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Results 351 - 400 of 858
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Dobbins D E - - 1992
Neurokinin A and B are putative inflammatory mediators. We assessed their ability to alter prenodal lymphatic resistance. Intralymphatic neurokinin A (3.0 x 10(-6), 3.0 x 10(-5) and 3.0 x 10(-4) mol l(-1)) significantly constricted lymphatics at the two highest doses. Preliminary experiments suggested that neurokinin B might dilate lymphatics. To ...
Maron M B - - 1992
We determined whether the solvent drag reflection coefficient (sigma f) for total proteins of a canine perfused left lower lung lobe (LLL) preparation decreases at elevated venous pressures (Pv). We found that sigma f (estimated using the hematocrit-protein technique) remained constant at all Pv's (30-95 mm Hg) evaluated. These results ...
Tsay T T - - 1992
Isotonic, hypotonic, or hypertonic saline was infused in anesthetized rabbits in order to test the effects of osmolality in cerebral vessels on lymph flow. The jugular lymph trunk was cannulated by PE tubing in a headward direction. Either a hypo-(100 mosmol), iso-(310 mosmol), or hypertonic (605 mosmol) NaCl solution was ...
Heyeraas K J - - 1992
The initial vascular reactions during inflammation are vasodilation and increased vessel permeability. Both these basic reactions cause increased pulpal fluid volume. In the dental pulp the inflammatory vascular reactions take place in a rigid enclosed dentin chamber, which to some extent makes the pulp vulnerable. Due to this lack of ...
Ehrhart I C - - 1992
Simultaneous measures of vascular permeability to fluid (capillary filtration coefficient, Kf) and to plasma proteins (solvent drag reflection coefficient, sigma) were obtained over venous pressures (Pv) from 14 to 105 Torr in the isolated ventilated canine lung lobe (n = 70) pump perfused with autologous blood. The sigma was obtained ...
Chen H I - - 1991
Lymph flow transients were studied in a dog paw preparation when venous pressure was elevated by 15 and 25 mmHg. The lymph flow transients showed a very rapid initial increase which then declined to a steady-state value that was one-half the peak lymph flow response for both pressure changes. Lymph ...
Negrini D - - 1991
The parameters describing the permeability of the parietal pleura to liquid and total plasma proteins were measured in five anesthetized adult dogs. Small areas of parietal pleura (approximately 1 cm2) and the underlying endothoracic fascia were exposed through resection of the skin and the intercostal muscles. The portion of the ...
Levick J R - - 1991
The evidence for the functional importance of extravascular Starling pressures now seems overwhelming, and when these terms are taken into account it is difficult to uphold the traditional conception that upstream microvascular filtration is largely matched by a sustained downstream reabsorption. Transient absorption can occur, however, during spontaneous vasomotion cycles, ...
Isago T - - 1991
We estimated the reflection (sigma) and filtration coefficients (Kf) in a chronic sheep lung lymphatic preparation after smoke inhalation. Group I (n = 7) sheep were insufflated with cotton smoke and group II animals (n = 5) with room air. After inhalation injury, the lung lymph flow increased nearly four ...
Morel D R - - 1991
1. Endothelin, a novel vasoconstrictor 21-residue peptide isolated from the supernatant of cultured porcine endothelial cells, has been shown to be increased in plasma in a variety of cardiovascular disease states, including acute myocardial infarction, acute renal failure and essential hypertension. We determined the time course of plasma and pulmonary ...
Dobbins D E - - 1991
Endothelin is a 21 amino acid peptide which is produced by the vascular endothelium and is believed to be the mediator of endothelium-dependent vasoconstriction. In the current study we assessed the ability of synthetic human endothelin-1 to affect prenodal lymphatic vessel contractility in the canine forelimb. Intralymphatic infusion of endothelin ...
Taylor A E - - 1991
A review of the factors that oppose pulmonary edema formation (alveolar flooding) when capillary pressure is elevated are presented for a normal capillary endothelial barrier and for damaged endothelium associated with ischemia/reperfusion in rabbit, rat, and dog lungs. Normally, tissue pressure, the plasma protein osmotic pressure gradient acting across the ...
Drake R E - - 1991
We used a new technique to estimate the pulmonary microvascular membrane reflection coefficient to plasma protein (sigma d) in anesthetized dogs. In five animals we continuously weighed the lower left lung lobe and used a left atrial balloon to increase the pulmonary microvascular pressure (Pc). We determined the relationship between ...
Laine G A - - 1991
We hypothesized that both acute and chronic accumulation of myocardial interstitial edema (extravascular fluid [EVF]) would compromise cardiac function. We also postulated that excess fluid within the myocardial interstitial space would potentiate interstitial fibrosis, thus further compromising function. Dogs were divided into three groups: 1) control, 2) chronic pulmonary hypertensive ...
Mann R - - 1991
We determined if the cardiopulmonary response to endotoxin (LPS) is mediated by bradykinin (BK). Sheep (n = 30) were prepared for chronic study with cardiopulmonary catheters, and chronic lung lymph fistulae. They were divided into the following study groups: A) BK infusion; B) LPS; C) LPS with angiotensin converting enzyme ...
Drake R E - - 1991
Lymphatic vessels are important in draining excess fluid from the abdominal space and preventing ascites. In sheep, diaphragmatic lymph vessels draining the abdominal space run to the caudal mediastinal lymph node and efferent vessels from the node drain into veins in the neck. To estimate the lymph flow response to ...
Nelson S - - 1991
The present study examined reactivity to norepinephrine (NE) and KCl in isolated, suffused blood vessels from the systemic and pulmonary circulations of endotoxin-treated and control sheep. A possible mechanism underlying an endotoxin-induced alteration in vascular reactivity was also investigated. Chronically instrumented sheep were given Escherichia coli endotoxin (1.5 micrograms/kg). Eight ...
De Paulis R - - 1991
Formation of complexes between heparin and protamine (in saline), or heparin, plasma proteins, and protamine (in plasma) was assessed by measurements of light transmission through different test solutions. To examine the formation of these complexes, 125I-labeled protamine was used. Addition of 125I-protamine to plasma or blood resulted in the sedimentation ...
Sweeney T E - - 1991
Convective transport is a critical element in the regulation of steroidogenesis and spermatogenesis in the testis. Steroid hormones are distributed to their target cells within seminiferous tubules via interstitial fluid. The movement of interstitial fluid and lymph, which transports protein hormones and many of the substrates required for spermatogenesis and ...
Drake R E - - 1991
Lymphatic vessels are important in removing excess fluid from the intestines and preventing intestinal edema. In this study we used the relationship between intestinal lymph flow rate (QL) and lymphatic outflow pressure (PO) to analyze the flow from intestinal lymphatics in unanesthetized sheep. We cannulated intestinal lymphatic vessels in six ...
Knox J - - 1991
OBJECTIVE: To determine the effect of a dobutamine infusion on the relationship between oxygen consumption (VO2) and oxygen delivery (DO2) after endotoxin administration, as well as the rate of fluid and protein loss from permeability-injured tissue. METHODS: Unanesthetized adult sheep with lung and soft-tissue lymph fistulas were given 5 micrograms/kg ...
Brackett D J - - 1991
There is evidence that free radical activity may be important in the development of endotoxemia. Dimethyl sulfoxide is a hydroxyl radical scavenger that readily penetrates cell membranes. Using the conscious, instrumented rat this study tests the ability of dimethyl sulfoxide to modify the course of endotoxemia by evaluating cardiovascular, metabolic, ...
Tamari Y - - 1991
The use of a bloodless solution and high pressure to accelerate microporous membrane oxygenator (MMO) failure was investigated. It was hypothesized that albumin acts as a wetting agent, contributing to plasma leakage through the membrane, and that high MMO outlet pressure accelerates the process. Three MMO, B-Bentley BCM-40 (n = ...
Hardie W D - - 1991
To gain a better understanding of the adverse pulmonary response to amphotericin B administration reported in humans, we examined the effects of this agent in the chronically instrumented awake sheep. We measured pulmonary artery and left atrial pressures (Ppa and Pla), lung lymph flow (Qlymph), dynamic lung compliance (Cdyn), resistance ...
Klausner J M - - 1991
Interleukin-2 therapy leads to respiratory dysfunction caused by increased vascular permeability. This study examines the role of oxygen-derived free radicals (OFR). Sheep (n = 6) with chronic lung lymph fistulae were given interleukin-2, 10(5) units/kg, as an intravenous bolus. The mean pulmonary artery pressure rose from 13 to 23 mm ...
Broaddus V C - - 1991
The source of normal pleural liquid is thought to be the systemic circulation of the pleural membranes rather than the pulmonary circulation of the nearby lung. Evidence for a systemic origin comes from the low protein concentration of pleural liquid in adult sheep, which is consistent with protein sieving from ...
Hargreaves M - - 1991
1. The responses of the rapidly adapting receptors (RARs) and the slowly adapting receptors (SARs) of the airways to changes in the Starling forces regulating fluid exchange in the pulmonary extravascular space were investigated in anaesthetized rabbits. The hydrostatic pressure in the pulmonary microvasculature was raised by partial obstruction of ...
Watts F L - - 1991
The effect of the beta-agonist, ritodrine HCl, was studied on cardiac output (CO) and pulmonary lymph flow (QL) in sheep. Increased CO is associated with an increase in pulmonary QL in sheep during exercise. Isoproterenol increases CO but has not been shown to increase pulmonary QL. Ritodrine HCl was chosen ...
Dabney J M - - 1991
Prostaglandins may contribute to the control of lymph flow by affecting lymphatic vessel contractility. We measured the pressure in perfused prenodal lymphatic vessel in the paw of the anesthetized dog as affected by administration of prostaglandins E1, E2, F2 alpha or arachidonic acid. The forelimb was perfused at constant flow ...
Higaki A - - 1990
The effect of hemorrhage and retransfusion on the rhythmic contraction of mesenteric lymphatic vessels was studied in 24 rats, anesthetized with pentobarbital. The rats were divided into four groups according to the amount of blood withdrawn: 0.5ml/100g body weight (BW), 1ml/100g, 2ml/100g, and 2.5ml/100g. Immediately following hemorrhage at the rate ...
Lakshminarayan S - - 1990
We examined the effect of elevating systemic venous pressure on the rate of edema formation in the left lower lobes (LLL) of anesthetized, open-chested dogs. The pulmonary circulation of the LLL was isolated using cannulae in the artery and vein which were attached to blood-filled reservoirs. The LLL was distended ...
Dobbins D E - - 1990
We have previously reported that perfused lymphatic vessels in the canine forelimb constrict in response to increased sympathetic nerve activity or local infusions of endogenous vasoconstrictor substances. In the present study we have assessed the effects of three endogenous vasodilators; acetylcholine, bradykinin and histamine on lymphatic vessel contractility. Each one ...
Allen D D - - 1990
A carbohydrate overload model was used in 8 horses to evaluate Starling forces and hemodynamics of the digit during the prodromal stage of acute laminitis. A pump-perfused extracorporeal digital preparation was used to evaluate blood flow, arterial pressure, venous pressure, capillary pressure, isogravimetric capillary filtration coefficient, osmotic reflection coefficient, and ...
Dobbins D E - - 1990
Platelet activating factor (PAF), a potent vasoactive lipid, may play an important role in the inflammatory process. In this study, we infused PAF intra-arterially to characterize its edematogenic potency in the canine forelimb. We have also assessed the ability of the beta 2-receptor agonist l-terbutaline to block PAF-mediated edema formation. ...
Isago T - - 1990
We devised a technique that permitted elevation of pulmonary pressures in unanesthetized sheep by occluding their pulmonary veins. Using this technique, we raised pulmonary capillary pressure from a baseline of 13.2 +/- 2.2 to 35.3 +/- 5.1 mmHg. This increased lung lymph flow (from 8.8 +/- 2.7 to 53.1 +/- ...
Hunt R J - - 1990
Using a pump-perfused extracorporeal isolated digital preparation, the effects of a 30-minute infusion of either saline solution (control) or endotoxin on equine digital hemodynamics and microvascular function were determined. Digital blood flow and arterial, venous, and capillary pressures were recorded at 15-minute intervals for 150 minutes. From these data, total ...
Zellner P R - - 1990
The most important question that had to be answered from our animal data was whether a significant difference existed between the two groups. It could be observed that the resuscitation with Ringer's lactate did not lead to any increased lymph flow or total transcapillary protein flow in spite of the ...
Sharpe M D - - 1990
Oxidant-induced injury of the pulmonary microvasculature reportedly contributes to an increase in microvascular permeability and pulmonary hypertension, both of which are principal features of acute lung injury (ALI). We tested the hypothesis that antioxidant therapy with 2,3-dihydroxybenzoic acid (DHB), initiated in awake sheep after the development of sepsis-induced ALI, would ...
Drake R E - - 1990
We used lymph flow rate (QL) to lymphatic vessel outflow pressure (Po) relationships to analyze lymphatic flow in five unanesthetized sheep with liver lymphatic cannulas. The olecranon was the zero reference level for pressures. Increases in Po did not change QL until Po exceeded 19 +/- 4 (SD) cmH2O. However, ...
Reed R K - - 1990
Hyaluronan, an important structural component of the interstitial matrix in skin, is found in lymph to be subsequently degraded in lymph nodes and liver. Hyaluronan concentration and flux were measured in prenodal lymph from the hindpaw in six pentobarbital-anesthetized mongrel dogs at normal and increased transvascular fluid flux. Lymph flow ...
Zanaboni P B - - 1990
The effect of cyclooxygenase inhibition in phorbol myristate acetate (PMA)-induced acute lung injury was studied in isolated constant-flow blood-perfused rabbit lungs. PMA caused a 51% increase in pulmonary arterial pressure (localized in the arterial and middle segments as measured by vascular occlusion pressures), a 71% increase in microvascular permeability (measured ...
Roselli R J - - 1990
Lung fluid balance was studied in sheep under the following conditions: 1) unanesthetized, standing in a metabolic cage; 2) anesthetized, in a supine position; 3) 1 h after extracorporeal perfusion; and 4) either 4-6 h after extracorporeal perfusion (i.e., control experiments) or 1.5 h after left atrial pressure was increased ...
Demling R H - - 1990
We studied the first 24-hour lung and systemic physiologic response to a moderate smoke inhalation injury. In addition, we monitored oxidant-induced lipid peroxidation (LP), using malondialdehyde and conjugated dienes. Sixteen adult sheep with lung and soft tissue lymph fistulas were given 20 breaths of smoke while under anesthesia. Eight sheep ...
Parker J C - - 1990
Mechanical ventilation with high peak airway pressures (Paw) has been shown to induce pulmonary edema in animal experiments, but the relative contributions of transvascular filtration pressure and microvascular permeability are unclear. Therefore, we examined the effects of positive-pressure ventilation on two groups of open-chest dogs ventilated for 30 min with ...
Carlton D P - - 1990
To study the effects of inflation pressure and tidal volume (VT) on protein permeability in the neonatal pulmonary microcirculation, we measured lung vascular pressures, blood flow, lymph flow (QL), and concentrations of protein in lymph (L) and plasma (P) of 22 chronically catheterized lambs that received mechanical ventilation at various ...
Negrini D - - 1990
The hydraulic conductivity (Lp) of the parietal pleura was measured in vivo in spontaneously breathing anesthetized dogs in either the supine (n = 8) or the prone (n = 7) position and in an excised portion of the chest wall in which the pleura and its adjacent tissue were intact ...
Bressani R - - 1990
A comparative study of roasting, cooking with and without calcium hydroxide and extrusion cooking on the protein quality of Canavalia was conducted. The results suggested both extrusion and pressure cooking with lime to be equally effective in improving the protein quality of Canavalia and superior to pressure cooking alone and ...
Morse E D - - 1990
Recombinant interleukin-2 (rIL-2) has shown promise in the treatment of patients with advanced cancer. However, toxicity of this therapy remains a major problem with its use in some patients. In this study we examined whether steroids could reduce the adverse cardiopulmonary effects of rIL-2. Seven sheep were surgically prepared with ...
Orr J A - - 1990
Intravenous infusion of HCl has been shown to elicit the release of thromboxane A2 (TxA2) which alters blood pressure and breathing independent of reductions in circulating blood pH. The present experiments were designed to determine if the release of serotonin (5-HT) in the anesthetized cat contributed to cardiorespiratory responses during ...
Elk J R - - 1990
The amount of lymph received by the thoracic duct depends on each contributing organ's ability to produce interstitial fluid and generate a pressure differential moving lymph into the central lymphatic circulation. It has been reported that varying the pressure within the thoracic duct could alter each organ's contribution to thoracic ...
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