The abnormal metabolic state that accompanies diabetes renders arteries susceptible to atherosclerosis, being capable of altering the functional properties of multiple cell types, including endothelium and platelets. In particular, an altered platelet metabolism and changes in intraplatelet signaling pathways may contribute to the pathogenesis of atherothrombotic complications of diabetes. A variety of mechanisms may be responsible for enhanced platelet aggregation. Among them, hyperglycemia may represent a causal factor for in vivo platelet activation, and may be responsible for nonenzymatic glycation of platelet glycoproteins, causing changes in their structure and conformation, as well as alterations of membrane lipid dynamics. Furthermore, hyperglycemia-induced oxidative stress is responsible for enhanced peroxidation of arachidonic acid to form biologically active isoprostanes, which represents an important biochemical link between impaired glycemic control and persistent platelet activation. Finally, increased oxidative stress is responsible for activation of transcription factors and expression of redox-sensitive genes leading to a phenotypic switch of endothelium toward an adhesive, prothrombotic condition, initial platelet activation, adhesion and subsequent platelet aggregate formation. All this evidence is strengthened by the results of clinical trials documenting the beneficial effects of metabolic control on platelet function, and by the finding that aspirin treatment may even be more beneficial in diabetic than in high-risk non-diabetic patients. Attention to appropriate medical management of diabetic patients will have great impact on long-term outcome in this high-risk population. © 2004 International Society on Thrombosis and Haemostasis
Patients with cirrhosis can have abnormalities in laboratory tests reflecting changes in primary haemostasis, including bleeding time, platelet function tests, markers of platelet activation, and platelet count. Such changes have been considered particularly relevant in the bleeding complications that occur in cirrhosis. However, several studies have shown that routine diagnostic tests, such as platelet count, bleeding time, PFA-100, thromboelastography are not clinically useful to stratify bleeding risk in patients with cirrhosis. Moreover, treatments used to increase platelet count or to modulate platelet function could potentially do harm. Consequently the optimal management of bleeding complications is still a matter of discussion. Moreover, in the last two decades there has been an increased recognition that not only bleeding but also thrombosis complicates the clinical course of cirrhosis. Thus, we performed a literature search looking at publications studying both qualitative and quantitative aspects of platelet function to verify which primary haemostasis defects occur in cirrhosis. In addition, we evaluated the contribution of qualitative and quantitative aspects of platelet function to the clinical outcome in cirrhosis and their therapeutic management according to the data available in the literature. From the detailed analysis of the literature, it appears clear that primary haemostasis may not be defective in cirrhosis, and a low platelet count should not necessarily be considered as an automatic index of an increased risk of bleeding. Conversely, caution should be observed in patients with severe thrombocytopenia where its correction is advised if bleeding occurs and before invasive diagnostic and therapeutic procedures.
Eveningness may impact general health, either physical or mental, sleep, school results and achievements, especially in younger age and in women. The role of family support is crucial, and parents should be deeply informed that abuse of technological devices during night hours may lead to the immature adjustment function of children's endogenous circadian pacemakers.
Oxidative stress has been suggested as a potential mechanism in the pathogenesis of chronic obstructive pulmonary disease (COPD). It has been difficult to address this hypothesis because of the limitations of conventional indices of lipid peroxidation in vivo. F2-isoprostanes (iPs) are prostaglandin isomers formed by free radical dependent peroxidation of arachidonic acid. Urinary iPF2alpha-III is a relatively abundant iPs produced in humans. In the present study, we investigated whether COPD is associated with enhanced oxidative stress by measuring urinary levels of this compound. Urinary excretion of iPF2alpha-III was determined in 38 patients with COPD and 30 sex- and age-matched healthy control subjects. Levels of iPF2alpha-III were significantly higher in patients with COPD (median, 84 pmol/ mmol creatinine; range, 38 to 321) than in healthy controls (median, 35.5 pmol/mmol creatinine; range, 15 to 65) (p < 0.0001). This elevation was independent of age, sex, smoking history, or duration of the disease. An inverse relationship was observed with the level of PaO2 (r = -0.38, p = 0. 019). Aspirin treatment failed to decrease urinary levels of iPF2alpha-III (102 +/- 8 versus 99.2 +/- 7.3 pmol/ mmol creatinine), whereas 11-dehydro TxB2 was significantly reduced (695 +/- 74 versus 95 +/- 10 pmol/mmol creatinine) (p < 0.0001). Elevated levels of iPF2alpha-III (median, 125 pmol/mmol creatinine; range, 110 to 170) in five patients with COPD declined (median, 90 pmol/mmol creatinine; range, 70 to 110) (p < 0.001) as an acute exacerbation in their clinical condition resolved. Increased urinary iPF2alpha-III is consistent with the hypothesis that oxidative stress occurs in COPD. This provides a basis for dose finding and evaluation of antioxidant therapy in the treatment of this disease.
SummaryOral anticoagulation is pivotal in the management of thromboembolic risk in non-valvular atrial fibrillation (NVAF) patients. Effective anticoagulation is important to avoid major adverse events and medication adherence is central to achieve good anticoagulation control. Non-vitamin K antagonist oral anticoagulants (NOACs) are as effective and safe as vitamin K antagonist (VKAs) in NVAF patients. Due to the absence of routine anticoagulation monitoring with NOACs treatment, concerns have been raised about patient's adherence to NOACs and real-life data demonstrates variability in adherence and persistence. A multi-level approach, including patients' preferences, factors determining physicians' prescribing habits and healthcare system infrastructure and support, is warranted to improve initiation and adherence of anticoagulants. Adherence to NOACs is paramount to achieve a clinical benefit. Implementation of educational programs and easyto-use tools to identify patients most likely to be non-adherent to NOACs, are central issues in improving the quality of NVAF anticoagulation management.
Background-Statins exert an antithrombotic effect in patients at risk of or with acute thrombosis, but no study has investigated whether this effect is immediate and whether there is an underline mechanism. Methods and Results-Patients with hypercholesterolemia were randomly allocated to a Mediterranean diet with low cholesterol intake (Ͻ300 mg/d; nϭ15) or atorvastatin (40 mg/d; nϭ15). Oxidative stress, as assessed by serum Nox2 and urinary isoprostanes, and platelet activation, as assessed by platelet recruitment, platelet isoprostanes, and thromboxane A 2 , platelet Nox2, Rac1, p47
Objective-The inhibition of oxidative stress is among the most relevant pleiotropic effects of statins. The mechanism by which statins exert their antioxidant effect in vivo is still undefined. NADPH oxidase is among the most important sources of reactive oxygen species involved in atherosclerotic disease. Methods/Results-We developed an ELISA to evaluate serum levels of soluble-gp91 phox , the catalytic core of phagocyte NADPH oxidase. In a cross-sectional study performed in 30 hypercholesterolemic patients and in 20 controls, serum soluble-gp91 phox and urinary isoprostane, a marker of oxidative stress, were measured. The 2 variables were also measured in hypercholesterolemic patients, randomized to diet (nϭ15), or diet plus atorvastatin (10 mg daily, nϭ15) and followed for 30 days. Compared to controls, hypercholesterolemic patients had higher and significantly correlated (Rϭ0.71; PϽ0.001) serum soluble-gp91 phox (PϽ0.001) and urinary isoprostanes (PϽ0.001). After follow-up, the statin-allocated group showed a significant reduction of soluble-gp91 phox (Ϫ33%, PϽ0.01), that paralleled that of isoprostanes (Ϫ37%, PϽ0.01) and cholesterol (Ϫ25%, PϽ0.01). The diet-allocated group showed only a weak reduction of cholesterol. Key Words: gp91 phox Ⅲ oxidative stress Ⅲ hypercholesterolemia Ⅲ NADPH oxidase Ⅲ statins P rimary and secondary prevention trials with statins clearly demonstrated that this drug category is able to reduce cardiovascular events. 1,2 Even if the principal mechanism of action of statins is to lower cholesterol, other effects, the so-called pleiotropic effects, have been considered as adjunctive properties potentially accounting for the antiatherosclerotic effect of statins. 3 Inhibition of oxidative stress may be considered an intriguing pleiotropic effect in view of the fact that oxidative stress is thought to be a key event in the initiation and progression of atherosclerotic disease. 4 Reduction of several markers of oxidative stress including isoprostanes, 8-hydroxydeoxyguanosine (8-OHdG), and nitrotyrosine have been observed after statin treatment but the underlying mechanism is still unclear. [5][6][7][8][9] In a pilot study performed in patients with chronic granulomatous disease (X-CGD), a very rare life-threatening disease secondary to hereditary deficiency of gp91 phox (the catalytic subunit of phagocyte NADPH oxidase), we found a significant reduction of urinary isoprostanes. 10 Also, in children with hypercholesterolemia, we observed a significant correlation between platelet gp91 phox expression and urinary isoprostanes. 11 These previous observations suggest a role for the phagocyte NADPH oxidase, one of the most important cellular producers of superoxide anion (O 2 . ), 12 in the formation of this marker of oxidative stress. Because previous studies provided in vitro evidence that statins inhibit the expression and activation of NADPH oxidase, 6,13 we sought to analyze whether this occurs in vivo and ultimately contributes to the reduction of oxidative stress. Thus, we developed ...
LPS may be responsible for platelet activation and potentially contributes to thrombotic complications occurring in cirrhosis. (Hepatology 2017;65:571-581).
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