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Results 351 - 400 of 1160
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Khiabani H Z - - 2000
OBJECTIVE: factors regulating transcapillary fluid transport were investigated to elucidate the causes of oedema in CLI. MATERIAL: sixteen patients, 6 men and 10 women (mean age of 79+/-10.3 years) with unilateral CLI and peripheral pitting oedema. METHODS: measurements were performed in both limbs. Interstitial fluid was collected by applying blister ...
Woodrow G - - 2000
BACKGROUND: Glucose absorption from glucose-based dialysis fluids limits ultrafiltration from the daytime dwell in automated peritoneal dialysis (APD). Icodextrin may allow greater ultrafiltration during the daytime period in APD, enhancing fluid control. METHODS: A 7.5% icodextrin dialysate was compared with a 2. 27% glucose dialysate for the daytime dwell in ...
Rauch C - - 2000
The dynamics of endocytosis in living K562 cells was investigated after the osmotic pressure of the external medium was decreased and the transmembrane phospholipid number asymmetry was increased. When the external pressure was decreased by a factor of 0.54, a sudden inhibition of endocytosis was observed. Under these conditions, the ...
Scott D - - 2000
Hyaluronan concentration in synovial fluid spans a 20-fold range, from as low as 0.2 mg ml(-1) in synovitis to as high as 4 mg ml(-1) in healthy joints. The aim was to determine the effect of this on fluid drainage from the joint cavity. The study extends the finding of ...
Scott D - - 2000
OBJECTIVE: How is fluid volume regulated in joints? Fluid drainage rate is an important factor, both in normal joints and those with effusions. Hyaluronan and albumin, separately, are known to attenuate drainage, conserving synovial fluid volume in the presence of raised joint pressure. Hyaluronan and albumin normally coexist, however, in ...
Zhang W B - - 2000
To determine the distribution of interstitial fluid pressure (Pi) and volume (Vi), and to relate the distribution of these parameters to the distribution of potential meridians located by measurement of electrical impedance, we measured Pi, extracellular fluid (Ve) and plasma volumes (Vp) in 14 pre-defined skin areas, 2 x 2 ...
Moussy Y - - 2000
Analytical expressions describing convective flow in a continuous arteriovenous hollow fiber hemofilter were developed. In the lumen of the hollow fiber membrane, existing analytical expressions were applied to describe velocity profiles and pressure. For flow in the shell (the extracapillary space separating the fibers), analytical expressions for the radial and ...
Dreger DS - - 2000
Regional distance seismic moment tensor determinations and broadband waveforms of moment magnitude 4.6 to 4.9 earthquakes from a November 1997 Long Valley Caldera swarm, during an inflation episode, display evidence of anomalous seismic radiation characterized by non-double couple (NDC) moment tensors with significant volumetric components. Observed coseismic dilation suggests that ...
Hess S - - 2000
A simple short range repulsive potential (SR), with an even smoother cut off than the Weeks-Chandler-Andersen (WCA)-Lennard-Jones potential, yields practically the same pressure, both in the fluid state and for the fcc solid, when the potential parameters are chosen such that the forces are the same at the distance where ...
Hahn R G - - 2000
OBJECTIVE: In order to control fluid absorption, various approaches are used to reduce intravesical pressure during transurethral resection of the prostate (TURP). With a view to finding a target pressure for such efforts, pressure and fluid absorption were compared in a meta-analysis of four previous studies comprising three different irrigation ...
Geranton F - - 2000
BACKGROUND: Colloid osmotic pressure (COP) plays a major role in transcapillary fluid shift, including in the glomerular capillary. However, COP is generally estimated by quadratic equations derived from total plasma protein and/or albumin concentrations. The aim of this study was to assess the accuracy of such equations, and to determine ...
Wren T A - - 2000
Tendons that wrap around bones often undergo fibrocartilaginous metaplasia. In this paper, we examine the biomechanical causes and consequences of this metaplasia. We propose an adaptation rule in which tissue permeability changes in response to local cyclic hydrostatic pressures associated with physical activity. The proposed rule predicts the development of ...
Hartung J - - 2000
OBJECTIVE: To report our results of the measurement of the amniotic fluid pressure in twin-to-twin transfusion syndrome before and after amniodrainage and the separate measurement in the cavity of the stuck twin and the recipient, respectively, in 2 cases. METHOD: Six patients with severe TTS underwent therapeutic amniodrainage. Amniotic fluid ...
Lintilhac P M - - 2000
In this article we describe a new method for the determination of turgor pressures in living plant cells. Based on the treatment of growing plant cells as thin-walled pressure vessels, we find that pressures can be accurately determined by observing and measuring the area of the contact patch formed when ...
Petrounkina A M - - 2000
The osmotic reactivity of boar spermatozoa during incubation in vitro was studied using a hypo-osmotic swelling test in conjunction with electronic measurement of cell volume. Sperm populations showed fluctuations in both iso-osmotic cell volume and hypo-osmotic volume response that fitted mathematical models for periodicity. Significant differences of frequency and amplitude ...
Soltz M A - - 2000
The objective of this study was to experimentally verify the well-accepted but untested hypothesis that cartilage interstitial fluid pressurizes variously under the action of an applied cyclical stress in confined compression over a range of loading frequencies, contributing significantly to the cartilage dynamic stiffness. Eighteen bovine cartilage cylindrical samples were ...
Gwaltney J M JM - - 2000
Intranasal pressures were measured in adults during nose blowing, sneezing, and coughing and were used for fluid dynamic modeling. Sinus CT scans were performed after instillation of radiopaque contrast medium into the nasopharynx followed by nose blowing, sneezing, and coughing. The mean (+/-SD) maximal intranasal pressure was 66 (+/-14) mm ...
Neuzil CE - - 2000
Osmotic pressures are generated by differences in chemical potential of a solution across a membrane. But whether osmosis can have a significant effect on the pressure of fluids in geological environments has been controversial, because the membrane properties of geological media are poorly understood. 'Anomalous' pressures--large departures from hydrostatic pressure ...
Schumacher J - - 2000
BACKGROUND: The rate of intercompartmental fluid volume changes during hemodialysis (HD) is a major determinant of dialysis-induced hypotension and lacks direct monitoring. The aim of the study was to evaluate the feasibility of tissue thickness (TT) measurement in monitoring the mobilization of interstitial fluids during HD. METHODS: We studied the ...
Vincent J L - - 2000
Fluid management strategies need to be guided by an understanding of the pathophysiologic mechanisms underlying fluid imbalance. In the hypovolaemic patient, reduced circulating blood volume and venous return and, in severe cases, altered tissue perfusion may initiate a cascade of pathophysiologic processes culminating in multiple organ failure. The objectives of ...
Grazi E - - 2000
The contractile system is a highly non-ideal solution. The activities of its components must be determined in order to achieve a meaningful representation of cross-bridge kinetics and of chemio-mechanical transduction. Osmotic techniques may help in this respect. A few examples are presented. Protein osmotic pressure influences cross-bridges by determining (1) ...
Hu X - - 1999
In this paper we quantitatively investigate the hypothesis proposed by Michel (Exp. Physiol. 82, 1-30, 1997) and Weinbaum (Ann. Biomed. Eng. 26, 1-17, 1998) that the Starling forces are determined by the local difference in the hydrostatic and colloid osmotic pressure across the endothelial surface glycocalyx, which we propose is ...
Sandfeldt L - - 1999
BACKGROUND: We compared symptoms and indices of fluid distribution after experimental administration of glycine and mannitol solutions, since these irrigating fluids are sometimes absorbed by the patient during genitourinary surgery. METHODS: Glycine 1.5% and mannitol 3%, both with ethanol 1% added, were given by intravenous infusion at a rate of ...
Parameswaran S - - 1999
Hydraulic conductivity (L), albumin reflection coefficient (sigma), and albumin diffusion coefficient (D) were measured across pig mediastinal pleura. The tissue (7 mm diameter) was bonded between two chambers. Flow (Q) of lactated Ringer solution between the chambers was measured in turn at driving pressures (DeltaP) of 2, 4, and 6 ...
Comstock J P - - 1999
A critique of Martin Canny's theory of water transport supported by tissue pressure is given with reference to basic principles of cellular water relations and biomechanics. It is shown that the application of tissue pressure in Canny's theory is neither internally consistent nor compatible with basic biophysics. Canny's translation of ...
Baraniuk J N - - 1999
Hypertonic saline (HTS) induces bronchoconstriction. Potential mechanisms were evaluated in a human nasal provocation model. Aliquots of normal saline (1 x NS, 100 microliters) and higher concentrations (3 x NS, 6 x NS, 12 x NS, 24 x NS) were sprayed into one nostril at 5-min intervals. Lavage fluids were ...
Jaccoby S - - 1999
In chickens, hyperosmolality and hemorrhage increase hypothalamic vasotocin (AVT) gene expression and stimulate the secretion of AVT from the posterior pituitary gland. In this study, c-fos expression was used to identify areas in the forebrain and brainstem of the domestic chicken that are activated following acute osmotic stress and hemorrhage-induced ...
Hardebeck JL - - 1999
The stress orientation signature of weak faults containing high-pressure fluids has been observed for segments of the San Andreas fault system in southern California. The inferred lithostatic fluid pressures extend into the surrounding relatively intact rock in a zone scaling with the width of the interseismic strain accumulation. Repeated strain-related ...
Fasanmade A A - - 1999
To determine the effect of diuretic therapy on osmotic fragility of red blood cells of hypertensive patients, 25 hypertensive and 15 normotensive subjects were followed up for 12 weeks. Osmotic fragility of erythrocytes of the hypertensive subjects were determined before treatment and at 6 weeks and 12 weeks after the ...
Loucks RR - - 1999
Dissolved gold contents in chloride brines that were experimentally saturated with gold, magnetite, iron sulfides, orthoclase, and muscovite at 550 degrees to 725 degrees C and 100 to 400 megapascals are reported here. Microsamples of the fluid were isolated at the experimental temperature and pressure as fluid inclusions in quartz. ...
Nifong T P - - 1999
Line pressure changes are inherent to apheresis procedures, although little work has been done to determine their physical basis. We developed a mathematical model in which fluid pressure within apheresis tubing is primarily dependent upon viscosity and hematocrit (HCT). Return line flow rates and pressures during plasma collections for peripheral ...
Brunner A - - 1999
PURPOSE: To measure changes in pH as well as osmotic pressure in aqueous pores and cavities inside biodegradable microspheres made from polymers such as poly(D,L-lactic acid) (PLA) and poly(D,L-lactic acid -co- glycolic acid) (PLGA). METHODS: The internal osmotic pressure inside eroding PLA microspheres was analyzed with differential scanning calorimetry (DSC) ...
Gehring H - - 1999
BACKGROUND: The absorption of irrigation fluid during transurethral resection of the prostate (TURP) is determined primarily by hydrostatic pressure in the bladder and prostatic venous pressure. In comparison to spontaneously breathing patients, patients undergoing mechanical ventilation with positive pressure have a raised central venous pressure and a reduced venous return, ...
Bruner J P - - 1999
OBJECTIVE: To measure acute and chronic changes in the placenta and amniotic fluid associated with performance of decompression amniocentesis in pregnancies with the twin oligohydramnios-polyhydramnios sequence (TOPS). METHODS: Amniotic fluid pressures, placental thickness, placental perfusion, and amniotic fluid volumes were measured in each sac of a monochorionic diamniotic twin gestation ...
Prior F G - - 1999
Several conflicting theories have been proposed to explain the development of oedema. Pulse reverse osmosis (PRO) suggests that oedema occurs when the mean pulse capillary pressure exceeds the osmotic gradient between the plasma and the interstitial fluid. In order to test this concept mean arterial blood pressures and colloid osmotic ...
Hunt WJ - - 1999
Osmotic pressure and elastic moduli of bimodal suspensions of particles experiencing long-range, soft repulsions were measured. At fixed osmotic pressure, the total suspension volume fraction, &phi;, varies linearly as the mixing ratio &phi;l/&phi; is increased from 0 to 1. Here &phi;l is the volume fraction of large particles based on ...
Zakaria E R - - 1999
Fluid loss from the peritoneal cavity to surrounding tissue varies directly with intraperitoneal hydrostatic pressure (Pip). According to Darcy's law [Q = -KA(dPif/dx)], fluid flux (Q) across a cross-sectional area (A) of tissue will increase with an increase in either hydraulic conductivity (K) or the interstitial fluid hydrostatic pressure gradient ...
Mow V C - - 1999
OBJECTIVE: (1) Provide an overview of the biomechanical factors that are required to analyze and interpret biological data from explant experiments; (2) Present a description of some of the mechano-electrochemical events which occur in cartilage explants during loading. DESIGN: A thorough and provocative discussion on the effects of loading on ...
Zhang W - - 1999
The impedance on the pericardium merdian near Quze (P3) and control points in 12 cases was measured by a four electrodes impedance instrument. The amplitude of impedance was recorded before, during and after needling the Neiguan. The result showed that the mean impedance on the meridian and control points before ...
Flessner M F - - 1999
Experiments in animals and in humans have shown that fluid loss from the peritoneal cavity to the body increases with large increments in the intraperitoneal hydrostatic pressure (IPP). We have demonstrated previously that much of this fluid loss occurs to the abdominal wall and is driven by the hydrostatic pressure ...
Heyeraas K J - - 1999
Tissue pressure is the hydrostatic pressure in the interstitial fluid which surrounds the pulpal cells. This pressure outside the vessels is normally considerably lower than the blood pressure inside the vessels. The dental pulp has a relatively low interstitial compliance due to its enclosure between rigid dentin walls. Accordingly, even ...
Lin J - - 1999
The time length required for the adaptation of AFP-27 hybridoma cells to high osmotic pressure and the effect of a gradual increase of osmotic pressure on monoclonal antibody production were investigated. When the cells were subjected to an increase of osmotic pressure from 300 mOsmol kg-1 to 366 mOsmol kg- ...
Lin J - - 1999
The effect of high osmotic pressure on the flux changes of two energy metabolisms from glucose and glutamine by AFP-27 hybridoma cells producing monoclonal antibody (MAb) was investigated in batch cultures at various osmotic pressures in the range from 300 to 424 mOsmol/kg. The specific production rate of MAb (q(MAb)) ...
Coleman P J - - 1999
1. The effect of a rooster comb hyaluronan (3.6-4.0 g l-1) of similar chain length to rabbit synovial fluid hyaluronan, on the trans-synovial escape of fluid from the joint cavity in the steady state ( 8d s) was studied in 29 rabbit knees at controlled intra-articular pressures (Pj). 2. Rooster ...
Lai W M - - 1998
Osmotic pressure loading of articular cartilage has been customarily invoked to be equivalent to mechanical loading. In the literature, this equivalence is defined by the amount of water squeezed from the tissue, i.e. if the amount of water content lost by these two modes of loading are the same, it ...
Alonso M I - - 1998
Following neurulation, the anterior end of the neural tube undergoes a dramatic increase in size due mainly to the enlarging of the brain cavity. This cavity is filled with so-called neural tube fluid (NTF), whose positive pressure has been shown to play a key role in brain morphogenesis. This fluid ...
Gaffar A - - 1998
Dentinal hypersensitivity results when stimulation causes the fluid in open dentinal tubules to undergo pressure changes, which activates mechanoreceptor nerves and results in pain. Treatment with fluoride varnish forms a protective layer of calcium fluoride that prevents this fluid flow, thereby reducing dentinal sensitivity.
Ehrlich S - - 1998
We used equilibrium dialysis to measure the osmotic pressure of chondroitin sulphate (CS) solutions as a function of their concentration and fixed charge density (FCD) and the ionic strength and composition of the solution. Osmotic pressure varied nonlinearly with the concentration of chondroitin sulphate and in 0.15 M NaCl at ...
Soltz M A - - 1998
Interstitial fluid pressurization has long been hypothesized to play a fundamental role in the load support mechanism and frictional response of articular cartilage. However, to date, few experimental studies have been performed to verify this hypothesis from direct measurements. The first objective of this study was to investigate experimentally the ...
Semb K A - - 1998
The aim of our study was to elucidate whether the fluid retention syndrome induced by docetaxel is caused by capillary protein leakage or by other mechanisms. Twenty-four patients with advanced or metastatic non-small-cell lung cancer (NSCLC; 23 patients) or metastatic head and neck cancer (one patient) were included on this ...
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