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1.
Int J Popul Data Sci ; 4(2): 1140, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34095542

RESUMO

The Centre for Data and Knowledge Integration for Health (CIDACS) was created in 2016 in Salvador, Bahia-Brazil with the objective of integrating data and knowledge aiming to answer scientific questions related to the health of the Brazilian population. This article details our experiences in the establishment and operations of CIDACS, as well as efforts made to obtain high-quality linked data while adhering to security, ethical use and privacy issues. Every effort has been made to conduct operations while implementing appropriate structures, procedures, processes and controls over the original and integrated databases in order to provide adequate datasets to answer relevant research questions. Looking forward, CIDACS is expected to be an important resource for researchers and policymakers interested in enhancing the evidence base pertaining to different aspects of health, in particular when investigating, from a nation-wide perspective, the role of social determinants of health and the effects of social and environmental policies on different health outcomes.

2.
Sci Rep ; 7(1): 16755, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29196692

RESUMO

Decompression times reported in previous studies suggest that thoroughly brittle fragmentation is unlikely in actual explosive volcanic eruptions. What occurs in practice is brittle-like fragmentation, which is defined as the solid-like fracture of a material whose bulk rheological properties are close to those of a fluid. Through laboratory experiments and numerical simulation, the link between the inhomogeneous structure of bubbles and the development of cracks that may lead to brittle-like fragmentation was clearly demonstrated here. A rapid decompression test was conducted to simulate the fragmentation of a specimen whose pore morphology was revealed by X-ray microtomography. The dynamic response during decompression was observed by high-speed photography. Large variation was observed in the responses of the specimens even among specimens with equal bulk rheological properties. The stress fields of the specimens under decompression computed by finite element analysis shows that the presence of satellite bubbles beneath a large bubble induced the stress concentration. On the basis of the obtained results, a new mechanism for brittle-like fragmentation is proposed. In the proposed scenario, the second nucleation of bubbles near the fragmentation surface is an essential process for the advancement of fragmentation in an upward magma flow in a volcanic conduit.

3.
Free Radic Res ; 48(4): 427-34, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24437351

RESUMO

Reactive oxygen species (ROS) play a key role in neoplastic growth and tumor invasion is supported by various experimental data. In this study, we analyzed the participation of ROS in the RET tyrosine auto-phosphorylation. The NIH3T3 cell lines transfected with cRET, MEN2A, and MEN2B individually (designated NIH3T3cRET, NIH3T3 RET-MEN2A, and NIH3T3RET-MEN2B) showed the elevated levels of intracellular ROS, and concomitantly increased Rac1 expression, as well as down-regulation of Mn SOD and Cu/Zn SOD in comparison with the parental cell line expressing RET. H2O2 enhanced the constitutive tyrosine auto-phosphorylation of RET-MEN2A and RET-MEN2B proteins, and this increase was attenuated by treatment with the NOX inhibitor diphenyliodonium (DPI) or catalase. We also showed that DPI inhibited dimerization of RET-MEN2A. Elevated ROS derived from NOX1 activation and downregulation of SOD in NIH3T3RET-MEN2A and NIH3T3RET-MEN 2B cells may be involved in RET constitutive tyrosine auto-phosphorylation, and scavengers of ROS such as catalase and blocking NOX1 are useful for targeting RET tyrosine kinase activation in cancer.


Assuntos
NADH NADPH Oxirredutases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Proliferação de Células , Humanos , Camundongos , NADH NADPH Oxirredutases/genética , NADPH Oxidase 1 , Fosforilação , Receptores Proteína Tirosina Quinases/genética , Transdução de Sinais
4.
Biochim Biophys Acta ; 1833(5): 1006-16, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23328083

RESUMO

Sphingosine kinase 1 (SPHK1) overexpression in malignant cells has been reported. Mouse Friend cells showed higher SPHK1 but not SPHK2 expression compared with other mouse cell lines. A Sphk1 promoter analysis demonstrated the region between -53bp and the first exon as the minimal promoter. Further promoter truncation revealed the importance of a MYB-binding site. EMSA using this region as the probe demonstrated one band containing c-MYB protein, and its intensity decreased during erythroid differentiation with hexamethylane bisacetamide (HMBA), a potent inducer of erythroid differentiation of Friend cells. ChIP assay also revealed in vivo binding of c-MYB. c-MYB overexpression and siRNA for c-Myb affected SPHK1 expression, confirming the important regulatory role of c-MYB in SPHK1 expression. HMBA reduced c-MYB expression rapidly. Induced differentiation by HMBA caused a marked and rapid reduction of SPHK1 mRNA, protein and enzyme activity leading to the rapid decrease of cellular sphingosine 1-phosphate level. Moreover, terminally differentiated cells did not resume SPHK1 expression. Compared with original Friend cells, stable overexpression of wild-type SPHK1 showed higher cell proliferation, resistance to cell death by serum depletion. Interestingly, HMBA-induced differentiation of these cells was delayed but not completely suppressed. In contrast, SPHK inhibitor and its siRNA inhibited cell growth and enhanced HMBA-induced differentiation significantly, suggesting that SPHK1 delayed HMBA-induced differentiation by its cell proliferation-promoting activity. Effects of pertussis toxin, a G-protein-coupled receptor inhibitor, and S1P receptor antagonist on Friend cell growth and differentiation were negligible, suggesting the importance of the intracellular SPHK1/S1P signaling in Friend cells.


Assuntos
Diferenciação Celular/genética , Fosfotransferases (Aceptor do Grupo Álcool) , Proteínas Proto-Oncogênicas c-myb , Receptores de Lisoesfingolipídeo , Animais , Linhagem Celular , Regulação para Baixo , Humanos , Camundongos , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno , Receptores de Lisoesfingolipídeo/antagonistas & inibidores , Receptores de Lisoesfingolipídeo/genética , Receptores de Lisoesfingolipídeo/metabolismo , Transdução de Sinais
5.
J Microsc ; 238(3): 200-9, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20579258

RESUMO

This paper reports a procedure to combine the focused ion beam micro-sampling method with conventional Ar-milling to prepare high-quality site-specific transmission electron microscopy cross-section samples. The advantage is to enable chemical and structural evaluations of oxygen dissolved in a molten iron sample to be made after quenching and recovery from high-pressure experiments in a laser-heated diamond anvil cell. The evaluations were performed by using electron energy-loss spectroscopy and high-resolution transmission electron microscopy. The high signal to noise ratios of electron energy-loss spectroscopy core-loss spectra from the transmission electron microscopy thin foil, re-thinned down to 40 nm in thickness by conventional Argon ion milling, provided us with oxygen quantitative analyses of the quenched molten iron phase. In addition, we could obtain lattice-fringe images using high-resolution transmission electron microscopy. The electron energy-loss spectroscopy analysis of oxygen in Fe(0.94)O has been carried out with a relative accuracy of 2%, using an analytical procedure proposed for foils thinner than 80 nm. Oxygen K-edge energy-loss near-edge structure also allows us to identify the specific phase that results from quenching and its electronic structure by the technique of fingerprinting of the spectrum with reference spectra in the Fe-O system.

6.
Clin Neuropathol ; 28(2): 105-12, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19353842

RESUMO

Intestinal ganglioneuromatosis (GN) is an uncommon disease of the enteric nervous system (ENS) and its pathogenesis remains unclear. Here we describe a unique case of diffuse GN of the intestinal wall associated with colon adenocarcinoma occurring in a 38-year-old female. Because it is well-known that glial cell line-derived neurotrophic factor (GDNF) and its receptor components, GDNF family receptor-alpha 1 (GFR-alpha 1) and RET receptor tyrosine kinase, play a crucial role in the development of ENS, their expression was analyzed by immunohistochemistry. Interestingly, GDNF as well as a related neurotrophic factor, neurturin (NTN), were expressed at high levels in adenocarcinoma cells whereas expression of GFR alpha 1 and RET was undetectable in them. In contrast, GFR-alpha 1 showed positive staining in both proliferating ganglion cells and glial cells, and RET immunoreactivity was found mainly in ganglion cell bodies. These findings suggested that GDNF and NTN expression in adenocarcinoma cells may play an important role in the pathogenesis of GN.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Sistema Nervoso Entérico/patologia , Ganglioneuroma/patologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Neurturina/metabolismo , Adenocarcinoma/patologia , Adulto , Proliferação de Células , Colo/metabolismo , Colo/patologia , Sistema Nervoso Entérico/metabolismo , Feminino , Ganglioneuroma/metabolismo , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Imuno-Histoquímica , Neuroglia/fisiologia , Proteínas Proto-Oncogênicas c-ret/metabolismo , Proteínas S100/metabolismo
7.
Oncogene ; 27(43): 5684-95, 2008 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-18542059

RESUMO

Germline mutations in the RET tyrosine kinase gene are responsible for the development of multiple endocrine neoplasia 2A and 2B (MEN2A and MEN2B). However, knowledge of the fundamental principles that determine the mutant RET-mediated signaling remains elusive. Here, we report increased expression of mitogen-activated protein kinase phosphatase-2 (MKP-2) in carcinomas developed in transgenic mice carrying RET with the MEN2A mutation (RET-MEN2A). The expression of MKP-2 was not only induced by RET-MEN2A or RET-MEN2B mutant proteins but also by the activation of endogenous RET by its ligand, glial cell line-derived neurotrophic factor (GDNF). MKP-2 expression was also evident in the MKK-f cell line, which was established from a mammary tumor developed in a RET-MEN2A transgenic mouse. Inhibition of MKP-2 attenuated the in vitro and in vivo proliferation of MKK-f cells, which was mediated by the suppression of cyclin B1 expression. Furthermore, we found that MKP-2 is highly expressed in medullary thyroid carcinomas derived from MEN2A patients. These findings suggest that the increased expression of MKP-2 may play a crucial role in oncogenic signaling downstream of mutant RET, leading to deregulation of cell cycle.


Assuntos
Neoplasia Endócrina Múltipla Tipo 2a/genética , Neoplasias Experimentais/etiologia , Proteínas Tirosina Fosfatases/fisiologia , Proteínas Proto-Oncogênicas c-ret/fisiologia , Animais , Divisão Celular , Linhagem Celular Tumoral , Proliferação de Células , Ciclina B/antagonistas & inibidores , Ciclina B1 , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Fase G2 , Camundongos , Camundongos Transgênicos , Fosforilação , Proteínas Tirosina Fosfatases/genética
8.
Ultrasound Obstet Gynecol ; 30(1): 47-51, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17492825

RESUMO

OBJECTIVES: To investigate the application of high-intensity focused ultrasound (HIFU) for fetal umbilical artery blood flow occlusion in a rabbit model. METHODS: A prototype HIFU transducer in combination with an imaging probe with Doppler capability was constructed. Using this transducer, HIFU was applied at 1.4, 2.75 or 5.5 kW/cm(2) through the maternal abdominal skin to the fetal intra-abdominal umbilical arteries of four time-mated Japanese White rabbits (11 fetuses) on gestational day 25. Courses of 5-s HIFU exposure were performed until cessation of umbilical blood flow and cardiac arrest were confirmed by Doppler ultrasonography. Fetal necropsy was performed and exposed lesions were assessed by microscopic histological analysis. RESULTS: The mean diameter of the fetal umbilical artery was 0.6 +/- 0.2 mm and the mean peak systolic velocity of arterial blood flow was 44.7 +/- 18.5 cm/s. When HIFU was applied at 5.5 kW/cm(2), blood flow was completely occluded within 15 courses. HIFU exposure brought about vacuolar degeneration and destruction of elastic fibers in the tunica media of the artery. CONCLUSIONS: HIFU can be used to occlude umbilical artery blood flow in fetal rabbits.


Assuntos
Arteriopatias Oclusivas/diagnóstico por imagem , Terapia por Ultrassom/métodos , Ultrassonografia Pré-Natal/métodos , Artérias Umbilicais/diagnóstico por imagem , Animais , Arteriopatias Oclusivas/terapia , Velocidade do Fluxo Sanguíneo/fisiologia , Feminino , Modelos Animais , Gravidez , Coelhos , Ratos , Artérias Umbilicais/fisiopatologia
9.
Int J Tuberc Lung Dis ; 9(10): 1171-3, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16229231

RESUMO

Bacille Calmette-Guérin (BCG) efficacy against pulmonary disease is highly variable; until very recently there was no evidence of protection after 10 years. In the control arm of a trial of efficacy of revaccination of schoolchildren in Brazil we found substantial protection (39%; 95%CI 9-58) of neonatal BCG against all forms of tuberculosis (TB) 15-20 years after vaccination, much longer than previously believed. This confirms recent findings from an earlier trial, and must be considered in the design of trials of new TB vaccines and in policy decisions based on assumed lack of neonatal BCG protection with time.


Assuntos
Vacina BCG/administração & dosagem , Tuberculose Pulmonar/prevenção & controle , Adolescente , Brasil/epidemiologia , Criança , Humanos , Recém-Nascido , Fatores de Tempo , Tuberculose Pulmonar/epidemiologia
10.
Neuroscience ; 121(4): 899-906, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14580940

RESUMO

Glial cell line-derived neurotrophic factor (GDNF) signals through multisubunit receptor complex consisting of RET tyrosine kinase and a glycosylphosphatidylinositol-anchored coreceptor called GDNF family receptor alpha1 (GFRalpha1). In the current study, we cloned a human SEP1 gene as a GDNF-inducible gene using human neuroblastoma cells that express RET and GFRalpha1. The induction of the SEP1 gene showed two peaks at 0.5-2 h and 24-48 h after GDNF stimulation by Northern blotting and quantitative real-time reverse transcriptase polymerase chain reaction. The late induction was also confirmed at protein levels by Western blotting with anti-SEP1 antibody. Immunostaining revealed that the expression of the SEP1 protein was detected in cell body, elongated neurites and growth cone-like structure of neuroblastoma cells treated with GDNF. In addition, we found a high level of SEP1 expression in neurons of the dorsal root and superior cervical ganglia and motor neurons of the spinal cord of mice in which RET is also expressed. SEP1 was co-immunoprecipitated with alpha- and beta-tubulins from the lysate of mouse brain. These results thus suggested that SEP1 is a GDNF-inducible and microtubule-associated protein that may play a role in the nervous system.


Assuntos
Exorribonucleases/genética , Proteínas Associadas aos Microtúbulos/genética , Fatores de Crescimento Neural/metabolismo , Sistema Nervoso/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Animais , Anticorpos/farmacologia , Linhagem Celular , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Exorribonucleases/biossíntese , Exorribonucleases/isolamento & purificação , Imunofluorescência , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Fator Neurotrófico Derivado de Linhagem de Célula Glial , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/biossíntese , Proteínas Associadas aos Microtúbulos/isolamento & purificação , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Dados de Sequência Molecular , Fatores de Crescimento Neural/farmacologia , Sistema Nervoso/efeitos dos fármacos , Neuroblastoma , Neurônios/citologia , Neurônios/metabolismo , Especificidade de Órgãos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-ret , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Tubulina (Proteína)/metabolismo
11.
Int J Tuberc Lung Dis ; 7(4): 399-402, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12729348

RESUMO

OBJECTIVE: To evaluate the incidence of adverse reactions to first and second bacille Calmette-Guérin (BCG) vaccination in schoolchildren. SETTING AND DESIGN: Enhanced surveillance in a Brazilian trial. Suspected reactions were reported to a nurse who visited cases and completed a standard form. RESULTS: Among 71341 schoolchildren studied, 33 reactions were reported. Of these, 25 fulfilled the criteria, resulting in a rate of one per 2854 vaccinations, with no deaths or BCG-osis. Reactions to second doses were more common than to first BCG vaccinations, but this difference was not statistically significant. CONCLUSIONS: Adverse reactions to a second dose of BCG may be more frequent than reactions to a first dose, but they are still rare events.


Assuntos
Vacina BCG/efeitos adversos , Vacinação em Massa/efeitos adversos , Tuberculose Pulmonar/prevenção & controle , Adolescente , Vacina BCG/administração & dosagem , Brasil/epidemiologia , Criança , Estudos de Coortes , Relação Dose-Resposta a Droga , Eritema/induzido quimicamente , Eritema/epidemiologia , Feminino , Febre/induzido quimicamente , Febre/epidemiologia , Humanos , Hipersensibilidade Imediata/induzido quimicamente , Hipersensibilidade Imediata/epidemiologia , Esquemas de Imunização , Linfadenite/induzido quimicamente , Linfadenite/epidemiologia , Masculino , Prevalência , Prognóstico , Sistema de Registros , Medição de Risco , Úlcera Cutânea/induzido quimicamente , Úlcera Cutânea/epidemiologia , Estudantes
12.
Int J Clin Pract ; 56(9): 721-2, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12469991

RESUMO

A 65-year-old man was admitted to our hospital with acute myocardial infarction (MI). Emergency coronary angiography showed no significant organic lesions, but a myocardial bridge was found at the mid-left anterior descending artery An acetylcholine provocation test revealed 90% spastic stenosis just proximal to the myocardial bridge. His acute MI could have been caused by both a coronary spasm and the myocardial bridge.


Assuntos
Vasoespasmo Coronário/complicações , Anomalias dos Vasos Coronários/complicações , Infarto do Miocárdio/etiologia , Acetilcolina , Idoso , Angiografia Coronária , Vasoespasmo Coronário/diagnóstico por imagem , Anomalias dos Vasos Coronários/diagnóstico por imagem , Humanos , Masculino , Infarto do Miocárdio/diagnóstico por imagem
13.
J Biol Chem ; 276(38): 35644-51, 2001 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-11485998

RESUMO

Most mutations after DNA damage in yeast Saccharomyces cerevisiae are induced by error-prone translesion DNA synthesis employing scRev1 and DNA polymerase zeta that consists of scRev3 and scRev7 proteins. Recently, the human REV1 (hREV1) and REV3 (hREV3) genes were identified, and their products were revealed to be involved in UV-induced mutagenesis, as observed for their yeast counterparts. Human REV7 (hREV7) was also cloned, and its product was found to interact with hREV3, but the biological function of hREV7 remained unknown. We report here the analyses of precise interactions in the human REV proteins. The interaction between hREV1 and hREV7 was identified by the yeast two-hybrid library screening using a bait of hREV7, which was confirmed by in vitro and in vivo binding assays. The homodimerization of hREV7 was also detected in the two-hybrid analysis. In addition, the precise domains for interaction between hREV7 and hREV1 or hREV3 and for hREV7 homodimerization were determined. Although hREV7 interacts with both hREV1 and hREV3, a stable complex formation of the three proteins was undetectable in vitro. These findings suggest the possibility that hREV7 might play an important role in regulating the enzymatic activities of hREV1 and hREV3 for mutagenesis in response to DNA damage.


Assuntos
Proteínas de Transporte/metabolismo , Reparo do DNA , DNA Polimerase Dirigida por DNA/metabolismo , Nucleotidiltransferases/metabolismo , Proteínas , Proteínas de Transporte/fisiologia , Clonagem Molecular , Dano ao DNA/fisiologia , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA , DNA Polimerase Dirigida por DNA/fisiologia , Dimerização , Células HeLa , Humanos , Proteínas Mad2 , Dados de Sequência Molecular , Mutagênese , Proteínas Nucleares , Nucleotidiltransferases/genética , Nucleotidiltransferases/fisiologia , Saccharomyces cerevisiae/metabolismo , Técnicas do Sistema de Duplo-Híbrido
14.
Gastroenterology ; 121(1): 24-33, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11438491

RESUMO

BACKGROUND AND AIMS: Many missense mutations in the RET proto-oncogene were found in familial and sporadic cases of Hirschsprung disease (HSCR). The aim of this study was to make clear the mechanisms of RET dysfunction by HSCR mutations identified in its kinase domain. METHODS: Ten kinase domain HSCR mutations were introduced into wild-type RET and constitutively activated RET with a multiple endocrine neoplasia 2A mutation, and the resulting mutant complementary DNAs were transfected into SK-N-MC primitive neuroectodermal tumor cells or NIH 3T3 fibroblast cells. The levels of activation of mutant RET and representative signaling molecules were investigated in the transfectants. RESULTS: E762Q, S767R, R972G, and M980T mutations partially impaired the RET kinase activity and the representative signaling pathways. In particular, these mutations severely impaired the phospholipase C-gamma signaling pathway in SK-N-MC cells. S765P, R873Q, F893L, R897Q, and E921K mutations resulted in a complete loss of the RET kinase activity. The P973L mutation markedly decreased the expression of the RET protein with normal kinase activity. CONCLUSIONS: Hirschsprung disease can result from these distant functional classes of kinase domain mutation of RET.


Assuntos
DNA Complementar/genética , Proteínas de Drosophila , Doença de Hirschsprung/genética , Proteínas Quinases/genética , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Células Cultivadas , Mutação em Linhagem Germinativa , Humanos , Mutação de Sentido Incorreto , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-ret , Transdução de Sinais , Transfecção
15.
Org Lett ; 3(2): 255-7, 2001 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-11430048

RESUMO

[figure: see text] A 6-O-o-nitrobenzyl methylglucoside and methylmannoside were synthesized by reacting 4,6-O-o-nitrobenzylidene acetals with triethylsilane and boron trifluoride etherate. A 2,6-di-O-o-nitrobenzyl and a 3,6-di-O-o-nitrobenzyl methylmannoside were obtained from a 2,3:4,6-di-O-o-nitrobenzylidene methylmannoside by the same method. The photolabile sugars obtained were deprotected by irradiation at 350 nm to afford methylglycosides.


Assuntos
Compostos de Benzilideno/química , Compostos de Benzilideno/síntese química , Monossacarídeos/química , Monossacarídeos/síntese química , Compostos de Benzilideno/efeitos da radiação , Modelos Moleculares , Conformação Molecular , Monossacarídeos/efeitos da radiação , Fotólise , Relação Estrutura-Atividade
16.
Br J Haematol ; 111(2): 656-8, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11122117

RESUMO

The development of myelodysplastic syndrome/acute myeloblastic leukaemia (MDS/AML) has been reported in patients with aplastic anaemia (AA) after administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF). Similarly, patients with severe congenital neutropenia (SCN) have an increased risk of developing MDS/AML after treatment with rhG-CSF. Point mutations in the G-CSF receptor gene are found in about 20% of SCN patients who are predisposed to MDS/AML. We investigated the occurrence of mutations in the G-CSF receptor in eight patients with AA who developed MDS/AML. No mutations were detected around the cytoplasmic domain of the gene in our patients, indicating that the mechanisms of clonal evolution to MDS/AML in patients with AA might be different from those with SCN.


Assuntos
Anemia Aplástica/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Imunossupressores/uso terapêutico , Leucemia Mieloide Aguda/etiologia , Síndromes Mielodisplásicas/etiologia , Receptores de Fator Estimulador de Colônias de Granulócitos/genética , Adulto , Criança , Pré-Escolar , Humanos , Masculino , Mutação Puntual , Polimorfismo Conformacional de Fita Simples , Proteínas Recombinantes
17.
Neuroscience ; 100(4): 841-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11036218

RESUMO

Expression of glycoprotein 130 and the related receptors, including interleukin-6 receptor and leukemia inhibitory factor receptor, was examined in the murine cerebellum at the protein level. Western blot analysis revealed that interleukin-6 receptor, leukemia inhibitory factor receptor and glycoprotein 130 were expressed in the murine cerebellum. Immunoreactivities for interleukin-6 receptor, leukemia inhibitory factor receptor and glycoprotein 130 were strongly localized on the cell body of Purkinje cells, indicating that both interleukin-6 and leukemia inhibitory factor could act directly on Purkinje cells in murine adult mice. The expressions of interleukin-6 receptor, leukemia inhibitory factor receptor and glycoprotein 130 were observed on the cell membranes of Purkinje cells by immunoelectron microscopy. Immunoreactivity for the interleukin-6 receptor was also detected in the cytoplasm of Purkinje cells. Injection of a murine hemopoietic cell line, FDC-P1 cells, transfected with the complementary DNA encoding the leukemia inhibitory factor led to a reduction in calbindin-positive dendrites of the Purkinje cells.The present results suggest that the leukemia inhibitory factor affects cerebellar functions through Purkinje cells.


Assuntos
Cerebelo/metabolismo , Inibidores do Crescimento/metabolismo , Interleucina-6 , Linfocinas/metabolismo , Glicoproteínas de Membrana/metabolismo , Células de Purkinje/patologia , Receptores de Citocinas/metabolismo , Receptores de Interleucina-6/metabolismo , Animais , Western Blotting , Linhagem Celular , Transplante de Células , Cerebelo/patologia , Dendritos/patologia , Imuno-Histoquímica , Fator Inibidor de Leucemia , Subunidade alfa de Receptor de Fator Inibidor de Leucemia , Proteínas de Membrana Lisossomal , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Microscopia Imunoeletrônica , Células de Purkinje/ultraestrutura , Receptores de OSM-LIF
18.
Oncogene ; 19(39): 4469-75, 2000 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-11002419

RESUMO

Glial cell line derived neurotrophic factor (GDNF) signals through a multicomponent receptor complex consisting of RET receptor tyrosine kinase and a member of GDNF family receptor alpha (GFRalpha). Recently, it was shown that tyrosine 1062 in RET represents a binding site for SHC adaptor proteins and is crucial for both RAS/mitogen activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3-K)/AKT signaling pathways. In the present study, we characterized how these two pathways diverge from tyrosine 1062, using human neuroblastoma and primitive neuroectodermal tumor cell lines expressing RET at high levels. In response to GDNF stimulation, SHC bound to GAB1 and GRB2 adaptor proteins as well as RET, and SHC and GAB1 were highly phosphorylated on tyrosine. The complex formation consisting of SHC, GAB1 and GRB2 was almost abolished by replacement of tyrosine 1062 in RET with phenylalanine. Tyrosine-phosphorylated GAB1 was also associated with p85 subunit of PI3-K, resulting in PI3-K and AKT activation, whereas SHC-GRB2-SOS complex was responsible for the RAS/ERK signaling pathway. These results suggested that the RAS and PI3-K pathways activated by GDNF bifurcate mainly through SHC bound to tyrosine 1062 in RET. Furthermore, using luciferase reporter-gene assays, we found that the RAS/ERK and PI3-K signaling pathways are important for activation of CREB and NF-kappaB in GDNF-treated cells, respectively. Oncogene (2000) 19, 4469 - 4475.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas Adaptadoras de Transporte Vesicular , Proteínas de Drosophila , Fatores de Crescimento Neural , Proteínas do Tecido Nervoso/farmacologia , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais , Androstadienos/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Proteína Adaptadora GRB2 , Fator Neurotrófico Derivado de Linhagem de Célula Glial , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial , Humanos , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , NF-kappa B/efeitos dos fármacos , NF-kappa B/genética , NF-kappa B/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/metabolismo , Fosforilação , Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas c-ret , Proteínas Adaptadoras da Sinalização Shc , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Células Tumorais Cultivadas , Tirosina/metabolismo , Wortmanina , Proteínas ras/metabolismo
19.
Biochem Biophys Res Commun ; 268(3): 804-8, 2000 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-10679286

RESUMO

Multiple endocrine neoplasia (MEN) type 2B mutations have been reported at methionine 918 or alanine 883 in the tyrosine kinase domain of the RET proto-oncogene. Recently, a new combination of two germline missense mutations at valine 804 and tyrosine 806 was identified in a patient with MEN 2B-like clinical phenotypes including medullary thyroid carcinoma, mucosal neuroma, and marfanoid habitus. In this case, valine 804 and tyrosine 806 were replaced with methionine and cysteine, respectively. In the present study, biological activities of RET with these new mutations were compared with those with known MEN 2A or MEN 2B mutations. The transforming activity of RET with the V804M/Y806C mutation was about 8- to 13-fold higher than that of RET with a single V804M or Y806C mutation. Like RET with the M918T or A883F MEN 2B mutation, the transforming activity of RET with the V804M/Y806C mutation was not affected by substitution of phenylalanine for tyrosine 905 that abolished the activity of RET with the MEN 2A mutation. On the other hand, substitution of phenylalanine for tyrosines 864 and 952 drastically diminished the activity of RET with the V804M/Y806C, M918T or A883F mutation, suggesting that these three mutant proteins have similar biological properties.


Assuntos
Proteínas de Drosophila , Mutação em Linhagem Germinativa , Modelos Genéticos , Neoplasia Endócrina Múltipla Tipo 2b/genética , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes , Receptores Proteína Tirosina Quinases/genética , Células 3T3 , Adulto , Substituição de Aminoácidos , Animais , Feminino , Humanos , Masculino , Camundongos , Neoplasia Endócrina Múltipla Tipo 2b/metabolismo , Mutação de Sentido Incorreto , Linhagem , Estrutura Terciária de Proteína , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/química , Proteínas Proto-Oncogênicas c-ret , Receptores Proteína Tirosina Quinases/química , Transformação Genética , Tirosina/genética
20.
Br J Haematol ; 105(1): 50-7, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10233362

RESUMO

Glial cell line-derived neurotrophic factor (GDNF) and neurturin (NTN) mediate their actions through a unique multicomponent receptor system composed of Ret receptor tyrosine kinase and glycosyl-phosphatidylinositol-linked cell surface proteins (designated GFRalpha-1 and GFRalpha-2). In the present study, expression of these signalling components in the process of differentiation of haemopoietic cells was investigated. Ret was expressed at variable levels in normal and malignant cells of the myelomonocyte lineage. Immunohistochemical analysis of human and mouse tissues revealed that Ret expression was increased in intermediate mature myeloid cells such as promyelocytes and myelocytes and decreased in mature granulocytes and monocytes. Consistent with this observation, when THP-1 monocytic and HL-60 promyelocytic leukaemia cells expressing Ret were differentiated toward macrophages or granulocytes by treatment of 12-O-tetradecanoylphorbol-13-acetate (TPA) or all-trans retinoic acid (RA), Ret expression strikingly decreased during differentiation. Expression of GDNF, NTN, GFRalpha-1 and GFRalpha-2 was undetectable in THP-1 and HL-60 cells as well as in bone marrow haemopoietic cells. In contrast, bone marrow stromal cells appeared to express GDNF, GFRalpha-1 and GFRalpha-2 but not Ret. These findings suggested that the interaction between stromal cells and Ret-expressing haemopoietic cells in the bone marrow microenvironment may play a role in the differentiation of myelomonocyte-lineage cells through activation of the GDNF/Ret signalling pathway.


Assuntos
Células da Medula Óssea/citologia , Células-Tronco Hematopoéticas/citologia , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais , Animais , Diferenciação Celular , Regulação para Baixo , Humanos , Imuno-Histoquímica , Leucemia/metabolismo , Leucemia/patologia , Camundongos , RNA Neoplásico/metabolismo , Células Tumorais Cultivadas
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