Search Results
Results 351 - 400 of 952
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Hedderwick S A - - 1995
We describe a 29-year-old woman with persistent arterial hypertension which resolved following complete excision of a capillary haemangioblastoma from within the spinal cord at the cervico-medullary junction. Immunohistochemical staining was positive for neuropeptide Y in capillary walls and nerves in the tumour. This raises the possibility of an association between ...
Hansen H P - - 1995
Initiation of antihypertensive treatment (AHT) in hypertensive insulin-dependent diabetic (IDDM) patients with diabetic nephropathy (DN) induces a faster initial (0 to 6 months) and a slower subsequent (6 months to end of observation) decline in GFR [delta GFR (ml/min/month) approximately 1.5 vs. 0.35]. Whether this initial phenomenon is reversible (hemodynamic) ...
Klahr S - - 1995
In the Modification of Diet in Renal Disease Study, a follow-up (mean, 2.2 yr) of 200 study participants with autosomal dominant polycystic kidney disease (ADPKD) was conducted to determine the effect of lowering protein intake and blood pressure on the rate of decline in GFR. The rate of decline was ...
Maki D D - - 1995
BACKGROUND: Although many studies have examined the effects of antihypertensive agents on proteinuria and glomerular filtration rate in patients with kidney disease, many questions remain unresolved. These questions include whether the effects of agents differ, whether their effects are similar in diabetic and nondiabetic patients with renal disease, and whether ...
Lee J - - 1995
The objective of this study was to investigate the structure of capillaries in rat skeletal muscle and their mechanical properties over a wide range of transmural pressures. Capillaries were fixed at controlled pressures and studied with intravital and electron microscopy. Capillary lumen dimensions depend on the local transmural pressure, with ...
Motwani J G - - 1995
We studied six healthy male subjects in a randomized, placebo-controlled, single-blind fashion to determine the comparative effects on renal hemodynamics and natriuresis of the angiotensin-converting enzyme inhibitor enalapril (5 mg on each of 5 days preceding the study), the neutral endopeptidase inhibitor candoxatrilat (200 mg IV), and the combination of ...
Jahr J - - 1995
OBJECTIVE: To analyze the local circulatory effects of prostacyclin in skeletal muscle. DESIGN: A prospective experimental study. SETTING: A university laboratory. SUBJECTS: Twelve adult cats. INTERVENTIONS: The study was performed on autoperfused, sympathectomized gastrocnemius muscle. MEASUREMENTS AND MAIN RESULTS: Arterial blood flow, total and segmental vascular resistances (arterial vessels of ...
Fransen R - - 1995
1. Little direct information is available on the actions of angiotensin II beyond the proximal tubule. We therefore studied the effect of a mildly vasoconstrictive dose of angiotensin II on tubular handling of water, sodium (Na+) and lithium (Li+) in rats by means of free-flow micropuncture at the late proximal ...
Alejandro V - - 1995
Postischemic filtration failure in experimental animals results primarily from depression of the transcapillary hydraulic pressure difference (delta P), a quantity that cannot be determined in humans. To circumvent this limitation we determined the GFR and each of its remaining determinants in transplanted kidneys. Findings in 12 allografts that exhibited subsequent ...
Thorup C - - 1995
Renal effects of acute renal denervation (DNX) were studied in anaesthetized rats. In a first series, whole kidney clearance measurements were made 120 and 240 min after unilateral DNX. At 240 min, urine production was 3.59 +/- 0.87 microL min-1 in control kidneys and 7.74 +/- 1.97 microL min-1 in ...
Hansson L - - 1995
Antihypertensive treatment has been shown to slow down the decline in glomerular filtration rate (GFR) with time. This has been most extensively studied in patients with diabetic nephropathy and, to some extent, with other forms of renal disease. Angiotensin-converting enzyme (ACE) inhibition has been shown to be more effective in ...
Saad W A - - 1995
We investigated the participation of the beta-adrenoceptors of the septa area (SA) in sodium and potassium excretion and urine flow. The alterations in arterial pressure and some renal functions were also investigated. The injection of 2.10(-9) to 16.10(-9) M of isoproterenol, through a cannula permanently implanted into the SA produced ...
Tucker B J - - 1995
Head-down tilt (HDT) is utilized to simulate microgravity and produces a cephalad fluid shift, which results in alterations in fluid and electrolyte balance. These changes in volume homeostasis are due, in part, to alterations in multiple volume control mechanisms in which renal function is a major participant. We have previously ...
Badeer H S - - 1995
It is accepted that glomerular vascular resistance to blood flow is represented by a pressure drop of only a few mm Hg, but the hemodynamic basis for this concept is generally not well known. Our purpose is to review the evidence supporting the low resistance concept and to provide an ...
Anderson W P - - 1995
The relationship between arterial pressure and the rate of Na+ excretion is regulated by a number of mechanisms- some well known, some newly discovered, and probably some yet to be discovered. These mechanisms affect either the amount of Na+ filtered at the glomerulus or its rate of reabsorption from the ...
Numabe A - - 1994
Cardiac failure is multifactorial in causation, and the underlying physiologic mechanisms are variable, yet their renal effects have been considered more homogeneous. To investigate and compare the intrarenal hemodynamic characteristics in two experimental types (low- and high-output) of cardiac failure, renal micropuncture studies were performed in rats after myocardial infarction ...
Hodges U M - - 1994
Modified ultrafiltration after cardiopulmonary bypass in children has been shown to be associated with an increase in arterial blood pressure. As part of a series of studies to investigate the possible causes of this blood pressure elevation, the hypothesis that if filtration was removing a significant amount of fentanyl, then ...
Lockhart J C - - 1994
This study investigated the role of volume status and perfusion pressure on the hemodynamic response of cortical and medullary renal capillaries to systemic inhibition of nitric oxide. NG-Monomethyl-L-arginine (L-NMMA) was infused intravenously (15-mg/kg bolus and 500-micrograms.min-1.kg-1 infusion), and blood flow in cortical capillaries (QCC) and in descending (QDVR) and ascending ...
Thompson A - - 1994
The short-term systemic and renal hemodynamic effects of two stroma-free hemoglobin (SFH) solutions, one unmodified and the other modified by cross-linking, were examined in anesthetized rats after hemorrhagic hypotension. Both forms of SFH increased mean arterial pressure (MAP) and glomerular filtration rate (GFR) to baseline (prehemorrhage) values. The increase in ...
Ornstein E - - 1994
To study the effect of AVM occlusion on cerebrovascular haemodynamics, a simplified model was simulated consisting of a feeding artery supplying a capillary bed in parallel with a fistula-like malformation, both emptying into a draining vein. An electrical circuit analogue of the physiologic system was developed using lumped proximal and ...
Thorup C - - 1994
This study was designed to compare the effects of systemic and intratubular infusions of the nitric oxide (NO) synthase inhibitor N omega-nitro-L-arginine (L-NNA) on the tubuloglomerular feedback (TGF) mechanism in anesthetized rats. We recently showed that intravenous infusion of L-NNA led to increases in mean arterial blood pressure (Pa), proximal ...
Shore A C - - 1994
The hemodynamic hypothesis suggests that raised capillary pressure may play a role in the pathogenesis of diabetic microangiopathy. Although patients with non-insulin-dependent diabetes mellitus (NIDDM) and insulin-dependent diabetes NIDDM) develop a similar range of microvascular complications, differences in their expression and prevalence suggest that different pathogenic mechanisms may be operational. ...
Gibson K J - - 1994
To determine the cause of the transient natriuresis in lambs within 1-2 h of birth, renal function and blood volume (BV) were measured in nine chronically catheterized fetal sheep aged 139-145 d before and after delivery by cesarean section. After delivery, sodium excretion increased 8-fold. This was due to a ...
Gabbai F B - - 1994
The cell-free isolated perfused kidney (IPK) is characterized by normal glomerular filtration rate (GFR) and very low filtration fraction (FF). Addition of erythrocytes to the perfusate (IEPK) increases FF while maintaining "normal" GFR levels. Micropuncture studies were performed in IPK and IEPK to establish the determinants of the glomerular ultrafiltration ...
Yagil Y - - 1994
CS-905 is a dihydropyridine calcium channel antagonist which stands out for its prolonged hypotensive effect, and which is currently under investigation for the treatment of hypertension. The aim of the current series of studies was to investigate the effects of CS-905 on renal function in relation to its effects on ...
Hahn M - - 1994
1. The effect of a rapid local reduction in finger temperature on finger nailfold capillary blood pressure and blood cell velocity was investigated in healthy subjects. 2. Cooling was achieved by placing the finger into an adjustable copper cylindrical finger holder, which incorporated a Peltier element within its base; thus ...
Blantz R C - - 1994
The glomerular barriers to water and macromolecular movement were examined 2 and 24 h after the administration of a monoclonal antibody (mAb) specific to an antigen located on the epithelial slit diaphragm and the external aspect of the glomerular basement membrane. By micropuncture techniques 2 h after mAb administration, single-nephron ...
Heller J - - 1994
It has been suggested that angiotensin-converting enzyme (ACE) inhibition is accompanied by enhanced bradykinin and prostaglandin activities, which may contribute to the renal haemodynamic actions of ACE inhibitors. Therefore we investigated renal function by clearance and micropuncture techniques in dogs maintained either on normal or low-salt diet before and after ...
Ferrario R - - 1994
To assess the functional relevance of the enhanced glomerular nitric oxide (NO) synthesis during acute nephrotoxic serum (NTS) nephritis, a NO synthesis inhibitor (NOI) NG-monomethyl-L-arginine was administered to normal (N + NOI) and acutely nephritic (NTS + NOI) Munich-Wistar rats, and systemic and glomerular hemodynamic responses were contrasted with those ...
Inman S R - - 1994
BACKGROUND: In the kidney, the afferent and efferent arterioles normally constrict or dilate in response to changes in systemic blood pressure to maintain glomerular filtration while protecting the glomerulus from excessive pressure. In diabetes mellitus and hypertension, the two most common causes of kidney failure, sustained hypertension within the glomerulus ...
Kontessis P S - - 1994
We measured Na+/Li+ CT in 16 IgA nephropathy patients. Records were reviewed (mean observation period 5.5 years) for serial measurements of blood pressure (BP), urinary protein excretion, GFR (51Cr-EDTA) and plasma creatinine. Na+/Li+ CT correlated with the slope of the plot of GFR versus time (rs = -0.66, p = ...
Bugge J F - - 1994
The relationship between angiotensin II and renal prostaglandins, and their interactions in controlling renal blood flow (RBF) and glomerular filtration rate (GFR) were investigated in 18 anaesthetized dogs with acutely denervated kidneys. Intrarenal angiotensin II infusion increased renal PGE2 release (veno-arterial concentration difference times renal plasma flow) from 1.7 +/- ...
Weinmann W - - 1994
Two capillary electrophoretic (CE) separation techniques with either simultaneous solvent flow induced by hydrostatic pressure or CE followed by low pressurization with helium were developed for the analysis of extremely hydrophobic proteins, such as the lung surfactant protein SP-C. For both related procedures, buffer solutions containing up to 70% of ...
Klahr S - - 1994
BACKGROUND: Restricting protein intake and controlling hypertension delay the progression of renal disease in animals. We tested these interventions in 840 patients with various chronic renal diseases. METHODS: In study 1, 585 patients with glomerular filtration rates of 25 to 55 ml per minute per 1.73 m2 of body-surface area ...
Oizumi K - - 1994
An animal model having both hypertension and reduced renal function was produced by intraperitoneal injection of puromycin aminonucleoside (PAN) in spontaneously hypertensive rat (SHR). Using this model, two different dihydropyridine Ca blockers, CS-905 and nicardipine, were compared with regard to the relationship between hypotensive effects and changes in renal function ...
Sampson M J - - 1994
To examine the relationships between the normal dietary intakes of protein and phosphate, blood pressure, and the progression of diabetic nephropathy, we prospectively studied 20 Type 1 diabetic subjects of mean age 43 +/- 10 years (SD) with early nephropathy (mean serum creatinine 115 +/- 43 mumol l-1) over 1 ...
Caidahl K - - 1994
OBJECTIVE: With the advent of recombinant human GH (rhGH), it has become possible in controlled clinical studies to explore the effects of GH replacement in adults with GH deficiency. The objective of this study was to determine cardiovascular and renal effects of GH replacement in adults with GH deficiency. PATIENTS: ...
Denton K M - - 1994
1. The renal effects of inhibiting nitric oxide (NO) formation using N-nitro-L-arginine (NOLA, 20 mg kg-1) were examined using micropuncture techniques in pentobarbitone-anaesthetized rabbits. 2. Renal vascular resistance doubled from 2.7 +/- 0.5 to 5.0 +/- 1.1 mmHg ml-1 min-1 after NOLA (P < 0.01), with similar percentage increases in ...
Aukland K - - 1994
Every minute, the cortical peritubular capillaries in a 1-g rat kidney take up more than 0.5 ml tubular reabsorbate. Studies of renal lymph and measurements of pressure in capillaries (Pc) and interstitium (Pi) indicate that normally the protein colloid osmotic pressure of peritubular capillary plasma (COPp) provides the necessary absorptive ...
Johnsson E - - 1994
A modified rat kidney preparation was used to explore how changes in hydrostatic pressure affect the permselective properties of the glomerular capillary bed. The maximally vasodilated kidneys of 18 rats were perfused with albumin solutions (16.7 g l-1) at different flow rates and hence arterial pressures (PA). One kidney in ...
Johnsson E - - 1994
The renal hemodynamics were studied in an isolated perfused rat kidney model modified for investigations of the glomerular permeability characteristics. The tubular reabsorptive activity was inhibited by perfusion at low temperature (8 degrees C) in the presence of furosemide and nitroprusside resulting in a dramatic increase in the filtered load ...
Kriz W - - 1994
In a previous study of the changes in glomerular structure in the isolated perfused kidney (IPK), perfusion at high pressures lead to an enlargement of the glomerular tuft and to the formation of giant capillaries. The present paper analyzes the morphological and dimensional changes of the peripheral glomerular capillary wall ...
Guasch A - - 1994
Physiologic and morphologic techniques were used to elucidate the determinants of the GFR in 25 nephrotic patients with minimal change nephropathy. They were divided into two groups according to the finding of either a normal (Group 1, N = 13) or a depressed (Group 2, N = 12) inulin clearance. ...
Ronco C - - 1994
A new blood module for continuous renal replacement therapies has been utilized to perform CVVH in critically ill patients. The features of the new module named (HP300 and manufactured by Medica srl (Medolla, Modena) are the easy installation and transportability to the bedside, the simple and safe management and the ...
Wenzel U O - - 1994
We have recently shown that treatment with the calcium channel blocker nitrendipine may aggravate albuminuria and glomerular injury in rats with two-kidney, one clip renovascular hypertension if arterial blood pressure is not reduced. To test whether nitrendipine also exerts its adverse renal effects when normotension is achieved, we examined the ...
Day R O - - 1993
Nailfold capillaries in 28 patients with OA affecting the distal interphalangeal joints were compared to 23 age- and sex-matched controls without OA. Patients with OA showed a significantly lower density of capillaries in their nailfolds and significantly more capillary morphological abnormalities including haemorrhage, 'drop out', dilatation and irregularity. There was ...
Dillon J J - - 1993
Antihypertensive therapy reduces the rate at which glomerular filtration rate (GFR) declines (delta GFR) in diabetic nephropathy; however, the optimal blood pressure is unknown. The quantitative relationship between treated blood pressure and delta GFR was analyzed retrospectively in 59 patients with established diabetic nephropathy and treated hypertension using weighted univariate ...
Braam B - - 1993
The balance between a high filtration rate and high reabsorption rate in the kidney is critical in the maintenance of extracellular fluid volume. One of the mechanisms that maintain this balance is the tubuloglomerular feedback (TGF) mechanism, which operates at the level of the macula densa assessing the load and/or ...
Holstein-Rathlou N H - - 1993
In normotensive, halothane-anesthetized rats, oscillations can be found both in the single-nephron blood flow and in the tubular pressure. Experimental data and computer simulations support the hypothesis that the oscillations are caused by the tubuloglomerular feedback (TGF) mechanism. Model studies show that the key parameters determining the stability of the ...
Nowicki P T - - 1993
To determine whether intrinsic regulation of capillary exchange capacity is age-dependent during early postnatal life, we measured the capillary filtration coefficient (Kf,c), an index of capillary exchange capacity, within isolated perfused intestine from 3- and 35-day-old swine at different arterial pressures. Kf,c was determined gravimetrically, by means of the flow-equilibration ...
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