549 research outputs found

    Variability approaching the thermal limits can drive diatom community dynamics

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    Organismal distributions are largely mediated by temperature, suggesting thermal trait variability plays a key role in defining species\u27 niches. We employed a trait‐based approach to better understand how inter‐ and intraspecific thermal trait variability could explain diatom community dynamics using 24 strains from 5 species in the diatom genusSkeletonema, isolated from Narragansett Bay (NBay), where this genus can comprise up to 99% of the microplankton. Strain‐specific thermal reaction norms were generated using growth rates obtained at temperatures ranging from −2°C to 36°C. Comparison of thermal reaction norms revealed inter‐ and intraspecific similarities in the thermal optima, but significant differences approaching the thermal limits. Cellular elemental composition was determined for two thermally differentiated species and again, the most variation occurred approaching the thermal limits. To determine the potential impact of interspecific variability on community composition, a species succession model was formulated utilizing each species\u27 empirically determined thermal reaction norm and historical temperature data from NBay. Seasonal succession in the modeled community resembled the timing of species occurrence in the field, but not species\u27 relative abundance. The model correctly predicted the timing of the dominant winter–spring species, Skeletonema marinoi, within 0–14 d of its observed peak occurrence in the field. Interspecific variability approaching the thermal limits provides an alternative mechanism for temporal diatom succession, leads to altered cellular elemental composition, and thus has the potential to influence carbon flux and nutrient cycling, suggesting that growth approaching the thermal limits be incorporated into both empirical and modeling efforts in the future

    Enoxaparin for primary thromboprophylaxis in ambulatory patients with coronavirus disease-2019 (the OVID study): a structured summary of a study protocol for a randomized controlled trial.

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    The OVID study will demonstrate whether prophylactic-dose enoxaparin improves survival and reduces hospitalizations in symptomatic ambulatory patients aged 50 or older diagnosed with COVID-19, a novel viral disease characterized by severe systemic, pulmonary, and vessel inflammation and coagulation activation. The OVID study is conducted as a multicentre open-label superiority randomised controlled trial. Inclusion Criteria 1. Signed patient informed consent after being fully informed about the study's background. 2. Patients aged 50 years or older with a positive test for SARS-CoV2 in the past 5 days and eligible for ambulatory treatment. 3. Presence of respiratory symptoms (i.e. cough, sore throat, or shortness of breath) or body temperature >37.5° C. 4. Ability of the patient to travel to the study centre by private transportation, performed either by an accompanying person from the same household or by the patient themselves 5. Ability to comply with standard hygiene requirements at the time of in-hospital visit, including a face mask and hand disinfectant. 6. Ability to walk from car to study centre or reach it by wheelchair transport with the help of an accompanying person from the same household also complying with standard hygiene requirements. 7. Ability to self-administer prefilled enoxaparin injections after instructions received at the study centre or availability of a person living with the patient to administer enoxaparin. Exclusion Criteria 1. Any acute or chronic condition posing an indication for anticoagulant treatment, e.g. atrial fibrillation, prior venous thromboembolism (VTE), acute confirmed symptomatic VTE, acute coronary syndrome. 2. Anticoagulant thromboprophylaxis deemed necessary in view of the patient's history, comorbidity or predisposing strong risk factors for thrombosis: a. Any of the following events occurring in the prior 30 days: fracture of lower limb, hospitalization for heart failure, hip/knee replacement, major trauma, spinal cord injury, stroke, b. previous VTE, c. histologically confirmed malignancy, which was diagnosed or treated (surgery, chemotherapy, radiotherapy) in the past 6 months, or recurrent, or metastatic, or inoperable. 3. Any clinically relevant bleeding (defined as bleeding requiring hospitalization, transfusion, surgical intervention, invasive procedures, occurring in a critical anatomical site, or causing disability) within 30 days prior to randomization or sign of acute bleeding. 4. Intracerebral bleeding at any time in the past or signs/symptoms consistent with acute intracranial haemorrhage. 5. Haemoglobin <8 g/dL and platelet count <50 x 10 <sup>9</sup> cells/L confirmed by recent laboratory test (<90 days). 6. Subjects with any known coagulopathy or bleeding diathesis, including known significant liver disease associated with coagulopathy. 7. Severe renal insufficiency (baseline creatinine clearance <30 mL/min calculated using the Cockcroft-Gault formula) confirmed by recent laboratory test (<90 days). 8. Contraindications to enoxaparin therapy, including prior heparin-induced thrombocytopenia and known hypersensitivity. 9. Current use of dual antiplatelet therapy. 10. Participation in other interventional studies over the past 30 days. 11. Non-compliance or inability to adhere to treatment or lack of a family environment or support system for home treatment. 12. Cognitive impairment and/or inability to understand information provided in the study information. Patient enrolment will take place at seven Swiss centres, including five university hospitals and two large cantonal hospitals. Patients randomized to the intervention group will receive subcutaneous enoxaparin at the recommended dose of 4,000 IU anti-Xa activity (40 mg/0.4 ml) once daily for 14 days. Patients randomized to the comparator group will receive no anticoagulation. Primary outcome: a composite of any hospitalization or all-cause death occurring within 30 days of randomization. (i) a composite of cardiovascular events, including deep vein thrombosis (including catheter-associated), pulmonary embolism, myocardial infarction/myocarditis, arterial ischemia including mesenteric and extremities, acute splanchnic vein thrombosis, or ischemic stroke within 14 days, 30 days, and 90 days of randomization; (ii) each component of the primary efficacy outcome, within 14 days, 30 days, and 90 days of randomization; (iii) net clinical benefit (accounting for the primary efficacy outcome, composite cardiovascular events, and major bleeding), within 14 days, 30 days, and 90 days of enrolment; (iv) primary efficacy outcome, within 14 days, and 90 days of enrolment; (v) disseminated intravascular coagulation (ISTH criteria, in-hospital diagnosis) within 14 days, 30 days, and 90 days of enrolment. Patients will undergo block stratified randomization (by age: 50-70 vs. >70 years; and by study centre) with a randomization ratio of 1:1 with block sizes varying between 4 and 8. Randomization will be performed after the signature of the informed consent for participation and the verification of the eligibility criteria using the electronic data capture software (REDCAP, Vanderbilt University, v9.1.24). In this open-label study, no blinding procedures will be used. The sample size calculation is based on the parameters α = 0.05 (2-sided), power: 1-β = 0.8, event rate in experimental group, pexp = 0.09 and event rate in control group, pcon = 0.15. The resulting total sample size is 920. To account for potential dropouts, the total sample size was fixed to 1000 with 500 patients in the intervention group and 500 in the control group. Protocol version 1.0, 14 April 2020. Protocol version 3.0, 18 May 2020 Recruiting start date: June 2020. Last Patient Last Visit: March 2021. ClinicalTrials.gov Identifier: NCT04400799 First Posted: May 26, 2020 Last Update Posted: July 16, 2020 FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol

    Diabetes and baseline glucose are associated with inflammation, left ventricular function and short- and long-term outcome in acute coronary syndromes: role of the novel biomarker Cyr 61.

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    Hyperglycemia in the setting of an acute coronary syndrome (ACS) impacts short term outcomes, but little is known about longer term effects. We therefore designed this study to firstly determine the association between hyperglycemia and short term and longer term outcomes in patients presenting with ACS and secondly evaluate the prognostic role of diabetes, body mass index (BMI) and the novel biomarker Cyr61 on outcomes. The prospective Special Program University Medicine-Acute Coronary Syndrome (SPUM-ACS) cohort enrolled 2168 patients with ACS between December 2009 and October 2012, of which 2034 underwent PCI (93.8%). Patients were followed up for 12 months. Events were independently adjudicated by three experienced cardiologists. Participants were recruited from four tertiary hospitals in Switzerland: Zurich, Geneva, Lausanne and Bern. Participants presenting with acute coronary syndromes and who underwent coronary angiography were included in the analysis. Patients were grouped according to history of diabetes (or HbA1c greater than 6%), baseline blood sugar level (BSL; < 6, 6-11.1 and > 11.1 mmol/L) and body mass index (BMI). The primary outcome was major adverse cardiac events (MACE) which was a composite of myocardial infarction, stroke and all-cause death. Secondary outcomes included the individual components of the primary endpoint, revascularisations, bleeding events (BARC classification) and cerebrovascular events (ischaemic or haemorrhagic stroke or TIA). Patients with hyperglycemia, i.e. BSL ≥ 11.1 mmol/L, had higher levels of C-reactive protein (CRP), white blood cell count (WBC), creatinine kinase (CK), higher heart rates and lower left ventricular ejection fraction (LVEF) and increased N-terminal pro-brain natriuretic peptide. At 30 days and 12 months, those with BSL ≥ 11.1 mmol/L had more MACE and death compared to those with BSL < 6.0 mmol/L or 6.0-11.1 mmol/L (HR-ratio 4.78 and 6.6; p < 0.001). The novel biomarker Cyr61 strongly associated with high BSL and STEMI and was independently associated with 1 year outcomes (HR 2.22; 95% CI 1.33-3.72; Tertile 3 vs. Tertile 1). In this large, prospective, independently adjudicated cohort of in all comers ACS patients undergoing PCI, both a history of diabetes and elevated entry glucose was associated with inflammation and increased risk of MACE both at short and long-term. The mediators might involve increased sympathetic activation, inflammation and ischemia as reflected by elevated Cyr61 levels leading to larger levels of troponin and lower LVEF. Trial registration Clinical Trial Registration Number: NCT01000701. Registered October 23, 2009

    Incidence, Predictors, and Clinical Impact of Early Prasugrel Cessation in Patients With ST-Elevation Myocardial Infarction.

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    BACKGROUND: Early withdrawal of recommended antiplatelet treatment with clopidogrel adversely affects prognosis following percutaneous coronary interventions. Optimal antiplatelet treatment is essential following ST-segment elevation myocardial infarction (STEMI) given the increased risk of thrombotic complications. This study assessed the frequency, predictors, and clinical impact of early prasugrel cessation in patients with STEMI undergoing primary percutaneous coronary interventions. METHODS AND RESULTS: We pooled patients with STEMI discharged on prasugrel in 2 prospective registries (Bern PCI Registry [NCT02241291] and SPUM-ACS (Inflammation and Acute Coronary Syndromes) [NCT01000701]) and 1 STEMI trial (COMFORTABLE-AMI (Comparison of Biomatrix Versus Gazelle in ST-Elevation Myocardial Infarction) [NCT00962416]). Prasugrel treatment status at 1 year was categorized as no cessation; crossover to another P2Y12-inhibitor; physician-recommended discontinuation; and disruption because of bleeding, side effects, or patient noncompliance. In time-dependent analyses, we assessed the impact of prasugrel cessation on the primary end point, a composite of cardiac death, myocardial infarction, and stroke. Of all 1830 included patients (17% women, mean age 59 years), 83% were treated with new-generation drug-eluting stents. At 1 year, any prasugrel cessation had occurred in 13.8% of patients including crossover (7.2%), discontinuation (3.7%), and disruption (2.9%). Independent predictors of any prasugrel cessation included female sex, age, and history of cerebrovascular event. The primary end point occurred in 5.2% of patients and was more frequent following disruption (hazard ratio 3.04, 95% confidence interval,1.34-6.91; P=0.008), without significant impact of crossover or discontinuation. Consistent findings were observed for all-cause death, myocardial infarction, and stent thrombosis following prasugrel disruption. CONCLUSIONS: In this contemporary study of patients with STEMI, early prasugrel cessation was not uncommon and primarily involved change to another P2Y12-inhibitor. Disruption was the only type of early prasugrel cessation associated with statistically significant excess in ischemic risk within 1 year following primary percutaneous coronary interventions

    Quantitative Flow Ratio to Predict Nontarget Vessel-Related Events at 5 Years in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Angiography-Guided Revascularization.

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    Background In ST-segment-elevation myocardial infarction, angiography-based complete revascularization is superior to culprit-lesion-only percutaneous coronary intervention. Quantitative flow ratio (QFR) is a novel, noninvasive, vasodilator-free method used to assess the hemodynamic significance of coronary stenoses. We aimed to investigate the incremental value of QFR over angiography in nonculprit lesions in patients with ST-segment-elevation myocardial infarction undergoing angiography-guided complete revascularization. Methods and Results This was a retrospective post hoc QFR analysis of untreated nontarget vessels (any degree of diameter stenosis [DS]) from the randomized multicenter COMFORTABLE AMI (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Metal Stents in Acute ST-Elevation Myocardial Infarction) trial by assessors blinded for clinical outcomes. The primary end point was cardiac death, spontaneous nontarget vessel myocardial infarction, and clinically indicated nontarget vessel revascularization (ie, ≥70% DS by 2-dimensional quantitative coronary angiography or ≥50% DS and ischemia) at 5 years. Of 1161 patients with ST-segment-elevation myocardial infarction, 946 vessels in 617 patients were analyzable by QFR. At 5 years, the rate of the primary end point was significantly higher in patients with QFR ≤0.80 (n=35 patients, n=36 vessels) versus QFR >0.80 (n=582 patients, n=910 vessels) (62.9% versus 12.5%, respectively; hazard ratio [HR], 7.33 [95% CI, 4.54-11.83], P30% DS by 3-dimensional quantitative coronary angiography. Conclusions Our study suggests incremental value of QFR over angiography-guided percutaneous coronary intervention for nonculprit lesions among patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention

    Proceedings from the 2nd European Clinical Consensus Conference for device-based therapies for hypertension: state of the art and considerations for the future.

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    The interest in RDN for hypertension has fluctuated recently, with a flurry of initial enthusiasm followed by sudden loss of interest by researchers and device manufacturers, with an almost as sudden resurgence in clinical trials activity and device innovation more recently. There is widespread consensus that this therapeutic strategy can be effective, at least for some of the technologies available. Major uncertainties remain as to the clinical role of RDN, and whether any of the emerging technologies such as AV-anastomosis formation, carotid body ablation, carotid bulb expansion, or baroreflex stimulation will have a future as effective treatment options in patients with hypertension. In our first consensus report in 2015, the European Expert Group pointed to the major unmet need of standardization of measurements, trial design and procedural performance.6 With the large number of different technologies currently in the pipeline, this need has even increased. Only through high-quality, collaborative research and openness to new methods for recruitment, patient selection, and assessment of outcomes will it be possible to establish incontrovertibly whether device therapies for hypertension are effective and what are preferred patient populations. Once the proof of concept is established, further studies with a design relevant to clinical reality will be needed to establish the place of new devices in the treatment armoury. The clinical and research community has a large responsibility to prove or disprove the value of new therapies, in order to ensure that antihypertensive devices provide future patients with the greatest benefit and the smallest risk. copy; The Author 2017
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