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1.
IEEE Trans Cybern ; 53(9): 5826-5839, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35984806

RESUMO

Clinically, retinal vessel segmentation is a significant step in the diagnosis of fundus diseases. However, recent methods generally neglect the difference of semantic information between deep and shallow features, which fail to capture the global and local characterizations in fundus images simultaneously, resulting in the limited segmentation performance for fine vessels. In this article, a global transformer (GT) and dual local attention (DLA) network via deep-shallow hierarchical feature fusion (GT-DLA-dsHFF) are investigated to solve the above limitations. First, the GT is developed to integrate the global information in the retinal image, which effectively captures the long-distance dependence between pixels, alleviating the discontinuity of blood vessels in the segmentation results. Second, DLA, which is constructed using dilated convolutions with varied dilation rates, unsupervised edge detection, and squeeze-excitation block, is proposed to extract local vessel information, consolidating the edge details in the segmentation result. Finally, a novel deep-shallow hierarchical feature fusion (dsHFF) algorithm is studied to fuse the features in different scales in the deep learning framework, respectively, which can mitigate the attenuation of valid information in the process of feature fusion. We verified the GT-DLA-dsHFF on four typical fundus image datasets. The experimental results demonstrate our GT-DLA-dsHFF achieves superior performance against the current methods and detailed discussions verify the efficacy of the proposed three modules. Segmentation results of diseased images show the robustness of our proposed GT-DLA-dsHFF. Implementation codes will be available on https://github.com/YangLibuaa/GT-DLA-dsHFF.


Assuntos
Algoritmos , Vasos Retinianos , Vasos Retinianos/diagnóstico por imagem , Semântica , Processamento de Imagem Assistida por Computador
2.
ERJ Open Res ; 7(1)2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33532460

RESUMO

BACKGROUND: Probiotic treatments might contribute to the prevention of ventilator-associated pneumonia (VAP). Due to its unclear clinical effects, here we intend to assess the preventive effect and safety of probiotics on intensive care unit (ICU) patients. METHODS: Eligible randomised controlled trials were selected in databases until 30 September 2019. The characteristics of the studies were extracted, including study design, definition of VAP, probiotics intervention, category of included patients, incidence of VAP, mortality, duration of mechanical ventilation (MV) and ICU stay. Heterogeneity was evaluated by Chi-squared and I2 tests. RESULTS: 15 studies involving 2039 patients were identified for analysis. The pooled analysis suggests significant reduction on VAP (risk ratio, 0.68; 95% Cl, 0.60 to 0.77; p<0.00001) in a fixed-effects model. Subgroup analyses performed on the category of clinical and microbiological criteria both support the above conclusion; however, there were no significant differences in duration of MV or length of ICU stay in a random-effects model. Also, no significant differences in total mortality, overall mortality, 28-day mortality or 90-day mortality were found in the fixed-effects model. CONCLUSIONS: The probiotics helped to prevent VAP without impacting the duration of MV, length of ICU stay or mortality.

3.
Medicine (Baltimore) ; 98(25): e16145, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31232969

RESUMO

RATIONALE: Listeria monocytogenes rarely affects immunocompetent adults, and only a few cases of encephalitis caused by L monocytogenes in humans have been reported in China. PATIENT CONCERNS: A 37-year-old male patient presented with headache and fever of 38°C to 39°C for 2 days and dysphoria and dystrophy for 1 day. DIAGNOSIS: The patient was diagnosed as having encephalitis, and his cerebrospinal fluid (CSF) and blood cultures tested positive for L monocytogenes. INTERVENTIONS: The patient was treated with intravenous vancomycin, meropenem, mannitol, methylprednisolone, and enteral nutrition. The computed tomography (CT) scan showed swelling of the brain and hydrocephalus. The patient was treated with emergent surgery, a ventricular drainage tube was inserted, and the CSF was drained daily. OUTCOMES: Despite adequate therapy, the illness was severe and progressed rapidly. The patient died 2 weeks after admission. LESSONS: We report a rare case of L monocytogenes encephalitis in a previously healthy immunocompetent adult in China. The patient's CT scans showed increasing brain swelling and hydrocephalus, and the patient's condition progressively deteriorated.


Assuntos
Encefalite/diagnóstico , Listeriose/diagnóstico , Adulto , Antibacterianos/uso terapêutico , China , Diuréticos Osmóticos/uso terapêutico , Serviço Hospitalar de Emergência/organização & administração , Encefalite/diagnóstico por imagem , Encefalite/etiologia , Humanos , Listeria monocytogenes/patogenicidade , Listeriose/complicações , Listeriose/diagnóstico por imagem , Masculino , Manitol/uso terapêutico , Meropeném/uso terapêutico , Tomografia Computadorizada por Raios X/métodos , Vancomicina/uso terapêutico
4.
J Asthma ; 55(9): 956-965, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29211545

RESUMO

CONTEXT: Benralizumab is a humanized monoclonal antibody that targets the α chain of the IL-5 receptor (IL-5Rα) and is currently being assessed in clinical trials for asthma control. OBJECTIVE: Our systematic review and meta-analysis intends to evaluate the therapeutic efficacy and safety of benralizumab in patients with eosinophilic asthma. DATA SOURCES AND EXTRACTION: Literature searches of PubMed, Embase, and the Cochrane Library were performed to identify randomized controlled trials of benralizumab and clinic outcomes in asthmatics. RESULTS: In total, 7 articles with 2,321 subjects met our inclusion criteria. From this pooled analysis, we found that benralizumab significantly reduces exacerbations (RR: 0.63, 95% CI: 0.52-0.76, p < 0.00001; I2 = 52%, p = 0.06) compared to placebo in eosinophilic asthma. There was no statistical trend for improvement in forced expiratory volume in 1 second or asthma control indices such as Quality of Life Assessment (AQLQ) and Asthma Control Questionnaire score in benralizumab-treated patients. In addition, safety data indicated that benralizumab administration resulted no increasing incidence of adverse events and was well tolerated (RR: 1.00, 95% CI: 0.95-1.05, p = 0.96; I2 = 40%, p = 0.13). CONCLUSION: These results demonstrate the efficacy and safety of benralizumab for asthma patients with severe or uncontrolled symptoms and elevated eosinophils and provide support for benralizumab as an ideal option to treat asthma in this patient population.


Assuntos
Antiasmáticos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Asma/tratamento farmacológico , Eosinofilia/tratamento farmacológico , Eosinófilos , Asma/sangue , Asma/imunologia , Eosinofilia/sangue , Eosinofilia/imunologia , Humanos , Contagem de Leucócitos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
5.
Clinics (Sao Paulo) ; 72(9): 562-567, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29069260

RESUMO

OBJECTIVE: To investigate the value of high-flow nasal cannula oxygen therapy after extubation in patients with acute respiratory failure. METHODS: A single-center, prospective, randomized, controlled pilot trial was conducted between January 2013 and December 2014. Sixty enrolled patients were randomized immediately after extubation into either a high-flow nasal cannula group (n=30) or an air entrainment mask group (n=30) at a fixed inspired oxygen fraction (40%). The success rate of oxygen therapy, respiratory and hemodynamic parameters and subjective discomfort (using a visual analogue scale) were assessed at 24h after extubation. RESULTS: The two groups were comparable at extubation. A total of 46 patients were successfully treated including 27 patients in the high-flow nasal cannula group and 19 patients in the air entrainment mask group. Compared to the air entrainment mask group, the success rate of oxygen therapy and the partial pressure of arterial oxygen were significantly higher and the respiratory rate was lower in the high-flow nasal cannula group. In addition, less discomfort related to interface displacement and airway dryness was observed in the high-flow nasal cannula group than in the air entrainment mask group. CONCLUSIONS: At a fixed inspired oxygen fraction, the application of a high-flow nasal cannula after extubation achieves a higher success rate of oxygen therapy and less discomfort at 24h than an air entrainment mask in patients with acute respiratory failure.


Assuntos
Extubação/métodos , Cânula , Ventilação de Alta Frequência/métodos , Oxigenoterapia/métodos , Insuficiência Respiratória/terapia , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Feminino , Hemodinâmica , Ventilação de Alta Frequência/instrumentação , Humanos , Unidades de Terapia Intensiva , Masculino , Máscaras , Pessoa de Meia-Idade , Oxigênio/metabolismo , Oxigenoterapia/instrumentação , Projetos Piloto , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do Tratamento
6.
Clinics ; 72(9): 562-567, Sept. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-890728

RESUMO

OBJECTIVE: To investigate the value of high-flow nasal cannula oxygen therapy after extubation in patients with acute respiratory failure. METHODS: A single-center, prospective, randomized, controlled pilot trial was conducted between January 2013 and December 2014. Sixty enrolled patients were randomized immediately after extubation into either a high-flow nasal cannula group (n=30) or an air entrainment mask group (n=30) at a fixed inspired oxygen fraction (40%). The success rate of oxygen therapy, respiratory and hemodynamic parameters and subjective discomfort (using a visual analogue scale) were assessed at 24h after extubation. RESULTS: The two groups were comparable at extubation. A total of 46 patients were successfully treated including 27 patients in the high-flow nasal cannula group and 19 patients in the air entrainment mask group. Compared to the air entrainment mask group, the success rate of oxygen therapy and the partial pressure of arterial oxygen were significantly higher and the respiratory rate was lower in the high-flow nasal cannula group. In addition, less discomfort related to interface displacement and airway dryness was observed in the high-flow nasal cannula group than in the air entrainment mask group. CONCLUSIONS: At a fixed inspired oxygen fraction, the application of a high-flow nasal cannula after extubation achieves a higher success rate of oxygen therapy and less discomfort at 24h than an air entrainment mask in patients with acute respiratory failure.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Oxigenoterapia/métodos , Insuficiência Respiratória/terapia , Ventilação de Alta Frequência/métodos , Extubação/métodos , Cânula , Oxigênio/metabolismo , Oxigenoterapia/instrumentação , Fatores de Tempo , Ventilação de Alta Frequência/instrumentação , Projetos Piloto , Doença Aguda , Estudos Prospectivos , Reprodutibilidade dos Testes , Resultado do Tratamento , Desenho de Equipamento , Hemodinâmica , Unidades de Terapia Intensiva , Máscaras
7.
Inflammation ; 40(6): 2052-2061, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28812173

RESUMO

Neuroinflammatory response in spinal dorsal horn has been demonstrated to be a critical factor in oxaliplatin-induced pain. Melatonin has been shown to have anti-inflammatory and anti-allodynia effects in both preclinical and clinical studies. In the present study, we investigated the role of systemic administration of melatonin on oxaliplatin-induced pain. Intraperitoneal (i.p.) injection with oxaliplatin induced significantly mechanical allodynia and thermal hyperalgesia. Melatonin (i.p.) significantly alleviated mechanical allodynia and thermal hyperalgesia in the oxaliplatin but not sham-treated rats. The attenuation of nociceptive response persisted at least to 3 days after melatonin injection, throughout the entire observing window. Immunohistochemistry showed that oxaliplatin induced a significant increase of glial fibrillary acidic protein (GFAP) immunodensities, which could be suppressed by melatonin. Western blotting showed that GFAP protein levels were significantly elevated in the oxaliplatin-vehicle group. Melatonin significantly decreased oxaliplatin-induced upregulation of GFAP expressions. Oxaliplatin injection also enhanced the messenger RNA (mRNA) expressions of cytokines including interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) and chemokines including monocyte chemoattractant protein-1 (MCP-1) and monocyte inflammatory protein-1 (MIP-1α) in the spinal dorsal horn, which could be significantly repressed by melatonin. In vitro study showed that mRNA levels of TNF-α, IL-1ß, MCP-1, and MIP-1α in primarily astrocytes were significantly increased after lipopolysaccharide (LPS, 1 µg/ml) stimulation. Melatonin (10 and 100 µM) greatly inhibited synthesis of these inflammatory mediators, in a dose-related manner. Conclusively, our data provide a novel implication of anti-nociceptive mechanism of melatonin in chemotherapy-related pain.


Assuntos
Astrócitos/patologia , Inflamação/patologia , Melatonina/farmacologia , Medição da Dor/efeitos dos fármacos , Medula Espinal/patologia , Animais , Astrócitos/metabolismo , Mediadores da Inflamação/antagonistas & inibidores , Melatonina/uso terapêutico , Ratos
8.
Tumour Biol ; 35(2): 955-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23990443

RESUMO

Lung cancer is one of the most common cancers worldwide, but its etiology is still unclear. Superoxide dismutase 2 (SOD2) plays an essential role in oxidative stress and may be involved in the development of lung cancer. The association between SOD2 C47T polymorphism and lung cancer risk has been widely investigated, but the results of previous studies are contradictory. We conducted a meta-analysis to comprehensively assess the association between SOD2 C47T polymorphism and lung cancer. The association was estimated by odds ratio (OR) with 95 % confidence interval (95 % CI). A total of 10 studies with 5,146 cases and 6,173 controls were identified. The results showed that SOD2 C47T polymorphism was significantly associated with lung cancer (T versus C: OR = 0.88, 95 % CI = 0.83-0.93, P < 0.001; TT versus CC: OR = 0.74, 95 % CI = 0.66-0.83, P < 0.001; TT versus CC/CT: OR = 0.81, 95 % CI = 0.73-0.89, P < 0.001). Subgroup analysis by ethnicity suggested that SOD2 C47T polymorphism was significantly associated with lung cancer in both East Asians and Caucasians. Conclusively, this meta-analysis strongly suggests that SOD2 C47T polymorphism is significantly associated with lung cancer.


Assuntos
Estudos de Associação Genética , Neoplasias Pulmonares/genética , Superóxido Dismutase/genética , Povo Asiático/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/patologia , Polimorfismo de Nucleotídeo Único , Fatores de Risco , População Branca
9.
Asian Pac J Trop Med ; 6(12): 982-5, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24144032

RESUMO

OBJECTIVE: To explore effect of 5-AZn-2 '-deoxycytidine on proliferation of human lung adenocarcinoma cell line A549 in vitro. METHODS: Superoxide dismutase (SOD) activity was measured by hydroxylamine colorimetric method. Inhibition effect of 5-AZn-2' deoxycytidylic acid at different concentration and different time on growth of A549 cell was determined by MTT assay. Methylene dioxyamphetamine (MDA) was measured by thiobarbituric acid colorimetric method. Effect of 5-AZn-2' deoxycytidylic acid on apoptosis of A549 cell was determined by Hoechst 33258 dyeing detection. RESULTS: 5-AZn-2' deoxycytidylic acid had significant inhibition effect on proliferation of A549 cells in vitro, and the inhibition was notably dependent on time and dosage during 48-72 h; SOD level was significantly lower than those of control group (P<0.05, P<0.01), MDA level was significantly higher than those in the control group (P<0.05, P<0.01). A549 cells began to be in apoptosis after using 5-AZn-2'deoxycytidylic acid. CONCLUSIONS: 5- AZn-2' deoxycytidylic acid has significant inhibition effect on growth of A549 cell, and can lead the change of lipid peroxidation. It indicates that the mechanism has relationship with A549 cell cycle tissue and induction factor of apoptosis.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Proliferação de Células/efeitos dos fármacos , Adenocarcinoma , Adenocarcinoma de Pulmão , Apoptose/efeitos dos fármacos , Azacitidina/farmacologia , Linhagem Celular Tumoral , Forma Celular/efeitos dos fármacos , Decitabina , Humanos , Neoplasias Pulmonares , Malondialdeído/análise , Malondialdeído/metabolismo , Superóxido Dismutase/análise , Superóxido Dismutase/metabolismo
10.
CNS Neurosci Ther ; 19(5): 329-36, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23490331

RESUMO

BACKGROUND: Defining the impact of diabetes and related risk factors on brain cognitive function is critically important for patients with diabetes. AIMS: To investigate the alterations in hippocampal serine/threonine kinases signaling in the early phase of type 1 and type 2 diabetic rats. METHODS: Early experimental diabetes mellitus was induced in rats with streptozotocin or streptozotocin/high fat. Changes in the phosphorylation of proteins were determined by immunoblotting and immunohistochemistry. RESULTS: Our data showed a pronounced decrease in the phosphorylation of Ca(2+) /calmodulin-dependent protein kinase II (CaMKII) in the hippocampi of both type 1 and type 2 diabetic rats compared with age-matched control rats. Unexpectedly, we found a significant increase in the phosphorylation of synapsin I (Ser 603) and GluR1 (Ser 831) in the same experiment. In addition, aberrant changes in hippocampal protein kinase C (PKC) and protein kinase A (PKA) signaling in type 1 and type 2 diabetic rats were also found. Moreover, PP1α and PP2A protein levels were decreased in the hippocampus of type 1 diabetic rats, but significantly up-regulated in type 2 diabetic rats. CONCLUSIONS: The disturbance of CaMKII/PKA/PKC phosphorylation in the hippocampus is an early change that may be associated with the development and progression of diabetes-related cognitive dysfunction.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Diabetes Mellitus Experimental/metabolismo , Hipocampo/metabolismo , Proteína Quinase C/metabolismo , Animais , Masculino , Fosforilação , Proteína Fosfatase 1/análise , Proteína Fosfatase 2/análise , Ratos , Ratos Sprague-Dawley , Receptores de AMPA/metabolismo , Estreptozocina , Sinapsinas/metabolismo
11.
CNS Neurosci Ther ; 19(1): 53-60, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23171401

RESUMO

BACKGROUND: Tight junction protein degradation is a principal characteristic of the blood-brain barrier (BBB) damage that occurs during brain ischemia. AIMS: We investigated the mechanisms of occludin degradation that underlie permanent middle cerebral artery occlusion (pMCAO) in rats. METHODS AND RESULTS: Western blot and Co-immunoprecipitation data indicated ubiquitination and degradation of occludin in brain after pMCAO, which was consistent with ZO-1 degradation in penumbra regions as observed at 24 h after pMCAO. We further investigated candidate protease(s) responsible for the degradation of occludin during pMCAO. The intraventricular administration of γ-secretase blocker DAPT significantly inhibited the pMCAO-induced neurovascular damage, whereas ALLM and Batimastat, which are inhibitors of calpain and metalloproteinase proteases, respectively, were less effective. Notably, we found that DAPT significantly inhibited BBB disruption in comparison with vehicle treatment, as assessed by Evans blue excretion. Interestingly, the confocal immunostaining revealed that activation of the E3 ubiquitin ligase Itch is associated with degradation of occludin in brain microvessels following ischemia. Furthermore, our data demonstrate that the inhibition of γ-secretase signaling and the itch-mediated ubiquitination of occludin likely underlie the vasoprotective effect of DAPT after pMCAO. CONCLUSION: The γ-secretase blocker DAPT reduces the permeability of the BBB by decreasing the ubiquitination and degradation of occludin during permanent brain ischemia, suggesting that γ-secretase may represent a novel therapeutic target for preventing neurovascular damage.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Dipeptídeos/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Infarto da Artéria Cerebral Média , Ocludina/metabolismo , Ubiquitinação/efeitos dos fármacos , Secretases da Proteína Precursora do Amiloide/metabolismo , Análise de Variância , Animais , Modelos Animais de Doenças , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Imunoprecipitação , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Masculino , Permeabilidade/efeitos dos fármacos , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Ratos , Ratos Sprague-Dawley , Junções Íntimas/efeitos dos fármacos , Fatores de Tempo , Ubiquitina-Proteína Ligases/metabolismo , Proteína da Zônula de Oclusão-1/metabolismo
12.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 41(4): 402-9, 2012 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-22927075

RESUMO

OBJECTIVE: To investigate the effects of chronic lead exposure on expression of autophagy-associated proteins in rat hippocampus. METHODS: SD rats were randomly divided into three groups: control group was given distilled water, lead-exposed groups were given 0.5 g/L (low-dose) or 2.0 g/L(high-dose) lead acetate solution in drinking water. The rat pups started to drink the lead content water until 60 d maturity. The lead contents in blood and brain samples were analyzed by graphite furnace atomic absorption spectrophotometry. The expressions of Beclin 1, LC3, LAMP2 and cathepsin B proteins were detected by Western blot and immunohistochemistry. RESULTS: Compared with control group, the contents of lead were significantly higher in blood and hippocampus samples in chronic lead-exposed rats (P<0.01). Western blot showed that the expression of Beclin 1 and LC3-II/LC3-I increased significantly in high dose lead-exposed group compared with control group (P<0.05 or P<0.001). The confocal laser immunostaining results demonstrated that increased immunofluorescence staining of cathepsin B in hippocampal neurons compared with control animals. CONCLUSION: The disturbance of autophagy-lysosome signaling molecules might be partially contribute to neurotoxicity of chronic lead exposure.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Autofagia/fisiologia , Hipocampo/metabolismo , Intoxicação por Chumbo/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Animais , Autofagia/efeitos dos fármacos , Proteína Beclina-1 , Catepsina B/metabolismo , Doença Crônica , Modelos Animais de Doenças , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Intoxicação por Chumbo/patologia , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
13.
Exp Toxicol Pathol ; 64(6): 619-24, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21195594

RESUMO

The septal and temporal poles of the hippocampus differ markedly in their anatomical organization, but whether these distinct regions exhibit differential neurochemical profiles underlying lead (Pb(2+)) neurotoxicity remains to be determined. In the present study, we examined changes in the expression of Ca(2+)/calmodulin-dependent enzymes, including calpain, calcineurin, phospho-CaMKII (Thr286) and neuronal nitric oxide synthase (nNOS), in the rat dorsal and ventral hippocampus (DH and VH) after acute Pb(2+) exposure. Five days after Pb(2+) exposure, we observed constitutively active forms of calcineurin (45 kDa and 48 kDa) in ventral portions of the hippocampus, a result consistent with the observed calpain activation that is indicated by the breakdown of spectrin in this region. Our data demonstrate that nNOS expression is significantly higher in the ventral region of the hippocampus when compared to the dorsal region, whereas phosphorylation of CaMKII (Thr286) is less pronounced in the ventral portion of the hippocampus and more pronounced in dorsal regions after acute Pb(2+) exposure. Thus, it appears likely that the ventral region of hippocampus is more vulnerable to the neurotoxic effects of Pb(2+) than the dorsal region. Taken together, the present data suggest that acute lead exposure leads to differential expression patterns of Ca(2+)/calmodulin-dependent enzymes along the dorsoventral axis of the hippocampus.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Calpaína/metabolismo , Hipocampo/efeitos dos fármacos , Chumbo/toxicidade , Óxido Nítrico Sintase Tipo I/metabolismo , Transcriptoma/efeitos dos fármacos , Animais , Western Blotting , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/análise , Calpaína/análise , Hipocampo/metabolismo , Imuno-Histoquímica , Masculino , Óxido Nítrico Sintase Tipo I/análise , Ratos , Ratos Sprague-Dawley
14.
J Pineal Res ; 51(1): 124-35, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21392095

RESUMO

The cellular mechanisms that underlie the diverse nitrosative stress-mediated cellular events associated with ischemic complications in endothelial cells are not yet clear. To characterize whether autophagic elements are associated with the nitrosative stress that causes endothelial damage after ischemia injury, an in vitro sustained oxygen-glucose deprivation (OGD) and an in vivo microsphere embolism model were used in the present study. Consistent with OGD-induced peroxynitrite formation, a rapid induction of microtubule-associated protein 1 light chain 3 (LC3)-I/II conversion and green fluorescent protein-LC3 puncta accumulation were observed in endothelial cells. The Western blot analyses indicated that OGD induced elevations in lysosome-associated membrane protein 2 and cathepsin B protein levels. Similar results were observed in the microvessel insult model, following occlusion of the microvessels using microsphere injections in rats. Furthermore, cultured endothelial cells treated with peroxynitrite (1-50 µm) exhibited a concentration-dependent change in the pattern of autophagy-lysosome signaling. Intriguingly, OGD-induced autophagy-lysosome processes were attenuated by PEP-19 overexpression and by a small-interfering RNA (siRNA)-mediated knockdown of eNOS. The importance of nitrosative stress in ischemia-induced autophagy-lysosome cascades is further supported by our finding that pharmacological inhibition of nitrosative stress by melatonin partially inhibits the ischemia-induced autophagy-lysosome cascade and the degradation of the tight junction proteins. Taken together, the present results demonstrate that peroxynitrite-mediated nitrosative stress at least partially potentiates autophagy-lysosome signaling during sustained ischemic insult-induced endothelial cell damage.


Assuntos
Autofagia/fisiologia , Isquemia Encefálica/patologia , Lisossomos/metabolismo , Ácido Peroxinitroso/farmacologia , Animais , Autofagia/efeitos dos fármacos , Encéfalo/irrigação sanguínea , Isquemia Encefálica/metabolismo , Linhagem Celular , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Glucose/metabolismo , Humanos , Imuno-Histoquímica , Embolia Intracraniana , Masculino , Melatonina/farmacologia , Microscopia de Fluorescência , Microesferas , Microvasos , Proteínas do Tecido Nervoso/metabolismo , Nitrosação , Oxigênio/metabolismo , Ratos , Ratos Wistar , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/fisiologia
15.
J Pineal Res ; 50(3): 281-91, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21198825

RESUMO

Peroxynitrite contributes to diverse cellular stresses in the pathogenesis of ischemic complications. Here, we investigate the downstream effector signaling elements of nitrosative stress which regulate ischemia-like cell death in endothelial cells and protective effect of melatonin. When the mitochondrial membrane potential (ΔΨm) of oxygen-glucose deprivation (OGD)-treated cells was assessed using the fluorescent probe 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazol -carbocyanine iodide, we observed spontaneous changes in peroxynitrite formation. Concomitantly, western blot and confocal microscopy analyses indicated that prolonged OGD exposure initiates the release of mitochondrial HtrA2 and dramatically decreases phosphoprotein enriched in astrocytes (PED or PEA-15) protein levels. Consistently, cultured endothelial cells treated with peroxynitrite (1-50 µm) exhibited a concentration-dependent release of mitochondrial HtrA2 and concomitant PED degradation in vitro. Notably, HtrA2 activation coincided with increased nitrotyrosine immunoreactivity in microvessels of rats following microsphere embolism. Additionally, the protective effect of PED overexpression in OGD-induced apoptosis was abolished by transfection with the PED(S104A/S116A) mutant. Furthermore, the effect of melatonin, an potential antioxidant, on endothelial apoptotic cascade was examined in OGD-evoked nitrosative stress. Our data showed that the application of melatonin provided significant protection against OGD-induced peroxynitrite formation and mitochondrial HtrA2 release, accompanied with a decrease in degradation PED and x-linked inhibitor of apoptosis protein, which is associated with activation of the caspase cascade. Taken together, the protective effect of melatonin is likely mediated, in part, by inhibition of peroxynitrate-mediated nitrosative stress, which in turn relieves imbalance of mitochondrial HtrA2-PED signaling and endothelial cell death.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Células Endoteliais/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Fosfoproteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Serina Endopeptidases/metabolismo , Animais , Proteínas Reguladoras de Apoptose , Isquemia Encefálica/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Citometria de Fluxo , Serina Peptidase 2 de Requerimento de Alta Temperatura A , Humanos , Immunoblotting , Imunoprecipitação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Melatonina , Potencial da Membrana Mitocondrial , Microscopia Confocal , Proteínas Mitocondriais/genética , Proteínas do Tecido Nervoso/genética , Ácido Peroxinitroso/farmacologia , Fosfoproteínas/genética , Proteínas de Ligação a RNA/genética , Ratos , Ratos Wistar , Serina Endopeptidases/genética , Fatores de Processamento de Serina-Arginina , Transdução de Sinais/efeitos dos fármacos
16.
J Biol Chem ; 285(8): 5522-31, 2010 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-20018858

RESUMO

Different interacting signaling modules involving Ca(2+)/calmodulin-dependent myosin light chain kinase, Ca(2+)-independent regulatory light chain phosphorylation, myosin phosphatase inhibition, and actin filament-based proteins are proposed as specific cellular mechanisms involved in the regulation of smooth muscle contraction. However, the relative importance of specific modules is not well defined. By using tamoxifen-activated and smooth muscle-specific knock-out of myosin light chain kinase in mice, we analyzed its role in tonic airway smooth muscle contraction. Knock-out of the kinase in both tracheal and bronchial smooth muscle significantly reduced contraction and myosin phosphorylation responses to K(+)-depolarization and acetylcholine. Kinase-deficient mice lacked bronchial constrictions in normal and asthmatic airways, whereas the asthmatic inflammation response was not affected. These results indicate that myosin light chain kinase acts as a central participant in the contractile signaling module of tonic smooth muscle. Importantly, contractile airway smooth muscles are necessary for physiological and asthmatic airway resistance.


Assuntos
Brônquios/enzimologia , Contração Muscular/fisiologia , Tono Muscular/fisiologia , Músculo Liso/enzimologia , Quinase de Cadeia Leve de Miosina/metabolismo , Traqueia/enzimologia , Acetilcolina/metabolismo , Resistência das Vias Respiratórias/efeitos dos fármacos , Resistência das Vias Respiratórias/fisiologia , Animais , Antineoplásicos Hormonais/farmacologia , Asma/enzimologia , Asma/genética , Cálcio/metabolismo , Calmodulina/metabolismo , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Contração Muscular/efeitos dos fármacos , Tono Muscular/efeitos dos fármacos , Quinase de Cadeia Leve de Miosina/genética , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , Potássio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Tamoxifeno/farmacologia
17.
Am J Transl Res ; 1(3): 300-11, 2009 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-19956440

RESUMO

Human epithelial mucin, the major glycoprotein component of mucus, plays a critical role in host innate defense response against invading microbes by facilitating the mucociliary clearance. Excess mucin production, however, overwhelms the mucociliary clearance, resulting in not only defective mucosal defense but also conductive hearing loss in the middle ear and mucus obstruction in the airway. Indeed, mucus overproduction is a hall-mark of otitis media (OM) and chronic obstructive pulmonary diseases (COPD). Thus, tight regulation of mucin production plays an important role in maintaining an appropriate balance between beneficial and detrimental outcomes. We previously reported that Streptococcus pneumoniae (S. pneumoniae) up-regulates MUC5AC mucin expression via a positive MAPK ERK1/2 and a negative JNK1/2 signaling pathway. However, the signaling components including the up-stream activators and the down-stream transcription factors involved in these two path-ways remain largely unknown. In the present study, we showed that positive regulation of MUC5AC mucin expression by ERK1/2 is dependent on Ras-Raf-1 signaling pathway, whereas the negative regulation of MUC5AC expression by JNK1/2 is dependent on MEKK3. Moreover, transcriptional factor AP-1 acts as a key regulator for both of the positive and negative regulation of MUC5AC mucin expression as evidenced by mutagenesis analysis of two AP-1 sites in the promoter region of human MUC5AC mucin gene. Ras-Raf1-ERK1/2-dependent AP-1 activation positively regulates MUC5AC mucin induction by S. pneumoniae, whereas MEKK3-JNK1/2-dependent AP-1 activation negatively regulates it. Therefore, our data unveiled a novel signaling mechanism underlying the tight regulation of MUC5AC mucin induction by S. pneumoniae and may lead to the development of new therapeutic strategy for reducing mucus overproduction in both OM and COPD.

18.
Zhonghua Jie He He Hu Xi Za Zhi ; 32(4): 270-3, 2009 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-19576040

RESUMO

OBJECTIVE: To evaluate the basic knowledge of asthma, the standardization of treatment and the continuing education with community physicians in Hangzhou. METHODS: The survey investigated a total of 45 community health service centers in Hangzhou, and 2 - 4 western medicine physicians were randomly selected from each centre. A questionnaire was completed by totally 114 doctors under investigation. RESULTS: Eighty-seven percent of the physicians believed asthma was an airway inflammatory disease. Sixty-nine percent chose inhaled glucocorticoids as daily first-line drug for persistent asthma and 55% had read asthma guidelines. However, only 24% had ever heard China Asthma Alliance (CAA) and only 6% had visited its website. Moreover, no one under investigation had participated in the CAA organized talks popularizing the standardization of asthma treatment. Over the past year, 55% of the respondents did not participate in any asthma-related meetings or seminars. Ninety-six percent of those surveyed expressed the hope that higher-level hospital doctors would come to the community hospital for asthma-related seminars. Among the 45 community health service centers, only 2 collected part of the registration data for asthma patients and only one conducted health education seminars for asthma patients during the past year. CONCLUSION: Community physicians need to be provided more continuing education opportunities in order for them to provide standard asthma treatment for patients.


Assuntos
Asma/terapia , Serviços de Saúde Comunitária , Conhecimentos, Atitudes e Prática em Saúde , China , Humanos , Médicos , Inquéritos e Questionários
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