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Results 501 - 550 of 618
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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 ...
Jefferies A L - - 1988
Experiments were performed to determine the effects of conventional mechanical ventilation (CMV) and high-frequency oscillation (HFO) on the clearance of technetium-99m-labeled diethylenetriamine pentaacetate (99mTc-DTPA) from lungs with altered surface tension properties. A submicronic aerosol of 99mTc-DTPA was insufflated into the lungs of anesthetized, tracheotomized rabbits before and 1 h after ...
ElKady T - - 1988
Pregnant does were treated with betamethasone, T3, the combination of beta-methasone and T3 or vehicle control on days 24 and 25 of gestation. At 26 days gestational age, pressure-volume curves and lung rupture pressures and volumes were measured in the various groups of rabbits randomized to receive saline or surfactant ...
Wuthe J - - 1988
Respiratory distress syndrome (RDS) is characterized by quantitative and qualitative disturbances of surface active substances (surfactant). Therefore, intratracheal surfactant substitution is a favored subject of clinical investigations. In our study we tried to inflate and stabilize lungs in two steps: first, lungs were rinsed with a fluorocarbon and, second, artificially ...
Gerstmann D R - - 1988
To assess the influence of ventilatory technique on pulmonary baroinjury in experimental hyaline membrane disease, we randomized 24 premature baboons to six treatment groups according to ventilator (PPV, positive pressure ventilator; HFO, high frequency oscillator; HFI, high frequency flow interrupter) and O2 therapy FIO2 as clinically indicated, or FIO2 1.0). ...
Nieman G F - - 1988
The site of change in pulmonary vascular resistance (PVR) after surfactant displacement with the detergent diocytl sodium sulfosuccinate (OT) was studied in the isolated canine left lower lobe preparation. Changes in PVR were assessed using the arterial and venous occlusion technique and the vascular pressure-flow relationship. Changes in alveolar surface ...
Walther F J - - 1987
Twenty-six premature lambs were treated by tracheal instillation of [14C]labeled natural sheep surfactant before the onset of breathing or after the establishment of respiratory distress syndrome 30 min after birth. Half of both groups were subsequently ventilated for 3 h with 100% O2 by conventional mechanical ventilation (CMV) and half ...
Pérez Fontán J J - - 1987
We examined the respiratory effects of a patent ductus arteriosus in 29 premature lambs (131-135 days gestational age) after infiltrating the ductal wall with formaldehyde solution (Formalin) and placing a snare around the ductus to regulate its patency. The lambs were given sheep surfactant, paralyzed, and mechanically ventilated at birth. ...
Padbury J - - 1987
Plasma catecholamine levels increase dramatically at birth. To determine the contribution of adrenal catecholamine secretion to the surge in catecholamines at birth and the role in newborn adaptation, we performed surgical adrenalectomy or sham operation on near-term ovine fetuses. After recovery in utero, the animals were delivered and supported by ...
Clyman R I - - 1987
We created a model for studying the cardiovascular and pulmonary effects of patent ductus arteriosus (PDA) in premature lambs with respiratory distress. In 47 fetal lambs at 129 to 133 days gestation (term, 145 days), we infiltrated the ductus arteriosus with formalin and placed a mechanical occluder about it so ...
Ikegami M - - 1987
Pregnant does were treated with betamethasone, T3, TRH, or combinations of betamethasone plus T3 or TRH using doses of each agent known to effect lung maturation. Preterm rabbits were then delivered at 27 days gestational age, half of each group was treated with Surfactant TA, and the rabbits were ventilated ...
ElKady T - - 1987
We measured the effects of corticosteroids and surfactant individually and in combination on lung pressure-volume relationships, rupture pressures, and rupture volumes. Pregnant does were injected with betamethasone (0.1 mg/kg per day im) or vehicle on days 24 and 25 of gestation, and fetal rabbits were delivered on days 26 and ...
de los Santos R - - 1987
Healthy adult baboons exposed to 100% oxygen for 5 to 7 days maintained on continuous mechanical ventilation develop severe bilateral noncardiogenic pulmonary edema that resembles in many aspects the human adult respiratory distress syndrome (ARDS). In the present study, we evaluated the effects of hyperoxia for 5 to 6 days ...
Gonzalez-Rothi R J - - 1987
By consensus, the most clinically important consequence of near drowning is hypoxemia. Whether it is due to physiologic shunting induced by diffuse alveolar flooding from saltwater aspiration or to diffuse atelectasis induced by surfactant inactivation from freshwater aspiration, both physiologic disturbances can be reversed with the institution of positive-pressure breathing ...
Tooley W H - - 1987
We treated prematurely delivered rabbit pups with the synthetic surfactant that has been named Exosurf. By weight, Exosurf is 61.8% dipalmitoylphosphatidylcholine, 6.8% hexadecanol, 4.6% tyloxapol, and 26.7% NaCl. This simple mixture, suspended at 15 mg lipid X ml-1 water, has appropriate in vitro characteristics for a lung surfactant substitute. As ...
Warburton D - - 1987
To study the effects of beta-2 agonist on tracheal fluid, surfactant and pulmonary mechanics in fetal lamb lung, ritodrine hydrochloride, a preferential beta-2 agonist, was infused i.v. at a rate of 1.3 +/- 0.4 micrograms/kg/min (mean +/- S.D.) for 24 hr into six twin chronically catheterized fetal lambs starting between ...
Raj J U - - 1987
Increased alveolar surface tension due to surfactant deficiency is thought to result in a negative pressure surrounding pulmonary capillaries and to promote fluid filtration. To test this hypothesis, alveolar liquid pressure (Pliquid) was measured by micropuncture in isolated lungs of mature and immature fetal rabbits (with and without surfactant replacement) ...
Clark D A - - 1987
Meconium, an ether extract of meconium, and the major free fatty acids of meconium (palmitic, stearic, and oleic acids) were all found to increase the surface tension minimum of dog lung extract in a Wilhelmy balance. Each of these fractions was instilled into the lungs of dogs (15 experimental, eight ...
Lum H - - 1987
The independent roles of alveolar size and surface tension in relation to lung stability were investigated in 11 different mammalian species whose body weight ranged from 0.03 to 50 kg. This range in species provided a wide variation in subgross anatomy as well as a fourfold range in alveolar diameter. ...
Toorop G P - - 1987
We measured myocardial blood flow (QLVFW) and O2 consumption of the left ventricular free wall (VO2, LVFW) in 13 chronically instrumented, 7-wk-old lambs with an aortopulmonary left-to-right shunt (S) and in 10 control lambs without a shunt (C). The measured VO2, LVFW was compared with the calculated values obtained by ...
Evander E - - 1987
The influence of surfactant depletion on clearance from the lungs of inhaled technetium-99m-labeled diethylenetriamine pentaacetate (99mTc-DTPA) was studied in rabbits. Surfactant was removed by repeated lung lavage with isotone saline. To minimize structural damage to the lungs, pressure generated insufflation with short expiration was utilized. Aerosolized 99mTc-DTPA was administered via ...
Stagg R M - - 1987
The aims of this study were to investigate the effects of surfactants on the beta-adrenergic responses of the arterio-arterial (lamellar) vascular pathway of isolated gills from the trout Salmo gairdneri. The resistance of the arterio-arterial vasculature was monitored by measuring the input pressure of isolated gills perfused at a constant ...
Kofoed H - - 1986
The purpose of the study was to evaluate whether pathologic hypermobility of the lumbar spine could produce haemodynamic, metabolic, and histologic changes similar to those found in osteoarthritis. Five adult goats were surgically made hypermobile in the lumbar spine by an extensive laminectomy involving exarticulation of the facet joints of ...
Berggren P - - 1986
Severe respiratory insufficiency was induced in adult guinea pigs by repeated lung lavage. The animals were then ventilated for 75 min with 100% O2, insufflation pressure 28/6-8 cmH2O (2.7/0.6-0.8 kPa), frequency 30/min, and 33% inspiration time. One group of animals (I) was treated with protein-depleted porcine surfactant, prepared by a ...
Linderkamp O - - 1986
Whole cell and membrane deformability are essential for red blood cell (RBC) survival and for effective blood flow. Neonatal RBCs display several specific properties (eg, large size, high hemoglobin F) that could influence their deformation characteristics and contribute to their shortened life span. The present study was designed to compare ...
Lechner A J - - 1986
Prenatal starvation in the guinea pig causes reduced pulmonary diffusing capacity and retarded alveolarization among neonates. To study the impact of such starvation on biochemical and mechanical properties of the neonatal lung, pregnant guinea pigs were fed ad libitum throughout gestation or starved with 50% rations during their last trimester. ...
Brinckmann P - - 1986
Intradiscal injections of therapeutic doses of chymopapain were performed on specimens of the human lumbar spine. The changes in disc height, intradiscal pressure and endplate stress distribution, as well as in bending and flexion mobility, were observed during 8 hours after the injection. Injection of isotonic saline was used for ...
Oguchi K - - 1986
We compared the hemodynamic status and left ventricular (LV) performance in 7 twin pairs of preterm lambs delivered at 124 days gestational age (83% of term gestation) and ventilated by either conventional ventilation (CV) or high frequency ventilation (HFV) at 15 Hz. The lambs were treated with suspensions of natural ...
Walther F J - - 1986
The use of high oxygen concentrations and high mean airway pressures during mechanical ventilation of premature newborn infants with respiratory distress syndrome leads in 20%-30% of the survivors to chronic lung disease. This study explores if exogenous polyethylene glycol conjugated superoxide dismutase (PEG-SOD) and catalase (PEG-CAT) mitigate oxygen toxicity in ...
Jacobs H C - - 1985
Pulmonary surfactant (PS) is capable of lowering surface tension at an air-water interface to less than 10 dynes/cm. This property of PS is believed to be important for normal lung function. We tested the detergent Tween 20, which cannot lower surface tension at an air-water interface to less than 25 ...
Holm B A - - 1985
The time course of lung injury and recovery from a sublethal exposure to 100% O2 was investigated in adult rabbits. Animals were exposed to 100% O2 for 64 h and then returned to room air for varying periods of time up to 200 h. By the end of the exposure ...
Solimano A - - 1985
Twelve sets of twin lambs were delivered prematurely by cesarean section at 133-136 days gestational age and ventilated for 3 h with either high-frequency oscillation (HFO) or conventional mechanical ventilation (CMV). Blood gases and pH values were monitored at 30-min intervals, and ventilator settings were adjusted to maintain CO2 partial ...
Ekelund L - - 1985
At a gestational age of 27.9 days, pregnant rabbits were infused with enprofylline, a new xanthine with potent antiasthmatic effects. Following a priming dose of 5 mg/kg, 20 mg/kg were infused over a 2-h period. Controls received Ringer's solution. On completion of the infusion, the fetuses were delivered and the ...
Armengol J - - 1985
The role of prostaglandins (PG) in the pulmonary hypertension associated with high-frequency oscillatory ventilation (HFOV) was investigated in 7 pentobarbital-anesthetized dogs. The magnitude and time course of the mean pulmonary artery pressure (PAP) changes induced by HFOV (20 Hz) was quantified before and after PG-production blockade with 15 mg/kg indomethacin ...
Mirro R - - 1985
High-frequency oscillation (HFO) appears to be an alternate, less traumatic mode of ventilating surfactant-deficient patients, because conventional (mechanical) pressure-limited ventilation (CMV) compromises cardiac function at high mean airway pressures. We compared systemic cardiac output and its distribution during HFO and CMV in ten adult rabbits rendered surfactant deficient by repeated ...
Robertson B - - 1985
Immature newborn rabbits, delivered on day 27 of gestation, were ventilated artificially for 60 min, with or without previous treatment with natural surfactant. Insufflation pressure was adjusted to maintain an average tidal volume of about 10 ml/kg. All animals received, before the onset of ventilation, 125I-labeled albumin via the airways ...
Witten M L - - 1985
We measured lung clearance of aerosolized technetium-labeled diethylenetriamine pentaacetic acid (99mTcDTPA) as an index of alveolar epithelial permeability in rabbits exposed to cigarette smoke. Eighteen rabbits were randomly assigned to 3 equal-size groups: control, all smoke exposure (ASE), and limited smoke exposure (LSE). Cigarette or sham smoke was delivered by ...
Vidyasagar D - - 1985
As a prelude to clinical trials with a bovine surfactant (surfactant TA), in human infants with hyaline membrane disease, pulmonary and hemodynamic changes following its instillation in premature baboons were investigated. Baboons, delivered by cesarean section at 141 +/- 3.5 days (mean +/- SD, 77% gestation), were provided with intensive ...
Padbury J F - - 1985
A marked increase in sympathoadrenal activity at birth has been described in animals and humans. Studies to determine whether the magnitude and duration of the catecholamine surge at birth in preterm lambs is similar to full-term lambs were undertaken using an acutely exteriorized fetal lamb. To maintain a physiologically stable ...
Chen C T - - 1985
To evaluate the effect of meconium on pulmonary surface tension properties, the mechanics of 30 excised, separated canine pulmonary lobes were studied. Meconia were blended in normal saline to produce solutions of 10% and 20%. Solutions were filtered to remove large particles and instilled endobronchially into the canine lobes. The ...
Barkai G - - 1985
The effect of pressure on the lipid dynamics of the rat lung surfactant was studied in liposomes made of the natural lung surfactant of the rat and of model phospholipid mixture. The determined parameter was the lipid microviscosity, monitored by the fluorescence polarization of the probe 1,6-diphenyl-1,3,5-hexatriene. Osmotic pressure of ...
Seidenfeld J J - - 1985
Rabbits exposed to paraquat develop interstitial pneumonitis. A sublethal dose of paraquat (PQ) solution (250 mg/100 ml) was aerosolized by ultrasonic nebulization for one hour to rabbits in a closed vented chamber on two occasions with a five-day interval between exposures. Groups studied included saline-exposed (N = 4); saline-exposed, methylprednisolone ...
Berggren P - - 1985
A natural surfactant with low protein content (1%) was prepared by a sequence of cold centrifugation, heating to 90 degrees C, sucrose-gradient centrifugation, and extraction with chloroform:methanol. Some of the material was enriched with dipalmitoylphosphatidylcholine (DPPC) and unsaturated phosphatidylglycerol (PG) to relative concentrations of 56% and 10%, respectively. The in ...
Nieman G F - - 1985
The effect of the detergent dioctyl sodium sulfosuccinate on pulmonary extravascular water volume (PEWV) was studied in adult anesthetized mongrel dogs. The detergent was dissolved as a 1% solution in a vehicle of equal volumes of 95% ethanol and normal saline and administered by ultrasonic nebulizer attached to the inspiratory ...
Giovanelli B - - 1985
A pilot study using four subjects was conducted to investigate a proposed method of measuring 'in vivo' lumbar zygapophyseal intracapsular pressures. The authors were interested in establishing whether a resting pressure could be measured, and to observe pressure changes within the lumbar zygapophyseal capsules with fluid injection and with a ...
Robertson B - - 1984
Animal experiments and clinical trials have shown that the neonatal respiratory distress syndrome (RDS) can be treated effectively by surfactant replacement via the airways. This treatment facilitates the resorption of fetal pulmonary fluid, promotes uniform air expansion of the lungs, enhances gas exchange, reduces the protein leak across the alveolar ...
Kaplan G S - - 1984
The mechanical properties of the newborn piglet gallbladder were evaluated in both the stimulated and unstimulated states. The pressure-volume relationships, compliance, and the estimated active tension of the gallbladder were determined in 10 newborn piglets (2-7 days of age). Agonist stimulation was achieved by administration of histamine (25 micrograms/kg/h) and ...
Korda A R - - 1984
Saline or triiodothyronine (T3) (50-1000 micrograms) was injected into the amniotic sac of 17 pregnant ewes under general anesthesia at 130 days gestation. Forty-eight h later, the lambs were delivered by hysterotomy. Cord plasma T3 and cortisol and amniotic fluid T3 were assayed, and the maturity of the fetal lung ...
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