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1.
Immunity ; 56(6): 1187-1203.e12, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37160118

RESUMO

B7 ligands (CD80 and CD86), expressed by professional antigen-presenting cells (APCs), activate the main co-stimulatory receptor CD28 on T cells in trans. However, in peripheral tissues, APCs expressing B7 ligands are relatively scarce. This raises the questions of whether and how CD28 co-stimulation occurs in peripheral tissues. Here, we report that CD8+ T cells displayed B7 ligands that interacted with CD28 in cis at membrane invaginations of the immunological synapse as a result of membrane remodeling driven by phosphoinositide-3-kinase (PI3K) and sorting-nexin-9 (SNX9). cis-B7:CD28 interactions triggered CD28 signaling through protein kinase C theta (PKCθ) and promoted CD8+ T cell survival, migration, and cytokine production. In mouse tumor models, loss of T cell-intrinsic cis-B7:CD28 interactions decreased intratumoral T cells and accelerated tumor growth. Thus, B7 ligands on CD8+ T cells can evoke cell-autonomous CD28 co-stimulation in cis in peripheral tissues, suggesting cis-signaling as a general mechanism for boosting T cell functionality.


Assuntos
Antígenos CD28 , Linfócitos T CD8-Positivos , Camundongos , Animais , Antígenos CD28/metabolismo , Antígenos CD/metabolismo , Ligantes , Membranas Sinápticas/metabolismo , Antígeno B7-2 , Glicoproteínas de Membrana/metabolismo , Antígeno B7-1/metabolismo , Moléculas de Adesão Celular , Ativação Linfocitária
2.
J Immunother Cancer ; 11(5)2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37188395

RESUMO

BACKGROUND: Discovery that ~16% of T cells naturally co-express two T-cell receptor (TCR) clonotypes prompts examining the role of dual TCR cells in immune functions. METHODS: Using TCRα-reporter transgenic mice, enabling unambiguous identification of single-TCR and dual-TCR cells, we tested the role of dual TCR cells in antitumor immune responses against immune-responsive syngeneic 6727 sarcoma and immune-resistant B16F10 melanoma. RESULTS: Dual TCR cells were specifically increased among tumor-infiltrating lymphocytes (TILs) in both models, indicating selective advantage in antitumor responses. Phenotype and single-cell gene expression analyses identified dual TCR are predominant during the effective antitumor response, demonstrating selectively increased activation in the TIL compartment and skewing toward an effector memory phenotype. Absence of dual TCR cells impaired immune response to B16F10 but not 6727, suggesting that dual TCR cells may be more influential in responses against poorly immunogenic tumors. Dual TCR cells demonstrated an advantage in recognition of B16F10-derived neoantigens in vitro, providing a mechanistic basis for their antitumor reactivity. CONCLUSIONS: These results discover an unrecognized role for dual TCR cells in protective immune function and identify these cells and their TCRs as a potential resource for antitumor immunotherapy.


Assuntos
Melanoma , Linfócitos T , Camundongos , Animais , Antígenos de Neoplasias , Receptores de Antígenos de Linfócitos T , Imunidade
3.
Plants (Basel) ; 11(9)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35567144

RESUMO

Upon mechanical damage, plants produce wound responses to protect internal tissues from infections and desiccation. Suberin, a heteropolymer found on the inner face of primary cell walls, is deposited in specific tissues under normal development, enhanced under abiotic stress conditions and synthesized by any tissue upon mechanical damage. Wound-healing suberization of tree bark has been investigated at the anatomical level but very little is known about the molecular mechanisms underlying this important stress response. Here, we investigated a time course of wound-induced suberization in poplar bark. Microscopic changes showed that polyphenolics accumulate 3 days post wounding, with aliphatic suberin deposition observed 5 days post wounding. A wound periderm was formed 9 days post wounding. Chemical analyses of the suberin polyester accumulated during the wound-healing response indicated that suberin monomers increased from 0.25 to 7.98 mg/g DW for days 0 to 28, respectively. Monomer proportions varied across the wound-healing process, with an overall ratio of 2:1 (monomers:glycerol) found across the first 14 days post wounding, with this ratio increasing to 7:2 by day 28. The expression of selected candidate genes of poplar suberin metabolism was investigated using qRT-PCR. Genes queried belonging to lipid polyester and phenylpropanoid metabolism appeared to have redundant functions in native and wound-induced suberization. Our data show that, anatomically, the wounding response in poplar bark is similar to that described in periderms of other species. It also provides novel insight into this process at the chemical and molecular levels, which have not been previously studied in trees.

4.
Nat Cell Biol ; 24(6): 954-967, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35637408

RESUMO

Epidemiological studies demonstrate an association between breast cancer (BC) and systemic dysregulation of glucose metabolism. However, how BC influences glucose homeostasis remains unknown. We show that BC-derived extracellular vesicles (EVs) suppress pancreatic insulin secretion to impair glucose homeostasis. EV-encapsulated miR-122 targets PKM in ß-cells to suppress glycolysis and ATP-dependent insulin exocytosis. Mice receiving high-miR-122 EVs or bearing BC tumours exhibit suppressed insulin secretion, enhanced endogenous glucose production, impaired glucose tolerance and fasting hyperglycaemia. These effects contribute to tumour growth and are abolished by inhibiting EV secretion or miR-122, restoring PKM in ß-cells or supplementing insulin. Compared with non-cancer controls, patients with BC have higher levels of circulating EV-encapsulated miR-122 and fasting glucose concentrations but lower fasting insulin; miR-122 levels are positively associated with glucose and negatively associated with insulin. Therefore, EV-mediated impairment of whole-body glycaemic control may contribute to tumour progression and incidence of type 2 diabetes in some patients with BC.


Assuntos
Neoplasias da Mama , Diabetes Mellitus Tipo 2 , Vesículas Extracelulares , MicroRNAs , Animais , Neoplasias da Mama/patologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Vesículas Extracelulares/metabolismo , Feminino , Glucose/metabolismo , Homeostase , Humanos , Insulina/metabolismo , Secreção de Insulina , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo
5.
Cancers (Basel) ; 13(6)2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33805661

RESUMO

The limitations of the biomarker prostate-specific antigen (PSA) necessitate the pursuit of biomarkers capable of better identifying high-risk prostate cancer (PC) patients in order to improve their therapeutic management and outcomes. Aggressive prostate tumors characteristically exhibit high rates of glycolysis and lipogenesis. Glycerol 3-phosphate phosphatase (G3PP), also known as phosphoglycolate phosphatase (PGP), is a recently identified mammalian enzyme, shown to play a role in the regulation of glucose metabolism, lipogenesis, lipolysis, and cellular nutrient-excess detoxification. We hypothesized that G3PP may relieve metabolic stress in cancer cells and assessed the association of its expression with PC patient prognosis. Using immunohistochemical staining, we assessed the epithelial expression of G3PP in two different radical prostatectomy (RP) cohorts with a total of 1797 patients, for whom information on biochemical recurrence (BCR), metastasis, and mortality was available. The association between biomarker expression, biochemical recurrence (BCR), bone metastasis, and prostate cancer-specific survival was established using log-rank and multivariable Cox regression analyses. High expression of G3PP in PC epithelial cells is associated with an increased risk of BCR, bone metastasis, and PC-specific mortality. Multivariate analysis revealed high G3PP expression in tumors as an independent predictor of BCR and bone metastasis development. High G3PP expression in tumors from patients eligible for prostatectomies is a new and independent prognostic biomarker of poor prognosis and aggressive PC for recurrence, bone metastasis, and mortality.

6.
PLoS Med ; 16(7): e1002847, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31265453

RESUMO

BACKGROUND: The identification of patients with high-risk prostate cancer (PC) is a major challenge for clinicians, and the improvement of current prognostic parameters is an unmet clinical need. We and others have identified an association between the nuclear localization of NF-κB p65 and biochemical recurrence (BCR) in PC in small and/or single-centre cohorts of patients. METHODS AND FINDINGS: In this study, we accessed 2 different multi-centre tissue microarrays (TMAs) representing cohorts of patients (Test-TMA and Validation-TMA series) of the Canadian Prostate Cancer Biomarker Network (CPCBN) to validate the association between p65 nuclear frequency and PC outcomes. Immunohistochemical staining of p65 was performed on the Test-TMA and Validation-TMA series, which include PC tissues from patients treated by first-line radical prostatectomy (n = 250 and n = 1,262, respectively). Two independent observers evaluated the p65 nuclear frequency in digital images of cancer tissue and benign adjacent gland tissue. Kaplan-Meier curves coupled with a log-rank test and univariate and multivariate Cox regression models were used for statistical analyses of continuous values and dichotomized data (cutoff of 3%). Multivariate analysis of the Validation-TMA cohort showed that p65 nuclear frequency in cancer cells was an independent predictor of BCR using continuous (hazard ratio [HR] 1.02 [95% CI 1.00-1.03], p = 0.004) and dichotomized data (HR 1.33 [95% CI 1.09-1.62], p = 0.005). Using a cutoff of 3%, we found that this biomarker was also associated with the development of bone metastases (HR 1.82 [95% CI 1.05-3.16], p = 0.033) and PC-specific mortality (HR 2.63 [95% CI 1.30-5.31], p = 0.004), independent of clinical parameters. BCR-free survival, bone-metastasis-free survival, and PC-specific survival were shorter for patients with higher p65 nuclear frequency (p < 0.005). As the small cores on TMAs are a limitation of the study, a backward validation of whole PC tissue section will be necessary for the implementation of p65 nuclear frequency as a PC biomarker in the clinical workflow. CONCLUSIONS: We report the first study using the pan-Canadian multi-centre cohorts of CPCBN and validate the association between increased frequency of nuclear p65 frequency and a risk of disease progression.


Assuntos
Biomarcadores Tumorais/análise , Núcleo Celular/química , Imuno-Histoquímica , Neoplasias da Próstata/química , Fator de Transcrição RelA/análise , Idoso , Neoplasias Ósseas/secundário , Canadá , Núcleo Celular/patologia , Progressão da Doença , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Variações Dependentes do Observador , Valor Preditivo dos Testes , Intervalo Livre de Progressão , Prostatectomia , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Análise Serial de Tecidos
7.
Am J Pathol ; 189(7): 1451-1461, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31202437

RESUMO

Prostate cancer (PC) commonly metastasizes to the bone, resulting in pathologic fractures and poor prognosis. CCN3/nephroblastoma overexpressed is a secreted protein with a known role in promoting breast cancer metastasis to bone. However, in PC, CCN3 has been ascribed conflicting roles; some studies suggest that CCN3 promotes PC metastasis, whereas others argue a tumor suppressor role for CCN3 in this disease. Indeed, in the latter context, CCN3 has been shown to sequester the androgen receptor (AR) and suppress AR signaling. In the present study, we demonstrate that CCN3 functions as a bone-metastatic mediator, which is dependent on its C-terminal domain for this function. Analysis of tissue microarrays comprising >1500 primary PC patient radical prostatectomy specimens reveals that CCN3 expression correlates with aggressive disease and is negatively correlated with the expression of prostate-specific antigen, a marker of AR signaling. Together, these findings point to CCN3 as a biomarker to predict PC aggressiveness while providing clarity on its role as a functional mediator of PC bone metastasis.


Assuntos
Neoplasias Ósseas/metabolismo , Proteína Sobre-Expressa em Nefroblastoma/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Ósseas/secundário , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Calicreínas/biossíntese , Calicreínas/genética , Masculino , Metástase Neoplásica , Proteínas de Neoplasias , Antígeno Prostático Específico/biossíntese , Antígeno Prostático Específico/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Transdução de Sinais/genética
8.
J Immunother Cancer ; 7(1): 86, 2019 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-30922393

RESUMO

BACKGROUND: Permanence of front-line management of lung cancer by immunotherapies requires predictive companion diagnostics identifying immune-checkpoints at baseline, challenged by the size and heterogeneity of biopsy specimens. METHODS: An innovative, tumor heterogeneity reducing, immune-enriched tissue microarray was constructed from baseline biopsies, and multiplex immunofluorescence was used to profile 25 immune-checkpoints and immune-antigens. RESULTS: Multiple immune-checkpoints were ranked, correlated with antigen presenting and cytotoxic effector lymphocyte activity, and were reduced with advancing disease. Immune-checkpoint combinations on TILs were associated with a marked survival advantage. Conserved combinations validated on more than 11,000 lung, breast, gastric and ovarian cancer patients demonstrate the feasibility of pan-cancer companion diagnostics. CONCLUSIONS: In this hypothesis-generating study, deepening our understanding of immune-checkpoint biology, comprehensive protein-protein interaction and pathway mapping revealed that redundant immune-checkpoint interactors associate with positive outcomes, providing new avenues for the deciphering of molecular mechanisms behind effects of immunotherapeutic agents targeting immune-checkpoints analyzed.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias/imunologia , Neoplasias/patologia , Análise Serial de Tecidos/métodos , Estudos de Viabilidade , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imunoterapia , Masculino , Neoplasias/tratamento farmacológico , Prognóstico , Mapas de Interação de Proteínas , Análise de Sobrevida
9.
Sci Rep ; 6: 27485, 2016 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-27270835

RESUMO

Mutations in the CdGAP/ARHGAP31 gene, which encodes a GTPase-activating protein for Rac1 and Cdc42, have been reported causative in the Adams-Oliver developmental syndrome often associated with vascular defects. However, despite its abundant expression in endothelial cells, CdGAP function in the vasculature remains unknown. Here, we show that vascular development is impaired in CdGAP-deficient mouse embryos at E15.5. This is associated with superficial vessel defects and subcutaneous edema, resulting in 44% embryonic/perinatal lethality. VEGF-driven angiogenesis is defective in CdGAP(-/-) mice, showing reduced capillary sprouting from aortic ring explants. Similarly, VEGF-dependent endothelial cell migration and capillary formation are inhibited upon CdGAP knockdown. Mechanistically, CdGAP associates with VEGF receptor-2 and controls VEGF-dependent signaling. Consequently, CdGAP depletion results in impaired VEGF-mediated Rac1 activation and reduced phosphorylation of critical intracellular mediators including Gab1, Akt, PLCγ and SHP2. These findings are the first to demonstrate the importance of CdGAP in embryonic vascular development and VEGF-induced signaling, and highlight CdGAP as a potential therapeutic target to treat pathological angiogenesis and vascular dysfunction.


Assuntos
Vasos Sanguíneos/embriologia , Proteínas Ativadoras de GTPase/fisiologia , Neovascularização Fisiológica/fisiologia , Fator A de Crescimento do Endotélio Vascular/fisiologia , Proteína cdc42 de Ligação ao GTP/fisiologia , Animais , Camundongos , Camundongos Knockout
10.
Cell Signal ; 26(6): 1283-93, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24583284

RESUMO

The protein tyrosine phosphatase DEP-1/PTPRJ positively regulates Src family kinases and critical biological functions in endothelial and hematopoietic cells. Phosphorylation of DEP-1 on Y1311/Y1320 mediates the association and activation of Src, and promotes Src-dependent angiogenic responses including endothelial cell permeability. We have identified T1318 as a phosphorylated residue proximal to Y1320. The aim of this study was to determine if T1318 phosphorylation exerts a regulatory role over the function of DEP-1. We show that phosphorylation of DEP-1 on Y1320 was reduced when T1318 was mutated. This led to the decreased association of DEP-1 T1318A with Src, and defective Src activation in both HEK 293T and VEGF-stimulated endothelial cells. Consistent with these findings, VEGF-induced tyrosine phosphorylation of VE-cadherin, its association to ß-arrestin1/2, and cell permeability were impaired in cells expressing DEP-1 T1318A. Conversely, expression of the phosphomimetic mutant DEP-1 T1318E constitutively enhanced the phosphorylation of Y1320 and VE-cadherin over that induced by WT DEP-1, and resulted in increased VEGF-dependent permeability. DEP-1 T1318 is part of a CK2 consensus phosphorylation site and was identified as a CK2 substrate. Modulation of CK2 expression or activity in endothelial cells regulated T1318 phosphorylation, and correlated with the status of Y1320 phosphorylation, Src activation, and cell permeability. CK2-dependent phosphorylation of DEP-1 T1318 promotes Y1320 phosphorylation and Src activation upon VEGF stimulation. Phosphorylation of T1318 is thus part of a regulatory mechanism that channels the activity of DEP-1 towards Src to allow its optimal activation and the promotion of endothelial cell permeability.


Assuntos
Células Endoteliais da Veia Umbilical Humana/metabolismo , Processamento de Proteína Pós-Traducional , Fator A de Crescimento do Endotélio Vascular/fisiologia , Sequência de Aminoácidos , Animais , Caseína Quinase II/metabolismo , Bovinos , Permeabilidade da Membrana Celular , Ativação Enzimática , Células HEK293 , Humanos , Fosforilação , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores/metabolismo , Treonina/metabolismo , Quinases da Família src/metabolismo
11.
Blood ; 120(13): 2745-56, 2012 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-22898603

RESUMO

DEP-1/CD148 is a receptor-like protein tyrosine phosphatase with antiproliferative and tumor-suppressive functions. Interestingly, it also positively regulates Src family kinases in hematopoietic and endothelial cells, where we showed it promotes VE-cadherin-associated Src activation and endothelial cell survival upon VEGF stimulation. However, the molecular mechanism involved and its biologic functions in endothelial cells remain ill-defined. We demonstrate here that DEP-1 is phosphorylated in a Src- and Fyn-dependent manner on Y1311 and Y1320, which bind the Src SH2 domain. This allows DEP-1-catalyzed dephosphorylation of Src inhibitory Y529 and favors the VEGF-induced phosphorylation of Src substrates VE-cadherin and Cortactin. Accordingly, RNA interference (RNAi)-mediated knockdown of DEP-1 or expression of DEP-1 Y1311F/Y1320F impairs Src-dependent biologic responses mediated by VEGF including permeability, invasion, and branching capillary formation. In addition, our work further reveals that above a threshold expression level, DEP-1 can also dephosphorylate Src Y418 and attenuate downstream signaling and biologic responses, consistent with the quiescent behavior of confluent endothelial cells that express the highest levels of endogenous DEP-1. Collectively, our findings identify the VEGF-dependent phosphorylation of DEP-1 as a novel mechanism controlling Src activation, and show this is essential for the proper regulation of permeability and the promotion of the angiogenic response.


Assuntos
Capilares/metabolismo , Permeabilidade da Membrana Celular , Endotélio Vascular/citologia , Neovascularização Patológica , Tirosina/metabolismo , Quinases da Família src/metabolismo , Antígenos CD/metabolismo , Western Blotting , Caderinas/metabolismo , Adesão Celular , Movimento Celular , Proliferação de Células , Células Cultivadas , Cortactina/metabolismo , Endotélio Vascular/metabolismo , Imunofluorescência , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Imunoprecipitação , Mutação/genética , Invasividade Neoplásica , Fosforilação , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores/genética , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores/metabolismo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo
12.
Cell Signal ; 21(6): 943-53, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19233262

RESUMO

Gab1 was previously described as a positive modulator of Akt, Src, ERK1/2, endothelial cell migration, and capillary formation in response to vascular endothelial growth factor (VEGF). However, its involvement in endothelial cell survival, as well as the potential contribution of the other family member Gab2 to signalling and biological responses remained unknown. Here, we show that Gab2 is tyrosine phosphorylated in a Grb2-dependent manner downstream of activated VEGF receptor-2 (VEGFR2), and that it associates with signalling proteins including PI3K and SHP2, but apparently not with the receptor. Similarly to Gab1, over-expression of Gab2 induces endothelial cell migration in response to VEGF, whereas its depletion using siRNAs results in its reduction. Importantly, depletion of both Gab1 and Gab2 leads to an even greater inhibition of VEGF-induced cell migration. However, contrary to what has been reported for Gab1, the silencing of Gab2 results in increased Src, Akt and ERK1/2 activation, slightly reduced p38 phosphorylation, and up-regulation of Gab1 protein levels. Accordingly, re-expression of Gab2 in Gab2-/- fibroblasts leads to opposite results, suggesting that the modulation of both Gab2 and Gab1 expression in these conditions might contribute to the impaired signalling observed. Consistent with their opposite roles on Akt, the depletion of Gab1, but not of Gab2, results in reduced FOXO1 phosphorylation and VEGF-mediated endothelial cell survival. Mutation of VEGFR2 Y801 and Y1214, which abrogates the phosphorylation of Gab1, also correlates with inhibition of Akt. Altogether, these results underscore the non-redundant and essential roles of Gab1 and Gab2 in endothelial cells, and suggest major contributions of these proteins during in vivo angiogenesis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Movimento Celular/efeitos dos fármacos , Células Endoteliais/citologia , Fosfoproteínas/metabolismo , Fator A de Crescimento do Endotélio Vascular/farmacologia , Animais , Bovinos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Ativação Enzimática/efeitos dos fármacos , Humanos , Camundongos , Proteínas Mutantes/metabolismo , Fosfoproteínas/deficiência , Fosforilação/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
13.
Dig Dis Sci ; 52(10): 2601-9, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17429735

RESUMO

The noninvasive evaluation of liver fibrosis is a major clinical goal in liver diseases. Our aim was to identify MRI parameters to quantify liver fibrosis in vivo in an animal model of liver fibrosis with slight inflammation. We evaluated serum hyaluronate, liver hydroxyproline, area of liver fibrosis (image analysis), and 1.5-T MRI in 10 sham rats and 24 bile duct ligated rats with different stages of liver fibrosis. Liver signal intensity (SI)/muscle SI ratio and liver relaxation times (rT) were measured on T1 and T2 weighted sequences at different echo (TE) or recovery (RT) times of MRI. Among the 66 MRI parameters tested, the highest correlation with the area of fibrosis was observed for rT2 (r=0.78, P < 0.01). The area of liver fibrosis was independently predicted by five MRI variables (adjusted R (2)=0.78, with R (2)=0.64 for rT2 and rT1). Diagnostic accuracy for liver fibrosis was 100% using two variables: liver/muscle SI ratio on T2 at 30-ms TE and liver/muscle SI ratio on T1 at 50-ms RT. We conclude that in this animal model, fibrosis could be diagnosed with an accuracy of 100% using two MRI parameters. The quantification of liver fibrosis was very accurate either with only one MRI parameter (r=0.78 for rT2) or with five parameters (r=0.90) in this cholestatic model.


Assuntos
Ductos Biliares Extra-Hepáticos/cirurgia , Cirrose Hepática Experimental/patologia , Imageamento por Ressonância Magnética/métodos , Animais , Ligadura/efeitos adversos , Cirrose Hepática Experimental/etiologia , Valor Preditivo dos Testes , Ratos , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
14.
Eur Radiol ; 16(7): 1501-8, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16485132

RESUMO

The distinction between intracellular (ICE) and extracellular edema (ECE) has a crucial prognostic and therapeutic importance in patients with severe traumatic brain injury (STBI). Indeed, ICE usually leads to cellular death, and maintenance of a cerebral perfusion pressure (CPP) above 70 mmHg is still under debate since this practice may increase ECE. The purpose of this study was to describe the ECE and ICE kinetics associated with STBI using quantitative diffusion MRI. Twelve patients were prospectively studied. The initial ADC in ICE measured on day 1.3+/-0.7 is significantly reduced compared to normal-appearing parenchyma (0.51+/-0.12 * 10(-3) mm2/s vs. 0.76+/-0.03 * 10(-3) mm2/s, n=12, P<0.0001) and reaches normality on MRI 3 performed on day 14.2+/-3.3. In patients presenting an extension of ICE on MRI 2 performed on day 6.7+/-1.4 (ADC(MRI2)=0.40+/-0.11 * 10(-3) mm2/s), ADC values in the extension area at the first MRI were slightly, but not significantly reduced compared to normal parenchyma (0.69+/-0.05 * 10(-3) mm2/s, P=0.29). Normalization occurred equally by day 14. ADC in ECE (1.34+/-0.22 * 10(-3) mm2/s) was elevated and stable with time under CPP therapy. Therefore, ECE is not worsened by CCP therapy, and ICE appears more relevant than ECE in STBI.


Assuntos
Água Corporal/metabolismo , Edema Encefálico/diagnóstico , Edema Encefálico/metabolismo , Lesões Encefálicas/diagnóstico , Lesões Encefálicas/metabolismo , Encéfalo/metabolismo , Imagem de Difusão por Ressonância Magnética/métodos , Adolescente , Adulto , Encéfalo/patologia , Edema Encefálico/etiologia , Lesões Encefálicas/complicações , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Cinética , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Estudos Prospectivos
15.
J Pediatr Orthop ; 26(1): 119-24, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16439915

RESUMO

The purpose of this study was to determine whether there is a significant association between function and well-being in children with cerebral palsy. To determine this, the authors used validated measures of function (Gillette Functional Assessment Questionnaire, Gross Motor Function Classification System, Gross Motor Function Measure, and walking speed) and correlated them to health-related quality of life (HRQOL) measures (Pediatric Outcomes Data Collection Instrument, Pediatric Quality of Life instrument). In a cross-sectional study of ambulatory children with mild to moderate cerebral palsy aged 10.2 +/- 3.2 years, mild to moderate decreases in function were found when compared with normative data. As the assessment of HRQOL comprises both functional well-being and psychosocial well-being, the authors decided to specify the aspect of well-being to which they were referring. It was found that the child's function was not correlated to psychosocial well-being. The children with mild cerebral palsy had greater effects on their psychosocial well-being than would be predicted by their functional disability. Functional measures were good at predicting the functional well-being but were weak at predicting the psychosocial arm of well-being.


Assuntos
Atividades Cotidianas , Paralisia Cerebral/diagnóstico , Paralisia Cerebral/psicologia , Proteção da Criança , Qualidade de Vida , Adaptação Fisiológica , Adaptação Psicológica , Adolescente , California , Paralisia Cerebral/terapia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Masculino , Índice de Gravidade de Doença , Perfil de Impacto da Doença , Caminhada/fisiologia
16.
AJR Am J Roentgenol ; 184(1): 55-62, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15615951

RESUMO

OBJECTIVE: Our purpose was to compare the accuracy of MR cholangiopancreatography and endoscopic sonography for the diagnosis of common bile duct stones in patients with a mild to moderate clinical suspicion of common bile duct stones. SUBJECTS AND METHODS: Forty-seven patients were prospectively enrolled. Inclusion criteria included acute pancreatitis, subclinical jaundice, and clinical features of common bile duct stone migration. Radial endoscopic sonography and MR cholangiopancreatography with the single-shot fast spin-echo technique were performed a maximum of 48 hr apart. The gold-standard diagnosis was obtained with ERCP (n = 20) or intraoperative cholangiography (n = 14) if the results of endoscopic sonography or MR cholangiopancreatography were abnormal or if a cholecystectomy was performed, or by clinical and biochemical follow-up (n = 11) if the results of endoscopic sonography and MR cholangiopancreatography were normal. RESULTS: The final diagnosis was common bile duct stones in 16 patients, malignant obstructions in four, and another biliary disease in two (lithiasis migration aspect with papillary edema); 23 patients had no biliary disease. The sensitivity and specificity of MR cholangiopancreatography were, respectively, 90.5% and 87.5% for etiologic diagnosis and 87.5% and 96.6% for the detection of common bile duct stones. The corresponding values for endoscopic sonography were 86.4% and 91.3% for etiologic diagnosis and 93.8% and 96.6% for visualization of choledocholithiasis. Accuracy did not significantly differ between the techniques. CONCLUSION: In cases of mild to moderate suspicion of choledocholithiasis, the accuracies of endoscopic sonography and MR cholangiopancreatography are similar. Because MR cholangiopancreatography is noninvasive, it may be preferred for this indication.


Assuntos
Coledocolitíase/diagnóstico , Endossonografia , Imageamento por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Coledocolitíase/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade
17.
Eur J Gastroenterol Hepatol ; 16(8): 743-51, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15256975

RESUMO

OBJECTIVES: To determine whether ultrasound and, particularly, new Doppler signs increased the diagnostic accuracy of the most accurate, currently available markers for the diagnosis of cirrhosis or severe fibrosis. METHODS: Thirty-two clinical (n = 4), biochemical (n = 11) and Doppler ultrasound (n = 17) variables were recorded in 106 patients with compensated chronic liver disease. Diagnostic accuracy was evaluated by discriminant analysis; first, globally, using all variables then by stepwise analysis. RESULTS: (A) Diagnosis of cirrhosis. Using Doppler ultrasound, diagnostic accuracy was 92% (95% confidence interval 81-98) globally, and 89% (76-95) with three variables (spleen length, hepatic vein spectrum and maximum portal vein velocity). Based upon clinical signs, diagnostic accuracy was 86% (77-92) globally, and 85% (76-91) with one variable (firm liver). Based upon biochemical parameters, diagnostic accuracy was 80% (70-88) globally, and 81% (72-88) with two variables (hyaluronate and platelet count). Based upon all parameters, diagnostic accuracy was 91% (79-96.5) globally, and 91% (79-96.5) with four variables (firm liver, hyaluronate, platelet and hepatic vein spectrum). On an intention to diagnose basis, Doppler ultrasound provided a lower independent contribution due to missing data. (B) In the diagnosis of severe fibrosis, diagnostic accuracy was 83% (69-92) globally, and 77% (62-87) with one variable. CONCLUSIONS: Cirrhosis can be correctly diagnosed in approximately 90% of patients with compensated chronic liver disease using a few Doppler ultrasound signs including a new sign, the hepatic vein spectrum. Doppler ultrasound could be used for the first line diagnosis and biochemical markers, such as hyaluronate, in patients with missing Doppler ultrasound data.


Assuntos
Cirrose Hepática/diagnóstico por imagem , Fígado/diagnóstico por imagem , Ultrassonografia Doppler , Adulto , Feminino , Fibrose , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Sensibilidade e Especificidade
18.
J Am Coll Surg ; 194(4): 454-62, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11949751

RESUMO

BACKGROUND: The aim of this study was to evaluate pancreatogastrostomy (PG) permeability after duodenopancreatectomy (PD) and to determine a correlation with pancreatic endocrine and exocrine functions. STUDY DESIGN: This prospective study included 19 patients who underwent PD with PG between 1992 and 1999. There were 12 men and 7 women, with a mean age of 58 years (range 35 to 76 years). The mean interval between operation and evaluation was 40.3 months (range 3 to 104 months). Indications for pancreatectomy were benign lesions (n = 13) or adenocarcinoma (n = 6). Histology of the pancreatic resection margin was normal in all patients with malignancy, and the pancreatic remnant was macroscopically normal without evidence of obstructive pancreatitis. Pancreatic exocrine and endocrine functions were respectively evaluated by fecal-1 elastase and fasting blood glucose concentrations. PG permeability was determined by secretin magnetic resonance cholangiopancreatography (Secretin-MRCP). RESULTS: Anastomotic permeability was considered good in seven patients (group 1, 36.8%), moderately stenosed in six patients (group 2, 31.6%), significantly stenosed in four patients (group 3, 21.1%), and obstructed in two patients (group 4, 10.5%). Fecal-1 elastase concentration was decreased in 18 patients, with a mean concentration of 80 microg/g in group 1, 98 microg/g in group 2, 67 microg/g in group 3, and 0 microg/g in group 4. There was a statistically significant correlation between Secretin-MRCP group and fecal-1 elastase concentration. Results of fasting glucose estimation were normal for 14 of 19 patients. There was no correlation between pancreatic endocrine function and Secretin-MRCP group. CONCLUSIONS: Exocrine pancreatic insufficiency was presented in 95% of the patients despite a PG permeability in 68.4%. These results may be explained in part by neutralization of pancreatic enzymatic secretions by gastric acid.


Assuntos
Imageamento por Ressonância Magnética , Pâncreas/fisiopatologia , Pancreaticoduodenectomia , Secretina , Estômago/cirurgia , Insuficiência Pancreática Exócrina/fisiopatologia , Feminino , Seguimentos , Gastrostomia , Humanos , Ilhotas Pancreáticas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Pancreatopatias/cirurgia , Ductos Pancreáticos/cirurgia , Neoplasias Pancreáticas/cirurgia , Fatores de Tempo
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