RESUMEN
The pseudointimal formation in an expanded polytetrafluoroethylene graft implanted in the canine inferior vena cava was studied by light and transmission electron microscopy. Five of 6 grafts in the control group and all of the 10 grafts in the batroxobin-defibrinogenated group were patent, and provided for the investigation. The thickness of the mural thrombus formed within 3 days was significantly decreased in the severely defibrinogenated dogs, in which the fibrinogen concentration was below 0.40 gm/L, as compared to the controls and the moderately defibrinogenated dogs, in which the fibrinogen concentration was at highest 0.72-0.87 gm/L. In spite of reducing the fibrinogen concentration to unmeasurable levels after 3 days, there was no obvious difference in the process of pseudointimal formation between the moderately defibrinogenated dogs and the controls. In the severely defibrinogenated dogs, loose and spongoid mural thrombus required a longer time to be reorganized.
Asunto(s)
Órganos Artificiales , Politetrafluoroetileno , Vena Cava Inferior/ultraestructura , Animales , Batroxobina/farmacología , Perros , Relación Dosis-Respuesta a Droga , Fibrinógeno/metabolismo , Microscopía Electrónica , Trombosis/patología , Factores de TiempoRESUMEN
The study investigated the effects of intravenous infusion of atrial natriuretic peptide (human ANP 99-126) on renal function and central hemodynamics after coronary artery bypass grafting (CABG), and the ability of ANP to reverse the acute nephrotoxic effects of cyclosporine after heart transplantation. Ten patients with an EF > 0.5 and normal renal function were studied 2 to 4 hours after CABG surgery. Furthermore, six heart transplant recipients receiving cyclosporine for immunosuppression who developed renal dysfunction 2 to 4 days after transplantation were studied. Standard urinary clearance of 51Cr-EDTA and PAH was used to study the effects of ANP on glomerular filtration rate (GFR) and renal blood flow (RBF). Baseline measurements were first performed during two 30-minute periods. Incremental infusion rates of ANP were then administered for three consecutive 30-minute periods (25, 50, and 100 ng/kg/min), followed by two 30-minute post-ANP control periods. Marked increases in urinary flow (UF), GFR, filtration fraction (FF), and fractional urinary excretion of Na+ were observed in the CABG patients with increasing doses of ANP, while RBF was unchanged. Mean arterial pressure decreased by around 15% at the highest ANP dose. In the heart transplant recipients, baseline GFR was markedly reduced compared to pretransplantation values (-65%). UF, GFR, and RBF increased 240%, 69%, and 53%, respectively, while renal vascular resistance decreased 45% during the highest dose of ANP infused. At this ANP dose level, circulating ANP concentrations were sixfold to eightfold higher than the preinfusion control level.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Factor Natriurético Atrial/farmacología , Puente de Arteria Coronaria , Ciclosporina/uso terapéutico , Trasplante de Corazón , Riñón/efectos de los fármacos , Adolescente , Adulto , Anciano , Factor Natriurético Atrial/sangre , Presión Sanguínea/efectos de los fármacos , Ácido Edético , Femenino , Tasa de Filtración Glomerular/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Trasplante de Corazón/fisiología , Humanos , Masculino , Persona de Mediana Edad , Circulación Renal/efectos de los fármacos , Sodio/orina , Resistencia Vascular/efectos de los fármacos , Ácido p-Aminohipúrico/orinaRESUMEN
A model for quality assessment of heart transplantation that combines a scientific method for studying the recipients' quality of life and a basis for a method of clinical work by nurses and other health care professionals is discussed. Besides its use as a research method, this model also may serve as an instrument for documenting patients' biopsychosocial status, including coping capacity, and for evaluating nursing interventions.