Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 131
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
2.
Eur J Clin Microbiol Infect Dis ; 33(4): 591-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24136062

RESUMO

A contaminated hospital environment has been identified as an important reservoir of pathogens causing healthcare-associated infections. This study is to evaluate the efficacy of bacteria killing nanotechnology Bio-Kil on reducing bacterial counts in an intensive care unit (ICU). Two single-bed rooms (S-19 and S-20) in the ICU were selected from 7 April to 27 May 2011. Ten sets of new textiles (pillow cases, bed sheets, duvet cover, and patient clothing) used by patients in the two single-bed rooms were provided by the sponsors. In the room S-20, the 10 sets of new textiles were washed with Bio-Kil; the room walls, ceiling, and air-conditioning filters were treated with Bio-Kil; and the surfaces of instruments (respirator, telephone, and computer) were covered with Bio-Kil-embedded silicon pads. Room S-19 served as the control. We compared the bacterial count on textiles and environment surfaces as well as air samples between the two rooms. A total of 1,364 samples from 22 different sites in each room were collected. The mean bacterial count on textiles and environmental surfaces in room S-20 was significantly lower than that in room S-19 (10.4 vs 49.6 colony-forming units [CFU]/100 cm(2); P < 0.001). Room S-20 had lower bacterial counts in air samples than room S-19 (33.4-37.6 vs 21.6-25.7 CFU/hour/plate; P < 0.001). The density of microbial isolations was significantly greater among patients admitted to room S-19 than those to room S-20 (9.15 vs 5.88 isolates per 100 patient-days, P < 0.05). Bio-Kil can significantly reduce bacterial burden in the environment of the ICU.


Assuntos
Controle de Infecções/métodos , Unidades de Terapia Intensiva , Nanotecnologia/métodos , Esterilização/métodos , Contagem de Colônia Microbiana , Humanos , Esterilização/instrumentação
3.
Artigo em Inglês | MEDLINE | ID: mdl-23573928

RESUMO

This article presents an innovative design for inoculating the desired organisms to stratified geological layers at desired rates during in-situ bioaugmentation. The new delivery system consists of intermittent porous tubes connected in series with impermeable polyethylene tubes that run horizontally in each stratified layer of a contaminated aquifer. A bioaugmentation test using the new delivery system was conducted to inject an enriched culture of Escherichia coli (E. coli). Results of the test indicated that the distribution of E. coli through each porous tube was fairly uniform. A mathematical model previously developed to calculate the distribution of water flow through each porous tube was modified to calculate the distribution of E. coli. Geological layers often have different hydraulic conductivities. By controlling the permeability and the length of porous tubes placed in stratified layers, the new design provides a means to selectively deliver aqueous bacteria to various layers at desired rates according to aquifer heterogeneity.


Assuntos
Biodegradação Ambiental , Recuperação e Remediação Ambiental/métodos , Escherichia coli/fisiologia , Água Subterrânea/química , Água Subterrânea/microbiologia , Modelos Teóricos , Permeabilidade , Porosidade , Movimentos da Água
4.
Vox Sang ; 102(4): 277-84, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22092109

RESUMO

BACKGROUND: A solvent/detergent (S/D) treatment in a medical device has been developed for pathogen reduction of plasma for transfusion. Impact of S/D on bacterial growth and on the capacity of complement to kill bacteria has been investigated in this study. STUDY DESIGN AND METHODS: A pool of apheresis plasma from four donors was spiked with eight transfusion-relevant bacteria. Plasma was treated with 1% tri(n-butyl) phosphate and 1% Triton X-45 at 31°C for 90 min and then extracted by oil at 31°C for 70 min. Decomplemented plasma and Phosphate Buffer Saline were used as controls. Bacterial count was determined in samples taken immediately after spiking, or after S/D and oil treatment. Similar experiments were conducted using three individual recovered plasma donations. Bacteria growth inhibition tests were performed using discs soaked with plasma samples whether containing the S/D agents or not. RESULTS: The mean reduction factors of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae due to complement during S/D treatment were >8·75, 4·71, and 4·18 log in pooled plasma and >7·42, 2·24 and >6·08 log in individual plasmas, respectively. Bacillus cereus and Bacillus subtilis were inactivated by S/D (>7·04 and 1·60 log in pooled, and >6·06 and 2·39 in individual plasmas, respectively). Staphylococcus aureus, Staphylococcus epidermidis and Enterobacter cloacae did not multiply during S/D treatment of plasma. Growth inhibition tests revealed an inhibition of three gram-negative bacteria by complement and all gram-positive by S/D. CONCLUSION: The S/D treatment of plasma does not alter the bactericidal activity of complement, and inactivates some gram-positive bacteria.


Assuntos
Bactérias/efeitos dos fármacos , Detergentes/farmacologia , Plasma/efeitos dos fármacos , Reação Transfusional , Bactérias/crescimento & desenvolvimento , Transfusão de Sangue/normas , Proteínas do Sistema Complemento , Bactérias Gram-Negativas , Humanos , Plasma/microbiologia , Solventes/química
5.
J Intellect Disabil Res ; 56(6): 567-78, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21988314

RESUMO

BACKGROUND: Deficit in motor performance is common in children with intellectual disabilities (ID). A motor function measure with sound psychometric properties is indispensable for clinical and research use. The purpose of this study was to compare the psychometric properties of three commonly used clinical measures for assessing motor function in preschoolers with ID: the Bruininks-Oseretsky Test of Motor Proficiency-Second Edition, the Movement Assessment Battery for Children-Second Edition and the Peabody Developmental Motor Scale-Second Edition (PDMS-2). METHOD: One hundred and ninety-one children aged 3-6 years with ID were evaluated with the three measures at three time points: two baseline measurements with a 1-week interval before the intervention, and a follow-up measurement after 6 months of paediatric rehabilitation programme. One hundred and forty-one participants completed all of the assessments. The distribution (ceiling and floor effects) and reliability (internal consistency and test-retest reliability) of each measure were examined. Concurrent validity, predictive validity, and responsiveness were examined as well. RESULTS: All measures, except for the PDMS-2, had significant floor effects or ceiling effects at one or more time points. The three measures had good internal consistency (Cronbach α ≥ 0.86) and test-retest reliability (intraclass correlation coefficient ≥ 0.96). The Spearman ρ correlation coefficient for each pair of the three measures was ≥ 0.80, indicating high concurrent validity. The predictive validity of the three measures was satisfactory (Spearman ρ ≥ 0.52). The responsiveness of the three measures was moderate (0.47 ≤ effect size ≤ 0.74). The minimal detectable changes of the three measures were satisfactory. CONCLUSIONS: All three measures showed sufficient reliability, validity and responsiveness in preschoolers with ID, but the PDMS-2 is recommended for its superior psychometric properties.


Assuntos
Avaliação da Deficiência , Deficiência Intelectual/fisiopatologia , Deficiência Intelectual/reabilitação , Transtornos das Habilidades Motoras/fisiopatologia , Transtornos das Habilidades Motoras/reabilitação , Psicometria/métodos , Pré-Escolar , Feminino , Humanos , Masculino , Destreza Motora/fisiologia , Movimento/fisiologia , Psicometria/normas , Reprodutibilidade dos Testes
6.
Artigo em Inglês | MEDLINE | ID: mdl-22242881

RESUMO

Geological layers often have different hydraulic conductivities. This paper presents an innovative design for delivering aqueous substrates and nutrients to various stratified layers at desired rates during in-situ bio-stimulation. The new delivery system consists of intermittent porous tubes connected in series with impermeable polyethylene tubes that run horizontally in each stratified layer of a contaminated aquifer. Results of the tracer test indicated that the distribution of tritium through each porous tube was fairly uniform. A mathematical model was also developed to calculate the distribution of water flow through each porous tube. By controlling the permeability and the length of porous tubes placed in stratified layers, the new design provides a means to selectively deliver nutrients to various layers at desired rates according to aquifer heterogeneity.


Assuntos
Biodegradação Ambiental , Água Subterrânea , Purificação da Água/métodos , Geologia , Modelos Teóricos , Permeabilidade , Porosidade , Trítio/análise , Movimentos da Água , Purificação da Água/instrumentação
7.
Sci Rep ; 12(1): 2346, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35173182

RESUMO

Graphene is known as an atomically thin, transparent, highly electrically and thermally conductive, light-weight, and the strongest 2D material. We investigate disruptive application of graphene as a target of laser-driven ion acceleration. We develop large-area suspended graphene (LSG) and by transferring graphene layer by layer we control the thickness with precision down to a single atomic layer. Direct irradiations of the LSG targets generate MeV protons and carbons from sub-relativistic to relativistic laser intensities from low contrast to high contrast conditions without plasma mirror, evidently showing the durability of graphene.

8.
Vox Sang ; 101(3): 215-20, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21521235

RESUMO

BACKGROUND AND OBJECTIVES: TGF-ß1 exerts important physiological functions in osteogenesis and chondrogenesis and may be of therapeutic interest. The aim of this work was to develop a scalable purification process of TGF-ß1 from virally inactivated human platelets. STUDY DESIGN AND METHODS: Apheresis platelet concentrates (N=12) were solvent/detergent (S/D) treated (1% TnBP/1% Triton X-45; 31°C) and the resulting platelet lysates were clarified by oil extraction and centrifugation, then chromatographed on an anion-exchange DEAE-Sepharose Fast-Flow column equilibrated in a PBS buffer, pH 7.5. The column was washed to eliminate unbound proteins and the S/D agents. Bound proteins were eluted using a 1 M NaCl-PBS buffer pH 7.5 (DEAE-eluate). The content in TGF-ß1, PDGF-AB, VEGF, IGF-1, EGF, and b-FGF was measured by ELISA. Proteins, lipids, and S/D agents were assessed. Protein profile was determined by SDS-PAGE under reduced or non-reduced conditions. RESULTS: Most proteins, including albumin and immunoglobulins G, A, and M did not bind to the DEAE column as evidenced also by SDS-PAGE. Essentially all PDGF, VEGF, and IGF were in the breakthrough. The DEAE-eluate contained close to 60% of the TGF-ß1 at a mean concentration of about 102 ng/ml, whereas EGF, b-FGF were at about 0.72 and 0.18 ng/ml, respectively. The content in TnBP and Triton X-45 was <2 ppm. CONCLUSION: A fraction enriched in TGF-ß1 can be prepared from virally inactivated human platelet lysates using an easily scale process. Its interest in regenerative medicine and cell therapy will be evaluated in further studies.


Assuntos
Plaquetas/química , Fator de Crescimento Transformador beta1/química , Fator de Crescimento Transformador beta1/isolamento & purificação , Inativação de Vírus , Plaquetas/virologia , Cromatografia por Troca Iônica/métodos , Citocinas/química , Humanos , Imunoglobulinas/química , Octoxinol/química
9.
Clin Nephrol ; 75(5): 397-402, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21543018

RESUMO

AIMS: Vascular calcification is a common complication among dialysis patients and its pathogenesis involves a variety of factors. The roles of pro-inflammatory cytokines and residual kidney function (RKF) in peritoneal dialysis (PD) patients with vascular calcification have not been investigated. MATERIALS AND METHODS: 157 stable PD patients were enrolled. All patients had plain X-ray film examination including chest (posterior-anterior view, CXR) and pelvis. Vascular calcification was interpreted as calcified deposit over aortic arch and linear calcification of pelvic arteries. Relevant biochemical data, pro-inflammatory markers, and PD-related factors were measured and collected. RESULTS: Vascular calcification prevalence in CXRs was higher than that in pelvis films (38.2% vs. 22.3%, p < 0.05). Patients with vascular calcification in CXR had higher incidence of calcification in pelvis films (p < 0.05). Only a minor portion (14.6%) had two calcification sites. Regression analysis revealed that age, PD duration, body mass index, and RKF were independent factors associated with vascular calcification in CXR. Age, diabetes, IL-10 and RKF were factors associated in pelvis films. Factors independently related to vascular calcification in both films were age, duration, diabetes, IL-10, and RKF. CONCLUSIONS: Besides traditional risk factors, IL-10 and RKF were important factors associated with vascular calcification in PD patients.


Assuntos
Calcinose/etiologia , Interleucina-10/fisiologia , Rim/fisiopatologia , Diálise Peritoneal/efeitos adversos , Doenças Vasculares/etiologia , Adulto , Idoso , Feminino , Humanos , Interleucina-10/sangue , Masculino , Pessoa de Meia-Idade , Radiografia Torácica , Fatores de Risco
10.
Science ; 230(4723): 319-22, 1985 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-2996131

RESUMO

Hepatitis B virus (HBV), a virus with known carcinogenic potential, integrates into cellular DNA during long-term persistent infection in man. Hepatocellular carcinomas isolated from viral carriers often contain clonally propagated viral DNA integrations. As small chromosomal deletions are associated with several types of carcinomas, the occurrence of chromosomal deletions in association with HBV integration in hepatocellular carcinoma was studied. HBV integration was accompanied by a deletion of at least 13.5 kilobases of cellular sequences in a human hepatocellular carcinoma. The viral DNA integration and deletion of cellular sequences occurred on the short arm of chromosome 11 at location 11p13-11p14. The cellular sequences that were deleted at the site of HBV integration were lost from the tumor cells, leaving only a single copy of the remaining cellular allele.


Assuntos
Carcinoma Hepatocelular/genética , Deleção Cromossômica , Cromossomos Humanos 6-12 e X , Vírus da Hepatite B/genética , Neoplasias Hepáticas/genética , Animais , Sequência de Bases , Carcinoma Hepatocelular/microbiologia , Clonagem Molecular , Enzimas de Restrição do DNA , DNA Viral/genética , Humanos , Células Híbridas/citologia , Neoplasias Hepáticas/microbiologia , Camundongos , Hibridização de Ácido Nucleico
11.
Vox Sang ; 97(2): 119-28, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19320900

RESUMO

BACKGROUND: Human platelet growth factors (HPGF) are essential for tissue regeneration and may replace fetal bovine serum (FBS) in cell therapy. No method for the manufacture of standardized virally inactivated HPGF has been developed yet. STUDY DESIGN AND METHODS: Platelet concentrates (PC) were subjected to solvent/detergent (S/D) treatment (1% TnBP/1% Triton X-45), oil extraction, hydrophobic interaction chromatography and sterile filtration. Platelet-derived growth factor (PDGF)-AB, -BB and -AA, transforming growth factor-beta1 (TGF-beta1), epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1) and vascular endothelium growth factor (VEGF) were measured by ELISA. Composition in proteins and lipids was determined, protein profiles were obtained by SDS-PAGE, and TnBP and Triton X-45 were assessed by gas chromatography and high-performance liquid chromatography, respectively. Cell growth promoting activity of HPGF was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay using human embryonic kidney (HEK293A) fibroblast and Statens Seruminstitute rabbit corneal (SIRC) epithelial cell lines. RESULTS: The GF preparation contained a mean of 16.66, 2.04, 1.53, 72.19, 0.33, 48.59 and 0.44 ng/ml of PDGF-AB, -BB, -AA, TGF-beta1, EGF, IGF-1 and VEGF, respectively. The protein profile was typical of platelet releasates and had less than 2 p.p.m. of residual S/D agents. MTS assay of HEK293A and SIRC cultures showed that the GF preparation at 10% and 0.1% (v/v), respectively, could successfully replace 10% FBS for cell proliferation. Cell-stimulating activity of HPGF on HEK293A was over twice that of PC releasates. CONCLUSION: STANDARDIZED and functional virally inactivated HPGF can be prepared from human PC for possible applications in cell therapy and regenerative medicine.


Assuntos
Plaquetas/química , Peptídeos e Proteínas de Sinalização Intercelular/isolamento & purificação , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Transplante de Células/métodos , Fracionamento Químico/métodos , Ensaio de Imunoadsorção Enzimática , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Coelhos , Medicina Regenerativa/métodos
12.
Eur Rev Med Pharmacol Sci ; 23(14): 6346-6351, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31364142

RESUMO

OBJECTIVE: G protein-coupled receptors (GPCRs) constitute the largest membrane proteins superfamily. However, the interactions between them and the coupled heterotrimeric G proteins were little known. To get a deeper view of how the receptor bound to the G protein, we carried out the molecular dynamics' simulations of human Beta2 adrenoceptors (ß1 and ß2) and G protein (s and I) alpha subunit complexes by homology modeling. MATERIALS AND METHODS: For homology modeling, the program modeller 9.11 was used with automodel module. Before dynamics simulation, the homology models were prepared by Protein Preparation Wizard module in Maestro 9.3. The Desmond program was used to perform molecular minimization and molecular dynamics simulation under OPLS-All atom 2005 force field with default parameters. RESULTS: The results offered us the mechanism vividly in molecular level: (1) GPCR-G protein complex can be simulated without specific nanobody; (2) the G protein activation ability of GPCR can be explained by molecular dynamics simulation. CONCLUSIONS: It is suggested that we could do molecular dynamics simulation of complex of GPCR-G protein without bound nanobody. Secondly, the simulation time reduced greatly by using homology modeling to generate complex of proteins. Thirdly, the molecular dynamics simulation will help us to know or even predict further protein-protein interactions.


Assuntos
Proteínas de Ligação ao GTP/química , Proteínas de Ligação ao GTP/metabolismo , Receptores Adrenérgicos beta 2/química , Receptores Adrenérgicos beta 2/metabolismo , Sítios de Ligação , Biologia Computacional/métodos , Humanos , Modelos Moleculares , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Sódio/metabolismo , Homologia Estrutural de Proteína
13.
Br J Cancer ; 99(9): 1453-61, 2008 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-18841160

RESUMO

beta2-Microglobulin (beta2M), a component of MHC class I molecules, is believed to be associated with tumour status in various cancers. In this study, we examined the expression of beta2M at different malignant stages of oral cavity squamous cell carcinoma (OCSCC). To determine the possible correlation between beta2M expression and various clinical characteristics, 256 samples from patients with OCSCC were evaluated by immunohistochemical staining. Strong beta2M expression was significantly correlated with a relatively advanced tumour stage (P<0.001), positive nodal status (P<0.001), and TNM stage (P<0.001). The cumulative 5-year survival rate was significantly correlated with a relatively advanced tumour stage (P<0.001), positive nodal status (P<0.001), TNM stage (P<0.001), and strong expression of beta2M (P<0.001). Thus, elevated beta2M expression is an indicator of poor survival (P<0.001). In addition, we extended our analysis of beta2M expression to the FaDu and SCC25 oral cancer cell lines. beta2-Microglobulin expression was positively correlated with cell migration and invasion in beta2M-overexpressing transfectants in Transwell chambers. The suppression of beta2M expression using small interfering RNA (siRNA) was sufficient to decrease cell migration and invasion in vitro. Taken together, our results suggest that beta2M expression in the tissues is associated with survival and may be involved in tumour progression and metastasis in OCSCC.


Assuntos
Carcinoma de Células Escamosas/patologia , Neoplasias Bucais/patologia , Microglobulina beta-2/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/mortalidade , Movimento Celular , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/química , Neoplasias Bucais/mortalidade , Invasividade Neoplásica , Estadiamento de Neoplasias , Microglobulina beta-2/análise , Microglobulina beta-2/antagonistas & inibidores , Microglobulina beta-2/genética
14.
J Intellect Disabil Res ; 52(12): 1048-60, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18557969

RESUMO

BACKGROUND: The purpose of the study was to describe sensorimotor profile in children with mild intellectual disability (ID), and to examine the association between cognitive and motor function. METHODS: A total of 233 children with mild ID aged 7 to 8 years were evaluated with measures of cognitive, motor and sensory integrative functioning. RESULTS: Children with mild ID performed significantly less well on all test measures. 44.2% of children scored in the impaired range on seven out of 22 sensorimotor measures. They had weaker fine motor skills than gross motor skills. Sensory integrative functions were only mildly impaired. Total IQ substantially predicted overall performance on each motor test. Specifically, verbal comprehension and processing speed indexes were significant predictors of gross and fine motor function. CONCLUSIONS: Sensorimotor dysfunctions were found to be very frequent in children with mild ID. Early identification of sensorimotor impairments is essential to prompt early intervention and facilitate better integration into regular school settings.


Assuntos
Transtornos Cognitivos/diagnóstico , Deficiência Intelectual/diagnóstico , Transtornos das Habilidades Motoras/diagnóstico , Transtornos Psicomotores/diagnóstico , Criança , Transtornos Cognitivos/psicologia , Avaliação da Deficiência , Feminino , Humanos , Deficiência Intelectual/psicologia , Masculino , Programas de Rastreamento/estatística & dados numéricos , Transtornos das Habilidades Motoras/psicologia , Exame Neurológico/estatística & dados numéricos , Psicometria/estatística & dados numéricos , Transtornos Psicomotores/psicologia , Valores de Referência , Reprodutibilidade dos Testes , Sensação , Escalas de Wechsler/estatística & dados numéricos
15.
Oncogene ; 36(29): 4234, 2017 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-28319058

RESUMO

This corrects the article DOI: 10.1038/onc.2015.397.

16.
Eur J Surg Oncol ; 32(3): 353-7, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16455224

RESUMO

AIM: To evaluate the functional outcomes of patients who underwent total or nearly total glossectomy for advanced tongue or base of tongue cancer. MATERIAL AND METHODS: We used the radial forearm free flap (RFFF), anterior lateral thigh flap (ALTF) or fibular osteocutaneous flap (FOCF) to reconstruct the oral defect after radical resection in 39 patients undergoing total or nearly total glossectomy with laryngeal preservation. RESULTS: Good functional outcomes, measured by independent feeding, speech and swallowing were achieved in 35, 36 and 35 patients, respectively. The cumulative 4-year survival rates were 63.8% for tongue cancer and 42.9% for base of tongue cancer. CONCLUSION: Reconstruction with free flaps is a feasible method to restore the functional outcomes in speech and deglutition among patients who undergo total or nearly total glossectomy with laryngeal preservation.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Ablação por Cateter , Glossectomia/métodos , Retalhos Cirúrgicos , Neoplasias da Língua/cirurgia , Adulto , Idoso , Carcinoma de Células Escamosas/patologia , Deglutição/fisiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fala/fisiologia , Neoplasias da Língua/patologia , Neoplasias da Língua/fisiopatologia , Resultado do Tratamento
17.
Oncogene ; 35(26): 3387-98, 2016 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-26500058

RESUMO

Secondary mutation of epidermal growth factor receptor (EGFR) resulting in drug resistance is one of the most critical issues in lung cancer therapy. Several drugs are being developed to overcome EGFR tyrosine kinase inhibitor (TKI) resistance. Here, we report that pyruvate kinase M2 (PKM2) stabilized mutant EGFR protein by direct interaction and sustained cell survival signaling in lung cancer cells. PKM2 silencing resulted in markedly reduced mutant EGFR expression in TKI-sensitive or -resistant human lung cancer cells, and in inhibition of tumor growth in their xenografts, concomitant with downregulation of EGFR-related signaling. Mechanistically, PKM2 directly interacted with mutant EGFR and heat-shock protein 90 (HSP90), and thus stabilized EGFR by maintaining its binding with HSP90 and co-chaperones. Stabilization of EGFR relied on dimeric PKM2, and the protein half-life of mutant EGFR decreased when PKM2 was forced into its tetramer form. Clinical levels of PKM2 positively correlated with mutant EGFR expression and with patient outcome. These results reveal a previously undescribed non-glycolysis function of PKM2 in the cytoplasm, which contribute to EGFR-dependent tumorigenesis and provide a novel strategy to overcome drug resistance to EGFR TKIs.


Assuntos
Receptores ErbB/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Neoplasias Pulmonares/metabolismo , Piruvato Quinase/metabolismo , Células A549 , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Citosol/enzimologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Humanos , Immunoblotting , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Mutação , Ligação Proteica , Inibidores de Proteínas Quinases/farmacologia , Estabilidade Proteica , Piruvato Quinase/genética , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sobrevida , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/genética , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Biochim Biophys Acta ; 1437(2): 223-34, 1999 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-10064905

RESUMO

Ganodermic acid S (GAS), a membrane acting agent, exerts multiple effects on human platelet function (C.N. Wang et al. (1991) Biochem. J. 277, 189-197). The study reported how GAS affected the response of human gel-filtered platelets (GFP) to collagen. The agent inhibited cell aggregation by prolonging lag and shape change periods and decreasing the initial cell aggregation rate. However, the inhibitory efficiency was less than its inhibition on GFP response to U46619, a thromboxane (TX) A2 mimetic. In the agent-effect on biochemical events, GAS effectively inhibited Ca2+ mobilization, phosphorylation of myosin light chain, dense granule secretion and TXB2 generation. The inhibitions might originate from blocking Ca2+ mobilization of the TXA2-dependent pathway. GAS partially decreased the phosphorylation of most phosphotyrosine proteins from early activation to the integrin alphaIIbbeta3-regulated steps. The agent did not affect the phosphorylation of three proteins at the steps regulated by integrin alphaIIbbeta3. The results suggest that GAS inhibits the collagen response predominantly on the TXA2-dependent signaling, and the tyrosine kinase-dependent pathway in collagen response plays a major role in aggregation.


Assuntos
Plaquetas/efeitos dos fármacos , Colágeno/farmacologia , Lanosterol/análogos & derivados , Inibidores da Agregação Plaquetária/farmacologia , Tromboxano A2/metabolismo , Plaquetas/enzimologia , Plaquetas/metabolismo , Cálcio/metabolismo , Colágeno/antagonistas & inibidores , Humanos , Lanosterol/farmacologia , Fosforilação , Proteínas Tirosina Quinases/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
19.
Int J Oral Maxillofac Surg ; 34(3): 311-20, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15741041

RESUMO

The aim of this study was to design a biodegradable implant, in the form of a reconstituted collagen template in order to promote and support regeneration of the temporomandibular joint disc. Bovine collagen (Major Type I) was pepsinized, reduced by beta-mercaptoethanol, and reconstituted by glutaraldehyde. The reconstitution of the collagen increased the resistance to biological degradation by collagenase, optimized the pore size and possessed maximum biological activity for tissue regeneration. Forty-four New Zealand rabbits underwent either sham surgical procedures or partial temporomandibular joint discectomy. In animals that underwent partial discectomy, the discs were replaced by either reconstituted collagen templates or subdermal grafts. Some of the surgerized animals did not receive any type of implant or disc substitute. Gross and histological examination of the surgerized temporomandibular joints was carried out at 1-, 2-, and 3-month intervals after surgery on the selected groups of animals. Marked arthritic changes were observed after 3 months in the partially discectomized joints without implantation. In contrast, the discs, which received a reconstituted collagen template or subdermal graft exhibited regeneration and nearly normal morpology. No foreign body response was observed in experimental groups 3 months after implantation. This study demonstrated that the reconstituted collagen did as well as subdermal grafts in supporting and facilitating regeneration of the disc and the former was found to have some advantages over the latter.


Assuntos
Implantes Absorvíveis , Regeneração Óssea/efeitos dos fármacos , Colágeno Tipo I/farmacologia , Disco da Articulação Temporomandibular/efeitos dos fármacos , Animais , Transplante Ósseo , Bovinos , Reação a Corpo Estranho , Masculino , Coelhos , Disco da Articulação Temporomandibular/fisiologia , Disco da Articulação Temporomandibular/cirurgia
20.
Exp Hematol ; 19(2): 122-7, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1991494

RESUMO

The production of colony-stimulating factors (CSFs) by murine bone marrow stromal cells was studied with Dexter long-term bone marrow culture (LTBMC). For induction of CSF release, various concentrations (0.5-40.0 microgram/ml) of bacterial lipopolysaccharide (LPS) were added to nonrecharged 3-week-old LTBMCs consisting of an intact or macrophage-depleted adherent cell layer. The depletion of monocytes/macrophages from freshly prepared bone marrow cell suspension was performed by carbonyl-iron incorporation before establishment of LTBMC. The supernatants (Sup) of normal LTBMCs contained a low level of macrophage colony-stimulating factor (M-CSF) that was produced by the adherent cells but not by the nonadherent cell elements. No colony inhibitor was found in the Sup of LTBMCs, whereas a colony-promoting activity (CPA) was detected in medium conditioned by the adherent marrow cells (AC-CM). CPA could enhance the colony formation of myeloid progenitor cells when used in combination with recombinant murine granulocyte-macrophage colony-stimulating factor (GM-CSF). The production of CSFs peaked at about 24 h after refeeding, but it then declined to only half the optimal activity at the end of the week. Addition of LPS to the intact LTBMC invariably increased the production of a GM-CSF-like cytokine. The release of this cytokine was dose dependent and peaked at a dosage of 20 micrograms/ml of LPS at 24 h after treatment. In contrast, macrophage-depleted marrow-adherent cells failed to respond to LPS for CSF secretion. These results suggest that LPS can stimulate marrow macrophages to directly release CSF or to potentiate the production of CSF by other stromal cells.


Assuntos
Células da Medula Óssea , Fatores Estimuladores de Colônias/metabolismo , Lipopolissacarídeos/farmacologia , Animais , Medula Óssea/metabolismo , Medula Óssea/fisiologia , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Células Cultivadas , Relação Dose-Resposta a Droga , Cinética , Lipopolissacarídeos/farmacocinética , Camundongos , Camundongos Endogâmicos ICR
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA