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Fukuda Michio - - 2004
BACKGROUND: We reported that patients with sodium sensitive type of hypertension exhibited the lack of nocturnal fall in blood pressure with enhanced natriuresis during night. Sodium sensitivity is caused by diminished glomerular filtration capability and/or augmented tubular reabsorption of sodium, and seems tightly linked with glomerular capillary hypertension. In the ...
Fesler Pierre - - 2004
Blood pressure is a marker of elevated risk for cardiovascular disease, even within the normotensive range. The present study evaluates cardiorenal modifications observed in normotensive (<140/90 mm Hg) subjects. Using World Health Organization-International Society of Hypertension definitions, 265 normotensive subjects were categorized as having optimal (n=73), normal (n=84), and high-normal ...
Shin Sehyun - - 2004
A newly designed pressure-scanning capillary viscometer is extended to measure the viscosity of whole blood over a range of shear rates without the use of anticoagulants in a clinical setting. In the present study, a single measurement of pressure variation with time replaces the flow rate and pressure drop measurements ...
Amoussou-Guenou K M - - 2004
The Microfiltrometer consists of a filtration system for diluted erythrocyte suspensions, through a filter containing 30 cylindrical micropores, 5 microm in diameter, under the influence of a driving pressure. A feeding sinusoidal alternating current of 40 kHz, 300 microA is delivered to the filter. The change in impedance is collected ...
Hahn Martin - - 2004
PGE(1) or PGI(2) acutely increase total skin perfusion in healthy volunteers. This study investigated whether skin nutritive perfusion and capillary pressure were increased by acute infusion of PGE(1). In a double blind randomised placebo controlled study the effect of Alprostadil (PGE(1), Prostavasin, intra-venous, infusion rate: 0.38 microg/h/kg,) on skin nailfold ...
Delles Christian - - 2003
BACKGROUND: To elucidate the renoprotective mechanism of AT(1)-receptor blockers, we compared the effects of the AT(1)-receptor blocker valsartan with those of the calcium channel blocker amlodipine on renal hemodynamics and microcirculation. METHODS: A total of 58 patients (50.2 +/- 9.0 years) with mild to moderate essential hypertension were included in ...
Koyama Tetsuzi - - 2003
We have developed a quantitative filtration apparatus to evaluate erythrocyte deformability, using a precision metal filter which we developed. The test material is sucked into the filter through the action of decreasing negative pressure. The device automatically gives a liquid level (height)-time relation and a pressure-flow rate relation, similar to ...
Hladunewich M A - - 2004
We evaluated the glomerular filtration rate (GFR) during the second postpartum week in 22 healthy women who had completed an uncomplicated pregnancy. We used physiological techniques to measure GFR, renal plasma flow, and oncotic pressure and computed a value for the two-kidney ultrafiltration coefficient (K(f)). We compared these findings with ...
Vupputuri Suma - - 2003
Few cohort studies have examined the longitudinal association between change in blood pressure and decline in kidney function among treated hypertensive patients without chronic kidney disease. We conducted a nonconcurrent cohort study to examine the effects of blood pressure on estimated glomerular filtration rate and early kidney function decline (rise ...
Schell-Feith Eveline A - - 2003
The aim of the study was to evaluate the natural course of nephrocalcinosis (NC) in preterm neonates and the effect of NC on blood pressure and renal glomerular and tubular function. In a prospective observational study of 201 preterm neonates (gestational age <32 weeks) NC was present at term in ...
Pedrini Luciano A - - 2003
BACKGROUND: Increased middle-molecular uremic toxin removal seems to favorably influence survival in dialysis patients. The aim of this study was to verify if, in on-line mixed hemodiafiltration, solute removal by convection may be enhanced by forcing the ultrafiltration rate (QUF) and optimizing the infusion technique in order to achieve the ...
Williams Donna A - - 2003
Magnitude of abrupt changes in fluid shear stress (Delta tau) correlates with capillary hydraulic conductivity (Lp). Cultured endothelial cells differentiate between rate of change in and pattern of fluid stimulation; however, neither rate nor pattern sensitivity has been evaluated in individual capillaries. We hypothesized that Lp would be greater following ...
Iwamoto Masako - - 2003
In glomerular hypertension, monocyte chemoattractant protein-1 (MCP-1) has been implicated in glomerulosclerosis progression. High-pressure load and stretch on mesangial cells (MC) are two major effects of increased glomerular pressure. We previously reported that pressure per se could induce MCP-1 expression in cultured MC, suggesting the involvement of glomerular hypertension in ...
Reynolds T - - 2003
The early specification of bioprocesses often has to be achieved with small (tens of millilitres) quantities of process material. If extensive process discovery is to be avoided at pilot or industrial scale, it is necessary that scale-down methods be created that not only examine the conditions of process stages but ...
de Graaff Jurgen C - - 2003
Capillary circulation is delicately regulated by microvascular constriction mechanisms, thereby controlling capillary perfusion and transmural pressure. The influence of posture on capillary flow has been investigated in both diseased and healthy people. However, its influence on capillary pressure has rarely been investigated. We measured capillary pressures in the supine and ...
Ljutić Dragan - - 2003
Arterial hypertension (AH) per se is, together with diabetes mellitus, the most important cause of renal failure and of dialysis in the western world. AH is also a well known consequence of chronic renal disease, and at the same time one of the main factors which causes diabetic and/or non-diabetic ...
Unger Juliane Katharina - - 2003
Capillary membrane filters are devices commonly used for plasmapheresis and recirculating detoxification systems, including plasmaseparation units. Besides clinical trials and case reports, research on plasmafiltration techniques is carried out using in vitro systems. Notably, such hemoperfused in vitro systems require anticoagulation protocols suitable for investigating the clearance performance and hemocompatibility ...
Edgley Amanda J - - 2003
OBJECTIVES: To determine whether 'slow pressor' hypertension from systemic angiotensin (Ang II) infusion was associated with renal vascular structural remodeling of the renal resistance vessels and glomerulus. METHODS: Ang II (4.5-10 ng/kg per min) or vehicle was infused for 10 days. Renal resistance vascular lumen changes were assessed at 10 ...
Kuriki Minoru - - 2003
BACKGROUND: Steroid therapy for IgA nephropathy (IgAN) has been reported to ameliorate the long-term prognosis of IgAN, but its mode of action has not been fully elucidated. In this study, we examined the effect of steroids on glomerular morphological changes in IgAN. METHODS: We examined 16 patients with biopsy-proven IgAN ...
Futrakul Narisa - - 2003
A structural defect of the non-vascular component of a nephron namely vesicoureteric reflex (VUR) can induce injury to the vascular component, which is reflected by the alteration in intrarenal hemodynamics. A mild alteration in intrarenal hemodynamics was observed in grades I-II VUR which revealed (a) mild reductions in renal plasma ...
McDonough Alicia A - - 2003
An acute increase in blood pressure provokes a rapid decrease in proximal tubule salt and water reabsorption that is central to tubuloglomerular feedback regulation of renal blood flow and glomerular filtration rate and contributes to pressure natriuresis. The molecular mechanisms responsible for this critical homeostatic adjustment were studied. When blood ...
Hostetter Thomas H - - 2003
Nearly 70 years ago, the association between reduction in renal mass and subsequent glomerular injury was established. Later the pathologic changes were attributed to adaptive hemodynamic changes in the residual nephrons. This relationship seems to exist in a number of experimental animal species, as well as humans. Among the various ...
Brown Scott A - - 2003
OBJECTIVE: To determine whether the angiotensin converting enzyme inhibitor enalapril would lower systemic arterial and glomerular capillary pressure and reduce the magnitude of renal injury in a canine model of renal insufficiency. ANIMALS: 18 adult dogs that had renal mass reduced by partial nephrectomy. PROCEDURE: After surgical reduction of renal ...
Campbell Ruth - - 2003
BACKGROUND: Proteinuria predicts renal disease progression, and its reduction by angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor antagonists (ARA) is renoprotective. METHODS: In this prospective, randomized, cross-over study of 24 patients with nondiabetic, chronic nephropathies, we compared the effects on proteinuria, renal hemodynamics, and glomerular permselectivity of 8 weeks ...
Sato Y - - 2003
Renal replacement therapy with dialyzers capable of enhanced internal filtration (IF) can be an alternative to standard hemodiafiltration, as it provides convective solute removal comparable to that of hemodiafiltration by a simple procedure. In this study, we clinically evaluated the effect of the hollow fiber length in the dialyzer, a ...
Cullen-McEwen Luise A - - 2003
The loss of one allele for glial cell line-derived neurotrophic factor (GDNF) results in approximately 30% fewer but normal sized glomeruli in young mice. Low nephron number, inherited or acquired, has been linked to increased risk of development of hypertension and renal failure. This study examines whether GDNF heterozygous mice, ...
Martins Alice M C - - 2003
In Brazil, the genus Crotalus is responsible for approximately 1500 cases of snakebite annually. The most common complication in the lethal cases is acute renal failure, although the mechanisms of the damaging effects are not totally understood. In this work, we have examined the renal effects caused by a supernatant ...
LeLorier Jacques - - 2002
BACKGROUND: Selective cyclo-oxygenase (COX)-2 inhibitors (coxibs) produce the beneficial effects of nonsteroidal anti-inflammatory drugs (NSAIDs) while sparing the COX-1-mediated adverse effects on platelets and the gastrointestinal system. However, due to the presence of constitutive COX-2 in the human kidney, coxibs have the same potential for adverse renal effects as traditional ...
Zimanyi Monika A - - 2002
This study investigated the effects of a high-protein diet during pregnancy on nephron endowment and subsequent levels of blood pressure in the offspring. Female WKY rats were fed either a normal (20%, NPD) or a high (54%, HPD) protein diet during pregnancy. Male offspring were paired at birth. At 4 ...
Haltern C - - 2002
Plasmaseparation is a treatment under discussion for critically ill patients, especially in sepsis and multiorgan failure. These patients receive a variety of different fluid substitutes, including hydroxyethylstarch (HES). HES is known to influence rheological properties, but nothing is known about the possible interactions between HES and the plamaseparation procedure. We ...
Wang Angela Yee-Moon - - 2002
BACKGROUND: Left ventricular hypertrophy (LVH) and dialysis adequacy are both important predictors for mortality in dialysis patients. This study evaluated the association between residual renal function (RRF) and the severity of LVH in endstage renal failure (ESRF) patients undergoing long-term continuous ambulatory peritoneal dialysis (CAPD). METHODS: A cross-section study was ...
Krier James D - - 2002
Hypercholesterolemia (HC) is characterized by increased circulating 8-epi-prostaglandin-F(2alpha) (isoprostane), a vasoconstrictor, marker, and mediator of increased oxidative stress, whose vascular effects might be augmented in HC. Anesthetized pigs were studied in vivo with electron beam computed tomography after a 12-wk normal (n = 8) or HC (n = 8) diet. ...
Morikawa Takashi - - 2002
Experimental studies suggest that some long-acting calcium antagonists decrease glomerular hypertension and suppress the progression of nephropathy, but clinical evidence is lacking. To investigate clinically whether a long-acting calcium antagonist, benidipine, lowers glomerular capillary hydraulic pressure via a decrease in efferent arteriolar resistance and decreases proteinuria, we examined hypertensive patients ...
Ataie-Ashtiani Behzad - - 2002
In theories of multiphase flow through porous media, capillary pressure-saturation and relative permeability-saturation curves are assumed to be intrinsic properties of the medium. Moreover, relative permeability is assumed to be a scalar property. However, numerous theoretical and experimental works have shown that these basic assumptions may not be valid. For ...
Ramsey Carla R - - 2002
Renal interstitial hydrostatic pressure (RIHP) is a link between increased arterial BP and natriuresis. The mechanism whereby increases in RIHP inhibits sodium and water transport across the mammalian proximal tubule epithelium may involve changes in flux across the tight junction of the proximal tubule. The purpose of this study was ...
Herrera-Acosta Jaime - - 2002
To study whether prevention of renal injury using the anti-inflammatory drugs pentosan polysulphate (PPS) and mycophenolate mofetil (MMF) is associated with improvement of glomerular haemodynamics, PPS and MMF were compared with losartan. The awake systolic blood pressure (SBP), proteinuria (Uprot) and micropuncture studies were performed 30 days after five-sixths nephrectomy ...
Kiil F - - 2002
To examine whether local myogenic mechanisms account for autoregulation of renal blood flow, a theoretical analysis was undertaken on a model of the pre-glomerular vascular tree consisting of a main and a short, narrow juxtaglomerular segment. At atmospheric extravascular pressure in vitro data are consistent with a relationship r=r0(1 + ...
Kiil F - - 2002
Along the juxtaglomerular segment of the afferent arteriole the luminal pressure p approaches the glomerular capillary pressure of 55-60 mmHg. At such low luminal pressures the myogenic mechanism contracts only if extravascular pressure p(ex) is subatmospheric. According to Poiseuille's formula complete autoregulation requires that blood flow is F=5Kr(0)(4)/Deltax at arterial ...
Gross Volkmar - - 2002
Gene targeting techniques are a revolutionary tool in determining gene function. The mouse is the only mammal in which these methods can be performed. For morphologic and histologic characterization, a broad armamentarium is available for the mouse. However, for functional studies, the 20- to 25-g mouse provides unique challenges. We ...
Toyota Eiji - - 2002
BACKGROUND: The phase difference of coronary arterial and venous flows indicates the importance of intramyocardial capacitance vessels in storing diastolic flow and in discharging volume in systole. However, the anatomic and functional characteristics of the capacitance vessels are unclear. We aimed to clarify those characteristics with their transmural difference by ...
Tanaka Hikaru - - 2002
T-type Ca(2+) channels have properties different from those of the L-type and are involved in cardiac pacemaking and regulation of blood flow, but not in myocardial contraction. Efonidipine is an antihypertensive and antianginal drug with dihydropyridine structure that was recently found to block both L- and T-type Ca(2+) channels. In ...
Brands Michael W - - 2002
1. Hyperglycaemia can lead to hypertension in long- standing diabetes through cumulative effects to cause progressive glomerular injury. However, it is not known how hyperglycaemia directly affects blood pressure control. Moreover, it has been difficult to isolate the actions of hyperglycaemia from other factors that can influence blood pressure. Recent ...
Imig John D - - 2002
Control of glomerular filtration involves sensitive regulation of glomerular filtration pressure over a widely varying range of systemic arterial pressures. This control is exerted through precise adjustments in preglomerular resistance involving numerous activation and feedback mechanisms. Under physiological conditions, these mechanisms succeed in maintaining renal blood flow and glomerular filtration ...
Hansen Henrik P - - 2002
BACKGROUND: The aim of our study was to evaluate the diurnal variation in glomerular filtration rate (GFR), and the potential mechanisms responsible for such variations in GFR and albuminuria in diabetic nephropathy. METHODS: In three 24-hour urine samples, divided into a night- and daytime portion, diurnal variation in albuminuria (ELISA) ...
Bobrova N A - - 2002
A one-dimensional dissipative magnetohydrodynamics code is used to investigate the discharge dynamics of a waveguide for high-intensity laser pulses: the gas-filled capillary discharge waveguide. Simulations are performed for the conditions of a recent experimental measurement of the electron density profile in hydrogen-filled capillaries [D. J. Spence et al., Phys. Rev. ...
Harwood S - - 2001
BACKGROUND: Little is known about the renal handling of endogenous ouabain-like compound (OLC). The aim of this study was to determine the normal renal clearance of OLC and the effect of mild experimental uremia on plasma OLC and its clearance. METHODS: Male Wistar rats were studied 8 weeks after subtotal ...
Suda T - - 2001
BACKGROUND: In glomerular hypertension, mesangial cells (MC) are subjected to at least two physical forces: a high pressure and mechanical stretch. In 5/6 nephrectomized rat, a model of progressive glomerular sclerosis associated with glomerular hypertension, monocyte chemoattractant protein-1 (MCP-1) is expressed in glomeruli, suggesting the possible role of MCP-1 in ...
Bellomo R - - 2001
Septic shock, systemic inflammation and pharmacological vasodilatation are often complicated by systemic hypotension, despite aggressive fluid resuscitation and an increased cardiac output. If the physician wishes to restore arterial pressure (>80-85 mmHg), with the aim of sustaining organ perfusion pressure, the administration of systemic vasopressor agents, such as noradrenaline, becomes ...
Kim S T - - 2001
During hemodiafiltration (HDF) treatment for chronic renal failure patients, replacing large volumes using high-flux membranes with relatively large pores is preferred from the standpoint of enhancing the elimination of large molecules (10 to 50 kd). Aggressive protein-permeable treatment often results in massive leakage of essential albumin, however, which may cause ...
Christensen P K - - 2001
Impaired autoregulation of the glomerular filtration rate (GFR) implies disturbances in the downstream transmission of the systemic blood pressure into the glomerulus, leading to capillary hypertension or hypotension dependent of the level of blood pressure. The impact on renal autoregulation of different antihypertensive drugs in animals has been elucidated, whereas ...
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