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1.
Bone Joint J ; 99-B(6): 818-823, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28566403

RESUMO

AIMS: We assessed the long-term (more than ten-year) outcomes of the Kudo type-5 elbow prosthesis in patients with rheumatoid arthritis (RA). MATERIALS AND METHODS: We reviewed 41 elbows (Larsen Grade IV, n = 21; Grade V, n = 20) in 31 patients with RA who had undergone a Kudo type-5 total elbow arthroplasty (TEA) between 1994 and 2003, and had been followed up for more than ten years. The humeral component was cementless and the all-polyethylene ulnar component cemented in every patient. Clinical outcome was assessed using the Mayo elbow performance score. We calculated the revision rate and evaluated potential risk factors for revision. The duration of follow-up was a mean 141 months (120 to 203). RESULTS: Aseptic loosening of the ulnar component occurred in 11 elbows. There was no radiolucency around any humeral component. There was one deep infection. The survival rate according to Kaplan-Meier survivorship analysis was 87.8% after five years and 70.7% after ten years. The range of extension/flexion was a mean -38° (-80° to 0°)/105° (30° to 150°) before surgery and -40° (-70° to -20°)/132° (100° to 150°) at the final follow-up, while the mean Mayo elbow performance score was 43 before surgery and 80 at final follow-up. Disease duration of RA up to the TEA of < 15 years and a pre-operative range of movement (ROM) of > 85° were significant risk factors for revision or aseptic loosening. CONCLUSION: Although Kudo type-5 prostheses gave satisfactory results in the short-term, aseptic loosening increased after five years. In most cases, elbow function was maintained in the long-term without loosening of the implant. A short duration from the onset of RA to TEA and a large pre-operative ROM were significant risk factors for revision or aseptic loosening. Cite this article: Bone Joint J 2017;99-B:818-23.


Assuntos
Artrite Reumatoide/cirurgia , Artroplastia de Substituição do Cotovelo/instrumentação , Prótese de Cotovelo , Adulto , Idoso , Artroplastia de Substituição do Cotovelo/efeitos adversos , Artroplastia de Substituição do Cotovelo/métodos , Cimentação , Articulação do Cotovelo/diagnóstico por imagem , Articulação do Cotovelo/fisiopatologia , Articulação do Cotovelo/cirurgia , Prótese de Cotovelo/efeitos adversos , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Falha de Prótese/etiologia , Radiografia , Recuperação de Função Fisiológica , Reoperação , Fatores de Risco
2.
Oper Dent ; 42(4): 387-395, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28402734

RESUMO

OBJECTIVE: To evaluate the masking ability and translucency of monolithic and bilayer CAD-CAM ceramic structures. METHODS: Discs of high translucency (HT) and low translucency (LT) lithium disilicate-based ceramic (IPS e.max CAD) with different thicknesses (0.7, 1, 1.5, and 2 mm) were evaluated as a monolithic structure or combined (bilayer) with a 0.5-mm-thick zirconia framework (IPS e.max ZirCAD). The masking ability and translucency were calculated based on CIE L*a*b* color coordinates measured with a spectrophotometer (SP60, X-Rite). The translucency parameter (TP) was calculated using color coordinates measured over standard white-and-black backgrounds. The masking ability was calculated by CIEDE2000 color difference metric (ΔE00) for each specimen measured over a tooth-colored substrate (shade A2) compared to three darker backgrounds (shade C4 and two metal substrates). Confidence intervals (CI) for the means (95% CI) were calculated for TP and ΔE00. The Pearson correlation between ΔE00 and TP was investigated for monolithic and bilayer structures over all backgrounds. RESULTS: The thinner the lithium disilicate layer, the greater the translucency and the higher the ΔE00 values. The effect of ceramic thickness on both translucency and masking ability was more pronounced for the monolithic structures. In addition, monolayers always presented a greater color variation than their bilayer counterparts. The metallic background produced greater ΔE00 than the C4-shaded substrate. CONCLUSION: Monolithic veneers were able to mask C4-shaded background but did not mask metallic backgrounds. Bilayer structures showed greater shade masking ability than monolithic structures.


Assuntos
Silicatos de Alumínio/química , Cor , Desenho Assistido por Computador , Porcelana Dentária/química , Facetas Dentárias , Zircônio/química , Luz , Teste de Materiais , Espectrofotometria , Propriedades de Superfície
4.
Eur J Vasc Endovasc Surg ; 48(6): 695-702, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25281532

RESUMO

OBJECTIVE: To assess and risk-stratify the medium-term clinical outcomes after infrainguinal bypass grafting (IBG) to treat critical limb ischaemia (CLI) in patients with end-stage renal disease. METHODS: This was a retrospective single-centre study. Between April 2007 and March 2011, 112 limbs from 89 patients were studied. In particular, amputation-free survival (AFS), 30 day mortality, freedom from major adverse limb events (MALE), limb salvage, and overall survival were examined. The aim was to identify outcome predictors. RESULTS: Eight patients (9%) died within 30 days of IBG. The only positive predictor of 30-day mortality was an ejection fraction (EF) < 40% (hazard ratio [HR] 5.57, 95% confidence interval [CI] 1.16-26.83; p = .03). The mean follow-up duration was 14 months. The 1- and 2-year AFS rates were 64% and 43%, respectively, and the rates of freedom from MALE were 81% and 77%, respectively. In addition, the 1- and 2-year limb salvage rates were 89% and 85%, and the survival rates were 68% and 50%, respectively. Non-ambulatory status was negatively associated with AFS (HR 3.04, 95% CI 1.59-5.82; p < .01), freedom from MALE (HR 4.98, 95% CI 1.91-12.96; p < .01), and limb salvage (HR 5.18, 95% CI 1.47-18.30; p = .01). The other negative predictors of overall survival were a serum albumin level <3.0 g/dL (HR 2.26, 95% CI 1.12-4.58; p = .02) and an EF <40% (HR 2.24, 95% CI 1.05-4.79; p = .04). CONCLUSION: Patients with CLI on dialysis enjoyed satisfactory freedom from MALE and limb salvage, but survival and AFS were significantly less than reported for IBG in patients with CLI who did not receive dialysis. In addition, patients with an EF <40%, lower serum albumin (<3.0 g/dL), or non-ambulatory status experienced particularly poor clinical outcomes after IBG.


Assuntos
Isquemia/cirurgia , Falência Renal Crônica/terapia , Diálise Renal , Enxerto Vascular , Idoso , Idoso de 80 Anos ou mais , Amputação Cirúrgica , Biomarcadores/sangue , Estado Terminal , Intervalo Livre de Doença , Feminino , Humanos , Isquemia/complicações , Isquemia/diagnóstico , Isquemia/mortalidade , Isquemia/fisiopatologia , Japão , Estimativa de Kaplan-Meier , Falência Renal Crônica/complicações , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/mortalidade , Salvamento de Membro , Masculino , Modelos de Riscos Proporcionais , Diálise Renal/efeitos adversos , Diálise Renal/mortalidade , Reoperação , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Albumina Sérica/metabolismo , Albumina Sérica Humana , Volume Sistólico , Fatores de Tempo , Resultado do Tratamento , Enxerto Vascular/efeitos adversos , Enxerto Vascular/mortalidade
5.
J Comp Pathol ; 147(4): 430-40, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22789858

RESUMO

The specific signalling pathways that are deregulated in canine endothelial tumours have not yet fully elucidated. Therefore, the aim of the present study was to examine activation of the Akt/mammalian target of rapamycin (mTOR)/eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) signalling pathway in spontaneously arising canine haemangiomas (HAs) and haemangiosarcomas (HSAs) in order to identify novel molecular targets for treatment. Surgically-resected samples of HA (n = 27), HSA (n = 37), granulation tissue (n = 4) and normal skin (n = 4) were investigated by immunohistochemistry. Approximately 80% of the HSA samples had moderate to intense expression of phosphorylated Akt at Ser473 (p-Akt Ser473), p-Akt Thr308, p-4E-BP1 Thr37/46 and eukaryotic initiation factor 4E, which was significantly higher than in the HAs and was similar to the expression in activated endothelial cells (ECs). Although p-mTOR complex1 (p-mTORC1) Ser2448 was expressed by most of the activated ECs, only 35% of the HSA samples had weak to moderate expression. Because mTORC2 and phosphorylates Akt Ser473 was activated in HSA samples, the present findings suggest that the mTORC2/Akt/4E-BP1 pathway, regulated independently of mTORC1, may be important for targeting therapy in canine HSAs.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Doenças do Cão/metabolismo , Hemangioma/veterinária , Hemangiossarcoma/veterinária , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Cutâneas/veterinária , Serina-Treonina Quinases TOR/metabolismo , Animais , Biomarcadores Tumorais/metabolismo , Doenças do Cão/patologia , Cães , Feminino , Hemangioma/metabolismo , Hemangioma/patologia , Hemangiossarcoma/metabolismo , Hemangiossarcoma/patologia , Imuno-Histoquímica/veterinária , Masculino , Transdução de Sinais , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia
6.
J Bone Joint Surg Br ; 94(7): 998-1006, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22733960

RESUMO

For the treatment of ununited fractures, we developed a system of delivering magnetic labelled mesenchymal stromal cells (MSCs) using an extracorporeal magnetic device. In this study, we transplanted ferucarbotran-labelled and luciferase-positive bone marrow-derived MSCs into a non-healing femoral fracture rat model in the presence of a magnetic field. The biological fate of the transplanted MSCs was observed using luciferase-based bioluminescence imaging and we found that the number of MSC derived photons increased from day one to day three and thereafter decreased over time. The magnetic cell delivery system induced the accumulation of photons at the fracture site, while also retaining higher photon intensity from day three to week four. Furthermore, radiological and histological findings suggested improved callus formation and endochondral ossification. We therefore believe that this delivery system may be a promising option for bone regeneration.


Assuntos
Fraturas do Fêmur/terapia , Consolidação da Fratura/fisiologia , Fraturas não Consolidadas/terapia , Campos Magnéticos , Transplante de Células-Tronco Mesenquimais , Animais , Regeneração Óssea/fisiologia , Diferenciação Celular/fisiologia , Movimento Celular , Dextranos , Modelos Animais de Doenças , Feminino , Fraturas do Fêmur/patologia , Fraturas do Fêmur/fisiopatologia , Fraturas não Consolidadas/patologia , Fraturas não Consolidadas/fisiopatologia , Medições Luminescentes/métodos , Nanopartículas de Magnetita , Células-Tronco Mesenquimais/patologia , Células-Tronco Mesenquimais/fisiologia , Ratos , Ratos Endogâmicos Lew
7.
J Comp Pathol ; 141(2-3): 199-203, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19505696

RESUMO

Angiogenic homeobox genes regulate the behaviour of endothelial cells (ECs) during angiogenesis, so the aim of this study was to determine whether expression of these genes may be a determinant of malignancy in canine haemangiosarcoma (HSA). Homeobox proteins were evaluated immunohistochemically in tissue samples from canine HSAs (n=78), haemangiomas (HAs; n=30) and samples of granulation tissue (n=8). Active ECs in granulation tissue were positively labelled by antisera specific for HoxA9, HoxB3, HoxD3, HoxB7, Pbx1 and Meis1. Quiescent ECs in granulation tissue did not express HoxD3 and Pbx1. There were significantly more neoplastic cells positively labelled for HoxA9, HoxB3, HoxD3 and Pbx1 in HSA compared with HA. Almost all tumours were positive for HoxB7 and Meis1. HoxB3, HoxD3, Pbx1 and Meis1 proteins were detected in 80-90% of the HSAs, but in <20% of the HAs. Overall, homeobox protein expression in HSA appears to have a phenotype similar to that of active ECs in angiogenesis. The expression of homeobox genes associated with angiogenesis might be associated with the malignant growth of HSA.


Assuntos
Doenças do Cão/patologia , Hemangioma/patologia , Hemangiossarcoma/patologia , Proteínas de Homeodomínio/metabolismo , Imuno-Histoquímica/veterinária , Neoplasias Vasculares/patologia , Animais , Biomarcadores Tumorais/metabolismo , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Cães , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Hemangioma/metabolismo , Hemangiossarcoma/metabolismo , Imuno-Histoquímica/métodos , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Neoplasias Vasculares/metabolismo
8.
Acta Biomater ; 5(6): 2322-30, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19332383

RESUMO

Apatite depositions from simulated body fluid (SBF) have been widely used for the in vitro assessment of the bioactivity of bone- and dental-implant materials. In previous work, we reported that titanium-based implant materials can be coated with an anodic TiO(2) nanotube layer which can significantly stimulate apatite formation. In the present work, we demonstrate that the tubular nature of such coatings makes them highly suitable for the application of a treatment called "alternative immersion method (AIM)", which preloads the coatings with synthetic hydroxyapatite. This treatment is indeed found to additionally promote natural apatite formation significantly. To study the AIM effect, layers of nanotubes with various diameters and crystal structures (amorphous, anatase/rutile) were produced, AIM-treated, and the formation of apatite in SBF10 (10mmol1(-1) HCO(3)(-)) was evaluated. The results show a drastic enhancement of apatite deposition rates (in some cases >20-fold acceleration) for AIM-treated TiO(2) nanotube layers in comparison with non-treated TiO(2) surfaces.


Assuntos
Líquidos Corporais/química , Substitutos Ósseos/química , Materiais Revestidos Biocompatíveis/química , Hidroxiapatitas/química , Nanotubos/química , Nanotubos/ultraestrutura , Titânio/química , Teste de Materiais , Propriedades de Superfície
9.
Histol Histopathol ; 24(4): 437-46, 2009 04.
Artigo em Inglês | MEDLINE | ID: mdl-19224446

RESUMO

We performed immunohistochemical investigation of the basement membrane (BM) components, namely, type IV collagen and laminin, in 83 canine hemangiosarcomas (HSAs), 22 hemangiomas, and some granulation tissues (GTs). Additionally, we analyzed the expression and activities of matrix metalloproteinase (MMP)-2, MMP-9, and membrane type 1-MMP (MT1-MMP) using the same samples by immunohistochemistry and gelatin zymography to investigate whether MMPs were associated with the BM degradation. In immunohistochemistry for the BM components, many HSAs showed discontinuous linear/negative immunoreactivity in the BM (type IV collagen: 49.4%/14.5%, laminin: 60.3%/10.8%, respectively). In contrast, almost all hemangiomas showed continuous staining in the BM (type IV collagen: 90.9%, laminin: 95.5%, respectively). Interestingly, positive cytoplasmic immunoreactivity for type IV collagen and laminin was observed in 97.6% and 91.6% HSA, respectively. Although MMP-9 immunoreactivity wasn't detected in neoplastic and active angiogenic endothelial cells (ECs), MMP-2 was detected in all ECs of GTs and in neoplastic cells of both vascular tumors. A strong immunoreactivity for MT1-MMP was observed in active angiogenic ECs in GTs and in neoplastic ECs in HSAs. However, almost all hemangiomas showed weak/negative immunoreactivity. In gelatin zymography, significantly strong activity of active MMP-2 was observed in HSAs, similar to that in active angiogenesis in GTs; however, weak/no activity of active MMP-2 was detected in hemangiomas. In canine HSA, neoplastic cells had active MMP-2, possibly activated by MT1-MMP, and discontinuous status of BM might be associated with activity of active MMP-2.


Assuntos
Colágeno Tipo IV/metabolismo , Doenças do Cão/enzimologia , Doenças do Cão/patologia , Hemangioma/veterinária , Hemangiossarcoma/veterinária , Laminina/metabolismo , Metaloproteinase 14 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Pró-Colágeno/metabolismo , Animais , Membrana Basal/metabolismo , Membrana Basal/patologia , Cães , Células Endoteliais/enzimologia , Células Endoteliais/patologia , Tecido de Granulação/enzimologia , Tecido de Granulação/patologia , Hemangioma/enzimologia , Hemangioma/patologia , Hemangiossarcoma/enzimologia , Hemangiossarcoma/patologia , Metaloproteinase 9 da Matriz/metabolismo
10.
J Comp Pathol ; 139(1): 1-7, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18479697

RESUMO

To investigate whether anti-apoptotic factors play a role in the malignant growth of canine haemangiosarcomas (HSAs), 83 HSAs and 22 haemangiomas were examined immunohistochemically for bcl-2 and survivin expression. Additionally, bcl-2 and survivin mRNA expression was quantified by semiquantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). Immunolabelling for bcl-2 was observed in 50 of the 83 HSA samples (60.2%) but in none of the haemangiomas. The average survivin positive index was 24.7% in the HSAs and 0.6% in the haemangiomas. In contrast to the high average value for survivin mRNA expression, which was approximately six times that for the haemangiomas, no significant difference was observed between HSAs and haemangiomas for the average bcl-2 mRNA expression level. The discrepancy between bcl-2 mRNA and bcl-2 protein expression requires further investigation, but the results suggest that malignant proliferation in canine HSAs is associated with bcl-2 and survivin expression.


Assuntos
Doenças do Cão/metabolismo , Hemangioma/veterinária , Hemangiossarcoma/veterinária , Proteínas de Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Neoplasias Vasculares/veterinária , Animais , Apoptose , Proliferação de Células , Doenças do Cão/patologia , Cães , Regulação Neoplásica da Expressão Gênica , Hemangioma/metabolismo , Hemangioma/patologia , Hemangiossarcoma/metabolismo , Hemangiossarcoma/patologia , RNA Mensageiro/metabolismo , Neoplasias Vasculares/metabolismo , Neoplasias Vasculares/patologia
11.
J Med Primatol ; 36(6): 335-42, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17976037

RESUMO

BACKGROUND: Equine herpesvirus 9 (EHV-9) is a new neurotropic equine herpesvirus which induced encephalitis in a variety of animals. However, there was no information on the susceptibility of EHV-9 in primates. METHODS: To assess the infectivity of EHV-9, four common marmosets (Callithrix jacchus) were inoculated by the nasal route with 10(6) plaque-forming units of EHV-9. RESULTS AND CONCLUSIONS: All of the inoculated animals exhibited various neurological signs progressing to collapse. Histologically, the affected animals had severe encephalitis characterized by neuronal degeneration and necrosis with intranuclear inclusion bodies, which extended from the olfactory bulb to the rhinencephalon and piriform lobe. Immunohistochemistry revealed EHV-9 antigens in degenerating neuronal cells. The nasal cavity had severe necrotizing rhinitis with prominent intra-nuclear inclusion bodies in the olfactory mucosa. These findings indicate that the marmosets are susceptible to EHV-9.


Assuntos
Callithrix , Encefalite Viral/veterinária , Infecções por Herpesviridae/veterinária , Doenças dos Macacos/virologia , Varicellovirus/patogenicidade , Administração Intranasal , Animais , Antígenos Virais/metabolismo , Encéfalo/patologia , Encéfalo/virologia , Encefalite Viral/patologia , Encefalite Viral/transmissão , Feminino , Infecções por Herpesviridae/fisiopatologia , Infecções por Herpesviridae/virologia , Masculino , Doenças dos Macacos/fisiopatologia , Neurônios/imunologia , Neurônios/metabolismo , Neurônios/patologia , Varicellovirus/imunologia
13.
Genes Cells ; 6(10): 869-76, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11683915

RESUMO

BACKGROUND: Hepatocyte growth factor/scatter factor (HGF/SF) induces cell scattering through the tyrosine kinase-type HGF/SF receptor, c-Met. We have previously shown that SHP-2, a protein tyrosine phosphatase, positively regulates the HGF/SF-induced cell scattering through modulating the activity of Rho to form stress fibres and focal adhesions. To further investigate the role of SHP-2 in HGF/SF-induced cell scattering, we have now examined the effect of a dominant active mutant of SHP-2 (SHP-2-DA). RESULTS: Expression of SHP-2-DA markedly increased the formation of lamellipodia with ruffles, while it decreased the accumulation of E-cadherin and beta-catenin at cell-cell adhesion sites in MDCK cells. In addition, expression of SHP-2-DA markedly enhanced cell scattering of MDCK cells in response to HGF/SF. Expression of SHP-2-DA induced the activation of MAP kinase without HGF/SF stimulation, whereas an inhibitor of MEK partly reversed the SHP-2-DA-induced morphological phenotypes. Furthermore, expression of either a dominant-active mutant of Rho or Vav2 also reversed the SHP-2-DA-induced morphological phenotypes. CONCLUSION: These results indicate that SHP-2 plays a crucial role in the HGF/SF-induced cell scattering through the regulation of two distinct small G proteins, Ras and Rho.


Assuntos
Proteínas Tirosina Fosfatases/metabolismo , Transativadores , Proteínas ras/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Caderinas/metabolismo , Adesão Celular/efeitos dos fármacos , Adesão Celular/genética , Linhagem Celular/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Proteínas do Citoesqueleto/metabolismo , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Genes Dominantes , Fator de Crescimento de Hepatócito/metabolismo , Fator de Crescimento de Hepatócito/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular , Sistema de Sinalização das MAP Quinases , Mutação , Proteína Tirosina Fosfatase não Receptora Tipo 11 , Proteína Tirosina Fosfatase não Receptora Tipo 6 , Proteínas Tirosina Fosfatases/efeitos dos fármacos , Proteínas Tirosina Fosfatases/genética , beta Catenina , Proteínas ras/efeitos dos fármacos , Proteínas rho de Ligação ao GTP/efeitos dos fármacos , Proteínas rho de Ligação ao GTP/genética
14.
J Biol Chem ; 276(22): 18941-6, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11262408

RESUMO

Gab-1 is a multiple docking protein that is tyrosine phosphorylated by receptor tyrosine kinases such as c-Met, hepatocyte growth factor/scatter factor receptor, and epidermal growth factor receptor. We have now demonstrated that cell-cell adhesion also induces marked tyrosine phosphorylation of Gab-1 and that disruption of cell-cell adhesion results in its dephosphorylation. An anti-E-cadherin antibody decreased cell-cell adhesion-dependent tyrosine phosphorylation of Gab-1, whereas the expression of E-cadherin specifically induced tyrosine phosphorylation of Gab-1. A relatively selective inhibitor of Src family kinases reduced cell-cell adhesion-dependent tyrosine phosphorylation of Gab-1, whereas expression of a dominant-negative mutant of Csk increased it. Disruption of cell-cell adhesion, which reduced tyrosine phosphorylation of Gab-1, also reduced the activation of mitogen-activated protein kinase and Akt in response to cell-cell adhesion. These results indicate that E-cadherin-mediated cell-cell adhesion induces tyrosine phosphorylation by a Src family kinase of Gab-1, thereby regulating the activation of Ras/MAP kinase and phosphatidylinositol 3-kinase/Akt cascades.


Assuntos
Fosfoproteínas/metabolismo , Tirosina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Caderinas/imunologia , Cálcio/metabolismo , Adesão Celular , Linhagem Celular , Ativação Enzimática , Genes Dominantes , Glutationa Transferase/metabolismo , Immunoblotting , Sistema de Sinalização das MAP Quinases , Camundongos , Mutação , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Plasmídeos/metabolismo , Testes de Precipitina , Ligação Proteica , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas , Proteínas ras/metabolismo
16.
Oncogene ; 19(35): 4022-8, 2000 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-10962558

RESUMO

We have recently found a novel functional unit of cell-cell adhesion at cadherin-based adherens junctions, consisting of at least nectin, an immunoglobulin-like cell adhesion molecule, and afadin, an actin filament-binding protein which connects nectin to the actin cytoskeleton. Among the members of the nectin family, we have found here that nectin-2delta is tyrosine-phosphorylated in response to cell-cell adhesion. Expression of E-cadherin induced tyrosine phosphorylation of nectin-2delta, while disruption of cell-cell adhesion by an anti-E-cadherin antibody reduced the tyrosine phosphorylation of nectin-2delta. An inhibitor specific for Src family kinase or expression of Csk reduced tyrosine phosphorylation of nectin-2delta. In addition, Src kinase tyrosine phosphorylates the recombinant cytoplasmic region of nectin-2delta in vitro. The major tyrosine phosphorylation site of nectin-2delta was Tyr505 in the cytoplasmic region, because the mutant nectin-2delta, of which Tyr505 was replaced by Phe, showed a loss of tyrosine phosphorylation in vivo and in vitro. These results, together with our recent observations, indicate that the cadherin-catenin system and the nectin-afadin system are closely connected to each other. The cadherin-mediated cell-cell adhesion system may link to the activation of a Src family kinase, that is, at least in part, responsible for the tyrosine phosphorylation of the cytoplasmic region of nectin-2delta. Oncogene (2000) 19, 4022 - 4028.


Assuntos
Moléculas de Adesão Celular/metabolismo , Adesão Celular/fisiologia , Processamento de Proteína Pós-Traducional , Proteínas Tirosina Quinases/metabolismo , Junções Íntimas/fisiologia , Quinases da Família src/metabolismo , Animais , Células COS , Caderinas/fisiologia , Linhagem Celular , Meios de Cultura Livres de Soro , Células Epiteliais/metabolismo , Feminino , Humanos , Cinesinas , Neoplasias Mamárias Experimentais/patologia , Camundongos , Proteínas dos Microfilamentos/metabolismo , Miosinas , Nectinas , Fosforilação , Fosfotirosina/biossíntese , Proteínas Recombinantes de Fusão/metabolismo , Transfecção
18.
Mol Biol Cell ; 11(8): 2565-75, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10930454

RESUMO

Hepatocyte growth factor/scatter factor (HGF/SF) induces cell scattering through the tyrosine kinase-type HGF/SF receptor c-Met. We have previously shown that Rho small G protein (Rho) is involved in the HGF/SF-induced scattering of Madin-Darby canine kidney (MDCK) cells by regulating at least the assembly and disassembly of stress fibers and focal adhesions, but it remains unknown how c-Met regulates Rho activity. We have found here a novel signaling pathway of c-Met consisting of SHP-2-Rho that regulates the assembly and disassembly of stress fibers and focal adhesions in MDCK cells. SHP-2 is a protein-tyrosine phosphatase that contains src homology-2 domains. Expression of a dominant negative mutant of SHP-2 (SHP-2-C/S) markedly increased the formation of stress fibers and focal adhesions in MDCK cells and inhibited their scattering. C3, a Clostridium botulinum ADP-ribosyltransferase, and Y-27632, a specific inhibitor for ROCK, reversed the stimulatory effect of SHP-2-C/S on stress fiber formation and the inhibitory effect on cell scattering. Vav2 is a GDP/GTP exchange protein for Rho. Expression of a dominant negative mutant of Vav2 blocked the stimulatory effect of SHP-2-C/S on stress fiber formation. Conversely, expression of mutants of Vav2 that increased stress fiber formation inhibited HGF/SF-induced cell scattering. These results indicate that SHP-2 physiologically modulates the activity of Rho to form stress fibers and focal adhesions and thereby regulates HGF/SF-induced cell scattering. In addition, Vav2 may be involved in the SHP-2-Rho pathway.


Assuntos
Toxinas Botulínicas , Proteínas de Ciclo Celular , Fator de Crescimento de Hepatócito/fisiologia , Proteínas Tirosina Fosfatases/fisiologia , Proteínas rho de Ligação ao GTP/fisiologia , ADP Ribose Transferases/farmacologia , Amidas/farmacologia , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Citoesqueleto/efeitos dos fármacos , Cães , Inibidores Enzimáticos/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular , Microscopia Confocal , Modelos Biológicos , Mutação , Proteínas Serina-Treonina Quinases/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Proteína Tirosina Fosfatase não Receptora Tipo 11 , Proteína Tirosina Fosfatase não Receptora Tipo 6 , Proteínas Tirosina Fosfatases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/fisiologia , Proteínas Proto-Oncogênicas c-vav , Piridinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transfecção , Proteínas rho de Ligação ao GTP/efeitos dos fármacos , Proteínas rho de Ligação ao GTP/metabolismo , Quinases Associadas a rho
19.
Genes Cells ; 5(7): 583-91, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10947844

RESUMO

BACKGROUND: Frabin is an actin filament (F-actin)-binding protein that shows GDP/GTP exchange activity for Cdc42 small G protein (Cdc42). Frabin furthermore induces indirect activation of Rac small G protein (Rac) in intact cells. We have recently shown that in nonepithelial cells, frabin induces the formation of both filopodia- and lamellipodia-like processes through the activation of Cdc42 and Rac, respectively. In epithelial cells such as MDCK cells, Cdc42 and Rac regulate cell-cell adherens junctions (AJs) via the accumulation of F-actin and E-cadherin, although neither Cdc42 nor Rac induces the formation of filopodia or lamellipodia. In this study, we have examined the effects of frabin on the reorganization of the actin cytoskeleton in MDCK cells. RESULTS: Frabin induces the formation of microspikes at the basal area of the lateral membranes through the activation of Cdc42 and Rac in MDCK cells, although a dominant active mutant of Cdc42 or Rac alone, or both, did not induce the formation of microspikes. Furthermore, frabin weakly increased the accumulation of F-actin and E-cadherin at cell-cell AJs and the formation of stress fibres through the activation of Cdc42 and Rac, under conditions where the dominant active mutant of Cdc42 or Rac markedly showed these effects. The Cdc42- and Rac-induced formation of stress fibres was dependent on the activation of Rho small G protein. CONCLUSION: These results indicate that the frabin-dependent spatial activation of Cdc42 and Rac is important for the formation of microspikes.


Assuntos
Actinas/biossíntese , Caderinas/biossíntese , Citoesqueleto/fisiologia , Rim/efeitos dos fármacos , Proteínas dos Microfilamentos/farmacologia , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Células Cultivadas , Expressão Gênica , Genes myc , Proteínas de Fluorescência Verde , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/biossíntese , Imunoglobulina G , Rim/citologia , Rim/metabolismo , Proteínas Luminescentes/biossíntese , Microinjeções , Microscopia de Fluorescência , Fragmentos de Peptídeos/biossíntese , Plasmídeos/biossíntese , Proteínas Recombinantes
20.
J Agric Food Chem ; 48(6): 2189-92, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10888520

RESUMO

Turmeric oil was extracted from turmeric (Curcuma longa) with supercritical carbon dioxide in a semicontinuous-flow extractor. Extraction rate was measured as a function of pressure, temperature, flow rate, and particle size. The extraction rate increased with an increase in CO(2) flow rate and with a reduction of particle size. The effect of pressure and temperature on turmeric extraction suggested the use of higher pressure and lower temperature at which solvent density is greater and thus the solubility of the oil in the solvent is greater in the range of 313-333 K and 20-40 MPa. The major components ( approximately 60%) of the extracted oil were identified as turmerone and ar-turmerone by GC-MS.


Assuntos
Dióxido de Carbono , Extratos Vegetais/isolamento & purificação , Óleos de Plantas/isolamento & purificação , Curcuma , Cromatografia Gasosa-Espectrometria de Massas/métodos , Indicadores e Reagentes , Extratos Vegetais/química
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