Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
1.
Brain Res ; 1835: 148914, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38580047

RESUMO

Closed-loop deep brain stimulation (DBS) system offers a promising approach for treatment-resistant depression, but identifying universally accepted electrophysiological biomarkers for closed-loop DBS systems targeting depression is challenging. There is growing evidence suggesting a strong association between the lateral habenula (LHb) and depression. Here, we took LHb as a key target, utilizing multi-site local field potentials (LFPs) to study the acute and chronic changes in electrophysiology, functional connectivity, and brain network characteristics during the formation of a chronic restraint stress (CRS) model. Furthermore, our model combining the electrophysiological changes of LHb and interactions between LHb and other potential targets of depression can effectively distinguish depressive states, offering a new way for developing effective closed-loop DBS strategies.

2.
Microsc Res Tech ; 86(11): 1529-1541, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37382312

RESUMO

During orthodontic tooth movement (OTM), osteocytes, the most mechanosensitive cells in alveolar bone, suffer the heavy orthodontic force and initiate alveolar bone resorption on the compression side. However, the inherent mechanisms of compressive force-induced osteocyte death are not fully understood. In this study, we established an OTM model on Sprague-Dawley rats by inserting coil springs to investigate osteocyte damage on the compression side of alveolar bone. We then applied compressive force on the MLO-Y4 osteocyte-like cell line in vitro to explore whether the reactive oxygen species (ROS)-mediated endoplasmic reticulum stress (ERS) pathway is involved in compressive force-induced osteocyte death. We found that the orthodontic force caused apparent alveolar bone loss, osteocyte death, and elevated serum sclerostin and receptor activator of NF-κB ligand (RANKL) levels in rats. In vitro, compressive force inhibited cell viability but increased the LDH leakage and loss of mitochondrial membrane potential in MLO-Y4 cells. Simultaneously, it activated protein kinase RNA-like endoplasmic reticulum kinase (PERK), eukaryotic translation initiation factor 2 (eIF2α), and their downstream pro-apoptotic ERS signaling proteins and caused significant osteocyte apoptosis, which can be blocked by ERS inhibitor salubrinal. Moreover, the compressive force elevated intracellular ROS levels, while the ROS scavenger N-acetyl-L-cysteine (NAC) alleviated ERS and apoptosis in loaded osteocytes. These results suggest that the orthodontic compressive force induced osteocyte apoptosis via the ROS-mediated ERS pathway. This study first proposes the ERS pathway as a new potential pathway for regulating the rate of OTM based on osteocyte death. RESEARCH HIGHLIGHTS: The orthodontic force increases osteocyte death in rat alveolar bone. The compressive force causes osteocyte apoptosis by the endoplasmic reticulum stress (ERS) pathway in vitro. The ROS scavenger NAC blocked compressive force-induced ERS and osteocyte apoptosis.


Assuntos
Perda do Osso Alveolar , Osteócitos , Ratos , Animais , Espécies Reativas de Oxigênio/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais , Perda do Osso Alveolar/metabolismo , Estresse do Retículo Endoplasmático , Apoptose
3.
Mult Scler Relat Disord ; 70: 104496, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36623395

RESUMO

OBJECTIVE: The differences in magnetic resonance imaging (MRI) between children with classic acute disseminated encephalomyelitis (ADEM) and myelinal oligodendrocyte glycoprotein antibody associated disease (MOGAD) with ADEM-like presentation are controversial. The purpose of this study was to investigate whether the radiological characteristics of the MRI-FLAIR sequence can predict MOGAD in children with ADEM-like presentation and to further explore its imaging differences. METHODS: We extracted 1041 radiomics features from MRI-FLAIR lesions. Then we used the redundancy analysis (Spearman correlation coefficient), significance test (student test or Mann-Whitney U test), least absolute contraction and selection operator (LASSO) to select potential predictors from the feature groups. The selected potential predictors and MOG antibody test results were used to fit the machine learning model for classification. Combined with feature selection and machine learning classifiers, the optimal model for each subgroup was derived. The resulting models have been evaluated using the receiver operator characteristic curve (ROC) at the lesion level and the model performance was evaluated at the case level using decision curve analysis. RESULTS: We retrospectively reviewed and re-diagnosed 70 ADEM-like presentation cases in our center from April 2015 to January 2020. Including 49 cases with classic ADEM and 21 cases with MOGAD. 30(43%) were female, with a median age of 5.3 years. On the four subgroups by age and gender, the area under the curve (AUC) of the optimal models were 89%, 90%, 98%, and 99%, and the MOGAD detection rates (Specificity) were 83%, 83%, 92%, and 75%, respectively. CONCLUSIONS: The machine learning model trained on radiomics features of MR-FLAIR images can effectively predict patients' MOGAD. This study provides a fast, objective, and quantifiable method for MOGAD diagnosis.


Assuntos
Encefalomielite Aguda Disseminada , Feminino , Masculino , Humanos , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos , Autoanticorpos
4.
J Zhejiang Univ Sci B ; 23(8): 625-641, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35953757

RESUMO

Stroke has a high incidence and disability rate, and rehabilitation is an effective means to reduce the disability rate of patients. To systematize rehabilitation assessment, which is the foundation for rehabilitation therapy, we summarize the assessment methods commonly used in research and clinical applications, including the various types of stroke rehabilitation scales and their applicability, and related biomedical detection technologies, including surface electromyography (sEMG), motion analysis systems, transcranial magnetic stimulation (TMS), magnetic resonance imaging (MRI), and combinations of different techniques. We also introduce some assessment techniques that are still in the experimental phase, such as the prospective application of artificial intelligence (AI) with optical correlation tomography (OCT) in stroke rehabilitation. This review provides a useful bibliography for the assessment of not only the severity of stroke injury, but also the therapeutic effects of stroke rehabilitation, and establishes a solid base for the future development of stroke rehabilitation skills.


Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Inteligência Artificial , Humanos , Imageamento por Ressonância Magnética , Reabilitação do Acidente Vascular Cerebral/métodos , Estimulação Magnética Transcraniana/métodos
5.
CNS Neurosci Ther ; 28(10): 1492-1508, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35896511

RESUMO

OBJECTIVES: To systematically review studies using remote ischemia postconditioning (RIPostC) for ischemic stroke in experimental models and obtain factors that significantly influence treatment outcomes. MATERIALS AND METHODS: Peer-reviewed studies were identified and selected based on the eligibility criteria, followed by extraction of data on potentially influential factors related to model preparation, postconditioning, and measure time based on outcome measures including infarct size, neurological scales, and cell tests with autophagy, apoptosis, normal-neuron, and damaged-neuron counting. Then, all data were preprocessed, grouped, and meta-analyzed with the indicator of the standardized mean difference. RESULTS: Fifty-seven studies with 224 experiments (91 for infarct size, 92 for neurological scales, and 41 for cell-level tests) were included. There was little statistical difference between different model preparations, treated body parts, number of treatments, and sides. And treatment effect was generally a positive correlation with the duration of conditioning time to stroke onset with exceptions at some time points. Based on infarct size, the number of cycles per treatment, duration of occlusion, and release per cycle showed significant differences. Combined with the effect sizes by other measures, the occlusion/release duration of 8-10 min per cycle is better than 5 min, and three cycles per treatment were most frequently used with good effects. Effect also varied when measuring at different times, showing statistical differences in infarct size and most neurological scales. RIPostC is confirmed as an effective therapeutic intervention for ischemic stroke, while the RIPostC-mediated autophagy level being activated or inhibited remained conflicting. CONCLUSIONS: Conditioning time, number of cycles per treatment, duration of occlusion, and release per cycle were found to influence the treatment effects of RIPostC significantly. More studies on the relevant influential factors and autophagy mechanisms are warranted.


Assuntos
Pós-Condicionamento Isquêmico , AVC Isquêmico , Acidente Vascular Cerebral , Autofagia/fisiologia , Humanos , Infarto , Acidente Vascular Cerebral/terapia
6.
Sci Rep ; 12(1): 6349, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35428800

RESUMO

The development of 3D printing has recently attracted significant attention on constructing complex three-dimensional physiological microenvironments. However, it is very challenging to provide a bio-ink with cell-harmless and high mold accuracy during extrusion in 3D printing. To overcome this issue, a technique improving the shear-thinning performance of semi-IPN bio-ink, which is universally applicable to all alginate/gelatin-based materials, was developed. Semi-IPN bio-ink prepared by cyclic heating-cooling treatment in this study can reduce the cell damage without sacrificing the accuracy of the scaffolds for its excellent shear-thinning performance. A more than 15% increase in post-printing Cell viability verified the feasibility of the strategy. Moreover, the bio-ink with low molecular weight and wide molecular weight distribution also promoted a uniform cell distribution and cell proliferation in clusters. Overall, this strategy revealed the effects of molecular parameters of semi-IPN bio-inks on printing performance, and the cell activity was studied and it could be widely applicable to construct the simulated extracellular matrix with various bio-inks.


Assuntos
Bioimpressão , Bioimpressão/métodos , Matriz Extracelular , Hidrogéis/farmacologia , Tinta , Peso Molecular , Impressão Tridimensional , Engenharia Tecidual/métodos , Alicerces Teciduais
7.
Biomed Opt Express ; 10(12): 6258-6271, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31853398

RESUMO

The optical attenuation coefficient (OAC) estimated using optical coherence tomography (OAC-OCT) offers a label-free 3D mapping of tissue infarction, but the physiological origin of the OAC contrast remains unclear. For effectively suppressing OAC fluctuations, we propose a hybrid (wavelength/angle) division multiplexing (HDM) method, which improved the OAC contrast by 70.7% in tissue phantoms. To test the feasibility of OAC-based infarction detection, triphenyltetrazolium chloride (TTC) staining was performed on fresh ex vivo brain slices, and the TTC-defined infarction was used as the ground truth. Sharp OAC contrast was observed between the TTC-defined infarction (1.09 mm-1) and normal tissue (0.79 mm-1). The OAC infarction spatially matched well with the TTC-defined infarction. To further explore the physiological origin of OAC contrast in ischemic stroke at the cellular level, the dynamic changes in OAC were measured in the rat cortex in vivo over 3 weeks after photothrombosis (PT) occlusion and found significantly correlated with the changes in astrocytes and neurons acquired with ex vivo hematoxylin and eosin (HE), glial fibrillary acidic protein (GFAP), and NeuN staining. These results suggest that OAC imaging enables non-invasive infarction detection and its contrast might originate from the changes in astrocytes and neurons in the chronic PT stroke model. The cellular responses revealed by in vivo OAC imaging would be essential for evaluating treatments and even developing novel therapies.

8.
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
9.
J Cereb Blood Flow Metab ; 39(7): 1381-1393, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-29521548

RESUMO

A thorough understanding of the spatiotemporal dynamics of blood supply and tissue viability is of great importance in stroke researches. In the current study, vascular and cellular responses to focal ischemia were monitored with optical coherence tomography on chronic rat photothrombotic stroke model. The 3D mapping of blood perfusion and cellular scattering were achieved by analyzing the temporal dynamics and depth attenuation of intrinsic backscattered light respectively. Optical coherence tomography revealed that vessels of different types presented various spatial and temporal dynamics during the photothrombotic occlusion and the later recovery period. The large distal middle cerebral arteries presented a spontaneous recanalization and the small pial microvessels presented a reperfusion along with newly appeared vessels from the peripheral into the core area. The cortical capillary perfusion presented a weak recovery. Compared to the male group, the female rats showed a faster vascular recovery after photothrombotic. Moreover, the dynamic changes of the cellular scattering signal showed a high spatial and temporal correlation with the cortical capillary perfusion. Combined with well-designed photothrombotic stroke model and chronic optical window, optical coherence tomography imaging offers a unique approach to improve the understanding of stroke procedure and evaluate the treatment outcomes.


Assuntos
Córtex Cerebral/irrigação sanguínea , Circulação Cerebrovascular/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Tomografia de Coerência Óptica , Animais , Capilares/patologia , Capilares/fisiopatologia , Modelos Animais de Doenças , Feminino , Lasers , Masculino , Artéria Cerebral Média/patologia , Artéria Cerebral Média/fisiopatologia , Ratos , Ratos Sprague-Dawley , Reperfusão , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/cirurgia , Trombose
10.
Entropy (Basel) ; 21(7)2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-33267412

RESUMO

Complex nerve remodeling occurs in the injured brain area during functional rehabilitation after a brain injury; however, its mechanism has not been thoroughly elucidated. Neural remodeling can lead to changes in the electrophysiological activity, which can be detected in an electroencephalogram (EEG). In this paper, we used EEG band energy, approximate entropy (ApEn), sample entropy (SampEn), and Lempel-Ziv complexity (LZC) features to characterize the intrinsic rehabilitation dynamics of the injured brain area, thus providing a means of detecting and exploring the mechanism of neurological remodeling during the recovery process after brain injury. The rats in the injury group (n = 12) and sham group (n = 12) were used to record the bilateral symmetrical EEG on days 1, 4, and 7 after a unilateral brain injury in awake model rats. The open field test (OFT) experiments were performed in the following three groups: an injury group, a sham group, and a control group (n = 10). An analysis of the EEG data using the energy, ApEn, SampEn, and LZC features demonstrated that the increase in SampEn was associated with the functional recovery. After the brain injury, the energy values of the delta1 bands on day 4; the delta2 bands on days 4 and 7; the theta, alpha, and beta bands and the values of ApEn, SampEn, and LZC of the cortical EEG signal on days 1, 4 and 7 were significantly lower in the injured brain area than in the non-injured area. During the process of recovery for the injured brain area, the values of the beta bands, ApEn, and SampEn of the injury group increased significantly, and gradually became equal to the value of the sham group. The improvement in the motor function of the model rats significantly correlated with the increase in SampEn. This study provides a method based on EEG nonlinear features for measuring neural remodeling in injured brain areas during brain function recovery. The results may aid in the study of neural remodeling mechanisms.

11.
Life Sci ; 195: 53-60, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-29307521

RESUMO

AIMS: NK cells play important roles in inhibiting HBV replication and preventing HBV infection. However, NK-cell dysfunction has not been fully studied in asymptomatic chronic HBV carriers (ASC). This study aims to assess decreased expression of CD122 associated with impaired NK cells and the restoration of NK cells with IL-2 and IL-15 stimulation. MAIN METHODS: The experiments were performed by flow cytometer, cytotoxicity assay, ELISA and western blotting. KEY FINDINGS: The reduced CD122 on CD56+ NK cells and CD56dim NK cells is associated with high levels of HBV DNA, HBsAg or HBeAg in ASCs, in which CD56dim NK-cell impairment is observed. Moreover, decreased IFN-γ and degranulation and low cytotoxicity by CD56dim NK cells after CD122 blockade were revealed. IL-2 and/or IL-15 can restore impaired CD56dim NK cells, together with increased p-STAT5, which can be reversed by CD122 blockade. Additionally, IL-2 or IL-15 can enhance IFN-α2-activated CD56dim NK-cell immune responses via up-regulating interferon alpha and beta receptor subunit 2 (IFNAR2). SIGNIFICANCE: Down-regulated CD122 on CD56dim NK cell in ASCs with massive viral antigens and high viremia is associated with its impairment, which can be restored by IL-2 and/or IL-15, or combined with IFN-α2.


Assuntos
Antígeno CD56/biossíntese , DNA Viral/biossíntese , Antígenos de Superfície da Hepatite B/sangue , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B/metabolismo , Hepatite B/metabolismo , Subunidade beta de Receptor de Interleucina-2/biossíntese , Células Matadoras Naturais/metabolismo , Adulto , Antígeno CD56/genética , Portador Sadio , DNA Viral/genética , Feminino , Vírus da Hepatite B/genética , Humanos , Interferon gama/biossíntese , Interleucina-15/farmacologia , Interleucina-2/farmacologia , Subunidade beta de Receptor de Interleucina-2/genética , Masculino , Receptor de Interferon alfa e beta/biossíntese , Receptor de Interferon alfa e beta/genética , Fator de Transcrição STAT5/biossíntese , Fator de Transcrição STAT5/genética , Viremia/sangue , Viremia/virologia
12.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 34(4): 299-303 317, 2018 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-30788935

RESUMO

OBJECTIVE: To explore the effect of ambient particle matter 2.5 (PM2.5) collected in the urban center of Hangzhou on the lung injury of rats and on the activating of endoplasmic reticulum pathway. METHODS: PM2.5 samples were collected on quartz fiber filters using a PM2.5 high-volume air sampler in the urban area of Hangzhou. The collected PM2.5 particles were extracted in ultrapure water and concentrated by vacuum freeze-drying. Twenty-four male Sprague-Dawly (SD) rats were randomly divided into 3 groups:saline control group, low dose PM2.5 exposure group (5 mg/kg BW) and high dose PM2.5 exposure groups (25 mg/kg BW). Each group received intratracheal instillation of PM2.5, once a week for 4 weeks. Twenty-four hours after the last exposure, the rats were narcotized and sacrificed, left lung was isolated and fixed with 4% paraformaldehyde for histopathological detection. The bronchoalveolar lavage fluid (BALF) was collected from the right lung. The total antioxidant capacity (T-AOC) level, the activities of superoxide dismutase (SOD) and lactic dehydrogenase (LDH) in BALF were detected by chemical colorimetry. The level of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß) and interleukin-6 (IL-6) cytokines in BALF was measured by enzyme linked immunosorbent assay (ELISA). And the protein expressions of glucose-regulated protein 78 (GRP78), phosphorylated protein kinase receptor-like endoplasmic reticulum kinase (p-PERK), phosphorylated eukaryotic translation initiation factor (p-eIF2α), transcription factors C/EBP homologue protein (CHOP), inositol-requiring enzyme 1α (IRE1α) and X-box binding protein 1 (XBP1) in lung tissue were determined by Western blotting. RESULTS: Compared with control group, rats in both low dose (5 mg/kg) and high dose (25 mg/kg) PM2.5-treated groups showed obviously dose-dependent pulmonary toxicity including thickening of alveolar walls, narrowing of alveolar space, interstitial hyperplasia and inflammatory cell infiltration. Compared with control group, T-AOC level and the SOD activity in BALF in both PM2.5-treated groups were decreased dose-dependently (P<0.05), whereas the LDH activity in BALF were increased in a dose-dependent manner (P<0.05). Exposure to PM2.5 resulted in a increasing of the release of proinflammatory cytokines including TNF-α, IL-1ß and IL-6 in rat lung in a dose-dependent manner (P<0.05). The levels of GRP78, p-PERK, p-eIF2α, CHOP, IRE1α and spliced XBP1 (XBP1-S) were significantly up-regulated, whereas the level of unspliced XBP1 (XBP1-U) was down-regulated in the rat lung tissue of high-dose PM2.5 treated group. CONCLUSIONS: The PM2.5 in the urban area of Hangzhou can significantly cause lung inflammatory injury in rats. Both oxidative stress and activation of ER stress pathways may be related to such PM2.5 inhalation-induced lung inflammatory injury.


Assuntos
Lesão Pulmonar , Material Particulado , Animais , Líquido da Lavagem Broncoalveolar , Interleucina-6 , Pulmão , Masculino , Ratos
13.
Int J Nanomedicine ; 11: 529-42, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26893560

RESUMO

Cadmium telluride quantum dots (CdTe QDs) have been proposed to induce oxidative stress, which plays a crucial role in CdTe QDs-mediated mitochondrial-dependent apoptosis in human umbilical vein endothelial cells (HUVECs). However, the direct interactions of CdTe QDs with HUVECs and their potential impairment of other organelles like endoplasmic reticulum (ER) in HUVECs are poorly understood. In this study, we reported that the negatively charged CdTe QDs (-21.63±0.91 mV), with good dispersity and fluorescence stability, were rapidly internalized via endocytosis by HUVECs, as the notable internalization could be inhibited up to 95.52% by energy depletion (NaN3/deoxyglucose or low temperature). The endocytosis inhibitors (methyl-ß-cyclodextrin, genistein, sucrose, chlorpromazine, and colchicine) dramatically decreased the uptake of CdTe QDs by HUVECs, suggesting that both caveolae/raft- and clathrin-mediated endocytosis were involved in the endothelial uptake of CdTe QDs. Using immunocytochemistry, a striking overlap of the internalized CdTe QDs and ER marker was observed, which indicates that QDs may be transported to ER. The CdTe QDs also caused remarkable ER stress responses in HUVECs, confirmed by significant dilatation of ER cisternae, upregulation of ER stress markers GRP78/GRP94, and activation of protein kinase RNA-like ER kinase-eIF2α-activating transcription factor 4 pathway (including phosphorylation of both protein kinase RNA-like ER kinase and eIF2α and elevated level of activating transcription factor 4). CdTe QDs further promoted an increased C/EBP homologous protein expression, phosphorylation of c-JUN NH2-terminal kinase, and cleavage of ER-resident caspase-4, while the specific inhibitor (SP600125, Z-LEVD-fmk, or salubrinal) significantly attenuated QDs-triggered apoptosis, indicating that all three ER stress-mediated apoptosis pathways were activated and the direct participation of ER in the CdTe QDs-caused apoptotic cell death in HUVECs. Our findings provide important new insights into QDs toxicity and reveal potential cardiovascular risks for the future applications of QDs.


Assuntos
Compostos de Cádmio/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Pontos Quânticos , Telúrio/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Compostos de Cádmio/química , Colchicina/farmacologia , Endocitose/efeitos dos fármacos , Chaperona BiP do Retículo Endoplasmático , Fluorescência , Genisteína/farmacologia , Proteínas de Choque Térmico/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Pontos Quânticos/química , Telúrio/química , Tiomalatos/química , beta-Ciclodextrinas/farmacologia , eIF-2 Quinase/metabolismo
14.
Nitric Oxide ; 38: 17-25, 2014 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-24534135

RESUMO

Little is known about role of Nitric Oxide (NO) of ischemic postconditioning in global cerebral ischemia and reperfusion (I/R) injury. In this study, we detected the dynamic change of NO during the ischemic postconditioning against global cerebral I/R in vivo, and compared the effects of six postconditioning conditions with different numbers of cycles and periods for reperfusion/occlusion. The animals underwent postconditioning consisting of 3 or 10 cycles of 15-s reperfusion, followed by 15-s occlusion (post-3-15/15, post-10-15/15), or 3 or 10 cycles of 30-s reperfusion/30-s occlusion (post-3-30/30, post-10-30/30), or 3 or 10 cycles of 60-s reperfusion/15-s occlusion (post-3-60/15, post-10-60/15). The results showed that four groups increased NO concentration, while all groups improved CBF significantly. Different postconditioning groups had different effects on NO and CBF. Post-3-30/30 had the strongest effect on both. Also it reduced infarct size from 33.0% to 24.29%, and downregulated the cell death ratio from 6.71% to 1.04%, showing the strongest protective effect among tested conditions. And we found that post-3-30/30 was an optional method in ischemic postconditioning, which obviously induced a large amount of NO synthesis with a slow speed, increased CBF and reduced the brain injuries. Therefore we concluded that NO is a reliable candidate in mediating ischemic postconditioning neuroprotection.


Assuntos
Isquemia Encefálica/metabolismo , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Pós-Condicionamento Isquêmico , Óxido Nítrico/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Animais , Masculino , Fármacos Neuroprotetores/metabolismo , Óxido Nítrico/análise , Ratos , Ratos Sprague-Dawley
15.
Clin Res Hepatol Gastroenterol ; 36(6): 592-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23069315

RESUMO

The aim of this study was to compare the efficacy of lamivudine or adefovir alone for 96 weeks versus initial treatment with the combination of lamivudine and adefovir for 12 to 24 weeks followed by adefovir alone. One hundred and fifty patients with HBeAg-positive chronic hepatitis B were randomized equally to lamivudine and adefovir diprivoxil combination therapy (LA), lamivudine alone (L), or adefovir dipivoxil alone (A) in a multicenter randomized clinical trial. In the LA group, the earliest time for lamivudine discontinuation was 12 weeks and adefovir monotherapy was continued until 96 weeks. Groups L and A received monotherapies for 96 weeks. At 12 weeks, the decrease in HBV DNA, percentage of patients with negative HBV DNA, and ALT normalization rate for the LA group were comparable to those of group L, but superior to those of group A. At 24 weeks, the rates of negative HBV DNA and HBeAg seroconversion of group LA were significantly higher than the monotherapy groups. This superiority was subsequently preserved during the maintenance phase with adefovir monotherapy. Starting at 48 weeks, the mean HBV DNA level of group L increased over the 24-week level. In contrast, the A group's rates of virological response, biochemical response, and HBeAg seroconversion continued to improve. At week 96, the percentage of patients with undetectable DNA and HBe seroconversion of LA group (100%, 51%) was higher than that of L (66%, 21%) and A group (49%, 33%), while no significant difference was observed between the L and A groups. During the course of therapy, no lamivudine- or adefovir-resistance mutations were discovered in the LA group. Rates of adverse reactions were comparable between the three groups. Combination therapy with lamivudine and adefovir for 12 to 24 weeks followed by adefovir monotherapy significantly improved antiviral efficacy and reduced drug resistance without compromising safety and tolerability compared to either drug alone in HBeAg-positive chronic hepatitis B.


Assuntos
Adenina/análogos & derivados , Antivirais/administração & dosagem , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/sangue , Hepatite B Crônica/tratamento farmacológico , Lamivudina/administração & dosagem , Organofosfonatos/administração & dosagem , Inibidores da Transcriptase Reversa/administração & dosagem , Adenina/administração & dosagem , Adulto , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-305084

RESUMO

<p><b>OBJECTIVE</b>To evaluate the effect of combination therapy with peginterferon alfa-2a (Pegasys) +/- nucleos(t)ide analogues (NUC) and bicyclol in chronic hepatitis B with high ALT levels at baseline and during early treatment.</p><p><b>METHODS</b>CHB patients were treated with PEG-IFNalpha-2a for a minimum of 48 weeks. All patients were followed up for 26 weeks post-treatment. Patients with HBV DNA > or = 1 x 10(8) copies/ml were combined with NUC (adefovir or entecavir) treatment. Patients with ALT > 500 U/L at baseline or ALT > 300 U/L after first injection of PEG-IFNalpha-2a received bicyclol treatment for 1-2 months (treatment group). Patients with 2 x ULN < ALT < 300 U/L and ALT < 300 U/L during treatment were enrolled into PEG-IFNalpha-2a +/- NUC antiviral monotherapy (control group). Responses defined as HBV DNA < 1 x 10(3) copies/ml, normal serum ALT, and HBeAg/HBsAg loss and seroconversion were analyzed at 26 weeks post-treatment.</p><p><b>RESULTS</b>A total of 54 patients (44 HBeAg positive, 10 HBeAg negative) were divided into two groups according to combination of bicyclol: treatment group (n = 20)--those who received combinition therapy with PEG-IFNalpha-2a +/- NUC and bicyclol, and control group (n = 34)--those who were treated with PEG-IFNalpha-2a +/- NUC antiviral monotherapy. During the first month of treatment, ALT levels declined gradually in treatment group. At 26 weeks post-treatment, the rates of ALT normalization and HBV DNA below the limit of 1 x 10(3) copies/ml were similar in both groups. Six patients in treatment group achieved HBsAg seroconversion at 26 weeks post-treatment, whereas so did 4 patients of control group (30% vs. 11.8%, P = 0.044).</p><p><b>CONCLUSION</b>Bicyclol could significantly relief elevation of ALT induced by the IFN treatment.</p>


Assuntos
Humanos , Alanina Transaminase , Sangue , Compostos de Bifenilo , DNA Viral , Quimioterapia Combinada , Antígenos de Superfície da Hepatite B , Sangue , Antígenos E da Hepatite B , Sangue , Hepatite B Crônica , Sangue , Tratamento Farmacológico , Interferon-alfa , Polietilenoglicóis , Proteínas Recombinantes
17.
Methods Mol Biol ; 704: 73-80, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21161630

RESUMO

Nitric oxide has been implicated as a mediator of synaptic transmission and a pathological factor in stroke/reperfusion. The purpose of this study was to detect the change of nitric oxide concentration in rat hippocampus during global cerebral ischemia and reperfusion in vivo and to reveal effects of different nitric oxide synthases. In the present study, the real-time record of nitric oxide levels in rat hippocampus was obtained by using a nitric oxide sensor during global cerebral ischemia and the initial stage of reperfusion. We also observed the effects of two inhibitors of nitric oxide synthases on nitric oxide concentration. The two inhibitors were administrated intravenously at the onset of reperfusion and 1 h later. The change of the nitric oxide concentration in the initial stage of reperfusion was 0.768 ± 0.029 µM. 7-Nitroindazole (7-NI7-NI , inhibitor of nNOS) had a strong inhibitive effect on nitric oxide synthesis at both time points, while 1400 W1400 W dihydrochloride (1400 W, inhibitor of iNOSiNOS ) had no significant effect on nitric oxide synthesis. The results showed that during the initial stage of reperfusion, nitric oxide biosynthesis was mainly an nNOS-dependent process.


Assuntos
Isquemia Encefálica/metabolismo , Hipocampo/metabolismo , Óxido Nítrico/análise , Traumatismo por Reperfusão/metabolismo , Amidinas/farmacologia , Animais , Benzilaminas/farmacologia , Eletrodos , Indazóis/farmacologia , Óxido Nítrico/biossíntese , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Ratos , Análise de Regressão , Relação Estrutura-Atividade , Fatores de Tempo
18.
Brain Inj ; 23(5): 450-8, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19408167

RESUMO

PURPOSE: Nitric oxide (NO) has been implicated as a mediator of synaptic transmission and a pathological factor in stroke/reperfusion. The purpose of this study was to detect the change of NO concentration in rat hippocampus during global cerebral ischemia and reperfusion in vivo and to reveal effects of different NO synthases (NOS). METHOD: In the present study, the real-time record of NO levels in rat hippocampus was obtained by using a NO sensor during the global cerebral ischemia and the initial stage of reperfusion. The effects of two inhibitors of NOS on NO concentration were also observed. The two inhibitors were respectively administrated intravenously at the onset of reperfusion and 1 hour later. RESULTS: The change of the NO concentration in the initial stage of reperfusion was 0.768 +/- 0.029 microM. 7-nitroindazole (7-NI, inhibitor of nNOS) had a strong inhibitive effect on NO synthesis at both time points, while 1400W dihydrochloride (1400W, inhibitor of iNOS) had no significant effect on the NO synthesis. CONCLUSIONS: The in vivo detection revealed the real dynamic change of NO concentration, which is much more reliable than the in vitro method. The results showed that, during the initial stage of reperfusion, NO biosynthesis was mainly in an nNOS-dependent manner. Thus, the toxicity of NO in this process had a close relationship with the activity of nNOS but not iNOS.


Assuntos
Hipocampo/metabolismo , Óxido Nítrico/metabolismo , Traumatismo por Reperfusão/metabolismo , Acidente Vascular Cerebral/metabolismo , Animais , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Iminas/farmacologia , Indazóis/farmacologia , Infusões Intravenosas , Masculino , Óxido Nítrico/análise , Óxido Nítrico Sintase/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley
19.
J Neurosci Res ; 86(10): 2281-91, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18381763

RESUMO

Increased hemichannel opening induced by oxygen glucose deprivation (OGD) was reported in the hippocampal pyramidal neuron. It was suggested that the pannexin1 hemichannel opening could mediate ionic flux dysregulation, anoxic depolarization, and energy-depleting efflux of glucose and ATP for ischemic neurons. However, the regulatory mechanisms of pannexin1 hemichannel opening have been poorly understood. Here we showed that excessive generation of nitric oxide (NO) during ischemia could induce the calcein leakage from neurons, which was markedly reduced by NO synthase inhibitor. The calcein leakage from neurons during OGD was also attenuated by the application of N-ethylmaleimide (NEM), an SH-alkylating agent, and dithiothreitol (DTT), a reducer of oxidized sulfhydryl groups. However, the soluble guanylyl cyclase (sGC) inhibitor had a minor effect on the calcein leakage during OGD. Furthermore, the elevated intracellular but not extracellular levels of glutathione could also inhibit the calcein leakage during OGD. Similar results were observed in metabolic inhibition (MI), which is another ischemic-like condition. Finally, immunocytochemical and immunoblotting analysis revealed that, after 1 hr of OGD stimulation, the distribution and expression of pannexin1 showed no significant difference compared with control. However, the pannexin1 mRNA expression was elevated after 1 hr of OGD and a sustained increase was maintained during reperfusion. These results implied that the reactive oxygen species (ROS), especially NO, might be involved in the enhanced pannexin1 hemichannel opening and that the S-nitrosylation but not the NO/cGMP pathway played a more important role in this event.


Assuntos
Hipóxia Celular/fisiologia , Permeabilidade da Membrana Celular/fisiologia , Hipocampo/metabolismo , Óxido Nítrico/metabolismo , Animais , Western Blotting , Permeabilidade da Membrana Celular/efeitos dos fármacos , Conexinas/metabolismo , GMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Fluoresceínas/metabolismo , Corantes Fluorescentes/metabolismo , Glucose/deficiência , Hipocampo/efeitos dos fármacos , Imuno-Histoquímica , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...