Search results for "Renal circulation"
showing 10 items of 16 documents
A new principle to normalize plasma concentrations allowing single-sample clearance determinations in both children and adults.
1992
A sufficiently accurate quantification of renal function requiring only one plasma sample without an additional gamma-camera study has, until now, only been possible in adults. A new principle will be presented here allowing the universal application of known algorithms, regardless of the clearance substance used, by normalizing the plasma concentrations with respect to the individual body dimensions of the patients - for infants as well as for adults. In this respect, algorithms are developed for clearance determinations using technetium-99m mercaptoacetyltriglycine (99mTc-MAG3), which are based on steady-state studies as the reference. They allow the calculation of quantitative clearance …
Renal plasma flow, filtration fraction and microalbuminuria in hypertensive patients: Effects of chronic smoking
2005
SUMMARY: Introduction: Albumin excretion rate is usually increased in people who smoke, but the physiological basis of this phenomenon is not fully understood. Methods: The effect of chronic smoking on renal haemodynamics was studied in a cohort of 66 men. Twenty-seven were smokers and 36 were hypertensive. In all subjects, the albumin excretion rate was evaluated; in hypertensive patients, a renoscintigraphic evaluation of renal plasma flow and glomerular filtration were carried out and the filtration fraction was calculated. Results: The hypertensive smoking population presented an increased urinary albumin excretion rate in comparison with hypertensive non-smoking patients. No signifi…
Association of renal resistive index with aortic pulse wave velocity in hypertensive patients
2014
Background: Recent data suggest that renal haemodynamic parameters obtained by duplex Doppler sonography, especially the intrarenal resistive index (RI), may be associated with systemic vascular changes. However, conflicting data exist about the independent relationship between aortic stiffness and RI. The aim of this study was to evaluate the relationship between RI and arterial stiffness, assessed by aortic pulse wave velocity (aPWV), in hypertensive patients. Design: Cross-sectional study. Methods: We enrolled 264 hypertensive subjects aged between 30 and 70 years. They were divided into two groups, either with normal renal function (n=140) or with chronic kidney disease (CKD) (n=124). E…
Effects of cilazapril on renal haemodynamics and function in hypertensive patients: a randomised controlled study versus hydrochlorothiazide.
1995
In this study the efficacy and safety of short-term cilazapril administration on renal haemodynamics were evaluated in mild to moderate hypertensive subjects. Our final goal was to evaluate whether the reduction in blood pressure achieved by treatment was associated with maintained renal function. After a run-in period with placebo, 40 hypertensive subjects without renal or cardiac diseases were randomly allocated to a double-blind 4 week controlled trial with cilazapril 5 mg once a day (20 patients) or hydrochlorothiazide 25 mg once a day (20 patients). Renal haemodynamics measurements included effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) by radionuclide study us…
Insulin resistance and glomerular hemodynamics in essential hypertension
2002
Insulin resistance and glomerular hemodynamics in essential hypertension. Background Arterial hypertension is an important cause of end-stage renal failure. Insulin has been shown to modify glomerular hemodynamics in hypertensive subjects. The aim of this work, therefore, was to observe the relationships between renal hemodynamics and insulin resistance in arterial hypertension. Methods Sixty-two non-diabetic hypertensive patients and 25 healthy normal subjects were studied. Renal plasma flow and the glomerular filtration fraction were determined by renoscintigraphy and the insulin sensitivity by an oral glucose test. Results Renal plasma flow in hypertensive subjects was lower than expecte…
Intra-renal hemodynamics and carotid intima-media thickness in the metabolic syndrome.
2009
Aims: Metabolic syndrome (MetS) is associated with increased cardiovascular risk. We hypothesize that early vascular changes are already present at the time of diagnosis of MetS. The relationship of different measures of early vascular impairment with body fat distribution and the natural progression of MetS was examined in newly diagnosed subjects non-pharmacologically treated. Methods: 246 consecutively enrolled subjects were categorized according to the presence of MetS and type 2 diabetes (T2D). Intra-renal Doppler flow was used to ascertain resistive (RI) and pulsatility (PI) indices as markers of vascular resistance. Carotid intima-media thick- ness (IMT), cutis-rectis (CR) and rectis…
Relationship Between Carotid Atherosclerosis and Pulse Pressure with Renal Hemodynamics in Hypertensive Patients.
2015
BACKGROUND Structural atherosclerotic damage, arterial stiffness, pulse pressure (PP), and renal hemodynamics may interact and influence each other. Renal resistance index (RRI) appears as a good indicator of systemic vascular changes. The aim of our study was to assess the independent relationships of carotid intima-media thickness (cIMT), aortic pulse wave velocity (aPWV), and peripheral PP with RRI in hypertensives with various degrees of renal function. METHODS We enrolled 463 hypertensive patients (30-70 years) with normal renal function (group 0; n = 280) and with chronic kidney disease (groups I-V; n = 183). All subjects underwent ultrasonographic examination of intrarenal and caroti…
Early Vascular Aging in Normotensive Patients With Systemic Lupus Erythematosus
2015
Connective tissue diseases, like systemic lupus erythematosus (SLE), are associated with early and accelerated atherosclerosis. Recently, the concept of “early vascular aging” (EVA) has been more widely accepted. Aortic stiffness is one of the important markers of EVA. We evaluated EVA and subclinical atherosclerosis, by measuring aortic pulse wave velocity (aPWV) and carotid intima–media thickness (cIMT), in 50 normotensive patients with SLE (mean age: 39 ± 12 years). We compared these participants with 50 age- and sex-matched patients with essential hypertension (EH) and 20 healthy controls. Each participant underwent 24-hour ambulatory blood pressure monitoring (ABPM), aPWV, and cIMT me…
ASSOCIATION OF RENAL RESISTIVE INDEX WITH MARKERS OF EXTRARENAL VASCULAR CHANGES IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS
2016
Introduction: Recent data suggest that renal hemodynamic parameters obtained by duplex Doppler sonography, especially the intrarenal resistive index (RRI), may be associated with systemic vascular changes. However, limited and conflicting data exist about the relationship between aortic stiffness and RI in autoimmune diseases, like systemic lupus erythematosus (SLE). Aim: To evaluate the relationship between RRI and arterial stiffness, assessed by aortic pulse wave velocity (aPWV), and between RRI and carotid atherosclerosis, evaluated by intima-media thickness (IMT) measurement in patients with SLE. Methods: In this cross-sectional study, we enrolled 39 SLE subjects (mean age 39 years) tha…
Autoradiographic technique to assess distribution of blood flow within organs
1969
A method is described for assessing the distribution of blood flow within organs. Microspheres, 5–50 μ in diameter, labelled with a beta-emitting isotope were injected into the left ventricle of experimental animals. The distribution of the indicator within the tissues, which is assumed to represent the regional distribution of flow, was visualized and measured quantitatively by autoradiography. Local flow rates in areas of about 1,2 mm in diameter could be determined. Application of the technique for the study of regional myocardial and renal circulation is demonstrated.