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2.
BMC Med Res Methodol ; 21(1): 103, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33975550

RESUMO

BACKGROUND: Practical methods for facilitating process improvement are needed to support high quality, safe care. How best to specify (identify and define) process improvements - the changes that need to be made in a healthcare process - remains a key question. Methods for doing so collaboratively, rapidly and remotely offer much potential, but are under-developed. We propose an approach for engaging diverse stakeholders remotely in a consensus-building exercise to help specify improvements in a healthcare process, and we illustrate the approach in a case study. METHODS: Organised in a five-step framework, our proposed approach is informed by a participatory ethos, crowdsourcing and consensus-building methods: (1) define scope and objective of the process improvement; (2) produce a draft or prototype of the proposed process improvement specification; (3) identify participant recruitment strategy; (4) design and conduct a remote consensus-building exercise; (5) produce a final specification of the process improvement in light of learning from the exercise. We tested the approach in a case study that sought to specify process improvements for the management of obstetric emergencies during the COVID-19 pandemic. We used a brief video showing a process for managing a post-partum haemorrhage in women with COVID-19 to elicit recommendations on how the process could be improved. Two Delphi rounds were then conducted to reach consensus. RESULTS: We gathered views from 105 participants, with a background in maternity care (n = 36), infection prevention and control (n = 17), or human factors (n = 52). The participants initially generated 818 recommendations for how to improve the process illustrated in the video, which we synthesised into a set of 22 recommendations. The consensus-building exercise yielded a final set of 16 recommendations. These were used to inform the specification of process improvements for managing the obstetric emergency and develop supporting resources, including an updated video. CONCLUSIONS: The proposed methodological approach enabled the expertise and ingenuity of diverse stakeholders to be captured and mobilised to specify process improvements in an area of pressing service need. This approach has the potential to address current challenges in process improvement, but will require further evaluation.


Assuntos
COVID-19 , Serviços de Saúde Materna , Consenso , Atenção à Saúde , Técnica Delphi , Feminino , Humanos , Pandemias , Gravidez , SARS-CoV-2
3.
Clin Cancer Res ; 14(14): 4437-45, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18628457

RESUMO

PURPOSE: Mutations in the receptor tyrosine kinase FLT3 are found in up to 30% of acute myelogenous leukemia patients and are associated with an inferior prognosis. In this study, we characterized critical tyrosine residues responsible for the transforming potential of active FLT3-receptor mutants and ligand-dependent activation of FLT3-WT. EXPERIMENTAL DESIGN: We performed a detailed structure-function analysis of putative autophosphorylation tyrosine residues in the FLT3-D835Y tyrosine kinase domain (TKD) mutant. All tyrosine residues in the juxtamembrane domain (Y566, Y572, Y589, Y591, Y597, and Y599), interkinase domain (Y726 and Y768), and COOH-terminal domain (Y955 and Y969) of the FLT3-D835Y construct were successively mutated to phenylalanine and the transforming activity of these mutants was analyzed in interleukin-3-dependent Ba/F3 cells. Tyrosine residues critical for the transforming potential of FLT3-D835Y were also analyzed in FLT3 internal tandem duplication mutants (FLT3-ITD)and the FLT3 wild-type (FLT3-WT) receptor. RESULT: The substitution of the tyrosine residues by phenylalanine in the juxtamembrane, interkinase, and COOH-terminal domains resulted in a complete loss of the transforming potential of FLT3-D835Y-expressing cells which can be attributed to a significant reduction of signal tranducer and activator of transcription 5 (STAT5) phosphorylation at the molecular level. Reintroduction of single tyrosine residues revealed the critical role of Y589 and Y591 in reconstituting interleukin-3-independent growth of FLT3-TKD-expressing cells. Combined mutation of Y589 and Y591 to phenylalanine also abrogated ligand-dependent proliferation of FLT3-WT and the transforming potential of FLT3-ITD-with a subsequent abrogation of STAT5 phosphorylation. CONCLUSION: We identified two tyrosine residues, Y589 and Y591, in the juxtamembrane domain that are critical for the ligand-dependent activation of FLT3-WT and the transforming potential of oncogenic FLT3 mutants.


Assuntos
Transformação Celular Neoplásica/química , Peptídeos e Proteínas de Sinalização Intracelular/química , Transdução de Sinais/fisiologia , Tirosina/química , Sequência de Aminoácidos , Animais , Western Blotting , Linhagem Celular , Transformação Celular Neoplásica/genética , Ativação Enzimática/fisiologia , Citometria de Fluxo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Fosforilação , Mutação Puntual , Fator de Transcrição STAT5/metabolismo , Relação Estrutura-Atividade , Tirosina/genética
4.
Blood ; 110(2): 686-94, 2007 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-17387224

RESUMO

FLT3-internal tandem duplications (FLT3-ITDs) comprise a heterogeneous group of mutations in patients with acute leukemias that are prognostically important. To characterize the mechanism of transformation by FLT3-ITDs, we sequenced the juxtamembrane region (JM) of FLT3 from 284 patients with acute leukemias. The length of FLT3-ITDs varied from 2 to 42 amino acids (AAs) with a median of 17 AAs. The analysis of duplicated AAs showed that in the majority of patients, the duplications localize between AAs 591 to 599 (YVDFREYEY). Arginine 595 (R595) within this region is duplicated in 77% of patients. Single duplication of R595 in FLT3 conferred factor-independent growth to Ba/F3 cells and activated STAT5. Moreover, deletion or substitution of the duplicated R595 in 2 FLT3-ITD constructs as well as the deletion of wild-type R595 in FLT3-ITD substantially reduced the transforming potential and STAT5 activation, pointing to a critical role of the positive charge of R595 in stabilizing the active confirmation of FLT3-ITDs. Deletion of R595 in FLT3-WT nearly abrogated the ligand-dependent activation of FLT3-WT. Our data provide important insights into the molecular mechanism of transformation by FLT3-ITDs and show that duplication of R595 is important for the leukemic potential of FLT3-ITDs.


Assuntos
Arginina , Leucemia/genética , Tirosina Quinase 3 Semelhante a fms/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Substituição de Aminoácidos , Transformação Celular Neoplásica/genética , Feminino , Duplicação Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Mutagênese , Deleção de Sequência
5.
Blood ; 105(9): 3679-85, 2005 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-15626738

RESUMO

FLT3 (fms-like tyrosine kinase 3) is constitutively activated in about 30% of patients with acute myeloid leukemia (AML) and represents a disease-specific molecular marker. Although FLT3-LM (length mutation) and TKD (tyrosine kinase domain) mutations have been considered to be mutually exclusive, 1% to 2% of patients carry both mutations. However, the functional and clinical significance of this observation is unclear. We demonstrate that FLT3-ITD-TKD dual mutants induce drug resistance toward PTK inhibitors and cytotoxic agents in in vitro model systems. As molecular mechanisms of resistance, we found that FLT3-ITD-TKD mutants cause hyperactivation of STAT5 (signal transducer and activator of transcription-5), leading to upregulation of Bcl-x(L) and RAD51 and arrest in the G(2)M phase of the cell cycle. Overexpression of Bcl-x(L) was identified as the critical mediator of drug resistance and recapitulates the PTK inhibitor and daunorubicin-resistant phenotype in FLT3-ITD cells. The combination of rapamycin, a selective mTOR inhibitor, and FLT3 PTK inhibitors restored the drug sensitivity in FLT3 dual mutant-expressing cells. Our data provide the molecular basis for understanding clinical FLT3 PTK inhibitor resistance and point to therapeutical strategies to overcome drug resistance in patients with AML.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Leucemia Mieloide/tratamento farmacológico , Mutação Puntual , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Proteínas Recombinantes de Fusão/farmacologia , Sequências de Repetição em Tandem , Doença Aguda , Animais , Linhagem Celular , Proteínas de Ligação a DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Inibidores Enzimáticos/farmacologia , Humanos , Camundongos , Proteínas do Leite/efeitos dos fármacos , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Rad51 Recombinase , Receptores Proteína Tirosina Quinases/genética , Proteínas Recombinantes de Fusão/genética , Fator de Transcrição STAT5 , Transativadores/efeitos dos fármacos , Transfecção , Regulação para Cima/efeitos dos fármacos , Proteína bcl-X , Tirosina Quinase 3 Semelhante a fms
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