Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 132
Filtrar
1.
Gynecol Oncol Rep ; 48: 101220, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37434947

RESUMO

The Lynch syndrome (LS) is an autosomal dominant condition usually characterized by germline pathogenic variants in DNA mismatch repair (MMR) genes. Despite the guidelines now available, determining the pathogenicity of rare variants remains challenging, as the clinical significance of a genetic variant could be uncertain, but it may represent a disease-associated variation in the aforementioned genes. In this case report we will describe the case of a 47 years-old female affected by endometrial cancer (EC) with an extremely rare germline heterozygous variant in the MSH2 gene (c.562G > T p. (Glu188Ter), exon 3) that is likely pathogenic, and a family history consistent with LS.

2.
Bioinspir Biomim ; 18(1)2022 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-36322994

RESUMO

Oscillatory swimming of a fishlike body, whose motion is essentially promoted by the flapping tail, has been studied almost exclusively in axial mode under an incoming uniform stream or, more recently, self-propelled under a virtual body resistance. Obviously, both approaches do not consider the unavoidable recoil motions of the real body which have to be necessarily accounted for in a design procedure for technological means. Actually, once combined with the prescribed kinematics of the tail, the recoil motions lead to a remarkable improvement on the resulting swimming performance. An inviscid impulse model, linear in both potential and vortical contributions, is a proper tool to obtain a deeper comprehension of the physical events with respect to more elaborated flow interaction models. In fact, at a first look, the numerical results seem to be quite entangled, since their trends in terms of the main flapping parameters are not easy to be identified and a fair interpretation is obtained by means of the model capability to separate the effects of added mass and vortex shedding. Specifically, a prevailing dependence of the potential contribution on the heave amplitude and of the vortical contribution on the pitch amplitude is instrumental to unravel their combined action. A further aid for a proper interpretation of the data is provided by accounting separately for a geometrical component of the recoil which is expected to follow from the annihilation of any spurious rigid motion in case no fluid interactions occur. The above detailed decomposition of the recoil motions shows, through the numerical results, how the single components are going to influence the main flapping parameters and the locomotion performance as a guide for the design of biomimetic swimmers.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Natação , Humanos , Locomoção , Biomimética , Movimento (Física)
3.
Leukemia ; 31(9): 1882-1893, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28017968

RESUMO

Even if NOTCH1 is commonly mutated in chronic lymphocytic leukemia (CLL), its functional impact in the disease remains unclear. Using CRISPR/Cas9-generated Mec-1 cell line models, we show that NOTCH1 regulates growth and homing of CLL cells by dictating expression levels of the tumor suppressor gene DUSP22. Specifically, NOTCH1 affects the methylation of DUSP22 promoter by modulating a nuclear complex, which tunes the activity of DNA methyltransferase 3A (DNMT3A). These effects are enhanced by PEST-domain mutations, which stabilize the molecule and prolong signaling. CLL patients with a NOTCH1-mutated clone showed low levels of DUSP22 and active chemotaxis to CCL19. Lastly, in xenograft models, NOTCH1-mutated cells displayed a unique homing behavior, localizing preferentially to the spleen and brain. These findings connect NOTCH1, DUSP22, and CCL19-driven chemotaxis within a single functional network, suggesting that modulation of the homing process may provide a relevant contribution to the unfavorable prognosis associated with NOTCH1 mutations in CLL.


Assuntos
Quimiocina CCL19/fisiologia , Fosfatases de Especificidade Dupla/genética , Leucemia Linfocítica Crônica de Células B/patologia , Fosfatases da Proteína Quinase Ativada por Mitógeno/genética , Receptor Notch1/genética , Linhagem Celular , Movimento Celular , Quimiotaxia , DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA Metiltransferase 3A , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Xenoenxertos , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Mutação , Domínios Proteicos/genética
4.
Scanning ; 37(5): 372-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25940790

RESUMO

The purpose of this study is to evaluate the efficacy of yttria-stabilized zirconia (3Y-TZP) as an inert phase to prevent the decomposition of Bi2 V0.9 Cu0.1 O5.5 -δ (BICUVOX.1) electrolyte under reducing atmosphere. A post-mortem scanning electron microscopy (SEM) study was performed after chemical stability tests under hydrogen-rich atmosphere using a Sieverts-type apparatus. SEM results showed that BICUVOX.1 decomposition starts under a hydrogen pressure of 19.7 atm at 300°C, even in the case of the composite containing 3Y-TZP. The microstructure of BICUVOX.1 after decomposition was observed to be composed of microspheres ranging from 10 to 100 µm formed primarily of metallic bismuth. In the composite, in addition to microspheres, the microstructure contained bismuth fibers growth from the grain area of the BICUVOX.1 matrix. Despite significant surface morphological modifications, the grain-boundary-arranged 3Y-TZP particles in a BICUVOX.1-matrix composite did not result in enhanced chemical stability.

5.
Osteoarthritis Cartilage ; 23(7): 1226-30, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25797039

RESUMO

OBJECTIVE: To contribute to clarify molecular mechanisms supporting senescence and de-differentiation of chondrocytes in chondrocyte pathologies such as osteoarthritis (OA). Specifically, we investigated the relationship between the nuclear lamina protein Lamin B1 and the negative regulator of chondrogenesis Slug transcription factor in osteoarthritic chondrocytes. METHODS: Lamin B1 and Slug proteins were analyzed in cartilage explants from normal subjects and OA patients by immunohistochemical technique. Their expression was confirmed on isolated chondrocytes both at passage 0 and passage 2 (de-differentiated chondrocytes) by immunofluorescence and western blot. Subsequently, we explored the "in vivo" binding of Slug on LMNB1 promoter by chromatin immunoprecipitation assay (ChIP). RESULTS: In this study we demonstrated that nuclear lamina protein Lamin B1 and anti-chondrogenic Slug transcription factor are upregulated in cartilage and OA chondrocytes. Furthermore, we found that Slug is "in vivo" recruited by LMNB1 gene promoter mostly when chondrocytes undergo de-differentiation or OA degeneration. CONCLUSIONS: We described for the first time a potential regulatory role of Slug on the LMNB1 gene expression in OA chondrocytes. These findings may have important implications for the study of premature senescence, and degeneration of cartilage, and may contribute to develop effective therapeutic strategies against signals supporting cartilage damage in different subsets of patients.


Assuntos
Condrócitos/metabolismo , Laminina/biossíntese , Osteoartrite do Joelho/metabolismo , Fatores de Transcrição/biossíntese , Idoso , Cartilagem Articular/metabolismo , Núcleo Celular/metabolismo , Células Cultivadas , Feminino , Humanos , Articulação do Joelho/metabolismo , Laminina/genética , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/genética , Fatores de Transcrição da Família Snail , Fatores de Transcrição/genética , Regulação para Cima
7.
J Periodontal Res ; 50(4): 544-53, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25251713

RESUMO

BACKGROUND AND OBJECTIVE: Bioreactors are devices that efficiently create an environment that enables cell cultures to grow in a three-dimensional (3D) context mimicking in vivo conditions. In this study, we investigate the effect of dynamic fluid flow on the osteogenic potential of human mesenchymal stem cells obtained from periodontal ligament and entrapped in alginate microbeads. MATERIAL AND METHODS: After proper immunophenotyping, cells were encapsulated in barium alginate, cultured in 3D static or 3D dynamic conditions represented by a bioreactor system. Calcein-AM/propidium iodide staining was used to assess cellular viability. Quantitative real-time polymerase chain reaction was used to analyze the expression of osteogenic markers (Runx2 and COL1). Alizarin Red S staining and the Fourier transform infrared spectroscopy were used to assess mineral matrix deposition. RESULTS: Optimal encapsulation procedure, in terms of polymer pumping rate, distance from droplet generator to the gelling bath and atomizing airflow was assessed. Cell viability was not affected by encapsulation in alginate microbeads. Bioreactor cell exposure was effective in anticipating osteogenic differentiation and improving mineral matrix deposition. CONCLUSION: For the first time human mesenchymal stem cells obtained from periodontal ligaments encapsulated in alginate microbeads were cultured in a bioreactor system. This combination could represent a promising strategy to create a cell-based smart system with enhanced osteogenic potential useful for many different dental applications.


Assuntos
Alginatos , Materiais Biocompatíveis , Células-Tronco Mesenquimais/fisiologia , Osteogênese/fisiologia , Ligamento Periodontal/citologia , Alicerces Teciduais , Adipogenia/fisiologia , Alginatos/química , Apatitas/análise , Materiais Biocompatíveis/química , Reatores Biológicos , Técnicas de Cultura de Células , Diferenciação Celular/fisiologia , Sobrevivência Celular/fisiologia , Condrogênese/fisiologia , Colágeno Tipo I/análise , Cadeia alfa 1 do Colágeno Tipo I , Subunidade alfa 1 de Fator de Ligação ao Core/análise , Matriz Extracelular/química , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Humanos , Hidrodinâmica , Microesferas , Propriedades de Superfície , Alicerces Teciduais/química , Geleia de Wharton/citologia
8.
Leukemia ; 29(6): 1390-401, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25533804

RESUMO

Although anaplastic large-cell lymphomas (ALCL) carrying anaplastic lymphoma kinase (ALK) have a relatively good prognosis, aggressive forms exist. We have identified a novel translocation, causing the fusion of the TRAF1 and ALK genes, in one patient who presented with a leukemic ALK+ ALCL (ALCL-11). To uncover the mechanisms leading to high-grade ALCL, we developed a human patient-derived tumorgraft (hPDT) line. Molecular characterization of primary and PDT cells demonstrated the activation of ALK and nuclear factor kB (NFkB) pathways. Genomic studies of ALCL-11 showed the TP53 loss and the in vivo subclonal expansion of lymphoma cells, lacking PRDM1/Blimp1 and carrying c-MYC gene amplification. The treatment with proteasome inhibitors of TRAF1-ALK cells led to the downregulation of p50/p52 and lymphoma growth inhibition. Moreover, a NFkB gene set classifier stratified ALCL in distinct subsets with different clinical outcome. Although a selective ALK inhibitor (CEP28122) resulted in a significant clinical response of hPDT mice, nevertheless the disease could not be eradicated. These data indicate that the activation of NFkB signaling contributes to the neoplastic phenotype of TRAF1-ALK ALCL. ALCL hPDTs are invaluable tools to validate the role of druggable molecules, predict therapeutic responses and implement patient specific therapies.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Linfoma Anaplásico de Células Grandes/genética , NF-kappa B/metabolismo , Receptores Proteína Tirosina Quinases/genética , Fator 1 Associado a Receptor de TNF/genética , Translocação Genética/genética , Quinase do Linfoma Anaplásico , Animais , Western Blotting , Citometria de Fluxo , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunoprecipitação , Hibridização in Situ Fluorescente , Linfoma Anaplásico de Células Grandes/tratamento farmacológico , Linfoma Anaplásico de Células Grandes/mortalidade , Camundongos , Camundongos Endogâmicos NOD , NF-kappa B/genética , Fator 1 de Ligação ao Domínio I Regulador Positivo , Inibidores de Proteassoma/farmacologia , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores Proteína Tirosina Quinases/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Fator 1 Associado a Receptor de TNF/metabolismo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Int J Pharm ; 440(2): 195-206, 2013 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-22884778

RESUMO

The current paper reports the production of polymeric micelles (PMs), based on pluronic block-copolymers, as drug carriers, precisely controlling the cellular delivery of drugs with various physico-chemical characteristics. PMs were produced with a microfluidic platform to exploit further control on the size characteristic of the PMs. PMs were designed for the co-delivery of dexamethasone (Dex) and ascorbyl-palmitate (AP) to in vitro cultured human periodontal ligament mesenchymal stem cells (hPDLSCs) for the combined induction of osteogenic differentiation. Mixtures of block-copolymers and drugs in organic, water miscible solvent, were conveniently converted in PMs within microfluidic channel leveraging the fast mixing at the microscale. Our results demonstrated that the drugs can be efficiently co-encapsulated in PMs and that different production parameters can be adjusted in order to modulate the PM characteristics. The comparative analysis of PM produced by microfluidic and conventional procedures confirmed that the use of microfluidics platforms allowed the production of PMs in a robust manner with improved controllability, reproducibility, smaller size and polydispersity. Finally, the analysis of the effect of PMs, containing Dex and AP, on the osteogenic differentiation of hPDLSCs is reported. The data demonstrated the effectiveness and safety of PM treatment on hPDLSC. In conclusion, this report indicates that microfluidic approach represents an innovative and useful method for PM controlled preparation, warrant further evaluation as general methodology for the production of colloidal systems for the simultaneous drug delivery.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Micelas , Microfluídica/métodos , Osteogênese/efeitos dos fármacos , Polímeros/farmacologia , Ácido Ascórbico/administração & dosagem , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Dexametasona/administração & dosagem , Dexametasona/farmacologia , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/farmacologia , Composição de Medicamentos/métodos , Humanos , Células-Tronco Mesenquimais/fisiologia , Microfluídica/instrumentação , Tamanho da Partícula , Ligamento Periodontal/citologia , Polímeros/administração & dosagem
10.
Rhinology ; 49(2): 148-54, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21743868

RESUMO

BACKGROUND: The research addressed to detect new molecular targets in the development of therapeutic strategies aimed to repair bone tissues. The AIM OF THIS STUDY was to determine the potential osteogenic activity of bone cells from the nasal septum and their use to perform accurate molecular analysis from a single sample. METHODOLOGY: The cells, after nasal septum surgery, were subjected to gene silencing, Reverse Transcriptase - Polymerase Chain reactions, immunocytochemistry and chromatin immunoprecipitation. RESULTS: Cells from the nasal septum can give rise to mature osteoblasts that express osteogenic markers (ALP, Runx2, Slug) and are able to mineralize. We demonstrated that Runx2, a transcription factor critical in early osteospecific differentiation, interacts in vivo with the promoter of the SLUG gene, a marker of osteoblast maturation. CONCLUSIONS: We demonstrated that nasal septum-derived osteoblasts represent an interesting alternative source for bone forming cells, and a promising material to be utilized in bone cellular therapy.


Assuntos
Septo Nasal/citologia , Osteogênese/fisiologia , Engenharia Tecidual/métodos , Adulto , Idoso , Imunoprecipitação da Cromatina , Subunidade alfa 1 de Fator de Ligação ao Core , Feminino , Citometria de Fluxo , Inativação Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Osteoblastos/fisiologia , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição da Família Snail , Fatores de Transcrição , Transfecção
11.
Minerva Stomatol ; 59(3): 103-15, 2010 Mar.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-20357737

RESUMO

The present study evaluated human primary osteoblasts and two different osteoblast-like cell lines behaviour when cultured in presence of different hydroxyapatite-based (HA) biomaterials (SINTlife-FIN-CERAMICA S.p.a., Faenza, Italy; Bio-Oss, Geistlich Biomaterials, Woulhusen, Switzerland; Biostite-GABA Vebas, San Giuliano Milanese, MI, Italy), focusing attention on the effect of HA/Biostite in terms of modulation of osteoblastic differentiation. Analysis were about adhesion, proliferation and mineralization activity. Runt-related transcription factor 2 (Runx2), Estrogen Receptor alpha (ERalfa) expression and alkaline phosphatase activity (ALP) were measured as osteoblastic differentiation markers. Determination of viable cells was done with MTT colorimetric assay. Scanning electron microscopy (SEM) analysis was performed on biomaterial-treated cells. All hydroxyapatite-based biomaterials didn't affect cells morphology and viability, whereas only presence of HA/Biostite improved cells adhesion, growth and differentiation. Adhesion and spreading of the primary cells on HA/Biostite were the same showed by two different osteoblast-like cell lines. These results have important implications for both tissue-engineered bone grafts and enhancement of HA implants performance, to develop new teeth's supporting structure therapies and replacement.


Assuntos
Materiais Biocompatíveis/farmacologia , Durapatita/farmacologia , Osteoblastos/efeitos dos fármacos , Células Cultivadas , Humanos , Fenótipo
13.
Leukemia ; 24(1): 187-96, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19924145

RESUMO

Nuclear factor-kappaB (NF-kappaB) is involved in multiple aspects of oncogenesis and controls cancer cell survival by promoting anti-apoptotic gene expression. The constitutive activation of NF-kappaB in several types of cancers, including hematological malignancies, has been implicated in the resistance to chemo- and radiation therapy. We have previously reported that cytokine- or virus-induced NF-kappaB activation is inhibited by chemical and physical inducers of the heat shock response (HSR). In this study we show that heat stress inhibits constitutive NF-kappaB DNA-binding activity in different types of B-cell malignancies, including multiple myeloma, activated B-cell-like (ABC) type of diffuse large B-cell lymphoma (DLBCL) and Burkitt's lymphoma presenting aberrant NF-kappaB regulation. Heat-induced NF-kappaB inhibition leads to rapid downregulation of the anti-apoptotic protein cellular inhibitor-of-apoptosis protein 2 (cIAP-2), followed by activation of caspase-3 and cleavage of the caspase-3 substrate poly(adenosine diphosphate ribose)polymerase (PARP), causing massive apoptosis under conditions that do not affect viability in cells not presenting NF-kappaB aberrations. NF-kappaB inhibition by the proteasome inhibitor bortezomib and by short-hairpin RNA (shRNA) interference results in increased sensitivity of HS-Sultan B-cell lymphoma to hyperthermic stress. Altogether, the results indicate that aggressive B-cell malignancies presenting constitutive NF-kappaB activity are sensitive to heat-induced apoptosis, and suggest that aberrant NF-kappaB regulation may be a marker of heat stress sensitivity in cancer cells.


Assuntos
Apoptose , Resposta ao Choque Térmico , Linfoma de Células B/patologia , NF-kappa B/antagonistas & inibidores , Transdução de Sinais/fisiologia , Proteína 3 com Repetições IAP de Baculovírus , Ácidos Borônicos/farmacologia , Bortezomib , Linhagem Celular Tumoral , DNA/metabolismo , Proteínas de Ligação a DNA/fisiologia , Fatores de Transcrição de Choque Térmico , Temperatura Alta , Humanos , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Linfoma de Células B/metabolismo , Biossíntese de Proteínas , Pirazinas/farmacologia , Fator de Transcrição RelA/antagonistas & inibidores , Fatores de Transcrição/fisiologia , Ubiquitina-Proteína Ligases
14.
Leukemia ; 23(11): 2102-8, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19626047

RESUMO

STAT1 and STAT3 are the main mediators of the signaling of interferons (IFNs) and of gp130 cytokines, respectively. Neoplastic T lymphocytes frequently become resistant to the IFN-gamma/STAT1 apoptotic pathway, often because of the downregulation of the IFN-gammaR2 receptor chain. Many studies suggest that cross-regulation between different STATs, in particular between STAT1 and STAT3, may profoundly affect cytokine/growth factor signaling. Here, the function of STAT3 in the negative regulation of STAT1 apoptotic pathway was investigated by RNA interference-mediated STAT3 silencing in human malignant T lymphocytes. In STAT3-depleted cells, interleukin (IL)-6 acquired the capacity to induce apoptosis, correlating with prolonged STAT1 activation and the induction of major histocompatibility complex (MHC) class I expression. In contrast, in the absence of STAT3, IFN-gamma could slightly enhance apoptosis but its ability to induce MHC class I expression was unchanged. Accordingly, IL-6, but not IFN-gamma, could significantly impair the in vivo growth of STAT3-depleted human neoplastic T lymphocytes transplanted into severe combined immunodeficient mice. Therefore, treatment with IL-6 and simultaneous STAT3 silencing may represent a potential therapeutic approach to control the expansion of IFN-gamma-unresponsive neoplastic T cells.


Assuntos
Interferon gama/metabolismo , Interleucina-6/metabolismo , Linfoma de Células T/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Fator de Transcrição STAT3/metabolismo , Linfócitos T/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Genes MHC Classe I/fisiologia , Humanos , Interferon gama/farmacologia , Interleucina-6/farmacologia , Linfoma de Células T/patologia , Camundongos , Camundongos SCID , Transplante de Neoplasias , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , RNA Interferente Pequeno , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT3/genética , Transdução de Sinais/fisiologia , Linfócitos T/citologia
15.
Eur Arch Otorhinolaryngol ; 265(1): 17-20, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17934745

RESUMO

There is a rising interest in the field of oncology in order to understand if cancer stem cells can play a key role also in the pathogenesis of head and neck tumors. It is likely that cancer stem cells are a minor population of tumor cells that possess the stem cell property of self-renewal. In addition, dysregulation of stem cell self-renewal is a likely requirement for the development of cancer. This new model for cancer will have significant ramifications for the way we will study and treat tumors. The authors are proposing a discussion of this topic, which, in their opinion, need to be further investigated in the ENT field.


Assuntos
Neoplasias de Cabeça e Pescoço/fisiopatologia , Células-Tronco Neoplásicas/fisiologia , Humanos
16.
Phys Rev Lett ; 97(14): 144509, 2006 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-17155263

RESUMO

The persistence of ratchet effects, i.e., nonzero mass flux under a zero-mean time-dependent drive, when many-body interactions are present, is studied via molecular dynamics (MD) simulations of a simple liquid flowing in an asymmetric nanopore. The results show that (i) ratchet effects persist under many-body density correlations induced by the forcing; (ii) two distinct linear responses (flux proportional to the drive amplitude) appear under strong loads. One regime has the same conductivity of linear response theory up to a forcing of about 10 kT, while the second displays a smaller conductivity, the difference in responses is due to geometric effects alone. (iii) Langevin simulations based on a naive mapping of the many-body equilibrium bulk diffusivity, D, onto the damping rate, gamma are also found to yield two distinct linear responses. However, in both regimes, the flux is significantly smaller than the one of MD simulations.


Assuntos
Modelos Químicos , Nanoestruturas/química , Simulação por Computador , Entropia , Canais Iônicos/química , Termodinâmica
17.
Apoptosis ; 10(5): 1079-94, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16151641

RESUMO

In this paper we investigated how the increase of human estrogen receptor alfa (ERalpha) gene expression may affect breast, osteoblast and osteoclast cells. Increase of ERalpha expression was obtained by interfering with the activity of a negative transcription factor and by removing it with a short and powerful decoy oligonucleotide (RA4-3') mimicking a region of distal promoter C of ERalpha gene. We provide evidence that this decoy was able to induce apoptosis in osteoclasts, but not in osteoblasts and in breast cancer cells, in an estrogen dependent manner. This effect was associated with increase of the levels of Caspase 3 and Fas receptor. Since ERalpha is important in the transcription of different genes and is involved in several pathological processes, including neoplastic and osteopenic diseases, our findings may be of relevance for a possible new therapeutical approach of such diseases.


Assuntos
Apoptose/fisiologia , Receptor alfa de Estrogênio/genética , Osteoclastos/citologia , Fatores de Transcrição/farmacologia , Apoptose/efeitos dos fármacos , Sequência de Bases , Neoplasias da Mama/metabolismo , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Células Cultivadas , Estradiol/farmacologia , Receptor alfa de Estrogênio/biossíntese , Humanos , Marcação In Situ das Extremidades Cortadas , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos/farmacologia , Osteoblastos/metabolismo , Osteoclastos/efeitos dos fármacos , Osteoclastos/fisiologia , Regiões Promotoras Genéticas , Transfecção
18.
Phys Rev Lett ; 95(2): 024503, 2005 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-16090687

RESUMO

In large Reynolds number turbulence, isotropy is recovered as the scale is reduced and homogeneous-isotropic scalings are eventually observed. This picture is violated in many cases, e.g., wall bounded flows, where, due to the shear, different scaling laws emerge. This effect has been ascribed to the contamination of the inertial range by the larger anisotropic scales. The issue is addressed here by analyzing both numerical and experimental data for a homogeneous shear flow. In fact, under strong shear, the alteration of the scaling exponents is not induced by the contamination from the anisotropic sectors. Actually, the exponents are universal properties of the isotropic component of the structure functions of shear dominated flows. The implications are discussed in the context of turbulence near solid walls, where improved closure models would be advisable.

19.
Curr Drug Targets ; 5(8): 735-44, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15578953

RESUMO

Peptide nucleic acids (PNAs)-DNA chimeras have been recently described as DNA mimics constituted of a part of PNA and of a part of DNA. We have demonstrated that double stranded molecules based on PNA-DNA chimeras bind to transcription factors in a sequence-dependent manner. Accordingly, these molecules can be used for transcription factor decoy (TFD) pharmacotherapy. Effects of double stranded PNA-DNA chimeras targeting NF-kappaB and Sp1 were determined on in vitro cultured human cells and were found to be comparable to those observed using double-stranded DNA decoys. The TFD molecules based on PNA-DNA chimeras can be further engineered by addition of short peptides facilitating cell penetration and nuclear localization. Therefore, these engineered molecules could be of great interest for in vivo experiments for non-viral gene therapy of a variety of diseases, including neoplastic and viral diseases, for which the TFD approach has been already demonstrated as a very useful strategy.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Oligodesoxirribonucleotídeos/farmacologia , Ácidos Nucleicos Peptídicos/farmacologia , Fatores de Transcrição/metabolismo , Apoptose , Células Cultivadas , Dicroísmo Circular , DNA/farmacologia , Terapia Genética , Humanos , NF-kappa B/genética
20.
Phytomedicine ; 10(4): 300-8, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12809360

RESUMO

In the present paper we show that extracts from Aegle marmelos Correa are able to inhibit the in vitro proliferation of human tumor cell lines, including the leukemic K562, T-lymphoid Jurkat, B-lymphoid Raji, erythroleukemic HEL, melanoma Colo38, and breast cancer MCF7 and MDA-MB-231 cell lines. Molecules present within the studied Aegle marmelos C. extracts were identified by gas-chromatography/mass-spectrometry analysis; three derivatives (butyl p-tolyl sulfide, 6-methyl-4-chromanone and butylated hydroxyanisole) were found to exhibit strong activity in inhibiting in vitro cell growth of human K562 cells. The antiproliferative activity of these compounds was found to be comparable to that of known antitumor agents, including cisplatin, chromomycin, cytosine arabinoside and 5-fluorouracil. In addition, the antiproliferative activity of butyl-p-tolyl sulfide, 6-methyl-4-chromanone and 5-methoxypsolaren was associated to activation of the differentiation pattern of K562 cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Fitoterapia , Extratos Vegetais/farmacologia , Rutaceae , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/uso terapêutico , Divisão Celular/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Concentração Inibidora 50 , Casca de Planta , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA