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1.
Opt Express ; 32(10): 17738-17762, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38858948

RESUMO

Multi-directional polarized optical sensors are increasingly vital in passive remote sensing, deepening our understanding of global cloud properties. Nevertheless, uncertainty lingers on how these observations can contribute to our knowledge of cloud diversity. The variability in cloud PSD (Particle Size Distribution) significantly influences a wide array of cloud characteristics, while unidentified factors in RT (Radiative Transfer) may introduce errors into the cloud PSD retrieval algorithm. Therefore, establishing unified evaluation criteria for both optical device configuration and inversion methods is crucial. Our study, based on Bayesian theory and RT, assesses the information content of both cloud effective radius and effective variance retrieval, along with the key factors affecting their retrieval in multi-directional polarized observations, using the calculation of DFS (Degree of Freedom for Signals).We consider the process of solar incidence, cloud scattering, and sensor reception, and discuss the impact of various sensor configurations, cloud characteristics, and other components on the retrieval of cloud PSD. Correspondingly, we observed a 48% improvement in the information content of cloud PSD with the incorporation of multi-directional polarized measurements in the rainbow region. Cloud droplet concentration significantly influences inversion, but its PSD does not cause monotonic linear interference on information content. The blending of particle mixtures with different PSD has a significant negative impact on DFS. In cases where the AOD (Aerosol Optical Depth) is less than 0.5 and the COT (Cloud Optical Thickness) exceeds 5, the influence of aerosol and surface contributions on inversion can be neglected. Our findings would serve as a foundation for future instrument design improvements and enhancements to retrieval algorithms.

3.
Interact J Med Res ; 13: e43585, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38526532

RESUMO

BACKGROUND: The novel coronavirus SARS-CoV-2 caused the global COVID-19 pandemic. Emerging reports support lower mortality and reduced case numbers in highland areas; however, comparative studies on the cumulative impact of environmental factors and viral genetic diversity on COVID-19 infection rates have not been performed to date. OBJECTIVE: The aims of this study were to determine the difference in COVID-19 infection rates between high and low altitudes, and to explore whether the difference in the pandemic trend in the high-altitude region of China compared to that of the lowlands is influenced by environmental factors, population density, and biological mechanisms. METHODS: We examined the correlation between population density and COVID-19 cases through linear regression. A zero-shot model was applied to identify possible factors correlated to COVID-19 infection. We further analyzed the correlation of meteorological and air quality factors with infection cases using the Spearman correlation coefficient. Mixed-effects multiple linear regression was applied to evaluate the associations between selected factors and COVID-19 cases adjusting for covariates. Lastly, the relationship between environmental factors and mutation frequency was evaluated using the same correlation techniques mentioned above. RESULTS: Among the 24,826 confirmed COVID-19 cases reported from 40 cities in China from January 23, 2020, to July 7, 2022, 98.4% (n=24,430) were found in the lowlands. Population density was positively correlated with COVID-19 cases in all regions (ρ=0.641, P=.003). In high-altitude areas, the number of COVID-19 cases was negatively associated with temperature, sunlight hours, and UV index (P=.003, P=.001, and P=.009, respectively) and was positively associated with wind speed (ρ=0.388, P<.001), whereas no correlation was found between meteorological factors and COVID-19 cases in the lowlands. After controlling for covariates, the mixed-effects model also showed positive associations of fine particulate matter (PM2.5) and carbon monoxide (CO) with COVID-19 cases (P=.002 and P<.001, respectively). Sequence variant analysis showed lower genetic diversity among nucleotides for each SARS-CoV-2 genome (P<.001) and three open reading frames (P<.001) in high altitudes compared to 300 sequences analyzed from low altitudes. Moreover, the frequencies of 44 nonsynonymous mutations and 32 synonymous mutations were significantly different between the high- and low-altitude groups (P<.001, mutation frequency>0.1). Key nonsynonymous mutations showed positive correlations with altitude, wind speed, and air pressure and showed negative correlations with temperature, UV index, and sunlight hours. CONCLUSIONS: By comparison with the lowlands, the number of confirmed COVID-19 cases was substantially lower in high-altitude regions of China, and the population density, temperature, sunlight hours, UV index, wind speed, PM2.5, and CO influenced the cumulative pandemic trend in the highlands. The identified influence of environmental factors on SARS-CoV-2 sequence variants adds knowledge of the impact of altitude on COVID-19 infection, offering novel suggestions for preventive intervention.

4.
J Med Internet Res ; 25: e48115, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37632414

RESUMO

BACKGROUND: Biomedical relation extraction (RE) is of great importance for researchers to conduct systematic biomedical studies. It not only helps knowledge mining, such as knowledge graphs and novel knowledge discovery, but also promotes translational applications, such as clinical diagnosis, decision-making, and precision medicine. However, the relations between biomedical entities are complex and diverse, and comprehensive biomedical RE is not yet well established. OBJECTIVE: We aimed to investigate and improve large-scale RE with diverse relation types and conduct usability studies with application scenarios to optimize biomedical text mining. METHODS: Data sets containing 125 relation types with different entity semantic levels were constructed to evaluate the impact of entity semantic information on RE, and performance analysis was conducted on different model architectures and domain models. This study also proposed a continued pretraining strategy and integrated models with scripts into a tool. Furthermore, this study applied RE to the COVID-19 corpus with article topics and application scenarios of clinical interest to assess and demonstrate its biological interpretability and usability. RESULTS: The performance analysis revealed that RE achieves the best performance when the detailed semantic type is provided. For a single model, PubMedBERT with continued pretraining performed the best, with an F1-score of 0.8998. Usability studies on COVID-19 demonstrated the interpretability and usability of RE, and a relation graph database was constructed, which was used to reveal existing and novel drug paths with edge explanations. The models (including pretrained and fine-tuned models), integrated tool (Docker), and generated data (including the COVID-19 relation graph database and drug paths) have been made publicly available to the biomedical text mining community and clinical researchers. CONCLUSIONS: This study provided a comprehensive analysis of RE with diverse relation types. Optimized RE models and tools for diverse relation types were developed, which can be widely used in biomedical text mining. Our usability studies provided a proof-of-concept demonstration of how large-scale RE can be leveraged to facilitate novel research.


Assuntos
COVID-19 , Humanos , Mineração de Dados , Bases de Dados Factuais , Conhecimento , Medicina de Precisão
5.
iScience ; 26(4): 106356, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37091235

RESUMO

Functional explication of genes is of great scientific value. However, conventional methods have challenges for those genes that may affect biological processes but are not annotated in public databases. Here, we developed a novel explainable gene ontology fingerprint (XGOF) method to automatically produce knowledge networks on biomedical literature in a given field which quantitatively characterizes the association between genes and ontologies. XGOF provides systematic knowledge for the potential function of genes and ontologically compares similarities and discrepancies in different disease-XGOFs integrating omics data. More importantly, XGOF can not only help to infer major cellular components in a disease microenvironment but also reveal novel gene panels or functions for in-depth experimental research where few explicit connections to diseases have previously been described in the literature. The reliability of XGOF is validated in four application scenarios, indicating a unique perspective of integrating text and data mining, with the potential to accelerate scientific discovery.

6.
Bioinformatics ; 39(1)2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36342236

RESUMO

MOTIVATION: Virus mutation is one of the most important research issues which plays a critical role in disease progression and has prompted substantial scientific publications. Mutation extraction from published literature has become an increasingly important task, benefiting many downstream applications such as vaccine design and drug usage. However, most existing approaches have low performances in extracting virus mutation due to both lack of precise virus mutation information and their development based on human gene mutations. RESULTS: We developed ViMRT, a text-mining tool and search engine for automated virus mutation recognition using natural language processing. ViMRT mainly developed 8 optimized rules and 12 regular expressions based on a development dataset comprising 830 papers of 5 human severe disease-related viruses. It achieved higher performance than other tools in a test dataset (1662 papers, 99.17% in F1-score) and has been applied well to two other viruses, influenza virus and severe acute respiratory syndrome coronavirus-2 (212 papers, 96.99% in F1-score). These results indicate that ViMRT is a high-performance method for the extraction of virus mutation from the biomedical literature. Besides, we present a search engine for researchers to quickly find and accurately search virus mutation-related information including virus genes and related diseases. AVAILABILITY AND IMPLEMENTATION: ViMRT software is freely available at http://bmtongji.cn:1225/mutation/index.


Assuntos
Mineração de Dados , Vírus , Mineração de Dados/métodos , Mutação , Ferramenta de Busca , Vírus/genética
7.
Comput Math Methods Med ; 2022: 5002681, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35936364

RESUMO

The risk factors of upper respiratory tract infection (URI) within 6 months after diagnosis in patients with idiopathic thrombocytopenic purpura (ITP) were analyzed, and the nomogram model was established and verified, with 242 and 50 ITP patients as the training and validation set, respectively. The patients were followed up for six months after the diagnosis of ITP. The clinical data of patients were collected, and the risk factors of URI in ITP patients within six months after diagnosis were analyzed using univariable, followed by multivariable logistic regression. Among the 242 ITP patients in the training set, 52 cases (21.49%) had URI, including 24 cases of viral infection, 11 cases of Mycoplasma pneumoniae infection, and 17 cases of bacterial infection. Logistic regression analysis showed that advanced age, use of glucocorticoid, smoking history, platelet count, serum CRP level, and lymphocyte subsets CD4 + and CD8 + were all risk factors for ITP patients to develop symptoms within six months after diagnosis (P < 0.05). Using the above five indicators, a nomogram prediction model was built for URI occurrence in patients with ITP within half a year after diagnosis, and the results showed an AUC, a sensitivity, and a specificity of 0.936 (95% CI: 0.878-0.983), 0.942, and 0.865, respectively. The nomogram model was internally verified by the bootstrap method for 500 self-sampling times, and the prediction of the calibration curve was in high consistency with the real results. External validation of the nomogram model resulted in an AUC, a sensitivity, and a specificity of 0.890 (95% CI: 0.757-0.975), 0.949, and 0.727, respectively. The nomogram model of URI in ITP patients within half a year after diagnosis based on logistic regression analysis has good discrimination and prediction accuracy. This provides important guidance value for individualized prediction of URI in ITP patients.


Assuntos
Púrpura Trombocitopênica Idiopática , Infecções Respiratórias , Humanos , Lactente , Nomogramas , Contagem de Plaquetas , Púrpura Trombocitopênica Idiopática/diagnóstico , Infecções Respiratórias/diagnóstico , Estudos Retrospectivos
10.
Nucleic Acids Res ; 50(D1): D918-D927, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34500462

RESUMO

Molecular mechanisms of virus-related diseases involve multiple factors, including viral mutation accumulation and integration of a viral genome into the host DNA. With increasing attention being paid to virus-mediated pathogenesis and the development of many useful technologies to identify virus mutations (VMs) and viral integration sites (VISs), much research on these topics is available in PubMed. However, knowledge of VMs and VISs is widely scattered in numerous published papers which lack standardization, integration and curation. To address these challenges, we built a pilot database of human disease-related Virus Mutations, Integration sites and Cis-effects (ViMIC), which specializes in three features: virus mutation sites, viral integration sites and target genes. In total, the ViMIC provides information on 31 712 VMs entries, 105 624 VISs, 16 310 viral target genes and 1 110 015 virus sequences of eight viruses in 77 human diseases obtained from the public domain. Furthermore, in ViMIC users are allowed to explore the cis-effects of virus-host interactions by surveying 78 histone modifications, binding of 1358 transcription regulators and chromatin accessibility on these VISs. We believe ViMIC will become a valuable resource for the virus research community. The database is available at http://bmtongji.cn/ViMIC/index.php.


Assuntos
Bases de Dados Factuais , Genoma Viral , Interações Hospedeiro-Patógeno/genética , Software , Proteínas Virais/genética , Viroses/genética , Vírus/genética , Cromatina/química , Cromatina/metabolismo , Mineração de Dados , Regulação da Expressão Gênica , Histonas/genética , Histonas/metabolismo , Humanos , Internet , Mutação , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Virais/metabolismo , Viroses/metabolismo , Viroses/patologia , Viroses/virologia , Integração Viral/genética , Vírus/metabolismo , Vírus/patogenicidade
11.
Cancer Manag Res ; 13: 7981-7988, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707404

RESUMO

OBJECTIVE: This review aims to clarify the necessity of hepatic hilar lymph node resection on advanced ovarian cancer patients. BACKGROUND: PARP inhibitors and surgery have significantly improved the survival of patients with ovarian cancer. However, for patients with advanced ovarian cancer, there are often extensive epigastric disseminated metastatic lesions, especially the lymph nodes in the hepatic hilar area. Because of the complicated anatomical relationship and lack of experience in this area, this is easily ignored by gynecological oncologists. METHODS: Through the retrieval and analysis of the current database, namely PubMed, Medline, Web of Science, EMBASE, Cochrane Library, and Wangfang, etc., the literature regarding this topic published before March 2021 were thoroughly investigated. CONCLUSION: For the hepatic hilar regional lymph node surgery, through careful preoperative evaluation, surgical-indication clarification, appropriate case selection, standardized surgical operations and multidisciplinary cooperation with general surgeons, the prognosis of patients is significantly improved. Postoperative complications are also safe and controllable and convincing. To conclude, the application of hilar region lymph node cytoreductive surgery for patients with advanced ovarian cancer is a feasible and preferred choice.

12.
PM R ; 8(7): 651-9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26968608

RESUMO

BACKGROUND: Respiratory complications are major causes of morbidity and mortality in persons with a spinal cord injury, partly because of respiratory muscle paralysis. Earlier investigation has demonstrated that functional magnetic stimulation (FMS) can be used as a noninvasive technology for activating expiratory muscles, thus producing useful expiratory functions (simulated cough) in subjects with spinal cord injury. OBJECTIVE: To evaluate the effectiveness of FMS for conditioning inspiratory and expiratory muscles in persons with tetraplegia. DESIGN: A prospective before and after trial. SETTING: FMS Laboratory, Louis Stokes Cleveland VA Medical Center, Cleveland, OH. PARTICIPANTS: Six persons with tetraplegia. METHOD: Each subject participated in a 6-week FMS protocol for conditioning the inspiratory and expiratory muscles. A magnetic stimulator was used with the center of a magnetic coil placed at the C7-T1 and T9-T10 spinous processes, respectively. Pulmonary function tests were performed before, during, and after the protocol. MAIN OUTCOME MEASUREMENTS: Respiratory variables included maximal inspiratory pressure (MIP), inspiratory reserve volume (IRV), peak inspiratory flow (PIF), maximal expiratory pressure (MEP), expiratory reserve volume (ERV), and peak expiratory flow (PEF). RESULTS: After 6 weeks of conditioning, the main outcome measurements (mean ± standard error) were as follows: MIP, 89.6 ± 7.3 cm H2O; IRV, 1.90 ± 0.34 L; PIF, 302.4 ± 36.3 L/min; MEP, 67.4 ± 11.1 cm H2O; ERV, 0.40 ± 0.06 L; and PEF, 372.4 ± 31.9 L/min. These values corresponded to 117%, 107%, 136%, 109%, 130%, and 124% of pre-FMS conditioning values, respectively. Significant improvements were observed in MIP (P = .022), PIF (P = .0001), and PEF (P = .0006), respectively. When FMS was discontinued for 4 weeks, these values showed decreases from their values at the end of the conditioning protocol, which suggests that continual FMS may be necessary to maintain improved respiratory functions. CONCLUSION: FMS conditioning of the inspiratory and expiratory muscles improved voluntary inspiratory and expiratory functions. FMS may be a noninvasive technology for respiratory muscle training in persons with tetraplegia.


Assuntos
Quadriplegia , Humanos , Estudos Prospectivos , Músculos Respiratórios , Paralisia Respiratória , Traumatismos da Medula Espinal
13.
Cancer Res ; 71(13): 4494-505, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21555370

RESUMO

Targeted therapies for cancer are inherently limited by the inevitable recurrence of resistant disease after initial responses. To define early molecular changes within residual tumor cells that persist after treatment, we analyzed drug-sensitive lung adenocarcinoma cell lines exposed to reversible or irreversible epidermal growth factor receptor (EGFR) inhibitors, alone or in combination with MET-kinase inhibitors, to characterize the adaptive response that engenders drug resistance. Tumor cells displaying early resistance exhibited dependence on MET-independent activation of BCL-2/BCL-XL survival signaling. Further, such cells displayed a quiescence-like state associated with greatly retarded cell proliferation and cytoskeletal functions that were readily reversed after withdrawal of targeted inhibitors. Findings were validated in a xenograft model, showing BCL-2 induction and p-STAT3[Y705] activation within the residual tumor cells surviving the initial antitumor response to targeted therapies. Disrupting the mitochondrial BCL-2/BCL-XL antiapoptotic machinery in early survivor cells using BCL-2 Homology Domain 3 (BH3) mimetic agents such as ABT-737, or by dual RNAi-mediated knockdown of BCL-2/BCL-XL, was sufficient to eradicate the early-resistant lung-tumor-cells evading targeted inhibitors. Similarly, in a xenograft model the preemptive cotreatment of lung tumor cells with an EGFR inhibitor and a BH3 mimetic eradicated early TKI-resistant evaders and ultimately achieved a more durable response with prolonged remission. Our findings prompt prospective clinical investigations using BH3-mimetics combined with targeted receptor kinase inhibitors to optimize and improve clinical outcomes in lung-cancer treatment.


Assuntos
Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/enzimologia , Receptores ErbB/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/enzimologia , Inibidores de Proteínas Quinases/farmacologia , Adenocarcinoma de Pulmão , Animais , Compostos de Bifenilo/farmacologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Cloridrato de Erlotinib , Humanos , Indóis/farmacologia , Camundongos , Nitrofenóis/farmacologia , Fragmentos de Peptídeos/metabolismo , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Quinazolinas/farmacologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Sulfonamidas/farmacologia , Transplante Heterólogo , Proteína bcl-X/metabolismo
14.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(1): 272-6, 2011 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-21428104

RESUMO

Multispectral area CCD camera based on liquid crystal tunable filter (LCTF) is a new spectral imaging system, which could record image of one wavelength on the area CCD by utilizing electrically controlled birefringence of liquid-crystal and interference principle of polarized light. Because of the special working principle of LCTF and frame transfer area CCD, the existing radiometric calibration method can not meet the precision need of remote sensing application if it is used for LCTF-camera. An improved radiometric calibration method is proposed, in which the camera performance test and calibration experiment are carried out relying on the devices of integrating sphere and standard detector, and the absolute calibration coefficient is calculated via correcting frame transfer smear and improving data process algorithm. Then the validity of the laboratory calibration coefficient is checked by a field validation experiment. Experimental result indicates that the calibration coefficient is valid, and the radiation information on the ground could be accurately inverted from the calibrated image data. With the resolution of radiometric calibration of LCTF-camera and the improvement of calibration precision, the application field of the image data acquired by the camera would be extended effectively.

15.
J Biol Chem ; 283(40): 26850-8, 2008 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-18678874

RESUMO

Adiponectin is an adipokine with potent anti-inflammatory properties. Treatment of macrophages with adiponectin results in a suppression of lipopolysaccharide (LPS)-stimulated cytokine production. Here we investigated the transcriptional and post-transcriptional mechanisms by which adiponectin suppresses LPS-stimulated tumor necrosis factor (TNF)-alpha production. Treatment of RAW 264.7 macrophages with LPS increased TNF-alpha promoter-driven luciferase activity (TNF-alpha promoter/Luc activity) by 20-fold over basal. After culture with 1 mug/ml globular adiponectin (gAcrp) for 18 h, TNF-alpha promoter/Luc activity was increased even in the absence of LPS; further challenge with LPS only increased TNF-alpha promoter/Luc activity by 1.4-fold. Treatment with gAcrp decreased LPS-stimulated ERK1/2 phosphorylation and IkappaB degradation and suppressed the ability of LPS to increase the DNA binding activity of Egr-1 and p65. gAcrp also suppressed LPS-mediated stabilization of TNF-alpha mRNA. In controls cells, the half-life of TNF-alpha mRNA was increased from approximately 30 min at base line to approximately 80 min in response to LPS. After treatment with gAcrp for 18 h, LPS failed to increase TNF-alpha mRNA stability. This gAcrp-mediated loss of stimulus-induced stabilization of TNF-alpha mRNA required the presence of the TNF-alpha 3'-untranslated region and was associated with an increase in expression and RNA binding activity of tristetraprolin, an mRNA-binding protein that destabilizes TNF-alpha mRNA. In summary, these data characterize the complex transcriptional and post-transcriptional effects of gAcrp on LPS-stimulated TNF-alpha expression in macrophages. gAcrp treatment profoundly suppressed the ability of LPS to increase TNF-alpha transcription and reduced the stimulus-induced stabilization of TNF-alpha mRNA in response to LPS.


Assuntos
Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Estabilidade de RNA/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Fator de Necrose Tumoral alfa/biossíntese , Adiponectina/farmacologia , Animais , Linhagem Celular , Humanos , Proteínas I-kappa B/metabolismo , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Regiões Promotoras Genéticas , Fatores de Tempo , Tristetraprolina/biossíntese
16.
J Cell Physiol ; 217(3): 652-66, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18651635

RESUMO

Bone loss that causes aseptic loosening of orthopedic implants is initiated by pro-inflammatory cytokines produced by macrophages in response to implant-derived wear particles. MAPK and NF-kappaB signaling pathways are activated by the particles; however, it is not clear which of the signaling pathways are important for the initial response to the wear particles and which are only involved at later steps in the process, such as osteoclast differentiation. Here, we show that the ERK1/2, p38, JNK, and NF-kappaB pathways are rapidly activated by the wear particles but that only the ERK1/2 and NF-kappaB pathways are required for the initial response to the wear particles, which include increases in TNFalpha promoter activity, TNFalpha mRNA expression, and secretion of TNFalpha protein. Moreover, ERK1/2 activation by wear particles is also required for increased expression of the transcription factor Egr-1 as well as Egr-1's ability to bind to and activate the TNFalpha promoter. These results, together with our previous studies of the PI3K/Akt pathway, demonstrate that wear particles coordinately activate multiple signaling pathways and multiple transcription factors to stimulate production of pro-inflammatory cytokines, such as TNFalpha. The current study also demonstrates that the signaling pathways are activated to a much greater extent by wear particles with adherent endotoxin than by "endotoxin-free" wear particles. These results, together with those demonstrating the requirement for ERK1/2/Egr-1 and NF-kappaB, show that activation of these signaling pathways is responsible for the ability of adherent endotoxin to potentiate cytokine production, osteoclast differentiation, and bone loss induced by wear particles.


Assuntos
Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Macrófagos/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , NF-kappa B/metabolismo , Titânio/farmacologia , Fator de Necrose Tumoral alfa/biossíntese , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Endotoxinas/farmacologia , Ativação Enzimática/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Lipopolissacarídeos/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Próteses e Implantes , Proteínas Proto-Oncogênicas c-jun/metabolismo , Solubilidade/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
17.
J Gastroenterol Hepatol ; 23 Suppl 1: S50-3, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18336664

RESUMO

Adiponectin is an adipokine with potent anti-inflammatory properties. The development of alcoholic liver disease is thought to involve increased pro-inflammatory activity, mediated in part by the activation of hepatic macrophages (Kupffer cells). Chronic ethanol feeding sensitizes hepatic macrophages to activation by lipopolysaccharide (LPS), leading to increased production of reactive oxygen species and tumor necrosis factor-alpha (TNF-alpha). Adiponectin can normalize Toll-like receptor-4 (TLR-4) mediated signaling in hepatic macrophages after ethanol feeding, likely contributing to the hepatoprotective effect of adiponectin in the progression of alcoholic liver disease. However, the mechanisms by which adiponectin suppress TLR-4 mediated responses are not well understood. Using the macrophage-like cell line, RAW264.7, we have investigated the molecular mechanisms by which adiponectin suppresses LPS-stimulated TNF-alpha production. Globular adiponectin (gAcrp)-mediated desensitization of LPS-stimulated responses in RAW264.7 macrophages was dependent on the production of the anti-inflammatory cytokine interleukin (IL)-10. gAcrp initially increased TNF-alpha expression in RAW264.7 macrophages; this TNF-alpha then contributed to increased expression of IL-10. This initial gAcrp-mediated increase in TNF-alpha production by macrophages was mediated via activation of ERK1/2-->Egr-1 and nuclear factor (NF)-kappaB-dependent mechanisms. gAcrp-stimulated IL-10 expression was also dependent on the phosphorylation of cAMP response element-binding protein and the cAMP response element in the IL-10 promoter. In summary, these studies reveal a complex, integrated response of macrophages to gAcrp. gAcrp initially activated signaling pathways considered to be pro-inflammatory, with a subsequent increase in the expression of the potent, anti-inflammatory cytokine, IL-10. Increased IL-10 expression was ultimately required for the suppression of TLR4-mediated signaling by gAcrp.


Assuntos
Adiponectina/fisiologia , Macrófagos/fisiologia , Fator de Necrose Tumoral alfa/biossíntese , Animais , Etanol/farmacologia , Interleucina-10/biossíntese , Macrófagos/efeitos dos fármacos
18.
J Leukoc Biol ; 83(5): 1258-66, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18263767

RESUMO

Adiponectin, an adipokine predominantly secreted from adipose tissue, has potent anti-inflammatory properties. Although the mechanisms for the anti-inflammatory properties of adiponectin are not well understood, recent evidence suggests that increased production of interleukin-10 (IL-10), a potent immunomodulatory cytokine, is involved in the anti-inflammatory actions of adiponectin. Globular adiponectin (gAcrp) increased IL-10 promoter activity and IL-10 mRNA accumulation in RAW 264.7 macrophages. Deletion of the sequences from -416 and -369 in the IL-10 promoter, containing a cyclic AMP-response element (CRE), decreased gAcrp-induced IL-10 promoter activation. Treatment of RAW 264.7 macrophages with gAcrp increased the phosphorylation of cyclic AMP response element binding protein (CREB) at Ser(133), as well as enhanced the DNA binding activity of CREB. Further, overexpression of a dominant negative form of CREB suppressed gAcrp-induced transcriptional activation of IL-10. gAcrp-stimulated CREB phosphorylation was mediated by the activation of both ERK1/2- and cAMP-dependent protein kinase (PKA)-dependent pathways. Inhibition of either ERK1/2 or PKA activity prevented gAcrp-stimulated CREB phosphorylation, as well as gAcrp-stimulated IL-10 promoter activation. Taken together, these data identify gAcrp-stimulated phospho-CREB as a key transcription factor responsible for gAcrp-induced IL-10 promoter activation.


Assuntos
Adiponectina/farmacologia , Proteína de Ligação a CREB/fisiologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/fisiologia , Interleucina-10/genética , Animais , Linhagem Celular , Luciferases/genética , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Camundongos , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ativação Transcricional/efeitos dos fármacos , Transfecção
19.
J Biol Chem ; 282(30): 21695-703, 2007 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-17537727

RESUMO

Adiponectin is an adipokine with potent anti-inflammatory properties. However, the mechanisms by which adiponectin suppresses macrophage function are not well understood. Treatment of RAW264.7 macrophages with adiponectin for 18 h decreased lipopolysaccharide (LPS)-stimulated tumor necrosis factor-alpha (TNF-alpha) production. Here we demonstrate that globular adiponectin (gAcrp) initially increased TNF-alpha expression in RAW264.7 macrophages; this TNF-alpha then contributed to increased expression of interleukin-10, which in turn was required for the development of tolerance to subsequent LPS exposure. gAcrp-mediated increases in TNF-alpha mRNA accumulation were associated with increased TNF-alpha promoter activity. gAcrp increased the DNA binding activity of both Egr-1 and NFkappaB; mutation of either the Egr-1 or NFkappaB binding sites in the TNF-alpha promoter decreased gAcrp-stimulated promoter activity. Further, co-transfection with either dominant negative Egr-1 or the IkappaB super-repressor prevented gAcrp-stimulated TNF-alpha promoter activity. gAcrp also increased Egr-1 promoter activity, mRNA accumulation, and DNA binding activity. Inhibition of ERK1/2 with U0126 potently suppressed gAcrp-stimulated Egr-1 promoter activity, as well as TNF-alpha promoter activity. In summary, these data demonstrate that adiponectin initially increases TNF-alpha production by macrophages via ERK1/2-->Egr-1 and NFkappaB-dependent mechanisms; these increases in TNF-alpha in turn lead to increased expression of interleukin-10 and an eventual dampening of LPS-mediated cytokine production in macrophages.


Assuntos
Adiponectina/farmacologia , Proteína 1 de Resposta de Crescimento Precoce/genética , Interleucina-10/biossíntese , Macrófagos/fisiologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fator de Necrose Tumoral alfa/genética , Animais , Linhagem Celular , Citocinas/biossíntese , Primers do DNA , Ativação Enzimática , Genes Reporter , Lipopolissacarídeos/farmacologia , Luciferases/genética , Macrófagos/efeitos dos fármacos , Macrófagos/enzimologia , Camundongos , NF-kappa B/metabolismo , Fosforilação
20.
Appl Opt ; 46(20): 4371-5, 2007 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-17579691

RESUMO

A piezoelectric optical fiber stretcher has been introduced for working point controlling and low-frequency noise suppression of a fiber-optic atmospheric turbulence sensor. It is actuated by a piezoelectric ceramic stack. The rational structure allows the fiber to extend only along the axial direction, which minimizes the nonlinear birefringence effects for the optical phase shift. What is believed to be a novel method has been proposed to measure its phase-shift coefficient. With the use of this device, the fiber-optic atmospheric turbulence sensor has been tested for the air refractive index measurement.

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