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1.
JAMA Netw Open ; 7(4): e246228, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38607626

RESUMO

Importance: Less than 5% of patients with cancer enroll in a clinical trial, partly due to financial and logistic burdens, especially among underserved populations. The COVID-19 pandemic marked a substantial shift in the adoption of decentralized trial operations by pharmaceutical companies. Objective: To assess the current global state of adoption of decentralized trial technologies, understand factors that may be driving or preventing adoption, and highlight aspirations and direction for industry to enable more patient-centric trials. Design, Setting, and Participants: The Bloomberg New Economy International Cancer Coalition, composed of patient advocacy, industry, government regulator, and academic medical center representatives, developed a survey directed to global biopharmaceutical companies of the coalition from October 1 through December 31, 2022, with a focus on registrational clinical trials. The data for this survey study were analyzed between January 1 and 31, 2023. Exposure: Adoption of decentralized clinical trial technologies. Main Outcomes and Measures: The survey measured (1) outcomes of different remote monitoring and data collection technologies on patient centricity, (2) adoption of these technologies in oncology and all therapeutic areas, and (3) barriers and facilitators to adoption using descriptive statistics. Results: All 8 invited coalition companies completed the survey, representing 33% of the oncology market by revenues in 2021. Across nearly all technologies, adoption in oncology trials lags that of all trials. In the current state, electronic diaries and electronic clinical outcome assessments are the most used technology, with a mean (SD) of 56% (19%) and 51% (29%) adoption for all trials and oncology trials, respectively, whereas visits within local physician networks is the least adopted at a mean (SD) of 12% (18%) and 7% (9%), respectively. Looking forward, the difference between the current and aspired adoption rate in 5 years for oncology is large, with respondents expecting a 40% or greater absolute adoption increase in 8 of the 11 technologies surveyed. Furthermore, digitally enabled recruitment, local imaging capabilities, and local physician networks were identified as technologies that could be most effective for improving patient centricity in the long term. Conclusions and Relevance: These findings may help to galvanize momentum toward greater adoption of enabling technologies to support a new paradigm of trials that are more accessible, less burdensome, and more inclusive.


Assuntos
Ensaios Clínicos como Assunto , Neoplasias , Humanos , Coleta de Dados , Oncologia
2.
Lancet Oncol ; 19(3): 310-322, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29449192

RESUMO

BACKGROUND: Obesity has been linked to increased mortality in several cancer types; however, the relation between obesity and survival outcomes in metastatic melanoma is unknown. The aim of this study was to examine the association between body-mass index (BMI) and progression-free survival or overall survival in patients with metastatic melanoma who received targeted therapy, immunotherapy, or chemotherapy. METHODS: This retrospective study analysed independent cohorts of patients with metastatic melanoma assigned to treatment with targeted therapy, immunotherapy, or chemotherapy in randomised clinical trials and one retrospective study of patients treated with immunotherapy. Patients were classified according to BMI, following the WHO definitions, as underweight, normal, overweight, or obese. Patients without BMI and underweight patients were excluded. The primary outcomes were the associations between BMI and progression-free survival or overall survival, stratified by treatment type and sex. We did multivariable analyses in the independent cohorts, and combined adjusted hazard ratios in a mixed-effects meta-analysis to provide a precise estimate of the association between BMI and survival outcomes; heterogeneity was assessed with meta-regression analyses. Analyses were done on the predefined intention-to-treat population in the randomised controlled trials and on all patients included in the retrospective study. FINDINGS: The six cohorts consisted of a total of 2046 patients with metastatic melanoma treated with targeted therapy, immunotherapy, or chemotherapy between Aug 8, 2006, and Jan 15, 2016. 1918 patients were included in the analysis. Two cohorts containing patients from randomised controlled trials treated with targeted therapy (dabrafenib plus trametinib [n=599] and vemurafenib plus cobimetinib [n=240]), two cohorts containing patients treated with immunotherapy (one randomised controlled trial of ipilimumab plus dacarbazine [n=207] and a retrospective cohort treated with pembrolizumab, nivolumab, or atezolizumab [n=331]), and two cohorts containing patients treated with chemotherapy (two randomised controlled trials of dacarbazine [n=320 and n=221]) were classified according to BMI as normal (694 [36%] patients), overweight (711 [37%]), or obese (513 [27%]). In the pooled analysis, obesity, compared with normal BMI, was associated with improved survival in patients with metastatic melanoma (average adjusted hazard ratio [HR] 0·77 [95% CI 0·66-0·90] for progression-free survival and 0·74 [0·58-0·95] for overall survival). The survival benefit associated with obesity was restricted to patients treated with targeted therapy (HR 0·72 [0·57-0·91] for progression-free survival and 0·60 [0·45-0·79] for overall survival) and immunotherapy (HR 0·75 [0·56-1·00] and 0·64 [0·47-0·86]). No associations were observed with chemotherapy (HR 0·87 [0·65-1·17, pinteraction=0·61] for progression-free survival and 1·03 [0·80-1·34, pinteraction=0·01] for overall survival). The association of BMI with overall survival for patients treated with targeted and immune therapies differed by sex, with inverse associations in men (HR 0·53 [0·40-0·70]), but no associations observed in women (HR 0·85 [0·61-1·18, pinteraction=0·03]). INTERPRETATION: Our results suggest that in patients with metastatic melanoma, obesity is associated with improved progression-free survival and overall survival compared with those outcomes in patients with normal BMI, and that this association is mainly seen in male patients treated with targeted or immune therapy. These results have implications for the design of future clinical trials for patients with metastatic melanoma and the magnitude of the benefit found supports further investigation of the underlying mechanism of these associations. FUNDING: ASCO/CCF Young Investigator Award, ASCO/CCF Career Development Award, MD Anderson Cancer Center (MDACC) Melanoma Moonshot Program, MDACC Melanoma SPORE, and the Dr Miriam and Sheldon G Adelson Medical Research Foundation.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Índice de Massa Corporal , Melanoma/tratamento farmacológico , Terapia de Alvo Molecular , Obesidade/epidemiologia , Neoplasias Cutâneas/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Imunológicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Feminino , Humanos , Masculino , Melanoma/imunologia , Melanoma/mortalidade , Melanoma/secundário , Pessoa de Meia-Idade , Terapia de Alvo Molecular/efeitos adversos , Terapia de Alvo Molecular/mortalidade , Obesidade/diagnóstico , Obesidade/mortalidade , Intervalo Livre de Progressão , Fatores de Proteção , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologia , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
3.
Eur J Cancer ; 82: 45-55, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28648698

RESUMO

AIM: Understanding predictors of long-term benefit with currently available melanoma therapies is the key for optimising individualised treatments. A prior pooled analysis of dabrafenib plus trametinib (D + T)-randomised trials (median follow-up, 20.0 months) identified baseline lactate dehydrogenase (LDH) and number of organ sites with metastasis as predictive factors for progression-free (PFS) and overall (OS) survival. However, longer-term follow-up analyses are needed to confirm which patients treated with D + T can achieve maximum benefit. METHODS: Three-year landmark data were retrospectively pooled for D + T patients in phase 3 trials (COMBI-d [NCT01584648]; COMBI-v [NCT01597908]). Univariate and multivariate analyses assessed prognostic values of predefined baseline factors; regression tree analysis determined hierarchy and interactions between variables. RESULTS: Long-term pooled outcomes were consistent with individual trial results (N = 563; 3-year PFS, 23%; 3-year OS, 44%). Baseline LDH level and number of organ sites remained strongly associated with and/or predictive of PFS and OS. In addition, baseline sum of lesion diameters (SLD) was identified as a predictor for progression. In the most favourable prognostic group (normal LDH, SLD <66 mm, <3 organ sites; n = 183/563 [33%]), 3-year PFS was 42%. Baseline number of organ sites was also predictive of outcomes in patients with PFS ≥ 6 months. CONCLUSION: Using the largest phase 3 data set available for BRAF/MEK inhibitor combination therapy in melanoma, these results demonstrate that durable responses lasting ≥3 years are possible in subsets of patients with BRAF-mutant melanoma receiving D + T. Although the best predictive model evolved with longer follow-up, factors predicting clinical outcomes with the combination remained consistent with previous analyses.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Melanoma/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Adulto , Idoso , Feminino , Humanos , Imidazóis/administração & dosagem , L-Lactato Desidrogenase/metabolismo , Masculino , Melanoma/metabolismo , Melanoma/patologia , Pessoa de Meia-Idade , Metástase Neoplásica/patologia , Oximas/administração & dosagem , Valor Preditivo dos Testes , Prognóstico , Piridonas/administração & dosagem , Pirimidinonas/administração & dosagem , Fatores de Risco , Análise de Sobrevida
4.
Clin Cancer Res ; 22(3): 567-74, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26446943

RESUMO

PURPOSE: Tumor-derived circulating cell-free DNA (cfDNA) is a potential alternative source from which to derive tumor mutation status. cfDNA data from four clinical studies of the BRAF inhibitor (BRAFi) dabrafenib or the MEK inhibitor (MEKi) trametinib were analyzed to determine the association between BRAF mutation status in cfDNA and tumor tissue, and the association of BRAF cfDNA mutation status with baseline factors and clinical outcome. EXPERIMENTAL DESIGN: Patients with BRAF V600 mutation-positive melanoma were enrolled in each study after central confirmation of BRAF status in tumor using a PCR-based assay. BRAF mutation status in cfDNA from patient plasma collected at baseline, 732 of 836 (88%) enrolled patients in total, was determined. RESULTS: BRAF mutations were detectable in cfDNA in 76% and 81% of patients with BRAF V600E/V600K-positive tumors, respectively. Patients negative for BRAF mutations in cfDNA had longer progression-free survival (PFS) and overall survival in each of the four studies, compared with patients with detectable cfDNA BRAF mutations. The presence of BRAF-mutant cfDNA was an independent prognostic factor for PFS after multivariate adjustment for baseline factors in three of four studies. Patients negative for BRAF mutation-positive cfDNA in plasma had higher response rates to dabrafenib and trametinib. CONCLUSIONS: BRAF mutations in cfDNA are detectable in >75% of late-stage melanoma patients with BRAF mutation-positive tumors. The lack of circulating, BRAF mutation-positive cfDNA is clinically significant for metastatic melanoma patients, and may be a prognostic marker for better disease outcome.


Assuntos
DNA de Neoplasias , Mutação , Neoplasias/genética , Neoplasias/mortalidade , Proteínas Proto-Oncogênicas B-raf/genética , Substituição de Aminoácidos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ensaios Clínicos como Assunto , Códon , DNA de Neoplasias/sangue , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Terapia de Alvo Molecular , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Prognóstico , Inibidores de Proteínas Quinases/administração & dosagem , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Resultado do Tratamento
5.
Lancet Oncol ; 16(13): 1389-98, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26433819

RESUMO

BACKGROUND: In the COMBI-v trial, patients with previously untreated BRAF Val600Glu or Val600Lys mutant unresectable or metastatic melanoma who were treated with the combination of dabrafenib and trametinib had significantly longer overall and progression-free survival than those treated with vemurafenib alone. Here, we present the effects of treatments on health-related quality of life (HRQoL), an exploratory endpoint in the COMBI-v study. METHODS: COMBI-v was an open-label, randomised phase 3 study in which 704 patients with metastatic melanoma with a BRAF Val600 mutation were randomly assigned (1:1) by an interactive voice response system to receive either a combination of dabrafenib (150 mg twice-daily) and trametinib (2 mg once-daily) or vemurafenib monotherapy (960 mg twice-daily) orally as first-line therapy. The primary endpoint was overall survival. In this pre-specified exploratory analysis, we prospectively assessed HRQoL in the intention-to-treat population with the European Organisation for Research and Treatment of Cancer quality of life (EORTC QLQ-C30), EuroQoL-5D (EQ-5D), and Melanoma Subscale of the Functional Assessment of Cancer Therapy-Melanoma (FACT-M), completed at baseline, during study treatment, at disease progression, and after progression. We used a mixed-model, repeated measures ANCOVA to assess differences in mean scores between groups with baseline score as covariate; all p-values are descriptive. The COMBI-v trial is registered with ClinicalTrials.gov, number NCT01597908, and is ongoing for the primary endpoint, but is not recruiting patients. FINDINGS: From June 4, 2012, to Oct 7, 2013, 1645 patients at 193 centres worldwide were screened for eligibility, and 704 patients were randomly assigned to dabrafenib plus trametinib (n=352) or vemurafenib (n=352). Questionnaire completion rates for both groups were high (>95% at baseline, >80% at follow-up assessments, and >70% at disease progression) with similar HRQoL and symptom scores reported at baseline in both treatment groups for all questionnaires. Differences in mean scores between treatment groups were significant and clinically meaningful in favour of the combination compared with vemurafenib monotherapy for most domains across all three questionnaires during study treatment and at disease progression, including EORTC QLQ-C30 global health (7·92, 7·62, 6·86, 7·47, 5·16, 7·56, and 7·57 at weeks 8, 16, 24, 32, 40, 48, and disease progression, respectively; p<0·001 for all assessments except p=0·005 at week 40), EORTC QLQ-C30 pain (-13·20, -8·05, -8·82, -12·69, -12·46, -11·41, and -10·57 at weeks 8, 16, 24, 32, 40, 48, and disease progression, respectively; all p<0·001), EQ-5D thermometer scores (7·96, 8·05, 6·83, 11·53, 7·41, 9·08, and 10·51 at weeks 8, 16, 24, 32, 40, 48, and disease progression, respectively; p<0·001 for all assessments except p=0·006 at week 32), and FACT-M Melanoma Subscale score (3·62, 2·93, 2·45, 3·39, 2·85, 3·00, and 3·68 at weeks 8, 16, 24, 32, 40, 48, and disease progression, respectively; all p<0·001). INTERPRETATION: From the patient's perspective, which integrates not only survival advantage but also disease-associated and adverse-event-associated symptoms, treatment with the combination of a BRAF inhibitor plus a MEK inhibitor (dabrafenib plus trametinib) adds a clear benefit over monotherapy with the BRAF inhibitor vemurafenib and supports the combination therapy as standard of care in this population.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/genética , Imidazóis/uso terapêutico , Indóis/uso terapêutico , Melanoma/tratamento farmacológico , Mutação , Oximas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/genética , Piridonas/uso terapêutico , Pirimidinonas/uso terapêutico , Qualidade de Vida , Neoplasias Cutâneas/tratamento farmacológico , Sulfonamidas/uso terapêutico , Administração Oral , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Análise Mutacional de DNA , Progressão da Doença , Intervalo Livre de Doença , Esquema de Medicação , Predisposição Genética para Doença , Humanos , Imidazóis/administração & dosagem , Imidazóis/efeitos adversos , Indóis/administração & dosagem , Indóis/efeitos adversos , Análise de Intenção de Tratamento , MAP Quinase Quinase Quinases/antagonistas & inibidores , MAP Quinase Quinase Quinases/metabolismo , Melanoma/genética , Melanoma/mortalidade , Melanoma/secundário , Oximas/administração & dosagem , Oximas/efeitos adversos , Fenótipo , Estudos Prospectivos , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Piridonas/administração & dosagem , Piridonas/efeitos adversos , Pirimidinonas/administração & dosagem , Pirimidinonas/efeitos adversos , Fatores de Risco , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologia , Sulfonamidas/administração & dosagem , Sulfonamidas/efeitos adversos , Inquéritos e Questionários , Fatores de Tempo , Resultado do Tratamento , Vemurafenib
6.
Lancet ; 386(9992): 444-51, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26037941

RESUMO

BACKGROUND: Previously, a study of ours showed that the combination of dabrafenib and trametinib improves progression-free survival compared with dabrafenib and placebo in patients with BRAF Val600Lys/Glu mutation-positive metastatic melanoma. The study was continued to assess the secondary endpoint of overall survival, which we report in this Article. METHODS: We did this double-blind phase 3 study at 113 sites in 14 countries. We enrolled previously untreated patients with BRAF Val600Glu or Val600Lys mutation-positive unresectable stage IIIC or stage IV melanoma. Participants were computer-randomised (1:1) to receive a combination of dabrafenib (150 mg orally twice daily) and trametinib (2 mg orally once daily), or dabrafenib and placebo. The primary endpoint was progression-free survival and overall survival was a secondary endpoint. This study is registered with ClinicalTrials.gov, number NCT01584648. FINDINGS: Between May 4, 2012, and Nov 30, 2012, we screened 947 patients for eligibility, of whom 423 were randomly assigned to receive dabrafenib and trametinib (n=211) or dabrafenib only (n=212). The final data cutoff was Jan 12, 2015, at which time 222 patients had died. Median overall survival was 25·1 months (95% CI 19·2-not reached) in the dabrafenib and trametinib group versus 18·7 months (15·2-23·7) in the dabrafenib only group (hazard ratio [HR] 0·71, 95% CI 0·55-0·92; p=0·0107). Overall survival was 74% at 1 year and 51% at 2 years in the dabrafenib and trametinib group versus 68% and 42%, respectively, in the dabrafenib only group. Based on 301 events, median progression-free survival was 11·0 months (95% CI 8·0-13·9) in the dabrafenib and trametinib group and 8·8 months (5·9-9·3) in the dabrafenib only group (HR 0·67, 95% CI 0·53-0·84; p=0·0004; unadjusted for multiple testing). Treatment-related adverse events occurred in 181 (87%) of 209 patients in the dabrafenib and trametinib group and 189 (90%) of 211 patients in the dabrafenib only group; the most common was pyrexia (108 patients, 52%) in the dabrafenib and trametinib group, and hyperkeratosis (70 patients, 33%) in the dabrafenib only group. Grade 3 or 4 adverse events occurred in 67 (32%) patients in the dabrafenib and trametinib group and 66 (31%) patients in the dabrafenib only group. INTERPRETATION: The improvement in overall survival establishes the combination of dabrafenib and trametinib as the standard targeted treatment for BRAF Val600 mutation-positive melanoma. Studies assessing dabrafenib and trametinib in combination with immunotherapies are ongoing. FUNDING: GlaxoSmithKline.


Assuntos
Imidazóis/administração & dosagem , Melanoma/tratamento farmacológico , Oximas/administração & dosagem , Piridonas/administração & dosagem , Pirimidinonas/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas B-raf/genética , Resultado do Tratamento , Adulto Jovem
7.
Exp Neurol ; 212(1): 53-62, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18462720

RESUMO

Mismatches between tissue perfusion-weighted imaging (PWI; an index of blood flow deficit) and cellular diffusion-weighted imaging (DWI; an index of tissue injury) provide information on potentially salvageable penumbra tissue in focal stroke and can identify "treatable" stroke patients. The present pre-clinical studies were conducted to: a.) Determine PWI (using perfusion delay) and DWI measurements in two experimental stroke models, b.) Utilize these measurements to characterize selective ET(A) receptor antagonism (i.e., determine efficacy, time-to-treatment and susceptibility to treatment in the different stroke models), and c.) Determine if increasing the reduced blood flow following a stroke is a mechanism of protection. Permanent middle cerebral artery occlusion (MCAO) or sham surgeries were produced in Sprague Dawley rats (SD; proximal MCAO; hypothesized to be a model of slowly evolving brain injury with a significant penumbra) and in spontaneously hypertensive rats (SHR; distal MCAO; hypothesized to be a model of rapidly evolving brain injury with little penumbra). Infusions of vehicle or SB 234551 (3, 10, or 30 microg/kg/min) were initiated at 0, 75, and/or 180 min post-surgery and maintained for the remainder of 24 h post-surgery. Hyper-intense areas of perfusion delay (PWI) in the forebrain were measured using Gadolinium (Gd) bolus contrast. DWI hyper-intense areas were also measured, and the degree of forebrain DWI-PWI mismatch was determined. Region specific analyses (ROI) were also conducted in the core ischemic and low perfusion/penumbra areas to provide indices of perfusion and changes in the degree of tissue perfusion due to SB 234551 treatment. At 24 h post-surgery, final infarct volume was measured by DWI and by staining forebrain slices. Following SD proximal MCAO, there was a significant mismatch in the ischemic forebrain PWI compared to DWI (PWI>DWI) at 60 min which was maintained up to 150 min (all p<0.05). By 24 h post-stroke, infarct volume was identical to the area of early perfusion deficit/PWI, suggesting a slow progression of infarct development that expanded into the significant, earlier cortical penumbra (i.e., model with salvageable tissue with potential for intervention). When SB 234551 was administered within the period of peak mismatch (i.e., at 75 min post-stroke), SB 234551 provided significant dose-related reductions in cortical (penumbral) progression to infarction (p<0.05). Cortical protection was related to an increased/normalization of the stroke-induced decrease in tissue perfusion in cortical penumbra areas (p<0.05). No SB 234551-induced changes in reduced tissue perfusion were observed in the striatum core ischemic area. Also, when SB-234551 was administered beyond the time of mismatch, no effect on cortical penumbra progression to infarct was observed. In comparison and strikingly different, following SHR distal MCAO there was no mismatch between PWI and DWI (PWI=DWI) as early as 60 min post-stroke, with this early change in SHR DWI being identical to the final infarct volume at 24 h, suggesting a rapidly occurring brain injury with little cortical penumbra (i.e., model with little salvageable tissue or potential for intervention). In distal MCAO, SB 234551 administered immediately at the time of stroke did not have any effect on infarct volume in SHR. These data demonstrate that selective blockade of ET(A) receptors is protective following proximal MCAO in SD (i.e. a model similar to "treatable" clinical patients). The protective mechanism appears to be due to enhanced collateral blood flow and salvage of penumbra. Therefore, the use of PWI-DWI mismatch signatures can identify treatable stroke models characterized by a salvageable penumbra and can define appropriate time to treatment protocols. In addition, tissue perfusion information obtained under these conditions might clarify mechanism of protection in the evaluation of protective compounds for focal stroke.


Assuntos
Infarto Encefálico/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Imagem de Difusão por Ressonância Magnética/métodos , Dioxóis/farmacologia , Antagonistas do Receptor de Endotelina A , Pirazóis/farmacologia , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Encéfalo/patologia , Encéfalo/fisiopatologia , Infarto Encefálico/patologia , Infarto Encefálico/fisiopatologia , Artérias Cerebrais/efeitos dos fármacos , Artérias Cerebrais/metabolismo , Artérias Cerebrais/fisiopatologia , Circulação Cerebrovascular/efeitos dos fármacos , Circulação Cerebrovascular/fisiologia , Dioxóis/uso terapêutico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Serviços Médicos de Emergência/normas , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Pirazóis/uso terapêutico , Ratos , Ratos Endogâmicos SHR , Ratos Sprague-Dawley , Receptor de Endotelina A/metabolismo , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/fisiopatologia , Fatores de Tempo , Resultado do Tratamento
8.
Proc Natl Acad Sci U S A ; 100(2): 715-20, 2003 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-12522260

RESUMO

Sublethal insults can induce tolerance to subsequent stressors in neurons. As cell death activators such as ROS generation and decreased ATP can initiate tolerance, we tested whether other cellular elements normally associated with neuronal injury could add to this process. In an in vivo model of ischemic tolerance, we were surprised to observe widespread caspase 3 cleavage, without cell death, in preconditioned tissue. To dissect the preconditioning pathways activating caspases, and the mechanisms by which these proteases are held in check, we developed an in vitro model of excitotoxic tolerance. In this model, antioxidants and caspase inhibitors blocked ischemia-induced protection against N-methyl-d-aspartate toxicity. Moreover, agents that blocked preconditioning also attenuated induction of HSP 70; transient overexpression of a constitutive form of this protein prevented HSP 70 up-regulation and blocked tolerance. We outline a neuroprotective pathway where events normally associated with apoptotic cell death are critical for cell survival.


Assuntos
Caspases/fisiologia , Precondicionamento Isquêmico , Neurônios/patologia , Animais , Caspase 3 , Células Cultivadas , Ativação Enzimática , Proteínas de Choque Térmico HSP70/biossíntese , N-Metilaspartato/farmacologia , Canais de Potássio/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Ratos , Espécies Reativas de Oxigênio , Fatores de Tempo , Proteína bcl-X
9.
Expert Opin Investig Drugs ; 11(4): 469-82, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11922856

RESUMO

Spinal cord injury remains a devastating neurological condition with limited therapeutic opportunities. Since decompressive surgery and high-dose methylprednisolone have limited utility for most patients, spinal cord injury clearly represents a major medical challenge. Experimental evidence has suggested that secondary cellular injury processes may be a realistic target for therapeutic intervention with the goal of inhibiting the progression of detrimental changes that normally follows traumatic injury to the cord. Preventing or reducing this delayed cellular injury may alone improve neurological recovery or facilitate future regenerative approaches to the injured cord. This review summarises recent advances in the development of pharmacological agents targeting the acute phase of spinal cord injury as well as potential strategies to facilitate regeneration of the spinal cord.


Assuntos
Fármacos Neuroprotetores/uso terapêutico , Traumatismos da Medula Espinal/tratamento farmacológico , Ensaios Clínicos como Assunto , Terapia Genética , Transplante de Células-Tronco Hematopoéticas , Humanos , Canais Iônicos/efeitos dos fármacos , Canais Iônicos/fisiologia , Metilprednisolona/uso terapêutico , Regeneração Nervosa/efeitos dos fármacos , Regeneração Nervosa/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/cirurgia
10.
J Neurosci Methods ; 113(2): 159-66, 2002 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-11772437

RESUMO

BACKGROUND: Recent studies have demonstrated spontaneous and prolonged hyperthermia following stroke in both humans and rodents. However, a full characterization of these pyretic changes and the effects of anti-pyretic drugs on outcome is not available. METHODS: The aims of this study were to monitor conscious body temperature (n=10 per group) using programmable microchips for up to 24 h in rats following either permanent (p) or 90 min transient (t) middle cerebral artery occlusion (MCAO) or sham surgery, and to evaluate the relationship to hypothalamic damage. Also, the effects of anti-pyretic drug therapy on body temperature and infarct volume were evaluated in animals treated with vehicle, optimal doses of either aspirin or paracetamol (250 mg/kg i.p.) following pMCAO (n=10 per group). RESULTS: At 1 h, body temperature significantly (P<0.01) increased to 38.6+/-0.2 degrees C following tMCAO and 38.9+/-0.1 degrees C following pMCAO compared with sham-operated animals (37.1+/-0.1 degrees C). Sustained hyperthermia (> or =38.1 degrees C) was observed for up to 24 h following pMCAO but approached baseline within 30 min (37.6+/-0.2 degrees C) following tMCAO with reperfusion. The post-stroke pyrexia was related to the degree of ischemia where hypothalamic damage was observed in (80%) of the animals undergoing pMCAO and (0%) in the tMCAO group (P<0.05). Treatment with paracetamol (250 mg/kg i.p.) significantly attenuated (P<0.05) but did not normalize core body temperature up to 2 h (38.2+/-0.4 degrees C) compared with vehicle treated animals (39.3+/-0.1 degrees C). Aspirin had no effect on temperature under these conditions. Hypothalamic damage and lesion volume were not different between animals treated with paracetamol (253.3+/-8.5 mm(3)), aspirin (264.0+/-11.6 mm(3)) or vehicle (274.4+/-8.2 mm(3)). CONCLUSIONS: This study is the first to demonstrate the utility of programmable microchips to monitor serial changes in post-stroke hyperthermia. The sustained post-stroke pyrexia and negative effects of antipyretic treatment may be attributed to the extensive hypothalamic injury suggesting that better pharmacologic approaches to reduce body temperature should be identified and evaluated for brain protection in severe experimental stroke.


Assuntos
Acetaminofen/farmacologia , Analgésicos não Narcóticos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Aspirina/farmacologia , Febre/tratamento farmacológico , Infarto da Artéria Cerebral Média/tratamento farmacológico , Animais , Temperatura Corporal/efeitos dos fármacos , Febre/patologia , Febre/fisiopatologia , Hipotálamo/patologia , Hipotálamo/fisiopatologia , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Ratos , Ratos Sprague-Dawley , Software , Telemetria/instrumentação
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