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1.
Sensors (Basel) ; 24(12)2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38931739

RESUMO

The accurate perception of external environment information through the robot foot is crucial for the mobile robot to evaluate its ability to traverse terrain. Adequate foot-end contact signals can provide robust support for robot motion control and decision-making processes. The shape and uncertain rotation of the wheel-legged robot foot end represent a significant challenge to sensing the robot foot-end contact state, which current foot-end sensing schemes cannot solve. This paper presents a sensing method for the tire stress field of wheel-legged robots. A finite element analysis was conducted to study the deformation characteristics of the foot-end tire under force. Based on this analysis, a heuristic contact position estimator was designed that utilizes symmetrical deformation characteristics. Strain sensors, arranged in an array, extract the deformation information on the inner surface of the tire at a frequency of 200 Hz. The contact position estimator reduces the dimensionality of the data and fits the eigenvalues to the estimated contact position. Using support vector regression, the force estimator utilizes the estimated contact position and sensor signal to estimate the normal reaction force, designated as FZ. The sensing system is capable of detecting the contact position on the wheel circumference (with a root mean square error of 1.150°), as well as the normal force of 160 N on the Z axis (with a root mean square error of 6.04%). To validate the efficacy of the sensor detection method, a series of randomized and repeated experiments were conducted on a self-constructed test platform. This novel approach offers a promising avenue for perceiving contact states in wheel-legged robots.

2.
Mol Psychiatry ; 26(8): 4544-4560, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33299135

RESUMO

Chronic cerebral hypoperfusion is associated with vascular dementia (VaD). Cerebral hypoperfusion may initiate complex molecular and cellular inflammatory pathways that contribute to long-term cognitive impairment and memory loss. Here we used a bilateral common carotid artery stenosis (BCAS) mouse model of VaD to investigate its effect on the innate immune response-particularly the inflammasome signaling pathway. Comprehensive analyses revealed that chronic cerebral hypoperfusion induces a complex temporal expression and activation of inflammasome components and their downstream products (IL-1ß and IL-18) in different brain regions, and promotes activation of apoptotic and pyroptotic cell death pathways. Polarized glial-cell activation, white-matter lesion formation and hippocampal neuronal loss also occurred in a spatiotemporal manner. Moreover, in AIM2 knockout mice we observed attenuated inflammasome-mediated production of proinflammatory cytokines, apoptosis, and pyroptosis, as well as resistance to chronic microglial activation, myelin breakdown, hippocampal neuronal loss, and behavioral and cognitive deficits following BCAS. Hence, we have demonstrated that activation of the AIM2 inflammasome substantially contributes to the pathophysiology of chronic cerebral hypoperfusion-induced brain injury and may therefore represent a promising therapeutic target for attenuating cognitive impairment in VaD.


Assuntos
Disfunção Cognitiva , Demência Vascular , Substância Branca , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Inflamassomos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Substância Branca/metabolismo
3.
J Clin Lab Anal ; 36(7): e24526, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35657334

RESUMO

BACKGROUND: We aimed to analyze the level of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) in neutrophils of ischemic stroke (IS) patients at different stages, together with its roles in neutrophils. PATIENTS AND METHODS: Sixty-seven patients were classified into acute phase group (n = 19), subacute phase group (n = 28), and stable phase group (n = 20), and 20 healthy individuals who had received physical examination at the same time period as healthy control. We then analyzed the expression level of CEACAM1 and cell viability in CEACAM1 positive and CEACAM1 negative neutrophils by flow cytometry and the content of plasma CEACAM1, neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinases-9 (MMP-9) was measured using enzyme-linked immunosorbent assay (ELISA), while that of interleukin-10 (IL-10) and tumor necrosis factor (TNF) was determined using a Human Enhanced Sensitivity Flex set. RESULTS: Compared with healthy control, the percentage of CEACAM1 positive neutrophils in IS patients showed a significant increase, and a significant increase was also noticed in the content of plasma CEACAM1 at the subacute stage. Reduction in cell viability was observed in CEACAM1 positive neutrophils compared with CEACAM1 negative counterparts. There was a positive correlation between CEACAM1 expression rate in neutrophils and plasma CEACAM1 and IL-10 content in the subacute group. Compared with acute group and healthy control group, there was an instinct increase in the level of plasma MMP-9 and NGAL in subacute group. CONCLUSIONS: Our data showed that there was a rapid increase of CEACAM1 in neutrophils at the acute stage of IS. We speculated that CEACAM1 may serve as an inhibitory regulator involving in the progression of IS.


Assuntos
Antígenos CD , Antígeno Carcinoembrionário , Moléculas de Adesão Celular , AVC Isquêmico , Antígenos CD/metabolismo , Antígeno Carcinoembrionário/metabolismo , Moléculas de Adesão Celular/metabolismo , Humanos , Mediadores da Inflamação , Interleucina-10/metabolismo , Lipocalina-2 , Metaloproteinase 9 da Matriz/metabolismo
4.
J Transl Med ; 19(1): 465, 2021 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-34774066

RESUMO

OBJECTIVES: Toll-like receptors (TLRs) on neutrophils play a crucial role in detecting pathogens and organ/tissue injury in acute-on-chronic liver failure (ACLF). However, little is known about the exact mechanisms and potential signalling pathways. The aim of this study was to investigate alterations in TLR signalling pathways in neutrophils of ACLF patients. METHODS: Twenty-seven patients with compensated cirrhosis (n = 9), decompensated cirrhosis (n = 9) and ACLF (n = 9) were enrolled in the study. Neutrophils were isolated, and alterations in TLR signalling pathways were evaluated using an RT2 Profiler™ PCR Array. The fold change for each gene (2(-∆∆CT)) was compared among the groups. Genes with a fold change ratio of ≥ 2 or ≤ 0.5 along with a p value of < 0.05 were considered to be differentially expressed. RESULTS: A total of 17 genes were upregulated in neutrophils from patients with compensated cirrhosis and were mainly distributed in adaptors, TLR-interacting proteins and downstream pathways. Six genes were detected in patients with decompensated cirrhosis. A trend of downregulation of genes in the TLR signalling pathway was observed in neutrophils of patients with cirrhosis and ACLF. TLR3, IFNG, IL1B, TBK1, CCL2 and LTA were downregulated in neutrophils. Moreover, CD14 and IL10 were upregulated in neutrophils of ACLF patients. CONCLUSIONS: TLR signalling pathway genes were differentially regulated in neutrophils between cirrhosis and ACLF. In ACLF patients, defective expression of TLR3 and IFN, along with enhanced CD14 and IL10 expression, was characterized by transcriptional alterations of neutrophils.


Assuntos
Insuficiência Hepática Crônica Agudizada , Insuficiência Hepática Crônica Agudizada/genética , Fibrose , Humanos , Cirrose Hepática , Neutrófilos , Transdução de Sinais/genética
5.
Am J Physiol Regul Integr Comp Physiol ; 320(1): R55-R68, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33085911

RESUMO

In fishes, branchial cytosolic carbonic anhydrase (CA) plays an important role in ion and acid-base regulation. The Ca17a isoform in zebrafish (Danio rerio) is expressed abundantly in Na+-absorbing/H+-secreting H+-ATPase-rich (HR) cells. The present study aimed to identify the role of Ca17a in ion and acid-base regulation across life stages using CRISPR/Cas9 gene editing. However, in preliminary experiments, we established that ca17a knockout is lethal with ca17a-/- mutants exhibiting a significant decrease in survival beginning at ∼12 days postfertilization (dpf) and with no individuals surviving past 19 dpf. Based on these findings, we hypothesized that ca17a-/- mutants would display alterations in ion and acid-base balance and that these physiological disturbances might underlie their early demise. Na+ uptake rates were significantly increased by up to 300% in homozygous mutants compared with wild-type individuals at 4 and 9 dpf; however, whole body Na+ content remained constant. While Cl- uptake was significantly reduced in ca17a-/- mutants, Cl- content was unaffected. Reduction of CA activity by Ca17a morpholino knockdown or ethoxzolamide treatments similarly reduced Cl- uptake, implicating Ca17a in the mechanism of Cl- uptake by larval zebrafish. H+ secretion, O2 consumption, CO2 excretion, and ammonia excretion were generally unaltered in ca17a-/- mutants. In conclusion, while the loss of Ca17a caused marked changes in ion uptake rates, providing strong evidence for a Ca17a-dependent Cl- uptake mechanism, the underlying causes of the lethality of this mutation in zebrafish remain unclear.


Assuntos
Equilíbrio Ácido-Base , Anidrases Carbônicas/deficiência , Cloretos/metabolismo , Técnicas de Inativação de Genes , Sódio/metabolismo , Proteínas de Peixe-Zebra/deficiência , Peixe-Zebra/metabolismo , Animais , Animais Geneticamente Modificados , Sistemas CRISPR-Cas , Anidrases Carbônicas/genética , Concentração de Íons de Hidrogênio , Transporte de Íons , Mutação , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
6.
BMC Gastroenterol ; 21(1): 429, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34789156

RESUMO

BACKGROUND: Acute-on-chronic liver failure (ACLF) is a comprehensive syndrome characterized by an acute deterioration of liver function and high short-term mortality rates in patients with chronic liver disease. Whether plasma soluble urokinase plasminogen activator receptor (suPAR) is a suitable biomarker for the prognosis of patients with ACLF remains unknown. METHOD: A prospective cohort of 282 patients with ACLF from three hospitals in China was included. 88.4% of the group was hepatitis B virus-related ACLF (HBV-related ACLF). Cox regression was used to assess the impact of plasma suPAR and other factors on 30- and 90-day mortality. Reactive oxygen species (ROS) production were detected to explore the role of suPAR in regulating neutrophil function in HBV-related ACLF. RESULT: There was no difference in plasma suPAR levels between HBV-related and non-HBV-related ACLF. Patients with clinical complications had higher suPAR levels than those without these complications. A significant correlation was also found between suPAR and prognostic scores, infection indicators and inflammatory cytokines. Cox's regression multivariate analysis identified suPAR ≥ 14.7 ng/mL as a predictor for both day 30 and 90 mortality (Area under the ROC curve: 0.751 and 0.742 respectively), independent of the MELD and SOFA scores in patients with ACLF. Moreover, we firstly discovered suPAR enhanced neutrophil ROS production under E.coli stimulation in patients with HBV-related ACLF. CONCLUSIONS: suPAR was a useful independent biomarker of short-term outcomes in patients with ACLF and might play a key role in the pathogenesis. Trial registration CNT, NCT02965560.


Assuntos
Insuficiência Hepática Crônica Agudizada , Humanos , Prognóstico , Estudos Prospectivos , Curva ROC , Espécies Reativas de Oxigênio , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Estudos Retrospectivos
7.
Int J Mol Sci ; 21(12)2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32575820

RESUMO

Although butylidenephthalide (BP) is an efficient anticancer drug, its poor bioavailability renders it ineffective for treating drug-resistant brain tumors. However, this problem is overcome through the use of noninvasive delivery systems, including intranasal administration. Herein, the bioavailability, drug stability, and encapsulation efficiency (EE, up to 95%) of BP were improved by using cyclodextrin-encapsulated BP in liposomal formulations (CDD1). The physical properties and EE of the CDD1 system were investigated via dynamic light scattering, transmission electron microscopy, UV-Vis spectroscopy, and nuclear magnetic resonance spectroscopy. The cytotoxicity was examined via MTT assay, and the cellular uptake was observed using fluorescence microscopy. The CDD1 system persisted for over 8 h in tumor cells, which was a considerable improvement in the retention of the BP-containing cyclodextrin or the BP-containing liposomes, thereby indicating a higher BP content in CDD1. Nanoscale CDD1 formulations were administered intranasally to nude mice that had been intracranially implanted with temozolomide-resistant glioblastoma multiforme cells, resulting in increased median survival time. Liquid chromatography-mass spectrometry revealed that drug biodistribution via intranasal delivery increased the accumulation of BP 10-fold compared to oral delivery methods. Therefore, BP/cyclodextrin/liposomal formulations have potential clinical applications for treating drug-resistant brain tumors.


Assuntos
Antineoplásicos/farmacocinética , Encéfalo/metabolismo , Sistemas de Liberação de Medicamentos , Anidridos Ftálicos/farmacocinética , Animais , Antineoplásicos/administração & dosagem , Disponibilidade Biológica , Encéfalo/efeitos dos fármacos , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Ciclodextrinas/química , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Lipossomos/química , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Anidridos Ftálicos/administração & dosagem , Distribuição Tecidual
8.
Pharmacol Res ; 139: 50-61, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30385365

RESUMO

Annually, 48,000 people die from pancreatic ductal adenocarcinoma (PDAC), ranking it the fourth among cancer-related deaths in the United States. Currently, anti-cancer drugs are not effective against PDAC, and only extends survival by 3 months. Aberrant DNA methylation has been shown to play an important role during carcinogenesis in PDAC, with approximately 80% of tumor overexpressing the DNA methyltransferase 1 (DNMT1) protein. In the present study, we used DNMTs as a screening platform to find a new DNMT inhibitor, n-butylidenephthalide (n-BP), which is identified from a Chinese herbal drug. n-BP could inhibit DNMT1 expression in both dose-dependent and time-dependent manner. It also displays an effect in suppressing growth of PDAC cells and inducing cell cycle arrest at G0/G1 phase leading apoptosis. Growth suppression can be restored by the overexpression of DNMT1 in PDAC cells. Furthermore, we found n-BP-mediated DNMT1 suppression influenced the protein stability rather than changing the RNA expression. Through microarray studies, we found that the patched domain contained 4 (PTCHD4) is the potential downstream gene of DNMT1. Following silencing of PTCHD4 expression by siRNA, n-BP decreased tumor growth inhibition. Finally, in vivo, two animal models were used to evaluate the efficacy and survival after n-BP treatment by interstitial control release polymer delivery. The results show that n-BP could effectively inhibit PDAC tumor volume growth and extend animal survival. In summary, n-BP may inhibit the growth of human PDAC cells though reducing DNMT1 and increasing the expression of PTCHD4 both in vitro and in vivo.


Assuntos
Carcinoma Ductal Pancreático/tratamento farmacológico , Metilases de Modificação do DNA/antagonistas & inibidores , Proteínas Hedgehog/antagonistas & inibidores , Neoplasias Pancreáticas/tratamento farmacológico , Anidridos Ftálicos/farmacologia , Anidridos Ftálicos/uso terapêutico , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral , Metilases de Modificação do DNA/genética , Metilases de Modificação do DNA/metabolismo , Epigênese Genética , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Polímeros/farmacologia , Polímeros/uso terapêutico , RNA Interferente Pequeno/genética , Proteínas Repressoras/genética
9.
Molecules ; 24(22)2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31752262

RESUMO

Fibrosis is a type of chronic organ failure, resulting in the excessive secretion of extracellular matrix (ECM). ECM protects wound tissue from infection and additional injury, and is gradually degraded during wound healing. For some unknown reasons, myofibroblasts (the cells that secrete ECM) do not undergo apoptosis; this is associated with the continuous secretion of ECM and reduced ECM degradation even during de novo tissue formation. Thus, matrix metalloproteinases (MMPs) are considered to be a potential target of fibrosis treatment because they are the main groups of ECM-degrading enzymes. However, MMPs participate not only in ECM degradation but also in the development of various biological processes that show the potential to treat diseases such as stroke, cardiovascular diseases, and arthritis. Therefore, treatment involving the targeting of MMPs might impede typical functions. Here, we evaluated the links between these MMP functions and possible detrimental effects of fibrosis treatment, and also considered possible approaches for further applications.


Assuntos
Fibrose/etiologia , Fibrose/metabolismo , Metaloproteinases da Matriz/metabolismo , Metaloproteinases da Matriz/farmacologia , Animais , Suscetibilidade a Doenças , Ativação Enzimática , Matriz Extracelular/metabolismo , Fibrose/tratamento farmacológico , Regulação da Expressão Gênica , Humanos , Imunomodulação , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/uso terapêutico , Miofibroblastos/metabolismo , Neovascularização Patológica , Especificidade de Órgãos/genética , Proteólise , Cicatrização
10.
Int J Mol Sci ; 19(10)2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30287739

RESUMO

Pulmonary fibrosis is a fatal respiratory disease that gradually leads to dyspnea, mainly accompanied by excessive collagen production in the fibroblast and myofibroblast through mechanisms such as abnormal alveolar epithelial cells remodeling and stimulation of the extracellular matrix (ECM). Our results show that a small molecule, butylidenephthalide (BP), reduces type I collagen (COL1) expression in Transforming Growth Factor beta (TGF-ß)-induced lung fibroblast without altering downstream pathways of TGF-ß, such as Smad phosphorylation. Treatment of BP also reduces the expression of transcription factor Sex Determining Region Y-box 2 (SOX2), and the ectopic expression of SOX2 overcomes the inhibitory actions of BP on COL1 expression. We also found that serial deletion of the SOX2 binding site on 3'COL1 promoter results in a marked reduction in luciferase activity. Moreover, chromatin immunoprecipitation, which was found on the SOX2 binding site of the COL1 promoter, decreases in BP-treated cells. In an in vivo study using a bleomycin-induced pulmonary fibrosis C57BL/6 mice model, mice treated with BP displayed reduced lung fibrosis and collagen deposition, recovering in their pulmonary ventilation function. The reduction of SOX2 expression in BP-treated lung tissues is consistent with our findings in the fibroblast. This is the first report that reveals a non-canonical regulation of COL1 promoter via SOX2 binding, and contributes to the amelioration of pulmonary fibrosis by BP treatment.


Assuntos
Anidridos Ftálicos/farmacologia , Fibrose Pulmonar/metabolismo , Animais , Linhagem Celular , Colágeno Tipo I/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Anidridos Ftálicos/uso terapêutico , Regiões Promotoras Genéticas , Fibrose Pulmonar/tratamento farmacológico , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo
11.
Molecules ; 23(2)2018 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-29382106

RESUMO

Traditional Chinese medicine has been practiced for centuries in East Asia. Herbs are used to maintain health and cure disease. Certain Chinese herbs are known to protect and improve the brain, memory, and nervous system. To apply ancient knowledge to modern science, some major natural therapeutic compounds in herbs were extracted and evaluated in recent decades. Emerging studies have shown that herbal compounds have neuroprotective effects or can ameliorate neurodegenerative diseases. To understand the mechanisms of herbal compounds that protect against neurodegenerative diseases, we summarize studies that discovered neuroprotection by herbal compounds and compound-related mechanisms in neurodegenerative disease models. Those compounds discussed herein show neuroprotection through different mechanisms, such as cytokine regulation, autophagy, endoplasmic reticulum (ER) stress, glucose metabolism, and synaptic function. The interleukin (IL)-1ß and tumor necrosis factor (TNF)-α signaling pathways are inhibited by some compounds, thus attenuating the inflammatory response and protecting neurons from cell death. As to autophagy regulation, herbal compounds show opposite regulatory effects in different neurodegenerative models. Herbal compounds that inhibit ER stress prevent neuronal death in neurodegenerative diseases. Moreover, there are compounds that protect against neuronal death by affecting glucose metabolism and synaptic function. Since the progression of neurodegenerative diseases is complicated, and compound-related mechanisms for neuroprotection differ, therapeutic strategies may need to involve multiple compounds and consider the type and stage of neurodegenerative diseases.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Doenças Neurodegenerativas , Neurônios/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Animais , Morte Celular/efeitos dos fármacos , Citocinas/metabolismo , Humanos , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Neurônios/patologia
12.
Cancer Sci ; 108(4): 604-611, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28403546

RESUMO

Delta-aminolevulinate dehydratase (ALAD) catalyzes the second step in the biosynthesis of heme and is also an endogenous inhibitor of the 26S proteasome. The role of ALAD in breast cancer progression is still unclear. In this study, we found that the expression of ALAD was downregulated in breast cancer tissues compared with adjacent normal breast tissues. Enhanced ALAD expression was associated with a favorable outcome in patients with breast cancer. Overexpression of ALAD suppresses breast cancer cell proliferation and invasion and inhibits the epithelial-mesenchymal transition phenotype. Furthermore, we found that ALAD regulates transforming growth factor-ß-mediated breast cancer progression. This finding suggests that ALAD might be a potential biomarker for breast cancer that suppresses breast cancer progression by regulating transforming growth factor-ß-mediated epithelial-mesenchymal transition.


Assuntos
Neoplasias da Mama/genética , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Sintase do Porfobilinogênio/genética , Western Blotting , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/enzimologia , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/genética , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Feminino , Humanos , Microscopia de Fluorescência , Sintase do Porfobilinogênio/metabolismo , Prognóstico , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
13.
Teach Learn Med ; 29(2): 162-172, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27997224

RESUMO

Phenomenon: Peer learning has many benefits and can assist students in gaining the educational skills required in future years when they become teachers themselves. Peer learning may be particularly useful in clinical learning environments, where students report feeling marginalized, overwhelmed, and unsupported. Educational interventions often fail in the workplace environment, as they are often conceived in the "ideal" rather than the complex, messy real world. This work sought to explore barriers and facilitators to implementing peer learning activities in a clinical curriculum. APPROACH: Previous peer learning research results and a matrix of empirically derived peer learning activities were presented to local clinical education experts to generate discussion around the realities of implementing such activities. Potential barriers and limitations of and strategies for implementing peer learning in clinical education were the focus of the individual interviews. FINDINGS: Thematic analysis of the data identified three key considerations for real-world implementation of peer learning: culture, epistemic authority, and the primacy of patient-centered care. Strategies for peer learning implementation were also developed from themes within the data, focusing on developing a culture of safety in which peer learning could be undertaken, engaging both educators and students, and establishing expectations for the use of peer learning. Insights: This study identified considerations and strategies for the implementation of peer learning activities, which took into account both educator and student roles. Reported challenges were reflective of those identified within the literature. The resultant framework may aid others in anticipating implementation challenges. Further work is required to test the framework's application in other contexts and its effect on learner outcomes.


Assuntos
Educação de Graduação em Medicina/métodos , Aprendizagem , Grupo Associado , Aprendizagem Baseada em Problemas , Estudantes de Medicina , Feminino , Humanos , Masculino , Pesquisa Qualitativa
14.
Hepatobiliary Pancreat Dis Int ; 16(4): 412-417, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28823372

RESUMO

BACKGROUND: Stricture formation at the bilioenteric anastomosis is a rare but important postoperative complication. However, information on this complication is lacking in the literature. In the present study, we aimed to assess its prevalence and predictive factors, and report our experience in managing bilioenteric anastomotic strictures over a ten-year period. METHODS: A total of 420 patients who had undergone bilioenteric anastomosis due to benign or malignant tumors between February 2001 and December 2011 were retrospectively reviewed. Univariate and multivariate modalities were used to identify predictive factors for anastomotic stricture occurrence. Furthermore, the treatment of anastomotic stricture was analyzed. RESULTS: Twenty-one patients (5.0%) were diagnosed with bilioenteric anastomotic stricture. There were 12 males and 9 females with a mean age of 61.6 years. The median time after operation to anastomotic stricture was 13.6 months (range, 1 month to 5 years). Multivariate analysis identified that surgeon volume (≤30 cases) (odds ratio: -1.860; P=0.044) was associated with the anastomotic stricture while bile duct size (>6 mm) (odds ratio: 2.871; P=0.0002) had a negative association. Balloon dilation was performed in 18 patients, biliary stenting in 6 patients, and reoperation in 4 patients. Five patients died of tumor recurrence, and one of heart disease. CONCLUSIONS: Bilioenteric anastomotic stricture is an uncommon complication that can be treated primarily by interventional procedures. Bilioenteric anastomosis may be performed by a surgeon in his earlier training period under the guidance of an experienced surgeon. Bile duct size >6 mm may play a protective role.


Assuntos
Procedimentos Cirúrgicos do Sistema Biliar/efeitos adversos , Colestase/epidemiologia , Colestase/terapia , Neoplasias do Sistema Digestório/cirurgia , Idoso , Anastomose Cirúrgica , Procedimentos Cirúrgicos do Sistema Biliar/mortalidade , Distribuição de Qui-Quadrado , China/epidemiologia , Colecistectomia/efeitos adversos , Coledocostomia/efeitos adversos , Colestase/diagnóstico , Colestase/mortalidade , Constrição Patológica , Neoplasias do Sistema Digestório/mortalidade , Neoplasias do Sistema Digestório/patologia , Dilatação , Feminino , Humanos , Jejunostomia/efeitos adversos , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Prevalência , Reoperação , Estudos Retrospectivos , Fatores de Risco , Stents , Fatores de Tempo , Resultado do Tratamento
15.
Int J Mol Sci ; 18(2)2017 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-28208648

RESUMO

Glioblastoma (GBM) is one of the most common and aggressive types of brain tumor. Due to its highly recurrent rate and poor prognosis, the overall survival time with this type of tumor is only 20-21 months. Recent knowledge suggests that its recurrence is in part due to the presence of cancer stem cells (CSCs), which display radioresistant, chemoresistant, self-renewal and tumorigenic potential. Enhancers of Zeste 2 (EZH2) and AXL receptor tyrosine kinase (AXL) are both highly expressed in GBM. Additionally, they are an essential regulator involved in CSCs maintenance, migration, invasion, epithelial-to-mesenchymal transition (EMT), stemness, metastasis and patient survival. In this study, we used a small molecule, n-butylidenephthalide (BP), to assess the anti-GBM stem-like cells potential, and then tried to find out the associated genes involved with regulation in migration and invasion. We demonstrated that BP reduced the expression of AXL and stemness related genes in a dose-dependent manner. The migratory and invasive capabilities of GBM stem-like cells could be reduced by AXL/EZH2. Finally, in the overexpression of AXL, EZH2 and Sox2 by transfection in GBM stem-like cells, we found that AXL/EZH2/TGF-ꞵ1, but not Sox2, might be a key regulator in tumor invasion, migration and EMT. These results might help in the development of a new anticancer compound and can be a target for treating GBM.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Anidridos Ftálicos/farmacologia , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Biomarcadores , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Autorrenovação Celular/efeitos dos fármacos , Autorrenovação Celular/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Modelos Biológicos , Fenótipo , Receptor Tirosina Quinase Axl
16.
Cell Mol Life Sci ; 72(5): 983-97, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25213357

RESUMO

Mitochondrial ferritin (FtMt) has a significant effect on the regulation of cytosolic and mitochondrial iron levels. However, because of the deficiency of iron regulatory elements (IRE) in FtMt's gene sequence, the exact function of FtMt remains unclear. In the present study, we found that FtMt dramatically inhibited SH-SY5Y cell proliferation and tumor growth in nude mice. Interestingly, excess FtMt did not adversely affect the development of drosophila. Additionally, we found that the expression of FtMt in human normal brain tissue was significantly higher than that of neuroblastoma, but not higher than that of neurospongioma. However, the expression of transferrin receptor 1 is completely opposite. We therefore hypothesized that increased expression of FtMt may negatively affect the vitality of neuronal tumor cells. Therefore, we further investigated the underlying mechanisms of FtMt's inhibitory effects on neuronal tumor cell proliferation. As expected, FtMt overexpression disturbed the iron homeostasis of tumor cells and significantly downregulated the expression of proliferating cell nuclear antigen. Moreover, FtMt affected cell cycle, causing G1/S arrest by modifying the expression of cyclinD1, cyclinE, Cdk2, Cdk4 and p21. Remarkably, FtMt strongly upregulated the expression of the tumor suppressors, p53 and N-myc downstream-regulated gene-1 (NDRG1), but dramatically decreased C-myc, N-myc and p-Rb levels. This study demonstrates for the first time a new role and mechanism for FtMt in the regulation of cell cycle. We thus propose FtMt as a new candidate target for inhibiting neuronal tumor cell proliferation. Appropriate regulation of FtMt expression may prevent tumor cell growth. Our study may provide a new strategy for neuronal cancer therapy.


Assuntos
Ferritinas/metabolismo , Mitocôndrias/metabolismo , Animais , Apoptose , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Ciclina D1/metabolismo , Ciclina E/metabolismo , Quinase 2 Dependente de Ciclina/metabolismo , Ferritinas/genética , Pontos de Checagem da Fase G1 do Ciclo Celular , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteína do Retinoblastoma/metabolismo , Proteína Supressora de Tumor p53/metabolismo
17.
Adv Health Sci Educ Theory Pract ; 21(3): 659-76, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26662035

RESUMO

This study explored the contribution of peer-assisted learning (PAL) in the development of evaluative judgement capacity; the ability to understand work quality and apply those standards to appraising performance. The study employed a mixed methods approach, collecting self-reported survey data, observations of, and reflective interviews with, the medical students observed. Participants were in their first year of clinical placements. Data were thematically analysed. Students indicated that PAL contributed to both the comprehension of notions of quality, and the practice of making comparisons between a given performance and the standards. Emergent themes included peer story-telling, direct observation of performance, and peer-based feedback, all of which helped students to define 'work quality'. By participating in PAL, students were required to make comparisons, therefore using the standards of practice and gaining a deeper understanding of them. The data revealed tensions in that peers were seen as less threatening than supervisors with the advantage of increasing learners' appetites for thoughtful 'intellectual risk taking'. Despite this reported advantage of peer engagement, learners still expressed a preference for feedback from senior teachers as more trusted sources of clinical knowledge. While this study suggests that PAL already contributes to the development of evaluative judgement, further steps could be taken to formalise PAL in clinical placements to improve learners' capacity to make accurate judgements on the performance of self and others. Further experimental studies are necessary to confirm the best methods of using PAL to develop evaluative judgement. This may include both students and educators as instigators of PAL in the workplace.


Assuntos
Educação Médica/métodos , Avaliação Educacional/métodos , Julgamento , Grupo Associado , Competência Clínica/normas , Educação Médica/normas , Feminino , Feedback Formativo , Humanos , Aprendizagem , Masculino , Estudantes de Medicina/psicologia
18.
Nanotechnology ; 26(5): 055604, 2015 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-25590263

RESUMO

In this paper we describe the selective growth of ZnO nanorods (NRs) on top of hydrophobic Si NR arrays. The periodic Si NR arrays, prepared through electroless chemical etching and HF treatment, functioned as hydrophobic substrates. Droplets containing ZnO seeds could be positioned on the Si NR arrays, causing the ZnO seeds to deposit selectively upon them, with n-ZnO NR/p-Si NR array heterojunctions ultimately forming after hydrothermal growth of ZnO NRs. Because of compensation for the difference in refractive index between air and the Si substrate, the n-ZnO NR/p-Si NR arrays exhibited excellent absorption ability in the visible range. Devices based on these n-ZnO NR/p-Si NR array heterojunctions displayed not only rectifying behavior but also photovoltaic effects when illuminated with UV light. The low temperature and low cost of this fabrication process suggest that the selective growth of n-ZnO NRs on p-Si NR arrays might allow such structures to have diverse applications in optoelectronics.

19.
Biochem Biophys Res Commun ; 446(2): 580-4, 2014 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-24632201

RESUMO

The transcription factor forkhead box D3 (FOXD3) plays an important role in the development of neural crest and gastric cancer cells. However, the function and mechanisms of FOXD3 in the breast tumorigenesis and progression is still limited. Here, we report that FOXD3 is a tumor suppressor of breast cancer tumorigenicity and aggressiveness. We found that FOXD3 is down-regulated in breast cancer tissues. Patients with low FOXD3 expression have a poor outcome. Depletion of FOXD3 expression promotes breast cancer cell proliferation and invasion in vitro, whereas overexpression of FOXD3 inhibits breast cancer cell proliferation and invasion both in vitro and in vivo. In addition, depletion of FOXD3 is linked to epithelial-mesenchymal transition (EMT)-like phenotype. Our results indicate FOXD3 exhibits tumor suppressive activity and may be useful for breast therapy.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Transição Epitelial-Mesenquimal , Fatores de Transcrição Forkhead/deficiência , Fatores de Transcrição Forkhead/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Fatores de Transcrição Forkhead/genética , Humanos , Invasividade Neoplásica
20.
Eur J Nutr ; 53(2): 449-56, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23771791

RESUMO

PURPOSE: This study determined the effects of long-term D-galactose (DG) injection on the lung pro-inflammatory and fibrotic status and whether fructo-oligosaccharide (FO) could attenuate such effects. METHODS: Forty Balb/cJ mice (12 weeks of age) were divided into four groups: control (s.c. saline) (basal diet), DG (s.c. 1.2 g DG/kg body weight) (basal diet), DG + FO (FO diet, 2.5% w/w FO), and DG + E (vitamin E diet, α-tocopherol 0.2% w/w) serving as an antioxidant control group. These animals were killed after 49 day of treatments. Another group of naturally aging (NA) mice without any injection was killed at 64 weeks of age to be an aging control group. RESULTS: D-galactose treatment, generally similar to NA, increased the lung pro-inflammatory status, as shown in the IL-6 and IL-1ß levels and the expression of phospho-Jun and phospho-JNK, and the fibrotic status as shown in the hydroxyproline level compared to the vehicle. FO diminished the DG-induced increases in the lung IL-1ß level and expressions of total Jun, phospho-JNK, and attenuated DG effects on lung IL-6 and hydroxyproline, while α-tocopherol exerted anti-inflammatory effects on all parameters determined. FO, as well as α-tocopherol, modulated the large bowel ecology by increasing the fecal bifidobacteria and cecal butyrate levels compared with DG. CONCLUSIONS: D-galactose treatment mimicked the lung pro-inflammatory status as shown in the NA mice. FO attenuated the DG-induced lung pro-inflammatory status and down-regulated JNK/Jun pathway in the lung, which could be mediated by the prebiotic effects and metabolic products of FO in the large intestine.


Assuntos
Citocinas/biossíntese , Frutose/administração & dosagem , Galactose/administração & dosagem , Pulmão/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Oligossacarídeos/administração & dosagem , Animais , Antioxidantes/administração & dosagem , Ceco/química , Citocinas/análise , Citocinas/sangue , Ácidos Graxos Voláteis/análise , Fezes/microbiologia , Inflamação/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/análise , Pulmão/química , Pulmão/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Fosforilação , alfa-Tocoferol/administração & dosagem , Proteínas Quinases p38 Ativadas por Mitógeno/análise
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