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Results 401 - 450 of 1155
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Del Fabbro M - - 1998
Gingival hydraulic interstitial pressure was measured with glass micropipettes in 18 anesthetized rabbits at the level of the free gingiva, attached gingiva and oral mucosa facing the incisors and molar teeth. Samples of gingival interstitial tissue fluid were also collected by inserting nylon wicks in the subepithelial layer of the ...
Berg A - - 1998
Interstitial fluid pressure (Pif) has been studied in rat nasal mucosa during early inflammatory reactions induced by dextran anaphylaxis and local application of histamine. Pif was measured by using sharpened micropipettes connected to a servo-controlled counterpressure system. Access to the nasal mucosa was obtained from the facial side of the ...
Lambermont B - - 1998
BACKGROUND: Pressure measuring systems using fluid-filled catheters can result in the recording of distorted pressure waveforms. It results in phase delay, overestimation of systolic and, to a lesser extent, of diastolic pressure. We designed and evaluated a method to correct this pressure waveform distortion using an appropriate transfer equation obtained ...
Tokuyama T - - 1998
BACKGROUND: In a previous case report, it was shown that an increase in plasma colloid osmotic pressure induced by the removal of fluid during haemodialysis was instrumental in decreasing intraocular pressure. The relation between changes in intraocular pressure, plasma osmolarity, plasma colloid osmotic pressure, and body weight before and after ...
Aspenberg P - - 1998
Distal migration of the femoral component of a total hip replacement by as little as 0.33 mm during the first 6 postoperative months is predictive of the need for revision many years later. Because the fate of the prostheses is defined so early, it is unlikely that wear particles initiate ...
Lind BK - - 1998
Objective: To determine, and confirm, the frequency of extramembranous placement of intrauterine pressure catheters.Methods: It is estimated that 15% of all deliveries in the United States (600,000 deliveries/year) receive intrauterine pressure catheters (IUPCs). This study quantifies the frequency of inadvertently placing IUPCs between the chorioamnionic membranes and the myometrium. An ...
Poolman B - - 1998
In their natural habitats, microorganisms are often exposed to osmolality changes in the environment. The osmotic stress must be sensed and converted into an activity change of specific enzymes and transport proteins and/or it must trigger their synthesis such that the osmotic imbalance can be rapidly restored. On the basis ...
Del Fabbro M - - 1998
Knowledge of pleural liquid pressure (Pliq) and composition is crucial for studies concerning intrapleural fluid dynamics, and pleural fluid turnover. We measured Pliq at intercostal and costal levels in anaesthetized spontaneously breathing rabbits using a minimally invasive method that assures a long-lasting hydraulic continuity between the pleural liquid and the ...
Coleman P J - - 1998
1. The hydraulic resistance of the synovial lining to fluid outflow from a joint cavity (Qs) is important for the retention of intra-articular lubricant. The resistance has been attributed in part to extracellular glycosaminoglycans, including hyaluronan and chondroitin sulphates. Increased permeability in joints infused with testicular hyaluronidase, which digests both ...
Odar-Cederlöf I - - 1998
Hypertension often occurs with fluid overload. The most common mechanism is considered to be mediated by increased cardiac output. Hemodialysis (HD) patients frequently have large amounts of fluid overload. Neuropeptide Y (NPY) is activated by stress and contributes to hypertension and heart failure. We speculated that NPY may be released ...
Roberts J S - - 1998
Colloid solutions have been developed and used over the past 70 years as expanders of the intravascular space, based on an understanding of Starling's law. Increasing osmotic pressure with colloidal products has remained an attractive theoretical premise for volume resuscitation. Indeed, colloids have been shown to increase osmotic pressure in ...
Wagner J G - - 1998
OBJECTIVE: To compare thermodilution right ventricular end-diastolic volume index (RVEDVI) and pulmonary artery occlusion pressure (Ppao) as predictors of the hemodynamic response to a fluid challenge. DESIGN: Prospective cohort study. SETTING: Medical ICU of a university-affiliated county hospital and medical-surgical ICU of a community hospital. PATIENTS: Twenty-five critically ill patients ...
Basser P J - - 1998
We have used an isotropic osmotic stress technique to assess the swelling pressures of human articular cartilage over a wide range of hydrations in order to determine from these measurements, for the first time, the tensile stress in the collagen network, Pc, as a function of hydration. Osmotic stress was ...
Sleeman B D - - 1998
In this paper we propose a modification to a model of R. K. Jain and L. T. Baxter used to describe fluid transport in vascularized tumours. The model predicts high interstitial pressure in the interior of the tumour together with a rapid decrease in pressure to its periphery in agreement ...
Karch J M - - 1998
The change in aortic blood density in an in vivo rabbit preparation was measured to assess fluid movement at the pulmonary capillaries caused by infusion of hypertonic solution (NaCl, urea, glucose, sucrose, or raffinose in isotonic saline) into the vena cava over 20 s. The hypertonic disturbance increased the plasma ...
Bartels C - - 1998
BACKGROUND: The colloid osmotic pressure (COP) is not routinely assessed during pediatric heart surgery. Two cases of unrecognized hyperoncotic states associated with renal failure have been observed after pediatric heart surgery. We studied the hypothesis that the COP cannot be estimated from the total plasma protein (TPP) or albumin level. ...
Tølløfsrud S - - 1998
BACKGROUND: Extracorporeal circulation induces increased capillary permeability with fluid leakage into the interstitial space, resulting in positive fluid balance and intravascular hypovolaemia. Hypertonic saline 75 mg.ml-1 in dextran 70, 60 mg.ml-1 (HSD) seems to be of benefit in patients with impaired perfusion. The purpose of the study was to investigate ...
van der Vis H - - 1998
Fluctuating high fluid pressures have been reported in pseudojoints after total hip arthroplasty, and may be present throughout the effective joint space. When the pressure extends locally to the bone implant interface, we hypothesized that it might have led to bone resorption. We developed an experimental implant model to study ...
Lu Y M - - 1998
A viscoelastic finite element model of a L2-L3 motion segment was constructed and used to study: (1) the behavior of the intervertebral disc with different amounts of nucleus fluid loss; and (2) the effect of different rates of fluid loss on the viscoelastic behavior of the disc. The results indicate ...
Adhikary G S - - 1998
We describe a case where massive air embolism occurred while infusing fluid under pressure with a pressurized infusion system, with fluid bags which contained volumes of air from the manufacturer. We suggest that anesthesiologists be meticulous in de-airing the infusion bag before connecting it to the intravenous infusion system. Also, ...
Berg A - - 1998
Acute inflammation in skin is accompanied by increased negativity of interstitial fluid pressure (PIF), which will increase capillary fluid filtration and thereby potentiate edema formation. A series of studies indicates that the connective tissue cells in rat dermis are involved in the control of PIF and mediate this response. The ...
Tølløfsrud S - - 1998
BACKGROUND: Hypertonic saline (HS) is increasingly used for fluid resuscitation in hypovolaemic patients. Although the effects of HS have been investigated in animal models, controlled studies in healthy human individuals are few. AIM: The effects of i.v. hypertonic saline 75 mg.ml-1 in dextran 70, 60 mg.ml-1 (HSD) infusion on fluid ...
MacPhee P J - - 1998
1. We have investigated the potential contribution of medullary interstitial oncotic pressure to the net balance of forces influencing fluid movement through the walls of the ascending vasa recta (AVR) in the exposed papillae of 2-week-old Sprague-Dawley rats. 2. Using a capillary zone electrophoresis (CZE) assay, hyaluronan (HA) concentrations were ...
Diskin C J - - 1998
Over 170 years after Richard Bright and a century after Ernest H. Starling, the development, location, and severity of edema in patients with renal impairment continue to baffle the predictions of most nephrologists. While much of the phenomenon can be explained by levels of serum proteins, or hydrostatic pressures, there ...
Parameswaran S - - 1998
OBJECTIVE: To measure the hydraulic conductivity and reflection coefficient for albumin, as defined by the Starling equation, in rabbit mesentery. METHODS: A section of rabbit mesentery was fixed between two chambers filled with lactated Ringer solution. Flow (Q) of Ringer solution was measured across the mesentery at driving pressures (delta ...
Aukland K - - 1997
Mechanical compression of cartilage and tendon has been shown to expel fluid both from collagen fibrils and from the extrafibrillar space. As reported previously, albumin (Alb) concentration and colloid osmotic pressure in tendon fluid (TF) expelled by repeated centrifugations fell progressively at increasing centrifugation force (G = 600, 2,400, and ...
Zakaria el-R - - 1997
We and others have shown that the loss of fluid and macromolecules from the peritoneal cavity is directly dependent on intraperitoneal hydrostatic pressure (Pip). Measurements of the interstitial pressure gradient in the abdominal wall demonstrated minimal change when Pip was increased from 0 to 8 mmHg. Because flow through tissue ...
Chen J Y - - 1997
We introduce a new device and a new technique that facilitate the clearance of postvitrectomy vitreous hemorrhage. We have developed a volume homeostatic fluid-fluid exchanger--Chen's Infusion/Aspiration (Chen's I/A) device. Due to reciprocal synchronized hydraulic action, Chen's I/A provides simultaneous infusion and aspiration of fluid of equal amounts. Therefore, it can ...
Stahlberg R - - 1997
The positive xylem pressure (Px) in cucumber hypocotyls is a direct extension of root pressure and therefore depends on the root environment. Solutions of the electrolyte KCl (0-10 osm) reduced the hypocotyl Px transiently (biphasic response), while the Px reduction by mannitol solutions was sustained. The amplitudes of the induced ...
Stewart R H - - 1997
Myocardial edema formation, which has been shown to compromise cardiac function, and increased epicardial transudation (pericardial effusion) have been shown to occur after elevation of myocardial venous and lymphatic outflow pressures. The purposes of this study were to estimate the hydraulic conductance and osmotic reflection coefficient for the epicardium and ...
Rivas L J - - 1997
OBJECTIVE: To investigate the effect of i.v. administration of fluids on the furosemide-induced reduction in right atrial pressure (RAP) and relative change in blood volume (BV) of splenectomized mares. ANIMALS: 5 splenectomized mares. PROCEDURE: RAP was measured by use of a micromanometer placed in the right atrium. Jugular venous blood ...
Bert J L - - 1997
The relationship between tissue hydrostatic pressure and fluid content is an important determinant of the response of the microvascular exchange system to perturbations. However, only a limited number of studies relating these parameters have been reported. To add to this body of information, fully swollen rat dermis in vitro was ...
Hauck M L - - 1997
Solid tumours have an elevated interstitial fluid pressure (IFP) due to the lack of normal lymphatics, increased permeability of tumour vasculature and an expanding cell population within a potentially limited space. This elevated IFP has been proposed to be an important barrier to the delivery of drugs and marcromolecules. We ...
Camps J - - 1997
The purpose of this study was to evaluate the effect of applied pressure and measurement time on the in vitro measurement of hydraulic conductance of human dentine. Dentine slices were prepared from 50 third molars. Water was forced through the slices under a constant hydrostatic pressure. Five pressures were tested: ...
Callahan M F - - 1997
Sinoaortic baroreceptor denervation (SAD) results in increased osmotically induced secretion of vasopressin (VP) and oxytocin (OT) and increased cardiovascular responses to many centrally acting pressor agents. Studies were conducted to determine whether SAD increases the cardiovascular and endocrine responses to direct and peripheral osmotic stimulation of the supraoptic nucleus (SON). ...
Bert J - - 1997
A validated mathematical model of microvascular exchange in thermally injured humans has been used to predict the consequences of different forms of resuscitation and potential modes of action of pharmaceuticals on the distribution and transport of fluid and macromolecules in the body. Specially, for 10 and/or 50 per cent burn ...
Beyer R - - 1997
We have compared 6% hydroxyethyl starch (HES 200/0.5) with 3% modified fluid gelatin (MFG) for volume replacement in major orthopaedic surgery and studied the effects on haemodynamic state, colloid osmotic pressure, blood clotting and plasma homeostasis. Using a controlled, randomized, single-blind clinical design, we studied 46 consecutive patients undergoing major ...
Ijsselstijn H - - 1997
Vasoactive prostanoids may be involved in persistent pulmonary hypertension (PPH) in infants with a congenital diaphragmatic hernia (CDH). We hypothesized that increased levels of prostanoids in bronchoalveolar lavage (BAL) fluid would predict clinical outcome. We measured the concentrations of 6-keto-prostaglandin F(1alpha) (6-keto-PGF(1alpha)), thromboxane B(2) (TxB(2)), protein, albumin, total cell count, ...
Hahn R G - - 1996
Ethanol monitoring is a fairly new method of assessing fluid absorption during transurethral resection of the prostate (TURP). By using an irrigating fluid containing a trace amount of ethanol, the absorption can be measured by expired-breath tests. We describe a TURP in which large-scale absorption of irrigating fluid occurred despite ...
Wolgast M - - 1996
It is suggested that the glomerular capillary membrane constitutes a flexible gel, where negative charges fixed to the matrix of the membrane account for the maintenance of its integrity. In this model, the hydrostatic pressure throughout the membrane is assumed to equal the glomerular capillary pressure. Pglom. of 56.7 mmHg. ...
Gerzer R - - 1996
Recent observations from space missions indicate that weightlessness does not induce an increase in diuresis and natriuresis in astronauts. Rather, both oral fluid and sodium intake as well as renal fluid and sodium output appear reduced compared with the preflight condition. In addition, influences of reduced energy intake may be ...
Price F M - - 1996
1. When intra-articular pressure is raised to pathological values (> 9 cmH2O) by saline, the hydraulic conductance of the synovial lining increases manyfold. The increase at 25 cmH2O is only partially accounted for by stretching of the tissue and has been ascribed to washout and/or dilution of interstitial matrix biopolymers. ...
Mitamura Y - - 1996
It is known that deoxygenated blood is paramagnetic. A ferrofluidic actuator for an implantable artificial heart has been studied. The magnetic fluid consists of ferromagnetic magnetite particles (10 nm). If artificial cells encapsulating ferromagnetic particles are mixed in blood, the circulation is maintained by applying a magnetic field to the ...
Steurer J - - 1996
Voluntary hyperventilation (HV) provokes hemoconcentration due to a loss of fluid from the intravascular space. In 10 healthy male volunteers the hypothesis was tested whether HV increases transcapillary fluid shift into the interstitial compartment. For this purpose, fluorescent light intensity (FLI) alterations after intravenous injection of sodium fluorescein (Na fluorescein) ...
Prior F G - - 1996
Pulse reverse osmosis (1) is a new theory of fluid balance and exchange which suggests that the mean blood pressure and osmotic gradient control fluid balance and that the pulse controls fluid exchange. In vitro testing has confirmed some of the physico chemical principles underlying the theory (2). The hypothesis ...
Denton D A - - 1996
The progression of animal life from the paleozoic ocean to rivers and diverse econiches on the planet's surface, as well as the subsequent reinvasion of the ocean, involved many different stresses on ionic pattern, osmotic pressure, and volume of the extracellular fluid bathing body cells. The relatively constant ionic pattern ...
Olsson J - - 1996
OBJECTIVE: Absorption of irrigating fluid may occur through severed blood vessels during endometrial resection. We studied whether irrigating fluid can also be absorbed through the undamaged uterus. PARTICIPANTS: We studied 25 women, aged 28-46 years (mean 38 years), who underwent elective laparoscopic sterilisation under general anaesthesia. INTERVENTIONS: In 15 women ...
Negrini D - - 1996
In anesthetized adult rabbits, pulmonary perivascular interstitial pressure (P(ip)), measured by micropuncture technique with intact pleural space, averaged -10.5 +/- 1.9 (SD) cmH2O in control conditions, with a wet-to-dry lung weight ratio (W/D) of 4.8 +/- 0.2. Saline infusion (120 ml i.v. over 120 min) induced interstitial edema, increasing P(ip) ...
Madden T R - - 1996
Earthquake zones in the upper crust are usually more conductive than the surrounding rocks, and electrical geophysical measurements can be used to map these zones. Magnetotelluric (MT) measurements across fault zones that are parallel to the coast and not too far away can also give some important information about the ...
Daviskas E - - 1996
We have previously shown that mucociliary clearance (MCC) decreased during and increased after isocapnic hyperventilation (ISH) with dry air, both in asthmatic and healthy subjects. Inhaled frusemide, an inhibitor of the Na+/K+/2Cl- and NaCl co-transporters on the basolateral membrane of the epithelial cell, prevents the airway narrowing provoked by ISH ...
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