Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Br J Dermatol ; 183(3): 524-536, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31794074

RESUMO

BACKGROUND: Eczema control has been identified as an important outcome by key stakeholders in eczema research (including patients, carers, healthcare professionals and researchers) but no validated instruments for the domain have been identified. OBJECTIVES: To develop a measurement instrument to capture a patient's perspective of eczema control that is suitable for use in eczema clinical trials. METHODS: Best practice for the development of a patient-reported outcome was followed. A mixed-methods approach was used to develop and refine a conceptual framework, generate, refine and select items and to test the distribution and construct validity of the final scale. The mixed-methods approach involved expert panel meetings (including patient representatives, healthcare professionals and methodologists), and data collection using a focus group, cognitive interviews and an online survey with people with eczema and caregivers. Multivariable linear regression was used in the item selection process. RESULTS: Fourteen expert panel members co-produced the instrument, with input from people with eczema and caregivers via a focus group (n = 6), cognitive interviews (n = 13) and an online survey (n = 330). The resulting instrument, Recap of atopic eczema (RECAP), is a seven-item questionnaire that captures eczema control via self or caregiver report. The development process aimed to ensure good content validity and feasibility. Initial testing suggested no floor or ceiling effects and good construct validity. Hypothesized correlation with the Patient-Oriented Eczema Measure was confirmed [r(258) = 0·83, P < 0·001]. CONCLUSIONS: RECAP has the potential to improve reporting of eczema control in research and clinical practice. Further exploration of measurement properties is required. Linked Comment: Pattinson and Bundy. Br J Dermatol 2020; 183:418-419. What's already known about this topic? Eczema control has been identified as an important outcome by key stakeholders in eczema research (including patients, carers, healthcare professionals and researchers). Qualitative studies suggest eczema control is a multifaceted and individual experience and no instrument has been identified that captures eczema control in this way. What does this study add? We have developed Recap of atopic eczema (RECAP), a seven-item questionnaire to capture the experience of eczema control in all ages and eczema severities; there are two versions: a self-reported version for adults and older children with eczema, and a caregiver-reported version for younger children with eczema. Designed with input from people with eczema, caregivers and healthcare professionals to ensure good content validity. Initial testing of score distributions and construct validity suggests good measurement properties. What are the clinical implications of the work? The RECAP instrument is appropriate and feasible for measuring eczema control in clinical trials and may also be useful in routine practice.


Assuntos
Dermatite Atópica , Eczema , Adolescente , Adulto , Cuidadores , Criança , Dermatite Atópica/prevenção & controle , Eczema/prevenção & controle , Humanos , Medidas de Resultados Relatados pelo Paciente , Inquéritos e Questionários
2.
Biochem Soc Trans ; 35(Pt 5): 1358-63, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17956351

RESUMO

Accumulating data suggest that dietary phytochemicals have the potential to moderate deregulated signalling or reinstate checkpoint pathways and apoptosis in damaged cells, while having minimal impact on healthy cells. These are ideal characteristics for chemopreventive and combination anticancer strategies, warranting substantial research effort into harnessing the biological activities of these agents in disease prevention and treatment. However, this requires further investigation into their mode of action and novel approaches to the development of reliable biomarkers.


Assuntos
Anticarcinógenos/farmacologia , Dieta , Neoplasias/prevenção & controle , Plantas/química , Biomarcadores Tumorais/metabolismo , Humanos , Neoplasias/metabolismo , Células-Tronco Neoplásicas/citologia , Fatores de Risco
3.
Apoptosis ; 11(5): 799-812, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16532375

RESUMO

Indole-3-carbinol (I3C) is a promising anticancer dietary compound, which inhibits breast cancer in animal models. The objective of the current study was to characterize I3C-induced cell death in a panel of human breast tumorigenic cells (MCF7, MDA-MB-468, MDA-MB-231 and HBL100) in comparison with normal fibroblasts. Since epithelial cells are protected from cell death by a three-dimensional environment, 3D cell culture (collagen I gel and spheroids) was employed to investigate susceptibility to I3C. Cell viability in the presence of 256 microM I3C, a concentration close to the physiologically achievable range, was in the order fibroblasts = HBL100>MDA-MB-231>MCF7>MDA-MB-468 in monolayer culture. However, 3D culture conditions increased the susceptibility of MCF7 and MDA-MB-468 cancer cells towards I3C. I3C induced cell death in breast cancer MCF7, MDA-MB-468 and MDA-MB-231 cells via the mitochondrial apoptotic pathway. I3C significantly reduced levels of epidermal growth factor receptor (EGFR) in MDA-MB-468 after 6 h and in MDA-MB-231 and HBL100 cells after 30 h. Downregulation of EGFR in MDA-MB468 and MDA-MB-231 cells using an EGFR inhibitor resulted in apoptosis. EGFR modulation using EGF or an EGFR inhibitor markedly influenced viability and response to I3C in MDA-MB-468 cells in 3D conditions. EGFR expression was modulated by 3D conditions. Therefore, I3C-induced EGFR reduction in these cells is likely to be responsible for I3C-induced apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Receptores ErbB/metabolismo , Antagonistas de Estrogênios/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Indóis/farmacologia , Trifosfato de Adenosina/análise , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Caspase 3 , Caspase 7 , Inibidores de Caspase , Caspases/metabolismo , Linhagem Celular , Linhagem Celular Transformada , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação para Baixo , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Feminino , Fibroblastos/efeitos dos fármacos , Humanos , Quinazolinas/farmacologia , Fatores de Tempo
4.
Curr Med Chem Anticancer Agents ; 5(3): 201-13, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15992350

RESUMO

There is great potential for the use of plant-derived agents in the fight to prevent onset or delay progression of the carcinogenic process. Epidemiological evidence for their chemopreventive action is compelling, but even though many of these compounds have an extensive history of use within the human populace, it is of increasing importance to determine more precisely the primary targets contributing to their efficacy, prior to embarking on large-scale clinical trials. This rapidly moving field now concentrates in particular, on the modulating effects these agents can have on cellular signalling pathways involved in the apoptotic, proliferative and angiogenic processes, perturbances to which, are common in many cancers. It is perhaps the ability of these agents to exhibit multi-site mechanisms of action that offers their key to success where conventional single-site agents have disappointed in the past. As well as being promising chemopreventive agents, there is also an exciting role for these compounds in combinatorial therapy with more traditional chemotherapeutics, potentially in lowering of toxicity and enhancing efficacy for treatment of more advanced cancers. This review will summarise known and proposed mechanisms of action for various chemopreventive agents of interest highlighting their potential in combination therapy, and will address benefits and problems of using such multi-site agents in long-term prevention/therapeutic regimes.


Assuntos
Anticarcinógenos , Neoplasias/prevenção & controle , Fitoterapia , Preparações de Plantas , Animais , Anticarcinógenos/química , Anticarcinógenos/farmacologia , Anticarcinógenos/uso terapêutico , Quimioprevenção , Humanos , Preparações de Plantas/química , Preparações de Plantas/farmacologia , Preparações de Plantas/uso terapêutico
5.
Br J Cancer ; 91(6): 1213-9, 2004 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-15292928

RESUMO

Quercetin (3,5,7,3',4'-pentahydroxyflavone) is a flavone with putative ability to prevent cancer and cardiovascular diseases. Its metabolism was evaluated in rats and human. Rats received quercetin via the intravenous (i.v.) route and metabolites were isolated from the plasma, urine and bile. Analysis was by high-performance liquid chromatography and confirmation of species identity was achieved by mass spectrometry. Quercetin and isorhamnetin, the 3'-O-methyl analogue, were found in both the plasma and urine. In addition, several polar peaks were characterised as sulphated and glucuronidated conjugates of quercetin and isorhamnetin. Extension of the metabolism studies to a cancer patient who had received quercetin as an i.v. bolus showed that (Quercetin removed) isorhamnetin and quercetin 3'-O-sulphate were major plasma metabolites. As a catechol, quercetin can potentially be converted to a quinone and subsequently conjugated with glutathione (GSH). Oxidation of quercetin with mushroom tyrosinase in the presence of GSH furnished GSH conjugates of quercetin, two mono- and one bis-substituted conjugates. However, these species were not found in biomatrices in rats treated with quercetin. As cyclo-oxygenase-2 (COX-2) expression is mechanistically linked to carcinogenesis, we examined whether quercetin and its metabolites can inhibit COX-2 in a human colorectal cancer cell line (HCA-7). Isorhamnetin and its 4'-isomer tamarixetin were potent inhibitors, reflected in a 90% decrease in prostaglandin E-2 (PGE-2) levels, a marker of COX-2 activity. Quercetin was less effective, with a 50% decline. Quercetin 3- and 7-O-sulphate had no effect on PGE-2. The results indicate that quercetin may exert its pharmacological effects, at least in part, via its metabolites.


Assuntos
Prostaglandina-Endoperóxido Sintases/metabolismo , Quercetina/farmacologia , Animais , Anticarcinógenos/sangue , Anticarcinógenos/farmacocinética , Anticarcinógenos/farmacologia , Transporte Biológico , Cromatografia Líquida de Alta Pressão , Dinoprostona/metabolismo , Humanos , Masculino , Quercetina/sangue , Quercetina/farmacocinética , Ratos , Ratos Endogâmicos F344
6.
Br J Cancer ; 85(4): 618-24, 2001 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-11506505

RESUMO

Genistein is thought to contribute to the putative breast cancer preventive activity of soya. The mechanisms by which it arrests the growth of breast cells are incompletely understood. In order to explore generic features of the modulation of human breast cell growth by genistein, its effects on cell lines MCF-7, ZR-75.1, T47-D, MDA-MB 468, MDA-MB 231 and HBL 100 were compared. Genistein at 1 microM stimulated growth only in MCF-7 cells. At 10 microM it arrested the growth of all 6 cell types, however that of T47-D and HBL 100 cells only in medium with reduced (2%) fetal calf serum. Genistein induced apoptosis in only MDA-MB 468 cells. It arrested cells in the G2 stage of the cell cycle in all cell lines except ZR-75.1. Cells differed in their susceptibility towards inhibition by genistein of phorbol ester-induced proto-oncogene c-fos levels, transcription factor activator protein-1 (AP-1) activity and extracellular signal-regulated kinase (ERK) activity. Genistein augmented anisomycin-induced levels of proto-oncogene c-jun in ZR 75.1 and MCF-7 cells. The results suggest that induction of apoptosis, G2 cell cycle arrest and inhibition of c-fos expression, AP-1 transactivation and ERK phosphorylation may contribute to the growth-inhibitory effect of genistein in some breast cell types, but none of these effects of genistein constitutes a generic mode of growth-arresting action.


Assuntos
Anticarcinógenos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Genisteína/farmacologia , Ciclo Celular , Quimioprevenção , Feminino , Humanos , Proteínas Quinases Ativadas por Mitógeno/biossíntese , Proteínas Quinases Ativadas por Mitógeno/farmacologia , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-fos/biossíntese , Proteínas Proto-Oncogênicas c-fos/farmacologia , Transdução de Sinais , Glycine max , Fator de Transcrição AP-1/biossíntese , Fator de Transcrição AP-1/farmacologia , Células Tumorais Cultivadas
7.
Biochem Soc Trans ; 28(2): 7-12, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10816090

RESUMO

For a disease such as cancer, where a number of alterations to normal cell function accumulate over time, there are several opportunities to inhibit, slow down or even reverse the process. Many of the changes which drive the disease process occur in cell-signalling pathways that regulate proliferation and apoptosis. As our knowledge of these complicated signalling networks improves, it is becoming clear that many molecules, both drugs and naturally occurring dietary constituents, can interact beneficially with deregulated pathways. Aspirin and other non-steroidal anti-inflammatory drugs, as well as natural compounds present in plants such as green vegetables and tea, can modulate signalling by affecting kinase activity and therefore phosphorylation of key molecules. Examples of pathways which can be modulated by these agents include activation of the transcription factor nuclear factor kappaB by tumour promoters or cytokines, signalling by growth factors through the growth-factor receptor/extracellular-regulated protein kinase pathways and by a number of other molecules through the stress-activated c-Jun N-terminal kinase and p38 pathways. These mitogen-activated protein kinase pathways regulate a number of transcription factors including c-Fos and c-Jun. Evidence exists, at least from in vitro experiments, that by targeting such pathways, certain dietary compounds may be able to restore abnormal rates of apoptosis and proliferation to more normal levels.


Assuntos
Anticarcinógenos/farmacologia , Transdução de Sinais , Animais , Apoptose , Ciclo Celular , Divisão Celular , Linhagem Celular , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos , Modelos Biológicos , NF-kappa B/metabolismo , Receptores de Fatores de Crescimento/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...