Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Filtros adicionais











Tipo de estudo
Intervalo de ano
1.
J Nanosci Nanotechnol ; 20(2): 692-700, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383064

RESUMO

Fluorescent bimetallic Au-Ag nanoclusters (Au-AgNCs) were found to exhibit oxidase-like activity and could catalyze the oxidation of 3,3',5,5' tetramethylbenzidine (TMB) to oxTMB. On the basis of this property, we assembled a fluorescent nanoplatform as a turn-on probe for sensing mercury (II) ions (Hg2+) through the inner-filter effect (IFE). Au-AgNCs and oxTMB were chosen as IFE absorber and fluorophore pair for the first time. In the absence of Hg2+, the Au-AgNCs absorption band well. Covered the fluorescence emission band of oxTMB, and as a result, the fluorescence of oxTMB was reduced. In the presence of Hg2+, Hg2+ was reduced to Hg0 by extra BSA in Au-AgNCs probe system and anchored on the surface of Au-AgNCs. The absorption intensity for Au-AgNCs then decreased at 418 nm, resulting in the recovery of fluorescence from oxTMB. The formed Au-Hg thin amalgam layer obviously enhanced the oxidase-like activity of Au-AgNCs as well as hindered the IFE activity between Au-AgNCs and oxTMB. Therefore, based on the Hg2+ stimulating oxidaselike properties of Au-AgNCs, a fluorometric assay for determination of Hg2+ was developed in this study. The proposed sensing strategy showed a linear range from 10 nM to 500 nM, with ultralow LOD of ~0.7 nM for Hg2+. Moreover, the detection probe system was stable over a wide pH range, making it able to be applied in complex sample systems. We have successfully demonstrated the detection of Hg2+ in tap water samples. The fluorescent assay reported here, for sensitive and selective determination of Hg2+, may find great application in multiple areas, such as environmental and pharmaceutical analysis.

2.
Brain ; 141(12): 3457-3471, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30445590

RESUMO

Depression increases the conversion risk from amnestic mild cognitive impairment to Alzheimer's disease with unknown mechanisms. We hypothesize that the cumulative genomic risk for major depressive disorder may be a candidate cause for the increased conversion risk. Here, we aimed to investigate the predictive effect of the polygenic risk scores of major depressive disorder-specific genetic variants (PRSsMDD) on the conversion from non-depressed amnestic mild cognitive impairment to Alzheimer's disease, and its underlying neurobiological mechanisms. The PRSsMDD could predict the conversion from amnestic mild cognitive impairment to Alzheimer's disease, and amnestic mild cognitive impairment patients with high risk scores showed 16.25% higher conversion rate than those with low risk. The PRSsMDD was correlated with the left hippocampal volume, which was found to mediate the predictive effect of the PRSsMDD on the conversion of amnestic mild cognitive impairment. The major depressive disorder-specific genetic variants were mapped into genes using different strategies, and then enrichment analyses and protein-protein interaction network analysis revealed that these genes were involved in developmental process and amyloid-beta binding. They showed temporal-specific expression in the hippocampus in middle and late foetal developmental periods. Cell type-specific expression analysis of these genes demonstrated significant over-representation in the pyramidal neurons and interneurons in the hippocampus. These cross-scale neurobiological analyses and functional annotations indicate that major depressive disorder-specific genetic variants may increase the conversion from amnestic mild cognitive impairment to Alzheimer's disease by modulating the early hippocampal development and amyloid-beta binding. The PRSsMDD could be used as a complementary measure to select patients with amnestic mild cognitive impairment with high conversion risk to Alzheimer's disease.

3.
BMC Neurol ; 17(1): 164, 2017 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-28841844

RESUMO

BACKGROUND: Acute autonomic neuropathy (AAN) is rare disorder with anecdotal report, especially for childhood onset patients. Misdiagnosis or delays in treatment can always be found in clinical practice. We conducted this study to give a description of the manifestations and treatment of AAN in children and therefore help clinicians to make the accurate diagnosis early so that the prognosis of the patients can be improved. METHODS: A systematic record from 3 clinical centers was used to identify 11 subject, 3 males and 8 females, with clinical diagnosed AAN. RESULT: The age ranged from 2 years and 4 months to 14 years and 6 months (mean, 9 ± 3.6 years old) and the course from onset to diagnosis ranged from 7 days to 8 months. All children shared prominent initial symptoms, 7 with frequent vomiting and 4 with motor dysfunctions. The condition of 9 patients improved after treatment of IVIg and intravenous glucocorticoid. CONCLUSION: The clinical manifestations of AAN are diverse, generalized, and non-specific. Gastrointestinal disorders were the most common initial symptoms. Symptoms of gastrointestinal system and abnormal secretion of glands were severe and more common than other symptoms. The mechanism of AAN remains unknown. Although IVIg and intravenous glucocorticoid can be used in clinical practice, there is still no treatment recommendation and further study is needed.


Assuntos
Doenças do Sistema Nervoso Autônomo , Gastroenteropatias , Criança , Pré-Escolar , Feminino , Humanos , Masculino
4.
Cereb Cortex ; 27(11): 5211-5221, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27664968

RESUMO

There exist gender differences in the modulation of catechol-O-methyltransferase (COMT) Val158Met polymorphism on cognitive performance; however, the underlying gene-anatomy-cognition pathways remain unknown. Here we hypothesize that prefrontal volume may mediate the modulation of COMT Val158Met polymorphism on interference resolution capacity in a gender-dependent manner. In 261 healthy young human subjects (143 males and 118 females), a 2-way analysis of variance showed a COMT × gender interaction (P = 0.023) on interference resolution capacity. Val/Val subjects performed worse in Stroop interference test than Met/Met subjects only in males (P = 0.028). Voxel-wise analysis in the whole brain also exhibited a COMT × gender interaction on gray matter volume (GMV) in the left lateral frontal pole (FP). Val/Val male individuals exhibited significantly decreased GMV in the left lateral FP than Val/Met (P = 0.003) and Met/Met (P = 0.006) male carriers. Mediation analysis revealed that the GMV of the left lateral FP mediated the association between COMT polymorphism and interference resolution in males. These findings provide a gene-anatomy-cognition pathway to describe how COMT Val158Met polymorphism affects interference resolution capacity via modulating the prefrontal GMV in healthy male subjects.


Assuntos
Catecol O-Metiltransferase/genética , Função Executiva , Inibição (Psicologia) , Polimorfismo de Nucleotídeo Único , Córtex Pré-Frontal/diagnóstico por imagem , Análise de Variância , Grupo com Ancestrais do Continente Asiático/genética , Função Executiva/fisiologia , Feminino , Lateralidade Funcional , Substância Cinzenta/anatomia & histologia , Substância Cinzenta/diagnóstico por imagem , Humanos , Imagem por Ressonância Magnética , Masculino , Atividade Motora/fisiologia , Tamanho do Órgão , Córtex Pré-Frontal/anatomia & histologia , Fatores Sexuais , Teste de Stroop , Adulto Jovem
5.
Brain Imaging Behav ; 11(4): 1029-1036, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27468855

RESUMO

Blindness primarily induces structural alteration in the primary visual cortex (V1). Some studies have found that the early blind subjects had a thicker V1 compared to sighted controls, whereas late blind subjects showed no significant differences in the V1. This implies that the age of blindness onset may exert significant effects on the development of cortical thickness of the V1. However, no previous research used a trajectory of the age of blindness onset-related changes to investigate these effects. Here we explored this issue by mapping the cortical thickness trajectory of the V1 against the age of blindness onset using data from 99 blind individuals whose age of blindness onset ranged from birth to 34 years. We found that the cortical thickness of the V1 could be fitted well with a quadratic curve in both the left (F = 11.59, P = 3 × 10-5) and right hemispheres (F = 6.54, P = 2 × 10-3). Specifically, the cortical thickness of the V1 thinned rapidly during childhood and adolescence and did not change significantly thereafter. This trend was not observed in the primary auditory cortex (A1), primary motor cortex (M1), or primary somatosensory cortex (S1). These results provide evidence that an onset of blindness before adulthood significantly affects the cortical thickness of the V1 and suggest a critical period for cortical development of the human V1.


Assuntos
Cegueira/diagnóstico por imagem , Córtex Visual/diagnóstico por imagem , Córtex Visual/crescimento & desenvolvimento , Adulto , Idade de Início , Análise de Variância , Córtex Auditivo/diagnóstico por imagem , Córtex Auditivo/crescimento & desenvolvimento , Córtex Auditivo/patologia , Cegueira/epidemiologia , Cegueira/patologia , Cegueira/fisiopatologia , Feminino , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética , Masculino , Córtex Motor/diagnóstico por imagem , Córtex Motor/crescimento & desenvolvimento , Córtex Motor/patologia , Tamanho do Órgão , Córtex Somatossensorial/diagnóstico por imagem , Córtex Somatossensorial/crescimento & desenvolvimento , Córtex Somatossensorial/patologia , Córtex Visual/patologia
6.
Front Neuroanat ; 9: 50, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25964743

RESUMO

Connectivity-based parcellation using diffusion MRI has been extensively used to parcellate subcortical areas and the association cortex. Connectivity profiles are vital for connectivity-based parcellation. Two categories of connectivity profiles are generally utilized, including global connectivity profiles, in which the connectivity information is from the seed to the whole brain, and long connectivity profiles, in which the connectivity information is from the seed to other brain regions after excluding the seed. However, whether global or long connectivity profiles should be applied in parcellating the primary cortex utilizing connectivity-based parcellation is unclear. Many sources of evidence have indicated that the primary cerebral cortices are composed of structurally and functionally distinct subregions. Because the primary cerebral cortices are rich in local anatomic hierarchical connections and possess high degree of local functional connectivity profiles, we proposed that local connectivity profiles, that is the connectivity information within a seed region of interest, might be used for parcellating the primary cerebral cortices. In this study, the global, long, and local connectivity profiles were separately used to parcellate the bilateral M1, A1, S1, and V1. We found that results using the three profiles were all quite consistent with reported cytoarchitectonic evidence. More importantly, the results using local connectivity profiles showed less inter-subject variability than the results using the other two, a finding which suggests that local connectivity profiles are superior to global and long connectivity profiles for parcellating the primary cerebral cortices. This also implies that, depending on the characteristics of specific areas of the cerebral cortex, different connectivity profiles may need to be adopted to parcellate different areas.

7.
Brain Inj ; 29(5): 651-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25625519

RESUMO

PRIMARY OBJECTIVE: Neuroglobin (NGB) is a known neuroprotector and is up-regulated after ischaemia-hypoxia brain damage. However, no studies have investigated NGB levels after ischaemic pre-conditioning and middle cerebral artery occlusion (MCAO). METHODS AND PROCEDURES: This study subjected rats to different ischaemic pre-conditioning and MCAO regimens and assayed NGB levels in the hippocampus, cortex and hypothalamus by immunohistochemistry, quantitative polymerase chain reaction (PCR) and western blot. MAIN OUTCOMES AND RESULTS: After 30 minutes of ischaemic pre-conditioning, the number of NGB-positive cells and NGB levels in the hippocampus, cortex and hypothalamus were increased with longer reperfusion times, peaked at 24-hours reperfusion and slightly decreased at 48-hours reperfusion. Similarly, the mRNA and protein expression levels of NGB were also up-regulated; they peaked at 24-hours reperfusion and slightly decreased at 48-hours reperfusion. CONCLUSIONS: NGB may regulate neuroprotection against ischaemia and hypoxia-mediated brain damage after ischaemic pre-conditioning. The results provide additional evidence supporting the utility of ischaemic pre-conditioning and help elucidate its potential regulatory mechanism.


Assuntos
Globinas/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Precondicionamento Isquêmico/métodos , Proteínas do Tecido Nervoso/metabolismo , Animais , Feminino , Hipocampo/metabolismo , Masculino , Modelos Animais , Neuroglobina , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Regulação para Cima
8.
Zhongguo Dang Dai Er Ke Za Zhi ; 13(4): 340-3, 2011 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-21507308

RESUMO

OBJECTIVE: To explore the signal transduction pathway mediated by thrombopoietin (TPO) in the inflammation model of microglia induced by lipopolysaccharide (LPS). METHODS: The inflammation model of microglia BV2 cells was prepared by LPS of 0.5 and 1.0 µg/mL stimulation. The expression of TPO and ERK mRNA in BV2 cells was detected by real time quantitative PCR. Western blot was used to evaluate the expression of TPO and ERK protein in BV2 cells. TPO and IL-6 contents in the culture supernatant fluid were measured using ELISA. RESULTS: LPS stimulation increased significantly the mRNA and protein expression of TPO and ERK in BV2 cells, especially at the concentration of 1.0 µg/mL for 12 hrs stimulation. There was a significant positive correlation between the mRNA and protein expression of TPO and ERK. CONCLUSIONS: Signal transduction pathway of ERK1/2 participates in the activation of TPO in inflammatory injury of BV2 cells.


Assuntos
Inflamação/etiologia , Microglia/patologia , Transdução de Sinais/fisiologia , Trombopoetina/fisiologia , Animais , Ensaio de Imunoadsorção Enzimática , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Camundongos , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Trombopoetina/análise , Trombopoetina/genética
10.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 25(7): 633-6, 2005 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-16089143

RESUMO

OBJECTIVE: To explore the neuro-protective effect and mechanism of qingkailing injection (QKL) against cerebral injury caused by E. coli-meningitis (CM). METHODS: The CM model rabbits were treated by ampicillin with QKL as adjuvant. The leukocyte count and protein content in cerebral spinal fluid (CSF), the contents of water, sodium, potassium and calcium in cerebral tissues were measured before, 16 h and 26 h after Bacillus coli injection respectively. The expression of matrix metalloproteinase-9 (MMP-9) was determined at the same time. RESULTS: Adjunctive treatment with QKL can not only inhibit the increase of leukocyte cells, protein content in CSF, and water, sodium, calcium content in cerebral tissues, but also the decrease of potassium content revealed during simple antibiotic treatment. It also can decrease the expression of MMP-9 in cerebral tissues of rabbits with CM. CONCLUSION: As an adjunctive treatment, QKL can prevent transient inflammatory reaction and aggravation of brain injury in CM induced by simple antibiotic treatment, its mechanisms might relate with calcium antagonism and attenuation of MMP-9 expression in brain tissues.


Assuntos
Ampicilina/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico , Meningite devida a Escherichia coli/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Fitoterapia , Animais , Antibacterianos/uso terapêutico , Encéfalo/metabolismo , Quimioterapia Combinada , Feminino , Injeções , Masculino , Metaloproteinase 9 da Matriz/biossíntese , Coelhos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA