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The role of ATP-binding cassette (ABC) transporters in conferring insecticide resistance has received much attention recently. Here we identify ABC transporters differentially expressed in insecticide-resistant populations of the malaria vector, Anopheles gambiae. Although we found little evidence that the orthologues of the multidrug resistance proteins described in other species are associated with resistance in An. gambiae we did identify a subset of ABC proteins consistently differentially expressed in pyrethroid-resistant populations from across Africa. We present information on the phylogenetic relationship, primary sites of expression and potential role of ABC transporters in mediating the mosquito's response to insecticides. Furthermore we demonstrate that a paralogous group of eight ABCG transporters, clustered on chromosome 3R, are highly enriched in the legs of An. gambiae mosquitoes, consistent with a proposed role for this ABC subfamily in transport of lipids to the outer surface of the cuticle. Finally, antibodies raised against one of the most highly expressed ABC transporters in adult females, ABCG7 (AGAP009850), localized this transporter to the pericardial cells. These data will help prioritize members of this gene family for further localization and functional validation studies to identify the in vivo function of these transporters in the mosquito and determine whether elevated expression of members of this family contribute to insecticide resistance. [ABSTRACT FROM AUTHOR]

Objectives The aim of the study was to investigate the in vivo effect of abacavir ( ABC) on platelet oxidative stress. Methods We performed a randomized pilot study including 39 HIV-1-infected patients, 17 on zidovudine/lamivudine ( ZDV/3 TC) and 22 on tenofovir/emtricitabine ( TDF/ FTC). Ten patients on ZDV/3 TC and eight patients on TDF/ FTC were randomly allocated to switching the nucleoside backbone to ABC/3 TC. At baseline and after 6 months, platelet oxidative stress was assessed by platelet NADPH oxidase 2 (NOX2)-derived peptide (sNOX2-dp), a marker of NOX2 activation, and platelet prostaglandin F2α (8-iso-PGF2α). Platelet activation was measured by soluble CD40L (sCD40L). Results At baseline, no differences between ZDV/3TC or TDF/FTC recipients were found. After 6 months, patients switching from ZDV/3TC showed a decrease of sNOX2-dp (from 20.9±5.7 to 12.5±3.8 pg/ml, p=0.002) and 8-iso-PGF2α (from 154.3±41.9 to 122.9±28.0 pmol/l, p=0.025). No effects on platelet oxidative stress biomarkers were observed in subjects from TDF/FTC, who showed a significant increase in blood glucose (p=0.043) and total cholesterol (p=0.027). ABC showed no effect on sCD40L levels in both groups. Conclusions ABC reduced platelet sNOX2-dp and 8-iso-PGF2α in HIV-1 subjects switching from ZDV/3TC but not in those from TDF/FTC after 6 months. No changes in platelet activation were found in both groups. [ABSTRACT FROM AUTHOR]

Background: The surgical/anesthesia trauma is associated with an increased production of reactive oxygen species (ROS). This enhanced oxidative stress leads to cell damage resulting in various complications such as sepsis, myocardial injury and increased mortality. The aim of this study was to investigate the role of antioxidant treatment with l-carnitine in oxidative stress and platelet activation in patients undergoing major abdominal surgery. Methods: Forty patients scheduled for abdominal surgery were randomly allocated to l-carnitine, administered with a rapid infusion (0.05 g/kg) diluted in 250 ml of saline solution, vs. placebo treatment just before the surgical intervention. At baseline and after treatment, oxidative stress was evaluated by detection of circulating levels of soluble NOX2-derived peptide (sNOX2-dp), a marker of NADPH oxidase activation, and by analyzing platelet ROS formation. Platelet activation was studied by dosing sCD40L. Results: We observed an increase of soluble sNOX2-dp, sCD40L and ROS production in the placebo group compared with the baseline after the surgical intervention. Conversely, in the l-carnitine-treated group, sNOX2-dp, sCD40L and ROS production did not significantly differ from the baseline. A linear correlation analysis showed that Δ of ROS correlated with Δ of sNOX2 ( Rs=0.817; P<0.001) and Δ of sCD40L ( Rs=0.780; P<0.001). Multiple linear regression analysis showed that the only independent predictive variable associated with Δ of ROS was Δ of serum NOX2 levels (SE=0.05; standardized coefficient β=1.075; P<0.001). Conclusion: Our findings suggest that l-carnitine could be helpful in modulating oxidative stress and platelet activation during major abdominal surgery-dependent oxidative damage. [ABSTRACT FROM AUTHOR]

Background Rapid virological response (RVR) is the best predictor of sustained response to standard HCV treatment. Aim To evaluate predictive factors of RVR. Methods Sixty-five patients (mean age 52.6 ± 13.8; 37 genotype-1, and 28 genotypes-2/3) were consecutively treated with pegIFN-alpha2a or 2b once weekly plus daily ribavirin based on body weight for 24 or 48 weeks, according to genotype. RVR was defined as undetectable HCV-RNA at week 4. Results Twenty-seven percent of patients achieved RVR in genotypes 1 and 60.7% in genotypes 2/3 ( P < 0.01). Rapid responders had higher mean serum baseline total and LDL-cholesterol levels ( P < 0.01). RVR was 20.0% in the bottom tertile of total cholesterol and 63.6% in the top tertile ( P < 0.01). HCV-RNA levels at week 4 were positively correlated with baseline serum insulin ( P < 0.01), HOMA-IR ( P < 0.01), body mass index ( P < 0.05) and number of components of metabolic syndrome ( P < 0.01) and negatively correlated with cholesterol levels ( P < 0.05). At multivariate analysis, age, LDL-cholesterol, HCV genotype and serum 8-iso-PGF2alpha, a marker of oxidative stress, were independent predictors of RVR. Conclusions Our prospective study supports a role of low serum total and LDL-cholesterol and of oxidative stress as positive independent predictive factors of poor RVR in HCV patients. [ABSTRACT FROM AUTHOR]

Background: Sleep disturbances are common during aging. Old mice show altered sleep structure, with changes in both slow and fast electro‐corticographic (ECG) activity, and less transitions between sleep and wake stages, as compared to young animals. Insulin‐like growth factor I (IGF‐I), that is involved in hormonal changes during aging, was previously shown to increase ECG patterns in young mice and monkeys. More recently, we observed that IGF‐I shapes sleep architecture through modulation of the activity of mouse orexin neurons in the lateral hypothalamus (LH). Method: We now report that both stimulation of ECG patterns and activation of orexin neurons by systemic IGF‐I were abrogated in old mice. Further, activation of orthodromically stimulated LH neurons by either systemic or local IGF‐I in young mice was absent in old mice. Result: As orexin neurons of old mice show markedly increased IGF‐I receptor (IGF‐IR) levels, suggesting loss of sensitivity to IGF‐I, we treated them with AIK3a305, a novel IGF‐IR sensitizer, and observed restored responses to IGF‐I and rejuvenation of ECG patterns. Conclusion: Thus, disturbed sleep structure in aging mice may be related to IGF‐I resistance in orexin neurons, reflecting a broader loss of IGF‐I activity in the aged mouse brain. [ABSTRACT FROM AUTHOR]

Oxidative stress-mediated LDL modification has a key role in initiation of the atherosclerotic process. Platelets produce reactive oxidant species (ROS) upon stimulation with agonist, but it is uncertain whether they are able to oxidatively modify LDL. Human platelets taken from healthy subjects were incubated with LDL, then stimulated with collagen. Compared with unstimulated platelets, collagen-stimulated platelets induced LDL modification as shown by enhanced conjugated dienes and lysophosphatidylcholine formation, electrophoretic mobility, Apo B-100 degradation, and monocyte LDL uptake. Activated platelets also induced a marked reduction of vitamin E contained in LDL. A significant inhibition of LDL oxidation was observed in platelets treated with arachidonyl trifluomethyl ketone (AACOCF3), an inhibitor of phospolipase A2. The experiments reported above were also conducted in patients with hereditary deficiency of gp91phox, the central core of NADPH oxidase, and in patients with hypercholesterolemia. Platelets from gp91 phox-deficient patients produced a small amount of ROS and weakly modified LDL. Conversely, platelets from hypercholesterolemic patients showed enhanced ROS formation and oxidized LDL more than platelets from healthy subjects. This study provides evidence that platelets modify LDL via NADPH oxidase-mediated oxidative stress, a phenomenon that could be dependent on arachidonic acid activation. This finding suggests a role for platelets in favoring LDL accumulation within atherosclerotic plaque. [ABSTRACT FROM AUTHOR]

Several studies demonstrated an inverse association between polyphenol intake and cardiovascular events. Platelet recruitment is an important phase of platelet activation at the site of vascular injury, but has never been investigated whether polyphenols influence platelet recruitment. The aim of the study was analyze in vitro whether two polyphenols, quercetin and catechin, were able to affect platelet recruitment. Platelet recruitment was reduced by NO donors and by NADPH oxidase inhibitors and was enhanced by L-NAME, an inhibitor of NO synthase. Quercetin and catechin, but not single polyphenol, significantly inhibited platelet recruitment in a concentration-dependent fashion. The formation of superoxide anion was significantly inhibited in platelets incubated with quercetin and catechin but was unaffected by a single polyphenol. Incubation of platelets with quercetin and catechin resulted in inhibition of PKC and NADPH oxidase activation. Treatment of platelets with quercetin and catechin resulted in an increase of NO and also down-regulated the expression of GpIIb/IIIa glycoprotein. This study shows that the polyphenols quercetin and catechin synergistically act in reducing platelet recruitment via inhibition of PKC-dependent NADPH oxidase activation. This effect, resulting in NO-mediated platelet glycoprotein GpIIb/IIIa down-regulation, could provide a novel mechanism through which polyphenols reduce cardiovascular disease. [ABSTRACT FROM AUTHOR]

Background: Aging and dementia are related to sleep and circadian disturbances. These disturbances are attributed to neurodegeneration of brain networks involved in sleep. On the other hand, increasing evidence supports the notion that Alzheimer's disease (AD), a condition that presents heterogeneous pathological disturbances, including sleep regulation, is also associated with perturbed metabolic function affecting insulin‐like growth factor I (IGF‐I). Moreover, metabolic alterations are commonly associated with sleep disturbances. In this work we took advantage of a very specific group of cells ‐ orexinergic neurons ‐ that are involved in sleep/circadian regulation, to study how IGF‐I may modulate their activity, as well as its role in sleep regulation through aging. Method: We use electrophysiology, optogenetic, and immunofluorescence techniques. Transgenic mice without IGF‐I Receptor in orexinergic neurons (Firoc mice) and C57 animals (young vs old mice) were used. Result: We found reduce C‐fos expression in orexin neurons after IGF‐I injection (ip). As well as diminish response to local and systemic IGF‐I in electrophysiology experiments in Firoc mice, determined by the responses of PeF neurons to locus coeruleus (LC) stimulation. We also found perturbations in sleep and lower levels of orexin in Firoc hypothalamus. To confirm the participation of IGF‐I modulation of orexinergic neurons, we optogenetically identify orexin neurons using a mouse expressing channelrhodopsin (ChR) specifically in these cells and inject IGF‐I locally. These results suggest that IGF‐I modulates orexinergic function. Then, we use elderly C57 mice to check if orexinergic neurons respond normally to IGF‐I. We found a reduce orexinergic neurons response to IGF‐I in electrophysiology experiments. Conclusion: These initial results reinforce recent observations that IGF‐I act as a peripheral circadian marker and modulates sleep through orexin neurons, and suggests that sleep disturbances in the elderly may be related to altered brain IGF‐I input to orexin neurons. [ABSTRACT FROM AUTHOR]

Background and Purpose: Corticosteroids are often prescribed to community-acquired pneumonia (CAP) patients, but the relationship with major cardiovascular events (MACEs) is unclear., Experimental Approach: 541 CAP patients were recruited (334 males, mean age 71.9 ± 16.2 years). High-sensitivity troponin T (hs-cTnT) was measured at admission, during the hospital stay and at discharge. MACE occurrence was registered during a long-term follow-up., Key Results: Overall, 318 patients (59%) showed hs-cTnT elevation >99th percentile (>0.014 μg/L). Age, heart failure and the increasing quintiles of hs-cTnT (hazard ratio [HR] 2.16, 95% confidence interval [CI] 1.82-2.58, P < .001) predicted MACEs. Among patients with hs-cTnT >0.014 μg/L at admission, 102 patients (31%) were on corticosteroids and showed lower hs-cTnT increase (P = .021), (NADPH) oxidase-2 (Nox2) activation (P = .005) and incidence of MACEs than untreated ones (HR 0.64, 95% CI 0.41-0.97, P = .038); no effect of corticosteroids on MACEs was observed in CAP patients with normal troponin. In vitro study showed that glucocorticoids have an antioxidant effect via downregulation of Nox2 activity., Conclusion and Implications: The study provides evidence that corticosteroid use is associated with lower increase of hs-cTnT and incidence of MACEs in CAP patients., (© 2021 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Aims: To investigate the decline of estimated glomerular filtration rate (eGFR) in patients with atrial fibrillation (AF) treated with vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs)., Methods: Multicentre prospective cohort study including 1667 patients with nonvalvular AF. The eGFR was assessed by the CKD-EPI formula at baseline and during follow-up. The primary endpoint of the study was the median annual decline of eGFR according to VKA (n = 743) or NOAC (n = 924) use. As secondary endpoints, we analysed the transition to eGFR <50 mL/min/1.73 m 2 and the eGFR class worsening., Results: Median age was 73.7 ± 9.1 years and 43.3% were women. VKA-treated patients showed an eGFR decline of -2.11 (interquartile range [IQR] -5.68/-0.62), which was -0.27 (IQR -9.00/4.54, P < 0.001 vs VKAs), -1.21 (IQR -9.98/4.02, P = 0.004 vs VKAs) and -1.32 (IQR -8.70/3.99, P = 0.003 vs VKAs) in patients on dabigatran, rivaroxaban and apixaban, respectively. Transition to eGFR <50 mL/min/1.73 m 2 was lower in dabigatran- and apixaban-treated patients: odds ratio (OR) 0.492, 95% confidence interval (CI) 0.298-0.813, P = 0.006 and OR 0.449, 95% CI 0.276-0.728, P = 0.001, respectively. A lower rate of eGFR class worsening was found in all groups of NOACs compared to VKAs. No difference between full and reduced dose of NOAC was found. Subgroup analysis showed that the association between NOAC and eGFR changes was markedly reduced in diabetic patients., Conclusion: Patients prescribed NOACs showed a lower decline of renal function compared to those prescribed VKAs. This effect was partially lost in patients with diabetes., (© 2020 The British Pharmacological Society.)

Quality of warfarin therapy in patients with a mechanical prosthetic heart valve (MPHV) has been barely investigated. We analysed determinants of low time in the therapeutic range (TiTR <60%) in 2111 patients with MPHVs from the nationwide PLECTRUM study by the Italian Federation of Anticoagulation Clinics. Overall, 48·5% of patients had a TiTR of < 60%. At logistic regression analysis, arterial hypertension (odds ratio [OR] 1·502, P < 0·001), diabetes (OR 1·732, P < 0·001), heart failure (OR 1·484, P = 0·004), mitral site (vs. aortic) (OR 1·399, P = 0·006), international normalised ratio (INR) ranges of 2·5-3·5 (OR 2·575, P < 0·001) and 3·0-4·0 (OR 8·215, P < 0·001) associated with TiTR < 60%. TiTR is substantially suboptimal in MPHV patients, particularly in higher INR ranges., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)

Background Thrombocytopenia is associated with increased mortality in the general population, but few data exist in patients with atrial fibrillation (AF) taking oral anticoagulants. We investigated factor determinants of thrombocytopenia in a large cohort of patients affected by AF and its association with total mortality. Methods and Results Multicenter prospective cohort study, including 5215 patients with AF from the START (Survey on Anticoagulated Patients Register) registry, 3877 (74.3%) and 1338 (25.7%) on vitamin K or non-vitamin K antagonist oral anticoagulants, respectively. Thrombocytopenia was defined by a platelet count <150×10 9 /L. Determinants of thrombocytopenia were investigated, and all-cause mortality was the primary survival end point of the study. Thrombocytopenia was present in 592 patients (11.4%). At multivariable logistic regression analysis, chronic kidney disease (odds ratio [OR], 1.257; P =0.030), active cancer (OR, 2.065; P =0.001), liver cirrhosis (OR, 7.635; P <0.001), and the use of diuretics (OR, 1.234; P =0.046) were positively associated with thrombocytopenia, whereas female sex (OR, 0.387; P <0.001) and the use of calcium channel blockers (OR, 0.787; P =0.032) were negatively associated. During a median follow-up of 19.2 months (9942 patient-years), 391 deaths occurred (rate, 3.93%/year). Mortality rate increased from 3.8%/year to 9.9%/year in patients with normal platelet count and in those with moderate-severe thrombocytopenia, respectively (log-rank test, P =0.009). The association between moderate-severe thrombocytopenia and mortality persisted after adjustment for CHA 2 DS 2 VASc score (hazard ratio, 2.431; 95% CI, 1.254-4.713; P =0.009), but not in the fully adjusted multivariable Cox regression analysis model. Conclusions Thrombocytopenia is common in patients with AF. Despite an increased incidence of mortality, thrombocytopenia was not associated with mortality at multivariable analysis. Thrombocytopenia may reflect the presence of comorbidities associated with poor survival in AF.

Background Little clinical research on new-generation heat-not-burn cigarettes ( HNBC ) in comparison with electronic vaping cigarettes ( EVC ) and traditional tobacco combustion cigarettes ( TC ) has been reported. We aimed to appraise the acute effects of single use of HNBC , EVC, and TC in healthy smokers. Methods and Results This was an independent, cross-over, randomized trial in 20 TC smokers, with allocation to different cycles of HNBC , EVC , and TC . All participants used all types of products, with an intercycle washout of 1 week. End points were oxidative stress, antioxidant reserve, platelet activation, flow-mediated dilation, blood pressure, and satisfaction scores. Single use of any product led to an adverse impact on oxidative stress, antioxidant reserve, platelet function, flow-mediated dilation, and blood pressure. HNBC had less impact than EVC and TC on soluble Nox2-derived peptide (respectively, P=0.004 and 0.001), 8-iso-prostaglandin F2α- III ( P=0.004 and <0.001), and vitamin E ( P=0.018 and 0.044). HNBC and EVC were equally less impactful than TCs on flow-mediated dilation ( P=0.872 for HNBC versus EVC ), H 2 O 2 ( P=0.522), H 2 O 2 breakdown activity ( P=0.091), soluble CD 40 ligand ( P=0.849), and soluble P-selectin ( P=0.821). The effect of HNBC and, to a lesser extent EVC , on blood pressure was less evident than that of TC , whereas HNBC appeared more satisfying than EVC (all P<0.05). Conclusions Acute effects of HNBC , EVC, and TC are different on several oxidative stress, antioxidant reserve, platelet function, cardiovascular, and satisfaction dimensions, with TCs showing the most detrimental changes in clinically relevant features. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 03301129.

The prevalence and incidence of atrial fibrillation/flutter (AF/AFL) in patients with human immunodeficiency virus type-1 (HIV-1) infection have been poorly investigated. We performed a systematic review using PubMed and Cochrane Database of Systematic Reviews, and screening of references, searching for clinical studies reporting on the association between HIV-1 infection and AF/AFL. We also summarized the main interactions of antiretroviral agents with antithrombotic and antiarrhythmic drugs. We found a prevalence of AF/AFL ranging from 2.0% to 5.13% in patients with HIV-1, with an incidence rate of 3.6/1000 person-years. Low CD4+ count (<200-250 cells ml -1 ) and high viral load were predictors of AF/AFL. Regarding drugs interactions, nucleoside reverse transcriptase inhibitors, integrase inhibitor and maraviroc have the lowest interactions with oral anticoagulants. Among anticoagulants, dabigatran presents the most favourable profile. Most of antiarrhythmic drugs interact with protease inhibitors, with beta blockers and diltiazem having fewer interactions. The few studies available suggest a non-negligible prevalence of AF/AFL in patients with HIV-1 infection. Awareness of potential interactions with anticoagulation and antiarrhythmic drugs is needed to offer optimal management in this population., (© 2018 The British Pharmacological Society.)

Background Digoxin use was shown to be associated with an increased risk of cardiovascular events in atrial fibrillation ( AF ). We hypothesized that digoxin may affect cardiovascular risk by increasing platelet activation. Methods and Results Post hoc analysis of a prospective study of anticoagulated patients with AF . Patients were divided into 2 groups balanced for age, sex, and cardiovascular risk factors: digoxin users (n=132) and nonusers (n=388). Urinary excretion of 11-dehydro-thromboxane B 2 (TxB 2 ), a marker of platelet activation, and serum digoxin concentration ( SDC ) were measured. In vitro experiments were performed on platelets from healthy subjects and AF patients, which were incubated with scalar doses of digoxin (0.6-2.4 ng/mL) with or without prestimulation with a sub-threshold of collagen. Median 11-dehydro-TxB 2 was 105.0 ( interquartile range, 60.0-190.0) ng/mg creatinine, and median SDC was 0.65 ( interquartile range, 0.40-1.00) ng/mL. Urinary 11-dehydro-TxB 2 and SDC were correlated ( r s =0.350, P<0.001). Patients in the upper tertile of SDC showed higher 11-dehydro-TxB 2 compared with non-digoxin users ( P=0.019). In vitro study showed an increased basal platelet activation in patients with AF compared with healthy subjects . Digoxin (2.4 ng/mL) induced calcium mobilization, PAC -1 (procaspase-activating compound 1) and platelet aggregation in AF patients but not in healthy subjects . After pretreatment with a sub-threshold of collagen, digoxin dose-dependent induced calcium mobilization, arachidonic acid release, TxB 2 biosynthesis, PAC -1 and soluble platelet selectin expression, and platelet aggregation, which were inhibited by antibody against digoxin. Conclusions We found a significant in vivo correlation between SDC and platelet activation. Supratherapeutic SDC increased in vitro platelet aggregation via calcium-related phospholipase A 2 phosphorylation. Our findings may have clinical implications for AF patients treated with digoxin.

Background: Gut microbiota is emerging as a novel risk factor for atherothrombosis, but the predictive role of gut-derived lipopolysaccharide (LPS) is unknown. We analyzed (1) the association between LPS and major adverse cardiovascular events (MACE) in atrial fibrillation (AF) and (2) its relationship with adherence to a Mediterranean diet (Med-diet)., Methods and Results: This was a prospective single-center study including 912 AF patients treated with vitamin K antagonists (3716 patient-years). The primary end point was a composite of MACE. Baseline serum LPS, adherence to Med-diet (n=704), and urinary excretion of 11-dehydro-thromboxane B 2 (TxB 2 , n=852) were investigated. Mean age was 73.5 years; 42.9% were women. A total of 187 MACE (5.0% per year) occurred: 54, 59, and 74 in the first, second, and third tertile of LPS, respectively (log-rank test P =0.004). Log-LPS (hazard ratio 1.194, P =0.009), age (hazard ratio 1.083, P <0.001), and previous cerebrovascular (hazard ratio 1.634, P =0.004) and cardiac events (hazard ratio 1.822, P <0.001) were predictors of MACE. In the whole cohort, AF (versus sinus rhythm) (β 0.087, P =0.014) and low-density lipoprotein cholesterol (β 0.069, P =0.049) were associated with circulating LPS. Furthermore, Med-diet score (β -0.137, P <0.001) was predictive of log-LPS, with fruits (β -0.083, P =0.030) and legumes (β -0.120, P =0.002) negatively associated with log-LPS levels. Log-LPS and log-TxB 2 were highly correlated (r=0.598, P <0.001). Log-LPS (β 0.574, P <0.001) and Med-diet score (β -0.218, P <0.001) were significantly associated with baseline urinary excretion of TxB 2 ., Conclusions: In this cohort of AF patients, LPS levels were predictive of MACE and negatively affected by high adherence to Med-diet. LPS may contribute to MACE incidence in AF by increasing platelet activation., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Experimental studies demonstrated that glutathione peroxidase 3 (GPx3), an antioxidant enzyme that catabolizes hydrogen peroxide, protects against thrombosis. Little is known about its role in cardiovascular disease., Methods and Results: A prospective cohort study was conducted in 909 atrial fibrillation patients. Serum activities of GPx3, superoxide dismutase (SOD), and catalase were measured at baseline to assess the risk of cardiovascular events during a mean follow-up of 43.4 months (3291 person-years). Serum Nox2 and urinary excretion of 11-deydro-thromboxane B2 were also measured. During follow-up 160 cardiovascular events occurred (4.9%/year). Significantly lower values of GPx3 (P<0.001) and SOD (P=0.037) were detected in patients with, compared to those without, cardiovascular events. A lower survival rate was observed in patients with GPx3 (P<0.001) and SOD (P=0.010) activities below the median, as compared to those above. In a fully adjusted Cox regression model, GPx3 was the only antioxidant enzyme predictor of cardiovascular events (hazard ratio 0.647, 95% confidence interval 0.524-0.798, P<0.001). GPx3 was inversely associated with urinary 11-dehydro-thromboxane B2 (B -0.337, P<0.001) and serum Nox2 (B: -0.423, P<0.001). GPx3 activity progressively decreased with decades of age (P<0.001), with a progressive reduction in people aged ≥70 years., Conclusions: This study provides evidence that a low antioxidant status, as depicted by reduced levels of GPx3, increases the risk of cardiovascular events in patients with atrial fibrillation. The age-related decline of GPx3 may represent a mechanism for the enhanced cardiovascular risk in the elderly population., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: A growing body of evidence suggests that atrial fibrillation (AF) is associated with myocardial infarction (MI). However, incidence and management of MI in AF is still undefined., Methods and Results: We searched MEDLINE via PubMed and Cochrane database between 1965 and 2015. All observational clinical studies and interventional trials reporting 1-year incidence of MI in AF were included. We also discussed pathophysiological mechanisms, predictors, and therapeutic approaches to reduce the risk of MI in AF. Twenty-one observational studies and 10 clinical trials were included. The annual rate of MI in observational studies including AF patients ranged from 0.4% to 2.5%. Higher rates of MI were reported in AF patients with stable coronary artery disease (11.5%/year), vascular disease (4.47%/year), heart failure (2.9%/year), and in those undergoing coronary artery interventions (6.3%/year). However, lower annual rates have been described in AF patients from Eastern countries (0.2-0.3%/year), and in those enrolled in clinical trials (from 0.4 to 1.3%/year)., Conclusions: AF patients had a significant residual risk of MI despite anticoagulant treatment. Coexistence of atherosclerotic risk factors and platelet activation account for the increased risk of MI in AF. Identification of high-risk AF patients is a needed first step to develop cost-effective approaches for prevention. A new score, the 2MACE score, has been recently developed to stratify MI risk in AF, and may help not only in allocating resources to high-risk groups, but also in design of studies examining novel therapies for prevention of MI in AF., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: NOX-2, the catalytic subunit of NADPH oxidase, has a key role in the formation of reactive oxidant species and is implicated in impairing flow-mediated dilation (FMD). Dark chocolate exerts artery dilatation via down-regulating NOX2-mediated oxidative stress. The aim of this study was to investigate whether dark chocolate improves walking autonomy in peripheral artery disease (PAD) patients via an oxidative stress-mediated mechanism., Methods and Results: FMD, serum levels of isoprostanes, nitrite/nitrate (NOx) and sNOX2-dp, a marker of blood NOX2 activity, maximal walking distance (MWD) and maximal walking time (MWT) were studied in 20 PAD patients (14 males and 6 females, mean age: 69±9 years) randomly allocated to 40 g of dark chocolate (>85% cocoa) or 40 g of milk chocolate (≤35% cocoa) in a single blind, cross-over design. The above variables were assessed at baseline and 2 hours after chocolate ingestion. Dark chocolate intake significantly increased MWD (+11%; P<0.001), MWT (+15%; P<0.001), serum NOx (+57%; P<0.001) and decreased serum isoprostanes (-23%; P=0.01) and sNOX2-dp (-37%; P<0.001); no changes of the above variables were observed after milk chocolate intake. Serum epicatechin and its methylated metabolite significantly increased only after dark chocolate ingestion. Multiple linear regression analysis showed that Δ of MWD was independently associated with Δ of MWT (P<0.001) and Δ of NOx (P=0.018). In vitro study demonstrated that HUVEC incubated with a mixture of polyphenols significantly increased nitric oxide (P<0.001) and decreased E-selectin (P<0.001) and VCAM1 (P<0.001)., Conclusion: In PAD patients dark but not milk chocolate acutely improves walking autonomy with a mechanism possibly related to an oxidative stress-mediated mechanism involving NOX2 regulation., Clinical Trial Registration Url: http://www.clinicaltrials.gov. Unique identifier: NCT01947712., (© 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: In vitro study showed that NADPH oxidase (NOx), the most important enzyme producing reactive oxygen species (ROS), plays a role in the process of platelet activation. However, it is unclear if changes in its activity affect platelet activation in vivo., Methods and Results: In vivo and ex vivo experiments assessing platelet activation were investigated in healthy subjects, obese patients, and subjects with different low rates of NOx2 activity, namely X-linked chronic granulomatous disease (X-CGD) patients and X-CGD carriers. We included 27 X-CGD patients, 31 women carriers of hereditary deficiency of NOx2, 31 obese women, and 62 healthy subjects matched for sex and age. Plasma levels of soluble sCD40 L (sCD40L) and soluble P (sP)-selectin, 2 markers of in vivo platelet activation, were reduced in X-CGD patients (sCD40L=-55%; sP-selectin=-51%, P<0.001) and in X-CGD carriers (sCD40L=-41%; sP-selectin=-57%, P<0.001) compared with respective controls. Conversely, obese women, who disclosed NOx2 upregulation, had significantly higher plasma levels of sCD40L (+47%, P<0.001) and sP-selectin (+70%, P<0.001) compared with controls. Ex vivo study showed platelet isoprostane downexpression and enhanced platelet NO generation in both X-CGD patients and X-CGD carriers compared with controls; opposite findings were observed in obese patients. Correlation analysis showed that platelet NOx2 regulation was directly associated with plasma levels of sCD40L (R=0.336, P<0.001) and sP-selectin (R=0.441; P<0.001)., Conclusions: The study provides the first evidence that in vivo platelet activation is significantly and directly associated with NOx2 activity. Platelet NOx2 may be a novel target for platelet activation inhibition., (© 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: Hemorrhagic risk assessment is a crucial issue in patients with nonvalvular atrial fibrillation (NVAF) who are receiving oral anticoagulant therapy (OAT). Our aim was to analyze the relationship between vitamin E, which possesses anticoagulant properties, and bleeding events in NVAF patients., Methods and Results: In this retrospective observational study we analyzed baseline serum cholesterol-adjusted vitamin E (vit E/chol) levels in 566 consecutive patients (59% males, mean age 73.6 years) receiving OAT followed up for a mean time of 22 months. Mean time in therapeutic INR range (TTR) was 64%. The overall incidence rate of any bleeding event was 9.2/100 person-years. Compared to patients who did not bleed, those who experienced bleeding events (n=92, 73 minor and 15 major bleedings and 4 cerebral hemorrhages according to International Society on Thrombosis and Haemostasis [ISTH] ) classification) showed a significant difference for history of coronary heart disease (P=0.039), HAS-BLED score (P=0.002), and vit E/chol levels (P<0.001). Higher vit E/chol serum levels were found in patients who bled compared to those who did not (5.27 ± 1.93 versus 4.48 ± 1.97 μmol/cholesterol; P<0.001), with a progressive increase from minor (5.16 ± 1.91 μmol/mmol cholesterol, P=0.006) to major bleedings (5.72 ± 2.0 μmol/mmol cholesterol, P=0.008). A Cox proportional hazard model demonstrated that serum vit E/chol quartiles (global P=0.0189) and HAS-BLED scores (P=0.005) predicted bleeding events., Conclusions: In a NVAF population being treated with warfarin, serum vitamin E predicted hemorrhagic events. Further study is necessary to see if the relationship between serum levels of vitamin E and bleeding is still maintained with the use of new anticoagulants.

Background: Urinary 8-iso-PGF2α, a marker of oxidative stress, is influenced by the activation of NOX2. It is unclear if platelets 8-iso-PGF2α contribute to urinary 8-iso-PGF2α., Methods and Results: In a cross-sectional study, platelet, urinary, and serum 8-iso-PGF2α were determined in subjects with downregulation (X-linked chronic granulomatous disease [X-CGD], n=25) and upregulation (type II diabetic patients [T2D], n=121) of NOX2 and 153 controls matched for sex and age. In diabetic patients (n=18), the above variables were repeated before and after 7 days treatment with 100 mg/day aspirin or 100 mg/day aspirin plus 40 mg/day atorvastatin. In vitro study was performed to see the contribution of blood cells to serum 8-iso-PGF2α. Compared with controls, X-CGD patients had lower platelet, serum, and urinary 8-iso-PGF2α values; conversely, diabetic patients had higher values of 8-iso-PGF2α compared with controls. Urinary 8-iso-PGF2α significantly correlated with both platelet and serum 8-iso-PGF2α in the 2 cohorts. A parallel increase of platelet, serum, and urinary 8-iso-PGF2α by aspirin and a parallel decrease by aspirin plus atorvastatin were detected in the interventional study. In vitro study demonstrated that platelets contribute to 37% of serum 8-iso-PGF2α and that only 13% of it is of extravascular origin., Conclusions: The study suggests that NOX2 contributes to the formation of 8-iso-PGF2α in both platelets and urine. The direct correlation between platelet and urinary 8-iso-PGF2α suggests that, at least partly, urinary 8-iso-PGF2α reflects platelet 8-iso-PGF2α production. Analysis of serum 8-iso-PGF2α may represent a novel tool to investigate the production of 8-iso-PGF2α by blood cells including platelets., Clinical Trial Registration: URL: ClinicalTrials.gov. Unique Identifier: NCT01250340.

Subtherapeutic international normalized ratio (INR) is frequently encountered in clinical practice, and patients with high-risk atrial fibrillation (AF) and with mechanical heart valve (MHV) with inadequate anticoagulation may be exposed to an increased risk of thromboembolic events (TE). However, there are no prospective data evaluating this risk. Consecutive patients with a history of stable anticoagulation, but with a subtherapeutic INR, were prospectively included. Data on use and dose of low-molecular weight heparin (LMWH) bridging therapy were collected. The incidence of objectively confirmed TE and of major bleeding events within 90 days after the index INR was assessed. Five hundred and one patients with INR value 0.5-1 INR units below the lower limit of the patient-specific target INR were included in the study (280 with MHV and 221 with AF and CHADS2 score ≥3). LMWH was prescribed for 64 patients (12.8%). During follow-up, seven patients had a TE (1.40%; 95% confidence interval 0.68, 2.86%; 5.58 events for 100 patients year). All the events occurred within 14 days after the index INR. When we consider only patients who did not receive bridging therapy, the incidence of TE was 1.14% (5 of 437 patients; 95% confidence interval 0.49, 2.64%; 4.58 events for 100 patients year). There were no major bleeding events. The risk of TE in this population was not negligible. Given the frequent observation of subtherapeutic INR levels when monitoring vitamin K antagonists, this finding warrants additional investigation to improve the management of these patients., (Copyright © 2012 Wiley Periodicals, Inc.)

Background: In patients with cirrhosis conflicting findings, inherent to platelet function and its clinical implication, are still matters of discussion. Cirrhosis is characterized by enhanced production of isoprostanes, index of oxidative stress in vivo, that is known to stem from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2)-generating oxidative stress and elicit platelet activation., Aim: To analyse the relationship between oxidative stress and platelet activation in cirrhosis., Methods: A cross-sectional study including 51 cirrhotic patients and sex- and age-matched control patients has been designed. Soluble NOX2-derived peptide (sNOX2-dp), a direct marker of NADPH oxidase activation, isoprostanes urinary excretion, platelet isoprostanes and two markers of in vivo platelet activation, i.e. soluble CD40 Ligand (sCD40L) and soluble P-selectin (sPs), were measured., Results: Compared with controls, cirrhotic patients had higher levels of sPs (P = 0.034), sCD40L (P < 0.0001), sNOX2-dp (P = 0.0016), urinary excretion of isoprostanes (P < 0.0001) and arachidonic acid-induced platelet isoprostane formation (P < 0.0001). A significant correlation between sNOX2-dp and platelet (R(s) = 0.39, P = 0.0051) and urinary (R(s) = 0.67, P < 0.0001) isoprostanes was detected; also, sNOX2-dp and isoprostanes significantly correlated with sPs and sCD40L. A stepwise regression analysis revealed that sNOX2-dp was independently related to sCD40L plasma levels., Conclusions: This study provides evidence that in cirrhosis, platelet isoprostanes are over-produced and could be implicated in platelet activation., (© 2011 John Wiley & Sons A/S.)