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1.
J Nutr Health Aging ; 20(7): 752-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27499309

RESUMO

OBJECTIVES: To describe levels of physical activity among older adults residing at assisted care facilities and their association with physical function. DESIGN: Cross-sectional analysis. SETTING: Assisted care facilities within the greater Boston, MA area. PARTICIPANTS: Older adults aged 65 years and older (N = 65). MEASUREMENTS: Physical Activity Level (PAL) as defined by quartiles from accelerometry (counts and steps), Short Physical Performance Battery (SPPB) Score, gait speed, and handgrip strength. RESULTS: Participants in the most active accelerometry quartile engaged in 25 minutes/week of moderate to vigorous physical activity (MVPA) and walked 2,150 steps/day. These individuals had an SPPB score, 400 meter walk speed, and handgrip strength that was 3.7-3.9 points, 0.3-0.4 meters/second, and 4.5-5.1 kg greater respectively, than individuals in the lowest activity quartile, who engaged in less than 5 min/wk of MVPA or took fewer than 460 steps/day. CONCLUSION: Despite engaging in physical activity levels far below current recommendations (150 min/week of MVPA or > 7000 steps/day), the most active older adults in this study exhibited clinically significant differences in physical function relative to their less active peers. While the direction of causality cannot be determined from this cross-sectional study, these findings suggest a strong association between PAL and physical function among older adults residing in an assisted care facility.


Assuntos
Acelerometria , Exercício Físico/fisiologia , Aptidão Física/fisiologia , Idoso , Idoso de 80 Anos ou mais , Moradias Assistidas , Boston , Estudos Transversais , Feminino , Força da Mão/fisiologia , Humanos , Masculino , Caminhada/fisiologia
2.
Eur J Clin Microbiol Infect Dis ; 33(10): 1663-73, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24828003

RESUMO

Molecular methods such as real-time polymerase chain reaction (PCR) are rapidly replacing traditional tests to detect fecal viral pathogens in childhood diarrhea. This technique has now increased the analytical sensitivity so drastically that positive results are found in asymptomatic children, leading to complex interpretation of real-time PCR results and difficult distinction between asymptomatic shedding and etiological cause of disease. We performed a review of the literature including pediatric studies using real-time PCR and a minimal inclusion period of one year to exclude bias by seasonality. We searched for studies on rotavirus, norovirus, adenovirus, astrovirus, and sapovirus, known to be the most common viruses to cause gastroenteritis in the pediatric population. For these viruses, we summarized the detection rates in hospitalized and community-based children with clinical symptoms of gastroenteritis, as well as subjects with asymptomatic viral shedding. Moreover, insight is given into the different viral sero- and genotypes causing pediatric gastroenteritis. We also discuss the scoring systems for severity of disease and their clinical value. A few published proposals have been made to improve the clinical interpretation of real-time PCR results, which we recapitulate and discuss in this review. We propose using the semi-quantitative measure of real-time PCR, as a surrogate for viral load, in relation to the severity score to distinguish asymptomatic viral shedding from clinically relevant disease. Overall, this review provides a better understanding of the scope of childhood gastroenteritis, discusses a method to enhance the interpretation of real-time PCR results, and proposes conditions for future research to enhance clinical implementation.


Assuntos
Gastroenterite/diagnóstico , Gastroenterite/patologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Viroses/diagnóstico , Viroses/patologia , Vírus/isolamento & purificação , Adolescente , Criança , Pré-Escolar , Interpretação Estatística de Dados , Fezes/virologia , Gastroenterite/virologia , Humanos , Lactente , Recém-Nascido , Técnicas de Diagnóstico Molecular/métodos , Carga Viral , Viroses/virologia , Eliminação de Partículas Virais , Vírus/classificação , Vírus/genética
4.
Curr Urol ; 6(4): 216-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24917747

RESUMO

Paratesticular liposarcoma is a very rare cause of scrotal mass. It is thought that they arise from spermatic cord lipomas most commonly. While well differentiated tumors tend to share many histological similarities with dedifferentiated tumors, the latter has a much more aggressive phenotype. We present an unusual case of a 69-year-old male with synchronous prostate adenocarcinoma and unilateral renal cell carcinoma who was found to have a dedifferentiated paratesticular liposarcoma. Treatment was with radical resection, preserving the testis, followed by radiotherapy. Unusually recurrence did not occur until 4 years following initial treatment. This case demonstrates the high propensity of dedifferentiated liposarcoma to recur locally and examines the most frequently employed management strategies.

5.
Br J Cancer ; 107(8): 1384-91, 2012 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-22968648

RESUMO

BACKGROUND: We tested the accuracy of immunocytochemistry (ICC) for minichromosome maintenance protein-2 (MCM-2) in diagnosing bladder cancer, using cells retrieved from urine. METHODS: Adequate samples were obtained from 497 patients, the majority presenting with gross haematuria (GH) or undergoing cystoscopic surveillance (CS) following previous bladder cancer. We performed an initial study of 313 patients, followed by a validation study of 184 patients. In all cases, presence/absence of bladder cancer was established by cystoscopy/biopsy. RESULTS: In the initial study, receiver operator characteristic analysis showed an area under the curve of 0.820 (P<0.0005) for the GH group and 0.821 (P<0.01) for the CS group. Optimal sensitivity/specificity were provided by threshold values of 50+ MCM-2-positive cells in GH samples and 200+ cells in CS samples, based on a minimum total cell number of 5000. Applying these thresholds to the validation data set gave 81.3% sensitivity, 76.0% specificity and 92.7% negative predictive value (NPV) in GH and 63.2% sensitivity, 89.9% specificity and 89.9% NPV in CS. Minichromosome maintenance protein-2 ICC provided clinically relevant improvements over urine cytology, with greater sensitivity in GH and greater specificity in CS (P=0.05). CONCLUSIONS: Minichromosome maintenance protein-2 ICC is a reproducible and accurate test that is suitable for both GH and CS patient groups.


Assuntos
Biomarcadores Tumorais/urina , Proteínas de Ciclo Celular/urina , Proteínas Nucleares/urina , Neoplasias da Bexiga Urinária/urina , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Feminino , Hematúria , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Componente 2 do Complexo de Manutenção de Minicromossomo , Curva ROC , Neoplasias da Bexiga Urinária/diagnóstico , Adulto Jovem
6.
Ir J Med Sci ; 180(2): 435-7, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21210246

RESUMO

BACKGROUND: On the 1 August 2009, the implementation of European Working Time Directive became European law and was implemented in Galway University Hospital (GUH). AIMS: The aim of the study is to ascertain the opinion of the 25 surgical SHOs in GUH on the effect of the implementation of an EWTD compliant roster had on the quality of their training. METHODS: A questionnaire was circulated to all 25 surgical SHOs. RESULTS: Twenty-two (88%) SHOs report a reduction in the quality of their training. 18 (72%) report a reduction in the development of their operative skills. The SHOs believed the EWTD Rotas would encourage Irish graduates to train abroad. CONCLUSIONS: Surgical training faces a challenge with the implementation of EWTD Rotas. Major changes need to be made to the surgical training structure to train surgeons to the highest standard and to retain Irish-trained surgeons in the Irish healthcare system.


Assuntos
Cirurgia Geral/educação , Internato e Residência/organização & administração , Admissão e Escalonamento de Pessoal/legislação & jurisprudência , Atitude do Pessoal de Saúde , Feminino , Humanos , Irlanda , Masculino , Corpo Clínico Hospitalar/educação , Corpo Clínico Hospitalar/organização & administração , Qualidade da Assistência à Saúde
7.
Ir J Med Sci ; 179(3): 431-3, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19352582

RESUMO

INTRODUCTION: The use of recombinant activated factor VII has been described for many clinical scenarios, but the value of this therapeutic agent for life-threatening haemorrhagic cystitis remains novel. METHOD: We describe a case of persistent life-threatening haemorrhagic radiation cystitis, and discuss current knowledge of this therapy including potential complications. RESULT: Control of haemorrhage was successfully achieved only after use of this agent. CONCLUSION: This therapy deserves mention in any future management algorithm devised for this condition.


Assuntos
Cistite/tratamento farmacológico , Fator VIIa/uso terapêutico , Hemorragia/tratamento farmacológico , Lesões por Radiação/complicações , Adenocarcinoma/radioterapia , Cistite/etiologia , Fator VIIa/administração & dosagem , Evolução Fatal , Hemorragia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/uso terapêutico , Neoplasias Retais/radioterapia , Neoplasias do Colo Sigmoide/radioterapia
8.
Cell Death Differ ; 16(7): 1018-29, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19390558

RESUMO

Glucocorticoids are fundamental drugs used in the treatment of lymphoid malignancies with apoptotic cell death as the hitherto proposed mechanism of action. Recent studies, however, showed that an alternative mode of cell death, autophagy, is involved in the response to anticancer drugs. The specific role of autophagy and its relationship to apoptosis remains, nevertheless, controversial: it can either lead to cell survival or can function in cell death. We show that dexamethasone induced autophagy upstream of apoptosis in acute lymphoblastic leukemia cells. Inhibition of autophagy by siRNA-mediated repression of Beclin 1 expression inhibited apoptosis showing an important role of autophagy in dexamethasone-induced cell death. Dexamethasone treatment caused an upregulation of promyelocytic leukemia protein, PML, its complex formation with protein kinase B or Akt and a PML-dependent Akt dephosphorylation. Initiation of autophagy and the onset of apoptosis were both dependent on these events. PML knockout thymocytes were resistant to dexamethasone-induced death and upregulation of PML correlated with the ability of dexamethasone to kill primary leukemic cells. Our data reveal key mechanisms of dexamethasone-induced cell death that may inform the development of improved treatment protocols for lymphoid malignancies.


Assuntos
Antineoplásicos Hormonais/farmacologia , Apoptose , Autofagia , Dexametasona/farmacologia , Leucemia Linfoide/metabolismo , Adolescente , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Cromonas/farmacologia , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Masculino , Microscopia Eletrônica de Transmissão , Proteínas Associadas aos Microtúbulos/agonistas , Proteínas Associadas aos Microtúbulos/metabolismo , Pessoa de Meia-Idade , Morfolinas/farmacologia , Proteínas Nucleares/agonistas , Proteínas Nucleares/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Proteína da Leucemia Promielocítica , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fatores de Transcrição/agonistas , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/agonistas , Proteínas Supressoras de Tumor/metabolismo
9.
Ir J Med Sci ; 177(1): 75-6, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17605074

RESUMO

BACKGROUND: Carcinosarcoma of the penis is extremely rare and little is known about its biological behaviour. AIMS: We report the second such case and discuss its histological categorisation and biological behaviour. METHODS: A total penectomy with perineal urethrostomy was performed without lymphadenectomy in an 83-year old presenting with a fungating penile mass. RESULTS: Microscopy of the gross specimen showed a biphasic tumour with both squamous and spindle cell elements. Immunohistochemical staining for epithelial markers showed positivity in the squamous cell elements but was uniformly negative in the spindle component. Immunohistochemistry of the spindle cell element demonstrated mesenchymal markers. The patient refused further treatment and follow up but presented at 26 months with inguinal lymphadenopathy. Biopsy confirmed squamous cell carcinoma metastasis consistent with penile origin. The patient refused further surgery and received pelvic irradiation. He died 6 months later. CONCLUSIONS: This case illustrates the biological behaviour of this rare tumour.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/secundário , Neoplasias Penianas/diagnóstico , Neoplasias Penianas/patologia , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Evolução Fatal , Humanos , Masculino , Neoplasias Penianas/cirurgia
11.
Eur J Haematol ; 74(6): 466-80, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15876250

RESUMO

OBJECTIVES: To compare the gene expression pattern in children and adults with acute lymphoblastic leukaemia (ALL) in order to improve our understanding of the difference in disease biology and prognosis. METHODS: The gene expression profiles in diagnostic samples from 29 children and 15 adults with ALL were analysed using the oligonucleotide chip Hu95ver2a, produced by Affymetrix. RESULTS: Unsupervised hierarchical cluster analysis revealed that, in spite of differences in outcome, patients clustered irrespective of age, first by T-cell or B-precursor immunophenotype, and second by cytogenetic changes within the B-precursor group. The expression pattern analysis allowed the reclassification of some samples into the proper cytogenetic group. We also showed that separate clustering of samples with the BCR/ABL translocation could be explained by different breakpoint regions in the BCR. No significant difference in gene expression was observed between samples with and without CDKN2A deletion within the B-precursor group. Analysis of different age groups revealed a similarity in expression profiles when infants with the MLL translocation and adults over 40 yr of age were compared irrespective of karyotype. CONCLUSIONS: In spite of the difference in clinical outcome, the gene expression pattern in children and adults with ALL is very similar and is primarily dependent on immunophenotype and cytogenetic aberrations. However, when age groups are compared, the expression patterns of infants and adults over 40 show a remarkable similarity.


Assuntos
Regulação Leucêmica da Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adulto , Criança , Pré-Escolar , Feminino , Proteínas de Fusão bcr-abl/biossíntese , Proteínas de Fusão bcr-abl/genética , Deleção de Genes , Perfilação da Expressão Gênica , Genes p16 , Humanos , Masculino , Cromossomo Filadélfia
13.
Eur J Cancer ; 38(11): 1466-73, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12110492

RESUMO

Few data are available to help predict which older cancer patient is at risk of developing chemotherapy-related toxicity. This study was a pilot for a project designing a predictive risk score. Chemotherapy patients aged 70 years and older were prospectively enrolled. Chemotherapies were adjusted for their published toxicity. 60 patients were enrolled, 59 were evaluable. Mean dose-intensity was 90.3%, range 33.3-129.0%. 47% of the patients experienced grade 4 haematological and/or grade 3-4 non-haematological toxicity. Published toxicity (MAX2), diastolic blood pressure, marrow invasion and lactate dehydrogenase (LDH) were all associated with toxicity (P<0.1); Body Mass Index, previous chemotherapy, red blood cells, platelets, polymedication with dose-intensity; and polymedication with FACT-G change. After adjustment for the published toxicity, the variables retained their significance, except for LDH and polymedication (for dose-intensity). Although the size of this pilot study imposes a cautious interpretation, patient-related and chemotherapy-related variables correlated independently with toxicity. Designing a composite predictive score to use in assessing the toxicity of multiple chemotherapy regimens therefore appears to be a valid undertaking.


Assuntos
Antineoplásicos/efeitos adversos , Neoplasias/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Avaliação Geriátrica , Humanos , Masculino , Projetos Piloto , Valor Preditivo dos Testes , Estudos Prospectivos
14.
Blood ; 98(8): 2535-43, 2001 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11588052

RESUMO

Radioimmunotherapy with anti-CD20 monoclonal antibodies is a promising new treatment approach for patients with relapsed B-cell lymphomas. However, the majority of patients treated with conventional radiolabeled anti-CD20 antibodies eventually have a relapse because the low tumor-to-blood and tumor-to-normal organ ratios of absorbed radioactivity limit the dose that can be safely administered without hematopoietic stem cell support. This study assessed the ability of a streptavidin-biotin "pretargeting" approach to improve the biodistribution of radioactivity in mice bearing Ramos lymphoma xenografts. A pretargeted streptavidin-conjugated anti-CD20 1F5 antibody was infused, followed 24 hours later by a biotinylated N-acetylgalactosamine-containing "clearing agent" and finally 3 hours later by (111)In-labeled DOTA-biotin. Tumor-to-blood ratios were 3:1 or more with pretargeting, compared with 0.5:1 or less with conventional (111)In-1F5. Tumor-to-normal organ ratios of absorbed radioactivity up to 56:1 were observed with pretargeting, but were 6:1 or less with conventional (111)In-1F5. Therapy experiments demonstrated that 400 microCi (14.8 MBq) or more of conventional (90)Y-1F5 was required to obtain major tumor responses, but this dose was associated with lethal toxicity in 100% of mice. In marked contrast, up to 800 microCi (29.6 MBq) (90)Y-DOTA-biotin could be safely administered by the pretargeting approach with only minor toxicity, and 89% of the mice were cured. These data suggest that anti-CD20 pretargeting shows great promise for improving current therapeutic options for B-cell lymphomas and warrants further preclinical and clinical testing.


Assuntos
Antígenos CD20/imunologia , Radioisótopos do Iodo/uso terapêutico , Linfoma de Células B/radioterapia , Radioimunoterapia/métodos , Animais , Anticorpos Monoclonais/uso terapêutico , Modelos Animais de Doenças , Humanos , Radioisótopos do Iodo/farmacocinética , Camundongos , Camundongos Nus , Taxa de Sobrevida , Distribuição Tecidual , Transplante Heterólogo , Células Tumorais Cultivadas
15.
Genes Chromosomes Cancer ; 32(2): 155-63, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11550283

RESUMO

The 8p11 myeloproliferative syndrome (EMS) is associated with three translocations, t(8;13)(p11;q12), t(8;9)(p11;q33), and t(6;8)(q27;p11), that fuse unrelated genes (ZNF198, CEP110, and FOP, respectively) to the entire tyrosine kinase domain of FGFR1. In all cases thus far examined (n = 10), the t(8;13) results in an identical mRNA fusion between ZNF198 exon 17 and FGFR1 exon 9. To determine if consistent fusions are also seen in the variant translocations, we performed RT-PCR on four cases and sequenced the products. For two patients with a t(8;9), we found that CEP110 exon 15 was fused to FGFR1 exon 9. For two patients with a t(6;8), we found that FOP exon 5 (n = 1) or exon 7 (n = 1) was fused to FGFR1 exon 9. To determine if FGFR1 might be involved in other myeloid disorders with translocations of 8p, we developed a two-color FISH assay using two differentially labeled PAC clones that flank FGFR1. Disruption of this gene was indicated in a patient with a t(8;17)(p11;q25) and Ph-negative chronic myeloid leukemia in association with systemic malignant mast cell disease, a patient with acute myeloid leukemia with a t(8;11)(p11;p15), and two cases with T-cell lymphoma, myeloproliferative disorder, and marrow eosinophilia with a t(8;12)(p11;q15) and ins(12;8)(p11;p11p21), respectively. For the patient with the t(8;11), the chromosome 11 breakpoint was determined to be in the vicinity of NUP98. We conclude that 1) all mRNA fusions in EMS result in splicing to FGFR1 exon 9 but breakpoints in FOP are variable, 2) two-color FISH can identify patients with EMS, and 3) the t(8;17)(p11;q25), t(8;11)(p11;p15), t(8;12)(p11;q15), and ins(12;8)(p11;p11p21) are novel karyotypic changes that most likely involve FGFR1.


Assuntos
Transtornos Mieloproliferativos/genética , Receptores Proteína Tirosina Quinases/genética , Receptores de Fatores de Crescimento de Fibroblastos/genética , Translocação Genética/genética , Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 12/genética , Cromossomos Humanos Par 17/genética , Cromossomos Humanos Par 6/genética , Cromossomos Humanos Par 8/genética , Cromossomos Humanos Par 9/genética , Feminino , Humanos , Hibridização in Situ Fluorescente/métodos , Cariotipagem , Masculino , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Comp Biochem Physiol A Mol Integr Physiol ; 129(4): 897-907, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11440875

RESUMO

The gorgonian coral Leptogorgia virgulata contains thyroxine, or a thyroxine-like substance, referred to here as G-T(4). The G-T(4) levels were significantly higher in colonies collected in the summer vs. winter months. Using immunocytochemical techniques, G-T(4) was localized in the axis, polyp epithelium, and within the electron dense bodies of scleroblasts (spicule-forming cells), as well as on the periphery of spicules. G-T(4) was also localized in the mesoglea between closely adjacent scleroblasts. The effects of exogenous T(4) on the uptake of Ca(45) was determined in spicule, tissue and axis fractions of L. virgulata. The uptake of Ca(45) increased in T(4) treated spicules but decreased in the tissue fraction for all time periods tested. The uptake of Ca(45) into axes was not affected by exogenous T(4) until day 10 of the study. These data suggest that G-T(4) may function in the process of spicule formation. 1,25-dihydroxyvitamin D apparently is synthesized via ultraviolet radiation. Colonies deprived of ultraviolet radiation had significantly more 'irregular' spicules than colonies maintained in ultraviolet radiation. Exposure to sunlight therefore may be associated with the process of normal spicule formation.


Assuntos
Cnidários/metabolismo , Tiroxina/metabolismo , Vitamina D/análogos & derivados , Vitamina D/metabolismo , Animais , Cálcio/metabolismo , Cnidários/ultraestrutura , Imuno-Histoquímica , Estações do Ano , Tiroxina/farmacologia , Raios Ultravioleta
17.
Eur J Neurosci ; 13(8): 1501-19, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11328345

RESUMO

The perirhinal cortex has recently been implicated in the kindling of limbic generalized seizures. The following experiments in rats tested the selectivity of the perirhinal cortex's epileptogenic properties by comparing its kindling profile with those of the adjacent insular cortex, posterior (dorsolateral) claustrum and amygdala. The first experiment examined the kindling and EEG profiles, and found that both the claustrum and insular cortex demonstrated rapid epileptogenic properties similar to the perirhinal cortex, including very rapid kindling rates and short latencies to convulsion. Furthermore, electrical stimulation of all three structures led to a two-phase progression through stage-5 seizures which had characteristics of both neocortical and amygdaloid kindling. In a second experiment rats were suspended in a harness to allow for more detailed documentation of both forelimb and hindlimb convulsions. With this procedure we were able to detect subtle yet unique differences in convulsion characteristics from each of the kindled sites and stage-5 seizure phases. Some of these convulsive parameters were correlated with changes in FosB/DeltaFosB protein and BDNF mRNA expression measured two hours after the last convulsion. Overall, it appears that the perirhinal cortex is not unique in its property of rapid epileptogenesis. Moreover, the posterior claustrum exhibited the fastest kindling and most vigorous patterns of clonus, suggesting that it may be even more intimately associated with the motor substrates responsible for limbic seizure generalization than is the perirhinal cortex.


Assuntos
Gânglios da Base/fisiologia , Córtex Cerebral/fisiologia , Córtex Entorrinal/fisiologia , Excitação Neurológica , Proteínas Proto-Oncogênicas c-fos , Fatores de Transcrição , Animais , Proteínas de Bactérias/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Limiar Diferencial , Eletroencefalografia , Eletrofisiologia , Membro Anterior/fisiopatologia , Membro Posterior/fisiopatologia , Masculino , Ratos , Ratos Long-Evans , Convulsões/fisiopatologia
18.
J Biol Chem ; 276(5): 3203-14, 2001 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-11042184

RESUMO

The tissue inhibitors of metalloproteinases (TIMPs) block matrix metalloproteinase (MMP)-mediated increases in cell proliferation, migration, and invasion that are associated with extracellular matrix (ECM) turnover. Here we demonstrate a direct role for TIMP-2 in regulating tyrosine kinase-type growth factor receptor activation. We show that TIMP-2 suppresses the mitogenic response to tyrosine kinase-type receptor growth factors in a fashion that is independent of MMP inhibition. The TIMP-2 suppression of mitogenesis is reversed by the adenylate cyclase inhibitor SQ22536, and implicates cAMP as the second messenger in these effects. TIMP-2 neither altered the release of transforming growth factor alpha from the cell surface, nor epidermal growth factor (EGF) binding to the cognate receptor, EGFR. TIMP-2 binds to the surface of A549 cells in a specific and saturable fashion (K(d) = 147 pm), that is not competed by the synthetic MMP inhibitor BB-94 and is independent of MT-1-MMP. TIMP-2 induces a decrease in phosphorylation of EGFR and a concomitant reduction in Grb-2 association. TIMP-2 prevents SH2-protein-tyrosine phosphatase-1 (SHP-1) dissociation from immunoprecipitable EGFR complex and a selective increase in total SHP-1 activity. These studies represent a new functional paradigm for TIMP-2 in which TIMP suppresses EGF-mediated mitogenic signaling by short-circuiting EGFR activation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Inibidores de Metaloproteinases de Matriz , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Inibidor Tecidual de Metaloproteinase-2/farmacologia , Adenilil Ciclases/metabolismo , Divisão Celular/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ativação Enzimática , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Proteína Adaptadora GRB2 , Humanos , Metaloproteinase 1 da Matriz/metabolismo , Fosforilação , Proteína Fosfatase 1 , Proteínas Tirosina Fosfatases/metabolismo , Proteínas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais/fisiologia , Células Tumorais Cultivadas
19.
J Pathol ; 192(4): 455-9, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11113862

RESUMO

Genetic changes occurring in the late stages of colonic tumour progression have received much less attention than those occurring in the early stages. As described in the accompanying paper, SW480 and SW620 cell lines provide a useful model for studying the advanced stages of progression for colon cancer. Comparison of the two cell lines by differential display reveals that SW620 cells express lower levels of the CC3 tumour suppressor gene and also lower levels of the tissue inhibitor of metalloproteinases-3 (TIMP-3) gene. Northern blot analysis for TIMP-3 confirms this finding and shows a similar difference in the expression of TIMP-2, which seems logical since TIMPs inhibit enzymes that play a role in tumour invasion. For this reason, it was surprising to find that TIMP-1 messenger RNA expression is markedly increased in SW620 cells. Consistent with this finding, western blot analysis shows a ten-fold increase in TIMP-1 protein secretion by SW620 cells. It is noteworthy that high TIMP-1 expression is associated with poor prognosis in colorectal cancer. This association between TIMP-1 expression and tumour progression may be related to additional growth factor-like effects described for TIMP-1 in some systems.


Assuntos
Neoplasias do Colo/metabolismo , Proteínas de Neoplasias/metabolismo , Inibidores de Proteases/metabolismo , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Northern Blotting , Western Blotting , Neoplasias do Colo/patologia , Progressão da Doença , Expressão Gênica , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Inibidor Tecidual de Metaloproteinase-1/genética , Inibidor Tecidual de Metaloproteinase-2/genética , Inibidor Tecidual de Metaloproteinase-2/metabolismo , Inibidor Tecidual de Metaloproteinase-3/genética , Inibidor Tecidual de Metaloproteinase-3/metabolismo , Células Tumorais Cultivadas
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