Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Am J Kidney Dis ; 71(5): 627-635, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29396240

RESUMO

BACKGROUND: Although dialysis may not provide a large survival benefit for older patients with kidney failure, few are informed about conservative management. Barriers and facilitators to discussions about conservative management and nephrologists' decisions to present the option of conservative management may vary within the nephrology provider community. STUDY DESIGN: Interview study of nephrologists. SETTING & PARTICIPANTS: National sample of US nephrologists sampled based on sex, years in practice, practice type, and region. METHODOLOGY: Qualitative semistructured interviews continued until thematic saturation. ANALYTICAL APPROACH: Thematic and narrative analysis of recorded and transcribed interviews. RESULTS: Among 35 semistructured interviews with nephrologists from 18 practices, 37% described routinely discussing conservative management ("early adopters"). 5 themes and related subthemes reflected issues that influence nephrologists' decisions to discuss conservative management and their approaches to these discussions: struggling to define nephrologists' roles (determining treatment, instilling hope, and improving patient symptoms), circumventing end-of-life conversations (contending with prognostic uncertainty, fearing emotional backlash, jeopardizing relationships, and tailoring information), confronting institutional barriers (time constraints, care coordination, incentives for dialysis, and discomfort with varied conservative management approaches), conservative management as "no care," and moral distress. Nephrologists' approaches to conservative management discussions were shaped by perceptions of their roles and by a common view of conservative management as no care. Their willingness to pursue conservative management was influenced by provider- and institutional-level barriers and experiences with older patients who regretted or had been harmed by dialysis (moral distress). Early adopters routinely discussed conservative management as a way of relieving moral distress, whereas others who were more selective in discussing conservative management experienced greater distress. LIMITATIONS: Participants' views are likely most transferable to large academic medical centers, due to oversampling of academic clinicians. CONCLUSIONS: Our findings clarify how moral distress serves as a catalyst for conservative management discussion and highlight points of intervention and mechanisms potentially underlying low conservative management use in the United States.


Assuntos
Tomada de Decisão Clínica , Tratamento Conservador/métodos , Nefrologistas , Segurança do Paciente/estatística & dados numéricos , Insuficiência Renal Crônica/terapia , Idoso , Atitude do Pessoal de Saúde , Feminino , Avaliação Geriátrica , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Relações Médico-Paciente , Prognóstico , Pesquisa Qualitativa , Qualidade de Vida , Diálise Renal/métodos , Diálise Renal/psicologia , Insuficiência Renal Crônica/diagnóstico , Estados Unidos
2.
J Biol Chem ; 285(8): 5664-73, 2010 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-20007713

RESUMO

E3 ubiquitin ligases catalyze the final step of ubiquitin conjugation and regulate numerous cellular processes. The HECT class of E3 ubiquitin (Ub) ligases directly transfers Ub from bound E2 enzyme to a myriad of substrates. The catalytic domain of HECT Ub ligases has a bilobal architecture that separates the E2 binding region and catalytic site. An important question regarding HECT domain function is the control of ligase activity and specificity. Here we present a functional analysis of the HECT domain of the E3 ligase HUWE1 based on crystal structures and show that a single N-terminal helix significantly stabilizes the HECT domain. We observe that this element modulates HECT domain activity, as measured by self-ubiquitination induced in the absence of this helix, as distinct from its effects on Ub conjugation of substrate Mcl-1. Such subtle changes to the protein may be at the heart of the vast spectrum of substrate specificities displayed by HECT domain E3 ligases.


Assuntos
Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina/metabolismo , Ubiquitinação/fisiologia , Domínio Catalítico/fisiologia , Cristalografia por Raios X , Humanos , Proteína de Sequência 1 de Leucemia de Células Mieloides , Estrutura Secundária de Proteína/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/química , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Especificidade por Substrato/fisiologia , Proteínas Supressoras de Tumor , Ubiquitina/química , Ubiquitina/genética , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/genética
3.
Kidney Med ; 2(2): 116-124, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32734232

RESUMO

RATIONALE & OBJECTIVE: Older patients with advanced chronic kidney disease (CKD) use intensive care at the end of life and die in a hospital more frequently than patients with cancer or heart disease. Advance care planning (ACP) can help align treatment with patient preferences and improve patient-centered care, yet ACP quality and experiences among older patients with CKD and their care partners remain incompletely understood, particularly among the non-dialysis-dependent population. STUDY DESIGN: In-person interviewer-administered surveys of patients 70 years and older with non-dialysis-dependent CKD stage 4 or 5 and their self-identified care partners. SETTING & PARTICIPANTS: 42 participants (31 patients, 11 care partners) at 2 clinical sites in greater Boston. OUTCOMES: Completion of advance directives and self-reported perceptions, preferences, and experiences of ACP. ANALYTICAL APPROACH: Descriptive analysis of patient and care partner surveys. McNemar test analysis to compare patient and care partner responses. RESULTS: Most patients had written advance directives (64%) and surrogate decision makers (81%). Although patients reported positive perceptions and high trust in their clinicians' judgment, few (16%) had actually discussed preferences for life-sustaining treatment with their nephrologists. Few ACP discussions included components reflective of high-quality ACP: 16% of patients had been asked about their values concerning end-of-life care and 7% had discussed issues of decision-making capacity and consent to care should their health decline. When presented with 2 hypothetical scenarios (stroke/heart attack or dementia), nearly all patients and care partners reported a preference for comfort care over delaying death. Care partners were more likely than patients to report that they had experienced discussion components reflective of high-quality ACP with the clinical team. LIMITATIONS: Single metropolitan area; most patients did not identify a care partner; nonresponse bias and small sample size. CONCLUSIONS: Patients often believed that their clinicians understood their end-of-life wishes despite not having engaged in ACP conversations that would make those wishes known. Improving clinical ACP communication may result in end-of-life treatment that better aligns with patient goals.

4.
Clin J Am Soc Nephrol ; 13(8): 1188-1196, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-30049850

RESUMO

BACKGROUND AND OBJECTIVES: Despite guidelines recommending shared decision making, nephrologists vary significantly in their approaches to discussing conservative management for kidney replacement therapy with older patients. Many older patients do not perceive dialysis initiation as a choice or receive sufficient information about conservative management for reasons incompletely understood. We examined how nephrologists' perceptions of key outcomes and successful versus failed treatment discussions shape their approach and characterized different models of decision making, patient engagement, and conservative management discussion. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Our qualitative study used semistructured interviews with a sample of purposively sampled nephrologists. Interviews were conducted from June 2016 to May 2017 and continued until thematic saturation. Data were analyzed using typological and thematic analyses. RESULTS: Among 35 nephrologists from 18 practices, 20% were women, 66% had at least 10 years of nephrology experience, and 80% were from academic medical centers. Four distinct approaches to decision making emerged: paternalist, informative (patient led), interpretive (navigator), and institutionalist. Five themes characterized differences between these approaches, including patient autonomy, engagement and deliberation (disclosing all options, presenting options neutrally, eliciting patient values, and offering explicit treatment recommendation), influence of institutional norms, importance of clinical outcomes (e.g., survival and dialysis initiation), and physician role (educating patients, making decisions, pursuing active therapies, and managing symptoms). Paternalists and institutionalists viewed initiation of dialysis as a measure of success, whereas interpretive and informative nephrologists focused on patient engagement, quality of life, and aligning patient values with treatment. In this sample, only one third of providers presented conservative management to patients, all of whom followed either informative or interpretive approaches. The interpretive model best achieved shared decision making. CONCLUSIONS: Differences in nephrologists' perceptions of their role, patient autonomy, and successful versus unsuccessful encounters contribute to variation in decision making for patients with kidney disease.


Assuntos
Atitude do Pessoal de Saúde , Tomada de Decisões , Falência Renal Crônica/terapia , Nefrologia , Participação do Paciente , Diálise Renal , Fatores Etários , Idoso , Tratamento Conservador , Feminino , Humanos , Masculino , Pesquisa Qualitativa
5.
ACS Chem Biol ; 4(4): 275-87, 2009 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-19256548

RESUMO

Protein modification by ubiquitin (Ub) and ubiquitin-like modifiers (Ubl) requires the action of activating (E1), conjugating (E2), and ligating (E3) enzymes and is a key step in the specific destruction of proteins. Deubiquitinating enzymes (DUBs) deconjugate substrates modified with Ub/Ubl's and recycle Ub inside the cell. Genome mining based on sequence homology to proteins with known function has assigned many enzymes to this pathway without confirmation of either conjugating or DUB activity. Function-dependent methodologies are still the most useful for rapid identification or assessment of biological activity of expressed proteins from cells. Activity-based protein profiling uses chemical probes that are active-site-directed for the classification of protein activities in complex mixtures. Here we show that the design and use of an expanded set of Ub-based electrophilic probes allowed us to recover and identify members of each enzyme class in the ubiquitin-proteasome system, including E3 ligases and DUBs with previously unverified activity. We show that epitope-tagged Ub-electrophilic probes can be used as activity-based probes for E3 ligase identification by in vitro labeling and activity studies of purified enzymes identified from complex mixtures in cell lysate. Furthermore, the reactivity of our probe with the HECT domain of the E3 Ub ligase ARF-BP1 suggests that multiple cysteines may be in the vicinity of the E2-binding site and are capable of the transfer of Ub to self or to a substrate protein.


Assuntos
Sondas Moleculares/metabolismo , Complexos Ubiquitina-Proteína Ligase/metabolismo , Ubiquitina/metabolismo , Sequência de Aminoácidos , Animais , Camundongos , Sondas Moleculares/síntese química , Sondas Moleculares/química , Dados de Sequência Molecular , Estrutura Molecular , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Alinhamento de Sequência , Ubiquitina/química , Complexos Ubiquitina-Proteína Ligase/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA