bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decreased phosphatidyl choline content in bronchoalveolar lavage fluids of children with bronchopulmonary dysplasia: A preliminary investigation
Authors: Clement A. , Masliah J. , Housset B. , Just J. , Garcia J. , Grimfeld A. , Tournier G. 
Published: March 2007

AbstractBronchoalveolar lavage (BAL) was performed on 12 infants who had recovered from neonatal acute respiratory failure and on 12 patients with bronchopulmonary dysplasia (BPD) in order to evaluate the concentration of phosphatidyl choline (PC) in BAL fluid These two groups were similar at birth (mean birth weight: 1,980 and 1,750 g, respectively; mean gestational age: 33.4 and 32.1 weeks respectively). Mechanical ventilation based on oxygen requirement lasted longer in the group with BPD. BAL was performed at the end of the first year of life (at 8.5 and 10.3 months, respectively) and the results were compared to control values (from infants of the same age without neonatal disease).Whereas the protein concentration in BAL fluid was similar in the two groups, a dramatic decrease of the BAL PC was found in BPD: The mean values of BAL‐PC over protein ratio were 0.9 in the group without pulmonary sequelae and 0.3 in the group with BPD These preliminary results suggest an impairment of the pulmonary surfactant metabolism in this chronic lung disease following neonatal acute respiratory failure. Pediatr Pulmonol 1987; 3:67–70.
Recurrent aspiration in children: Lipid‐laden alveolar macrophage quantitation
Authors: Colombo John L. , Hallberg Timothy K. 
Published: March 2007

AbstractWe prospectively evaluated bronchial washings from 45 patients aged 1 month to 25 years (mean 3.3 years) for the presence of lipid‐laden macrophages. By grading the amount of intracellular oil‐red‐O‐positive material, we determined a semiquantitative lipid‐laden macrophage index for each patient. All patients observed to be definite aspirators (n = 22) had indexes ≥86 (mean ± SD, 139 ± 46). All patients with no clinical suspicion of aspiration (n = 23) had indexes ⩽72 (mean ± SD, 21 ± 20). Our results suggest that simply sighting lipid‐laden macrophages is a nonspecific finding, but quantitation of these cells may be a very good test for recurrent aspiration of food substances in children. This test appears to be more sensitive than radiographic studies. Pediatr Pulmonol 1987; 3:89–89.
Effects of adenosine and xanthine derivatives on breathing during acute hypoxia in the anesthetized newborn piglet
Authors: Darnall Robert A. , Bruce R. Dean 
Published: March 2007

AbstractNeonates of animals and humans exhibit a parodoxical ventilatory response to hypoxia characterized by an initial increase in minute ventilation followed by a late, sustained decrease. Exogenous adenosine analogues cause respiratory depression, and the xanthine derivative aminophylline, a competitive inhibitor of adenosine receptors, decreases the amount of hypoxic ventilatory depression in the newborn piglet. Other xanthine derivatives such as enprofylline are weak adenosine antagonists. The purpose of this report is to test the hypothesis that enprofylline would not reverse ventilatory depression caused by hypoxia, supporting the suggestion that adenosine contributes to hypoxic ventilatory depression. To confirm the weak adenosine antagonism of enprofylline, L‐N6‐(phenylisopropyl)adenosine (PIA) was administered to six newborn piglets until respiratory depression was achieved. Either aminophylline or enprofylline was then administered. Aminophylline, but not enprofylline, reversed the respiratory depression caused by PIA. In seven additional piglets, respiratory depression was first produced by 10% oxygen breathing and the ability of saline, aminophylline, and enprofylline to reverse the decrease in ventilation was evaluated. The administration of either saline or enprofylline produced little change in minute ventilation (9.8% ± 3.7% and −11.7% ± 7.7%, respectively), whereas aminophylline consistently produced an increase (43.5% ± 7.3% [P < 0.001]). Both aminophylline and enprofylline increased heart rate (P < 0.01), whereas saline produced no significant change. Blood pressure was increased by enprofylline but not by aminophylline or saline. These findings suggest that, in the anesthetized newborn piglet, adenosine contriburtes to ventilatory depression caused by hypoxia. Pediatr Pulmonol 1987; 3:110–116.
Effect of oxygen on right ventricular performance evaluated by radionuclide angiography in two young patients with chronic lung disease
Authors: Alpert Brad E. , Gainey Margaret A. , Schidlow Daniel V. , Capitanio Marie A. 
Published: March 2007

AbstractPulmonary hypertension is a relatively common complication of chronic lung disease in children that can cause diminished right ventricular performace (RVP) and, eventually, cor pulmonale and heart failure. Since oxygen may decrease pulmonary artery pressure in these patients, we questioned whether RVP would also improve concmitantly. We evaluated the effect of oxygen on RVP in two young hypoxemic patients by radionuclide angiography. A child with bronchopulmonary dysplasia and cor pulmonale who was not clinically in heart failure had acutely better RVP while breathing oxygen and a further improvement after continuous oxygen therapy for 1 year. In a young adult with cystic fibrosis who was suspected of being in heart failure RVP acutely improved when the Flo2 was increased. We conclude that oxygen may improve RVP in hypoxemic patients and speculate that the observation of such improvement may be valuable for the early detection of patients who can benefit from long‐term oxygen therapy.
Trial of an intervention to reduce passive smoking in infancy
Authors: Woodward Alistair , Owen Neville , Grgurinovich Nick , Griffith Felicity , Linke Helen 
Published: March 2007

AbstractWe tested a health education intervention program to reduce passive smoking in infancy. The aim was to develop an instrument for study of tobacco smoke exposure and childhood respiratory illness. One hundred and eighty‐four women who had smoked during pregnancy were allocated by month of delivery to an intervention group, to a minimal contact group, or to a follow‐up only comparison group. Exposure to smoke was assessed 3 months later by questionnaire and by measurement of cotinine in samples of maternal and infant urine. There was a reduction in maternal smoking associated with contact with research staff, but this was not statistically significant. There were no differences between the groups in the exposure of infants to tobacco smoke. Reasons for this finding may include the timing of the intervention, the heterogeneity of the target group, and the manner in which information was presented on health risks caused by parental smoking.
Pulmonary mechanics in normal infants and young children during first 5 years of life
Authors: Gerhardt Tilo , Hehre Dorothy , Feller Rosalyn , Reifenberg Linda , Bancalari Eduardo 
Published: March 2007

AbstractTo characterize lung function in young children we measured lung compliance and pulmonary conductance in 40 normal infants and children ranging in age from the newborn period to 5 years. Inspiratory and expiratory flow was measured by a pneumotachograph, esophageal pressure through a water‐filled feeding tube, and functional residual capacity (FRC) by a N2 washout technique.The esophageal pressure change per breath [(mean ± SD) 7.3 ± 1.4 cm H2O] and specific compliance (75 ± 13 ml/cm H2O/L‐FRC) did not change with growth. Specific conductance was high (0.60 L/s/cm H2O/L‐FRC) in preterm infants, decreasing rapidly with initial growth but minimally beyond 10 kg of body weight, and stabilizing at 0.10 L/s/cm H2O/L‐FRC. During the age period studied, compliance increased approximately × 25 whereas conductance only rose five‐fold. The changes in compliance and conductance were well correlated to FRC, body weight, and length.These findings suggest that in the last trimester of pregnancy the airways are already well developed and postnatal lung growth occurs mainly by formation of new alveoli, leading to a proportional increase in FRC and lung compliance. Postnatally, conductance increases much more slowly than FRC, resulting in a rapid drop in specific conductance. Pediatr Pulmonol 1987; 3:309–316.
Rapid assessment of ventilation by measurement of carbon dioxide elimination during high‐frequency ventilation of kittens
Authors: Smith David W. , Frankel Lorry R. , Walker John G. , Cheng Eugene Y. , Meredith Keith S. , Mihm Frederick G. , Ariagno Ronald L. 
Published: March 2007

AbstractMonitoring of the effectiveness of ventilation is a significant problem during highfrequency ventilation (HFV). The time necessary to achieve equilibrium of the arterial tension of carbon dioxide (Paco2) following step changes in ventilation is appreciable, because of large body stores of CO2. Waiting for Paco2 to reach equilibrium is not only time‐consuming but a potentially dangerous means of monitoring ventilator adjustments during HFV. Five kittens of mean ± SD 1,082 ± 383 gm weight were studied during HFV, both with normal lungs and lungs injured by saline lavage‐induced surfactant depletion. The transcutaneous tension of carbon dioxide (Ptcco2) was monitored continuously to determine the time required to achieve equilibrium of Pacco2 following a step change in ventilation. The rate of pulmonary CO2 elimination (VECO2) was measured immediately before and immediately after ( < 12 sec) step changes in ventilation and was used to predict the change in Paco2 achieved once equilibrium was reestablished. With normal lungs, equilibration time following step changes in ventilation was found to be approximately 20 minutes. After step decreases in ventilation of the injured lung, achieving equilibrium state took significantly longer, approximately 30 minutes. The Paco2 predicted was significantly related to the change in Paco2 achieved at equilibrium for both normal and injured lung studies. We concluded that direct monitoring of Veco2 during HFV may be a useful clinical monitoring technique, allowing rapid and accurate assessment of the efficiency of ventilation following step changes in ventilation and potentially assisting in optimizing ventilator settings.
Lung growth in rats subsequent to administration of intraperitoneal elastase during the first 4 weeks of life
Authors: Thurlbeck William M. , Kida Kozui , Yasui Syuji , Utsuyama Masanori , Felix A. 
Published: March 2007

AbstractMale rats received intraperitoneal injections of porcine pancreatic elastase twice weekly during the first 4 weeks of life. Saline‐injected male rats served as controls. After a 4‐week recovery period, the rats were sacrificed, and the excised lungs were studied using saline‐ and air‐filled volume‐pressure curves, morphology, and biochemistry. Both air‐ and saline‐filled volume‐pressure curves showed loss of elastic recoil in the elastase‐treated animals. In elastase‐treated animals the mean linear intercept was increased, the numbers of alveoli per unit area, per unit volume, and per lung decreased, and alveolar surface area decreased. These animals also showed a disproportionate increase of alveolar duct air at the expense of the proportion of alveolar air. Morphometric differences between the elastasetreated animals and the controls were somewhat smaller in this experiment than in a previous one in which the animals were sacrificed immediately after 4 weeks of intraperitoneal elastase. We attribute this difference to alveolar multiplication between 4 and 8 weeks of age. However, evidence is presented that these alveoli were abnormal. Loss of recoil properties was more evident after the 4‐week recovery period than at the termination of elastase administration, suggesting that the newly formed alveoli were functionally abnormal. Collagen content was increased in the elastase group, but elastin was significantly decreased. This may be a good elastase model for assessing the hypothesis that lungs minimally damaged in infancy may have an increased susceptibility to environmental damage in later life.
Identifying lung overdistention during mechanical ventilation by using volume‐pressure loops
Authors: Fisher Joel B. , Mammel Mark C. , Coleman J. Michael , Bing Denis R. , Boros Stephen J. 
Published: March 2007

AbstractWe measured the pulmonary mechanics of 23 mechanically ventilated neonates. Airway pressures, inspiratory and expiratory flows were simultaneously measured. Values for respiratory system mechanics were then derived from these data by using a personal computer and a special software program. Volume‐pressure (V‐P) loops and respiratory system compliance values were determined for representative mechanical breaths. Twelve infants had normal‐appearing V‐P loops. Eleven had V‐P loops characteristic of lung overdistention, showing decreasing changes in volume with progressive increases in pressure. To quantify this visual observation, we determined the change in compliance during the last 20% of inspiration (C20). We then compared this value to the total compliance value for the entire breath (C) using the ratio C20/C. Mean values for C, C20, and C20/C were compared for the two patient groups. Total respiratory system compliance values were similar. C20 values were decreased in those patients with V‐P loops showing overdistention. C20/C values were significantly decreased in those patients with V‐P loop evidence of overdistention. Patients with V‐P loop evidence of overdistention all had C20/C values less than 0.8. Those with normalappearing V‐P loops all had C20/C values greater than 1.0. The C20/C ratio appears to effectively quantitate visual V‐P loop evidence of lung overdistention during mechanical ventilation.
Normal lung growth following antenatal dexamethasone treatment for respiratory distress syndrome
Authors: Wiebicke W. , Poynter A. , Chernick V. 
Published: March 2007

AbstractAntenatal steroid therapy reduces the incidence of respiratory distress syndrome (RDS) in premature infants. However, animal studies showed a decrease in lung cell number and lower lung weights in fetal rabbits exposed to hydrocortisone. This prompted us to measure flows and lung volumes (by spirometry and helium‐dilution method) in children > 6 years who were part of a study by the Collaborative Group on Antenatal Steroid Therapy. The effect of antenatal steroids on subsequent pulmonary function had not previously been studied. Of the 158 children originally enrolled before birth, a total of 8 dexamethasone (DEX)‐ and 11 placebo‐treated children were still local residents and fulfilled the criteria of the study (gestational age, 28–34 weeks; DEX/placebo treatment 1–7 days before delivery). Mean heights and weights were normal with no significant differences between the groups. Pulmonary function tests showed no differences in lung volumes or expiratory flows between the children whose mothers had received antenatal DEX and those who had received placebo. These results indicate no adverse effect of antenatal DEX on subsequent lung volumes and expiratory flows in childhood.
Oxygen toxicity in the infant rhesus monkey: Effects on regulatory peptides in lung and blood
Authors: Keith Ingegerd M. , Ekman Rolf , Farrell Philip M. 
Published: March 2007

AbstractA total of ten 6‐month‐old male rhesus monkey (Macaca mulatta) infants, born fullterm, were positive‐pressure ventilated with > 95% oxygen or room air (controls). A protocol was used which closely simulated pediatric intensive care. To test if regulatory peptides were affected by the oxygen treatment, and to search for an early marker of oxygen toxicity, lung tissue samples and systemic mixed venous blood were collected at 6, 12 and 24 hours after onset of treatment. The peptides, gastrin releasing peptide (GRP), calcitonin gene‐related peptide (CGRP), peptide YY (PYY), vasoactive intestinal peptide (VIP) and somatostatin (SOM), were quantitated in lung tissue extracts and plasma using radioimmunoassay.Lung tissue GRP, CGRP, and PYY levels appeared to decrease gradually with time, perhaps as a result of the positive pressure ventilation procedure. GRP and CGRP levels decreased less among monkey infants ventilated with oxygen, thus they were significantly higher at 24 hours than in air ventilated controls. VIP levels were significantly lower among tests compared to controls at that time. Blood peptide levels did not change with oxygen treatment.These results suggest that tissue concentrations of certain pulmonary regulatory peptides can become altered by ventilation with > 95% oxygen. A blood borne peptide marker was not identified.
Characterization of airway mucus from a fatal case of status asthmaticus
Authors: Bhaskar K. Ramakrishnan , De Feudis O'Sullivan Donna , Coles Stephen J. , Kozakewich Harry , Vawter Gordon P. , Reid Lynne M. 
Published: March 2007

AbstractWe used density gradient methods to analyze mucus recovered from the airways of a patient who died from status asthmaticus. At postmortem the mucus that plugged the length of the bronchial tree could only be removed by cutting with forceps. It was dispersed in cesium bromide (CsBr) and examined in the analytical ultracentrifuge. Surprisingly, no macromolecular component was seen in the buoyant density region typical of mucus glycoprotein (at 1.5 g/ml). The gelatinous material migrated to the region of lowest density, typical of lipids, and thin‐layer chromatography indicated that besides neutral lipids, a variety of phospho‐ and glycolipids (including gangliosides) were present. The residue left after the lipid extraction contained all sugar components of mucus glycoprotein, and alkaline borohydride cleaved oligosaccharides three to 12 sugars long, indicating that the sugars were O‐glycosidically linked as in mucus glycoproteins. Prior desulfation of the residue increased the number of oligosaccharides released by borohydride; analysis showed the presence in these of components (glucose, methylmannuronate) not present in epithelial glycoprotein. A trace component of high buoyant density was also present: Glucose was the predominant component in this, but glycoprotein sugars were also present. The above results suggest that in status asthmaticus plugging of the airways with mucus can occur even in the absence of typical epithelial glycoprotein and that lipids play a crucial role in such plugging.
Diminished radial count is found only postnatally in down's syndrome
Authors: Cooney Thomas P. , Wentworth Paul J. , Thurlbeck William M. 
Published: March 2007

AbstractAcinar complexity was assessed using the radial count in 23 patients with Down's syndrome. Late intrauterine growth of the lung is not impaired, and acinar complexity is normal. Thereafter, decreased acinar complexity occurs and is grossly and microscopically apparent by 4 months of age. The gross appearance is characteristic, consisting of a diffuse and uniform porosity of the cut surface of the lung. Microscopically, this appearance is due to the presence of dilated alveoli and alveolar ducts. Children and adults with Down's syndrome have a significantly reduced number of alveoli, which are enlarged. In the majority of cases, the alveoli have a double capillary network that has not been described in any other lung condition. No correlation could be established between the radial count and the presence or absence of double capillary network, hypertensive pulmonary vascular disease, or congenital heart disease. The unique appearance of the lung in Down's syndrome results from failure of the lung to develop properly in the postnatal period, presumably genetically determined.
Management of an unusual case of congenital lobar emphysema
Authors: Hill Ronald C. , Mantese Vito , Spock Alexander , Wolfe Walter G. 
Published: March 2007

AbstractA 10‐week‐old infant, who presented with respiratory embarrassment, was found to have an azygos lobe complicated by congenital lobar emphysema. The pediatric work‐up, operative management, and postoperative course are described. The cases presenting at Duke University Medical Center are reviewed.
Lung perfusion and aerosol distributions in preterm ventilated lambs
Authors: Berry David , Ikegami Machiko , Jobe Alan 
Published: March 2007

AbstractThe relative distributions of ventilation as measured by 99Tc‐sulfur colloid aerosol deposition and pulmonary perfusion (measured with radiolabeled microspheres) were determined in 12 preterm lambs that were delivered at 138 days gestational age and ventilated for 4 hrs. To verify that unventilated lung segments in these lambs would have decreased perfusion, a balloon catheter was placed in a major bronchus either at birth or after 2 hrs of ventilation. This catheter prevented ventilation of 24.5 ± 3.2% of the lung tissue. After 4 hrs of ventilation, the lambs were sacrificed and the lungs were divided into about 60 1‐g pieces. Apart from the occluded, atelectatic segments, the lungs were visually well aerated with only 5.3 ± 1.8% of the nonobstructed lungs being spontaneously atelectatic. There was a 66.5 ± 0.07% decrease in blood flow to the area of lung made atelectatic by the balloon. The blood flow also was decreased to lung regions assessed to be spontaneously atelectatic. No 99TC‐sulfur colloid recovered from balloon‐occluded lung regions, and less 99Tc‐sulfur colloid was found in the spontaneously atelectatic areas than in aerated lung regions. There were significant correlations (P <0.001) between pulmonary blood flow and aerosol recovery in each of the 12 animals. Premature lambs had a wide variability in ventilation and perfusion, but the relative ventilation to perfusion ratio was regulated to minimize the intrapulmonary shunt.
Decreased incidence of subglottic stenosis using an “appropriate‐sized” endotracheal tube in neonates
Authors: Sherman James M. , Nelson Hillary 
Published: March 2007

AbstractIn a previous study of factors influencing the development of acquired subglottic stenosis (SS) we proposed choosing an endotracheal tube (ETT) size such that the ratio of the external diameter divided by the gestational age of the infant in weeks was less than 0.1. We have prospectively followed 44 patients intubated longer than 25 days. One of 36 patients intubated according to the above protocol developed significant SS compared to 3 of 8 patients intubated with an ETT larger than suggested. In a previous study, 9 of 49 patients intubated longer than 25 days developed SS. The incidence of SS in patients intubated with “appropriatesized” ETT was less than either other group of patients (P <0.005 and P <0.05, respectively). This study confirms the suggestion that choosing ETT size by the above protocol will lessen, although by itself not eliminate, the incidence of acquired SS.
Monitoring theophylline levels in serum and saliva using fluorescence polarization immunoassay and seralyzer
Authors: Schulte Theodor , Buhr Wernfried , Schmidt Marco , Walkenbach Andreas , Berdel Dietrich 
Published: March 2007

AbstractThe reliability and predictive value of salivary theophylline levels was investigated in 58 children who were treated with oral sustained‐release theophylline preparations for bronchial asthma. Serum and saliva levels were assessed by fluorescence polarization immunoassay (FPIA), and Seralyzer (reagent strip reflectance photometer method). Forty‐six paired serum and saliva samples from 26 patients (Group 1) were used to develop a linear regression formula. This formula was tested on 130 paired serum and saliva samples from 32 patients (Group 2). When saliva theophylline levels were assayed using FPIA, 95% of serum levels were predicted within 30% of the measured value. Using Seralyzer, 95% of serum levels were predicted within 45% of the measured value. For patients with three and more paired serum and saliva specimens, individual regression formulas were determined showing considerable variation. This study indicates that salivary theophylline levels provide for an estimation of serum levels if FPIA is used. The Seralyzer technique is only useful for serum theophylline measurements. Using a special device it is now easier to obtain saliva samples than by conventional methods.