Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
2.
Blood Transfus ; 12(2): 210-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24333084

RESUMO

BACKGROUND: Receipt of blood transfusions is associated with the major consequences of prematurity such as bronchopulmonary dysplasia. Transfusion-mediated (iron-induced) oxidative damage, coupled with the limited ability of the premature baby to deal with enhanced iron and oxidative load may contribute to this. Adverse effects of transfusion may be related to duration of storage. This study examined the influence of storage on iron and oxidative status in paediatric packed red blood cell units. MATERIALS AND METHODS: Paediatric packed red blood cell units were sampled 3 days post-donation, then at 7 days and weekly until day 35. The extracellular medium was separated and the following measured: total iron concentration, total iron binding capacity, non-transferrin-bound iron, haemoglobin, total and reduced ascorbate, glutathione and malondialdehyde. RESULTS: Measurable total and non-transferrin bound iron were present in the extracellular fluid of paediatric packs on day 3. Both parameters rose almost linearly to maximal values at 35 days. Haemoglobin and malondialdehyde levels rose gradually from day 3 to day 21, then more steeply to day 35. Ascorbate existed mainly in the oxidised form and fell rapidly towards the end of storage. Intracellular GSH fell throughout the period of storage. Strong correlations existed between biomarkers of oxidative damage and iron parameters. DISCUSSION: These data suggest that iron released following the initial preparation of packed red blood cell units may derive from free radical-mediated oxidative damage to the red blood cells and haemoglobin, rather than from extracellular haemoglobin. Iron continues to be released during storage as antioxidant protection declines. A cycle of free radical-mediated damage may initiate and then further exacerbate iron release during storage which, in turn, may mediate further free radical-mediated cellular damage. The potential consequences to recipients of older stored blood may be significant.


Assuntos
Antioxidantes/metabolismo , Preservação de Sangue , Eritrócitos/metabolismo , Ferro/metabolismo , Estresse Oxidativo , Adolescente , Ácido Ascórbico/metabolismo , Criança , Pré-Escolar , Transfusão de Eritrócitos/efeitos adversos , Feminino , Glutationa/metabolismo , Hemoglobinas/metabolismo , Humanos , Masculino , Malondialdeído/metabolismo , Fatores de Tempo
3.
BMC Health Serv Res ; 13: 203, 2013 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-23734903

RESUMO

BACKGROUND: Venous thromboembolism (VTE) is a major cause of morbidity and mortality in hospitalised patients. VTE prevention has been identified as a major health need internationally to improve patient safety. A National Institute for Health and Clinical Excellence (NICE) guideline was issued in February 2010. Its key priorities were to assess patients for risk of VTE on admission to hospital, assess patients for bleeding risk and evaluate the risks and benefits of prescribing VTE prophylaxis. The aim of this study was to evaluate the implementation of NICE guidance and its impact on patient safety. METHODS: A before-after observational design was used to investigate changes in VTE risk assessment documentation and inappropriate prescribing of prophylaxis between the year prior to (2009) and the year following (2010) the implementation of NICE guidance, using data from a 3-week period during each year. A total of 408 patients were sampled in each year across four hospitals in the NHS South region. RESULTS: Implementation strategies such as audit, education and training were used. The percentage of patients for whom a VTE risk assessment was documented increased from 51.5% (210/408) in 2009 to 79.2% (323/408) in 2010; difference 27.7% (95% CI: 21.4% to 33.9%; p < 0.001). There was little evidence of change in the percentage who were prescribed prophylaxis amongst patients without a risk assessment (71.7% (142/198) in 2009 and 68.2% (58/85) in 2010; difference -3.5% (95% CI: -15.2% to 8.2%; p =0.56) nor the percentage who were prescribed low molecular weight heparin amongst patients with a contraindication (14% (4/28) in 2009 and 15% (6/41) in 2010; RD = 0.3% (95% CI: -16.5% to 17.2%; p =0.97). CONCLUSIONS: The documentation of risk assessment improved following the implementation of NICE guidance; it is questionable, however, whether this led to improved patient safety with respect to prescribing appropriate prophylaxis.


Assuntos
Quimioprevenção/estatística & dados numéricos , Fidelidade a Diretrizes , Segurança do Paciente/estatística & dados numéricos , Tromboembolia Venosa/prevenção & controle , Anticoagulantes/uso terapêutico , Contraindicações , Inglaterra , Heparina de Baixo Peso Molecular/uso terapêutico , Hospitais , Humanos , Medição de Risco , Fatores de Risco , Tromboembolia Venosa/epidemiologia
4.
N Engl J Med ; 368(19): 1771-80, 2013 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-23656642

RESUMO

BACKGROUND: The effectiveness of platelet transfusions to prevent bleeding in patients with hematologic cancers remains unclear. This trial assessed whether a policy of not giving prophylactic platelet transfusions was as effective and safe as a policy of providing prophylaxis. METHODS: We conducted this randomized, open-label, noninferiority trial at 14 centers in the United Kingdom and Australia. Patients were randomly assigned to receive, or not to receive, prophylactic platelet transfusions when morning platelet counts were less than 10×10(9) per liter. Eligible patients were persons 16 years of age or older who were receiving chemotherapy or undergoing stem-cell transplantation and who had or were expected to have thrombocytopenia. The primary end point was bleeding of World Health Organization (WHO) grade 2, 3, or 4 up to 30 days after randomization. RESULTS: A total of 600 patients (301 in the no-prophylaxis group and 299 in the prophylaxis group) underwent randomization between 2006 and 2011. Bleeding of WHO grade 2, 3, or 4 occurred in 151 of 300 patients (50%) in the no-prophylaxis group, as compared with 128 of 298 (43%) in the prophylaxis group (adjusted difference in proportions, 8.4 percentage points; 90% confidence interval, 1.7 to 15.2; P=0.06 for noninferiority). Patients in the no-prophylaxis group had more days with bleeding and a shorter time to the first bleeding episode than did patients in the prophylaxis group. Platelet use was markedly reduced in the no-prophylaxis group. A prespecified subgroup analysis identified similar rates of bleeding in the two study groups among patients undergoing autologous stem-cell transplantation. CONCLUSIONS: The results of our study support the need for the continued use of prophylaxis with platelet transfusion and show the benefit of such prophylaxis for reducing bleeding, as compared with no prophylaxis. A significant number of patients had bleeding despite prophylaxis. (Funded by the National Health Service Blood and Transplant Research and Development Committee and the Australian Red Cross Blood Service; TOPPS Controlled-Trials.com number, ISRCTN08758735.).


Assuntos
Neoplasias Hematológicas/terapia , Hemorragia/prevenção & controle , Transfusão de Plaquetas , Trombocitopenia/terapia , Adulto , Idoso , Antineoplásicos/uso terapêutico , Feminino , Neoplasias Hematológicas/complicações , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Transplante de Células-Tronco , Trombocitopenia/etiologia
5.
Blood Transfus ; 11(3): 419-25, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23058860

RESUMO

BACKGROUND: Premature babies may receive multiple transfusions during the first weeks of their life. Strong associations exist between the receipt of blood transfusions and the development of the major consequences of prematurity such as retinopathy and chronic lung disease. The possible physiological link between the receipt of blood and disease is unclear, but iron-induced oxidative damage and/or bacterial colonisation would promote these conditions. Premature babies are poorly equipped to deal with any increases in iron and oxidative load that they may acquire via blood transfusions. To determine whether there are any relationships between these factors, we studied iron and oxidative status of just expired (i.e. 36 days old) paediatric red blood cell (RBC) packs. MATERIALS AND METHODS: Just expired paediatric RBC packs were obtained from the local blood bank. The extracellular medium surrounding the RBC was separated by centrifugation and the following parameters measured: total iron concentration, total iron binding capacity, non-transferrin-bound iron [NTBI], haemoglobin, total and reduced ascorbate, and malondialdehyde concentration. RESULTS: The extracellular fluid of the paediatric packs (n =13) was rich in iron, a high percentage of which (36%) was present as potentially toxic NTBI. It was highly redox active with limited antioxidant protection and iron-binding capacity. DISCUSSION: The extracellular medium surrounding packed RBC could potentially be toxic if administered to patients with limited iron sequestering and antioxidant capacity, such as premature babies. Further studies are required to determine at what point during storage these changes become potentially harmful so that clinical studies can examine the optimal storage time for blood destined for premature babies.


Assuntos
Antioxidantes/metabolismo , Preservação de Sangue , Eritrócitos , Ferro/metabolismo , Estresse Oxidativo , Eritrócitos/citologia , Eritrócitos/metabolismo , Feminino , Humanos , Recém-Nascido , Masculino , Fatores de Tempo
6.
J Clin Oncol ; 31(3): 301-7, 2013 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-23233721

RESUMO

PURPOSE: Treatment options for patients with Waldenström macroglobulinemia (WM) and closely related disorders include alkylating agents, purine analogs, and monoclonal antibodies. No large randomized studies have yet been reported comparing any of these approaches. PATIENTS AND METHODS: The randomized WM1 study (Trial Comparing Chlorambucil to Fludarabine in Patients With Advanced Waldenström Macroglobulinemia) was undertaken in 101 centers in five countries enrolling 414 eligible patients (339 with WM, 37 with non-mucosa-associated lymphoid tissue marginal zone lymphoma, and 38 with lymphoplasmacytic lymphoma) who were randomly assigned to receive chlorambucil or fludarabine. The primary end point was the overall response rate (ORR). RESULTS: On the basis of intent-to-treat analysis, the ORR was 47.8% (95% CI, 40.9% to 54.8%) in the fludarabine arm versus 38.6% (95% CI, 32.0% to 45.7%) in the chlorambucil arm (P = .07). With a median follow-up of 36 months (interquartile range, 18 to 58 months), median progression-free survival (PFS), and duration of response (DR) were significantly improved in the fludarabine arm compared with the chlorambucil arm: PFS, 36.3 versus 27.1 months (P = .012) and DR, 38.3 versus 19.9 months (P < .001). In patients with WM, median overall survival (OS) was not reached in the fludarabine arm versus 69.8 months in the chlorambucil arm (95% CI, 61.6 to 79.8 months; P = .014). Grade 3 to 4 neutropenia was significantly higher among patients treated with fludarabine (36%) compared with patients treated with chlorambucil (17.8%; P < .001). Second malignancies were significantly more frequent in the chlorambucil arm with 6-year cumulative incidence rate of 20.6% versus 3.7% in the fludarabine arm (P = .001). CONCLUSION: In the complete intent-to-treat study population, fludarabine significantly improved PFS compared with chlorambucil, and in patients with WM, it improved OS.


Assuntos
Antineoplásicos/uso terapêutico , Clorambucila/uso terapêutico , Linfoma de Zona Marginal Tipo Células B/tratamento farmacológico , Vidarabina/análogos & derivados , Macroglobulinemia de Waldenstrom/tratamento farmacológico , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Linfoma de Zona Marginal Tipo Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Vidarabina/uso terapêutico , Macroglobulinemia de Waldenstrom/mortalidade
7.
Transfus Med Rev ; 24(3): 163-71, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20656185

RESUMO

Although considerable advances have been made in many aspects of platelet transfusion therapy in the last 30 years, some areas continue to provoke debate, including the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding in patients with bone marrow failure. We have designed a randomized controlled trial to compare prophylactic platelet use with a threshold of a platelet count of 10 x 10(9)/L with no prophylaxis in adult thrombocytopenic patients with hematologic malignancies. The trial question is whether a no-prophylactic policy for the use of platelet transfusions in patients with hematologic malignancies is not inferior to a threshold prophylactic policy at 10 x 10(9)/L, for bleeding at World Health Organization (WHO) grade 2, 3, or 4, up to 30 days from randomization. The primary outcome measure is the proportion of patients who have a significant clinical bleed, defined as WHO grade 2 or higher up to 30 days from randomization. Subsidiary clinical outcome measures include time to first bleed and a descriptive analysis of all severe bleeds. A bleeding assessment form is completed daily for all study subjects until day 30 from randomization. Minor modifications were made to the definitions at WHO grades 1 and 2 for petechiae and duration of nose bleeds, after piloting of the bleeding assessment forms. This study has been designed as a 2-stage randomized trial with an interim analysis planned after a minimum of 100 patients had been randomized and had completed their period of observation. Patients have initially been enrolled through 3 United Kingdom hematology centers. The interim analysis has been completed, and the results have confirmed a final sample size of 600 patients. Recruitment is now being extended to other centers in United Kingdom and Australia. Local research nurses are not blinded to treatment allocation, but a number of measures to reduce risk of assessment bias include repeated education around standard operating procedures, common definitions, and duplication of assessments. The expected completion date for the 5-year study is December 2011.


Assuntos
Neoplasias Hematológicas/complicações , Transfusão de Plaquetas , Trombocitopenia/terapia , Protocolos Clínicos , Neoplasias Hematológicas/terapia , Hemorragia/prevenção & controle , Humanos , Avaliação de Resultados em Cuidados de Saúde , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Trombocitopenia/etiologia
8.
Int J Cardiol ; 95(1): 83-8, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15159043

RESUMO

BACKGROUND: There is evidence for the activation of the coagulation system and a hypercoagulable state following cardioversion. The aim of the study was to determine whether electrical cardioversion in patients with chronic atrial fibrillation induced a prothrombotic state despite optimal anticoagulation. We studied the effects of electrical cardioversion on plasma levels of fibrinogen, antithrombin III, protein C and D-dimers. METHODS: We studied 24 patients with chronic atrial fibrillation who were on optimal anticoagulation and were referred for electrical cardioversion. Samples of venous blood were taken 2 h pre and post cardioversion and 1 month later. RESULTS: Plasma median concentrations of fibrinogen decreased significantly from 3.8 g/l (interquartile range 3.1-4.2 g/l) before cardioversion to 3.5 g/l (interquartile range 2.9-3.9 g/l) 2 h after cardioversion levels (P=0.004). The fibrinogen levels at 1 month post cardioversion (3.45 g/l, interquartile range 3.1-3.9 g/l) were also significantly lower than baseline (P=0.02). Plasma median levels of antithrombin III fell from 93.5 U/dl (interquartile range 89.3-97.0 U/dl) pre cardioversion to 89.5 U/dl (interquartile range 83.0-93.0 U/dl) 2 h after cardioversion (P=0.001) and returned to normal by 1 month (94.0 U/dl; interquartile range 89.3-98.5 U/dl; P=0.0001). There were no significant changes in plasma median D-dimer or protein C levels at any time. CONCLUSIONS: We have demonstrated a significant fall in the plasma fibrinogen and antithrombin III levels in patients with chronic atrial fibrillation early after electrical cardioversion, indicating thrombin generation. This study suggests that there are haemostatic changes of thrombogenesis induced by cardioversion despite optimal anticoagulation with warfarin.


Assuntos
Anticoagulantes/uso terapêutico , Fibrilação Atrial/sangue , Fibrilação Atrial/terapia , Coagulação Sanguínea/efeitos dos fármacos , Cardioversão Elétrica , Varfarina/uso terapêutico , Adulto , Idoso , Antitrombina III/efeitos dos fármacos , Antitrombina III/metabolismo , Biomarcadores/sangue , Doença Crônica , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/efeitos dos fármacos , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinogênio/efeitos dos fármacos , Fibrinogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Proteína C/efeitos dos fármacos , Proteína C/metabolismo , Resultado do Tratamento , Reino Unido
9.
Haematologica ; 88(11): 1272-8, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14607756

RESUMO

BACKGROUND AND OBJECTIVES: Patients with angioimmunoblastic T-cell lymphoma (AIL) have a poor prognosis with conventional treatment. DESIGN AND METHODS: We initiated an EBMT-based survey studying the impact of high-dose chemotherapy (HDCT) and autologous hematopoietic stem cell transplantation in patients with AIL. Data on 29 patients, who were transplanted between 1992 and 1998 in 16 transplant centers, were collected on standardized documentation forms. RESULTS: The median age at transplantation was 53 years. HDCT was given as part of 1st-line therapy (N=14; 48%) or 2nd/3rd-line therapy (N=15; 52%). Regimens for the mobilization of peripheral blood stem cells (PBSC) included VIPE (N=7; 26%), DexaBEAM (N=6; 22%), CHOP-like regimens (N=6; 22%), other regimens (N=5; 19%) or alternatively growth factor alone (N=3; 11%). The median yield of PBSC was 3.8x106 CD34+cells/kg. Two patients received autologous bone marrow. The HDCT consisted of BEAM-type regimens in 16 patients, ICE-type regimens in 7, and other regimens in 6 patients. There was one treatment-related death. The rate of complete remissions increased from 45% before HDCT to 76% after HDCT. As of January 2003, after a median observation time of living patients of 5 years (range 2.5 to 10 years), 14 patients have died (13 from progressive disease), and 15 patients are alive. The probability of 5-year overall and event-free survival was 44% (95% CI, 22% to 66%) and 37% (95% CI, 17% to 57%), respectively. Long-term disease-free survival was observed in patients transplanted during 1st-line treatment as well as in the context of 2nd/3rd-line therapy. INTERPRETATION AND CONCLUSIONS: There is evidence that AIL is susceptible to high-dose chemotherapy. HDCT and autologous stem cell transplantation should be considered in selected patients with AIL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfadenopatia Imunoblástica/tratamento farmacológico , Linfoma de Células T/tratamento farmacológico , Transplante de Células-Tronco de Sangue Periférico , Adulto , Terapia Combinada , Progressão da Doença , Intervalo Livre de Doença , Feminino , Inquéritos Epidemiológicos , Humanos , Linfadenopatia Imunoblástica/mortalidade , Linfadenopatia Imunoblástica/terapia , Tábuas de Vida , Linfoma de Células T/mortalidade , Linfoma de Células T/terapia , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Estudos Retrospectivos , Terapia de Salvação , Análise de Sobrevida , Condicionamento Pré-Transplante , Transplante Autólogo , Resultado do Tratamento
10.
Hematol J ; 4(4): 271-6, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12872152

RESUMO

We have previously shown that autologous dendritic cells (DCs) pulsed with tumour cell lysate and cultured with autologous T cells from patients with B-cell chronic lymphocytic leukaemia (B-CLL) stimulate significant increases in proliferation, IFN-gamma secretion and specific HLA class II-restricted cytotoxicity to B-CLL targets. In this study, normal and tumour cell lysates were analysed by reducing SDS-PAGE, and protein bands of interest eluted from the polyacrylamide gel by electroelution. The eluted protein fractions and whole-cell lysate were then pulsed onto autologous DCs and cocultured with autologous T cells. Finally, the stimulatory fractions were sequenced. B-CLL cell lysates revealed protein bands at 65, 42, 35 and 25 kDa, while normal B-cell lysates only showed a single protein band at 65 kDa. Both the 65 kDa band and 42 kDa bands were capable of stimulating comparable amounts of IFN-gamma secretion and specific cytotoxicity as whole lysate, while the other protein bands were not. Sequencing of the 65 kDa fraction showed a dominant peptide that matched human serum albumin, while sequencing the 42 kDa fraction showed three dominant peptides which matched human actin and another unidentified protein. The significance of these findings remains unclear.


Assuntos
Células Dendríticas/imunologia , Leucemia Linfocítica Crônica de Células B/imunologia , Proteínas de Neoplasias/imunologia , Linfócitos T Citotóxicos/imunologia , Actinas/imunologia , Actinas/isolamento & purificação , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Estudos de Casos e Controles , Extratos Celulares/imunologia , Células Cultivadas , Citotoxicidade Imunológica , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Interferon gama/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/isolamento & purificação , Albumina Sérica/imunologia , Albumina Sérica/isolamento & purificação , Transplante Autólogo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...