Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 130
Filtrar
1.
BMC Med Educ ; 18(1): 207, 2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-30185174

RESUMO

BACKGROUND: Current postgraduate medical training programmes fall short regarding residents' development of generic competencies (communication, collaboration, leadership, professionalism) and reflective and deliberate practice. Paying attention to these non-technical skills in a structural manner during postgraduate training could result in a workforce better prepared for practice. A development-oriented performance assessment (PA), which assists residents with assessment of performance and deliberately planned learning activities, could potentially contribute to filling this gap. This study aims to explore residents experiences with the PA. METHODS: We conducted a qualitative interview study with 16 residents from four different medical specialties who participated in the PA, scheduled halfway postgraduate training. The PA was conducted by an external facilitator, a psychologist, and focused specifically on professional development and career planning. Residents were interviewed 6 months after the PA. Data were analysed using the framework method for qualitative analysis. RESULTS: Residents found the PA to be of additional value for their training. The overarching merit was the opportunity to evaluate competencies not usually addressed in workplace-based assessments and progress conversations. In addition, the PA proved a valuable tool for assisting residents with reflecting upon their work and formulating their learning objectives and activities. Residents reported increased awareness of capacity, self-confidence and enhanced feelings of career-ownership. An important factor contributing to these outcomes was the relationship of trust with the facilitator and programme director. CONCLUSION: The PA is a promising tool in fostering the development of generic competencies and reflective and deliberate practice. The participating residents, facilitator and programme directors were able to contribute to a safe learning environment away from the busy workplace. The facilitator plays an important role by providing credible and informative feedback. Commitment of the programme director is important for the implementation of developmental plans and learning activities.


Assuntos
Avaliação Educacional , Internato e Residência , Competência Profissional , Escolha da Profissão , Comunicação , Currículo , Retroalimentação , Entrevistas como Assunto , Liderança , Países Baixos , Pesquisa Qualitativa
2.
Nutr Metab Cardiovasc Dis ; 24(8): 883-90, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24972558

RESUMO

BACKGROUND AND AIMS: Differences in blood fatty acids (FAs) profile among populations with different lifestyle have partly been attributed to differences in food intake. A holistic approach in dietary guidance through dietary patterns is essential. This study aimed at evaluating the main plasma and red blood cell (RBC) FAs in three European populations and assessing the role of dietary patterns in explaining variation in their levels. METHODS: In the framework of the IMMIDIET Project, 1604 subjects (802 male-female pairs) aged 26-65 years were enrolled in Italy, Belgium and UK. Plasma and RBC FAs were measured. One year recall food frequency questionnaires were used to evaluate dietary habits of each individual. RESULTS: Italian cohort showed lower plasma and RBC n-3 levels than participants of the other two populations (P<0.001). Both plasma and RBC arachidonic acid were higher in Italian cohort as compared to Belgian and English. Reduced rank regression analysis indicated two dietary patterns explaining 35% and 17% of the total variation of the sum of plasma and RBC n-3, respectively. In a holistic dietary analysis, neither fish nor mollusks intake seemed to contribute to n-3 variation as compared to vegetable oils and polyphenol-rich foods. CONCLUSION: The Italian cohort presented significant lower plasma and RBC n-3 FA levels compared to Belgians and English. A holistic approach in dietary analysis seemed to explain a relatively high proportion of plasma and RBC n-3 FAs variability. Dietary pattern analysis may contribute to the study of the association of human diet with FAs levels.


Assuntos
Ácido Araquidônico/sangue , Ácidos Graxos Ômega-3/sangue , Comportamento Alimentar , Adulto , Idoso , Bélgica , Índice de Massa Corporal , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Transversais , Dieta , Eritrócitos/química , Feminino , Humanos , Itália , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Avaliação Nutricional , Estudos Prospectivos , Inquéritos e Questionários , Triglicerídeos/sangue , Reino Unido
3.
Nutr Metab Cardiovasc Dis ; 22(6): 517-24, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21193294

RESUMO

BACKGROUND AND AIMS: The European 'IMMIDIET' study was designed to evaluate the effect of genetic and dietary habit interactions on cardiovascular disease risk factors in non-diabetic subjects. Copper, zinc and selenium are involved in redox balance and modifications of their homeostasis could be associated with metabolic syndrome. Because few studies have dealt with trace element status in metabolic syndrome with conflicting results, we aimed at investigating the relationships between plasma copper, zinc and selenium concentrations and metabolic syndrome in the IMMIDIET population. METHODS AND RESULTS: Male-female couples born and living in Abruzzo, Italy (n = 271); Limburg, Belgium (n = 267), southwest part of London, England (n = 263) and 205 Italian-Belgian mixed couples living in Belgium were enrolled. Data on medical history, hypertension and blood lipid profile, medication use, smoking and alcohol habits, physical activity and socioeconomic status were collected using a standardised questionnaire. Anthropometric, blood pressure, glucose, insulin, lipid profile and copper, zinc and selenium measurements were performed. Participants were classified in two groups according to the presence of metabolic syndrome (Yes/No). Comparison between these two groups, performed separately in men and women, indicated no association in men whereas, in women, metabolic syndrome was associated with higher plasma selenium concentrations (odds ratio (OR) = 1.55(1.28-1.89)); this association remained significant after adjustment for age, group, social status, physical activity, energy intake, alcohol consumption, smoking and hormonal status (OR = 1.33 (1.06-1.67)). CONCLUSION: Our results indicate gender differences in the association between plasma selenium concentration and metabolic syndrome without diabetes and may suggest a sub-clinical deleterious effect of high selenium status in women.


Assuntos
Cobre/sangue , Comportamento Alimentar , Síndrome Metabólica/epidemiologia , Selênio/sangue , População Branca/genética , Zinco/sangue , Adulto , Consumo de Bebidas Alcoólicas , Antropometria , Bélgica/epidemiologia , Estudos Transversais , Diabetes Mellitus , Ingestão de Energia , Feminino , Humanos , Hipertensão/complicações , Hipertensão/epidemiologia , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Itália/epidemiologia , Lipídeos/sangue , Londres/epidemiologia , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/genética , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Razão de Chances , Fatores Sexuais , Fumar , Inquéritos e Questionários
4.
Scand J Med Sci Sports ; 21(4): 526-34, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20459467

RESUMO

We reported previously that two otherwise identical training programs at lower (LI) and higher intensity (HI) similarly reduced resting systolic blood pressure (BP) by approximately 4-6 mmHg. Here, we determined the effects of both programs on BP-regulating mechanisms, on biomarkers of systemic inflammation and prothrombotic state and on the heart. In this cross-over study (3 × 10 weeks), healthy participants exercised three times 1 h/week at, respectively, 33% and 66% of the heart rate (HR) reserve, in a random order, with a sedentary period in between. Measurements, performed at baseline and at the end of each period, involved blood sampling, HR variability, systolic BP variability (SBPV) and cardiac magnetic resonance imaging. Thirty-nine participants (18 men; mean age 59 years) completed the study. Responses were not different between both programs (P>0.05). Pooled data from LI and HI showed a reduction in HR (-4.3 ± 8.1%) and an increase in stroke volume (+11 ± 23.1%). No significant effect was seen on SBPV, plasma renin activity, basal nitric oxide and left ventricular mass. Our results suggest that the BP reduction observed appears to be due to a decrease in systemic vascular resistance; training intensity does not significantly affect the results on mechanisms, biomarkers and the heart.


Assuntos
Biomarcadores , Pressão Sanguínea/fisiologia , Exercício Físico/fisiologia , Coração , Estudos Cross-Over , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Resistência Física/fisiologia , Volume Sistólico/fisiologia
5.
Vox Sang ; 99(3): 251-60, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20840339

RESUMO

BACKGROUND: Fresh frozen plasma (FFP) and prothrombin complex concentrates (PCC) reverse oral anticoagulants. We compared PCC and FFP intraoperative administration in patients undergoing heart surgery with cardiopulmonary bypass (CPB). METHODS: Forty patients [with international normalized ratio (INR)≥ 2·1] assigned semi-urgent cardiac surgery were randomized to receive either FFP (n = 20) or PCC (n = 20). Prior to CPB, they received either 2 units of FFP or half of the PCC dose calculated according to body weight, initial INR and target INR ( ≤ 1·5). After CPB and protamine administration, patients received either another 2 units of FFP or the other half PCC dose. Additional doses were administered if INR was still too high ( ≥ 1·5). RESULTS: Fifteen minutes after CPB, more patients reached INR target with PCC (P = 0·007): 7/16 patients vs. 0/15 patients with FFP; there was no difference 1 h after CPB (6/15 patients with PCC vs. 4/15 patients with FFP reached target). Fifteen minutes after CPB, median INR (range) decreased to 1·6 (1·2-2·2) with PCC vs. 2·3 (1·5-3·5) with FFP; 1 h after CPB both groups reached similar values [1·6 (1·3-2·2) with PCC and 1·7 (1·3-2·7) with FFP]. With PCC, less patients needed additional dose (6/20) than with FFP (20/20) (P < 0·001). Both groups differed significantly on the course of factor II (P = 0·0023) and factor X (P = 0·008) over time. Dilution of coagulation factors was maximal at CPB onset. Safety was good for both groups, with only two related oozing cases with FFP. CONCLUSION: PCC reverses anticoagulation safely, faster and with less bleeding than FFP.


Assuntos
Anticoagulantes/administração & dosagem , Fatores de Coagulação Sanguínea/administração & dosagem , Ponte Cardiopulmonar , Coeficiente Internacional Normatizado , Plasma , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
J Thromb Haemost ; 8(7): 1540-6, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20345724

RESUMO

SUMMARY BACKGROUND: Anticardiolipin (aCL) and anti-beta(2)glycoprotein I (abeta(2)GPI) antibodies are part of the criteria for antiphospholipid syndrome (APS). Therefore they are widely measured and about 30 commercial kits are available. OBJECTIVES: To investigate the analytical and clinical performances of four fully automated, chemiluminescent assays: HemosIL AcuStar aCL IgG, HemosIL AcuStar aCL IgM, HemosIL AcuStar abeta(2)GPI IgG, and HemosIL AcuStar abeta(2)GPI IgM. METHODS: Cut-off values were assessed by testing 250 blood donors. Total coefficients of variation (CV) were determined with six plasma pools and two controls ranging from 4.3 to 2694 U mL(-1) depending on the assay. Samples from 218 well-characterized patients and 103 controls were measured in three laboratories to determine inter-laboratory variation. The results of the 321 samples were compared with three commercial assays (REAADS, INOVA and VARELISA). RESULTS: Cut-off values were assigned to 20 arbitrary units for all the tests. Total CV ranged from 4.3 to 11.2%. No interference of hemoglobin, bilirubin, triglycerides, heparins and rheumatoid factor was observed. Inter-laboratory variability was low and no sample changed status. Overall status agreement between HemosIL assays and the comparator kits ranged from 82 to 96%. Sensitivity, specificity, agreement when predicting APS and the odds ratios when predicting a thrombotic or obstetric event gave comparable results between HemosIL AcuStar and the three other assays. CONCLUSIONS: Our study demonstrates that the fully automated HemosIL AcuStar aPL assay panel showed similar performances to the three commercial ELISAs commonly used by various laboratories to detect antiphospholipid antibodies.


Assuntos
Anticorpos Antifosfolipídeos/sangue , Síndrome Antifosfolipídica/diagnóstico , Kit de Reagentes para Diagnóstico/normas , Feminino , Humanos , Medições Luminescentes/normas , Masculino , Variações Dependentes do Observador , Valor Preditivo dos Testes , Gravidez , Complicações Hematológicas na Gravidez , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Trombose
7.
Radiother Oncol ; 93(3): 447-53, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19765847

RESUMO

BACKGROUND AND PURPOSE: To determine the consequences of target volume (TV) modifications, based on the additional use of PET information, on radiation planning, assuming PET/CT-imaging represents the true extent of the tumour. MATERIALS AND METHODS: For 21 patients with esophageal cancer, two separate TV's were retrospectively defined based on CT (CT-TV) and co-registered PET/CT images (PET/CT-TV). Two 3D-CRT plans (prescribed dose 50.4 Gy) were constructed to cover the corresponding TV's. Subsequently, these plans were compared for target coverage, normal tissue dose-volume histograms and the corresponding normal tissue complication probability (NTCP) values. RESULTS: The addition of PET led to the modification of CT-TV with at least 10% in 12 of 21 patients (57%) (reduction in 9, enlargement in 3). PET/CT-TV was inadequately covered by the CT-based treatment plan in 8 patients (36%). Treatment plan modifications resulted in significant changes (p<0.05) in dose distributions to heart and lungs. Corresponding changes in NTCP values ranged from -3% to +2% for radiation pneumonitis and from -0.2% to +1.2% for cardiac mortality. CONCLUSIONS: This study demonstrated that TV's based on CT might exclude PET-avid disease. Consequences are under dosing and thereby possibly ineffective treatment. Moreover, the addition of PET in radiation planning might result in clinical important changes in NTCP.


Assuntos
Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/radioterapia , Carcinoma de Células Escamosas/diagnóstico por imagem , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/radioterapia , Tomografia por Emissão de Pósitrons , Planejamento da Radioterapia Assistida por Computador , Idoso , Carcinoma de Células Escamosas/radioterapia , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos , Dosagem Radioterapêutica , Radioterapia Conformacional , Tomografia Computadorizada por Raios X
9.
J Thromb Haemost ; 6(3): 436-43, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18036188

RESUMO

AIM: Differences in C-reactive protein (CRP) levels and its determinants in three European populations at different risk of coronary artery disease (CAD) were studied. METHODS: Subjects were recruited randomly in Limburg (Belgium), Abruzzo (Italy) and south-west (SW) London (England). RESULTS: Ten-year risk of fatal coronary events (estimated using risk equations provided by the SCORE Project) was lower both in men and women from Abruzzo, intermediate in people from Limburg and higher in subjects from SW London. Within each country, high sensitivity (hs)-CRP levels were higher in the high-risk class in men but not in women. Men from Abruzzo had higher hs-CRP levels than those from Limburg and SW London. Women always had higher hs-CRP levels than men. The strongest hs-CRP determinant was body mass index (BMI, R(2) = 0.14) in women and waist circumference (WC, R(2) = 0.046) in men. The highest hs-CRP levels were observed in subjects with both high BMI and high WC. Metabolic syndrome was associated with high levels of CRP both in men and women, even after adjustment for confounders. DISCUSSION: Difference in CRP levels cannot explain the European gradient of CVD risk, although CRP levels are associated with the calculated SCORE risk of fatal coronary events within each country.


Assuntos
Proteína C-Reativa/biossíntese , Doença das Coronárias/sangue , Adulto , Idoso , Composição Corporal , Índice de Massa Corporal , Europa (Continente) , Feminino , Humanos , Masculino , Síndrome Metabólica/sangue , Pessoa de Meia-Idade , Valores de Referência , Risco , População Branca
10.
Am J Transplant ; 7(9): 2195-9, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17640311

RESUMO

Fractionated Plasma Separation and Adsorption (FPSA) is a novel nonbiologic detoxification system for the removal of protein-bound solutes. FPSA is used to bridge patients during fulminant liver failure, either to functional recovery or to liver transplantation. Besides liver failure associated protein bound solutes, several important uremic retention solutes share important protein binding. We observed repeated occlusive thrombosis of the arterio-venous conduit during FPSA in hemodialysis (HD) patients, resulting in acute loss of function. A major reduction of several coagulation factors was demonstrated, exceeding 50% for factor II, factor X and protein C. Broad disturbances of the coagulation system were confirmed in FPSA treated liver failure patients. An ex vivo recirculation model demonstrated nonspecific adsorption of coagulation factors protein S and protein C on the anion exchange cartridge. Direct contact between fractionated plasma and the Prometh02 anion exchanger causes significant adsorption of procoagulant and anti-coagulant factors, associated with clinically relevant adverse events.


Assuntos
Falência Renal Crônica/terapia , Falência Hepática Aguda/terapia , Plasmaferese/efeitos adversos , Trombose/etiologia , Adolescente , Adsorção , Adulto , Idoso , Estudos Cross-Over , Ensaio de Imunoadsorção Enzimática , Fator X/metabolismo , Seguimentos , Humanos , Falência Renal Crônica/sangue , Falência Hepática Aguda/sangue , Pessoa de Meia-Idade , Plasmaferese/instrumentação , Prognóstico , Proteína C/metabolismo , Protrombina/metabolismo , Diálise Renal , Estudos Retrospectivos , Trombose/sangue
12.
Biomaterials ; 28(12): 2122-6, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17258314

RESUMO

Pin tract infections of external fixators used in orthopaedic reconstructive bone surgery are serious complications that can eventually lead to periostitis and osteomyelitis. In vitro experiments have demonstrated that bacteria adhering to stainless steel in a biofilm mode of growth detach under the influence of small electric currents, while remaining bacteria become less viable upon current application. Therefore, we have investigated whether a 100microA electric current can prevent signs of clinical infection around percutaneous pins, implanted in the tibia of goats. Three pins were inserted into the lateral right tibia of nine goats, of which one served for additional frame support. Two pins were infected with a Staphylococcus epidermidis strain of which one pin was subjected to electric current, while the other pin was used as control. Pin sites were examined daily. The wound electrical resistance decreased with worsening of the infection from a dry condition to a purulent stage. After 21 days, animals were sacrificed and the pins taken out. Infection developed in 89% of the control pin sites, whereas only 11% of the pin sites in the current group showed infection. These results show that infection of percutaneous pin sites of external fixators in reconstructive bone surgery can be prevented by the application of a small DC electric current.


Assuntos
Eletricidade , Fixadores Externos , Modelos Animais , Modelos Biológicos , Aço Inoxidável , Infecção da Ferida Cirúrgica/prevenção & controle , Animais , Eletrodos , Cabras , Staphylococcus epidermidis/isolamento & purificação , Infecção da Ferida Cirúrgica/microbiologia
13.
J Thromb Haemost ; 5(1): 1-4, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17026649

RESUMO

Many investigators have been intrigued by the paradoxical association of a circulating anticoagulant, first called lupus anticoagulant by Feinstein and Rapaport [1], with a tendency to develop thrombosis, as initially described by Walter Bowie [2]. Work in Leuven on this topic started when Luis Carreras, an Argentinian hematologist, joined the laboratory of blood coagulation at this university in 1979. At that time, the head of the laboratory was Marc Verstraete. Luis had a particular interest in antibody-mediated coagulation disorders, and had prepared reviews on thrombosis and thrombocytopenia induced by heparin [3] and on the lupus inhibitor [4]. In Leuven, he joined Jos Vermylen, senior member of the laboratory, and an internist with particular interest in hemostasis, thrombosis and vascular disease. As such, Professor Vermylen was involved in both laboratory research and patient care.


Assuntos
Síndrome Antifosfolipídica/história , Pesquisa Biomédica/história , Hematologia/história , Complicações Hematológicas na Gravidez/história , Animais , Anticorpos Anticardiolipina/história , Síndrome Antifosfolipídica/imunologia , Síndrome Antifosfolipídica/metabolismo , Epoprostenol/história , Feminino , História do Século XX , Humanos , Fragmentos Fc das Imunoglobulinas/história , Inibidor de Coagulação do Lúpus/história , Ativação Plaquetária , Gravidez , Complicações Hematológicas na Gravidez/imunologia , Complicações Hematológicas na Gravidez/metabolismo , Trombose/história , beta 2-Glicoproteína I/história
14.
Acta Clin Belg ; 61(4): 183-7, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17091916

RESUMO

The association between Hodgkin's lymphoma, antiphospholipid syndrome and severe mitral insufficiency is a very rare event. We report on a 25-year-old female patient suffering from Hodgkin's lymphoma and presenting with thromboembolic events and severe mitral insufficiency. The possible link between these symptoms being antiphospholipid antibodies, is discussed briefly.


Assuntos
Síndrome Antifosfolipídica/complicações , Doença de Hodgkin/complicações , Insuficiência da Valva Mitral/complicações , Adulto , Feminino , Humanos
15.
Handb Exp Pharmacol ; (176 Pt 2): 1-41, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17001771

RESUMO

When the continuity of the vascular endothelium is disrupted, platelets and fibrin seal off the defect. Haemostatic processes are classified as primary (mainly involving platelets) and secondary (mainly related to fibrin formation or blood coagulation). When the blood clot is no longer required for haemostasis, the fibrinolytic system will dissolve it. The pivotal ligand for initial platelet recruitment to injured vessel wall components is von Willebrand factor (vWF), a multimeric protein present in the subendothelium and in plasma, where it is conformationally activated by shear forces. Adhering activated platelets recruit additional platelets, which are in turn activated and form a platelet aggregate. Coagulation is initiated by a reaction, activating factors IX and X. Once critical amounts of factor Xa are generated, thrombin generation is initiated and soluble fibrinogen is converted into insoluble fibrin. Excessive thrombin generation is prevented via inhibition by antithrombin and also via downregulation of its further generation by activation of the protein C pathway. Activation of the fibrinolytic system results from conversion of the proenzyme plasminogen into the active serine proteinase plasmin by tissue-type or urokinase-type plasminogen activators. Plasmin digests the fibrin component of a blood clot. Inhibition of the fibrinolytic system occurs at the level of the plasminogen activator (by plasminogen activator inhibitors) or at the level of plasmin (by alpha2-antiplasmin). Together, these physiological processes act to maintain normal functioning blood vessels and a non-thrombotic state.


Assuntos
Coagulação Sanguínea , Plaquetas/fisiologia , Endotélio Vascular/fisiologia , Hemostasia , Animais , Arteriopatias Oclusivas/sangue , Arteriopatias Oclusivas/metabolismo , Plaquetas/metabolismo , Endotélio Vascular/metabolismo , Fibrinólise , Humanos , Plasminogênio/metabolismo , Ativadores de Plasminogênio/metabolismo , Agregação Plaquetária , Glicoproteínas da Membrana de Plaquetas/metabolismo , Receptores de Colágeno/metabolismo , Tromboplastina/metabolismo
17.
J Thromb Haemost ; 2(12): 2178-84, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15613024

RESUMO

We report here results from a United Kingdom National Quality Assessment Scheme (UK NEQAS) exercise in which both plasma spiked with monoclonal antibodies and plasma from a patient known to have lupus anticoagulant (LA) were distributed to 245 hemostasis laboratories with a request for them to test for possible LA using their routine screening procedure. In general, good agreement was seen in the diagnosis of samples spiked with monoclonal antibodies against beta2-glycoprotein 1 (beta2GP1) and prothrombin, the LA-positive patient sample, and a normal pooled plasma; over 87% of centers correctly identified each sample. However, methods employing platelet neutralizing procedures were associated with a higher proportion of false-negative responses with the antiprothrombin-spiked sample, and it is important to recognize that sensitivity and responsiveness of different methods may vary between artificial plasmas and different LA-positive patient plasmas.


Assuntos
Anticorpos Monoclonais/química , Testes de Coagulação Sanguínea/métodos , Laboratórios/normas , Inibidor de Coagulação do Lúpus/análise , Inibidor de Coagulação do Lúpus/sangue , Algoritmos , Glicoproteínas/química , Humanos , Tempo de Tromboplastina Parcial , Protrombina/química , Controle de Qualidade , Reprodutibilidade dos Testes , Tromboplastina/biossíntese , Fatores de Tempo , Reino Unido , Tempo de Coagulação do Sangue Total , beta 2-Glicoproteína I
18.
Appl Environ Microbiol ; 70(11): 6871-4, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15528555

RESUMO

Biomaterial-centered infections of orthopedic percutaneous implants are serious complications which can ultimately lead to osteomyelitis, with devastating effects on bone and surrounding tissues, especially since the biofilm mode of growth offers protection against antibiotics and since removal frequently is the only ultimate solution. Recently, it was demonstrated that as a possible pathway to prevent infections of percutaneous stainless steel implants, electric currents of 60 to 100 microA were effective at stimulating the detachment of initially adhering staphylococci from surgical stainless steel. However, initially adhering bacteria are known to adhere more reversibly than bacteria growing in the later stages of biofilm formation. Hence, the aim of this study was to examine whether a growing Staphylococcus epidermidis biofilm can be stimulated to detach from surgical stainless steel by the use of electric currents. In separate experiments, four currents, i.e., 60 and 100 microA of direct current (DC) and 60 and 100 microA of block current (50% duty cycle, 1 Hz), were applied for 360 min to stimulate the detachment of an S. epidermidis biofilm that had grown for 200 min. A 100-microA DC yielded 78% detachment, whereas a 100-microA block current under the same experimental conditions yielded only 31% detachment. The same trend was found for 60 microA, with 37% detachment for a DC and 24% for a block current. Bacteria remaining on the surface after the current application were less viable than they were prior to the current application, as demonstrated by confocal laser scanning microscopy. In conclusion, these results suggest that DCs are preferred for curing infections.


Assuntos
Biofilmes/crescimento & desenvolvimento , Eletricidade , Infecções Relacionadas à Prótese/prevenção & controle , Aço Inoxidável , Staphylococcus epidermidis/fisiologia , Aderência Bacteriana , Cirurgia Geral/instrumentação , Humanos , Microscopia Confocal , Próteses e Implantes , Infecções Estafilocócicas/prevenção & controle , Staphylococcus epidermidis/crescimento & desenvolvimento
19.
Curr Med Chem ; 11(17): 2245-60, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15379710

RESUMO

The hemostatic system comprises platelet aggregation, coagulation and fibrinolysis also termed primary, secondary and tertiary hemostasis. From the platelet transcriptome 6000 mRNA species and represent receptors, ion channels, signalling molecules, kinases, phosphatases, and structural, metabolic and regulatory proteins. This abundance of regulatory proteins points towards the importance of signal transduction in platelet function. First platelets adhere to collagen, this induces activation signals such as TXA(2) that induces further Ca(2+) increase. Consecutively, fibrinogen binds to the integrin alpha(IIb)beta(3) resulting in aggregation.This self-amplifying process is controlled by signals, from endothelial cells, to restrict the platelet plug to the site of vessel injury. Secondary hemostasis (coagulation) consists of an extrinsic and intrinsic pathway. Thrombin is generated via Factor Xa resulting from the extrinsic tenase reaction that is turned of by tissue factor pathway inhibitor. While thrombin generation is maintained via positive feedback mechanisms activating factors V, VIII and XI. Excess thrombin is inhibited by antithrombin or by autodownregulation via activation of protein C. Since minor injuries are common, platelets and plasma clotting factors constantly produce clots to stop bleeding. If clots remained after the tissue healing, the vascular bed would become obstructed with clots therefore this is regulated by fibrinolysis, tertiary hemostasis. Tissue-type plasminogen activator synthesised by the endothelium, converts plasminogen to plasmin, the clot lysis enzyme. Plasmin clears the blood vessels by degrading fibrin. Fibrinolysis is controlled by plasminogen activators inhibitor (PAI-1), alpha2-antiplasmin and alpha2-macroglobulin, and thrombin-activatable fibrinolysis inhibitor (TAFI).


Assuntos
Fibrina/fisiologia , Hemostasia/fisiologia , Antifibrinolíticos/farmacologia , Fatores de Coagulação Sanguínea/metabolismo , Plaquetas/efeitos dos fármacos , Plaquetas/fisiologia , Fibrinólise/fisiologia , Hemostasia/efeitos dos fármacos , Humanos , Adesividade Plaquetária/fisiologia , Agregação Plaquetária/fisiologia , Transdução de Sinais/fisiologia , Trombose/etiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...