Search Results
Results 451 - 500 of 615
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Norman M - - 1991
The reactivities of neonatal and adult microcirculation have been studied and compared. The cutaneous reactive hyperemia after 1 and 4 min of arterial occlusion (AO) was measured with a laser-Doppler fluxmeter in 21 healthy neonates and 10 adults. Local skin temperature, mean arterial blood pressure (MAP), and skin prick hematocrit ...
Sun B - - 1991
We applied a new ventilator-multi-plethysmograph system to evaluate the effect of surfactant replacement in newborn rabbits under well controlled, nearly physiological conditions characterized by normal ECG and adequate PCO2 in right ventricular heart blood obtained at the end of the experiment. Up to 10 animals were ventilated in parallel with ...
Osanai K - - 1991
We investigated whether alveolar surface force increased and participated in the lung pressure-volume relationship in bleomycin-induced pulmonary fibrosis in hamsters and, if so, whether lung surfactant was hampered in the lungs. On the air-filled pressure-volume curve, decreases of lung volume from control level were significantly higher at 3-8 cmH2O pressure ...
Kinsella J P - - 1991
We studied the hemodynamic consequences during the first 24 h of life in premature baboons (140 d) with hyaline membrane disease that were treated with high-frequency oscillatory ventilation (HFOV) or conventional intermittent mandatory ventilation (IMV). Cardiac output and organ blood flow were measured at three time-points using the radiolabeled microsphere ...
Ruef P - - 1991
Volume and deformability of blood cells are important determinants of the microcirculation. Leukocytes are larger and considerably less deformable than erythrocytes. In our study, volume and deformability of polymorphonuclear neutrophils (PMN), lymphocytes, and monocytes in adults and full-term neonates were studied by means of a micropipette system. Neonatal immature granulocytes ...
Lewis J F - - 1991
To evaluate the potential for aerosolized surfactant treatments of surfactant deficiency, twin lamb fetuses were delivered at 130-132 days gestational age and received nebulized natural surfactant (Neb NS), nebulized Survanta (Neb Surv), tracheally instilled natural surfactant (Inst NS), or nebulized saline (Neb Saline). Neb NS and Neb Surv groups had ...
Widjaja B - - 1991
Substitution of surfactant in immature lungs has two functional targets: the reduction of the overall alveolar surface tension and the mechanical stabilization of the system of alveoli having different diameters. Indeed, the lowering of the surface tension facilitates the inflation of the lungs, but according to Laplace's law small and ...
Winter I - - 1991
Adult rabbit lung surfactant was radioactively labelled with [3H]palmitate and isolated by centrifugation. This material was instilled into the trachea of fetal rabbits prematurely delivered on the 27th gestational day. A similar preparation of unlabelled surfactant was used to measure the effects on pressure-volume characteristics in lungs of 27th day ...
Collins J F - - 1991
The adult respiratory distress syndrome is a major cause of morbidity and mortality in critical care patients. Lung injury in this syndrome is frequently associated with lung infection. The combined insults result in an influx of neutrophils and damage to the pulmonary epithelium. We investigated whether active neutrophil elastolytic activity ...
Davis J M - - 1991
In order to differentiate the effects of hyperoxia and barotrauma in the pathogenesis of acute neonatal lung injury, piglets were either hyperventilated (Paco2, 15-20 torr) for 48 hours with 100% oxygen (Group I), hyperventilated with 21% oxygen (Group II), normally ventilated (Paco2, 40-45 torr) with 100% oxygen (Group III), or ...
Lamm W J - - 1990
We tested the hypothesis that surfactant replacement would be beneficial in the acid-aspiration model of acute lung injury. HCl (0.1 N, 2 ml/kg) was injected into the trachea of excised rabbit lungs (n = 8). Control lungs (n = 4) had no intervention. All were perfused with Tyrode's solution mixed ...
Yamada T - - 1990
Surfactant protein-A (SP-A) isolated from cow surfactant was added to organic solvent extracts of natural bovine surfactant or of Survanta (Abbott Laboratories), and dynamic compliances and pressure-volume curves were measured in rabbits with a gestational age of 27 days. Organic solvent extracts of natural surfactant and Survanta significantly improved dynamic ...
Hall S B - - 1990
To determine whether acute fatty acid lung injury impairs pulmonary surfactant function, we studied anesthetized ventilated rabbits given oleic acid (55 mg/kg iv, n = 11) or an equivalent volume of saline (n = 8). Measurements of pulmonary mechanics indicated a decrease in dynamic compliance within 5 min of injury ...
Nieman G - - 1990
The effect of high alveolar surface tension on alveolar epithelial permeability was studied in anesthetized closed-chest mongrel dogs. Alveolar surface tension was elevated by displacement of pulmonary surfactant from the alveolar hypophase by the aerosolized detergent dioctyl sodium sulfosuccinate (OT). After measurement of baseline hemodynamics, arterial blood gases, and airway ...
Yamada T - - 1990
Surfactant isolated from adult rabbits was separated into large aggregate forms (LA) and small aggregate forms (SA) by centrifugation at 40,000 x g. LA contain SP-A and the surfactant lipophilic proteins SP-B and SP-C and are surface-active in vitro, whereas SA lack the surfactant proteins and have poor surface properties. ...
Davis J M - - 1990
To assess the short-term effects of high-frequency jet ventilation (HFJV) on the neonatal lung, 28 newborn piglets were studied. Nine piglets were unventilated except during brief pulmonary measurements, nine animals were conventionally ventilated (arterial CO2 tension 35-45 torr, arterial O2 tension 70-80 torr) for 4 h, and 10 piglets were ...
Anzueto A - - 1990
Adult baboons (Papio sp.; 8-12 kg) were anesthesized with sodium pentobarbital (20 mg/kg iv). The animals were instrumented for measurement of mean blood pressure (MBP), pulmonary artery pressure (PAP), ECG, arterial and mixed venous blood gases, lung volumes, lung pressures, and efferent phrenic nerve activity. Bronchoalveolar lavage (BAL) was performed. ...
Horiuchi T - - 1990
Administration of bleomycin to animals results in an alteration of the pressure-volume relationship of the lungs with an increased elastic recoil at any given volume. We sought to evaluate the relative importance of surface forces to elastic recoil by comparing the differences between the air and saline pressure-volume curves. The ...
Oetomo S B - - 1990
The effect of exogenous surfactant on endogenous surfactant metabolism was evaluated using a single-lobe treatment strategy to compare effects of treated with untreated lung within the same rabbit. Natural rabbit surfactant, Survanta, or 0.45% NaCl was injected into the left main stem bronchus by use of a Swan-Ganz catheter. Radio-labeled ...
al-Meshal M A - - 1990
Two different formulations of phenylbutazone, one made to contain 0.5% w/v Brij 96 and the other without surfactant, were prepared by conventional crystallization and compressed to tablets by direct compression using a single punch tabletting machine fitted with 3 mm punches. The relative bioavailability of phenylbutazone was determined in Newzealand ...
Peterson B T - - 1990
We replaced the standard serial bronchoalveolar lavage technique with a new "rewash" lavage procedure to allow estimation of the volume and protein concentration of the epithelial lining fluid (ELF) in anesthetized sheep. A bronchoscope 6.0 mm in diameter wedged in an airway was used to lavage a segment of lung ...
Gosselin A M - - 1990
We tested the cardiovascular actions of the surfactant Pluronic F68 by infusing it into anesthetized dogs, in doses approximating those which would be received when Fluosol-DA were used to resuscitate moderate or severe hemorrhage (0.66 and 1.11 g/Kg). In order to alleviate the reactions to Pluronic, the surfactant was purified ...
Kamitsuka M D - - 1990
We studied healthy and saline lavaged rabbits during high frequency oscillatory ventilation to determine what combination of frequency (f), tidal volume (Vt), and mean airway pressure (Paw) produced the lowest peak-to-peak alveolar pressure amplitude (Palv) and physiologic blood gas tensions. Sinusoidal volume changes were delivered through a tracheostomy by a ...
Petty T L - - 1990
The acute respiratory distress syndrome (ARDS) is a common clinical catastrophe following acute lung injury. A multiplicity of clinical states can lead to ARDS. A new classification system has been proposed to deal with associated organ system failure and varying degrees of acute lung injury. ARDS is a permeability and ...
Noack G - - 1990
Immature newborn rabbits with a gestational age of 27 days were paralyzed and kept in body plethysmographs. They were ventilated for 10 min with a tidal volume of approximately 10 ml/kg, with or without previous surfactant treatment via the airways. Tidal volumes and flow were recorded with a pneumotachograph connected ...
Oyarzún M J - - 1989
To determine whether atelectasis might modify lung surfactant, we injected N2 into the right pleural space of adult rabbits. Daily, under sedation, pleural gas volume and pressure were measured and adjusted to 20 ml/kg and 0 to +2 cm H2O with N2. On the sixth day, pHa, PaCO2, PaO2, and ...
Byrick R J - - 1989
To determine the efficacy of high-volume, high-pressure pulsatile lavage in the prevention of cardiopulmonary dysfunction and fat embolism during cemented arthroplasty, we studied twenty-eight mongrel dogs that had had a bilateral cemented arthroplasty. Significant increases in pulmonary-artery pressure and pulmonary vascular resistance, accompanied by decreases in arterial oxygen tension and ...
Gladstone I M - - 1989
Antenatal corticosteroids reduce the incidence of the respiratory distress syndrome and improve pulmonary mechanics at least in part by mechanisms other than surfactant stimulation. We measured several aspects of pulmonary function in rabbits to better understand the mechanisms involved. Seven does were given intramuscular betamethasone and six were given vehicle ...
White P - - 1989
Three solutions, surfactant prepared from pig lungs, a mixture of synthetic phospholipids, and saline solution, were instilled into the middle ears of rats. The middle ear pressure necessary to force the eustachian tube open was studied. Ten minutes after instillation of pulmonary surfactant there was a 0.58 +/- 0.10 kPa ...
Sadovsky Y - - 1989
The purpose of this prospective and randomized study is to evaluate the safety and efficacy of prophylactic transcervical amnioinfusion in the management of labor complicated by meconium. A preexisting intrauterine pressure catheter was used for amnioinfusion. The incidence of thick meconium was significantly lower after amnioinfusion, compared with standard management ...
Engstrom P C - - 1989
Rabbits exposed to hyperoxia develop surfactant deficiency, abnormal lung mechanics, and increased permeability to solute. We investigated whether replenishment of depleted alveolar surfactant by the intratracheal instillation of calf lung surfactant extract (CLSE) would mitigate the increase in alveolar permeability to solute. Twenty-eight rabbits were exposed to 100% O2 for ...
Niblett D J - - 1989
Saline lavage of the lungs of eight anaesthetized New Zealand White rabbits was performed to produce a surfactant-depletion model of the neonatal respiratory distress syndrome. A characteristic change in the shape of the pressure-volume curve occurred, with the appearance of an inflection point on the inspiratory limb. The animals were ...
Hawkins E C - - 1989
Bronchoalveolar lavage fluid was collected from 12 anesthetized cats by use of an endotracheal tube and syringe adapter. The safety of the technique was evaluated by monitoring mucous membrane color, capillary refill time, pulse rate, respiratory rate, ECG, and arterial blood gas tensions and by necropsy findings. Group A consisted ...
Meredith K S - - 1989
To test the hypothesis that hyaline membrane disease (HMD) has a multifactorial etiology in which barotrauma plays a major role, we compared the immediate institution of high-frequency oscillatory ventilation (HFOV; 15 Hz, n = 5) with positive-pressure ventilation with positive end-expiratory pressure (PPV; n = 7) in premature baboons (140-days ...
Kobayashi T - - 1989
Immature newborn rabbits were treated at birth by tracheal instillation of porcine surfactant (100 microliters, phospholipid concentration 80 mg.ml-1), to which [14C]dipalmitoylphosphatidylcholine had been added as a marker. They were kept in a body plethysmograph/pneumotachygraph system at 37 degrees C. During a 120 min period of artificial ventilation with a ...
Robertson B - - 1989
Bronchopulmonary dysplasia (BPD) is a distortion of postnatal lung development induced by ventilator treatment for respiratory distress syndrome or other forms of respiratory failure in the newborn. This paper reviews established and proposed mechanisms involved in the pathogenesis of BPD including severe surfactant deficiency, ventilation with high insufflation pressure and ...
Tillman B F - - 1989
Radiation pneumonitis is a life-threatening result of therapeutic thoracic irradiation, yet its mechanisms are poorly understood. We studied the effects of unilateral lung irradiation (3,000 rad) in sheep from the immediate response to the later development of radiation pneumonitis. We defined radiation pneumonitis by its diagnostic clinical feature, radiographic infiltration ...
deLemos R A - - 1989
To assess the efficacy of high frequency oscillatory ventilation (HFOV) in the management of infants with hyaline membrane disease (HMD), we compared two HFOV strategies with conventional positive pressure ventilation with positive end expiratory pressure (PPV) for 24 h in premature baboons (140 d gestation). Three out of 14 PPV, ...
Schulze A - - 1989
The performance of a new infant ventilator system had to be evaluated. Technically it is characterized by flow (V)- and pressure (P)-transducers mounted immediately near the endotracheal tube. A microcomputer works as a function generator and governs servo-controllers for V and P thus offering a multiplicity of different modes both ...
Dorrington K L - - 1989
Apnoeic oxygenation (AO) combined with extracorporeal CO2 removal (ECCO2R), using venovenous perfusion across a membrane area of 0.1 m2 has been shown to be feasible in six healthy anaesthetized rabbits. In a further twelve rabbits, ECCO2R has been randomly compared with conventional mechanical ventilation (CMV) following saline lavage to induce ...
Lachmann B - - 1989
In the healthy and surfactant-depleted lungs of five pigs the influence of different forms of high frequency ventilation superimposed on conventional mechanical ventilation during the expiratory phase of the ventilatory cycle (SHFVE) on gas exchange and cardiocirculatory parameters was investigated. Subsequently the effects of end-expiratory flushing (EF), i.e. cleaning the ...
Rider E D - - 1989
We studied the effect on surfactant metabolism of 8 h of mechanical ventilation at tidal volumes of 13 +/- 0.3 ml/kg and very high tidal volumes of 28 +/- 1.5 ml/kg, with and without added CO2, in the presence of an atrial right to left shunt in 4- to 8-day-old ...
Goodwin S R - - 1988
Hydrocarbon aspiration is responsible for substantial morbidity and mortality in both children and domestic animals. To better understand the pathogenesis of hydrocarbon poisoning, we evaluated the effects of aspiration of 0.5 ml/kg of kerosene on various pulmonary and cardiovascular variables over a 4-hr period in a canine model. Heart rate ...
Ennema J J - - 1988
Adult guinea pigs were exposed to 100% oxygen until, after 54-85 h, they developed severe respiratory insufficiency. One subgroup of animals was ventilated artificially with 100% oxygen for an additional 60-960 min. When the PaO2 was less than 15 kPa or the PaCO2 greater than 20 kPa, 1 ml of ...
Wolfson M R - - 1988
In this report, an experimental approach and newly designed apparatus for liquid ventilation of preterm animals are described. Findings of age-related changes in cardiopulmonary function of this animal preparation are presented. Thirty-one lambs, 102-137 days gestation (term 147 +/- 3 days), were studied. The carotid artery, jugular vein, and trachea ...
Davis J M - - 1988
We assessed pulmonary mechanics in 35 premature infants with respiratory distress syndrome just before and one hour after the administration of 90 mg of surfactant to each infant. Transpulmonary pressure was measured between the airway opening and an esophageal balloon with use of a differential transducer, and flow rates were ...
Walsh M C - - 1988
Effective use of high-frequency oscillatory ventilation (HFOV) may require maintenance of adequate lung volume to optimize gas exchange. To determine the impact of inflation during HFOV, sustained inflation was applied at pressures of 5, 10, and 15 cmH2O above mean airway pressure for 3, 10, and 30 s to 15 ...
Berry D - - 1988
The effect of profound repetitive prenatal asphyxial insults on the cardiopulmonary function of premature ventilated lambs was studied. Twenty-nine fetal lambs (approximately 138 days gestational age) were exteriorized. In 16 of these lambs, the umbilical cord was occluded for 4 min then released for 10 min. This asphyxial episode was ...
Riley S - - 1988
The paper describes the use of two non-invasive techniques to provide simultaneous measurements of interface pressures and back shape in the seated posture. A modified wheelchair was used to provide adjustments of various seating parameters. The effects of varying seat angulation with four normal subjects are reported. The lumbar lordosis, ...
Evander E - - 1988
The influence of the detergent dioctyl sodium sulfosuccinate on clearance from the lungs of inhaled technetium-99m-labelled dietylenetriamine pentaacetate (99mTc-DTPA) was studied in twelve rabbits. An aerosol of dioctyl sodium sulfosuccinate or its vehicle alone was administered for 5 min prior to aerosolized 99mTc-DTPA via a bag-in-bottle system. Time-activity curves were ...
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