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1.
Radiol Clin North Am ; 57(6): 1109-1116, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31582038

RESUMO

Occlusion of a cervical or cerebral artery may cause acute ischemic stroke (AIS). Recent advances in AIS treatment by endovascular thrombectomy have led to more widespread use of advanced computed tomography (CT) imaging, including perfusion CT (PCT). This article reviews PCT for the evaluation of AIS patients.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Isquemia Encefálica/complicações , Angiografia Cerebral , Humanos , Acidente Vascular Cerebral/complicações
2.
Radiol Clin North Am ; 57(6): 1117-1131, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31582039

RESUMO

Various imaging techniques play a role in the diagnosis of CNS vasculopathies, which comprise a heterogeneous group of disorders, including various noninflammatory and inflammatory etiologies. Noninflammatory vasculopathies include entities such as CADASIL, Susac, moyamoya, fibromuscular dysplasia, vasculopathy of connective tissue disorders, and reversible vasoconstriction syndrome. Inflammatory vasculopathies include vasculitides of different vessel sizes, primary angiitis of the CNS, vasculitis of systemic disease, and vasculitis secondary to specific causes. Miscellaneous etiology includes cerebral amyloid angiopathy, which has noninflammatory and inflammatory subtypes. This article discusses important clinical and imaging findings used to distinguish these disorders.


Assuntos
Diagnóstico por Imagem/métodos , Doenças do Sistema Nervoso/diagnóstico por imagem , Doenças Vasculares/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética , Tomografia Computadorizada por Raios X , Ultrassonografia
3.
Pan Afr Med J ; 33: 145, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31558942

RESUMO

Susac syndrome is an autoimmune endothelopathy that affects precapillary arterioles of the brain, retina and inner ear. We report for the first time observations of two patients with Susac syndrome in Senegal.


Assuntos
Encéfalo/irrigação sanguínea , Síndrome de Susac/diagnóstico , Adulto , Orelha Interna/irrigação sanguínea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vasos Retinianos/patologia , Senegal , Síndrome de Susac/fisiopatologia
4.
Psychiatr Danub ; 31(Suppl 3): 357-370, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31488753

RESUMO

Efforts to disclose the mechanisms of transcranial therapeutic electro-magnetic fields (EMF) acting on the brain's cells (Marino, Kibleur) and recently immune cells (Gülöksüz) meet unsolved physiological details of blood vessels, exclusively arterial vasomotion or the non-glial-related former g(lia)-lymphatic flow (Iliff; Liu DX) - now replaced by an astrocytic AQP4-pipeline cooling the brain (Nakada 2014). Here within the convergent dyn4TAM-framework, which had suggested the first mast cell behavioral experiment (Fitzpatrick & Morrow 2017), three intertwined physiological concepts are contributed: A) "autocrinicity" - how flushed, thus absent, autocrine signals integrate external fluidics into cellular computations e.g. on motility: EMFs could increase such absences by targeting e.g. dipole-cytokines; B) a new concept of the arterial wall based on a tangible interpretation of the coronal histology of all arteries as a co-axial pulse-dampening engine (Treviranus 2012). In the brain this engine might provide the quickest cerebral outflow via the Cerebral IntraMUral Reverse Arterial Flow (Treviranus 2018b), while transmitting further forces acting upstream to the paravascular spaces; C) some key roles for mast cells in neuro-psychiatry (Silver & Curley 2013) and their interactive lymphatic and non-luminal vascular routes to the brain dictated by peripheral imprinting as to destiny (Csaba 1987) and destination (Treviranus 2013). Within the skull they might advance against para-arterial upstream currents. Some known causal mediators of the effects of transcranially applied EFMs and puzzling results are then put tentatively in perspective with the above "tangible" models, e.g. by aligning probable induced currents with arterial segments or the new direct meningeal-calvario-myeloid channels. RESULTS: The case for a role of mast cells and diverse flows in transcranial electromagnetic brain therapy seems promising.


Assuntos
Artérias/citologia , Comunicação Autócrina , Encéfalo/irrigação sanguínea , Campos Eletromagnéticos , Sistema Glinfático/fisiologia , Mastócitos/citologia , Humanos
5.
J Comput Assist Tomogr ; 43(5): 697-707, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31490889

RESUMO

OBJECTIVE: To explore the application value of postlabeling delay (PLD) in 3D pseudocontinuous arterial spin-labeled (3D-pcASL) perfusion imaging in normal children and to find the optimal PLD values for children at each age group. METHODS: Five groups of children, with 50 patients in each group, who underwent routine magnetic resonance imaging scans with normal results were included. The patients were stratified according to the following ages: younger than 1 month, more than 1 month to 6 months, more than 6 months to 12 months, more than 1 year to 3 years, more than 3 years to 6 years, and more than 6 years to 18 years. All patients received 3D-pcASL perfusion magnetic resonance scanning. The PLD values were set to 1025, 1525, or 2025 milliseconds. In subjective evaluations, the signal-to-noise ratio (SNR) and cerebral blood flow (CBF) of 3D-pcASL perfusion images under different PLD values were compared and analyzed. RESULTS: For patients in the <1-month group and >1-month to 6-month group, the images were mainly grade A when the PLD value was 1025 milliseconds, which equaled 43 and 46 cases, respectively. The brain CBF values and SNR values were higher than those of the images with PLD values of 1525 and 2025 milliseconds. For patients in the >6-month to 12-month group, >1-year to 3-year group, >3-year to 6-year group, and >6-year to 18-year group, the images were mainly grade A when the PLD value was 1525 milliseconds, which equaled 43, 45, 43, and 46 cases, respectively. The brain CBF values and SNR values were higher than those of the images with PLD values of 1025 and 2025 milliseconds. CONCLUSIONS: The optimal PLD values for 3D-pcASL perfusion imaging are different in children of different ages. The optimal PLD value for infants who are 6 months younger is 1025 milliseconds. The optimal PLD value for children older than 6 months to 18 years is 1525 milliseconds.


Assuntos
Encéfalo/irrigação sanguínea , Artérias Cerebrais/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Imagem por Ressonância Magnética/métodos , Imagem de Perfusão/métodos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Imagem Tridimensional , Lactente , Recém-Nascido , Masculino , Valores de Referência , Marcadores de Spin
6.
Sheng Li Xue Bao ; 71(4): 581-587, 2019 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-31440755

RESUMO

The purpose of this study was to establish a method to record the dynamic process of vascular regeneration and remodeling in rat cerebral ischemic regions. An animal brain window model was established to continuously observe the changes of rat cortical vascular ischemia in vivo, and the model of cerebral ischemia was established by photochemical embolization. Optical coherence tomography (OCT) was performed to record the formation of vascular blockage and the injury and regeneration of small vessels during cerebral ischemia recovery. The results showed that 30 min of laser irradiation could completely block the cortical vessels in rats. Within 24-48 h after ischemia, the degree of brain injury was the greatest, and the number of blood vessels in the ischemic region reached the minimum. Then the blocked blood vessels began to be dredged, and the small blood vessels around the ischemic area began to regenerate. Small blood vessels in the superficial/deep layers of the cortex disappeared significantly after laser irradiation. During 10 d after ischemia, the blocked blood vessels were gradually dredged and recovered. On the 10th day after laser irradiation, a large number of neovascularization appeared in the superficial layer of cortex, but the deep vessels did not recover. These results indicate that the method established in this study can observe the changes of blood vessel in cerebral ischemic region continuously, which lays a foundation for further quantitative study on the dynamics of embolized blood vessels and peripheral capillaries during the recovery of cerebral ischemia.


Assuntos
Isquemia Encefálica , Encéfalo/irrigação sanguínea , Córtex Cerebral/irrigação sanguínea , Regeneração , Animais , Ratos
7.
Top Magn Reson Imaging ; 28(4): 205-212, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31385900

RESUMO

Blood oxygenation level-dependent (BOLD) imaging is gaining traction in the clinical realm as a measure for quantifying changes in regional blood flow in response to external stimuli. Through the evoked signal changes that are a consequence of hemoglobin's intrinsic paramagnetic properties, this technique allows for the statistical mapping of brain regions associated with a given task, which has broad applications in preneurosurgical planning for tumor resection. From an acquisition perspective, collection of BOLD data most commonly requires the use of echo planar imaging readout schemes. These sequences are currently widely available on most clinical scanners and at various field strengths. However, while the BOLD acquisition protocol is relatively straightforward, additional hardware and rigorous image processing are needed to correlate the time-dependent signal changes associated with a specific and well defined task. This manuscript will provide the necessary information to detail the physiologic underpinning of acquiring BOLD sensitized images and the important technical aspects of processing the data for use in a surgical environment.


Assuntos
Mapeamento Encefálico/métodos , Neoplasias Encefálicas/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Neoplasias Encefálicas/cirurgia , Imagem Ecoplanar/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética/métodos , Oxigênio/sangue , Cuidados Pré-Operatórios/métodos
8.
Top Magn Reson Imaging ; 28(4): 225-233, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31385902

RESUMO

Clinical use of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) is a relatively new phenomenon, with only about 3 decades of collective experience. Nevertheless, task-based BOLD fMRI has been widely accepted for presurgical planning, over traditional methods, which are invasive and at times perilous. Many studies have demonstrated the ability of BOLD fMRI to make substantial clinical impact with respect to surgical planning and preoperative risk assessment, especially to localize the eloquent motor and visual areas. Reproducibility and repeatability of language fMRI are important in the assessment of its clinical usefulness. There are national efforts currently underway to standardize language fMRI. The American Society of Functional Neuroradiology (ASFNR) has recently provided guidelines on fMRI paradigm algorithms for presurgical language assessment for language lateralization and localization. In this review article, we provide a comprehensive overview of current standards of language fMRI mapping and its reproducibility.


Assuntos
Encefalopatias/diagnóstico por imagem , Linguagem , Imagem por Ressonância Magnética/métodos , Algoritmos , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Encéfalo/cirurgia , Encefalopatias/sangue , Encefalopatias/fisiopatologia , Encefalopatias/cirurgia , Mapeamento Encefálico/métodos , Humanos , Oxigênio/sangue , Cuidados Pré-Operatórios/métodos , Reprodutibilidade dos Testes
9.
BMC Neurol ; 19(1): 206, 2019 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-31443692

RESUMO

BACKGROUND: Subcortical ischemic vascular dementia (SIVD) is very common among the older people, but has no approved treatment. Preclinical trials show that remote ischemic conditioning (RIC) reduces recurrence of ischemic stroke. We hypothesize that RIC may also be an effective therapy for patients with SIVD. METHODS: Thirty-seven consecutive SIVD cases were enrolled in this randomized control study. Eighteen RIC patients underwent five brief cycles of conditioning (bilateral upper limb compression at 200 mmHg) followed by reperfusion twice daily over 6 consecutive months. Nineteen control patients underwent the same process, but at a pressure of 60 mmHg which caused no restriction on the blood flow of the upper limb. The primary outcome measures were changes in neuropsychological assessments. The secondary outcomes included the changes in high-sensitive C-reactive protein (hs-CRP) concentration, white matter lesion volume (WMLV), diffusion tension imaging (DTI) metrics of white matter. All data were collected at baseline and follow-up. RESULTS: A significant treatment difference favoring RIC at 6 months was observed on performance of Hopkins Verbal Learning Test-Revised (HVLT-R), Controlled Oral Word Association Test (COWAT), Trail Making Test A and B (TMT-A & TMT-B), and Judgment of Line Orientation (JLO) (p < 0.05). The control group did not show much improvement after the treatment, and only with a slight change in HVLT-R and TMT-R (p < 0.05). Covariance analysis of efficacy between the two groups suggested that RIC patients performed better on JLO than control patients at the 6-month follow-up (RIC 23.10 vs. control 18.56; p = 0.013). Although DTI metrics were comparable, Hs-CRP levels and WMLV in RIC patients showed a declining trend. CONCLUSIONS: Over the 6-month treatment period, we found that RIC was safe and effective for improving cognitive function in SIVD patients. TRIAL REGISTRATION: Clinical Trial Registration ( http://www.clinicaltrials.gov ), Unique identifier: NCT03022149; Retrospectively registered; Date of registration: January 16, 2017.


Assuntos
Encéfalo/irrigação sanguínea , Cognição , Demência Vascular , Precondicionamento Isquêmico/métodos , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , Encéfalo/fisiopatologia , Demência Vascular/patologia , Demência Vascular/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Extremidade Superior/fisiopatologia
10.
Pharm Res ; 36(10): 141, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31367840

RESUMO

PURPOSE: The purpose of the present study was to investigate changes of blood-brain barrier (BBB) and brain parenchymal protein expression due to type II diabetes mellitus (T2DM) induced by a high-fat diet (HFD) by using SWATH-based quantitative proteomics. METHODS: Mice were fed a HFD for 2 or 10 weeks, and then SWATH-based quantitative proteomic analysis, western blot analysis, immunohistochemistry and functional transport studies were performed. RESULTS: In brain capillaries, expression levels of BBB transporters (Glut1, P-glycoprotein) and tight-junction proteins (claudin-5, occludin) were significantly reduced in HFD mice at 2 weeks, but recovered to the levels in the normal diet (ND) group at 10 weeks. P-glycoprotein function at the BBB was reduced at 2 weeks. In the cerebral cortex and hippocampus, neurofilament, which is important for neuronal function, was decreased in HFD mice at 2 weeks, but recovered at 10 weeks. CONCLUSION: Our results suggest that changes in the status of insulin resistance influence expression of BBB transporters, which in turn may alter the expression of cognitive function-related proteins.


Assuntos
Encéfalo/metabolismo , Dieta Hiperlipídica/efeitos adversos , Resistência à Insulina , Insulina/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/irrigação sanguínea , Capilares/metabolismo , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Filamentos Intermediários/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Proteômica , Proteínas de Junções Íntimas/metabolismo
11.
Aquat Toxicol ; 214: 105224, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31255847

RESUMO

Polybrominated diphenyl ethers (PBDEs) are distributed throughout the environment. Despite a moratorium on their use, concentrations of PBDEs in the atmosphere and in residential environments remain high due to their persistence. The environmental health risks remain concerning and one of the major adverse effects is neurodevelopmental toxicity. However, the early response and effects of PBDEs exposure on the developing brain remain unknown. In the present study, we investigated the impacts of 2,2',4,4',5-pentabrominated diphenyl ether (BDE-99) on vascular growth and vascular barrier function with an emphasis on cerebral blood vessels, in the early life stages, using a zebrafish model. No general toxicity was observed in exposing zebrafish larvae to 0-0.5 µM BDE-99 at 72 hpf. BDE-99 exposure resulted in neither general toxicity nor pronounced developmental impairment in somatic blood vessels, including intersegmental vessels (ISV) and common cardinal veins (CCV). Meanwhile, both 0.05 µM and 0.5 µM of BDE-99 reduced cerebrovascular density as well as down-regulation of VEGFA and VEGFR2 in the head. In addition, BDE-99 exposure increased vascular leakage, both in cerebral and truncal vasculature at 72 hpf. The accentuated vascular permeability was observed in the head. The mRNA levels of genes encoding tight junction molecules decreased in the BDE-99-exposed larvae, and more robust reductions in Cldn5, Zo1 and Jam were detected in the head than in the trunk. Moreover, proinflammatory factors including TNF-α, IL-1ß and ICAM-1 were induced, and the expression of neurodevelopment-related genes was suppressed in the head following BDE-99 exposure. Taken together, these results reveal that developmental exposure to BDE-99 impedes cerebrovascular growth and disturbs vascular barrier formation. The cerebral vasculature in developing zebrafish, a more sensitive target for BDE-99, may be a promising tool for the assessment of the early neurodevelopmental effects due to PBDEs exposure.


Assuntos
Vasos Sanguíneos/efeitos dos fármacos , Exposição Ambiental , Éteres Difenil Halogenados/toxicidade , Peixe-Zebra/crescimento & desenvolvimento , Animais , Encéfalo/irrigação sanguínea , Encéfalo/crescimento & desenvolvimento , Permeabilidade Capilar/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Inflamação/genética , Inflamação/patologia , Larva/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/genética
12.
Life Sci ; 232: 116599, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31247210

RESUMO

AIM: Ischemia/reperfusion (I/R) injury is the major cause of neurological deficit following stroke. Our previous study showed neuroprotective effects of hispidulin against cerebral ischemia reperfusion injury (IRI). In this study, we further examined the involvement of pyroptosis in this neuroprotective function. MATERIALS AND METHODS: IRI was simulated in a rat model by middle cerebral artery occlusion (MCAO) surgery, and the animals were treated with different doses of hispidulin. The neurological function of the rats was evaluated by the neural function defect score (NFDS), balance beam test and limb placement test. The infarct volume and brain water content were measured 72 h following IRI. Neuronal cell survival and pyroptosis in the ischemic cortex were respectively detected by Nissl staining and TUNEL assay. The relative expression of pyroptosis markers was determined by qRT-PCR, Western blotting and ELISA as appropriate. IRI was simulated in vitro in primary cerebral astrocytes using the OGD/R procedure. AMPKα was blocked genetically or pharmacologically using siRNA and compound C respectively. CCK-8 and LDH release assays were performed using suitable kits. RESULTS: Hispidulin improved the neurological symptoms of the rats after IRI, in addition to decreasing the infarct size and brain edema. Mechanistically, hispidulin exerted its neuroprotective effects in vivo and in vitro by suppressing NLRP3-mediated pyroptosis by modulating the AMPK/GSK3ß signaling pathway. CONCLUSION: Hispidulin is a neuroprotective agent with clinical potential against IR-induced neurological injury.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Flavonas/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Apoptose/efeitos dos fármacos , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Sobrevivência Celular/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/metabolismo , Infarto da Artéria Cerebral Média/tratamento farmacológico , Masculino , Proteína 3 que Contém Domínio de Pirina da Família NLR/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Fármacos Neuroprotetores/farmacologia , Piroptose/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Transdução de Sinais/efeitos dos fármacos , Acidente Vascular Cerebral/tratamento farmacológico
13.
Zh Nevrol Psikhiatr Im S S Korsakova ; 119(3. Vyp. 2): 24-36, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31184622

RESUMO

A comprehensive assessment of brain perfusion data in connection with the Hemorrhagic Transformation Index (HTI) score to predict hemorrhagic transformation (HT) in acute ischemic stroke (AIS) patients. MATERIAL AND METHODS: Based on propensity score matching, the authors selected retrospectively 21 case-control pairs from 71 consecutive patients with AIS in the middle cerebral artery territory. Brain computed tomography (CT) perfusion data with blood-brain barrier permeability assessment were obtained in all patients within 12 h after the onset. The infarct core (IC) and penumbra were evaluated with mean transit time (MTT), cerebral blood volume (CBV), cerebral blood flow (CBF), and permeability surface-area product (PS). The outcome was any HT on a follow-up brain CT scan within 2 weeks after the onset. RESULTS: The Firth logistic regression analysis showed that PS was an independent HT predictor in the IC (odds ratio, 8; 95% confidence interval (CI), 1.32-48.4; p=0.023). The cut-off value was 2.88 mL/100 g/min (95% normal-based CI (NB-CI): 2.41-3,34) with sensitivity 0,95 (95% NB-CI: 0.87-1.0), specificity 1 (95% NB-CI: 0.95-1.0), and area under ROC-curve 0.98 (95% NB-CI: 0.94-1.0). However, no independent HT predictor was found in the penumbra. The generalized linear model analysis revealed that the HTI score was a predictor of CBV, CBF, and PS in the IC and penumbra. As the HT risk grew simultaneously with the HTI score increment, the CBV and CBF became low with a substantial PS rise in the IC; the IC size tended to increase as well. In the penumbra, there was a progressive CBF reduction with a significant CBV and PS climb. At the same time, the MTT-CBV mismatch shrank. CONCLUSION: The IC is more likely to be the site of HT. The PS is an independent HT predictor in the IC. The HTI score can predict the HT probability as well as the brain perfusion data. As the HT risk increases, the perfusion disorders become worse in the IC and penumbra.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Encéfalo/irrigação sanguínea , Isquemia Encefálica/diagnóstico por imagem , Circulação Cerebrovascular , Humanos , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X
14.
Int J Nanomedicine ; 14: 3571-3582, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31213799

RESUMO

Background: In vivo fluorescence imaging in the second near-infrared (NIR-II, 1000-1700 nm) window using organic fluorophores has great advantages, but generally suffers from a relatively low fluorescence quantum yield (mostly less than 2%). In this study, organic nanoparticles (L1013 NPs) with a high fluorescence quantum yield (9.9%) were systhesized for in vivo imaging. Methods: A molecule (BTPPA) with donor-acceptor-donor structure and aggregation-induced emission enabling moieties was prepared. BTPPA molecules were then encapsulated into nanoparticles (L1013 NPs) using a nanoprecipitation method. The L1013 NPs were intravenously injected into the mice (including normal, stroke and tumor models) for vascular and tumor imaging. Results: L1013 NPs excited at 808 nm exhibit NIR-II emission with a peak at 1013 nm and an emission tail extending to 1400 nm. They have a quantum yield of 9.9% and also show excellent photo/colloidal stabilities and negligible in vitro and in vivo toxicity. We use L1013 NPs for noninvasive real-time visualization of mouse hindlimb and cerebral vessels (including stroke pathology) under a very low power density (4.6-40 mW cm‒2) and short exposure time (40-100 ms). Moreover, L1013 NPs are able to localize tumor pathology, with a tumor-to-normal tissue ratio of 11.7±1.3, which is unusually high for NIR-II fluorescent imaging through passive targeting strategy. Conclusion: L1013 NPs demonstrate the potential for a range of clinical applications, especially for tumor surgery.


Assuntos
Corantes Fluorescentes/química , Nanopartículas/química , Imagem Óptica/métodos , Espectroscopia de Luz Próxima ao Infravermelho , Animais , Vasos Sanguíneos/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Modelos Animais de Doenças , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/farmacocinética , Camundongos Endogâmicos C57BL , Nanopartículas/toxicidade , Nanopartículas/ultraestrutura , Acidente Vascular Cerebral/diagnóstico por imagem , Distribuição Tecidual
15.
J Stroke Cerebrovasc Dis ; 28(8): 2079-2097, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31151839

RESUMO

Since the term "lacune" was adopted in the 1800s to describe infarctions from cerebral small vessels, their underlying pathophysiological basis remained obscure until the 1960s when Charles Miller Fisher performed several autopsy studies of stroke patients. He observed that the vessels displayed segmental arteriolar disorganization that was associated with vessel enlargement, hemorrhage, and fibrinoid deposition. He coined the term "lipohyalinosis" to describe the microvascular mechanism that engenders small subcortical infarcts in the absence of a compelling embolic source. Since Fisher's early descriptions of lipohyalinosis and lacunar stroke (LS), there have been many advancements in the understanding of this disease process. Herein, we review lipohyalinosis as it relates to modern concepts of cerebral small vessel disease (cSVD). We discuss clinical classifications of LS as well as radiographic definitions based on modern neuroimaging techniques. We provide a broad and comprehensive overview of LS pathophysiology both at the vessel and parenchymal levels. We also comment on the role of biomarkers, the possibility of systemic disease processes, and advancements in the genetics of cSVD. Lastly, we assess preclinical models that can aid in studying LS disease pathogenesis. Enhanced understanding of this highly prevalent disease will allow for the identification of novel therapeutic targets capable of mitigating disease sequelae.


Assuntos
Encéfalo/irrigação sanguínea , Artérias Cerebrais/fisiopatologia , Acidente Vascular Cerebral Lacunar/fisiopatologia , Animais , Biomarcadores/metabolismo , Biópsia , Artérias Cerebrais/metabolismo , Artérias Cerebrais/patologia , Circulação Cerebrovascular , Predisposição Genética para Doença , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Neuroimagem/métodos , Fenótipo , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco , Acidente Vascular Cerebral Lacunar/diagnóstico , Acidente Vascular Cerebral Lacunar/genética , Acidente Vascular Cerebral Lacunar/história , Remodelação Vascular
16.
BMC Neurol ; 19(1): 121, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31185944

RESUMO

BACKGROUND: No longitudinal, long-term, follow-up studies have explored the association between presence and severity of variations in extracranial venous anatomy, and clinical outcomes in patients with multiple sclerosis (MS). OBJECTIVE: This prospective 5-year follow-up study assessed the relationship of variations in extracranial venous anatomy, indicative of chronic cerebrospinal venous insufficiency (CCSVI) on Doppler sonography, according to the International Society for Neurovascular Disease (ISNVD) proposed consensus criteria, with clinical outcomes and disease progression in MS patients. METHODS: 90 MS patients (52 relapsing-remitting, RRMS and 38 secondary-progressive, SPMS) and 38 age- and sex-matched HIs were prospectively followed for 5.5 years. Extracranial and transcranial Doppler-based venous hemodynamic assessment was conducted at baseline and follow-up to determine the extent of variations in extracranial venous anatomy. Change in Expanded Disability Status Scale (∆EDSS), development of disability progression (DP) and annualized relapse rate (ARR) were assessed. RESULTS: No significant differences were observed in MS patients, based on their presence of variations in extracranial venous anatomy at baseline or at the follow-up, in ∆EDSS, development of DP or ARR. While more MS patients had ISNVD CCSVI criteria fulfilled at baseline compared to HIs (58% vs. 37%, p = 0.03), no differences were found at the 5-year follow-up (61% vs. 56%, p = 0.486). DISCUSSION: This is the longest follow-up study assessing the longitudinal relationship between the presence of variations in extracranial venous anatomy and clinical outcomes in MS patients. CONCLUSION: The presence of variations in extracranial venous anatomy does not influence clinical outcomes over the 5-year follow-up in MS patients.


Assuntos
Encéfalo/irrigação sanguínea , Esclerose Múltipla , Medula Espinal/irrigação sanguínea , Insuficiência Venosa/epidemiologia , Adulto , Veia Ázigos/anormalidades , Estudos de Casos e Controles , Circulação Cerebrovascular , Progressão da Doença , Feminino , Seguimentos , Humanos , Veias Jugulares/anormalidades , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva
17.
Int J Mol Sci ; 20(11)2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151154

RESUMO

Cognitive impairment and dementia are recognized as major threats to public health. Many studies have shown the important role played by challenges to the cerebral vasculature and the neurovascular unit. To investigate the structural and functional characteristics of the brain, MRI has proven an invaluable tool for visualizing the internal organs of patients and analyzing the parameters related to neuronal activation and blood flow in vivo. Different strategies of imaging can be combined to obtain various parameters: (i) measures of cortical and subcortical structures (cortical thickness, subcortical structures volume); (ii) evaluation of microstructural characteristics of the white matter (fractional anisotropy, mean diffusivity); (iii) neuronal activation and synchronicity to identify functional networks across different regions (functional connectivity between specific regions, graph measures of specific nodes); and (iv) structure of the cerebral vasculature and its efficacy in irrorating the brain (main vessel diameter, cerebral perfusion). The high amount of data obtainable from multi-modal sources calls for methods of advanced analysis, like machine-learning algorithms that allow the discrimination of the most informative features, to comprehensively characterize the cerebrovascular network into specific and sensitive biomarkers. By using the same techniques of human imaging in pre-clinical research, we can also investigate the mechanisms underlying the pathophysiological alterations identified in patients by imaging, with the chance of looking for molecular mechanisms to recover the pathology or hamper its progression.


Assuntos
Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Imagem por Ressonância Magnética , Neuroimagem , Animais , Biomarcadores , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Circulação Cerebrovascular , Disfunção Cognitiva/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Humanos , Processamento de Imagem Assistida por Computador , Aprendizado de Máquina , Angiografia por Ressonância Magnética , Imagem por Ressonância Magnética/métodos , Rede Nervosa/diagnóstico por imagem , Neuroimagem/métodos , Melhoria de Qualidade , Pesquisa Médica Translacional , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
18.
A A Pract ; 12(11): 390-392, 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31162164

RESUMO

Regional cerebral tissue saturation monitoring is frequently used in patients on mechanical cardiac assist devices with the intention to promptly detect critical imbalances between cerebral oxygen delivery and oxygen extraction and ultimately circumvent permanent brain injury. We report a case where an intraparenchymal bleed in the supply zone of the middle cerebral artery-followed by severe hemispherical brain edema, leading to life-threatening intracranial hypertension-escaped cerebral oximetry monitoring using near-infrared spectroscopy. Potential explanations for our observation, as well as the specific limitations of these devices, are discussed.


Assuntos
Edema Encefálico/terapia , Encéfalo/irrigação sanguínea , Hemorragia Cerebral/terapia , Oxigênio/sangue , Edema Encefálico/metabolismo , Hemorragia Cerebral/metabolismo , Oxigenação por Membrana Extracorpórea , Feminino , Humanos , Pessoa de Meia-Idade , Oximetria , Espectroscopia de Luz Próxima ao Infravermelho
19.
Adv Mater ; 31(30): e1902504, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31169334

RESUMO

Diagnostics of cerebrovascular structures and microscopic tumors with intact blood-brain barrier (BBB) significantly contributes to timely treatment of patients bearing neurological diseases. Dual NIR-II fluorescence and photoacoustic imaging (PAI) is expected to offer powerful strength, including good spatiotemporal resolution, deep penetration, and large signal-to-background ratio (SBR) for precise brain diagnostics. Herein, biocompatible and photostable conjugated polymer nanoparticles (CP NPs) are reported for dual-modality brain imaging in the NIR-II window. Uniform CP NPs with a size of 50 nm are fabricated from microfluidics devices, which show an emission peak at 1156 nm with a large absorptivity of 35.2 L g-1 cm-1 at 1000 nm. The NIR-II fluorescence imaging resolves hemodynamics and cerebral vasculatures with a spatial resolution of 23 µm at a depth of 600 µm. The NIR-II PAI enables successful noninvasive mapping of deep microscopic brain tumors (<2 mm at a depth of 2.4 mm beneath dense skull and scalp) with an SBR of 7.2 after focused ultrasound-induced BBB opening. This study demonstrates that CP NPs are promising contrast agents for brain diagnostics.


Assuntos
Vasos Sanguíneos/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Corantes Fluorescentes/química , Animais , Materiais Biocompatíveis/química , Barreira Hematoencefálica/metabolismo , Encéfalo/irrigação sanguínea , Neoplasias Encefálicas/irrigação sanguínea , Linhagem Celular Tumoral , Corantes Fluorescentes/administração & dosagem , Humanos , Raios Infravermelhos , Camundongos , Camundongos Nus , Nanopartículas/química , Imagem Óptica/métodos , Permeabilidade , Técnicas Fotoacústicas/métodos , Polímeros/química
20.
Khirurgiia (Mosk) ; (5): 57-63, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31169820

RESUMO

AIM: To study the effectiveness of intraoperative administration of Cytoflavine for the prevention of ischemic brain injury during cerebral aneurysm (CA) clipping with temporary occlusion of the leading artery under general anesthesia. MATERIAL AND METHODS: The prospective cohort single-center study included 40 patients with CA ( the main group - 27 patients with intraoperative administration of cytoflavine; the comparison group -13 patients without use of cytoflavine), who underwent aneurism clipping with temporary occlusion of the afferent artery. We assesed the intraoperative state of the brain, the time of awakening and extubation of patients after surgery, neurological deficit and local ischemic changes in the area of surgery according to the CT of the brain in the early postoperative period, resuscitation bed-day and the relationship of these indicators with the duration of temporary occlusion of the afferent artery in the selected groups of patients. RESULTS: In intergroup comparison, patients of the main group treated with intraoperative cytoflavin showed a reduction in the time of awakening (p=0.013) and the time of extubation (p=0.01) both with temporary occlusion of the afferent artery and in patients without temporary occlusion (p<0.05). The duration of resuscitation bed-day decreased in the main group of patients receiving intraoperatively cytoflavine (p=0.01), as well as in patients in the comparison group without temporary occlusion (p<0.05). CONCLUSION: Temporary occlusion of the afferent artery with short intervals of vessel occlusion in combination with intraoperative intravenous administration of cytoflavine expands the tolerability to artery occlusion in patients operated in the 'cold' period, reduces the possibility of neurological deficit, reduces the recovery period and resuscitation bed-day after surgical clipping CA.


Assuntos
Lesões Encefálicas/prevenção & controle , Isquemia Encefálica/fisiopatologia , Encéfalo/irrigação sanguínea , Mononucleotídeo de Flavina/administração & dosagem , Inosina Difosfato/administração & dosagem , Aneurisma Intracraniano/fisiopatologia , Fármacos Neuroprotetores/administração & dosagem , Procedimentos Neurocirúrgicos/efeitos adversos , Niacinamida/administração & dosagem , Succinatos/administração & dosagem , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Encéfalo/cirurgia , Lesões Encefálicas/etiologia , Lesões Encefálicas/fisiopatologia , Lesões Encefálicas/cirurgia , Isquemia Encefálica/etiologia , Isquemia Encefálica/cirurgia , Combinação de Medicamentos , Mononucleotídeo de Flavina/farmacologia , Humanos , Inosina Difosfato/farmacologia , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/cirurgia , Cuidados Intraoperatórios , Fármacos Neuroprotetores/farmacologia , Procedimentos Neurocirúrgicos/métodos , Niacinamida/farmacologia , Estudos Prospectivos , Succinatos/farmacologia , Técnicas de Sutura
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