RESUMO
New therapeutic approaches in Alzheimer's disease are urgently needed. The normal plasma protein, serum amyloid P component (SAP), is always present in cerebrospinal fluid (CSF) and in the pathognomonic lesions of Alzheimer's disease, cerebrovascular and intracerebral Abeta amyloid plaques and neurofibrillary tangles, as a result of its binding to amyloid fibrils and to paired helical filaments, respectively. SAP itself may also be directly neurocytotoxic. Here, in this unique study in Alzheimer's disease of the bis(d-proline) compound, (R)-1-[6-[(R)-2-carboxy-pyrrolidin-1-yl]-6-oxo-hexanoyl]pyrrolidine-2-carboxylic acid (CPHPC), we observed depletion of circulating SAP and also remarkable, almost complete, disappearance of SAP from the CSF. We demonstrate that SAP depletion in vivo is caused by CPHPC cross-linking pairs of SAP molecules in solution to form complexes that are immediately cleared from the plasma. We have also solved the structure of SAP complexed with phosphothreonine, its likely ligand on hyperphosphorylated tau protein. These results support further clinical study of SAP depletion in Alzheimer's disease and potentially other neurodegenerative diseases.
Assuntos
Doença de Alzheimer/metabolismo , Ácidos Carboxílicos/administração & dosagem , Pirrolidinas/administração & dosagem , Componente Amiloide P Sérico/antagonistas & inibidores , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Dicroísmo Circular , Cristalografia por Raios X , Humanos , Espectrometria de Massas , Pessoa de Meia-Idade , Projetos Piloto , Conformação Proteica , Componente Amiloide P Sérico/líquido cefalorraquidiano , Componente Amiloide P Sérico/químicaRESUMO
Patients with advanced dementia often receive poor end-of-life care. We aimed to design and pilot a palliative care and advance care plan (ACP) intervention. Patients had undergone emergency hospital admission and had severe dementia. The intervention consisted of a palliative care patient assessment which informed an ACP discussion with the carer, who was offered the opportunity to write an ACP for the person with dementia. Carer-patient dyads were randomized to 'usual care' or the intervention. Carer-related outcome measures included the Kessler Distress Scale, Decision Satisfaction Inventory, Client Satisfaction Questionnaire and the Euroqol-5D, measured at baseline, six weeks, six months and three months after bereavement. The Satisfaction with End of Life Care in Dementia Scale was completed if the patient died. The 32 patient participants were physically frail and in the advanced stages of dementia: 62% had pressure damage to the skin, all needed feeding assistance and 95% were in pain. Nearly 50% died during the six-month follow-up period. Carers were difficult to recruit during acute admission; 33 patients and carers entered the study (22 intervention arm; 11 control arm). Only seven carers made ACPs. The care planning discussion was well received, but few carers wrote an ACP, despite intensive support from an experienced nurse specialist. Advance care planning is, in theory, a necessary intervention for people with severe dementia; the reluctance of carers to write plans needs to be explored further.
Assuntos
Planejamento Antecipado de Cuidados , Cuidadores , Demência/enfermagem , Cuidados Paliativos , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos de Deglutição/enfermagem , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/enfermagem , Seleção de Pacientes , Projetos Piloto , Qualidade de Vida , Inquéritos e QuestionáriosRESUMO
BACKGROUND: There is increasing interest in improving the quality of care that patients with advanced dementia receive when they are dying. Our understanding of the palliative care needs of these patients and the natural history of advanced disease is limited. Many people with advanced dementia have unplanned emergency admissions to the acute hospital; this is a critical event: half will die within 6 months. These patients have complex needs but often lack capacity to express their wishes. Often carers are expected to make decisions. Advance care planning discussions are rarely performed, despite potential benefits such more consistent supportive healthcare, a reduction in emergency admissions to the acute hospital and better resolution of carer bereavement. DESIGN/METHODS: We have used the MRC complex interventions framework, a "bottom-up" methodology, to develop an intervention for patients with advanced dementia and their carers aiming to 1) define end of life care needs for both patients and carers, 2) pilot a palliative care intervention and 3) produce a framework for advance care planning for patients.The results of qualitative phase 1 work, which involved interviews with carers, hospital and primary care staff from a range of disciplines, have been used to identify key barriers and challenges. For the exploratory trial, 40 patients will be recruited to each of the control and intervention groups. The intervention will be delivered by a nurse specialist. We shall investigate and develop methodology for a phase 3 randomised controlled trial. For example we shall explore the feasibility of randomisation, how best to optimise recruitment, decide on appropriate outcomes and obtain data for power calculations. We will evaluate whether the intervention is pragmatic, feasible and deliverable on acute hospital wards and test model fidelity and its acceptability to carers, patients and staff. DISCUSSION: Results of qualitative phase 1 work suggested that carers and staff were keen to discuss these issues and guided the development of the intervention and choice of outcomes. This will be vital in moving to a phase III trial that is pragmatic and feasible for these complex patients within the NHS. TRIAL REGISTRATION: ISRCTN03330837.
RESUMO
BACKGROUND: The study investigated whether donepezil exerts symptomatic benefit in patients with posterior cortical atrophy (PCA), an atypical variant of Alzheimer's disease. METHODS: A single-centre, double-blind, placebo-controlled, cross-over clinical trial was performed to assess the efficacy of donepezil in patients with PCA. Each patient received either donepezil (5 mg once daily in the first 6 weeks and 10 mg once daily in the second 6 weeks) or placebo for 12 weeks. After a 2-week washout period, each patient received the other treatment arm during the following 12 weeks followed by another 2-week washout period. The primary outcome was the Mini-Mental State Examination (MMSE) at 12 weeks. Secondary outcome measures were five neuropsychological tests reflecting parieto-occipital function. Intention-to-treat analysis was used. For each outcome measure, carry-over effects were first assessed. If present, then analysis was restricted to the first 12-week period. Otherwise, the standard approach to the analysis of a 2 × 2 cross-over trial was used. RESULTS: Eighteen patients (13 females) were recruited (mean age 61.6 years). There was a protocol violation in one patient, who subsequently withdrew from the study due to gastrointestinal side effects. There was statistically significant (p < 0.05) evidence of a carry-over effect on MMSE. Therefore, the analysis of treatment effect on MMSE was restricted to the first 12-week period. Treatment effect at 6 weeks was statistically significant (difference = 2.5 in favour of donepezil, 95% CI 0.1 to 5.0, p < 0.05). Treatment effect at 12 weeks was close, but not statistically significant (difference = 2.0 in favour of donepezil, 95% CI -0.1 to 4.5, p > 0.05). There were no statistically significant treatment effects on any of the five neuropsychological tests, except for digit span at 12 weeks (higher by 0.5 digits in favour of placebo, 95% CI 0.1 to 0.9). Gastrointestinal side effects occurred most frequently, affecting 13/18 subjects (72%), and were the cause of study discontinuation in one subject. Nightmares and vivid dreams occurred in 8/18 subjects (44%), and were statistically more frequent during treatment with donepezil. CONCLUSIONS: In this small study, there was no statistically significant treatment effect of donepezil on the primary outcome measure (MMSE score at 12 weeks) in PCA patients, who appear to be particularly susceptible to the development of nightmares and vivid dreams when treated. TRIAL REGISTRATION: Trial registration: Current Controlled Trials ISRCTN22636071 . Retrospectively registered 19 May 2010.