagnóstico por imagen , Anciano , Enfermedad de Alzheimer/patología , Persona de Mediana Edad , Degeneración Lobar Frontotemporal/patología , Demencia/patología , Demencia/epidemiologíaRESUMEN
PURPOSE: Amid rising health awareness, natural products which has milder effects than medical drugs are becoming popular. However, only few systems can quantitatively assess their impact on living organisms. Therefore, we developed a deep-learning system to automate the counting of cells in a gerbil model, aiming to assess a natural product's effectiveness against ischemia. METHODS: The image acquired from paraffin blocks containing gerbil brains was analyzed by a deep-learning model (fine-tuned Detectron2). RESULTS: The counting system achieved a 79%-positive predictive value and 85%-sensitivity when visual judgment by an expert was used as ground truth. CONCLUSIONS: Our system evaluated hydrogen water's potential against ischemia and found it potentially useful, which is consistent with expert assessment. Due to natural product's milder effects, large data sets are needed for evaluation, making manual measurement labor-intensive. Hence, our system offers a promising new approach for evaluating natural products.
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Isquemia Encefálica , Modelos Animales de Enfermedad , Gerbillinae , Animales , Isquemia Encefálica/patología , Aprendizaje Profundo , Encéfalo/patología , Encéfalo/irrigación sanguínea , Procesamiento de Imagen Asistido por Computador/métodosRESUMEN
Rasmussen's encephalitis (RE) stands as a rare neurological disorder marked by progressive cerebral hemiatrophy and epilepsy resistant to medical treatment. Despite extensive study, the primary cause of RE remains elusive, while its histopathological features encompass cortical inflammation, neuronal degeneration, and gliosis. The underlying molecular mechanisms driving disease progression remain largely unexplored. In this case study, we present a patient with RE who underwent hemispherotomy and has remained seizure-free for over six months, experiencing gradual motor improvement. Furthermore, we conducted molecular analysis on the excised brain tissue, unveiling a decrease in the expression of cell-cycle-associated genes coupled with elevated levels of BDNF and TNF-α proteins. These findings suggest the potential involvement of cell cycle regulators in the progression of RE.
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Encefalitis , Humanos , Encefalitis/genética , Encefalitis/patología , Encefalitis/metabolismo , Masculino , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Encéfalo/patología , Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Corteza Cerebral/patología , Corteza Cerebral/metabolismo , Femenino , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/genética , Ciclo Celular/genéticaRESUMEN
Zika virus (ZIKV) infection was first reported in 2015 in Brazil as causing microcephaly and other developmental abnormalities in newborns, leading to the identification of Congenital Zika Syndrome (CZS). Viral infections have been considered an environmental risk factor for neurodevelopmental disorders outcome, such as Autism Spectrum Disorder (ASD). Moreover, not only the infection per se, but maternal immune system activation during pregnancy, has been linked to fetal neurodevelopmental disorders. To understand the impact of ZIKV vertical infection on brain development, we derived induced pluripotent stem cells (iPSC) from Brazilian children born with CZS, some of the patients also being diagnosed with ASD. Comparing iPSC-derived neurons from CZS with a control group, we found lower levels of pre- and postsynaptic proteins and reduced functional synapses by puncta co-localization. Furthermore, neurons and astrocytes derived from the CZS group showed decreased glutamate levels. Additionally, the CZS group exhibited elevated levels of cytokine production, one of which being IL-6, already associated with the ASD phenotype. These preliminary findings suggest that ZIKV vertical infection may cause long-lasting disruptions in brain development during fetal stages, even in the absence of the virus after birth. These disruptions could contribute to neurodevelopmental disorders manifestations such as ASD. Our study contributes with novel knowledge of the CZS outcomes and paves the way for clinical validation and the development of potential interventions to mitigate the impact of ZIKV vertical infection on neurodevelopment.
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Encéfalo , Células Madre Pluripotentes Inducidas , Transmisión Vertical de Enfermedad Infecciosa , Sinapsis , Infección por el Virus Zika , Virus Zika , Humanos , Infección por el Virus Zika/virología , Infección por el Virus Zika/patología , Femenino , Virus Zika/patogenicidad , Sinapsis/patología , Sinapsis/metabolismo , Encéfalo/virología , Encéfalo/patología , Embarazo , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/virología , Neuronas/virología , Neuronas/metabolismo , Neuronas/patología , Masculino , Astrocitos/virología , Astrocitos/metabolismo , Enfermedades Neuroinflamatorias/virología , Enfermedades Neuroinflamatorias/patología , Enfermedades Neuroinflamatorias/metabolismo , Complicaciones Infecciosas del Embarazo/virología , Complicaciones Infecciosas del Embarazo/patología , Brasil , Recién Nacido , Trastorno del Espectro Autista/virología , NiñoRESUMEN
Patients recovering from COVID-19 commonly exhibit cognitive and brain alterations, yet the specific neuropathological mechanisms and risk factors underlying these alterations remain elusive. Given the significant global incidence of COVID-19, identifying factors that can distinguish individuals at risk of developing brain alterations is crucial for prioritizing follow-up care. Here, we report findings from a sample of patients consisting of 73 adults with a mild to moderate SARS-CoV-2 infection without signs of respiratory failure and 27 with infections attributed to other agents and no history of COVID-19. The participants underwent cognitive screening, a decision-making task, and MRI evaluations. We assessed for the presence of anosmia and the requirement for hospitalization. Groups did not differ in age or cognitive performance. Patients who presented with anosmia exhibited more impulsive alternative changes after a shift in probabilities (r = - 0.26, p = 0.001), while patients who required hospitalization showed more perseverative choices (r = 0.25, p = 0.003). Anosmia correlated with brain measures, including decreased functional activity during the decision-making task, thinning of cortical thickness in parietal regions, and loss of white matter integrity. Hence, anosmia could be a factor to be considered when identifying at-risk populations for follow-up.
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Anosmia , Encéfalo , COVID-19 , Imagen por Resonancia Magnética , SARS-CoV-2 , Humanos , COVID-19/complicaciones , COVID-19/psicología , COVID-19/fisiopatología , COVID-19/diagnóstico por imagen , COVID-19/patología , Anosmia/etiología , Anosmia/fisiopatología , Masculino , Femenino , Persona de Mediana Edad , Adulto , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Encéfalo/fisiopatología , SARS-CoV-2/aislamiento & purificación , Anciano , Toma de Decisiones , Cognición/fisiologíaRESUMEN
Calcified cysticerci are often associated with hippocampal atrophy (HA). While most studies suggest that repetitive seizures cause HA in these patients, others have demonstrated that HA may also occur in persons without epilepsy. Little is known about mechanisms triggering HA in seizure-free individuals with calcified cysticerci. Here, we aimed to assess whether the size of the calcification is associated with HA. Using a population-based design, we selected apparently seizure-free individuals with a single calcified cysticercus in whom interictal paroxysmal activity and other causes of HA have been discarded. A total of 55 individuals (mean age, 58.3 ± 13 years, 62% women) fulfilled inclusion criteria. Unadjusted and multivariate models were fitted to assess the association between the size of the calcification dichotomized into <3 mm and ≥3 mm (exposure) and the presence of HA (outcome). Sixteen participants (29%) had HA, which was asymmetric in eight (50%) cases. Hippocampal atrophy was noted in 11/20 (55%) participants with large calcifications and in 5/35 (14%) with small calcifications (P = 0.001). A multivariate logistic regression model showed a significant association between the presence of large calcifications and HA, after adjustment for relevant confounders (odds ratio: 7.78; 95% CI: 1.72-35.1). Participants with calcifications ≥3 mm in diameter were 7.8 times more likely to have HA than those with smaller ones. Study results open avenues of research for the use of agents to prevent HA progression.
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Atrofia , Calcinosis , Hipocampo , Humanos , Femenino , Hipocampo/patología , Masculino , Persona de Mediana Edad , Atrofia/patología , Calcinosis/patología , Anciano , Neurocisticercosis/complicaciones , Neurocisticercosis/patología , Neurocisticercosis/diagnóstico por imagen , Adulto , Convulsiones/patología , Encéfalo/patología , Encéfalo/diagnóstico por imagenRESUMEN
INTRODUCTION: This study investigates primary lateral sclerosis (PLS) as a rare manifestation of the presenilin 1 (PSEN1) NM_000021 c.851C > T p.Pro284Leu variant in three siblings of a Colombian family, outlining its clinical and neuropathological features and their relationship to Alzheimer's disease (AD). METHODS: Data were gathered using clinical evaluations, next-generation genetic sequencing, magnetic resonance imaging, biomarker analysis, and neuropathological examination. RESULTS: Carriers of the PSEN1 Pro284Leu variant exhibited classic PLS symptoms, including unilateral onset and bulbar syndromes, along with cognitive decline. Neuropathology showed corticospinal tract degeneration without amyloid beta deposition in spinal white matter. DISCUSSION: Our findings suggest an overlap between PLS and AD pathology in PSEN1 variant carriers. Results support considering PLS when diagnosing AD-related motor syndromes and including PSEN1 evaluation when performing genetic testing for PLS. The study highlights the need for further research to clarify the PLS-AD relationship, informing future treatments and clinical trials. HIGHLIGHTS: Pathogenic variants in presenilin 1 (PSEN1) can manifest as hereditary primary lateral sclerosis PSEN1 Pro284Leu carriers present motor, cognitive, and behavioral alterations Cases had corticospinal tract microgliosis and severe Aß pathology in motor cortex There was no evidence of amyloid deposition in the spinal cord white matter All the neuropathology images are available for online visualization Myelin pallor in the spinal cord is confined to the lateral corticospinal tracts.
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Enfermedad de Alzheimer , Presenilina-1 , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Encéfalo/patología , Encéfalo/diagnóstico por imagen , Colombia , Imagen por Resonancia Magnética , Presenilina-1/genéticaRESUMEN
Alzheimer's disease is characterized by progressive cognitive decline, and behavioural and psychological symptoms of dementia are common. The APOE ε4 allele, a genetic risk factor, significantly increases susceptibility to the disease. Despite efforts to effectively treat the disease, only seven drugs are approved for its treatment, and only two of these prevent its progression. This highlights the need to identify new pharmacological options. This review focuses on mimetic peptides, small molecule correctors and HAE-4 antibodies that target ApoE. These drugs reduce ß-amyloid-induced neurodegeneration in preclinical models. In addition, loop diuretics such as bumetanide and furosemide show the potential to reduce the prevalence of Alzheimer's disease in humans, and antidepressants such as imipramine improve cognitive function in individuals diagnosed with Alzheimer's disease. Consistent with this, both classes of drugs have been shown to exert neuroprotective effects by inhibiting ApoE4-catalysed Aß aggregation in preclinical models. Moreover, peroxisome proliferator-activated receptor ligands, particularly pioglitazone and rosiglitazone, reduce ApoE4-induced neurodegeneration in animal models. However, they do not prevent the cognitive decline in APOE ε4 allele carriers. Finally, ApoE4 impairs the integrity of the blood-brain barrier and haemostasis. On this basis, ApoE4 modulation is a promising avenue for the treatment of late-onset Alzheimer's disease.
Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Apolipoproteína E4 , Encéfalo , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Humanos , Apolipoproteína E4/metabolismo , Apolipoproteína E4/genética , Animales , Péptidos beta-Amiloides/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/patología , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Agregación Patológica de Proteínas/tratamiento farmacológico , Agregación Patológica de Proteínas/metabolismo , Modelos Animales de EnfermedadRESUMEN
Importance: Race differences in dementia prevalence and incidence have previously been reported, with higher dementia burden in Black decedents. However, previous neuropathological studies were conducted mostly in convenience samples with White participants; conducting clinicopathological studies across populations is crucial for understanding the underlying dementia causes in individuals from different racial backgrounds. Objective: To compare the frequencies of neuropathological lesions and cognitive abilities between Black and White Brazilian adults in an autopsy study. Design, Setting, and Participants: This cross-sectional study used samples from the Biobank for Aging Studies, a population-based autopsy study conducted in Sao Paulo, Brazil. Participants were older adults whose family members consented to the brain donations; Asian participants and those with missing data were excluded. Samples were collected from 2004 to 2023. Neuropathologists were masked to cognitive outcomes. Exposure: Race as reported by the deceased's family member. Main Outcomes and Measures: The frequencies of neurodegenerative and cerebrovascular lesions were evaluated in 13 selected cerebral areas. Cognitive and functional abilities were examined with the Clinical Dementia Rating Scale. Results: The mean (SD) age of the 1815 participants was 74.0 (12.5) years, 903 (50%) were women, 617 (34%) were Black, and 637 (35%) had cognitive impairment. Small vessel disease (SVD) and siderocalcinosis were more frequent in Black compared with White participants (SVD: odds ratio [OR], 1.74; 95% CI, 1.29-2.35; P < .001; siderocalcinosis: OR, 1.70; 95% CI, 1.23-2.34; P = .001), while neuritic plaques were more frequent in White compared with Black participants (OR, 0.61; 95% CI, 0.44-0.83; P = .002). Likewise, Alzheimer disease neuropathological diagnosis was more frequent in White participants than Black participants (198 [39%] vs 77 [33%]), while vascular dementia was more common among Black participants than White participants (76 [32%] vs 121 [24%]). Race was not associated with cognitive abilities, nor did it modify the association between neuropathology and cognition. Conclusions and Relevance: In this cross-sectional study of Brazilian older adults, Alzheimer disease pathology was more frequent in White participants while vascular pathology was more frequent in Black participants. Further neuropathological studies in diverse samples are needed to understand race disparities in dementia burden.