587 research outputs found
Low-Dose Aspirin, Coxibs, and other NSAIDS: A clinical Mosaic Emerges.
No full textAspirin has been a commercial drug for over a century, although for most of this history, an understanding of its mechanism of action, as an inhibitor of cyclooxygenase (COX) activity and thus of prostanoid synthesis, was lacking. Over the past fifty years, a large number of other nonsteroidal antiinflammatory drugs (NSAIDs) have been developed, and a much deeper understanding of inflammation and prostanoid action has emerged. Indeed, a new class of selective inhibitors of the cyclooxygenase-2 isozyme was introduced, about ten years ago, and these so-called coxibs quickly became regarded as preferable, in certain clinical contexts, to avoid side effects associated with the use of aspirin and previously developed NSAIDs. This regard for coxibs has been challenged, sometimes infamously, as cardiovascular events associated with coxib use have become apparent. A variety of clinical trials have led to seemingly conflicting data concerning the roles of COX-1 and COX-2, and the implications of their relative inhibition, in cardiovascular health and disease. In this Review, the authors offer an assessment of drug pharmacokinetics and enzyme physiology that reconciles cardiovascular appraisals from a wide array of clinical data
Antiplatelet therapy:aspirin for asymptomatic atherosclerosis?
No full textThe ankle–brachial index (ABI) is calculated as the ratio of the lowest ankle blood pressure (the lowest value measured from the posterior tibial and dorsalis pedis arteries in both legs) to the higher of the pressure values measured in either arm. Values below about 0
Nonsteroidal anti-inflammatory drugs and the heart
No full textAspirin has been on the market for 115 years. Beginning with the marketing of indomethacin for the treatment of rheumatoid arthritis in 1963, at least 20 other nonsteroidal anti-inflammatory drugs (NSAIDs) with aspirin-like actions have been developed over the past 50 years,1 culminating with the introduction of a new class of selective inhibitors of cyclooxygenase (COX)-2, the coxibs, approximately 15 years ago.2 The NSAIDs represent the single most crowded family of drugs sharing the same therapeutic activities and mechanism of action, perhaps reflecting the unmet therapeutic need in the area of pain management and the large interindividual variability in response to these agents. NSAIDs provide symptomatic relief of pain and inflammation associated with a variety of human disorders, including the rheumatic diseases. Their shared therapeutic actions (ie, analgesic, anti-inflammatory, and antipyretic) are usually accompanied by mechanism-based adverse effects that can, at least in part, be attenuated as a function of individual pharmacokinetic or pharmacodynamic properties.
Coxibs, Traditional NSAIDs, and Cardiovascular Safety Post-PRECISION: What We Thought We Knew Then and What We Think We Know Now
No full textThe aim of the present review is to analyze how thinking about the cardiovascular safety of nonsteroidal antiinflammatory drugs has evolved during the past two decades, and discuss to what extent the additional information from the Prospective Randomized Evaluation of Celecoxib Integrated Safety Versus Ibuprofen or Naproxen study may alter our current mechanistic understanding and/or clinical practice
Antiplatelet Drugs: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)
No full textThis article about currently available antiplatelet drugs is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). It describes the mechanism of action, pharmacokinetics, and pharmacodynamics of aspirin, reversible cyclooxygenase inhibitors, thienopyridines, and integrin alphaIIbbeta3 receptor antagonists. The relationships among dose, efficacy, and safety are thoroughly discussed, with a mechanistic overview of randomized clinical trials. The article does not provide specific management recommendations; however, it does highlight important practical aspects related to antiplatelet therapy, including the optimal dose of aspirin, the variable balance of benefits and hazards in different clinical settings, and the issue of interindividual variability in response to antiplatelet drugs
Avaliação da cultivar de macieira Baigent (Brookfield®) em Vacaria, RS.
No full textO objetivo desse documento é apresentar os resultados de seis anos de avaliação da cultivar Baigent, com o intuito de oferecer aos produtores informações capazes de subsidiar a escolha de cultivares para a implantação de novos pomares e disponibilizar os resultados da pesquisa a todos os interessados
Maturation of 'Baigent' apples protected by anti hail nets and sprayed with aminoethoxyvinylglycine and ethephon.
No full textABSTRACT - The objective of this work was to evaluate the effect of pre‑harvest spraying with aminoethoxyvinylglycine (AVG) and ethephon on fruit maturation of 'Baigent' apple (Malus domestica) trees grown under black anti‑hail nets. The treatments were: control; 125 mg L-¹ AVG, sprayed 30 days before anticipated harvest time (DBAH); 120 mg L-¹ ethephon 7 DBAH; 62.5 mg L-¹ + 62.5 mg L-¹ AVG 30 and 20 DBAH; and 62.5 mg L-¹ + 62.5 mg L-¹ AVG 30 and 20 DBAH + 120 mg L-¹ ethephon 7 DBAH. Fruit were harvested in the commercial harvest of the control treatment (harvest 1) and 14 days later (harvest 2). Yellowing and loss of firmness were delayed by the treatments with AVG and accelerated by that with ethephon. AVG application in a single rate of 125 mg L-¹ 30 DBAH or in two split rates of 62.5 mg L-¹ 30 and 20 DBAH delays fruit maturation. The pre-harvest application of AVG in a single rate reduces the red color of the fruits, which is not affected by application in split rates, combined or not with ethephon, regardless of the date of harvest. RESUMO - O objetivo deste trabalho foi avaliar o efeito da pulverização pré-colheita com aminoetoxivinilglicina (AVG) e etefon sobre a maturação dos frutos de macieiras 'Baigent' (Malus domestica) produzidas sob tela antigranizo preta. Os tratamentos foram: controle; 125 mg L-¹ de AVG, aplicados 30 dias antes da colheita dos frutos não tratados (DAPC); 120 mg L-¹ de etefon 7 DAPC; 62,5 mg L-¹ + 62,5 mg L-¹ de AVG 30 e 20 DAPC; e 62,5 mg L-¹ + 62,5 mg L-¹ de AVG 30 e 20 DAPC + 120 mg L-¹ de etefon 7 DAPC. Os frutos foram colhidos na colheita comercial do tratamento-controle (colheita 1) e após 14 dias (colheita 2). O amarelecimento e a perda de firmeza foram retardados pelos tratamentos com AVG e acelerados pelo com etefon. A aplicação de AVG em dose única de 125 mg L-¹ 30 DAPH ou em duas doses de 62,5 mg L-¹ 30 e 20 DAPH retarda a maturação dos frutos. A aplicação précolheita de AVG em dose única reduz a coloração vermelha dos frutos, que não é afetada pela aplicação em dose dividida, combinada ou não com etefon, independentemente da data de colheita.Título em português: Maturação de maçãs 'Baigent' produzidas sob tela antigranizo e pulverizadas com aminoetoxivinilglicina e etefon
Desenvolvimento da coloração vermelha e conteúdo de antocianinas na película de maçãs 'imperial Gala' e 'Baigent'.
No full textOs clones do grupo Gala representam mais que50% das maçãs produzidas no Brasil. Os produtores estão buscando cultivares com maior intensidade e cobertura de coloração vermelha. Esses frutos são mais atrativos e despertam o interesse dos consumidores, agregando valor ao produto. Espera-se que esses frutos possuam maior concentração de antocianinas na película em função da maior coloração. Logo, oobjetivo do trabalho foi avaliar a evolução da cor dos frutos de Imperial Gala e Baigent (BrookfieldTM)por meio do ângulo hue(°h), concentração de antocianinas e porcentagem de recobrimento, cultivados em São Joaquim-SC.XVI ENFRUTE 201
Towards evidence-based guidelines for the prevention of venous thromboembolism: systematic reviews of mechanical methods, oral anticoagulation, dextran and regional anaesthesia as thromboprophylaxis
No full textObjectivesThe objectives of this study were to assess the benefits in terms of reductions in the risks of deep vein thrombosis (DVT) and of pulmonary embolism (PE), and hazards in terms of major bleeding, of: (i) mechanical compression (graduated compression stockings, intermittent pneumatic compression, footpumps); (ii) oral anticoagulants; (iii) dextran; and (iv) regional anaesthesia (as an alternative to general anaesthesia) in surgical and medical patients.Search strategyThe strategy involved a systematic search of electronic databases (MEDLINE, EMBASE, BIOSIS, Derwent), search of the Antithrombotic Trialists’ Collaboration database, contact with trialists and manufacturers, and scrutiny of bibliographies of identified papers and reviews of thromboprophylaxis.Selection criteriaProperly randomised trials were selected, including those reported in a non-English language, with at least one unconfounded comparison of the effect of one of the methods under review versus control, or a direct comparison between different versions of a method, or a direct comparison between a pharmacological agent (dextran or an oral anticoagulant) and low molecular weight or unfractionated heparin. Trials were included only if systematic assessment of DVT by radiological methods was planned.Data collection and analysisAll trials identified as fitting the selection criteria were independently assessed by at least two review authors for methodological quality and the numbers of patients with primary and secondary outcomes were recorded. The primary outcomes were DVT, PE and major bleeding events, and proximal venous thrombosis (PVT) and fatal PE were secondary outcomes. Trials were subdivided into those that had assessed a method as the only means of thromboprophylaxis (‘monotherapy’) and those that had assessed the effects of adding a method to another form of thromboprophylaxis (‘adjunctive therapy’).Main resultsMechanical compression methods reduced the risk of DVT by about two-thirds when used as monotherapy and by about half when added to a pharmacological method. These benefits were similar irrespective of the particular method used (graduated compression stockings, intermittent pneumatic compression or footpumps) and similar in each of the surgical groups studied. Mechanical methods reduced the risk of PVT by about half and the risk of PE by two-fifths.Oral anticoagulants, when used as monotherapy, reduced the risk of DVT and of PVT by about half, and this protective effect appeared similar in each of the surgical groups studied. There was an apparently large four-fifths reduction in the role of PE, but not only was the magnitude of this reduction statistically uncertain, but also pulmonary embolism was reported by a minority of trials, so it may be subject to selection bias. Oral anticoagulant regimens approximately doubled the risk of major bleeding. Oral anticoagulant regimens appeared less effective at preventing DVT than heparin regimens [64% (standard error [SE] 8) greater risk of DVT], although were associated with less major bleeding [35% (10) risk reduction for major bleeds].Dextran reduced the risk of DVT and of PVT by about half, again irrespective of the type of surgery, but too few studies had reported PE to provide reliable estimates of effect on this outcome. Dextran appeared to be less effective at preventing DVT than the heparin regimens studied. Dextran was associated with an increased risk of bleeding, but too few bleeds had occurred for the size of this excess risk to be estimated reliably.Compared with general anaesthesia, regional anaesthesia reduced the risk of DVT by about half, and this benefit appeared similar in each of the surgical settings studied. Regional anaesthesia was associated with less major bleeding than general anaesthesia.ConclusionIn the absence of a clear contraindication (such as severe peripheral arterial disease), patients undergoing a surgical procedure would be expected to derive net benefit from a mechanical compression method of thromboprophylaxis (such as graduated compression stockings), irrespective of their absolute risk of venous thromboembolism. Patients who are considered to be at particularly high risk of venous thromboembolism may also benefit from a pharmacological thromboprophylactic agent, but since oral anticoagulant and dextran regimens appear less effective at preventing DVT than standard low-dose unfractionated heparin or low molecular weight heparin regimens, they may be less suitable for patients at high risk of venous thromboembolism, even though they are associated with less bleeding. Whenever feasible, the use of regional anaesthesia as an alternative to general anaesthesia may also provide additional protection against venous thromboembolism. There is little information on the prevention of venous thromboembolism among high-risk medical patients (such as those with stroke), so further randomised trials in this area would be helpful
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