bluuebunny/crossref_metadata_2025 huggingface dataset:
Does nifedipine affect the diurnal variation of asthma in children?
Authors: Sly Peter D. , Olinsky Anthony , Landau Louis I.
Published: March 2007

Diurnal variations in airway caliber and in bronchial reactivity have been described. The mechanisms underlyins these variations are not known. The hypothesis that these variations can be diminished by calcium channel blockers was tested by giving 22 asthmatic children 10 mg of nifedipine or identical placebo three times a day for 4 weeks in a double‐blind, randomized, crossover‐designed study. Treatment with nifedipine did not diminish the diurnal variations in airway caliber, judged from peak expiratory flow rates, or in bronchial reactivity, judged from bronchodilator responsiveness. Group mean amplitude of the diurnal variation in airway caliber was 10.5% on nifedipine and 10.6% on placebo. Group mean amplitude of the diurnal variation in bronchodilator responsiveness was 75.4% on nifedipine and 69.5% on placebo. There were no differences in mean peak expiratory flow rate between nifedipine and placebo periods. This study did not find any evidence to support the hypothesis that the diurnal variations in airway caliber and in bronchial reactivity can be diminished by calcium channel blockers.
Aminophylline reduces hypoxic ventilatory depression without increasing catecholamines
Authors: Bruce R. Dean , Darnall Robert A. , Althaus John S.
Published: March 2007

Aminophylline reduces hypoxic ventilatory depression in newborn piglets and can enhance the release of catecholamines (CATs), which in turn may stimulate ventilation. To determine if the effect of aminophylline on ventilation was due to the release of CATs, we measured plasma CATs and ventilation in two groups of spontaneously breathing newborn piglets less than 4 days old, treated with either aminophylline (n = 7) or normal saline solution (n = 6) during both normoxia and hypoxia. The piglets were anesthetized with ketamine and xylazine and intubated, and the femoral artery was catheterized. Epinephrine and norepinephrine were measured before and 30 minutes after treatment with aminophylline (15 mg/kg) or normal saline. The animals were exposed to 10% oxygen and the CATs again measured after 5 minutes of hypoxia. Respiratory rate, expiratory flow integrated to minute ventilation (VE), heart rate, and blood pressure were continuously recorded. CATs were assayed by high‐pressure liquid chromatography with electrochemical detection. Treatment with aminophylline during normoxia was associated with an increase in tidal volume. During hypoxia, treatment with aminophylline prevented a fall in VF and respiratory rate seen in the normal saline group. Epinephrine and norepinephrine increased during hypoxia, but there was no difference between the groups at 5 minutes. In our model the increase in CATs observed during hypoxia was not enhanced by aminophylline. This is consistent with the hypothesis that some mechanism other than catecholamine release is responsible for the effect of aminophylline in reducing neonatal hypoxic respiratory depression.
Congenital tracheal stenosis with associated cardiopulmonary anomalies: Report of two cases with a review of the literature
Authors: Voland Joseph R. , Benirschke Kurt , Saunders Brian
Published: March 2007

We present two infants with congenital tracheal stenosis with complete tracheal rings. Both had associated congenital anomalies. The first case showed cardiac malformations, and the second case had agenesis of the right lung. We review the literature, in particular with reference to tracheal stenosis and pulmonary agenesis. We also propose that the constellation of anomalies may result from defects in the cervical mesenchyme and, as such, may represent one end of a spectrum of cervical mesenchymal field defects.
Modification of nonspecific bronchial reactivity in hypothyroid children under different regimens of substitutive opotherapy
Authors: Villa M. P. , Bernardi F. , Macri F. , Alonge C. , Cacciari E. , Cerimoniale G. , Criscione S. , Ronchetti R.
Published: March 2007

Although it has been experimentally proved that thyroid hormones stimulate beta2 receptor activity and tissue responsiveness to catecholamines, previous studies have established that asthma and nonspecific bronchial reactivity (NSBR) can worsen if complicated by hyperthyroidism. Our study is an effort toward the analysis of this contradiction. In 20 congenitally hypothyroid children, substitutive opotherapy was completely withdrawn for 1 month, resumed in the original dosage for 2 months, and then increased by 20% from day 91 to day 110. Mean NSBR, expressed in carbachol‐related PD20‐FEV1 and PD25‐V25, was significantly increased by day 30, remained significantly elevated by day 90, and returned to initial values by day 110. These results suggest that thyroid hormones per se in nonasthmatic subjects decrease bronchial reactivity. This observation should be taken into consideration when attempting to explain the worsening condition of asthmatics who become affected with hypothyroidism. Bronchial reactivity appears to be under the control of many factors (including thyroid hormone levels). Once it is altered, a period of time seems necessary to restore the original bronchomotor tone (2 months in our study).
Forced expirations against a variable resistance: A new chest physiotherapy method in cystic fibrosis
Authors: Oberwaldner Beatrice , Evans Johannes C. , Zach Maximilian S.
Published: March 2007

Twenty patients with cystic fibrosis (CF) were trained to mobilize intrabronchial secretions by a new method of positive expiratory pressure mask (PEP mask) physiotherapy (PT). Patients repeatedly expired forcefully through the PEP mask; expiratory resistance was varied by eight different internal diameter resistors at the outlet. Forced vital capacity with the mask (FVCPEP) was determined for each resistor and was compared with the one measured without the instrument (FVC); simultaneously the sustained expiratory pressure (SEP) developed against the resistance was recorded. After training, each patient exceeded FVC with one or more resistors; “optimum” FVCPEP was 124 ± 16% FVC at a SEP of 61 ± 21 cm H2O. Using the PEP mask, patients cleared a higher percentage of their daily sputum volume than with conventional PT (78 ± 22% versus 53 ± 17%, p < 0.01). In 11 patients (subgroup 1), multiple aspects of lung function were measured at the beginning of the study, after 10 months with PEP mask PT, after two further months without using the mask but with conventional PT, and after six more months with PEP mask PT. Results showed significantly increased expiratory flow rates, significantly decreased hyperinflation and airway instability with PEP mask PT, and a marked decline of lung function without it. The remaining nine patients (subgroup 2) entered into the same protocol; based on findings in subgroup 1 and on ethical considerations, however, the control period without PEP mask PT was then omitted, resulting in a steady and statistically significant improvement of lung function over the entire observation period. In the course of preliminary trials, two children transiently used a suboptimal resistance (FVCPEP < FVC) and responded with a deterioration of lung function. By dilating airways and evacuating trapped gas, this method of PEP mask PT improves lung function and mucus clearance in CF. Thorough practice with the technique and frequent control of the optimal resistance are mandatory.
Differences in drug susceptibility between isolates of pseudomonas cepacia recovered from patients with cystic fibrosis and other sources and its relationship to beta‐lactamase focusing pattern
Authors: Aronoff Stephen C. , Labrozzi Pauline H.
Published: March 2007

Pseudomonas cepacia, a significant pulmonary pathogen among children with cystic fibrosis (CF), often possesses an inducible β‐lactamase. The β‐lactamase isoelectric focusing pattern and β‐lactam susceptibility of CF and non‐CF isolates of P. cepacia were compared. Against all of the test strains, ceftazidime and piperacillin were more effective than aztreonam. More CF isolates were resistant to 8 μg/ml of ceftazidime than non‐CF isolates. Isoelectric focusing of cefoxitin‐induced, cell‐free preparations of the CF isolates produced significantly more bands than comparable preparations of non‐CF isolates. Organisms producing a β‐lactamase band that focused in the pH range of 8.5 to 8.7 were significantly more resistant to 8 μg/ml of ceftazidime than other isolates. The increased resistance of CF isolates of P. cepacia to ceftazidime may be the result of the production of a specific bacterial β‐lactamase.
Exhalation time effects on arterial and venous blood oxygen content and arterial P during high frequency jet ventilation of surfactant‐depleted cats
Authors: Johnston Jerrilyn , Carlstrom Jeffrey R. , Gonzalez Felipe , Richardson Peter
Published: March 2007

Since high frequency jet ventilation (HFJV) relies on lung mechanics for the passive removal of expiratory gas, one would predict that the time allowed for exhalation would have serious effects on cardiopulmonary function. To document these effects we lavaged the lungs of ten cats with 30 ml/kg of saline six times, then sampled arterial and venous blood while the animals were ventilated conventionally at 30 BPM and then with HFJV at 600 BPM, varying inspiratory/expiratory ratios (I/E) from 1:1 to 1:5. The animals breathed 100% O2 throughout the study, and the mean airway pressure was held constant for each animal when the I/E was varied during HFJV. Decreasing the I/E from 1:1 to 1:5 during HFJV resulted in an increase of arterial oxygen content (Ca) from 11.3 ± 1.2S E to 13.6 ± 1.2 ml O2/100 ml blood (P < 0.01), a decrease of Pa from 43 ± 6 to 27 ± 4 mm Hg, and an increase of alveolar to arterial oxygen gradient from 351 ± 49 to 377 ± 49 mm Hg. The ratio of systemic blood flow to oxygen consumption (Q̇/V̇) was similar during conventional ventilation and with HFJV at I/E of 1:1 (18.9 ± 3.7 vs 18.0 ± 2.9) but decreased when I/E was reduced to 1:5 during HFJV (13.9 ± 2.1). The ratio of the product of Ca and Q̇ (systemic oxygen availability) to V̇ (ST/V̇) remained unchanged during all modes of ventilation (1.75 ± 0.15). The increase in Ca observed when I/E was reduced from 1:1 to 1:5 during HFJV was counterbalanced by a decrease in Q̇/V̇ such that ST/V̇ remained relatively constant. Pediatr Pulmonol 1987; 3:19–23.
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

Bronchoalveolar 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

We 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

Neonates 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

Pulmonary 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

We 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

To 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

Monitoring 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

Male 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

We 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

Antenatal 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

A 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

We 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

Acinar 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

A 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

The 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

In 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

The 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.
Inspiratory‐to‐expiratory ratio during ventilation for idiopathic respiratory distress syndrome
Authors: Field D. , Milner A. D. , Hopkin I. E.
Published: March 2007

We have studied the effects of changes in inspiratory‐to‐expiratory ratios (I/E ratios) on transcutaneous blood gases in a group of 30 infants receiving respiratory support for the idiopathic respiratory distress syndrome(IRDS). Following the use of a reversed I/E ratio (inspiration exceeding expiration), changes in oxygenation were very variable but improvements were seen most consistently in babies weighing > 1,750 g and <850 g. The use of reversed I/E ratios seemed less efficient than positive end‐expiratory pressure in raising TcP for the same increase in mean airway pressure. Changes from a 1:1 ratio to a normal I/E ratio, in which expiratory time exceeded inspiratory time by 50–100%, led to more marked and consistent falls in TcP. We conclude that a flexible attitude toward the use of I/E ratios should be adopted to avoid raising mean airway pressure needlessly. Pediatr Pulmonol. 1989; 7:2–7.
Granulocyte elastase‐mediated proteolysis of alpha1‐antitrypsin in cystic fibrosis bronchopulmonary secretions
Authors: Cantin André , Bilodeau Ginette , Bégin Raymond
Published: March 2007

Airway secretions of patients with cystic fibrosis (CF) contain large amounts of alpha1‐antitrypsin (α1‐AT), yet elastase activity is also often detectable, suggesting that airway α1‐AT may not be functional in some CF patients. It is unknown whether in CF sputum α1‐AT is inactivated by oxidants, neutrophil metalloproteinases, bacterial elastase, or neutrophil elastase. To investigate the mechanism(s) by which α1‐AT may be inactivated in CF airway secretions, sputum samples were obtained from nine patients during respiratory physiotherapy. α1‐AT was measured by radial immunodiffusion. Sputum‐α1‐AT was purified by antibody affinity chromatography. Electrophoresis of α1‐AT from seven patients with acute infectious exacerbations revealed two distinct components: a minor band corresponding to an elastase/α1‐AT complex and a major band typical of proteolysed α1‐AT (Mr = 48 kD). Each patient had large amounts of sputum elastase activity. In contrast, two patients without free sputum elastase activity had intact sputum α1‐AT; however, α1‐AT was partially truncated by porcine pancreatic elastase suggesting that the α1‐AT may have been partially oxidized. Adding α1‐AT purified from normal serum to α1‐AT‐depleted sputum containing elastase activity resulted in a small α1‐AT/elastase complex with most α1‐AT being truncated. The serine proteinase inhibitor phenylmethylsulfonyl fluoride but not the metalloproteinase inhibitor EDTA prevented α1‐AT proteolysis, thus granulocyte elastase can mediate α1‐AT‐AT degradation in CF. Apparently, the large granulocyte elastase burden in some acutely ill patients with cystic fibrosis can proteolytically inactivate α1‐AT. Pediatr Pilmonol. 1989; 7:12–17.
Comparison of a new multidose powder inhaler with a pressurized aerosol in children with asthma
Authors: Fuglsang Gunver , Pedersen Søren
Published: March 2007

Thirteen children with asthma were treated with cumulative doses of terbutaline delivered as a pressurized aerosol and from a new multidose powder inhaler (Turbuhaler) in a randomized cross‐over dose‐response study. The cumulative dose of terbutaline was 2 mg on each study day. All children used a correct aerosol inhalation technique. At no time was there any difference in forced expiratory volume in 1 s (FEV1), forced midexpiratory flow, forced vital capacity, peak expiratory flow rate, or percent increase in these parameters between the two inhalers. The mean total increases in FEV1 after 2 mg terbutaline were 60% (aerosol) and 62% (Turbuhaler); 90% of these increases were measured after a cumulative dose of 0.5 mg terbutaline. One milligram of terbutaline inhaled from a Nebuhaler at the end of each study day did not result in additional increase of pulmonary functions, indicating that maximal bronchodilation had been achieved with both inhalers. After a cumulative dose of 2 mg terbutaline from the aerosol seven children complained of tremor and one of restlessness. No side effects were reported when the Turbuhaler was used (P < 0.02). Pediatr Pilmonol. 1989; 7:112–115.
Variation in peak expiratory flow of normal and asymptomatic asthmatic children
Authors: Albertini M. , Politano S. , Berard E. , Boutte P. , Mariani R.
Published: March 2007

Peak expiratory flow (PEF) variation was measured in 18 healthy children (Group I) aged 9.25 to 13.3 years (mean, 11 years) and in 17 asymptomatic asthmatic children (Group II) aged 8.75 to 14.25 years (mean, 11.9 years) receiving no bronchodilators. PEF was measured four times a day for a period of 10–14 days. There were no differences between Group I and Group II regarding age, height, weight, sex, duration of the study, and overall mean PEF values. Mean daily PEF variation amplitude (difference between the highest and the lowest daily values as a percent of the mean) was significantly higher in Group II than in Group I subjects (15.2 vs. 9.9%), and so was cosinor amplitude (9.6 vs. 5.9%). Significant circadian rhythm in PEF was detected by cosinor analysis in nine subjects of Group I and in eight subjects of Group II. Mean PEF bathyphase calculated by cosinor analysis (trough time in a 24 h scale) was similar in the two groups (0503 h, in Group I and 0434 h in Group II). The results of this study show that the amplitude of circadian variation in PEF tends to be higher in asymptomatic asthmatic children than in normal children, but there is too much overlap to use PEF monitoring to identify an individual asymptomatic asthmatic child. Therefore, diurnal variation of PEF is not suitable for diagnosing mild asthmatics. Pediatr Pilmonol. 1989; 7:140–144.
Connective tissue, mechanical, and morphometric changes in the lungs of weanling rats fed a low protein diet
Authors: Matsui Reiko , Thurlbeck William M. , Fujita Yoshiaki , Yu Shiu Yeh , Kida Kozui
Published: March 2007

We studied the effect of low‐protein diet (8% casein) on lung growth in rats from 3 to 7 weeks of age. Their diet was isocaloric with that of control animals fed a diet of 20% casein. The calorie intake of experimental animals was increased during the first 3 weeks of the experiment, but they increased less (about 10%) in body weight, had less protein and less water when the whole body was examined, and had lower serum proteins and decreased urinary hydroxyproline. The experimental animals remained in positive nitrogen balance by maintaining low urinary nitrogen excretion. The lungs of the experimental animals were abnormal, with decreased absolute amounts of hydroxyproline and desmosine and of these relative to unit lung weight. The lungs contained more air per gram of lung tissue, and the volume of air in the lung was increased at all transpulmonary pressures above zero. When corrected for increased total lung capacity, there was a loss of recoil at mid‐lung volumes. Saline‐filled volume‐pressure curves, corrected for lung volume, showed similar loss of recoil. Alveolar multiplication was quantitatively normal, but the experimental animals had larger alveoli. We conclude that the protein deprivation in isocalorically fed animals has a specific effect on lung scleroprotein content, which may be due to diminished synthesis, and this results in both structural and functional abnormalities in the lung. Our results indicate the importance of dietary protein in lung development and possibly as one of the causes of emphysema. Further studies are needed to know whether this would be a problem in infants of Kwashiokor. Pediatr Pilmonol. 1989; 7:159‐166.
Ventilatory response to combined high frequency jet ventilation and conventional mechanical ventilation for the rescue treatment of severe neonatal lung disease
Authors: Spitzer Alan R. , Butler Sharon , Fox William W.
Published: March 2007

High frequency jet ventilation (HFJV) was used to treat 176 infants who were either failing to respond to conventional mechanical ventilation (CMV) or demonstrating pulmonary air leak. The median birthweight for infants treated with HFJV was 1530 g, median gestational age was 31 weeks. Median duration of therapy with HFJV was 3.0, with a range of 0.1 to 27 days. During the first 24 hours of treatment, mean airway pressure decreased from 16.2 ± 0.3 (Mean ± SEM) cmH2O to 12.2 ± 0.3 cmH2O, while mean Pa increased from 65.3 ± 3.0 torr to 93.3 ± 3.0 torr during the same time period. Simultaneously, mean Pa decreased from 46.4 ± 1.5 torr to 36.6 ± 1.0 torr, although peak inflating pressure decreased from 34.3 ± 0.7 cmH2O to 30.1 ± 0.8 cmH2O. Ninety‐five (54%) infants treated with HFJV survived. Of 123 infants with RDS 75 (61%) survived. The rate of complications for HFJV patients was similar to that seen with CMV in our nursery. This study suggests that HFJV provides improved oxygenation and ventilation of infants at lower mean and peak pressures compared to conventional mechanical ventilation. HFJV combined with CMV may be a valuable adjunct to therapy in infants with severe lung disease. Pediatr Pulmonol 1989; 7:244–250.
Tracking of lung function in healthy children and adolescents
Authors: Hibbert Marienne E. , Hudson Irene L. , Lanigan Anna , Landau Louis I. , Phelan Peter D.
Published: March 2007

Two hundred twenty‐six healthy school children, with a mean age of 8.8 years; 62 girls mean age 8.8, 48 boys mean age 12.6 and 51 girls mean age 12.6 years at the start, were enrolled in a longitudinal study of lung function and tested annually for 5 years. All were free of respiratory symptoms, and none smoked more than five cigarettes per week during the 5 years. Static and dynamic lung volumes (other than residual volume), maximum expiratory and inspiratory flows, and maximum mouth pressures “track,” that is, individuals remain at a constant deviation from the sample mean over time. The data indicate that these measurements of lung function in healthy individuals grow in constant proportion relative to other healthy children and adolescents. Pediatr Pulmonol 1990; 8:172‐177.
Effect of inhaled disodium cromoglycate and albuterol on energy cost of running in asthmatic children
Authors: Zanconato Stefania , Baraldi Eugenio , Santuz Pierantonio , Magagnin Giampiero , Zacchello Franco
Published: March 2007

The purpose of this study is to evaluate the effect of disodium cromoglycate and albuterol on energy cost of running, gas exchange, and ventilation during maximal exercise in children with exercise‐induced asthma (EIA). Twelve children (7.1–15.5 years old) with a history of mild to moderate asthma and EIA performed three maximal exercise tests on a treadmill: 1) test A, without premedication; 2) test B, after premedication with inhaled disodium cromoglycate (DSCG) (40 mg); 3) test C, after premedication with inhaled albuterol (200 μg). The energy cost of running was calculated at each minute of exercise. None of the children were limited by dyspnea during the run. The post‐exercise fall in FEVi after test A was greater than 20% for each child, the mean fall being 32.8 ± 11.6%, in comparison with 12.6 ± 8.9% after test B (P < 0.001) and 2.5 ± 5.3% after test C (P < 0.001). There was no difference in the baseline oxygen uptake for the three tests. Maximum oxygen uptake (V̇ peak) decreased from 43.9 ± 7.7 mL/min/kg in test A to 37.7 ± 6.0 mL/min/kg in test B (P < 0.01) and 39.1 ± 7.2 mL/min/kg in test C (P < 0.05). Ventilatory anaerobic threshold in tests B and C was significantly lower than in test A (P < 0.01). Ventilation (L/min) and energy cost of running (O2 mL/kg/m) were significantly lower in tests B and C than in test A at comparable times. Running time was longer in B and C (P < 0.05) with respect to A. In conclusion, premedication with DSCG and albuterol causes a decrease in ventilation and energy cost of running during exercise in children with EIA. Pediatr Pulmonol 1990; 8:240‐244.
Single breath versus panting technique in salbutamol delivery through a 750 mL spacing device
Authors: James R. W. , Masters I. B.
Published: March 2007

Spacing devices have been widely advocated for asthmatic patients having difficulty actuating metered aerosols and co‐ordinating inspiration. Studies have generally supported the slow inspiration/breath hold technique. This requires conscious respiratory control. Such control is often not possible in young children; consequently panting techniques are widely recommended. The panting technique has not been studied.

The aim of this study was to compare the bronchodilator effectiveness of panting and the single breath maneuver, each followed by a breath hold, and each at functional residual capacity (FRC), using a Volumatic Spacer®.

The study design was a randomly allocated cross‐over assessment of bronchodilator response for each technique. The drug dosage was controlled by limiting the inspired volumes of gas (single and cummulative) to the pretested inspiratory capacity. Two hundred micrograms of salbutamol was delivered into the spacer.

Twenty‐one patients were entered in the study and 15 (mean age ± SD = 10.9 ± 3.3 years) completed the protocol. There was no significant difference in bronchodilator response between the two groups. We conclude that the panting and the single breath techniques are equally effective in children of this age group. Pediatr Pulmonol 1990; 8:263‐267.