Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 71
Filtrar
1.
Int J Mol Sci ; 24(7)2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-37047476

RESUMEN

Lupin is a high-protein legume crop that grows in a wide range of edaphoclimatic conditions where other crops are not viable. Its unique seed nutrient profile can promote health benefits, and it has been proposed as a phytoremediation plant. Most rhizobia nodulating Lupinus species belong to the genus Bradyrhizobium, comprising strains that are phylogenetically related to B. cytisi, B. hipponenese, B. rifense, B. iriomotense/B. stylosanthis, B. diazoefficiens, B. japonicum, B. canariense/B. lupini, and B. retamae/B. valentinum. Lupins are also nodulated by fast-growing bacteria within the genera Microvirga, Ochrobactrum, Devosia, Phyllobacterium, Agrobacterium, Rhizobium, and Neorhizobium. Phylogenetic analyses of the nod and nif genes, involved in microbial colonization and symbiotic nitrogen fixation, respectively, suggest that fast-growing lupin-nodulating bacteria have acquired their symbiotic genes from rhizobial genera other than Bradyrhizobium. Horizontal transfer represents a key mechanism allowing lupin to form symbioses with bacteria that were previously considered as non-symbiotic or unable to nodulate lupin, which might favor lupin's adaptation to specific habitats. The characterization of yet-unstudied Lupinus species, including microsymbiont whole genome analyses, will most likely expand and modify the current lupin microsymbiont taxonomy, and provide additional knowledge that might help to further increase lupin's adaptability to marginal soils and climates.


Asunto(s)
Bradyrhizobium , Fabaceae , Lupinus , Rhizobium , Fabaceae/genética , Fabaceae/microbiología , Lupinus/genética , Lupinus/microbiología , Nódulos de las Raíces de las Plantas/microbiología , Filogenia , Transferencia de Gen Horizontal , Promoción de la Salud , ADN Bacteriano/genética , Verduras/genética , Rhizobium/genética , Bradyrhizobium/genética , Simbiosis/genética , Análisis de Secuencia de ADN , ARN Ribosómico 16S/genética
3.
J Am Soc Echocardiogr ; 37(5): 486-494, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38354759

RESUMEN

BACKGROUND: Cardiac magnetic resonance (CMR) was recently reported to predict mean pulmonary capillary wedge pressure (PCWP). However, there is a paucity of data on its accuracy for estimation of PCWP in patients with normal left ventricular (LV) ejection fraction (EF). We sought to examine its accuracy against the invasive gold standard and to compare it with the accuracy of comprehensive echocardiography. METHODS: Stable patients with EF of ≥50% who underwent right heart catheterization, CMR, and echocardiographic imaging within 1 week were included. Pulmonary capillary wedge pressure was estimated by CMR using a previously validated equation where PCWP is estimated based on the left atrial maximum volume and LV mass. Echocardiographic estimation of PCWP was based on 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines, taking into account the presence of myocardial disease. RESULTS: The mean age of the 79 patients was 55 ± 15 years, and 58.2% were female. There were 33 patients with PCWP >15 mm Hg by right heart catheterization. Cardiac magnetic resonance prediction of PCWP had an area under the curve (AUC) = 0.72. In comparison, echocardiographic prediction of PCWP showed a higher accuracy (AUC = 0.87 vs AUC = 0.72; P = .008). CONCLUSIONS: In patients with normal LV EF, CMR estimation of mean PCWP based on LV mass and left atrial volume has modest accuracy for detecting patients with mean PCWP >15 mm Hg. Comprehensive echocardiography predicts elevated PCWP with higher accuracy in comparison with CMR.


Asunto(s)
Ecocardiografía , Imagen por Resonancia Cinemagnética , Presión Esfenoidal Pulmonar , Volumen Sistólico , Función Ventricular Izquierda , Humanos , Femenino , Masculino , Volumen Sistólico/fisiología , Persona de Mediana Edad , Presión Esfenoidal Pulmonar/fisiología , Imagen por Resonancia Cinemagnética/métodos , Ecocardiografía/métodos , Función Ventricular Izquierda/fisiología , Cateterismo Cardíaco/métodos , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Estudios Retrospectivos , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Anciano
4.
Pacing Clin Electrophysiol ; 36(7): 830-6, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23510001

RESUMEN

BACKGROUND: Inappropriate sinus tachycardia (IST) is characterized by persistent and disproportional elevation of heart rate (HR). Ivabradine has been successfully used in some patients. METHODS: Twenty-four patients (18 women, 41 ± 13 year olds) were diagnosed with IST according to current guidelines criteria. Patients were treated with 5-7.5 mg of ivabradine twice a day. Twenty-four-hour Holter recordings and the SF-36 Health Survey were performed at 6 months to evaluate both HR control and clinical status. RESULTS: Holter recordings before and after 6 months on treatment showed a significant reduction in the average maximal HR of 155 ± 18 beats/min versus 132 ± 16 beats/min, mean HR of 97 ± 6 beats/min versus 79 ± 8 beats/min (mean daytime HR of 103 ± 8 beats/min vs 84 ± 10 beats/min) and minimal HR of 58 ± 12 beats/min versus 48 ± 7 beats/min (Wilcoxon analysis, P < 0.05). The SF-36 mean score showed a significant improvement on ivabradine treatment (57 ± 23 vs 76 ± 20), with a better physical and mental status scores (56 ± 25 vs 74 ± 22 and 58 ± 24 vs 78 ± 18, respectively) (Wilcoxon analysis, P < 0.001). Mean dose of ivabradine was 5.8 ± 1.4 mg. No episodes of severe bradycardia or syncope were reported. After 1 year, patients were asked to stop treatment to reevaluate the situation. Twenty patients were on treatment and only 10 patients accepted to stop ivabradine. Only two patients (20%) remained on IST criteria. CONCLUSIONS: IST patients treated with ivabradine showed both HR normalization and quality-of-life improvement maintained in the long-term follow-up. Stopping ivabradine after 1 year unexpectedly showed that HR remained in the normal limits in 80% of the patients.


Asunto(s)
Benzazepinas/uso terapéutico , Satisfacción del Paciente , Calidad de Vida , Taquicardia Sinusal/diagnóstico , Taquicardia Sinusal/tratamiento farmacológico , Adulto , Cardiotónicos/uso terapéutico , Femenino , Humanos , Ivabradina , Estudios Longitudinales , Masculino , Resultado del Tratamiento
5.
Plants (Basel) ; 12(24)2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38140436

RESUMEN

Nodule endophytes and associated bacteria are non-symbiotic bacteria that colonize legume nodules. They accompany nodulating rhizobia and can form beneficial associations, as some of them are plant growth-promoting rhizobacteria (PGPR) that are able to promote germination and plant growth and increase tolerance to biotic and abiotic stress. White lupin (Lupinus albus) is a legume crop that is gaining relevance as a suitable alternative to soybean as a plant protein source. Eleven nodule-associated bacteria were isolated from white lupin nodules grown in a Tunisian soil. They belonged to the genera Rhizobium, Ensifer, Pseudomonas and Bacillus. Their plant growth-promoting (PGP) and enzymatic activities were tested in vitro. Strains Pseudomonas sp., L1 and L12, displayed most PGP activities tested, and were selected for in planta assays. Inoculation with strains L1 or L12 increased seed germination and had the same positive effects on all plant growth parameters as did inoculation with symbiotic Bradyrhizobium canariense, with no significant differences among treatments. Inoculation with efficient nitrogen-fixing rhizobia must compete with rhizobia present in the soil that sometimes nodulate efficiently but fix nitrogen poorly, leading to a low response to inoculation. In such cases, inoculation with highly effective PGPR might represent a feasible alternative to boost crop productivity.

6.
Plants (Basel) ; 12(23)2023 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-38068608

RESUMEN

Agricultural soil salinization, which is often combined with heavy-metal contamination, is an ever-growing problem in the current era of global change. Legumes have a high potential for nitrogen fixation and are ideal crops for the reclamation of degraded soils. Alfalfa (Medicago sativa) is a valuable forage crop cultivated worldwide. Alfalfa plants fertilized with nitrogen or inoculated with a salt- and cadmium-tolerant Sinorhizobium meliloti strain were subjected to combined NaCl and CdCl2 stresses. Our results showed that inoculated plants presented higher aerial biomass than nitrogen-fertilized plants when they were exposed to salinity and cadmium together. To assess the mechanisms involved in the plant response to the combined stresses, superoxide dismutase and catalase antioxidant enzymatic activities were determined. Both increased upon stress; however, the increase in catalase activity was significantly less marked for inoculated plants, suggesting that other tolerance mechanisms might be active. Cd accumulation was lower in inoculated plants than in fertilized plants, which appears to imply that inoculation somehow prevented cadmium uptake by the plant roots. Expression analyses of several involved genes suggested that inoculation stimulated the biosynthesis of proline, phytochelatins, and homophytochelatins, together indicating that inoculated plants might be better suited to withstand combined salinity and cadmium stress effects.

7.
Appl Microbiol Biotechnol ; 96(2): 543-54, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22246528

RESUMEN

A survey of symbiotic bacteria from legumes grown in high mercury-contaminated soils (Almadén, Spain) was performed to produce a collection of rhizobia which could be well adapted to the environmental conditions of this region and be used for restoration practices. Nineteen Hg-tolerant rhizobia were isolated from nodules of 11 legume species (of the genera Medicago, Trifolium, Vicia, Lupinus, Phaseolus, and Retama) and characterized. Based on their growth on Hg-supplemented media, the isolates were classified into three susceptibility groups. The minimum inhibitory concentrations (MICs) and the effective concentrations that produce 50% mortality identified the patterns of mercury tolerance and showed that 15 isolates were tolerant. The dynamics of cell growth during incubation with mercury showed that five isolates were unaffected by exposure to Hg concentrations under the MICs. Genetic analyses of the 16S rRNA gene assigned ten strains to Rhizobium leguminosarum, six to Ensifer medicae, two to Bradyrhizobium canariense, and one to Rhizobium radiobacter. Inoculation of host plants and analysis of the nodC genes revealed that most of them were symbiotically effective. Finally, three isolates were selected for bioremediation processes with restoration purposes on the basis of their levels of Hg tolerance, their response to high concentrations of this heavy metal, and their genetic affiliation and nodulation capacity.


Asunto(s)
Bacterias/aislamiento & purificación , Fabaceae/crecimiento & desarrollo , Mercurio/metabolismo , Nódulos de las Raíces de las Plantas/microbiología , Contaminantes del Suelo/metabolismo , Bacterias/clasificación , Bacterias/genética , Bacterias/metabolismo , Fabaceae/microbiología , Datos de Secuencia Molecular , Filogenia , Nódulos de las Raíces de las Plantas/crecimiento & desarrollo , Microbiología del Suelo
8.
JACC Cardiovasc Imaging ; 15(10): 1730-1741, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35842362

RESUMEN

BACKGROUND: Grading of aortic regurgitation (AR) and mitral regurgitation (MR) is similar in the cardiology guidelines despite distinct differences in left ventricular (LV) adaptive pathophysiology. OBJECTIVES: This study compared differences in LV remodeling in patients with similar degrees of AR and MR severity and evaluated optimal cutoffs for significant AR in relation to the outcome of aortic valve replacement or repair (AVR) during follow-up. METHODS: From 2008 to 2018, consecutive patients with isolated AR or MR who had cardiac magnetic resonance (CMR) were identified and CMR parameters were compared. Patients with left ventricular ejection fraction (LVEF) <50%, ischemic scar >5%, valve stenosis, or concomitant regurgitation were excluded. Patients were followed longitudinally for AVR. RESULTS: Baseline characteristics of isolated AR (n = 418) and isolated MR (n = 1,073) were comparable except for higher male proportion and hypertension in AR, while heart failure was more prevalent in MR. Indexed LV end-diastolic and end-systolic volumes and mass were higher in AR compared with MR at the same level of regurgitant fraction. During follow-up (mean 2.1 years), 18.7% of AR patients underwent AVR based on symptoms or LV remodeling. Interestingly, 38.0% of patients that underwent AVR within 3 months after CMR did not meet severe AVR by current guidelines of AR severity. AR regurgitant fraction>35% had high sensitivity (86%) and specificity (88%) for identifying patients who underwent AVR. CONCLUSIONS: For similar regurgitation severity, LV remodeling is different in AR compared with MR. Cardiac symptoms and significant LV remodeling in AR requiring AVR occur frequently in patients with less severity than currently proposed. The study findings suggest that the optimal threshold for severe AR with CMR is different than MR and is lower than currently stated in the guidelines.


Asunto(s)
Insuficiencia de la Válvula Aórtica , Enfermedades de las Válvulas Cardíacas , Implantación de Prótesis de Válvulas Cardíacas , Insuficiencia de la Válvula Mitral , Disfunción Ventricular Izquierda , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Insuficiencia de la Válvula Aórtica/etiología , Humanos , Masculino , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Volumen Sistólico , Función Ventricular Izquierda , Remodelación Ventricular
9.
Heart Fail Rev ; 16(4): 339-49, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21161681

RESUMEN

The evaluation of ischemic heart disease is the cornerstone of clinical Cardiology. Although there are many means of ischemic evaluation, all are with their own limitations. While perfusion-based studies are highly sensitive, they lack specificity. Conversely, systolic wall motion analysis with echocardiography tends to have high specificity; however, the sensitivity may be limited by short duration of systolic abnormalities when present. With the advent of Doppler echocardiography, and more specifically tissue Doppler imaging, and strain and strain rate imaging, a more comprehensive evaluation of the left ventricular function is available, including diastole. Diastolic abnormalities in the setting of ischemia are now being studied using these new parameters and have been suggested as a reliable marker of ischemia. Exercise-induced abnormalities in diastolic parameters have improved sensitivities and specificities over traditional stress testing and persist longer than systolic abnormalities. A review of the medical literature regarding the subject will be discussed here.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico , Ecocardiografía de Estrés , Isquemia Miocárdica/diagnóstico , Imagen de Perfusión Miocárdica/instrumentación , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/patología , Diástole , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/patología , Humanos , Imagen por Resonancia Magnética , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/patología , Tomografía Computarizada de Emisión de Fotón Único
10.
J Am Coll Cardiol ; 77(5): 609-619, 2021 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-33538259

RESUMEN

Coenzyme Q10 (CoQ10) is a naturally occurring compound that is found in animals and all humans. It has a fundamental role in cellular energy production. Although it is produced in the body, tissue deficiency can occur due to medications such as statins, which inhibit the mevalonate pathway. The clinical syndromes of statin-associated muscle symptoms (SAMS) and some of the features observed in patients with heart failure (HF) may be related to blood and tissue deficiency of CoQ10. Numerous clinical trials of CoQ10 in SAMS have yielded conflicting results. Yet, the weight of evidence as reflected in meta-analyses supports the use of exogenous CoQ10 in SAMS. In patients with HF, large-scale randomized clinical trials are lacking, although one relatively contemporary trial, Q-SYMBIO, suggests an adjunctive role for CoQ10. The possibility that statin-related CoQ10 deficiency may play a role in patients with diastolic HF is an intriguing hypothesis that warrants further exploration.


Asunto(s)
Ataxia/tratamiento farmacológico , Enfermedades Cardiovasculares/prevención & control , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Enfermedades Mitocondriales/tratamiento farmacológico , Debilidad Muscular/tratamiento farmacológico , Ubiquinona/análogos & derivados , Ubiquinona/deficiencia , Suplementos Dietéticos , Humanos , Ubiquinona/uso terapéutico
11.
Front Plant Sci ; 12: 810692, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35069669

RESUMEN

Almost half of the world's agricultural soils are acidic, and most of them present significant levels of aluminum (Al) contamination, with Al3+ as the prevailing phytotoxic species. Lupin is a protein crop that is considered as an optimal alternative to soybean cultivation in cold climates. Lupins establish symbiosis with certain soil bacteria, collectively known as rhizobia, which are capable of fixing atmospheric nitrogen. Moreover, some lupin species, especially white lupin, form cluster roots, bottlebrush-like structures specialized in the mobilization and uptake of nutrients in poor soils. Cluster roots are also induced by Al toxicity. They exude phenolic compounds and organic acids that chelate Al to form non-phytotoxic complexes in the rhizosphere and inside the root cells, where Al complexes are accumulated in the vacuole. Lupins flourish in highly acidic soils where most crops, including other legumes, are unable to grow. Some lupin response mechanisms to Al toxicity are common to other plants, but lupin presents specific tolerance mechanisms, partly as a result of the formation of cluster roots. Al-induced lupin organic acid secretion differs from P-induced secretion, and organic acid transporters functions differ from those in other legumes. Additionally, symbiotic rhizobia can contribute to Al detoxification. After revising the existing knowledge on lupin distinct Al tolerance mechanisms, we conclude that further research is required to elucidate the specific organic acid secretion and Al accumulation mechanisms in this unique legume, but definitely, white lupin arises as a choice crop for cultivation in Al-rich acidic soils in temperate climate regions.

12.
Front Plant Sci ; 12: 644218, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33747024

RESUMEN

Nitrogen (N) and phosphorus (P) are two major plant nutrients, and their deficiencies often limit plant growth and crop yield. The uptakes of N or P affect each other, and consequently, understanding N-P interactions is fundamental. Their signaling mechanisms have been studied mostly separately, and integrating N-P interactive regulation is becoming the aim of some recent works. Lupins are singular plants, as, under N and P deficiencies, they are capable to develop new organs, the N2-fixing symbiotic nodules, and some species can also transform their root architecture to form cluster roots, hundreds of short rootlets that alter their metabolism to induce a high-affinity P transport system and enhance synthesis and secretion of organic acids, flavonoids, proteases, acid phosphatases, and proton efflux. These modifications lead to mobilization in the soil of, otherwise unavailable, P. White lupin (Lupinus albus) represents a model plant to study cluster roots and for understanding plant acclimation to nutrient deficiency. It tolerates simultaneous P and N deficiencies and also enhances uptake of additional nutrients. Here, we present the structural and functional modifications that occur in conditions of P and N deficiencies and lead to the organogenesis and altered metabolism of nodules and cluster roots. Some known N and P signaling mechanisms include different factors, including phytohormones and miRNAs. The combination of the individual N and P mechanisms uncovers interactive regulation pathways that concur in nodules and cluster roots. L. albus interlinks N and P recycling processes both in the plant itself and in nature.

13.
JACC Cardiovasc Imaging ; 14(3): 573-584, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33129724

RESUMEN

OBJECTIVES: This study hypothesized that left ventricular (LV) enlargement in Barlow disease can be explained by accounting for the total volume load that consists of transvalvular mitral regurgitation (MR) and the prolapse volume. BACKGROUND: Barlow disease is characterized by long prolapsing mitral leaflets that can harbor a significant amount of blood-the prolapse volume-at end-systole. The LV in Barlow disease can be disproportionately enlarged relative to MR severity, leading to speculation of Barlow cardiomyopathy. METHODS: Cardiac magnetic resonance (CMR) was used to compare MR, prolapse volume, and heart chambers remodeling in patients with Barlow disease (bileaflet prolapse [BLP]) and in single leaflet prolapse (SLP). RESULTS: A total of 157 patients (81 with BLP, 76 with SLP) were included. Patients with SLP were older and more had hypertension. Patients with BLP had more heart failure. Indexed LV end-diastolic volume was larger in BLP despite similar transvalvular MR. However, the prolapse volume was larger in BLP, which led to larger total volume load compared with SLP. Increasing tertiles of prolapse volume and MR both led to an incremental increase in LV end-diastolic volume in BLP. Using the total volume load improved the correlation with indexed LV end-diastolic volume in the BLP group, which closely matched that of SLP. A multivariable model that incorporated the prolapse volume explained left heart chamber enlargement better than a MR-based model, independent of prolapse category. CONCLUSIONS: The prolapse volume is part of the total volume load exerted on the LV during the cardiac cycle and could help explain the disproportionate LV enlargement relative to MR severity noted in Barlow disease.


Asunto(s)
Insuficiencia de la Válvula Mitral , Prolapso de la Válvula Mitral , Ventrículos Cardíacos , Humanos , Espectroscopía de Resonancia Magnética , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/etiología , Prolapso de la Válvula Mitral/diagnóstico por imagen , Valor Predictivo de las Pruebas
14.
JACC Cardiovasc Imaging ; 14(6): 1146-1160, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33341409

RESUMEN

OBJECTIVES: This study used cardiovascular magnetic resonance (CMR) to evaluate whether elevated extracellular volume (ECV) was associated with mitral valve prolapse (MVP) or if elevated ECV was a consequence of remodeling independent of primary mitral regurgitation (MR) etiology. BACKGROUND: Replacement fibrosis in primary MR is more prevalent in MVP; however, data on ECV as a surrogate for diffuse interstitial fibrosis in primary MR are limited. METHODS: Patients with chronic primary MR underwent comprehensive CMR phenotyping and were stratified into an MVP cohort (>2 mm leaflet displacement on a 3-chamber cine CMR) and a non-MVP cohort. Factors associated with ECV and replacement fibrosis were assessed. The association of ECV and symptoms related to MR and clinical events (mitral surgery and cardiovascular death) was ascertained. RESULTS: A total of 424 patients with primary MR (229 with MVP and 195 non-MVP) were enrolled. Replacement fibrosis was more prevalent in the MVP cohort (34.1% vs. 6.7%; p < 0.001), with bi-leaflet MVP having the strongest association with replacement fibrosis (odds ratio: 10.5; p < 0.001). ECV increased with MR severity in a similar fashion for both MVP and non-MVP cohorts and was associated with MR severity but not MVP on multivariable analysis. Elevated ECV was independently associated with symptoms related to MR and clinical events. CONCLUSIONS: Although replacement fibrosis was more prevalent in MVP, diffuse interstitial fibrosis as inferred by ECV was associated with MR severity, regardless of primary MR etiology. ECV was independently associated with symptoms related to MR and clinical events. (DeBakey Cardiovascular Magnetic Resonance Study [DEBAKEY-CMR]; NCT04281823).


Asunto(s)
Insuficiencia de la Válvula Mitral , Humanos , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/cirugía , Valor Predictivo de las Pruebas
15.
J Am Coll Cardiol ; 76(11): 1291-1301, 2020 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-32912443

RESUMEN

BACKGROUND: Quantitation of tricuspid regurgitant (TR) severity can be challenging with conventional echocardiographic imaging and may be better evaluated using cardiovascular magnetic resonance (CMR). OBJECTIVES: In patients with functional TR, this study sought to examine the relationship between TR volume (TRVol) and TR fraction (TRF) with all-cause mortality. METHODS: We examined 547 patients with functional TR using CMR to quantify TRVol and TRF. The primary outcome was all-cause mortality. Thresholds for mild, moderate, and severe TR were derived based on natural history outcome data. RESULTS: During a median follow-up of 2.6 years (interquartile range: 1.7 to 3.3 years), there were 93 deaths, with an estimated 5-year survival of 79% (95% confidence interval [CI]: 73% to 83%). After adjustment of clinical and imaging variables, including RV function, both TRF (adjusted hazard ratio [AHR] per 10% increment: 1.26; 95% CI: 1.10 to 1.45; p = 0.001) and TRVol (AHR per 10-ml increment: 1.15; 95% CI: 1.04 to 1.26; p = 0.004) were associated with mortality. Patients in the highest-risk strata of TRVol ≥45 ml or TRF ≥50% had the worst prognosis (AHR: 2.26; 95% CI: 1.36 to 3.76; p = 0.002 for TRVol and AHR: 2.60; 95% CI: 1.45 to 4.66; p = 0.001 for TRF). CONCLUSIONS: This is the first study to use CMR to assess independent prognostic implications of functional TR. Both TRF and TRVol were associated with increased mortality after adjustment for clinical and imaging covariates, including right ventricular ejection fraction. A TRVol of ≥45 ml or TRF of ≥50% identified patients in the highest-risk strata for mortality. These CMR thresholds should be used for patient selection in future trials to determine if tricuspid valve intervention improves outcomes in this high-risk group.


Asunto(s)
Imagen por Resonancia Cinemagnética/tendencias , Insuficiencia de la Válvula Tricúspide/diagnóstico por imagen , Insuficiencia de la Válvula Tricúspide/mortalidad , Anciano , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Mortalidad/tendencias , Estudios Prospectivos , Insuficiencia de la Válvula Tricúspide/fisiopatología
17.
J Am Coll Cardiol ; 72(8): 823-834, 2018 08 21.
Artículo en Inglés | MEDLINE | ID: mdl-30115220

RESUMEN

BACKGROUND: Recent studies reported left ventricular (LV) fibrosis in patients with primary mitral regurgitation (MR) thought to be principally due to mitral valve prolapse (MVP). OBJECTIVES: This study sought to evaluate the prevalence, characteristics, and prognostic implications of LV fibrosis in a large cohort of primary MR patients with and without MVP using cardiovascular magnetic resonance (CMR). METHODS: Patients referred for contrast CMR assessment of chronic primary MR were enrolled and underwent comprehensive assessment of cardiac remodeling, severity of MR, and LV replacement fibrosis. Primary MR patients were stratified into: an MVP group if there was >2 mm mitral leaflet displacement on cine-CMR, or a non-MVP group. Patients were followed for arrhythmic events (sudden cardiac death, aborted sudden cardiac arrest, and sustained or inducible ventricular arrhythmia). RESULTS: A total of 356 primary MR patients (177 MVP and 179 non-MVP) were enrolled. LV fibrosis was more prevalent in the MVP group than the non-MVP group (36.7% vs. 6.7%; p < 0.001). The presence of MVP had the strongest association (odds ratio: 6.82; p < 0.001) with LV fibrosis even after adjustment for clinical variables, measures of cardiac remodeling, and MR severity. During follow-up (median 1,354 days), MVP patients with LV fibrosis had the highest event rate for arrhythmic events. CONCLUSIONS: In primary MR patients, LV fibrosis is more prevalent in MVP than non-MVP, suggesting a unique pathophysiology beyond volume overload in MVP. LV fibrosis in primary MR may represent a risk marker of arrhythmic events.


Asunto(s)
Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/epidemiología , Prolapso de la Válvula Mitral/diagnóstico por imagen , Prolapso de la Válvula Mitral/epidemiología , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/epidemiología , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Fibrosis/diagnóstico por imagen , Fibrosis/epidemiología , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
18.
J Appl Psychol ; 92(1): 239-49, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17227165

RESUMEN

This study identifies stigma as a potential precursor to self-fulfilling prophecies in training interactions. Expectations held by leaders often result in actions that elicit expectancy-confirming behaviors from their subordinates. The results of the present study suggest that trainee weight (manipulated with a photograph depicting the trainee as either obese or average weight for height) influenced female trainer expectations and evaluations of the training and trainee. Furthermore, the results suggest that negative expectations held by trainers were related to trainee evaluations of the training and the trainer and, for less flexible trainers, to decrements in trainee performance on the trained task. Overall, the results suggest that trainer expectations can be influenced by stereotypes held about trainee characteristics, thus undermining training effectiveness.


Asunto(s)
Actitud , Obesidad/psicología , Autoeficacia , Estereotipo , Enseñanza , Adulto , Femenino , Humanos , Masculino , Encuestas y Cuestionarios
19.
Circulation ; 111(5): 682-96, 2005 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-15687114

RESUMEN

Cardiovascular disease is the leading cause of mortality for women in the United States. Coronary heart disease, which includes coronary atherosclerotic disease, myocardial infarction, acute coronary syndromes, and angina, is the largest subset of this mortality, with >240,000 women dying annually from the disease. Atherosclerotic coronary artery disease (CAD) is the focus of this consensus statement. Research continues to report underrecognition and underdiagnosis of CAD as contributory to high mortality rates in women. Timely and accurate diagnosis can significantly reduce CAD mortality for women; indeed, once the diagnosis is made, it does appear that current treatments are equally effective at reducing risk in both women and men. As such, noninvasive diagnostic and prognostic testing offers the potential to identify women at increased CAD risk as the basis for instituting preventive and therapeutic interventions. Nevertheless, the recent evidence-based practice program report from the Agency for Healthcare Research and Quality noted the paucity of women enrolled in diagnostic research studies. Consequently, much of the evidence supporting contemporary recommendations for noninvasive diagnostic studies in women is extrapolated from studies conducted predominantly in cohorts of middle-aged men. The majority of diagnostic and prognostic evidence in cardiac imaging in women and men has been derived from observational registries and referral populations that are affected by selection and other biases. Thus, a better understanding of the potential impact of sex differences on noninvasive cardiac testing in women may greatly improve clinical decision making. This consensus statement provides a synopsis of available evidence on the role of the exercise ECG and cardiac imaging modalities, both those in common use as well as developing technologies that may add clinical value to the diagnosis and risk assessment of the symptomatic and asymptomatic woman with suspected CAD.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Ecocardiografía de Estrés , Electrocardiografía , Prueba de Esfuerzo , Femenino , Humanos , Imagen por Resonancia Magnética , Pronóstico , Derivación y Consulta , Medición de Riesgo , Factores Sexuales , Tomografía Computarizada de Emisión de Fotón Único , Tomografía Computarizada por Rayos X
20.
J Am Coll Cardiol ; 45(8): 1223-6, 2005 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-15837253

RESUMEN

OBJECTIVES: This study was designed to determine how novel indexes of left ventricular (LV) filling pressure-transmitral early diastolic velocity/tissue Doppler mitral annular early diastolic velocity (E/Ea) and B-type natriuretic peptide (BNP)-compare to conventional predictors of outcome in patients with congestive heart failure (CHF). BACKGROUND: It is known that E/Ea can predict LV filling pressure in patients with cardiac disease, including, in contrast to conventional Doppler indexes, in normal ejection fraction. B-type natriuretic peptide has also been correlated to LV filling pressure, but appears to provide more global cardiac information than E/Ea. It is unknown, however, how these novel indexes compare to conventional predictors of CHF patient outcome. METHODS: A total of 116 consecutive patients hospitalized with CHF underwent simultaneous clinical assessment, BNP, and comprehensive echo-Doppler study once ready for discharge. The ability of these variables to determine the primary end point (cardiac death or re-hospitalization for CHF) was determined. RESULTS: Follow-up was complete on 110 of 116 patients at a mean of 527 days after hospital discharge. There were 54 patients (50%) with the primary end point (37 re-hospitalizations for CHF and 17 cardiac deaths). On Cox univariate analysis, E/Ea (chi-square = 13.6, p = 0.0001) and BNP (chi-square = 17.0, p < 0.0001) were significant predictors of the primary end point. In stepwise analysis, BNP >/=250 pg/ml and mitral E/Ea >/=15 had incremental predictive power (chi-square = 23.1, p for increment = 0.02), to which conventional predictors did not add further prognostic information. CONCLUSIONS: In patients admitted to hospital with CHF, pre-discharge BNP and E/Ea are incremental predictors of outcome, to which conventional predictors do not significantly add.


Asunto(s)
Ecocardiografía Doppler , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/mortalidad , Péptido Natriurético Encefálico/análisis , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Volumen Sistólico/fisiología , Función Ventricular Izquierda/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA