Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
Mol Psychiatry ; 27(4): 2146-2157, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35105968

RESUMO

It is essential to identify the neuronal mechanisms of Alzheimer's Disease (AD)-associated neuropsychiatric symptoms, e.g., apathy, before improving the life quality of AD patients. Here, we focused on the nucleus accumbens (NAc), a critical brain region processing motivation, also known to display AD-associated pathological changes in human cases. We found that the synaptic calcium permeable (CP)-AMPA receptors (AMPARs), which are normally absent in the NAc, can be revealed by acute exposure to Aß oligomers (AßOs), and play a critical role in the emergence of synaptic loss and motivation deficits. Blockade of NAc CP-AMPARs can effectively prevent AßO-induced downsizing and pruning of spines and silencing of excitatory synaptic transmission. We conclude that AßO-triggered synaptic insertion of CP-AMPARs is a key mechanism mediating synaptic degeneration in AD, and preserving synaptic integrity may prevent or delay the onset of AD-associated psychiatric symptoms.


Assuntos
Doença de Alzheimer , Receptores de AMPA , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Cálcio/metabolismo , Humanos , Motivação , Núcleo Accumbens/metabolismo , Receptores de AMPA/metabolismo , Receptores de Detecção de Cálcio , Sinapses/metabolismo , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico
2.
J Int Med Res ; 52(5): 3000605241238983, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38729774

RESUMO

OBJECTIVE: This study was performed to evaluate the mid-term clinical efficacy of the Femoral Neck System (FNS) (DePuy Synthes, Zuchwil, Switzerland) in treating young patients with unstable Pauwels type III femoral neck fractures. METHODS: We performed a retrospective observational analysis of 21 young adults treated with the FNS. Clinical outcomes were assessed based on fracture reduction quality, Harris hip scores, and postoperative complication rates. RESULTS: The study comprised 21 patients with a mean age of 35 years (range, 20-50 years) who were followed for a mean duration of 22.8 months (range, 16-30 months). Closed reduction was unfeasible in three (14.3%) patients, each of whom required open reduction. Notable postoperative complications were avascular necrosis in two (9.5%) patients, nonunion in one (4.7%), and implant failure in one (4.7%). Each of these complications led to the requirement for total hip arthroplasty. CONCLUSION: The favorable mid-term clinical outcomes of this study indicate that the FNS is a potentially effective treatment modality for young individuals with unstable Pauwels type III femoral neck fractures.


Assuntos
Fraturas do Colo Femoral , Fixação Interna de Fraturas , Humanos , Fraturas do Colo Femoral/cirurgia , Masculino , Feminino , Adulto , Estudos Retrospectivos , Adulto Jovem , Pessoa de Meia-Idade , Resultado do Tratamento , Fixação Interna de Fraturas/métodos , Complicações Pós-Operatórias/etiologia , Colo do Fêmur/cirurgia , Necrose da Cabeça do Fêmur/cirurgia , Necrose da Cabeça do Fêmur/etiologia
3.
bioRxiv ; 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38826399

RESUMO

Recent findings in our lab demonstrated that the risk of cocaine relapse is closely linked to the hyperexcitability of cortical pyramidal neurons in the secondary motor cortex (M2), noticeable 45 days after cocaine intravenous self-administration (IVSA). The present study was designed to explore the underlying mechanisms of neuronal alterations in M2. Our hypothesis was that M2 neurons were affected directly by cocaine taking behaviors. This hypothesis was tested by monitoring individual neuronal activity in M2 using MiniScopes for in vivo Ca 2+ imaging in C57BL/6J mice when they had access to cocaine IVSA as a reinforcement (RNF) contingent to active lever press (ALP) but not to inactive lever press (ILP). With support of our established pipeline to processing Ca 2+ imaging data, the current study was designed to monitor M2 neuronal ensembles at the single-neuron level in real time with high temporal resolution and high throughput in each IVSA session and longitudinally among multiple IVSA sessions. Specifically, five consecutive 1-hr daily IVSA sessions were used to model the initial cocaine taking behaviors. Besides detailed analyses of IVSA events (ALP, ILP, and RNF), the data from Ca 2+ imaging recordings in M2 were analyzed by (1) comparing neuronal activation within a daily IVSA session (i.e., the first vs. the last 15 min) and between different daily sessions (i.e., the first vs. the last IVSA day), (2) associating Ca 2+ transients with individual IVSA events, and (3) correlating Ca 2+ transients with the cumulative effects of IVSA events. Our data demonstrated that M2 neurons are exquisitely sensitive to and significantly affected by concurrent operant behaviors and the history of drug exposure, which in turn sculpt the upcoming operant behaviors and the response to drugs. As critical nodes of the reward loop, M2 neurons appear to be the governing center orchestrating the establishment of addiction-like behaviors.

4.
Cells ; 13(1)2023 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-38201293

RESUMO

High levels of alcohol intake alter brain gene expression and can produce long-lasting effects. FK506-binding protein 51 (FKBP51) encoded by Fkbp5 is a physical and cellular stress response gene and has been associated with alcohol consumption and withdrawal severity. Fkbp5 has been previously linked to neurite outgrowth and hippocampal morphology, sex differences in stress response, and epigenetic modification. Presently, primary cultured Fkbp5 KO and WT mouse neurons were examined for neurite outgrowth and mitochondrial signal with and without alcohol. We found neurite specification differences between KO and WT; particularly, mesh-like morphology was observed after alcohol treatment and confirmed higher MitoTracker signal in cultured neurons of Fkbp5 KO compared to WT at both naive and alcohol-treated conditions. Brain regions that express FKBP51 protein were identified, and hippocampus was confirmed to possess a high level of expression. RNA-seq profiling was performed using the hippocampus of naïve or alcohol-injected (2 mg EtOH/Kg) male and female Fkbp5 KO and WT mice. Differentially expressed genes (DEGs) were identified between Fkbp5 KO and WT at baseline and following alcohol treatment, with female comparisons possessing a higher number of DEGs than male comparisons. Pathway analysis suggested that genes affecting calcium signaling, lipid metabolism, and axon guidance were differentially expressed at naïve condition between KO and WT. Alcohol treatment significantly affected pathways and enzymes involved in biosynthesis (Keto, serine, and glycine) and signaling (dopamine and insulin receptor), and neuroprotective role. Functions related to cell morphology, cell-to-cell signaling, lipid metabolism, injury response, and post-translational modification were significantly altered due to alcohol. In summary, Fkbp5 plays a critical role in the response to acute alcohol treatment by altering metabolism and signaling-related genes.


Assuntos
Transtornos Relacionados ao Uso de Álcool , Etanol , Feminino , Masculino , Animais , Camundongos , Etanol/farmacologia , Metabolismo dos Lipídeos , Injeções , Consumo de Bebidas Alcoólicas , Glicina
5.
Front Bioeng Biotechnol ; 10: 972933, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36051580

RESUMO

The past decade has become an important strategy in precision medicine for the targeted therapy of many diseases, expecially various types of cancer. As a promising targeted element, nucleic acid aptamers are single-stranded functional oligonucleotides which have specific abilities to bind with various target molecules ranging from small molecules to entire organisms. They are often named 'chemical antibody' and have aroused extensive interest in diverse clinical studies on account of their advantages, such as considerable biostability, versatile chemical modification, low immunogenicity and quick tissue penetration. Thus, aptamer-embedded drug delivery systems offer an unprecedented opportunity in bioanalysis and biomedicine. In this short review, we endeavor to discuss the recent advances in aptamer-based targeted drug delivery platforms for cancer therapy. Some perspectives on the advantages, challenges and opportunities are also presented.

6.
J Magn Reson Imaging ; 34(1): 136-49, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21618336

RESUMO

PURPOSE: To test the accuracy of the most widely used technique based on edge detection for thickness measurement of the hip joint cartilage in MR images, and to improve the measurement accuracy by developing a new measurement method based on a model of the MRI process. MATERIALS AND METHODS: MRI was performed in 3 normal cadaver hips, 25 hips of normal volunteers, and 25 hips of patients with osteoarthritis. In general, thickness was defined as the distance between the two sides of the hip cartilage along the normal directions of the cartilage surfaces. In this article this is referred to as the "edge detection method." A theoretical simulation analysis revealed that the edge detection method considerably underestimated the cartilage thickness of the hip joint. A new measurement method based on a model of the MR imaging process was accordingly proposed for correcting the measurement errors. RESULTS: In the experiment using the cadaver hips, anatomical measurement of cartilage thickness was used as reference standard. For measurements at 35 sites, the proposed model-based method gave results similar to those presented from anatomic section, while the edge detection method gave underestimation compared with the anatomic thickness. The underestimation biases for the edge detection method were consistent with the biases predicted by theoretical simulation. In the experiment using the hips of volunteers and patients, the edge detection result was an underestimation compared with the result generated by using the model-based method. CONCLUSION: The edge detection method underestimated the hip cartilage thickness in MR images. The proposed model-based method was more accurate than the edge detection method for thickness measurement of the hip cartilage.


Assuntos
Cartilagem Articular/patologia , Articulação do Quadril/patologia , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Algoritmos , Cadáver , Cartilagem/patologia , Estudos de Casos e Controles , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Modelos Teóricos , Osteoartrite/patologia , Reprodutibilidade dos Testes
7.
Neurochem Res ; 36(3): 383-91, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21152977

RESUMO

Drug addiction, as well as learning and memory, share common mechanisms in terms of neural circuits and intracellular signaling pathways. In the present study, the role of N-methyl-D-aspartate (NMDA) receptors, particularly those containing NR2B subunits, in morphine-induced conditioned place preference (CPP) and Morris water maze (MWM) learning and memory task was investigated. CPP was used as a paradigm for assessing the rewarding effect of morphine, and MWM was used to measure spatial learning and memory in male Sprague-Dawley rats. We found that ifenprodil, an antagonist highly selective for NR2B-containing NMDA receptors, dose-dependently blocked the development, maintenance and reinstatement of morphine-induced CPP, without evident impairment of the acquisition and retrieval of spatial memory in the MWM task. However, the consolidation of spatial memory was disrupted by a high dose (10 mg/kg) of ifenprodil. These results clearly demonstrate that NR2B-containing NMDA receptors are actively involved in addiction memory induced by morphine conditioning, but not in the acquisition and retrieval of spatial learning and memory. In conclusion, NR2B-containing NMDA receptors can be considered potential targets for the treatment of opiate addiction.


Assuntos
Condicionamento Psicológico/efeitos dos fármacos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Morfina/farmacologia , Piperidinas/farmacologia , Comportamento Espacial/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Masculino , Entorpecentes/farmacologia , Ratos , Ratos Sprague-Dawley
8.
Front Neural Circuits ; 15: 711564, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34483848

RESUMO

Excitotoxicity is one of the primary mechanisms of cell loss in a variety of diseases of the central and peripheral nervous systems. Other than the previously established signaling pathways of excitotoxicity, which depend on the excessive release of glutamate from axon terminals or over-activation of NMDA receptors (NMDARs), Ca2+ influx-triggered excitotoxicity through Ca2+-permeable (CP)-AMPA receptors (AMPARs) is detected in multiple disease models. In this review, both acute brain insults (e.g., brain trauma or spinal cord injury, ischemia) and chronic neurological disorders, including Epilepsy/Seizures, Huntington's disease (HD), Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), chronic pain, and glaucoma, are discussed regarding the CP-AMPAR-mediated excitotoxicity. Considering the low expression or absence of CP-AMPARs in most cells, specific manipulation of the CP-AMPARs might be a more plausible strategy to delay the onset and progression of pathological alterations with fewer side effects than blocking NMDARs.


Assuntos
Cálcio , Doenças do Sistema Nervoso , Receptores de AMPA , Cálcio/metabolismo , Ácido Glutâmico , Humanos , Doenças do Sistema Nervoso/metabolismo , Receptores de AMPA/metabolismo , Receptores de Detecção de Cálcio
9.
CNS Neurosci Ther ; 27(2): 196-205, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33118700

RESUMO

AIMS: Limited vs extended drug exposure has been proposed as one of the key factors in determining the risk of relapse, which is the primary characteristic of addiction behaviors. The current studies were designed to explore the related behavioral effects and neuronal alterations in the insular cortex (IC), an important brain region involved in addiction. METHODS: Experiments started with rats at the age of 35 days, a typical adolescent stage when initial drug exposure occurs often in humans. The drug-seeking/taking behaviors, and membrane properties and intrinsic excitability of IC pyramidal neurons were measured on withdrawal day (WD) 1 and WD 45-48 after limited vs extended cocaine intravenous self-administration (IVSA). RESULTS: We found higher cocaine-taking behaviors at the late withdrawal period after limited vs extended cocaine IVSA. We also found minor but significant effects of limited but not extended cocaine exposure on the kinetics and amplitude of action potentials on WD 45, in IC pyramidal neurons. CONCLUSION: Our results indicate potential high risks of relapse in young rats with limited but not extended drug exposure, although the adaptations detected in the IC may not be sufficient to explain the neural changes of higher drug-taking behaviors induced by limited cocaine IVSA.


Assuntos
Potenciais de Ação/efeitos dos fármacos , Administração Intravenosa , Cocaína/administração & dosagem , Comportamento de Procura de Droga/efeitos dos fármacos , Córtex Insular/efeitos dos fármacos , Potenciais de Ação/fisiologia , Administração Intravenosa/métodos , Animais , Inibidores da Captação de Dopamina/administração & dosagem , Esquema de Medicação , Comportamento de Procura de Droga/fisiologia , Córtex Insular/fisiologia , Masculino , Ratos , Ratos Sprague-Dawley , Autoadministração
10.
Drug Alcohol Depend ; 216: 108309, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32998090

RESUMO

BACKGROUND: Adolescence and early-adulthood are vulnerable developmental periods during which binge drinking can have long-lasting effects on brain function. However, little is known about the effects of binge drinking on the pyramidal cells of the prelimbic cortex (PrL) during early and protracted withdrawal periods. METHODS: In the present study, we performed whole-cell patch clamp recordings and dendritic spine staining to examine the intrinsic excitability, spontaneous excitatory post-synaptic currents (sEPSCs), and spine morphology of pyramidal cells in the PrL from rats exposed to chronic intermittent ethanol (CIE) during adolescence or early-adulthood. RESULTS: Compared to chronic intermittent water (CIW)-treated controls, the excitability of PrL-L5 pyramidal neurons was significantly increased 21 days after adolescent CIE but decreased 21 days after early-adult CIE. No changes of excitability in PrL Layer (L) 5 were detected 2 days after either adolescent or early-adulthood CIE. Interestingly, decreases in sEPSC amplitude and increases in thin spines ratio were detected 2 days after adolescent CIE. Furthermore, decreased frequency and amplitude of sEPSCs, accompanied by a decrease in the density of total spines and non-thin spines were observed 21 days after adolescent CIE. In contrast, increased frequency and amplitude of sEPSCs, accompanied by increased densities of total spines and non-thin spines were found 21 days after early adult CIE. CONCLUSION: CIE produced prolonged neuronal and synaptic alterations in PrL-L5, and the developmental stage, i.e., adolescence vs. early-adulthood when subjects receive CIE, is a key factor in determining the direction of these changes.


Assuntos
Etanol/administração & dosagem , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/crescimento & desenvolvimento , Células Piramidais/efeitos dos fármacos , Células Piramidais/fisiologia , Fatores Etários , Animais , Masculino , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Técnicas de Cultura de Órgãos , Ratos , Ratos Sprague-Dawley
11.
Neuropharmacology ; 180: 108310, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32950559

RESUMO

Prenatal alcohol exposure (PAE)-induced clinical symptoms have been widely reported but effective treatments are not yet available due to our limited knowledge of the neuronal mechanisms underlying behavioral outputs. Operant behaviors, including both goal-directed and habitual actions, are essential for everyday life. The dorsomedial striatum (DMS) and the dorsolateral striatum (DLS) have been identified as mediating each type of instrumental behavior, respectively. The current studies were designed to evaluate the effects of PAE (i.e., 3 g/kg, twice a day on gestational days 17-20) on goal-directed vs. habitual behaviors in both females and males during their adolescent and adult stages. We found that PAE-treated adult, but not adolescent, males display similar habitual oral sucrose self-administration but reduced goal-directed sucrose self-administration, compared to those treated by prenatal control (water) exposure (PCE). There were no differences in either habitual or goal-directed sucrose taking between PCE- vs. PAE-treated adolescent and adult females. These results indicate sex- and age-specific effects of PAE on operant behaviors. Further, whole-cell patch clamp recordings showed that the excitability of medium-sized spiny neurons (MSNs) in the posterior DMS (pDMS), but not the anterior DMS (aDMS), was significantly decreased in PAE-treated adult male rats. Notably, chemogenetic enhancement of MSN excitability in the pDMS by the DREADD agonist, compound 21, rescued the motivation of PAE-treated male adult rats. These data suggest that the pDMS may be a key neuronal substrate mediating the PAE-induced low motivation in male adults.


Assuntos
Corpo Estriado/efeitos dos fármacos , Etanol/toxicidade , Motivação/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/psicologia , Caracteres Sexuais , Fatores Etários , Animais , Condicionamento Operante/efeitos dos fármacos , Condicionamento Operante/fisiologia , Corpo Estriado/metabolismo , Etanol/administração & dosagem , Feminino , Masculino , Motivação/fisiologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Ratos , Ratos Sprague-Dawley , Autoadministração
12.
Eur J Med Chem ; 207: 112715, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32846322

RESUMO

This study aimed to improve the biological effectiveness and pharmacokinetic properties of chlorin e6, a second-generation photosensitizer (PS), for tumor photodynamic therapy (PDT). Herein, the novel 31-hexyloxy chlorin e6-based 152- or 131-amino acid derivatives 3a, 3b, 3c and 8 were synthesized and their photophysical properties and in vitro bioactivities such as phototoxicity against A549, HeLa and melanoma B16-F10 cells, reactive oxygen species (ROS) production and subcellular localization were evaluated. In addition, preferred target compounds were also investigated for their in vivo pharmacokinetic in SD rats and in vivo antitumor efficacies in C57BL/6 mice bearing melanoma B16-F10 cells. Apparently, simultaneous introduction of amino acid residue and n-hexyloxy chain in chlorin e6 made a significant improvement in photophysical properties, ROS production, in vitro and in vivo PDT efficacy. Encouragingly, all target compounds showed higher in vitro phototoxicity than Talaporfin, and that 3c (152-Lys) exhibited strongest phototoxicity and highest dark toxicity/phototoxicity ratio, followed by 8 (131-Asp), 3a (152-Asp) and 3b (152-Glu). Moreover, in vivo PDT antitumor efficacy of 3a, 3c and 8 was all better than that of Talaporfin, and that both 3c and 8 had stronger PDT antitumor efficiency than 3a. The overall results suggested that these novel 31-hexyloxy chlorin e6-based 152- or 131-amino acid derivatives, especially 3c and 8, might be potential antitumor candidate drugs for clinical treatment of melanoma by PDT.


Assuntos
Aminoácidos/química , Aminoácidos/farmacologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/química , Porfirinas/farmacologia , Células A549 , Aminoácidos/farmacocinética , Aminoácidos/uso terapêutico , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Clorofilídeos , Desenho de Fármacos , Células HeLa , Humanos , Masculino , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacocinética , Fármacos Fotossensibilizantes/uso terapêutico , Porfirinas/farmacocinética , Porfirinas/uso terapêutico , Ratos Sprague-Dawley
13.
Colloids Surf B Biointerfaces ; 194: 111144, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32535244

RESUMO

Histonedeacetylase inhibitor (HDACi) has great potential in targeted antitumor therapy by inhibiting tumor migration, invasion, and metastasis. As one of the typical HDACis, vorinostat (Suberoylanilide Hydroxamic Acid, SAHA) was approved as a therapeutic agent for cancer therapy, however, challenges remain due to their poor solubility, short half-life and low efficiency in cellular penetration. Considering the disadvantages of usual drug carriers, folate and vorinostat bound BSA nanogel (FVBN)was fabricated to implement higher solubility, stability, cellular uptake, and lipase-responsive release. With good dispersion and stability, FVBN significantly increased the cellular uptake of vorinostat through folate-mediated endocytosis. FVBN exhibited comparable cytotoxicity with free SAHA, and the growth of tumor cells was blocked in G1/G0 phase just like SAHA performed in cell cycle arrest tests. Moreover, FVBN not only effectively inhibited the growth of melanoma but also observably prevented pulmonary metastasis of melanoma. In the experiment against nude mice bearing solid ovarian cancer, FVBN showed excellent antitumor effect without liver damage, demonstrating the superiority of gelated and inner-lysosome triggered release strategies to the free SAHA, and it is promising to expand the scope of application of HDACi in clinical cancer therapy.


Assuntos
Antineoplásicos , Ácidos Hidroxâmicos , Vorinostat , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Inibidores de Histona Desacetilases/farmacologia , Humanos , Lisossomos , Camundongos , Camundongos Nus , Vorinostat/farmacologia
14.
IEEE J Biomed Health Inform ; 23(3): 1192-1204, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-29993902

RESUMO

Due to bone deformation and joint space narrowing in diseased hips, accurate segmentation for pelvis, and femur from hip computed tomography (CT) images remains a challenging task. Therefore, the paper presents a fully automatic segmentation framework for the pelvis and femur in both of healthy and diseased hips. The framework involves three steps: preprocessing, coarse segmentation, and refinement. It starts with a preprocessing procedure to extract the volume of interest (VOI) from original CT images. Then, a coarse segmentation of bone has been obtained by classifying the VOI as bone and nonbone parts based on conditional random field (CRF) model. Finally, the bone is further divided into the pelvis and femur using a patch-based refinement method. The innovation of this study is the novel patch-based refinement method that is particularly suitable for diseased hips. The refinement method starts from the boundary of coarse segmentation, and propagates to the neighbors only when the label is not consistent with the label of CRF-based classification, it increases the reliability of segmentation for diseased hips with bone deformation. We incorporate neighborhood information to label fusion so that final label estimation is more accurate and robust for diseased hips with joint space narrowing. In total, 60 CT data sets, which included 78 healthy hemi-hips and 42 diseased hemi-hips, were used, and three-fold cross validations were carried out. Compared to two state-of-the-art methods, our method achieved significantly increased segmentation accuracy for the diseased hemi-hips, and is, therefore, more suited for automatic segmentation of diseased hips.


Assuntos
Fêmur/diagnóstico por imagem , Quadril/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Pelve/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Humanos
15.
Int J Nanomedicine ; 14: 5527-5540, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31413561

RESUMO

Background: Nonspecific tumor targeting, potential relapse and metastasis of tumor after treatment are the main barriers in clinical photodynamic therapy (PDT) for cancer, hence, inhibiting relapse and metastasis of tumor is significant issues in clinic. Purpose: In this work, chidamide as a histone deacetylases inhibitor (HADCi) was bound onto a pH-responsive block polymer folate polyethylene glycol-b-poly(aspartic acid) (PEG-b-PAsp) grafted folate (FA-PEG-b-PAsp) to obtain the block polymer folate polyethylene glycol-b-poly(asparaginyl-chidamide) (FA-PEG-b-PAsp-chidamide, FPPC) as multimodal tumor-targeting drug-delivery carrier to inhibiting tumor cell proliferation and tumor metastasis in mice. Methods: Model photosensitizer pyropheophorbide-a (Pha) was encapsulated by FPPC in PBS to form the polymer micelles Pha@FPPC [folate polyethylene glycol-b-poly(asparaginyl-chidamide) micelles encapsulating Pha]. Pha@FPPC was characterized by transmission electron microscope and dynamic light scattering; also, antitumor activity in vivo and in vitro were investigated by determination of cellular ROS level, detection of cell apoptosis and cell cycle arrest, PDT antitumor activity in vivo and histological analysis. Results: With favorable and stable sphere morphology under transmission electron microscope (TEM) (~93.0 nm), Pha@FPPC greatly enhanced the cellular uptake due to its folate-mediated effective endocytosis by mouse melanoma B16-F10 cells and the yield of ROS in tumor cells induced by PDT, and mainly caused necrocytosis and blocked cell growth cycle not only in G2 phase but also in G1/G0 phase after PDT. Pha@FPPC exhibited lower dark cytotoxicity in vitro and a better therapeutic index because of its higher dark cytotoxicity/photocytotoxicity ratio. Moreover, Pha@FPPC not only significantly inhibited the growth of implanted tumor and prolonged the survival time of melanoma-bearing mice due to both its folate-mediated tumor-targeting and selectively accumulation at tumor site by EPR (enhanced permeability and retention)effect as micelle nanoparticles but also remarkably prevented pulmonary metastasis of mice melanoma after PDT compared to free Pha, demonstrating its dual antitumor characteristics of PDT and HDACi. Conclusion: As a folate-mediated and acid-activated chidamide-grafted drug-delivery carrier, FPPC may have great potential to inhibit tumor metastasis in clinical photodynamic treatment for cancer because of its effective and multimodal tumor-targeting performance as photosensitizer vehicle.


Assuntos
Aminopiridinas/química , Benzamidas/química , Ácido Fólico/uso terapêutico , Micelas , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Clorofila/análogos & derivados , Clorofila/farmacologia , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Ácido Fólico/farmacologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Camundongos Endogâmicos C57BL , Nanopartículas/química , Nanopartículas/ultraestrutura , Fármacos Fotossensibilizantes/farmacologia , Polietilenoglicóis/química , Espécies Reativas de Oxigênio/metabolismo
16.
Neurochem Res ; 33(10): 2166-70, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18633703

RESUMO

Electroacupuncture (EA) has been shown to modify the effects of various drugs of abuse, including alcohol. Inbred P rats were trained to drink alcohol voluntarily and then subjected to two periods of alcohol deprivation lasting 3 days. During the second deprivation, the rats received either EA or sham EA. The rats were pretreated with naltrexone (5 mg/kg) or saline 30 min before each of the EA or sham EA sessions. Approximately 6 h after the last naltrexone or saline treatment, the alcohol tubes were returned and alcohol and water intakes were recorded later at 2, 4, 6, and 24 h. Only EA led to a decrease in alcohol intake, which was most prominent at 6 and 24 h, and this inhibitory effect of EA was blocked by naltrexone, suggesting that activation of the endogenous opiate system may be responsible for EA's effects on alcohol intake in the alcohol-dependent iP rats.


Assuntos
Consumo de Bebidas Alcoólicas/fisiopatologia , Eletroacupuntura , Naltrexona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Receptores Opioides/fisiologia , Animais , Ratos , Receptores Opioides/efeitos dos fármacos
17.
Int J Comput Assist Radiol Surg ; 11(5): 817-26, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26646416

RESUMO

PURPOSE: Propose a fully automatic 3D segmentation framework to segment liver on challenging cases that contain the low contrast of adjacent organs and the presence of pathologies from abdominal CT images. METHODS: First, all of the atlases are weighted in the selected training datasets by calculating the similarities between the atlases and the test image to dynamically generate a subject-specific probabilistic atlas for the test image. The most likely liver region of the test image is further determined based on the generated atlas. A rough segmentation is obtained by a maximum a posteriori classification of probability map, and the final liver segmentation is produced by a shape-intensity prior level set in the most likely liver region. Our method is evaluated and demonstrated on 25 test CT datasets from our partner site, and its results are compared with two state-of-the-art liver segmentation methods. Moreover, our performance results on 10 MICCAI test datasets are submitted to the organizers for comparison with the other automatic algorithms. RESULTS: Using the 25 test CT datasets, average symmetric surface distance is [Formula: see text] mm (range 0.62-2.12 mm), root mean square symmetric surface distance error is [Formula: see text] mm (range 0.97-3.01 mm), and maximum symmetric surface distance error is [Formula: see text] mm (range 12.73-26.67 mm) by our method. Our method on 10 MICCAI test data sets ranks 10th in all the 47 automatic algorithms on the site as of July 2015. Quantitative results, as well as qualitative comparisons of segmentations, indicate that our method is a promising tool to improve the efficiency of both techniques. CONCLUSION: The applicability of the proposed method to some challenging clinical problems and the segmentation of the liver are demonstrated with good results on both quantitative and qualitative experimentations. This study suggests that the proposed framework can be good enough to replace the time-consuming and tedious slice-by-slice manual segmentation approach.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Fígado/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Abdome/diagnóstico por imagem , Atlas como Assunto , Humanos , Neoplasias Hepáticas/patologia , Probabilidade , Carga Tumoral
18.
Beijing Da Xue Xue Bao Yi Xue Ban ; 37(3): 273-7, 2005 Jun 18.
Artigo em Zh | MEDLINE | ID: mdl-15968318

RESUMO

OBJECTIVE: To investigate the effects of alpha1 adrenoceptor antagonist doxazosin on the growth of androgen-independent prostate cancer cell PC-3 transplanted in nude mice. METHODS: PC-3 cells xenografts were transplanted (s.c.) in nude mice, and thirty xenografts were established successively. They were then randomly divided into 5 groups: A (control group), B (doxazosin 3 mg/kg), C (doxazosin 10 mg/kg), D (doxazosin 30 mg/kg), and E (doxazosin 100 mg/kg). Seven days after implantation, doxazosin was administered in sterile water by oral gavage, and the volumes of the transplanted tumors were measured during the therapy twice a week. All the mice were sacrificed after two weeks of doxazosin administration; the tumors were resected to do the following research. Immunohistochemistry of Ki67 and terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling (TUNEL) was done to study the effects of doxazosin on the proliferation and apoptosis of prostate cancer cells; moreover, we also used Western blotting to study the protein expression of Smad-4 and IkappaB alpha. RESULTS: Nude mouse experiments showed that the in vivo doxazosin administration induced a notable decrease in the volumes of prostate cancer xenografts compared with the control group, and the tumor weights were also decreased. Interestingly enough, administration of doxazosin at higher concentrations (10, 30, 100 mg/kg) did not have further effect on tumor suppression. The percentage of PC-3 TUNEL positive cells was significantly higher than that of the control group; while the doxazosin treated groups and the control group did not have statistical difference on the percentage of Ki67 positive cells. In doxazosin treated groups Smad-4 and IkappaB alpha expressions were higher than that of the control group. CONCLUSION: Doxazosin can inhibit the growth of the prostate xenografts in the nude mice by inducing apoptosis without affecting the cell proliferation. Activation of transforming growth factor beta1 (TGF-beta1) signaling pathway may be the mechanism underlying doxazosin-mediated apoptosis.


Assuntos
Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Doxazossina/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas Adrenérgicos alfa/uso terapêutico , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Doxazossina/farmacologia , Feminino , Proteínas I-kappa B/biossíntese , Proteínas I-kappa B/genética , Antígeno Ki-67/biossíntese , Antígeno Ki-67/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Inibidor de NF-kappaB alfa , Transplante de Neoplasias , Neoplasias da Próstata/patologia , Transdução de Sinais , Proteína Smad4/biossíntese , Proteína Smad4/genética , Fator de Crescimento Transformador beta1/metabolismo
19.
Indian J Orthop ; 49(4): 442-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26229166

RESUMO

BACKGROUND: Severe developmental dysplasia of the hip is a surgical challenge. The purpose of this study is to describe the cementless arthroplasty with a distal femoral shortening osteotomy for Crowe type IV developmental hip dysplasia and to report the results of this technique. MATERIALS AND METHODS: 12 patients (2 male and 10 female) of Crowe type IV developmental hip dysplasia operated between January 2005 and December 2010 were included in the study. All had undergone cementless arthroplasty with a distal femoral shortening osteotomy. Acetabular cup was placed at the level of the anatomical position in all the hips. The clinical outcomes were assessed and radiographs were reviewed to evaluate treatment effects. RESULTS: The mean followup for the 12 hips was 52 months (range 36-82 months). The mean Harris hip score improved from 41 points (range 28-54) preoperatively to 85 points (range 79-92) at the final followup. The mean length of bone removed was 30 mm (range 25-40 mm). All the osteotomies healed in a mean time of 13 weeks (range 10-16 weeks). There were no neurovascular injuries, pulmonary embolism or no infections. CONCLUSION: Our study suggests that cementless arthroplasty with a distal femoral shortening is a safe and effective procedure for severe developmental dysplasia of the hip.

20.
Neuron ; 83(6): 1453-67, 2014 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-25199705

RESUMO

Glutamatergic projections from the medial prefrontal cortex (mPFC) to nucleus accumbens (NAc) contribute to cocaine relapse. Here we show that silent synapse-based remodeling of the two major mPFC-to-NAc projections differentially regulated the progressive increase in cue-induced cocaine seeking after withdrawal (incubation of cocaine craving). Specifically, cocaine self-administration in rats generated AMPA receptor-silent glutamatergic synapses within both infralimbic (IL) and prelimbic mPFC (PrL) to NAc projections, measured after 1 day of withdrawal. After 45 days of withdrawal, IL-to-NAc silent synapses became unsilenced/matured by recruiting calcium-permeable (CP) AMPARs, whereas PrL-to-NAc silent synapses matured by recruiting non-CP-AMPARs, resulting in differential remodeling of these projections. Optogenetic reversal of silent synapse-based remodeling of IL-to-NAc and PrL-to-NAc projections potentiated and inhibited, respectively, incubation of cocaine craving on withdrawal day 45. Thus, pro- and antirelapse circuitry remodeling is induced in parallel after cocaine self-administration. These results may provide substrates for utilizing endogenous antirelapse mechanisms to reduce cocaine relapse.


Assuntos
Transtornos Relacionados ao Uso de Cocaína/fisiopatologia , Fissura/fisiologia , Núcleo Accumbens/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Sinapses/fisiologia , Animais , Comportamento de Procura de Droga/fisiologia , Eletrofisiologia , Masculino , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiopatologia , Plasticidade Neuronal/fisiologia , Núcleo Accumbens/efeitos dos fármacos , Optogenética , Córtex Pré-Frontal/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Sinapses/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA