Search Results
Results 251 - 300 of 952
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Okada N - - 1999
A method for the clinical assessment of glomerular hemodynamics has been published previously. We here examined whether, when using this method, renal creatinine clearance (Ccr) can be substituted for the glomerular filtration rate (GFR). The study subjects comprised 57 inpatients from Osaka City General Hospital: 30 with type 2 diabetes ...
Christensen P K - - 1999
BACKGROUND: The ability of the kidney to maintain constancy of the glomerular filtration rate (GFR) over a wide range of renal perfusion pressures is termed autoregulation. Defective autoregulation of GFR has been demonstrated in diabetic nephropathy. Whether this is also the case in patients with nondiabetic nephropathies is not known. ...
Kawabata M - - 1999
1. To obtain some insight into the renoprotective mechanism of the new calcium antagonist efonidipine hydrochloride, we evaluated the acute effects of efonidipine on proteinuria, glomerular haemodynamics and the tubuloglomerular feedback (TGF) mechanism in anaesthetized 24-25-week-old spontaneously hypertensive rats (SHR) with glomerular injury. 2. Efonidipine infusion at 10 micrograms/kg per ...
Willinger M - - 1999
Because of the closed plasma (secondary) circuit in the Microspheres based Detoxification System (MDS), a convective blood purification system, the same amount of filtrated plasma is backfiltrated into the blood circuit. Therefore, there is no direct way to determine the ultrafiltrate production rate, which is an important factor of efficiency. ...
Imanishi M - - 1999
AIMS/HYPOTHESIS: Results from animal models of glomerular hypertension have suggested that this disorder is one cause of albuminuria in diabetic nephropathy. We evaluated this hypothesis clinically. METHODS: The subjects were 20 patients with Type II (non-insulin-dependent) diabetes mellitus but without uraemia or hypertension: 8 had normoalbuminuria and 12 had albuminuria ...
Kato H - - 1999
In glomerular hypertension, mesangial cells (MC) are subjected to at least two physical forces: mechanical stretch and high transmural pressure. Increased transmural pressure, as well as mechanical stretch, promotes MC proliferation, which may enhance glomerulosclerosis. The exact mechanism of this effect is not fully understood. We examined the effects of ...
Fauvel J P - - 1999
Rilmenidine is an imidazoline I1-receptor agonist that centrally acts by reducing the sympathetic tone. There is strong experimental evidence that natriuresis could be evoked by proximal tubular I1-receptors that have also been isolated in human kidneys. However, in humans, the natriuretic effects of proximal tubular I1-receptors have never been demonstrated. ...
Smit J J - - 1999
BACKGROUND: Leukocyte filtration of systemic blood during cardiopulmonary bypass surgery to reduce post-operative morbidity has not yet been established because of the enormous leukocyte release from the third space. This study was designed to examine the efficiency and safety of leukocyte filtration by a new prototype large capacity leukocyte filter. ...
Cortes P - - 1999
Due to their elasticity, glomeruli will undergo excessive expansion and repetitive cycles of distension contraction under conditions of impaired glomerular pressure autoregulation and systemic arterial hypertension. These alterations in glomerular volume are associated with mesangial cell stretch which in turn stimulates the synthesis and deposition of ECM with eventual mesangial ...
Kobayashi M - - 1999
To characterize the configuration of "tunnel capillaries" in myocytes, an ultrastructural three-dimensional (3-D) study was performed on pressure-overloaded rat hearts induced by 16-week constriction of the ascending aorta. The hearts showed high incidence (6.1 +/- 3.6%) of tunnel capillary formation. Eighty-two myocytes (26.4%) had tunnel capillaries in a cubic block ...
Bangstad H J - - 1999
OBJECTIVE: To investigate whether the degree of glomerular structural lesions in young patients with type 1 diabetes and microalbuminuria was associated with urinary albumin excretion rate (AER) 6 years later and whether the AER level was influenced by blood glucose control, blood pressure, or glomerular filtration rate (GFR). RESEARCH DESIGN ...
Burlet A - - 1999
We performed renal function tests in 18 young patients, 1.8-14.6 years of age, with cyanotic congenital heart disease (CCHD). Glomerular filtration rate was normal (116 +/- 4.5 ml/min/1.73 m2), and renal plasma flow was decreased (410 +/- 25 ml/min/1.73 m2) with a rise in the filtration fraction (29 +/- 1.1%). ...
Fine L G - - 1999
British contributions to renal physiology trace back to the seminal contribution of William Bowman, who defined the structure of mammalian nephron and its blood supply and pointed out its likely mode of function. A series of contributions followed, which stemmed from a distinguished lineage of physiologists based at University College ...
Watenpaugh D E - - 1998
BACKGROUND: Net whole-body transcapillary fluid transport (TFT) between the circulation and the interstitial (extravascular) space may be calculated as: IV - deltaPV - UV - IL, where IV=infused or ingested volume (when applicable), deltaPV = change in plasma volume, UV=urine volume, and IL=insensible loss. RESULTS: Infusion of 30 mL/kg isotonic ...
Lafayette R A - - 1998
BACKGROUND: Pre-eclampsia is characterized by hypertension, proteinuria and edema. Simultaneous studies of kidney function and structure have not been reported. We wished to explore the degree and nature of glomerular dysfunction in pre-eclampsia. METHODS: Physiologic techniques were used to estimate glomerular filtration rate (GFR), renal plasma flow and afferent oncotic ...
Lewis D M - - 1998
BACKGROUND: Peripheral edema, in combination with severe proteinuria and low serum albumin levels, is pathognomonic of the nephrotic syndrome, yet the exact mechanism of its formation is unknown. Two of the most important of the factors in Starling's forces controlling fluid filtration across the capillary have hitherto not been studied ...
Cavarape A - - 1998
OBJECTIVE: To assess the site of action of endothelin-1 in vessels of different sizes in the kidney in vivo and investigate the function of endothelin A (ET(A)) receptors in mediating renal and systemic vasoconstriction. DESIGN: The luminal diameters of different vessels were measured and glomerular blood flow in cortical glomeruli ...
Carlsson P O - - 1998
The aim of the present study was to measure capillary blood pressure and interstitial pressure in transplanted pancreatic islets and to correlate these measurements to capillary and tubular pressures in the adjacent kidney. For this purpose, 250 syngeneic islets were implanted under the renal capsule of WF rats and studied ...
Kongstad L - - 1998
Measuring the capillary filtration coefficient (CFC) from the transvascular fluid filtration following a fixed increase in transcapillary hydrostatic pressure is a common method to estimate capillary hydraulic permeability (conductivity) in an organ. Constant flow pump perfusion with an artificial perfusate and a maximally dilated vascular bed are often used in ...
Ronco C - - 1998
BACKGROUND: Hemodialysis using high flux membranes today is a commonly used therapy. The primary advantage is the larger spectrum of molecules removed with these membranes, and the mechanism of removal is in part due to a phenomenon of filtration and backfiltration along the length of the hollow fibers. We hypothesized ...
Cao P - - 1998
Pressure assisting and pressure programming the inlet of the capillary electrophoresis instrument were used for the analysis of peptide mixtures and protein digests using capillary electrophoresis/electrospray ionization-mass spectrometry (CE/ESI-MS). CE/ESI-MS of peptide mixtures and tryptic digests of proteins was studied using three different types of capillary columns: (i) a freshly ...
Smith A C - - 1998
BACKGROUND: Calcium channel blockers (CCBs) are known to have differential effects on both changes in proteinuria as well as progression of diabetic nephropathy. No clinical study, however, has evaluated whether the differential antiproteinuric effects of CCBs may be explained by their effect on glomerular membrane permeability. We, therefore, tested the ...
Mahy I R - - 1998
Capillary filtration coefficient is a critical determinant of fluid flux across the microvascular wall. Changes in capillary filtration coefficient have been described in a number of disease processes. Measurement is typically made by venous occlusion plethysmography using either the upper or lower limb, but a variety of measurement protocols have ...
Ogborn M R - - 1998
We undertook a case-control study to evaluate the renal health of survivors of hemolytic-uremic syndrome (HUS) from the 1991 Arctic epidemic of Escherichia coli O157:H7 gastroenteritis 4 years after the epidemic. Eighteen children who developed HUS during the 1991 epidemic and 18 age- and sex-matched controls from the same community ...
Jia L - - 1998
The present investigation was performed to evaluate the effects of S-nitrosocaptopril, a novel vasodilator possessing the capacities of both an angiotensin converting enzyme inhibitor and an NO donor, on blood pressure and renal function in rats. S-nitrosocaptopril produced acute reductions in mean arterial pressure after both oral dosing (5, 10, ...
Holdstock N B - - 1998
The aim of this study was to determine glomerular filtration rate (GFR), effective renal plasma flow (RPF) and filtration fraction (FF) values in Pony foals during the first 10 days post partum in order to assess any age-related changes and the reliability of the single injection inulin/p-aminohippurate (PAH) method. Arterial ...
Romano G - - 1998
Nephron filtration rate (SNGFR), measured proximally by micropuncture using the technique of total collection of tubular fluid, may be spuriously high as the fall in intratubular pressure during collection may increase the net filtration pressure. Alternatively, the interrupted distal delivery of tubular fluid during proximal collection may up-regulate SNGFR by ...
Kurikawa Y - - 1998
OBJECTIVE: To study if, as predicted by calculations based on 3 Starling pressures, the fourth one, capillary pressure, may increase enough to contribute to joint swelling. METHODS: At magnifying arthroscopy, red cells mostly flow separated from each other in capillaries and precapillary vessels (arterioles). These are emptied of erythrocytes at ...
Ramsey C R - - 1998
Although studies of volume expansion (VE) in the Necturus suggest a major role for paracellular flux in reabsorption by the proximal tubule, results from morphologic or electrophysiologic studies of the effect of VE on the rat proximal tubule suggest only a minor role for paracellular transport. In the present study, ...
Kawabata M - - 1998
The effects of lemildipine, a new dihydropyridine calcium channel blocker, on renal hemodynamics and the tubuloglomerular feedback (TGF) mechanism were examined in anesthetized 9- to 10-wk-old spontaneously hypertensive rats (SHR). Lemildipine, 3 micrograms.kg-1 i.v., did not reduce mean blood pressure (MBP) but tended to increase GFR and increased urinary excretion ...
Ruggenenti P - - 1998
We investigated the predictors of the rate of glomerular filtration rate decline (delta GFR) and progression to end-stage renal failure (ESRF) in the 352 patients with proteinuric non-diabetic chronic nephropathies [urinary protein excretion rate (UProt) > or = 1 g/24 hr, creatinine clearance 20 to 70 ml/min/1.73 m2] enrolled in ...
Klaentschi K - - 1998
The glomerular basement membrane (GBM) is an important component of the filtration barrier that is the glomerular capillary wall. Previously GBM permeability has been investigated only under static pressures and often within a supraphysiological range. We used Matrigel as a model of GBM and formed membranes at the base of ...
Kai T - - 1998
Tsukuba hypertensive mice (THMs) are transgenic mice carrying human renin and angiotensinogen genes. The aim of this study was to evaluate the role of the renin-angiotensin system (RAS) in cardiac hypertrophy and renal disorders in THMs. After a 2-wk control period, 10-wk-old THMs were treated with lisinopril (ACEI group) or ...
Hoogenberg K - - 1998
OBJECTIVES: To assess the effects of low-dose dopamine on norepinephrine-induced renal and systemic vasoconstriction in normotensive healthy subjects. DESIGN: On separate days, either a low-dose dopamine (4 microg/kg/min) or a placebo (5% glucose) infusion was added in a single, blinded, randomized order to incremental norepinephrine infusions of 40, 80, and ...
Yu Y - - 1998
The ultrastructures of anionic sites in rat glomerular basement membranes (GBM) were studied at different perfusion pressures of 100, 150, 200 or 250 cm H2O by a quick-freezing and deep-etching (QF-DE) method, in addition to conventional fixation methods, using polyethyleneimine (PEI) as a cationic tracer. By the QF-DE method, three-dimensional ...
Brauer L P - - 1998
It was previously postulated on the basis of clinical data that the cardiovascular sequelae of extracorporeal whole-body hyperthermia (e-WBH), i.e., hypotension (which requires catecholamine support) results in unique nephrotoxicity in combination with select chemotherapeutic agents. In an attempt to explain this phenomenon, we mimicked e-WBH physiological conditions in a rat ...
Elger M - - 1998
In the present study we provide a detailed structural analysis of the vascular pole of superficial and midcortical glomeruli of the rat kidney. A description of the juxtaglomerular portions of the afferent and efferent arterioles, the extraglomerular mesangium and the glomerular stalk is included. The specific structural elaboration of the ...
Lin W - - 1998
The stop-flow approach was used to investigate where filtration occurs in the pulmonary vasculature after elevation of left atrial pressure and aspiration of HCl. Rat lungs were perfused for 11 min at zero left atrial pressures, and then flow was stopped for 10 min and left atrial pressures were increased ...
Tarif N - - 1997
The vast majority of animal data derived from models of either remnant kidney or diabetes demonstrate that dihydropyridine (nifedipine-like) calcium-channel blockers (DHPCCBs) effectively reduce arterial pressure but do not significantly affect proteinuria nor prevent development of glomerular scarring. Conversely, the non-DHPCCBs such as diltiazem and verapamil blunt both the rise ...
Christensen P K - - 1997
We investigated the effect of acute lowering of blood pressure (BP) upon glomerular filtration rate (GFR) in hypertensive non-insulin-dependent diabetes mellitus (NIDDM) patients, 14 with diabetic nephropathy and 12 with normoalbuminuria. The study was performed twice with the subjects receiving an intravenous injection of either clonidine (150 to 225 micrograms) ...
Aurell M - - 1997
BACKGROUND: Hypertension is a significant cause of end-stage renal failure and effective treatment of hypertensive will reduce the progression rate of chronic renal failure in various kidney disorders. Different classes of drugs may be more effective than others in this respect. In this study we compared the effects on the ...
Dhadwal A - - 1997
A theoretical model is developed to simulate the flow of blood through the capillary network in a single alveolar septum. The objective is to study the influence of random variability in capillary dimension and compliance on flow patterns and pressures within the network. The capillary bed is represented as an ...
Kawata T - - 1997
Effects of dihydropyridine (DHP) Ca2+ channel blocker (CaB) on glomerular hemodynamics are controversial. We examined the effects of two DHP derivatives, benidipine hydrochloride (BDP) and nifedipine (NDP), on glomerular hemodynamics by an in vivo micropuncture method by using spontaneously hypertensive rats (SHRs). Systemic bolus infusion of BDP (4 microg/kg) or ...
Heller J - - 1997
The influence of gradual decline in renal perfusion pressure (RPP) due either to renal artery clamping (C) or to haemorrhagic hypotension (HH) was studied using micropuncture techniques in anaesthetized dogs. The decrease in renal blood flow (RBF) was more profound and set in earlier during HH than during C, where ...
Villa E - - 1997
Rapid degradation of prostacyclin (PGI2) inherent to its molecular structure has long been a major limitation in assessing the natriuretic effect of this prostaglandin. The recent availability of the stable PGI2 analogue iloprost now allows for a comparative study with prostaglandin E2 (PGE2). In the present study conducted in six ...
Vargas F - - 1997
The renal-excretory responses to changes in renal perfusion pressure (RPP) were studied in anesthetized young (3 mo old), adult (12 mo old), and senescent (24 mo old) rats to evaluate whether the pressure diuresis and natriuresis mechanism is altered as a function of age. Experiments were performed in anesthetized animals ...
Boim M A - - 1997
The role of catecholamines in the distribution of intrarenal blood flow and in single-nephron glomerular filtration rate (SNGFR) was evaluated in anesthetized Wistar rats by the Hanssen technique. Epinephrine (EPI) and norepinephrine (NOR) were infused to produce elevations of 20-30 mmHg in mean arterial pressure. Superficial and juxtamedullary nephron perfusion ...
Berrut G - - 1997
Hypertension and non-insulin-dependent diabetes mellitus (NIDDM) are two major risk factors for end-stage renal failure. The value of microalbuminuria (urinary albumin excretion [UAE]: 30-300 mg/24 h) as an indicator of the glomerular filtration rate (GFR) is not known in these patients. METHODS: The relationships between microalbuminuria and GFR in subjects ...
Pecis M - - 1997
OBJECTIVE: To analyze the blood pressure patterns in normoalbuminuric IDDM patients with glomerular hyperfiltration. RESEARCH DESIGN AND METHODS: A controlled cross-sectional study of 38 normotensive normoalbuminuric (urinary albumin excretion rate < 20 micrograms/min) IDDM patients (18 hyperfiltering [glomerular filtration rate > 134 ml.min-1 1.73 m-2] and 20 normofiltering) and 20 ...
Ito S - - 1997
1. The balance of vascular tone of the afferent and efferent arteriole is a crucial determinant of glomerular haemodynamics. Despite their intimate anatomical relationship in the juxtaglomerular apparatus, the mechanisms that regulate afferent and efferent arteriolar tone are different. 2. In the afferent arteriole, two intrinsic mechanisms, the myogenic response ...
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