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1.
N Engl J Med ; 389(16): 1477-1487, 2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37634149

RESUMEN

BACKGROUND: Imaging-guided percutaneous coronary intervention (PCI) is associated with better clinical outcomes than angiography-guided PCI. Whether routine optical coherence tomography (OCT) guidance in PCI of lesions involving coronary-artery branch points (bifurcations) improves clinical outcomes as compared with angiographic guidance is uncertain. METHODS: We conducted a multicenter, randomized, open-label trial at 38 centers in Europe. Patients with a clinical indication for PCI and a complex bifurcation lesion identified by means of coronary angiography were randomly assigned in a 1:1 ratio to OCT-guided PCI or angiography-guided PCI. The primary end point was a composite of major adverse cardiac events (MACE), defined as death from a cardiac cause, target-lesion myocardial infarction, or ischemia-driven target-lesion revascularization at a median follow-up of 2 years. RESULTS: We assigned 1201 patients to OCT-guided PCI (600 patients) or angiography-guided PCI (601 patients). A total of 111 patients (18.5%) in the OCT-guided PCI group and 116 (19.3%) in the angiography-guided PCI group had a bifurcation lesion involving the left main coronary artery. At 2 years, a primary end-point event had occurred in 59 patients (10.1%) in the OCT-guided PCI group and in 83 patients (14.1%) in the angiography-guided PCI group (hazard ratio, 0.70; 95% confidence interval, 0.50 to 0.98; P = 0.035). Procedure-related complications occurred in 41 patients (6.8%) in the OCT-guided PCI group and 34 patients (5.7%) in the angiography-guided PCI group. CONCLUSIONS: Among patients with complex coronary-artery bifurcation lesions, OCT-guided PCI was associated with a lower incidence of MACE at 2 years than angiography-guided PCI. (Funded by Abbott Vascular and others; OCTOBER ClinicalTrials.gov number, NCT03171311.).


Asunto(s)
Angiografía Coronaria , Enfermedad de la Arteria Coronaria , Intervención Coronaria Percutánea , Tomografía de Coherencia Óptica , Humanos , Angiografía Coronaria/efectos adversos , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/terapia , Intervención Coronaria Percutánea/efectos adversos , Intervención Coronaria Percutánea/métodos , Tomografía de Coherencia Óptica/efectos adversos , Tomografía de Coherencia Óptica/métodos , Resultado del Tratamiento , Europa (Continente)
2.
Physiol Plant ; 176(3): e14311, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38715208

RESUMEN

Although microalgae have only recently been recognized as part of the plant and soil microbiome, their application as biofertilizers has a tradition in sustainable crop production. Under consideration of their ability to produce the plant growth-stimulating hormone cytokinin (CK), known to also induce pathogen resistance, we have assessed the biocontrol ability of CK-producing microalgae. All pro- and eukaryotic CK-producing microalgae tested were able to enhance the tolerance of tobacco against Pseudomonas syringae pv. tabaci (PsT) infection. Since Chlamydomonas reinhardtii (Cre) proved to be the most efficient, we functionally characterized its biocontrol ability. We employed the CRISPR-Cas9 system to generate the first knockouts of CK biosynthetic genes in microalgae. Specifically, we targeted Cre Lonely Guy (LOG) and isopentenyltransferase (IPT) genes, the key genes of CK biosynthesis. While Cre wild-type exhibits a strong protection, the CK-deficient mutants have a reduced ability to induce plant defence. The degree of protection correlates with the CK levels, with the IPT mutants showing less protection than the LOG mutants. Gene expression analyses showed that Cre strongly stimulates tobacco resistance through defence gene priming. This study functionally verifies that Cre primes defence responses with CK, which contributes to the robustness of the effect. This work contributes to elucidate microalgae-mediated plant defence priming and identifies the role of CKs. In addition, these results underscore the potential of CK-producing microalgae as biologicals in agriculture by combining biofertilizer and biocontrol ability for sustainable and environment-friendly crop management.


Asunto(s)
Sistemas CRISPR-Cas , Chlamydomonas reinhardtii , Citocininas , Resistencia a la Enfermedad , Nicotiana , Enfermedades de las Plantas , Nicotiana/genética , Nicotiana/microbiología , Nicotiana/inmunología , Citocininas/metabolismo , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/genética , Resistencia a la Enfermedad/genética , Chlamydomonas reinhardtii/genética , Chlamydomonas reinhardtii/metabolismo , Pseudomonas syringae/patogenicidad , Pseudomonas syringae/fisiología , Mutación
3.
Eur Heart J ; 44(41): 4376-4384, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37634144

RESUMEN

BACKGROUND AND AIMS: Guidelines recommend revascularization of intermediate epicardial artery stenosis to be guided by evidence of ischaemia. Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are equally recommended. Individual 5-year results of two major randomized trials comparing FFR with iFR-guided revascularization suggested increased all-cause mortality following iFR-guided revascularization. The aim of this study was a study-level meta-analysis of the 5-year outcome data in iFR-SWEDEHEART (NCT02166736) and DEFINE-FLAIR (NCT02053038). METHODS: Composite of major adverse cardiovascular events (MACE) and its individual components [all-cause death, myocardial infarction (MI), and unplanned revascularisation] were analysed. Raw Kaplan-Meier estimates, numbers at risk, and number of events were extracted at 5-year follow-up and analysed using the ipdfc package (Stata version 18, StataCorp, College Station, TX, USA). RESULTS: In total, iFR and FFR-guided revascularization was performed in 2254 and 2257 patients, respectively. Revascularization was more often deferred in the iFR group [n = 1128 (50.0%)] vs. the FFR group [n = 1021 (45.2%); P = .001]. In the iFR-guided group, the number of deaths, MACE, unplanned revascularization, and MI was 188 (8.3%), 484 (21.5%), 235 (10.4%), and 123 (5.5%) vs. 143 (6.3%), 420 (18.6%), 241 (10.7%), and 123 (5.4%) in the FFR group. Hazard ratio [95% confidence interval (CI)] estimates for MACE were 1.18 [1.04; 1.34], all-cause mortality 1.34 [1.08; 1.67], unplanned revascularization 0.99 [0.83; 1.19], and MI 1.02 [0.80; 1.32]. CONCLUSIONS: Five-year all-cause mortality and MACE rates were increased with revascularization guided by iFR compared to FFR. Rates of unplanned revascularization and MI were equal in the two groups.


Asunto(s)
Estenosis Coronaria , Reserva del Flujo Fraccional Miocárdico , Infarto del Miocardio , Humanos , Estenosis Coronaria/diagnóstico , Vasos Coronarios , Cateterismo Cardíaco , Angiografía Coronaria , Índice de Severidad de la Enfermedad , Valor Predictivo de las Pruebas
4.
Eur Heart J ; 44(6): 502-512, 2023 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-36329643

RESUMEN

BACKGROUND: Long-term prognostic implications of serial high-sensitivity troponin concentrations in subjects with suspected acute coronary syndrome are unknown. METHODS AND RESULTS: Individuals with a first diagnosis of myocardial infarction, unstable angina, observation for suspected myocardial infarction, or chest pain from 2012 through 2019 who underwent two high-sensitivity troponin-T (hsTnT) measurements 1-7 h apart were identified through Danish national registries. Absolute and relative risks for death at days 0-30 and 31-365, stratified for whether subjects had normal or elevated hsTnT concentrations, and whether these concentrations changed by <20%, > 20 to 50%, or >50% in either direction from first to second measurement, were calculated through multivariable logistic regression with average treatment effect modeling. Of the 28 902 individuals included, 2.8% had died at 30 days, whereas 4.9% of those who had survived the first 30 days died between days 31-365. The standardized risk of death was highest among subjects with two elevated hsTnT concentrations (0-30 days: 4.3%, 31-365 days: 7.2%). In this group, mortality was significantly higher in those with a > 20 to 50% or >50% rise from first to second measurement, though only at 30 days. The risk of death was very low in subjects with two normal hsTnT concentrations (0-30 days: 0.1%, 31-365 days: 0.9%) and did not depend on relative or absolute changes between measurements. CONCLUSIONS: Individuals with suspected acute coronary syndrome and two consecutively elevated hsTnT concentrations consistently had the highest risk of death. Mortality was very low in subjects with two normal hsTnT concentrations, irrespective of changes between measurements.


Asunto(s)
Síndrome Coronario Agudo , Infarto del Miocardio , Troponina T , Humanos , Síndrome Coronario Agudo/diagnóstico , Biomarcadores , Modelos Logísticos , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/terapia
5.
Am Heart J ; 257: 41-50, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36423733

RESUMEN

BACKGROUND: Chronic total occlusions (CTO) are frequent among patients with coronary artery disease. Revascularization with percutaneous coronary intervention (PCI) is safe and feasible in experienced hands. However, randomized data are needed to demonstrate symptomatic as well as prognostic effect of CTO-PCI compared to optimal medical therapy alone. METHODS: This trial aims to evaluate the effect of CTO PCI in patients with a CTO lesion and target vessel diameter ≥ 2.5 mm, and myocardial ischemia in the relevant territory. First, all patients are subjected to optimal medical therapy (OMT) for at least for 3 months and non-CTO lesions are managed according to guidelines. Subsequently, prior to randomization myocardial ischemia and quality of life (Seattle Questionnaire (SAQ)) is assessed. Patients are divided into two cohorts based on their SAQ score and randomized to either OMT alone or OMT and CTO-PCI. Cohort A is defined as Low- or asymptomatic patients with a quality-of-life score > 60 and/or CCS class < 2, and more than 10 % ischemia in the left ventricle (LV). Cohort B is symptomatic patients with a quality-of-life score < 60 or CCS class angina > 1 and at least ischemia in 5% of the LV. The primary end-point in cohort A is a composite of major adverse cardiac and cerebral events, hospitalization for heart failure and malignant ventricular arrhythmias. The primary endpoint in cohort B is difference in quality of life 6 months after randomization. IMPLICATIONS: This trial is designed to investigate if CTO-PCI improves QoL and MACCE. Both positive and negative outcome of the trial will affect future guidelines and recommendations on how to treat patients with CTO.


Asunto(s)
Enfermedad de la Arteria Coronaria , Oclusión Coronaria , Intervención Coronaria Percutánea , Humanos , Oclusión Coronaria/cirugía , Enfermedad de la Arteria Coronaria/etiología , Calidad de Vida , Intervención Coronaria Percutánea/efectos adversos , Angina de Pecho/etiología , Enfermedad Crónica , Resultado del Tratamiento
6.
Cogn Psychol ; 145: 101591, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37586285

RESUMEN

Statements containing epistemic modals (e.g., "by spring 2023 most European countries may have the Covid-19 pandemic under control") are common expressions of epistemic uncertainty. In this paper, previous published findings (Knobe & Yalcin, 2014; Khoo & Phillips, 2018) on the opposition between Contextualism and Relativism for epistemic modals are re-examined. It is found that these findings contain a substantial degree of individual variation. To investigate whether participants differ in their interpretations of epistemic modals, an experiment with multiple phases and sessions is conducted to classify participants according to the three semantic theories of Relativism, Contextualism, and Objectivism. Through this study, some of the first empirical evidence for the kind of truth-value shifts postulated by semantic Relativism is presented. It is furthermore found that participants' disagreement judgments match their truth evaluations and that participants are capable of distinguishing between truth and justification. In a second experimental session, it is investigated whether participants thus classified follow the norm of retraction which Relativism uses to account for argumentation with epistemic modals. Here the results are less favorable for Relativism. In a second experiment, these results are replicated and the normative beliefs of participants concerning the norm of retraction are investigated following work on measuring norms by Bicchieri (2017). Again, it is found that on average participants show no strong preferences concerning the norm of retraction for epistemic modals. Yet, it was found that participants who had committed to Objectivism and had training in logic applied the norm of retraction to might-statements. These results present a substantial challenge to the account of argumentation with epistemic modals presented in MacFarlane (2014), as discussed.


Asunto(s)
COVID-19 , Pandemias , Humanos , Semántica , Juicio , Incertidumbre
7.
Europace ; 25(3): 931-939, 2023 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-36520640

RESUMEN

AIMS: Emerging data show that complete revascularization (CR) reduces cardiovascular death and recurrent myocardial infarction in ST-segment elevation myocardial infarction (STEMI). However, the influence of revascularization status on development of arrhythmia in the long-term post-STEMI phase is poorly described. We hypothesized that incomplete revascularization (ICR) compared with CR in STEMI is associated with an increased long-term risk of new-onset arrhythmia. METHODS AND RESULTS: Patients with STEMI treated with primary percutaneous coronary intervention (PPCI) at Copenhagen University Hospital, Rigshospitalet, Denmark, with CR or ICR were identified via the Eastern Danish Heart registry from 2009 to 2016. Using unique Danish administrative registries, the outcomes were assessed. The primary outcome was new-onset arrhythmia defined as a composite of atrial fibrillation/flutter (AF), sinoatrial block, advanced second- or third-degree atrioventricular block, ventricular tachycardia/fibrillation (VT), or cardiac arrest (CA), with presentation >7 days post-PPCI. Secondary outcomes were the components of the primary outcome and all-cause mortality. A total of 5103 patients (median age: 62.0 years; 76% men) were included, of whom 4009 (79%) and 1094 (21%) patients underwent CR and ICR, respectively. Compared with CR, ICR was associated with a higher risk of new-onset arrhythmia [hazard ratio (HR), 1.33; 95% confidence interval (CI), 1.07-1.66; P = 0.01], AF (HR, 1.29; 95% CI, 1.00-1.66; P = 0.05), a combined outcome of VT and CA (HR, 1.77; 95% CI, 1.10-2.84; P = 0.02) and all-cause mortality (HR, 1.27; 95% CI, 1.05-1.53; P = 0.01). All HRs adjusted. CONCLUSION: Among patients with STEMI, ICR was associated with an increased long-term risk of new-onset arrhythmia and all-cause mortality compared with CR.


Asunto(s)
Fibrilación Atrial , Intervención Coronaria Percutánea , Infarto del Miocardio con Elevación del ST , Taquicardia Ventricular , Masculino , Humanos , Persona de Mediana Edad , Femenino , Infarto del Miocardio con Elevación del ST/diagnóstico , Infarto del Miocardio con Elevación del ST/terapia , Infarto del Miocardio con Elevación del ST/complicaciones , Resultado del Tratamiento , Fibrilación Ventricular/etiología , Taquicardia Ventricular/etiología , Intervención Coronaria Percutánea/efectos adversos , Fibrilación Atrial/complicaciones , Factores de Riesgo
8.
Sleep Breath ; 27(4): 1611-1618, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36178574

RESUMEN

PURPOSE: We evaluated whether or not changes in body composition following moderate hypoxic exposure for 4 weeks were different compared to sea level exposure. METHODS: In a randomized crossover design, nine trained participants were exposed to 2320 m of altitude or sea level for 4 weeks, separated by > 3 months. Body fat percentage (BF%), fat mass (FM), and fat-free mass (FFM) were determined before and after each condition by dual X-ray absorptiometry (DXA) and weekly by a bioelectrical impedance scanner to determine changes with a high resolution. Training volume was quantified during both interventions. RESULTS: Hypoxic exposure reduced (P < 0.01) BF% by 2 ± 1 percentage points and increased (P < 0.01) FFM by 2 ± 2% determined by DXA. A tending time × treatment effect existed for FM determined by DXA (P = 0.06), indicating a reduced FM in hypoxia by 8 ± 7% (P < 0.01). Regional body analysis revealed reduced (P < 0.01) BF% and FFM and an increased (P < 0.01) FFM in the truncus area. No changes were observed following sea level. Bioelectrical impedance determined that BF%, FM, and FFM did not reveal any differences between interventions. Urine specific gravity measured simultaneously as body composition was identical. Training volume was similar between interventions (509 ± 70 min/week vs. 432 ± 70 min/week, respectively). CONCLUSIONS: Four weeks of altitude exposure reduced BF% and increased FFM in trained individuals as opposed to sea level exposure. The results also indicate that a decrease in FM is greater at altitude compared to sea level. Changes were specifically observed in the truncus area.


Asunto(s)
Tejido Adiposo , Composición Corporal , Humanos , Estudios Cruzados , Absorciometría de Fotón , Impedancia Eléctrica , Índice de Masa Corporal
9.
New Phytol ; 236(2): 774-791, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35851958

RESUMEN

Convolutional neural networks (CNNs) are a powerful tool for plant image analysis, but challenges remain in making them more accessible to researchers without a machine-learning background. We present RootPainter, an open-source graphical user interface based software tool for the rapid training of deep neural networks for use in biological image analysis. We evaluate RootPainter by training models for root length extraction from chicory (Cichorium intybus L.) roots in soil, biopore counting, and root nodule counting. We also compare dense annotations with corrective ones that are added during the training process based on the weaknesses of the current model. Five out of six times the models trained using RootPainter with corrective annotations created within 2 h produced measurements strongly correlating with manual measurements. Model accuracy had a significant correlation with annotation duration, indicating further improvements could be obtained with extended annotation. Our results show that a deep-learning model can be trained to a high accuracy for the three respective datasets of varying target objects, background, and image quality with < 2 h of annotation time. They indicate that, when using RootPainter, for many datasets it is possible to annotate, train, and complete data processing within 1 d.


Asunto(s)
Aprendizaje Profundo , Procesamiento de Imagen Asistido por Computador/métodos , Aprendizaje Automático , Redes Neurales de la Computación , Suelo
10.
Plant Cell Environ ; 45(3): 823-836, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34806183

RESUMEN

Deep rooting winter wheat genotypes can reduce nitrate leaching losses and increase N uptake. We aimed to investigate which deep root traits are correlated to deep N uptake and to estimate genetic variation in root traits and deep 15 N tracer uptake. In 2 years, winter wheat genotypes were grown in RadiMax, a semifield root-screening facility. Minirhizotron root imaging was performed three times during the main growing season. At anthesis, 15 N was injected via subsurface drip irrigation at 1.8 m depth. Mature ears from above the injection area were analysed for 15 N content. From minirhizotron image-based root length data, 82 traits were constructed, describing root depth, density, distribution and growth aspects. Their ability to predict 15 N uptake was analysed with the least absolute shrinkage and selection operator (LASSO) regression. Root traits predicted 24% and 14% of tracer uptake variation in 2 years. Both root traits and genotype showed significant effects on tracer uptake. In 2018, genotype and the three LASSO-selected root traits predicted 41% of the variation in tracer uptake, in 2019 genotype and one root trait predicted 48%. In both years, one root trait significantly mediated the genotype effect on tracer uptake. Deep root traits from minirhizotron images can predict deep N uptake, indicating the potential to breed deep-N-uptake-genotypes.


Asunto(s)
Nitratos , Raíces de Plantas , Genotipo , Fenotipo , Raíces de Plantas/genética , Triticum/genética
11.
J Chem Phys ; 156(19): 194502, 2022 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-35597661

RESUMEN

Dynamic shear-modulus data are presented for two silicone oils DC704 and DC705 for frequencies between 1 mHz and 10 kHz at temperatures covering more than five decades of relaxation-time variation. Data are fitted to the alpha part of a phenomenological model previously shown to describe well the dynamic shear modulus of squalane, which has a large beta process [Hecksher et al., J. Chem. Phys. 146, 154504 (2017)]. That model is characterized by additivity of the alpha and beta shear compliance and by a high-frequency decay of the alpha process in proportion to ω-1/2, where ω is the angular frequency. The fits of the alpha part of this model to the DC704 and DC705 data are compared to fits by a Havriliak-Negami type model, a Barlow-Erginsav-Lamb model, and a Cole-Davidson type model. At all temperatures, the best fit is obtained by the alpha part of the squalane model. This strengthens the conjecture that so-called t-relaxation, leading to high-frequency loss decays proportional to ω-1/2, is generic to the alpha relaxation of supercooled liquids [J. C. Dyre, Phys. Rev. E 74, 021502 (2006); Nielsen et al., J. Chem. Phys. 130, 154508 (2009); and Pabst et al., J. Phys. Chem. Lett. 12, 3685-3690 (2021)].

12.
Proc Natl Acad Sci U S A ; 116(34): 16736-16741, 2019 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-31391307

RESUMEN

This paper presents physical-aging data for the silicone oil tetramethyl-tetraphenyl trisiloxane. The density and the high-frequency plateau shear modulus [Formula: see text] were monitored following temperature jumps starting from fully equilibrated conditions. Both quantities exhibit a fast change immediately after a temperature jump. Adopting the material-time formalism of Narayanaswamy, we determine from the dielectric loss at 0.178 Hz the time evolution of the aging-rate activation energy. The relative magnitude of the fast change of the activation energy differs from that of the density, but is identical to that of [Formula: see text] In fact, the activation energy is proportional to [Formula: see text] throughout the aging process, with minor deviations at the shortest times. This shows that for the silicone oil in question the dynamics are determined by [Formula: see text] in-as well as out of-equilibrium.

13.
J Anaesthesiol Clin Pharmacol ; 38(4): 580-587, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36778814

RESUMEN

Background and Aims: Anesthesia often reduces mean arterial pressure (MAP) to a level that may compromise cerebral blood flow. We evaluated whether phenylephrine treatment of anesthesia-induced hypotension affects internal carotid artery (ICA) blood flow and whether anesthesia affects ICA flow and CO2 reactivity. Material and Methods: The study included twenty-seven patients (65 ± 11 years; mean ± SD) undergoing esophageal resection (n = 14), stomach resection (n = 12), or a gastroentero anastomosis (n = 1) during combined propofol-remifentanil and thoracic epidural anesthesia. Duplex ultrasound evaluated ICA blood flow. Evaluations were before and after induction of anesthesia, before and after the administration of phenylephrine as part of standard care to treat anesthesia-induced hypotension at a MAP below 60 mmHg, and the hypocapnic reactivity of ICA flow was determined before and during anesthesia. Results: Induction of anesthesia reduced MAP from 108 ± 12 to 66 ± 16 mmHg (P < 0.0001) and ICA flow from 340 ± 92 to 196 ± 52 mL/min (P < 0.0001). Phenylephrine was administered to 24 patients (0.1-0.2 mg) and elevated MAP from 53 ± 8 to 73 ± 8 mmHg (P = 0.0001) and ICA flow from 191 ± 43 to 218 ± 50 mL/min (P = 0.0276). Furthermore, anesthesia reduced the hypocapnic reactivity of ICA flow from 23 (18-33) to 14%/kPa (10-22; P = 0.0068). Conclusion: Combined propofol-remifentanil and thoracic epidural anesthesia affect ICA flow and CO2 reactivity. Phenylephrine partly restored ICA flow indicating that anesthesia-induced hypotension contributes to the reduction in ICA flow.

14.
Am J Physiol Heart Circ Physiol ; 321(5): H865-H880, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34448636

RESUMEN

Myocardial function and exercise reserve are important determinants of outcome in pulmonary arterial hypertension (PAH) but are incompletely understood. For this study, we performed subject-specific computer simulations, based on invasive measurements and cardiac magnetic resonance imaging (CMR), to investigate whole circulation properties in PAH at rest and exercise and determinants of exercise reserve. CMR and right heart catheterization were performed in nine patients with idiopathic PAH, and CMR in 10 healthy controls. CMR during exercise was performed in seven patients with PAH. A full-circulation computer model was developed, and model parameters were optimized at the individual level. Patient-specific simulations were used to analyze the effect of right ventricular (RV) inotropic reserve on exercise performance. Simulations achieved a high consistency with observed data. RV contractile force was increased in patients with PAH (127.1 ± 28.7 kPa vs. 70.5 ± 14.5 kPa, P < 0.001), whereas left ventricular contractile force was reduced (107.5 ± 17.5 kPa vs. 133.9 ± 10.3 kPa, P = 0.002). During exercise, RV contractile force increased by 1.56 ± 0.17, P = 0.001. In silico experiments confirmed RV inotropic reserve as the important limiting factor for cardiac output. Subject-specific computer simulation of myocardial mechanics in PAH is feasible and can be used to evaluate myocardial performance. With this method, we demonstrate marked functional myocardial adaptation to PAH in the resting state, primarily composed of increased contractile force development by RV myofibers, and we show the negative impact of reduced RV inotropic reserve on cardiac output during exercise.NEW & NOTEWORTHY Computer simulations of the myocardial mechanics and hemodynamics of rest and exercise were performed in nine patients with pulmonary arterial hypertension and 10 control subjects, with the use of data from invasive catheterization and from cardiac magnetic resonance. This approach allowed a detailed analysis of myocardial adaptation to pulmonary arterial hypertension and showed how reduction in right ventricular inotropic reserve is the important limiting factor for an increase in cardiac output during exercise.


Asunto(s)
Cateterismo Cardíaco , Tolerancia al Ejercicio , Hipertensión Pulmonar Primaria Familiar/diagnóstico , Ventrículos Cardíacos/diagnóstico por imagen , Hemodinámica , Imagen por Resonancia Cinemagnética , Modelos Cardiovasculares , Modelación Específica para el Paciente , Función Ventricular Derecha , Adaptación Fisiológica , Adulto , Estudios de Casos y Controles , Prueba de Esfuerzo , Hipertensión Pulmonar Primaria Familiar/diagnóstico por imagen , Hipertensión Pulmonar Primaria Familiar/fisiopatología , Femenino , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas
15.
Am J Physiol Regul Integr Comp Physiol ; 321(2): R152-R161, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-34160288

RESUMEN

Current markers of iron deficiency (ID), such as ferritin and hemoglobin, have shortcomings, and hepcidin and erythroferrone (ERFE) could be of clinical relevance in relation to early assessment of ID. Here, we evaluate whether exposure to altitude-induced hypoxia (2,320 m) alone, or in combination with recombinant human erythropoietin (rHuEPO) treatment, affects hepcidin and ERFE levels before alterations in routine ID biomarkers and stress erythropoiesis manifest. Two interventions were completed, each comprising a 4-wk baseline, a 4-wk intervention at either sea level or altitude, and a 4-wk follow-up. Participants (n = 39) were randomly assigned to 20 IU·kg body wt-1 rHuEPO or placebo injections every second day for 3 wk during the two intervention periods. Venous blood was collected weekly. Altitude increased ERFE (P ≤ 0.001) with no changes in hepcidin or routine iron biomarkers, making ERFE of clinical relevance as an early marker of moderate hypoxia. rHuEPO treatment at sea level induced a similar pattern of changes in ERFE (P < 0.05) and hepcidin levels (P < 0.05), demonstrating the impact of accelerated erythropoiesis and not of other hypoxia-induced mechanisms. Compared with altitude alone, concurrent rHuEPO treatment and altitude exposure induced additive changes in hepcidin (P < 0.05) and ERFE (P ≤ 0.001) parallel with increases in hematocrit (P < 0.001), demonstrating a relevant range of both hepcidin and ERFE. A poor but significant correlation between hepcidin and ERFE was found (R2 = 0.13, P < 0.001). The findings demonstrate that hepcidin and ERFE are more rapid biomarkers of changes in iron demands than routine iron markers. Finally, ERFE and hepcidin may be sensitive markers in an antidoping context.


Asunto(s)
Mal de Altura/sangre , Altitud , Epoetina alfa/administración & dosificación , Eritropoyesis/efectos de los fármacos , Hematínicos/administración & dosificación , Hepcidinas/sangre , Hierro/sangre , Hormonas Peptídicas/sangre , Mal de Altura/diagnóstico , Biomarcadores/sangre , Dinamarca , Método Doble Ciego , Femenino , Homeostasis , Humanos , Inyecciones Intravenosas , Masculino , Proteínas Recombinantes/administración & dosificación , España , Factores de Tiempo
16.
Eur J Anaesthesiol ; 37(6): 482-490, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32175988

RESUMEN

BACKGROUND: Anaesthesia reduces mean arterial pressure (MAP), and to preserve organ perfusion, vasopressors are often used to maintain MAP above 60 mmHg. Cognitive dysfunction is common following major surgery and may relate to intra-operative cerebral hypoperfusion. OBJECTIVE: The aim of this study was to evaluate whether internal carotid artery (ICA) blood flow increases when MAP is kept higher than 60 mmHg using noradrenaline. DESIGN: A randomised, cross-over trial. SETTING: Department of Anaesthesia, Rigshospitalet, Copenhagen, Denmark, from December 2017 to April 2018. PATIENTS: Patients with median [IQR] age 71 [63 to 75] years underwent pancreaticoduodenectomy (n = 19), total pancreatic resection (n = 1) or gastro-entero anastomosis (n = 2) during combined propofol-remifentanil and thoracic epidural anaesthesia. INTERVENTION: MAP was maintained between 60 to 65, 70 to 75 and 80 to 85 mmHg, in a random order, by noradrenaline infusion at a stable level of anaesthesia. MAIN OUTCOME MEASURES: Primary outcome was change in ICA flow at MAP 60 to 65 vs. 80 to 85 mmHg. Secondary outcomes were change in ICA flow at MAP 60 to 65 vs. 70 to 75 and 70 to 75 vs. 80 to 85 mmHg. Duplex ultrasound evaluated ICA flow. RESULTS: A (mean ± SD) increase in MAP from 62 ±â€Š1 to 82 ±â€Š1 mmHg elevated ICA flow from 196 ±â€Š53 to 226 ±â€Š61 ml min (mean difference 31 ml min; 95% CI 19 to 42; P < 0.0001). An increase in MAP from 62 ±â€Š1 to 72 ±â€Š1 mmHg elevated ICA flow to 210 ±â€Š52 ml min (P = 0.0271) and ICA flow increased further (P = 0.0165) when MAP was elevated to 82 ±â€Š1 mmHg. CONCLUSION: During combined propofol-remifentanil and thoracic epidural anaesthesia, ICA flow increased by approximately 15% when the MAP was elevated from about 60 to 80 mmHg. Treatment of a reduction in MAP brought about by anaesthesia seems to enhance ICA flow. TRIAL REGISTRATION: Clinicaltrials.gov ID: NCT03309917.


Asunto(s)
Anestesia Epidural , Propofol , Anciano , Anestesia Epidural/efectos adversos , Presión Sanguínea , Arteria Carótida Interna , Estudios Cruzados , Humanos , Remifentanilo
17.
Int Heart J ; 61(3): 539-546, 2020 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-32350205

RESUMEN

In studies on left-sided valve disease, patients with combined lesions are generally excluded. We aimed to describe the clinical management and prognosis of patients with combined left-sided valve disease.From a single, tertiary care center, a total of 122 patients with combined left-sided valve disease of at least moderate severity were identified and compared with 143 controls with single-lesion valve disease (1VaD) of at least moderate severity. Endpoints were all-cause mortality and the combination of valve intervention and mortality.Overall survival for patients with two-lesion valve disease was significantly lower than that for patients with 1VaD (estimated 3-year survival: 52% versus 73%, P < 0.001). Compared with 1VaD, the combination of aortic stenosis and aortic regurgitation (AS/AR) was associated with a similar overall survival (hazard ratio (HR) (95% confidence interval (CI) ): 0.83 (0.47-1.48), P = 0.53), the combination of AR and mitral regurgitation (AR/MR) with an intermediate survival (HR (95% CI): 1.76 (1.03-3.00), P = 0.039) and the combination of AS and MR (AS/MR) with the poorest survival (HR (95% CI): 3.28 (2.16-4.98), P < 0.001). At 2.2 years of follow-up, the majority of patients in all three groups were either dead or had received valve intervention (AS/AR: 72%, AR/MR: 64%, and AS/MR: 80%).Combined valve disease was relatively rare but was associated with a decreased overall survival. Survival depended on the specific combination of valve lesions, with AS/MR carrying the worst prognosis. The majority of patients in all groups were either dead or had valve intervention performed within 2.2 years.


Asunto(s)
Enfermedades de las Válvulas Cardíacas/mortalidad , Anciano , Anciano de 80 o más Años , Dinamarca/epidemiología , Ecocardiografía , Femenino , Enfermedades de las Válvulas Cardíacas/diagnóstico , Enfermedades de las Válvulas Cardíacas/terapia , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Espera Vigilante
18.
Cogn Psychol ; 108: 42-71, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30593995

RESUMEN

In this paper, new evidence is presented for the assumption that the reason-relation reading of indicative conditionals ('if A, then C') reflects a conventional implicature. In four experiments, it is investigated whether relevance effects found for the probability assessment of indicative conditionals (Skovgaard-Olsen, Singmann, & Klauer, 2016a) can be classified as being produced by (a) a conversational implicature, (b) a (probabilistic) presupposition failure, or (c) a conventional implicature. After considering several alternative hypotheses, and the accumulating evidence from other studies as well, we conclude that the evidence is most consistent with the Relevance Effect being the outcome of a conventional implicature. This finding indicates that the reason-relation reading is part of the semantic content of indicative conditionals, albeit not part of their primary truth-conditional content.


Asunto(s)
Cognición , Comunicación , Lectura , Humanos
19.
N Engl J Med ; 373(21): 2015-24, 2015 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-26436963

RESUMEN

BACKGROUND: A finding of reduced aortic-valve leaflet motion was noted on computed tomography (CT) in a patient who had a stroke after transcatheter aortic-valve replacement (TAVR) during an ongoing clinical trial. This finding raised a concern about possible subclinical leaflet thrombosis and prompted further investigation. METHODS: We analyzed data obtained from 55 patients in a clinical trial of TAVR and from two single-center registries that included 132 patients who were undergoing either TAVR or surgical aortic-valve bioprosthesis implantation. We obtained four-dimensional, volume-rendered CT scans along with data on anticoagulation and clinical outcomes (including strokes and transient ischemic attacks [TIAs]). RESULTS: Reduced leaflet motion was noted on CT in 22 of 55 patients (40%) in the clinical trial and in 17 of 132 patients (13%) in the two registries. Reduced leaflet motion was detected among patients with multiple bioprosthesis types, including transcatheter and surgical bioprostheses. Therapeutic anticoagulation with warfarin, as compared with dual antiplatelet therapy, was associated with a decreased incidence of reduced leaflet motion (0% and 55%, respectively, P=0.01 in the clinical trial; and 0% and 29%, respectively, P=0.04 in the pooled registries). In patients who were reevaluated with follow-up CT, restoration of leaflet motion was noted in all 11 patients who were receiving anticoagulation and in 1 of 10 patients who were not receiving anticoagulation (P<0.001). There was no significant difference in the incidence of stroke or TIA between patients with reduced leaflet motion and those with normal leaflet motion in the clinical trial (2 of 22 patients and 0 of 33 patients, respectively; P=0.16), although in the pooled registries, a significant difference was detected (3 of 17 patients and 1 of 115 patients, respectively; P=0.007). CONCLUSIONS: Reduced aortic-valve leaflet motion was shown in patients with bioprosthetic aortic valves. The condition resolved with therapeutic anticoagulation. The effect of this finding on clinical outcomes including stroke needs further investigation. (Funded by St. Jude Medical and Cedars-Sinai Heart Institute; Portico-IDE ClinicalTrials.gov number, NCT02000115; SAVORY registry, NCT02426307; and RESOLVE registry, NCT02318342.).


Asunto(s)
Anticoagulantes/uso terapéutico , Válvula Aórtica/fisiopatología , Bioprótesis/efectos adversos , Enfermedades de las Válvulas Cardíacas/etiología , Prótesis Valvulares Cardíacas/efectos adversos , Trombosis/etiología , Anciano , Anciano de 80 o más Años , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Femenino , Tomografía Computarizada Cuatridimensional , Humanos , Ataque Isquémico Transitorio/etiología , Masculino , Sistema de Registros , Accidente Cerebrovascular/etiología
20.
Undersea Hyperb Med ; 45(3): 335-350, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30028920

RESUMEN

PURPOSE: Experiments have shown that hyperbaric oxygen (HBO2) therapy reduces cyanide-induced cerebral distress. The exact mechanism behind HBO2's neuroprotective effect is unknown, but has been proposed to be mediated by an increased neuronal nitric oxide (NO) bioavailability, which may compete with cyanide for the active site of cytochrome oxidase in the mitochondrial respiratory chain. We hypothesized that the ameliorating effect of HBO2 is caused by an increased bioavailability of NO, which can be attenuated by injection of the selective neuronal NO synthase inhibitor, 7-nitroindazole, preceding the HBO2 procedure. METHODS: A total of 41 anesthetized female Sprague-Dawley rats were allocated to four groups: 1) vehicle [1.2 ml isotonic NaCl via intra-arterial administration]; 2) cyanide [5.4 mg/kg potassium CN (KCN) intra-arterial] plus 7-nitroindazole [25 mg/kg 7-nitroindazole via intraperitoneal injection]; 3) cyanide plus 7-nitroindazole plus HBO2 [284 kPa for 90 minutes]; 4) cyanide plus 7-nitroindazole plus normobaric oxygen [101.3 kPa for 90 minutes]. Cerebral interstitial lactate, glucose, glycerol and pyruvate were evaluated by means of microdialysis. RESULTS: HBO2 during inhibition of nNOS worsened cerebral metabolism compared to both solely CN-intoxicated animals and normobaric oxygen-treated animals. This was indicated by elevated lactate (in mM; 0.85 vs. 0.63 and 0.42, P=0.006 and P ⟨ 0.001, respectively), glycerol (in mM; 46 vs. 17 and 14, both P ⟨ 0.001), glucose (in mM; 0.58 vs. 0.31 and 0.32, both P ⟨ 0.001). CONCLUSIONS: The results indicate that a specific nNOS inhibition offsets the ameliorating effect of HBO2 during cerebral CN intoxication. However, other factors might contribute to this neuroprotective effect as well.


Asunto(s)
Encefalopatías/metabolismo , Encéfalo/metabolismo , Cianuros/envenenamiento , Oxigenoterapia Hiperbárica , Óxido Nítrico Sintasa de Tipo I/antagonistas & inhibidores , Animales , Encefalopatías/inducido químicamente , Encefalopatías/terapia , Inhibidores Enzimáticos/farmacología , Femenino , Glucosa/metabolismo , Glicerol/metabolismo , Indazoles/farmacología , Ácido Láctico/metabolismo , Óxido Nítrico Sintasa de Tipo I/metabolismo , Oxígeno/administración & dosificación , Oxígeno/metabolismo , Presión Parcial , Ácido Pirúvico/metabolismo , Ratas , Ratas Sprague-Dawley
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