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1.
NMR Biomed ; 29(11): 1577-1589, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27717037

RESUMO

Glioma models have provided important insights into human brain cancers. Among the investigative tools, MRI has allowed their characterization and diagnosis. In this study, we investigated whether diffusion MRI might be a useful technique for early detection and characterization of slow-growing and diffuse infiltrative gliomas, such as the proposed new models, LN-2669GS and LN-2540GS glioma sphere xenografts. Tumours grown in these models are not visible in conventional T2 -weighted or contrast-enhanced T1 -weighted MRI at 14.1 T. Diffusion-weighted imaging and diffusion tensor imaging protocols were optimized for contrast by exploring long diffusion times sensitive for probing the microstructural alterations induced in the normal brain by the slow infiltration of glioma sphere cells. Compared with T2 -weighted images, tumours were properly identified in their early stage of growth using diffusion MRI, and confirmed by localized proton MR spectroscopy as well as immunohistochemistry. The first evidence of tumour presence was revealed for both glioma sphere xenograft models three months after tumour implantation, while no necrosis, oedema or haemorrhage were detected either by MRI or by histology. Moreover, different values of diffusion indices, such as mean diffusivity and fractional anisotropy, were obtained in tumours grown from LN-2669GS and LN-2540GS glioma sphere lines. These observations highlighted diverse tumour microstructures for both xenograft models, which were reflected in histology. This study demonstrates the ability of diffusion MRI techniques to identify and investigate early stages of slow-growing, invasive tumours in the mouse brain, thus providing a potential imaging biomarker for early detection of tumours in humans.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Detecção Precoce de Câncer/métodos , Glioma/diagnóstico por imagem , Glioma/patologia , Algoritmos , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Camundongos , Camundongos Nus , Invasividade Neoplásica , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Esferoides Celulares/patologia
2.
Appl Radiat Isot ; 67(7-8 Suppl): S365-8, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19375924

RESUMO

The aim of this study was to evaluate in vivo the boron biodistribution and pharmacokinetics of 4-borono-2-fluorophenylalanine ((19)F-BPA) using (19)F MR Imaging ((19)F MRI) and Spectroscopy ((19)F MRS). The correlation between the results obtained by both techniques, (19)F MRI on rat brain and (19)F MRS on blood samples, showed the maximum (19)F-BPA uptake in C6 glioma model at 2.5h after infusion determining the optimal irradiation time. Moreover, the effect of L-DOPA as potential enhancer of (19)F-BPA tumour intake was assessed using (19)F MRI.


Assuntos
Compostos de Boro/farmacocinética , Terapia por Captura de Nêutron de Boro/métodos , Flúor/análise , Flúor/farmacocinética , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Fenilalanina/análogos & derivados , Animais , Compostos de Boro/uso terapêutico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/radioterapia , Linhagem Celular Tumoral , Glioma/metabolismo , Glioma/radioterapia , Técnicas In Vitro , Masculino , Fenilalanina/farmacocinética , Fenilalanina/uso terapêutico , Radiossensibilizantes/farmacocinética , Radiossensibilizantes/uso terapêutico , Ratos , Ratos Wistar , Distribuição Tecidual
3.
Appl Radiat Isot ; 67(7-8 Suppl): S34-6, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19375337

RESUMO

One of the main limitations for BNCT effectiveness is the insufficient intake of (10)B nuclei within tumour cells. This work was aimed at investigating the use of L-DOPA as enhancer for boronophenylalanine (BPA) uptake in the C6 glioma model. The investigation was first performed in vitro, and then extended in vivo to the animal model. BPA accumulation in C6 glioma cells was assessed, using radiowave dielectric spectroscopy (RDS), with and without L-DOPA preloading. C6 glioma cells were also implanted in the brain of 25 rats, randomly assigned to two experimental branches: (1) intra-carotid BPA infusion; (2) intra-carotid BPA infusion after pre-treatment with L-DOPA, administrated 24 h before BPA infusion. All animals were sacrificed, and assessment of BPA concentrations in tumour tissue, normal brain, and blood samples was performed using high performance liquid chromatography (HPLC). L-DOPA preloading induced a massive increase of BPA concentration either in vitro on C6 glioma cells or in vivo in the animal model tumour. Moreover, no significant difference was found in the normal brain and blood samples between the two animal groups. This study suggests the potential use of L-DOPA as enhancer for BPA accumulation in malignant gliomas eligible for BNCT.


Assuntos
Compostos de Boro/administração & dosagem , Compostos de Boro/farmacocinética , Neoplasias Encefálicas/metabolismo , Glioma/metabolismo , Levodopa/administração & dosagem , Fenilalanina/análogos & derivados , Radiossensibilizantes/administração & dosagem , Radiossensibilizantes/farmacocinética , Animais , Compostos de Boro/uso terapêutico , Terapia por Captura de Nêutron de Boro , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Linhagem Celular Tumoral , Glioma/patologia , Glioma/radioterapia , Técnicas In Vitro , Imageamento por Ressonância Magnética , Masculino , Fenilalanina/administração & dosagem , Fenilalanina/farmacocinética , Fenilalanina/uso terapêutico , Radiossensibilizantes/uso terapêutico , Ratos , Ratos Wistar
4.
Abdom Imaging ; 25(1): 45-7, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10652920

RESUMO

Differentiating bowel intussusception occurring in adults from other bowel diseases represents a diagnostic problem because this condition is not a common finding. Contrast radiography, computed tomography, magnetic resonance imaging, and abdominal ultrasonography are imaging techniques suitable for this diagnosis. Sonography is easy to perform, reproducible, and less invasive than the other techniques. The aim of the present study was to evaluate the diagnostic utility of abdominal sonography in four patients affected by bowel intussusception and to assess the advantages offered by this method.


Assuntos
Valva Ileocecal/diagnóstico por imagem , Intussuscepção/diagnóstico por imagem , Doenças do Jejuno/diagnóstico por imagem , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Doenças do Íleo/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Ultrassonografia
5.
J Hepatol ; 25(2): 212-7, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8878784

RESUMO

BACKGROUND: The clinical outcome of hepatitis virus infections is though to depend on the complex interplay between the host immune response profile and virus factors. 90K/MAC-2 BP is a novel member of the Scavenger Receptor Cysteine Rich protein superfamily that functions as a molecular alarm signal for the cellular immune system against both cancer cells and virus infections. METHODS: To assess the significance and the potential clinical usefulness of testing for serum levels of 90K/MAC-2 BP in chronic viral hepatitis patients we studied 115 consecutive patients with chronic HCV hepatitis, 28 HBsAg chronic hepatitis patients, 12 asymptomatic HCV carriers and 11 asymptomatic HBV carriers. 103 out of the 115 HCV patients have been treated with recombinant alpha 2a-interferon at the dose of 3 Mega Units (MU) t.i.w. for 6 months followed by 1.5 MU t.i.w. for 6 months, and have been followed up for a further 12 months. Serum levels of 90K/MAC-2 BP were measured by an immunoradiometric assay based on the specific SP-2 monoclonal antibody. RESULTS AND CONCLUSIONS: Serum 90K/MAC-2 BP levels are increased in chronic viral hepatitis patients, being significantly higher in HCV than in HBV patients. In chronic HCV hepatitis, serum 90K/MAC-2 BP levels are related to both the degree of disease severity and duration of infection. Moreover, elevated 90K/MAC-2 BP serum levels are an independent predictor of failure to respond to alpha-interferon treatment in a cohort of community-acquired chronic hepatitis C patients.


Assuntos
Proteínas de Transporte/sangue , Glicoproteínas/sangue , Hepatite C/terapia , Interferon-alfa/uso terapêutico , Lipoproteínas/sangue , Proteínas de Neoplasias/sangue , Adulto , Idoso , Antígenos de Neoplasias , Biomarcadores Tumorais , Portador Sadio/sangue , Doença Crônica , Estudos de Coortes , Feminino , Previsões , Hepatite B/sangue , Hepatite B/fisiopatologia , Hepatite B/terapia , Hepatite C/sangue , Hepatite C/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Falha de Tratamento
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