RESUMEN
UNLABELLED: Left atrial (LA) distension has been demonstrated to be linked with aortic stiffness in different patient populations. Three-dimensional (3D) speckle-tracking echocardiography (STE) seems to be a promising tool for volumetric and functional evaluation of the LA. The aim of the present study was to determine whether correlations exist between 3DSTE-derived LA volume-based and strain parameters characterizing all phasic functions of the LA and echocardiographic aortic elastic properties in healthy subjects. The study included 19 healthy volunteers (mean age: 37.9 ± 11.4 years, 11 men) who had undergone complete two-dimensional (2D) Doppler transthoracic echocardiography extended with the assessment of aortic elastic properties and 3DSTE. RESULTS: None of LA volumes correlated with echocardiographic aortic elastic properties. Active atrial stroke volume correlated with aortic stiffness index (ASI, r = 0.45, p = 0.05). None of other volume-based functional properties significantly correlated with aortic stiffness parameters. Global peak 3D strain correlated with aortic strain (r = â0.46, p = 0.05). global radial pre-atrial contraction strain correlated with ASI (r = â0.49, p = 0.04) and AS (r = â0.50, p = 0.04). CONCLUSIONS: Correlations exist between 3DSTE-derived LA functional parameters and eschocardiographic aortic elastic properties in healthy subjects.
Asunto(s)
Aorta/diagnóstico por imagen , Función del Atrio Izquierdo , Ecocardiografía Tridimensional , Atrios Cardíacos/diagnóstico por imagen , Rigidez Vascular , Adulto , Fenómenos Biomecánicos , Ecocardiografía Doppler , Elasticidad , Femenino , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Función Ventricular IzquierdaRESUMEN
New-onset diabetes after transplantation (NODAT) is one of the frequent complications following kidney transplantation. Patients were randomized to receive cyclosporine A- or tacrolimus-based immunosuppression. Fasting and oral glucose tolerance tests were performed, and the patients were assigned to one of the following three groups based on the results: normal, impaired fasting glucose/impaired glucose tolerance (IFG/IGT), or NODAT. NODAT developed in 14% of patients receiving cyclosporine A-based immunosuppression and in 26% of patients taking tacrolimus (p = 0.0002). Albumin levels were similar, but uric acid level (p = 0.002) and the age of the recipient (p = 0.003) were significantly different comparing the diabetic and the normal groups. Evaluation of tissue samples revealed that acute cellular rejection (ACR) and interstitial fibrosis/tubular atrophy (IF/TA) were significantly different in the NODAT group. The pathological effect of new-onset diabetes after kidney transplantation can be detected in the morphology of the renal allograft earlier, before the development of any sign of functional impairment.
Asunto(s)
Inhibidores de la Calcineurina , Ciclosporina/efectos adversos , Diabetes Mellitus/inducido químicamente , Inmunosupresores/efectos adversos , Trasplante de Riñón/efectos adversos , Tacrolimus/efectos adversos , Adulto , Factores de Edad , Anciano , Atrofia , Biopsia , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Calcineurina/metabolismo , Diabetes Mellitus/sangre , Diabetes Mellitus/epidemiología , Diabetes Mellitus/metabolismo , Ayuno/sangre , Femenino , Fibrosis , Prueba de Tolerancia a la Glucosa , Rechazo de Injerto/inmunología , Rechazo de Injerto/patología , Rechazo de Injerto/prevención & control , Humanos , Hungría/epidemiología , Incidencia , Riñón/efectos de los fármacos , Riñón/inmunología , Riñón/patología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Factores de TiempoRESUMEN
The incidence of post-transplant diabetes mellitus and its effects on the kidney allograft function and morphology were assessed. Patients were divided into three groups according to their glucose metabolism. Risk factors for diabetes were first assessed, and then changes in renal function were checked. Morphological changes in the allografts were examined by protocol biopsies. The overall incidence of diabetes was 16%. The development of diabetes was influenced significantly by the body mass index, the body weight and the age of the recipient. The incidence of diabetes was 8.6% in patients on cyclosporine A therapy and 28.8% in those on tacrolimus (p < 0.05). As to the morphology of the kidney, a significantly higher proportion of the biopsies showed severe interstitial fibrosis/tubular atrophy (p = 0.0004) and subclinical acute rejection ( p = 0.001) in the diabetic group compared to the normal one. This clinical study has revealed that the adverse effect of diabetes on the allograft can be detected with protocol biopsy before the manifestation of a functional deterioration.
Asunto(s)
Diabetes Mellitus/etiología , Rechazo de Injerto/etiología , Trasplante de Riñón/efectos adversos , Riñón/cirugía , Adulto , Biopsia , Glucemia/metabolismo , Distribución de Chi-Cuadrado , Diabetes Mellitus/sangre , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/tratamiento farmacológico , Femenino , Tasa de Filtración Glomerular , Prueba de Tolerancia a la Glucosa , Rechazo de Injerto/sangre , Rechazo de Injerto/diagnóstico , Rechazo de Injerto/fisiopatología , Humanos , Hungría/epidemiología , Hipoglucemiantes/uso terapéutico , Inmunosupresores/efectos adversos , Incidencia , Riñón/patología , Riñón/fisiopatología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
AIMS: Functional roles of calcium-activated potassium channels on the mechanical activity of epicardial coronary arteries obtained from a canine model of diabetes were investigated. METHODS: Coronary arteries were isolated from healthy, alloxan-diabetic and insulin-treated diabetic dogs. Basal tensions, contractions induced by the prostaglandin (PG) analogue, U46619, and endothelium-dependent relaxations to acetylcholine (ACh) were modified with charybdotoxin (CHTX) + apamin (APA), inhibitors of calcium-activated potassium channels, as well as with N(omega)-nitro-l-arginine (LNA) + indomethacin (INDO) to suppress the synthesis of nitric oxide (NO) and PGs. The relaxing effect of nitroprusside-sodium (SNP), an NO donor, was also determined. RESULTS: In diabetic coronary arteries, CHTX + APA did not change while LNA + INDO elevated the basal tension. PG-induced contractions were enhanced by CHTX + APA and by LNA + INDO in all the three groups of animals. CHTX + APA decreased the maximal relaxations to ACh in a partly insulin-dependent manner. LNA + INDO abolished the endothelium-dependent relaxations to ACh. In diabetic coronary arteries, the sensitivity to SNP-induced relaxation was enhanced, insulin independently, suggesting that NO could be partly responsible for maintaining intact ACh-induced vasorelaxation. CONCLUSION: In diabetic canine coronary artery, the vasomotor responses reflect up-regulation of calcium-activated potassium channels. This endothelial mechanism of the canine epicardial coronary artery may oppose vasoconstrictions in diabetic vascular tissue.
Asunto(s)
Apamina/farmacología , Caribdotoxina/farmacología , Vasos Coronarios/efectos de los fármacos , Diabetes Mellitus Experimental/fisiopatología , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio/fisiología , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacología , Acetilcolina/farmacología , Animales , Perros , Endotelio Vascular/efectos de los fármacos , Femenino , Técnicas In Vitro , Insulina/farmacología , Contracción Isométrica/efectos de los fármacos , Masculino , S-Nitroso-N-Acetilpenicilamina/farmacología , Vasoconstricción/efectos de los fármacos , Vasoconstrictores/farmacologíaRESUMEN
AIM: In diabetes mellitus, several cardiac electrophysiological parameters are known to be affected. In rodent experimental diabetes models, changes in these parameters were reported, but only limited relevant information is available in other species, having cardiac electrophysiological properties more resembling the human, including the rabbit. The present study was designed to analyse the effects of experimental type 1 diabetes on ventricular repolarization and the underlying transmembrane potassium currents in rabbit hearts. METHODS: Diabetes was induced by a single injection of alloxan (145 mg kg(-1) i.v.). After the development of diabetes (3 weeks), electrophysiological studies were performed using whole cell voltage clamp and ECG measurements. RESULTS: The QT(c) interval in diabetic rabbits was moderately but statistically significantly longer than measured in the control animals (155 +/- 1.8 ms vs. 145 +/- 2.8 ms, respectively, n = 9-10, P < 0.05). This QT(c)-lengthening effect of diabetes was accompanied by a significant reduction in the density of the slow delayed rectifier K(+) current, I(Ks) (from 1.48 +/- 0.35 to 0.86 +/- 0.17 pA pF(-1) at +50 mV, n = 19-21, P < 0.05) without changes in current kinetics. No differences were observed either in the density or in the kinetics of the inward rectifier K(+) current (I(K1)), the rapid delayed rectifier K(+) current (I(Kr)), the transient outward current (I(to)) and the L-type calcium current (I(CaL)) between the control and alloxan-treated rabbits. CONCLUSION: It is concluded that type 1 diabetes mellitus, although only moderately, lengthens ventricular repolarization. Diabetes attenuates the repolarization reserve by decreasing the density of I(Ks) current, and thereby may enhance the risk of sudden cardiac death.