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1.
Sci Rep ; 13(1): 22284, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097667

RESUMO

Compared to normal arc-related volcanic eruptions, the formation of a volcanic caldera is a relatively atypical event. During caldera formation a series of large volumes of magma are erupted, reducing the structural support for the rock above the magma chamber and creating a large depression at the surface called caldera. Los Humeros volcanic field (LHVF) represents one of the largest volcanic calderas in Mexico. It is located some 400 km from the trench at the eastern edge of the Trans Mexican Volcanic Belt where the depth to the Cocos slab is more than 300 km. In this study we employ high-resolution two-dimensional thermomechanical numerical simulations of magma intrusions and a horizontal tectonic strain rate to better understand the influence of crustal deformation for the formation of Los Humeros caldera. A minimum number of three thermal anomaly pulses of hydrated mantle material (with diameter of 15 km or more) and a regional strain rate of 7.927 × 10-16 s-1 are required for magma to reach the surface. Modeling results show that regional extension coupled with deep thermal anomalies (with a temperature excess of ΔT ≥ 100 °C) that come in a specific chain-type sequence produce surface deformation patterns similar to LHVF. We propose an asthenospheric sub-slab deep source (> 300 km depth) for the thermal anomalies where previous studies showed the existence of a gap or tear in the Cocos slab.

2.
Sci Rep ; 13(1): 18313, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37880308

RESUMO

The subduction of the Philippine Sea (PHS) plate along the Nankai Trough in in southwest Japan is a relatively recent process compared with subduction along the Japan Trench in northeast Japan. However, the tectonic evolution of the PHS plate along the Nankai Trough is still controversial and not fully understood. There are several competing hypotheses based on different estimates for the time variations of convergence rate and plate age. Our study employs numerical modelling of subduction in order to evaluate the slab evolution for the last 15 Myr and aims to evaluate each tectonic scenario against the present-day slab geometry along a profile passing through the Shikoku and Chugoku regions. The modelling strategy involves a parameter study where subduction initiation and various subduction parameters are analyzed in terms of subduction geometry evolution. Two-dimensional visco-elasto-plastic numerical simulations of spontaneous bending subduction predict that convergence rate and plate age variations play an important role in the evolution of subduction geometry. Modeling results after 15 Myr of evolution reveal that the tectonic model based on a high convergence rate between ~ 15 Ma and ~ 3 Ma produces a slab geometry that agrees well with the observed present-day slab shape specific for the Shikoku and Chugoku regions.

3.
Pharmazie ; 78(5): 56-62, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37189265

RESUMO

Overactive bladder (OAB) is a frequent chronic disorder which impairs quality of life by frequent, uncontrollable urination. Newly developed selectiveß 3-adrenoceptor agonists (sß 3-agonists) have the same efficacy in treating OAB but significantly fewer side effects than the traditionally used anti-muscarinics. However, safety data on these compounds are scarce. In this study, we analysed the occurrence of adverse effects in patients taking sß 3-agonists and their characteristics using the JADER database. The most frequently reported adverse effect associated with the use of sß 3-agonists was urinary retention [mirabegron; crude reporting odds ratios (ROR): 62.1, 95% confidence interval (CI): 52.0-73.6, P<0.001, vibegron; crude ROR: 250, 95% CI : 134-483, P<0.001]. Data from patients with urinary retention were stratified by sex. In both men and women, the rate of urinary retention was higher when using the mirabegron/anti-muscarinic drug when compared to mirabegron monotherapy; its occurrence was higher in men with a history of benign prostatic hypertrophy than in those without. Weibull analysis showed that approximately 50% of sß 3 agonist-induced urinary retention occurred within 15 days after initiation of treatment, and then gradually decreased. Although sß 3-agonists are useful against OAB, they may induce several side effects, especially urinary retention, which can further evolve into more severe conditions. Urinary retention occurs more frequently in patients concomitantly taking medication that either increases urethral resistance or has organic factors that block the urethra. When using sß 3-agonists, the concomitantly used medications and underlying diseases should be thoroughly reviewed, and safety monitoring should be instituted early during the treatment.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Bexiga Urinária Hiperativa , Retenção Urinária , Masculino , Humanos , Feminino , Retenção Urinária/induzido quimicamente , Retenção Urinária/epidemiologia , Retenção Urinária/complicações , Antagonistas Muscarínicos , Qualidade de Vida , População do Leste Asiático , Agonistas de Receptores Adrenérgicos beta 3/efeitos adversos , Bexiga Urinária Hiperativa/tratamento farmacológico , Bexiga Urinária Hiperativa/induzido quimicamente , Bexiga Urinária Hiperativa/complicações , Receptores Adrenérgicos/uso terapêutico , Resultado do Tratamento
5.
J R Soc Interface ; 15(145)2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30089688

RESUMO

This paper reports the structural and optical investigations of the structural colour of the weevil Lamprocyphusaugustus The photonic crystal structure within the weevil's scales was investigated using sequential focused ion-beam milling and scanning electron microscopy imaging. We carefully analysed the reconstructed three-dimensional structure to determine the unit cell of the photonic crystal. It was found that the cuticle network of the cubic unit cell perfectly matches the previously reported diamond-based network. However, different results were obtained for the crystal orientations of the small crystal domains that comprise the entire photonic crystal structure in the scales: <111> directions are highly preferred along the surface normal of the scale. This finding explains the fact that the scale is almost uniformly coloured despite the multi-domain structure. It is confirmed experimentally and theoretically that the wavelength range of the reflection band corresponds to the gap of the photonic band.


Assuntos
Estruturas Animais/ultraestrutura , Pigmentação , Gorgulhos/ultraestrutura , Animais , Microscopia Eletrônica de Varredura
6.
Phys Chem Chem Phys ; 20(7): 4962-4969, 2018 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-29387834

RESUMO

Cationic disorder in the MgAl2O4 spinel induced by swift heavy ions was investigated using the X-ray absorption near edge structure. With changes in the irradiation fluences of 200 MeV Xe ions, the Mg K-edge and Al K-edge spectra were synchronously changed. The calculated spectra based on density function theory indicate that the change in the experimental spectra was due to cationic disorder between Mg in tetrahedral sites and Al in octahedral sites. These results suggest a high inversion degree to an extent that the completely random configuration is achieved in MgAl2O4 induced by the high density electronic excitation under swift heavy ion irradiation.

8.
J Exp Biol ; 219(Pt 24): 3936-3944, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27974535

RESUMO

Morpho butterflies are universally admired for their iridescent blue coloration, which is due to nanostructured wing scales. We performed a comparative study on the coloration of 16 Morpho species, investigating the morphological, spectral and spatial scattering properties of the differently organized wing scales. In numerous previous studies, the bright blue Morpho coloration has been fully attributed to the multi-layered ridges of the cover scales' upper laminae, but we found that the lower laminae of the cover and ground scales play an important additional role, by acting as optical thin film reflectors. We conclude that Morpho coloration is a subtle combination of overlapping pigmented and/or unpigmented scales, multilayer systems, optical thin films and sometimes undulated scale surfaces. Based on the scales' architecture and their organization, five main groups can be distinguished within the genus Morpho, largely agreeing with the accepted phylogeny.


Assuntos
Borboletas/fisiologia , Filogenia , Pigmentação/fisiologia , Animais , Borboletas/anatomia & histologia , Borboletas/ultraestrutura , Fenômenos Ópticos , Espalhamento de Radiação , Especificidade da Espécie , Análise Espectral , Asas de Animais/anatomia & histologia , Asas de Animais/ultraestrutura
9.
Reprod Domest Anim ; 50(2): 283-291, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25626338

RESUMO

Luteinizing hormone LH plays important roles in follicular maturation and ovulation. The effects of LH are mediated by LH receptor (LHR) in the ovary. However, the factors that regulate the expression of LHR in bovine granulosa cells (GCs) are not well known. Insulin-like growth factor-1 (IGF-1) is known to play a key role in the acquisition and maintenance of functional dominance. To better understand the roles of LHR expression and IGF-1, we conducted three experiments to determine (i) mRNA expression of LHR in the GCs of developing follicles, (ii) the effects of IGF-1 on LHR mRNA expression in cultured GCs and (iii) the effects of IGF-1 on estradiol (E2), progesterone (P4) and androstenedione (A4) production by non-luteinized GCs. In experiment 1, small follicles (<6 mm Ø) expressed lower levels of LHR than mid-sized follicles (6-8 mm Ø) and large follicles (≥9 mm Ø) expressed the highest levels of LHR mRNA (p < 0.05). In experiment 2, IGF-1 (1 and 100 ng/ml) increased (p < 0.05) the expression of LHR mRNA in GCs from small and large follicles. In experiment 3, IGF-1 (0.1-100 ng/ml) increased A4 and E2 in GCs from both small and large follicles but increased P4 only in large follicles. IGF-1 in combination with LH (0.1 and 1 ng/ml) increased P4 and A4 in large follicles, and increased E2 and A4 in GCs of small follicles. These findings strongly support the concept that IGF-1 upregulates LHR mRNA expression as well as A4 and E2 production in GCs and that IGF-1 is required for determining which follicle becomes dominant and acquires ovulatory capacity.


Assuntos
Bovinos/fisiologia , Regulação da Expressão Gênica/fisiologia , Células da Granulosa/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Receptores do LH/metabolismo , Androstenodiona/biossíntese , Animais , Estradiol/biossíntese , Feminino , Fator de Crescimento Insulin-Like I/genética , Progesterona/biossíntese , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores do LH/genética
10.
J R Soc Interface ; 11(92): 20131029, 2014 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-24352678

RESUMO

It is known that the wing scales of the emerald-patched cattleheart butterfly, Parides sesostris, contain gyroid-type photonic crystals, which produce a green structural colour. However, the photonic crystal is not a single crystal that spreads over the entire scale, but it is separated into many small domains with different crystal orientations. As a photonic crystal generally has band gaps at different frequencies depending on the direction of light propagation, it seems mysterious that the scale is observed to be uniformly green under an optical microscope despite the multi-domain structure. In this study, we have carefully investigated the structure of the wing scale and discovered that the crystal orientations of different domains are not perfectly random, but there is a preferred crystal orientation that is aligned along the surface normal of the scale. This finding suggests that there is an additional factor during the developmental process of the microstructure that regulates the crystal orientation.


Assuntos
Borboletas/química , Cor , Asas de Animais/química , Asas de Animais/ultraestrutura , Animais , Borboletas/anatomia & histologia , Cristalização , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão
11.
Vet J ; 199(1): 131-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24268486

RESUMO

Although prostaglandin (PG) F2α analogues are routinely used for oestrus synchronisation in cattle, their effects on the function of the bovine corpus luteum (CL), and on ovarian arterial contractility, may not reflect the physiological effects of endogenous PGF2α. In the first of two related experiments, the effects of different analogues of PGF2α (aPGF2α) on the secretory function and apoptosis of cultured bovine cells of the CL were assessed. Enzymatically-isolated bovine luteal cells (from between days 8 and 12 of the oestrous cycle), were stimulated for 24h with naturally-occurring PGF2α or aPGF2α (dinoprost, cloprostenol or luprostiol). Secretion of progesterone (P4) was determined and cellular [Ca(2+)]i mobilisation, as well as cell viability and apoptosis were measured. Naturally-occurring PGF2α and dinoprost stimulated P4 secretion (P<0.05), whereas cloprostenol and luprostiol did not influence P4 synthesis. The greatest cytotoxic and pro-apoptotic effects were observed in the luprostiol-treated cells, at 37.3% and 202%, respectively (P<0.001). The greatest effect on [Ca(2+)]i mobilisation in luteal cells was observed post-luprostiol treatment (200%; P<0.001). In a second experiment, the influence of naturally-occurring PGF2α and aPGF2α on ovarian arterial contraction in vitro, were examined. No differences in the effects of dinoprost or naturally-occurring PGF2α were found across the studied parameters. The effects of cloprostenol and luprostiol on luteal cell death, in addition to their effects on ovarian arterial contractility, were much greater than those produced by treatment with naturally-occurring PGF2α.


Assuntos
Artérias/efeitos dos fármacos , Bovinos , Dinoprosta/análogos & derivados , Células Lúteas/efeitos dos fármacos , Ovário/irrigação sanguínea , Vasoconstrição/efeitos dos fármacos , Animais , Cloprostenol/farmacologia , Dinoprosta/farmacologia , Feminino , Células Lúteas/fisiologia , Prostaglandinas F Sintéticas/farmacologia
12.
Bioinspir Biomim ; 8(4): 045001, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24262846

RESUMO

We investigated the structural color of the green wing of the lycaenid butterfly Chrysozephyrus brillantinus. Electron microscopy revealed that the bottom plate of the cover scale on the wing consists of an alternating air-cuticle multilayer structure. However, the thicknesses of the layers were not constant but greatly differed depending on the layer, unlike the periodic multilayer designs often adopted for artificial laser-reflecting mirrors. The agreement between the experimentally determined and theoretically calculated reflectance spectra led us to conclude that the multilayer interference in the aperiodic system is the primary origin of the structural color. We analyzed optical interference in this aperiodic system using a simple analytical model and found that two spectral peaks arise from constructive interference among different parts of the multilayer structure. We discuss the advantages and disadvantages of the aperiodic system over a periodic one.


Assuntos
Borboletas/química , Borboletas/ultraestrutura , Cor , Modelos Anatômicos , Modelos Químicos , Asas de Animais/química , Asas de Animais/ultraestrutura , Animais , Simulação por Computador , Luz , Refratometria/métodos , Espalhamento de Radiação
13.
Leukemia ; 27(3): 619-28, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22948537

RESUMO

The BCR-ABL fusion oncoprotein accelerates differentiation and proliferation of myeloid cells during the chronic phase of chronic myeloid leukemia (CP-CML). Here, the role of CCAAT/enhancer binding protein ß (C/EBPß), a regulator for 'emergency granulopoiesis,' in the pathogenesis of CP-CML was examined. C/EBPß expression was upregulated in Lineage(-) CD34(+) CD38(-) hematopoietic stem cells (HSCs) and myeloid progenitors isolated from bone marrow of patients with CP-CML. In EML cells, a mouse HSC line, BCR-ABL upregulated C/EBPß, at least in part, through the activation of STAT5. Myeloid differentiation and proliferation induced by BCR-ABL was significantly impaired in C/EBPß-deficient bone marrow cells in vitro. Mice that were transplanted with BCR-ABL-transduced C/EBPß knockout bone marrow cells survived longer than mice that received BCR-ABL-transduced wild-type (WT) bone marrow cells. Significantly higher levels of leukemic stem cells were maintained in BCR-ABL-transduced C/EBPß-deficient cells than in BCR-ABL-transduced WT cells. These results suggest that C/EBPß is involved in BCR-ABL-mediated myeloid expansion. Further elucidation of the molecular mechanisms underlying the C/EBPß-mediated stem cell loss might reveal a novel therapeutic strategy for eradication of CML stem cells.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/fisiologia , Proteínas de Fusão bcr-abl/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Células Mieloides/patologia , Células-Tronco/patologia , Animais , Antígenos CD34/metabolismo , Western Blotting , Medula Óssea/metabolismo , Medula Óssea/patologia , Transplante de Medula Óssea , Diferenciação Celular , Proliferação de Células , Feminino , Citometria de Fluxo , Proteínas de Fusão bcr-abl/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Mieloides/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT5 , Células-Tronco/metabolismo
14.
Braz. j. med. biol. res ; 45(12): 1157-1162, Dec. 2012. ilus
Artigo em Inglês | LILACS | ID: lil-659648

RESUMO

Support structures for dermal regeneration are composed of biodegradable and bioresorbable polymers, animal skin or tendons, or are bacteria products. The use of such materials is controversial due to their low efficiency. An important area within tissue engineering is the application of multipotent mesenchymal stromal cells (MSCs) to reparative surgery. The combined use of biodegradable membranes with stem cell therapy may lead to promising results for patients undergoing unsuccessful conventional treatments. Thus, the aim of this study was to test the efficacy of using membranes composed of anionic collagen with or without the addition of hyaluronic acid (HA) as a substrate for adhesion and in vitro differentiation of bone marrow-derived canine MSCs. The benefit of basic fibroblast growth factor (bFGF) on the differentiation of cells in culture was also tested. MSCs were collected from dog bone marrow, isolated and grown on collagen scaffolds with or without HA. Cell viability, proliferation rate, and cellular toxicity were analyzed after 7 days. The cultured cells showed uniform growth and morphological characteristics of undifferentiated MSCs, which demonstrated that MSCs successfully adapted to the culture conditions established by collagen scaffolds with or without HA. This demonstrates that such scaffolds are promising for applications to tissue regeneration. bFGF significantly increased the proliferative rate of MSCs by 63% when compared to groups without the addition of the growth factor. However, the addition of bFGF becomes limiting, since it has an inhibitory effect at high concentrations in culture medium.


Assuntos
Animais , Cães , Colágeno/efeitos dos fármacos , Ácido Hialurônico/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Regeneração/efeitos dos fármacos , Técnicas de Cultura de Células , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Terapia Baseada em Transplante de Células e Tecidos/métodos , Colágeno/fisiologia , Citometria de Fluxo , Imuno-Histoquímica , Células-Tronco Mesenquimais/citologia , Engenharia Tecidual
15.
Braz J Med Biol Res ; 45(12): 1157-62, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22983182

RESUMO

Support structures for dermal regeneration are composed of biodegradable and bioresorbable polymers, animal skin or tendons, or are bacteria products. The use of such materials is controversial due to their low efficiency. An important area within tissue engineering is the application of multipotent mesenchymal stromal cells (MSCs) to reparative surgery. The combined use of biodegradable membranes with stem cell therapy may lead to promising results for patients undergoing unsuccessful conventional treatments. Thus, the aim of this study was to test the efficacy of using membranes composed of anionic collagen with or without the addition of hyaluronic acid (HA) as a substrate for adhesion and in vitro differentiation of bone marrow-derived canine MSCs. The benefit of basic fibroblast growth factor (bFGF) on the differentiation of cells in culture was also tested. MSCs were collected from dog bone marrow, isolated and grown on collagen scaffolds with or without HA. Cell viability, proliferation rate, and cellular toxicity were analyzed after 7 days. The cultured cells showed uniform growth and morphological characteristics of undifferentiated MSCs, which demonstrated that MSCs successfully adapted to the culture conditions established by collagen scaffolds with or without HA. This demonstrates that such scaffolds are promising for applications to tissue regeneration. bFGF significantly increased the proliferative rate of MSCs by 63% when compared to groups without the addition of the growth factor. However, the addition of bFGF becomes limiting, since it has an inhibitory effect at high concentrations in culture medium.


Assuntos
Colágeno/efeitos dos fármacos , Ácido Hialurônico/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Regeneração/efeitos dos fármacos , Animais , Técnicas de Cultura de Células , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Terapia Baseada em Transplante de Células e Tecidos/métodos , Colágeno/fisiologia , Cães , Citometria de Fluxo , Imuno-Histoquímica , Células-Tronco Mesenquimais/citologia , Engenharia Tecidual
17.
J Viral Hepat ; 19(2): e220-4, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22239522

RESUMO

Ischaemic colitis is known to be a severe emergency complication of interferon (IFN) therapy. However, as ischaemic colitis is an infrequent complication of IFN therapy, limited information is available regarding the safety of resuming IFN therapy after resolution of ischaemic colitis and subsequent recurrence. Here, we report two cases of ischaemic colitis during IFN therapy for chronic hepatitis C. Ischaemic colitis was fully healed within 1 week after its onset and IFN withdrawal, and IFN therapy was resumed following patients' wishes to do so. Ischaemic colitis did not recur after the resumption of IFN therapy, and sustained virological response was achieved in both patients. In this report, we also summarize the findings of 11 cases of IFN-associated ischaemic colitis (nine previously published cases plus our two cases) and review the clinical characteristics of ischaemic colitis during IFN therapy in patients with chronic hepatitis C.


Assuntos
Colite Isquêmica/induzido quimicamente , Hepatite C Crônica/tratamento farmacológico , Interferons/administração & dosagem , Interferons/efeitos adversos , Colite Isquêmica/patologia , Colonoscopia , Feminino , Histocitoquímica , Humanos , Fatores Imunológicos/administração & dosagem , Fatores Imunológicos/efeitos adversos , Microscopia , Pessoa de Meia-Idade , Resultado do Tratamento , Suspensão de Tratamento
18.
J R Soc Interface ; 8(54): 56-66, 2011 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-20554565

RESUMO

The structural colour of the neon tetra is distinguishable from those of, e.g., butterfly wings and bird feathers, because it can change in response to the light intensity of the surrounding environment. This fact clearly indicates the variability of the colour-producing microstructures. It has been known that an iridophore of the neon tetra contains a few stacks of periodically arranged light-reflecting platelets, which can cause multilayer optical interference phenomena. As a mechanism of the colour variability, the Venetian blind model has been proposed, in which the light-reflecting platelets are assumed to be tilted during colour change, resulting in a variation in the spacing between the platelets. In order to quantitatively evaluate the validity of this model, we have performed a detailed optical study of a single stack of platelets inside an iridophore. In particular, we have prepared a new optical system that can simultaneously measure both the spectrum and direction of the reflected light, which are expected to be closely related to each other in the Venetian blind model. The experimental results and detailed analysis are found to quantitatively verify the model.


Assuntos
Cor , Peixes/fisiologia , Modelos Biológicos , Animais , Peixes/anatomia & histologia , Luz , Microespectrofotometria , Óptica e Fotônica , Propriedades de Superfície
20.
Br J Cancer ; 100(10): 1647-58, 2009 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-19401692

RESUMO

Type I IFN receptor type 2 (IFNAR2) expression correlates significantly with clinical response to interferon (IFN)-alpha/5-fluorouracil (5-FU) combination therapy for hepatocellular carcinoma (HCC). However, some IFNAR2-positive patients show no response to the therapy. This result suggests the possibility of other factors, which would be responsible for resistance to IFN-alpha/5-FU therapy. The aim of this study was to examine the mechanism of anti-proliferative effects of IFN-alpha/5-FU therapy and search for a biological marker of chemoresistance to such therapy. Gene expression profiling and molecular network analysis were used in the analysis of non-responders and responders with IFNAR2-positive HCC. The Wnt/beta-catenin signalling pathway contributed to resistance to IFN-alpha/5-FU therapy. Immunohistochemical analysis showed positive epithelial cell adhesion molecule (Ep-CAM) expression, the target molecule of Wnt/beta-catenin signalling, only in non-responders. In vitro studies showed that activation of Wnt/beta-catenin signalling by glycogen synthesis kinase-3 inhibitor (6-bromoindirubin-3'-oxime (BIO)) induced chemoresistance to IFN-alpha/5-FU. BrdU-based cell proliferation ELISA and cell cycle analysis showed that concurrent addition of BIO and IFN-alpha/5-FU significantly to hepatoma cell cultures reduced the inhibitory effects of the latter two on DNA synthesis and accumulation of cells in the S-phase. The results indicate that activation of Wnt/beta-catenin signalling pathway induces chemoresistance to IFN-alpha/5-FU therapy and suggest that Ep-CAM is a potentially useful marker for resistance to such therapy, especially in IFNAR2-positive cases.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Hepáticas/tratamento farmacológico , Proteínas Wnt/fisiologia , beta Catenina/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/fisiologia , Carcinoma Hepatocelular/genética , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/fisiologia , Linhagem Celular Tumoral , Molécula de Adesão da Célula Epitelial , Feminino , Fluoruracila/administração & dosagem , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Interferon-alfa/administração & dosagem , Neoplasias Hepáticas/genética , Masculino , Pessoa de Meia-Idade , Mutação/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , Receptor de Interferon alfa e beta/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Proteínas Wnt/genética , beta Catenina/genética
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