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1.
Neuroimage ; 276: 120185, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37244320

RESUMO

OBJECTIVE: Blood-oxygen-level-dependent functional MRI allows to investigte neural activities and connectivity. While the non-human primate plays an essential role in neuroscience research, multimodal methods combining functional MRI with other neuroimaging and neuromodulation enable us to understand the brain network at multiple scales. APPROACH: In this study, a tight-fitting helmet-shape receive array with a single transmit loop for anesthetized macaque brain MRI at 7T was fabricated with four openings constructed in the coil housing to accommodate multimodal devices, and the coil performance was quantitatively evaluated and compared to a commercial knee coil. In addition, experiments over three macaques with infrared neural stimulation (INS), focused ultrasound stimulation (FUS), and transcranial direct current stimulation (tDCS) were conducted. MAIN RESULTS: The RF coil showed higher transmit efficiency, comparable homogeneity, improved SNR and enlarged signal coverage over the macaque brain. Infrared neural stimulation was applied to the amygdala in deep brain region, and activations in stimulation sites and connected sites were detected, with the connectivity consistent with anatomical information. Focused ultrasound stimulation was applied to the left visual cortex, and activations were acquired along the ultrasound traveling path, with all time course curves consistent with pre-designed paradigms. The existence of transcranial direct current stimulation electrodes brought no interference to the RF system, as evidenced through high-resolution MPRAGE structure images. SIGNIFICANCE: This pilot study reveals the feasibility for brain investigation at multiple spatiotemporal scales, which may advance our understanding in dynamic brain networks.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Animais , Haplorrinos , Projetos Piloto , Imageamento por Ressonância Magnética , Neuroimagem , Encéfalo/diagnóstico por imagem , Macaca , Desenho de Equipamento , Imagens de Fantasmas , Ondas de Rádio , Razão Sinal-Ruído
2.
Macromol Rapid Commun ; 44(1): e2200273, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35583906

RESUMO

Herein, the direct morphological evidence of the extension-induced phase-separated structures in the electrospinning jet observed by high-speed video imaging and by light scattering technique is reported. Model solutions of poly(vinyl alcohol) (PVA)/water are electrospun. Two types of internal structures, that is, long strings and short ellipsoids, are found. A light scattering model is derived for the Vv scattering configuration to account for the scattered intensities contributed from the liquid jet itself and those from the internal structures. For the severely stretching jet of PVA/water, the Vv intensity profile is dominant by the internal structures to mask the scattering contribution from the jet itself. Moreover, the Hv intensity profile reflects the anisotropy of the oriented chains parallel to the jet axis. For the 7 wt% solution, the derived extension rate in the vicinity of the Taylor cone apex is about 3420 s-1 , which is higher than the Rouse relaxation rate measured by rheometer. It is concluded that extension-induced phase separation of the single-phase PVA solution is likely to occur in Taylor-cone apex to trigger the self-assembly process for producing strings (and/or bulges) in the flowing jet, which eventually transform to become the nanofibers, after solvent removal, to be collected on the grounded collector.


Assuntos
Nanofibras , Álcool de Polivinil , Álcool de Polivinil/química , Nanofibras/química , Água/química , Anisotropia
3.
BMC Public Health ; 22(1): 1486, 2022 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-35927651

RESUMO

BACKGROUND: Truck drivers have difficulties participating in health education programs delivered at a fixed time and place due to the mobility of their workplace. Interventions conducted via social media can overcome these limitations of time and place. This study aimed to investigate the effect of a nutrition education intervention program delivered via a social media platform on the healthy eating behaviors of truck drivers. METHODS: This study adopted a quasi-experimental design. A 12-week intervention program was conducted for a social-media group (n = 125) and a conventional-teaching group (n = 117) from February to May 2020. The social-media group participated in a social-media-based health intervention on the LINE application. The intervention involved the provision of online messages, online instant responses, a picture-based food log, an audio e-book, and a loyalty e-card. The conventional-teaching group participated in a healthy diet course and a hygiene education manual. The generalized estimation equation (GEE) was applied to evaluate the intervention effects on the outcome measures derived from the Health Belief Model. RESULTS: The results of the GEE showed the social-media-based intervention strategies significantly decreased perceived barriers of consuming a healthy diet (p = < 0.001), increased willingness to follow cues of action (p = 0.036), improved the self-efficacy of healthy eating behaviors (p = 0.001), and increased the score of healthy eating behaviors (p < 0.001) compared with the conventional teaching strategies. For the social-media and conventional-teaching groups, no significant changes occurred in self-perceived health status, self-perceived susceptibility, or self-perceived severity after the intervention. More than 90% of the participants in the social-media group believed the social-media-based intervention strategies could help implement and maintain healthy eating behaviors. CONCLUSIONS: The results indicate social-media-based intervention strategies can facilitate approaching a population without a fixed workplace, such as truck drivers. Health promoters and planners focusing on occupational health can consider developing social-media-based intervention strategies for improving truck drivers' health status.


Assuntos
Veículos Automotores , Mídias Sociais , Dieta Saudável , Comportamento Alimentar , Humanos , Projetos de Pesquisa
4.
J Formos Med Assoc ; 121(3): 718-722, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34373176

RESUMO

In 2019, a large outbreak of a novel coronavirus disease (COVID-19) occurred in China. The purpose of this study is to quantitatively analyze the evolution of chest computed tomography (CT) imaging features in COVID-19. Nine patients with positive real-time reverse-transcriptase polymerase chain reaction results were included in this study. Totally 19 CT scans were analyzed. Lesion density, lesion volume, and lesion load were higher in the severe group than in the mild group. A significantly positive correlation was noted between major laboratory prognosticators with lesion volume and load. Lesion load at the first week of disease was significantly higher in severe group (p = 0.03). Our study revealed that several CT features were significantly different between severely and mildly infected forms of COVID-19 pneumonia. The CT lesion load value at the first week of infection may be applied as an outcome predictor of the disease.


Assuntos
COVID-19 , COVID-19/diagnóstico por imagem , Humanos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Estudos Retrospectivos , SARS-CoV-2 , Tomografia Computadorizada por Raios X/métodos
5.
Int J Sports Med ; 42(7): 610-623, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33321523

RESUMO

Exercise can alter the composition of gut microbiota. However, studies examining the effects of exercise on gut microbiota in the elderly are lacking. This study aims to investigate whether an 8-week exercise training affect gut microbiota in physically inactive elderly women. Fourteen women were randomly assigned to either exercise group or control group. Repeated-measures analysis of variance was used to reveal changes in gut microbiota. Alpha diversity did not change significantly. A tendency to form 2 clusters was observed for operational taxonomic units (OTU) after intervention. At phylum, class, and order levels, a significant difference was observed between two groups for Fusobacteria (F=5.257, P=0.045), Betaproteobacteria (F=5.149, P=0.047), and Bifidobacteriales (F=7.624, P=0.020). A significant interaction was observed between two groups for Actinobacteria (F=8.434, P=0.016). At family and genus levels, a significant main effect of groups was observed in Bifidobacteriaceae (F=7.624, P=0.020), Bifidobacterium (F=7.404, P=0.022), and Gemmiger (F=5.881, P=0.036). These findings indicate that an 8-week exercise training may induce partial changes in relative abundance and OTU clustering of gut microbiota in physically inactive elderly women. Also, exercise may increase the abundance of bacteria associated with anti-inflammation such as Verrucomicrobia, reduce the abundance of bacteria associated with pro-inflammation such as Proteobacteria.


Assuntos
Exercício Físico/fisiologia , Microbioma Gastrointestinal/fisiologia , Idoso , Fezes/microbiologia , Feminino , Humanos , Pessoa de Meia-Idade , Comportamento Sedentário
6.
Sensors (Basel) ; 21(19)2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34640699

RESUMO

Intracortical brain-computer interfaces (iBCIs) translate neural activity into control commands, thereby allowing paralyzed persons to control devices via their brain signals. Recurrent neural networks (RNNs) are widely used as neural decoders because they can learn neural response dynamics from continuous neural activity. Nevertheless, excessively long or short input neural activity for an RNN may decrease its decoding performance. Based on the temporal attention module exploiting relations in features over time, we propose a temporal attention-aware timestep selection (TTS) method that improves the interpretability of the salience of each timestep in an input neural activity. Furthermore, TTS determines the appropriate input neural activity length for accurate neural decoding. Experimental results show that the proposed TTS efficiently selects 28 essential timesteps for RNN-based neural decoders, outperforming state-of-the-art neural decoders on two nonhuman primate datasets (R2=0.76±0.05 for monkey Indy and CC=0.91±0.01 for monkey N). In addition, it reduces the computation time for offline training (reducing 5-12%) and online prediction (reducing 16-18%). When visualizing the attention mechanism in TTS, the preparatory neural activity is consecutively highlighted during arm movement, and the most recent neural activity is highlighted during the resting state in nonhuman primates. Selecting only a few essential timesteps for an RNN-based neural decoder provides sufficient decoding performance and requires only a short computation time.


Assuntos
Interfaces Cérebro-Computador , Animais , Conscientização , Aprendizagem , Movimento , Redes Neurais de Computação
7.
Rev Cardiovasc Med ; 19(3): 111-112, 2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31054560

RESUMO

A 43-year-old man presented with exertional dyspnea and chest tightness for two months. He received coronary computed tomography angiography and the result revealed a single coronary artery, a rare congenital coronary artery anomaly.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Anomalias dos Vasos Coronários/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Imageamento Tridimensional/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Adulto , Humanos , Masculino , Valor Preditivo dos Testes
8.
Neurobiol Dis ; 75: 53-63, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25573087

RESUMO

To investigate the potential therapeutic effects of peripheral sensory stimulation during the hyperacute phase of stroke, the present study utilized electrophysiology and photoacoustic imaging techniques to evaluate neural and vascular responses of the rat cortex following ischemic insult. We employed a rat model of photothrombotic ischemia (PTI), which targeted the forelimb region of the primary somatosensory cortex (S1FL), due to its high reproducibility in creating localized ischemic injury. We also established a hybrid, dual-modality system, including six-channel electrocorticography (ECoG) and functional photoacoustic microscopy (fPAM), termed ECoG-fPAM, to image brain functional responses to peripheral sensory stimulation during the hyperacute phase of PTI. Our results showed that the evoked cerebral blood volume (CBV) and hemoglobin oxygen saturation (SO2) recovered to 84±7.4% and 79±6.2% of the baseline, respectively, when stimulation was delivered within 2.5 h following PTI induction. Moreover, neural activity significantly recovered, with 77±8.6%, 76±5.3% and 89±8.2% recovery for the resting-state inter-hemispheric coherence, alpha-to-delta ratio (ADR) and somatosensory evoked potential (SSEP), respectively. Additionally, we integrated the CBV or SO2 with ADR values as a recovery indicator (RI) to assess functional recovery after PTI. The RI indicated that 80±4.2% of neurovascular function was preserved when stimulation was delivered within 2.5h. Additionally, stimulation treatment within this optimal time window resulted in a minimal infarct volume in the ischemic hemisphere (4.6±2.1%). In contrast, the infarct volume comprised 13.7±1.7% of the ischemic hemisphere when no stimulation treatment was applied.


Assuntos
Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/terapia , Terapia por Estimulação Elétrica/métodos , Córtex Somatossensorial/fisiopatologia , Animais , Volume Sanguíneo/fisiologia , Determinação do Volume Sanguíneo , Isquemia Encefálica/patologia , Circulação Cerebrovascular/fisiologia , Modelos Animais de Doenças , Eletroencefalografia/instrumentação , Eletroencefalografia/métodos , Potenciais Somatossensoriais Evocados/fisiologia , Membro Anterior/fisiopatologia , Masculino , Microscopia Acústica/instrumentação , Microscopia Acústica/métodos , Ratos Wistar , Recuperação de Função Fisiológica/fisiologia , Córtex Somatossensorial/patologia , Fatores de Tempo
9.
Neurobiol Dis ; 82: 455-465, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26149348

RESUMO

This study developed a novel system combining a 16-channel micro-electrocorticography (µECoG) electrode array and functional photoacoustic microscopy (fPAM) to examine changes in neurovascular functions following transient ischemic attack (TIA) in rats. To mimic the pathophysiology of TIA, a modified photothrombotic ischemic model was developed by using 3 min illumination of 5 mW continuous-wave (CW) green laser light focusing on a distal branch of the middle cerebral artery (MCA). Cerebral blood volume (CBV), hemoglobin oxygen saturation (SO2), somatosensory evoked potentials (SSEPs) and alpha-to-delta ratio (ADR) were measured pre- and post-ischemia over a focal cortical region (i.e., 1.5×1.5 mm(2)). Unexpectedly, the SO2, peak-to-peak amplitude (PPA) of SSEPs and ADR recovered and achieved levels greater than the baseline values at the 4th hour post-ischemia induction without any intervention, whereas the CBV value only partially recovered. In other words, transient ischemia led to increased neural activity when the relative CBV was reduced, which may further compromise neural integrity or lead to subsequent vascular disease. This novel µECoG-fPAM system complements currently available imaging techniques and represents a promising technology for studying neurovascular coupling in animal models.


Assuntos
Córtex Cerebral/fisiopatologia , Circulação Cerebrovascular/fisiologia , Eletrocorticografia/métodos , Ataque Isquêmico Transitório/fisiopatologia , Microscopia Acústica/métodos , Técnicas Fotoacústicas/métodos , Ritmo alfa , Animais , Volume Sanguíneo , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/patologia , Ritmo Delta , Modelos Animais de Doenças , Estimulação Elétrica , Eletrocorticografia/instrumentação , Eletrodos Implantados , Desenho de Equipamento , Potenciais Somatossensoriais Evocados , Ataque Isquêmico Transitório/patologia , Lasers , Masculino , Microscopia Acústica/instrumentação , Artéria Cerebral Média , Técnicas Fotoacústicas/instrumentação , Ratos Sprague-Dawley , Fatores de Tempo
10.
Magn Reson Med ; 73(3): 1246-51, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24798216

RESUMO

PURPOSE: To develop a series of robust and readily adoptable protocols for the application of deep brain stimulation (DBS)-functional MRI (fMRI) in rodents. METHODS: DBS-fMRI procedures were conducted in rat and mouse under varying anesthetic conditions (isoflurane in rat and mouse, α-chloralose in rat). A homemade two-channel tungsten microwire electrode was used to minimize magnetic susceptibility artifacts, and was targeted to the ventral posteromedial (VPM) thalamus for DBS-fMRI scanning procedures. RESULTS: Compared with a commercially available MR-compatible electrode, the tungsten microwire generated greatly reduced magnetic-susceptibility artifacts. In the rat, VPM-DBS using the microwire electrode resulted in robust positive blood-oxygen-level-dependent signal changes in somatosensory cortex that were relatively independent of anesthetic type. In the mouse, VPM-DBS similarly generated large, positive neurovascular responses in somatosensory cortex that were detected using cerebral blood volume measurements. CONCLUSION: Collectively, this work describes reasonable and easily adoptable procedures for conducting DBS-fMRI studies in rodent models. The protocols developed herein may be extended to study DBS effects under numerous experimental conditions and at varying stimulation targets.


Assuntos
Encéfalo/fisiologia , Estimulação Encefálica Profunda/instrumentação , Potenciais Evocados/fisiologia , Imageamento por Ressonância Magnética/instrumentação , Microeletrodos , Tungstênio , Animais , Materiais Biocompatíveis/síntese química , Encéfalo/anatomia & histologia , Desenho de Equipamento , Análise de Falha de Equipamento , Masculino , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
11.
J Org Chem ; 80(16): 8458-63, 2015 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-26240938

RESUMO

We have established a concise synthetic route relying on a key base-promoted epimerization step to synthesize two series of activity-based probes carrying a BODIPY fluorophore for α-l-fucosidase. The resulting probes were evaluated for labeling performance. The one utilizing an o-fluoromethylphenol derivative as the latent trapping unit was successfully applied for the first time to visualize and locate lysosomal α-l-fucosidase activity in human cells.


Assuntos
Compostos de Boro/química , Membrana Celular/química , Fenóis/química , alfa-L-Fucosidase/química , Membrana Celular/enzimologia , Fluorescência , Humanos , Cinética
12.
Sensors (Basel) ; 15(6): 12700-19, 2015 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-26029954

RESUMO

Deep brain stimulation (DBS) is one of the most effective therapies for movement and other disorders. The DBS neurosurgical procedure involves the implantation of a DBS device and a battery-operated neurotransmitter, which delivers electrical impulses to treatment targets through implanted electrodes. The DBS modulates the neuronal activities in the brain nucleus for improving physiological responses as long as an electric discharge above the stimulation threshold can be achieved. In an effort to improve the performance of an implanted DBS device, the device size, implementation cost, and power efficiency are among the most important DBS device design aspects. This study aims to present preliminary research results of an efficient stimulator, with emphasis on conversion efficiency. The prototype stimulator features high-voltage compliance, implemented with only a standard semiconductor process, without the use of extra masks in the foundry through our proposed circuit structure. The results of animal experiments, including evaluation of evoked responses induced by thalamic electrical stimuli with our fabricated chip, were shown to demonstrate the proof of concept of our design.


Assuntos
Estimulação Encefálica Profunda/instrumentação , Eletrodos Implantados , Próteses Neurais , Semicondutores , Animais , Desenho de Equipamento , Membro Anterior/fisiologia , Masculino , Ratos Wistar , Córtex Somatossensorial/fisiologia , Córtex Somatossensorial/cirurgia
13.
Neuroimage ; 84: 11-8, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23988274

RESUMO

Deep brain stimulation (DBS) represents a widely used therapeutic tool for the symptomatic treatment of movement disorders, most commonly Parkinson's disease (PD). High frequency stimulation at both the subthalamic nucleus (STN) and internal globus pallidus (GPi) has been used with great success for the symptomatic treatment of PD, although the therapeutic mechanisms of action remain elusive. To better understand how DBS at these target sites modulates neural circuitry, the present study used functional blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to map global brain responses to DBS at the STN and GPi of the rat. Robust activation centered in the ipsilateral motor cortex was observed during high frequency stimulation at either target site, with peak responses observed at a stimulation frequency of 100Hz. Of note, frequency tuning curves were generated, demonstrating that cortical activation was maximal at clinically-relevant stimulation frequencies. Divergent responses to stimulation were noted in the contralateral hemisphere, with strong cortical and striatal negative BOLD signal during stimulation of the GPi, but not STN. The frequency-dependence of the observed motor cortex activation at both targets suggests a relationship with the therapeutic effects of STN and GPi DBS, with both DBS targets being functionally connected with motor cortex at therapeutic stimulation frequencies.


Assuntos
Ondas Encefálicas/fisiologia , Conectoma/métodos , Estimulação Encefálica Profunda/métodos , Globo Pálido/fisiologia , Córtex Motor/fisiologia , Rede Nervosa/fisiologia , Núcleo Subtalâmico/fisiologia , Animais , Imageamento por Ressonância Magnética/métodos , Masculino , Ratos , Ratos Sprague-Dawley
14.
Neurobiol Dis ; 71: 131-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25066776

RESUMO

Cortical spreading depolarization (CSD) is known to exacerbate ischemic damage, as the number of CSDs correlates with the final infarct volumes and suppressing CSDs improves functional outcomes. To investigate the role of CSD in ischemic damage, we developed a novel rat model of photothrombotic ischemia using a miniature implantable optic fiber that allows lesion induction inside the magnetic resonance imaging (MRI) scanner. We were able to precisely control the location and the size of the ischemic lesion, and continuously monitor dynamic perfusion and diffusion MRI signal changes at high temporal resolution before, during and after the onset of focal ischemia. Our model showed that apparent diffusion coefficient (ADC) and cerebral blood flow (CBF) in the ischemic core dropped immediately after lesion onset by 20±6 and 41±23%, respectively, and continually declined over the next 5h. Meanwhile, CSDs were observed in all animals (n=36) and displayed either a transient decrease of ADC by 17±3% or an increase of CBF by 104±15%. All CSDs were initiated from the rim of the ischemic core, propagated outward, and confined to the ipsilesional cortex. Additionally, we demonstrated that by controlling the size of perfusion-diffusion mismatch (which approximates the penumbra) in our model, the number of CSDs correlated with the mismatch area rather than the final infarct volume. This study introduces a novel platform to study CSDs in real-time with high reproducibility using MRI.


Assuntos
Isquemia Encefálica/diagnóstico , Córtex Cerebral/fisiopatologia , Circulação Cerebrovascular/fisiologia , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Imagem de Difusão por Ressonância Magnética , Análise de Variância , Animais , Isquemia Encefálica/etiologia , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/complicações , Lasers/efeitos adversos , Angiografia por Ressonância Magnética , Masculino , Ratos , Ratos Sprague-Dawley , Rosa Bengala , Fatores de Tempo
15.
J Mol Model ; 30(8): 239, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954107

RESUMO

CONTEXT: This study primarily investigates the changes in carbon adsorption capacity and hydrogen adsorption capacity on the anode catalyst surface when using methane fuel and mixed gas fuel as the anode fuel for SOFC systems. To reduce the carbon adsorption capacity of the commonly used anode catalyst-nickel-based catalysts-towards hydrocarbon fuels, copper and gold are doped into the nickel-based catalysts to compare the effects on carbon and hydrogen adsorption capacities. Moreover, aside from calculating the carbon and hydrogen adsorption capacities, this project also evaluates the impact of mixed gas effects and doping effects on SOFC performance through the analysis of hydrogen diffusion coefficients and performance polarization curves. The findings reveal a noteworthy enhancement in the diffusion coefficient of syngas within the Au-doped Ni catalyst, showing an improvement of up to 45.46% at 973 K. Furthermore, the electrical power generated by syngas in the Au-doped Ni catalyst at 973 K demonstrates an increase of up to 12.06%. METHODS: This study primarily employs DFT to calculate the carbon and hydrogen adsorption energies on methane, utilizing CASTEP for the calculations. During these calculations, the adsorption energy is determined through a three-layer surface approach, in conjunction with the Kohn-Sham equations, combining the Generalized Gradient Approximation and ultrasoft pseudopotentials for TS-search calculations. On the other hand, this project will analyze the diffusion coefficient of hydrogen on the anode catalyst using MD methods combined with the ReaxFF potential field, with GULP being utilized to complete all dynamics calculation theories. Finally, the project will analyze the performance of SOFC cells, incorporating relevant numerical equations with Matlab for numerical analysis.

16.
Neural Regen Res ; 19(9): 1973-1980, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38227524

RESUMO

Parkinson's disease is a common neurodegenerative disorder that is associated with abnormal aggregation and accumulation of neurotoxic proteins, including α-synuclein, amyloid-ß, and tau, in addition to the impaired elimination of these neurotoxic protein. Atypical parkinsonism, which has the same clinical presentation and neuropathology as Parkinson's disease, expands the disease landscape within the continuum of Parkinson's disease and related disorders. The glymphatic system is a waste clearance system in the brain, which is responsible for eliminating the neurotoxic proteins from the interstitial fluid. Impairment of the glymphatic system has been proposed as a significant contributor to the development and progression of neurodegenerative disease, as it exacerbates the aggregation of neurotoxic proteins and deteriorates neuronal damage. Therefore, impairment of the glymphatic system could be considered as the final common pathway to neurodegeneration. Previous evidence has provided initial insights into the potential effect of the impaired glymphatic system on Parkinson's disease and related disorders; however, many unanswered questions remain. This review aims to provide a comprehensive summary of the growing literature on the glymphatic system in Parkinson's disease and related disorders. The focus of this review is on identifying the manifestations and mechanisms of interplay between the glymphatic system and neurotoxic proteins, including loss of polarization of aquaporin-4 in astrocytic endfeet, sleep and circadian rhythms, neuroinflammation, astrogliosis, and gliosis. This review further delves into the underlying pathophysiology of the glymphatic system in Parkinson's disease and related disorders, and the potential implications of targeting the glymphatic system as a novel and promising therapeutic strategy.

17.
ACS Chem Neurosci ; 15(7): 1548-1559, 2024 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-38527459

RESUMO

Ischemic strokes, prevalence and impactful, underscore the necessity of advanced research models closely resembling human physiology. Our study utilizes nonhuman primates (NHPs) to provide a detailed exploration of ischemic stroke, integrating neuroimaging data, behavioral outcomes, and serum proteomics to elucidate the complex interplay of factors involved in stroke pathophysiology. We observed a consistent pattern in infarct volume, peaking at 1-month postmiddle cerebral artery occlusion (MCAO) and then stabilized. This pattern was strongly correlated to notable changes in motor function and working memory performance. Using diffusion tensor imaging (DTI), we detected significant alterations in fractional anisotropy (FA) and mean diffusivity (MD) values, signaling microstructural changes in the brain. These alterations closely correlated with the neurological and cognitive deficits that we observed, highlighting the sensitivity of DTI metrics in stroke assessment. Behaviorally, the monkeys exhibited a reliance on their unaffected limb for compensatory movements, a common response to stroke impairment. This adaptation, along with consistent DTI findings, suggests a significant impact of stroke on motor function and spatial perception. Proteomic analysis through MS/MS functional enrichment identified two distinct groups of proteins with significant changes post-MCAO. Notably, MMP9, THBS1, MB, PFN1, and YWHAZ were identified as potential biomarkers and therapeutic targets for ischemic stroke. Our results underscore the complex nature of stroke and advocate for an integrated approach, combining neuroimaging, behavioral studies, and proteomics, for advancing our understanding and treatment of this condition.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Animais , Humanos , AVC Isquêmico/diagnóstico por imagem , Imagem de Tensor de Difusão/métodos , Proteômica , Espectrometria de Massas em Tandem , Acidente Vascular Cerebral/diagnóstico por imagem , Neuroimagem , Primatas , Profilinas
18.
Neuroimage ; 73: 113-20, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23384528

RESUMO

High-resolution functional-magnetic-resonance-imaging (fMRI) has been used to study brain functions at increasingly finer scale, but whether fMRI can accurately reflect layer-specific neuronal activities is less well understood. The present study investigated layer-specific cerebral-blood-volume (CBV) fMRI and electrophysiological responses in the rat cortex. CBV fMRI at 40×40 µm in-plane resolution was performed on an 11.7-T scanner. Electrophysiology used a 32-channel electrode array that spanned the entire cortical depth. Graded electrical stimulation was used to study activations in different cortical layers, exploiting the notion that most of the sensory-specific neurons are in layers II-V and most of the nociceptive-specific neurons are in layers V-VI. CBV response was strongest in layer IV of all stimulus amplitudes. Current source density analysis showed strong sink currents at cortical layers IV and VI. Multi-unit activities mainly appeared at layers IV-VI and peaked at layer V. Although our measures showed scaled activation profiles during modulation of stimulus amplitude and failed to detect specific recruitment at layers V and VI during noxious electrical stimuli, there appears to be discordance between CBV fMRI and electrophysiological peak responses, suggesting neurovascular uncoupling at laminar resolution. The technique implemented in the present study offers a means to investigate intracortical neurovascular function in the normal and diseased animal models at laminar resolution.


Assuntos
Eletrofisiologia/métodos , Imageamento por Ressonância Magnética/métodos , Córtex Somatossensorial/fisiologia , Animais , Interpretação Estatística de Dados , Estimulação Elétrica , Campos Eletromagnéticos , Membro Anterior/fisiologia , Masculino , Ratos , Ratos Sprague-Dawley , Respiração Artificial , Técnicas Estereotáxicas
19.
Int J Cancer ; 132(6): 1341-50, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-22907255

RESUMO

Activated T regulatory (T(reg)) cells are potent suppressors that mediate immune tolerance. We investigated the relationship between activated T(reg) cells and the progression of human colon cancer. We designed a cross-sectional study of CD4(+) Foxp3(+) T cells from peripheral blood, primary tumor and nontumor colon tissue of 42 patients with colon cancer and correlated the percentages of different subgroups of T(reg) cells with colon cancer stage. The phenotypes, cytokine-release patterns and suppression ability of these T(reg) cells were analyzed. We found that T(reg) cells increased significantly in both peripheral blood and cancer tissue. In addition, the T(reg) cells expressed significantly lower levels of CCR7, CD62L and CD45RA in comparison to normal volunteers. Further dividing T(reg) cells into subgroups based on Foxp3 and CD45RA expression revealed that both activated T(reg) cells (Foxp3(hi) CD45RA(-)) and nonsuppressive T(reg) cells (Foxp3(lo) CD45RA(-)), but not resting T(reg) cells (Foxp3(low) CD45RA(+)), increased in the peripheral blood and cancer tissue of patients with colon cancer. Only the activated T(reg) cells expressed significantly higher levels of tumor necrosis factor receptor 2 and cytotoxic T-cell antigen-4. Activated T(reg) cells, however, secreted significantly lower levels of effector cytokines (interleukin-2, tumor necrosis factor-α and interferon-γ) than did resting T(reg) cells and nonsuppressive cells upon ex vivo stimulation. Activated, but not resting, T(reg) cells in cancer tissue correlated with tumor metastases. In summary, we confirmed that activated T(reg) cells are a distinct subgroup with effector memory phenotype and fully functional regulatory activity against human colorectal cancer immunity.


Assuntos
Neoplasias Colorretais/imunologia , Ativação Linfocitária , Linfócitos T Reguladores/imunologia , Microambiente Tumoral , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígeno CTLA-4/análise , Progressão da Doença , Feminino , Humanos , Memória Imunológica , Antígenos Comuns de Leucócito/análise , Linfócitos do Interstício Tumoral/imunologia , Masculino , Pessoa de Meia-Idade , Receptores Tipo II do Fator de Necrose Tumoral/análise
20.
Biomed Eng Online ; 12: 38, 2013 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-23631798

RESUMO

Optical imaging techniques reflect different biochemical processes in the brain, which is closely related with neural activity. Scientists and clinicians employ a variety of optical imaging technologies to visualize and study the relationship between neurons, glial cells and blood vessels. In this paper, we present an overview of the current optical approaches used for the in vivo imaging of neurovascular coupling events in small animal models. These techniques include 2-photon microscopy, laser speckle contrast imaging (LSCI), voltage-sensitive dye imaging (VSDi), functional photoacoustic microscopy (fPAM), functional near-infrared spectroscopy imaging (fNIRS) and multimodal imaging techniques. The basic principles of each technique are described in detail, followed by examples of current applications from cutting-edge studies of cerebral neurovascular coupling functions and metabolic. Moreover, we provide a glimpse of the possible ways in which these techniques might be translated to human studies for clinical investigations of pathophysiology and disease. In vivo optical imaging techniques continue to expand and evolve, allowing us to discover fundamental basis of neurovascular coupling roles in cerebral physiology and pathophysiology.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/irrigação sanguínea , Encéfalo/fisiologia , Imagem Óptica/métodos , Animais , Humanos , Imagem Multimodal , Pesquisa Translacional Biomédica
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