bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postnatal growth of genioglossal motoneurons
Authors: Brozanski Beverly S. , Guthrie Robert D. , Volk Etta A. , Cameron William E. 
Published: March 2007

AbstractThe postnatal growth of kitten genioglossal motoneurons was examined in six different age groups (newborn, 2, 4, 8, and 12 weeks and adult) using the technique of retrograde transport of horseradish peroxidase (HRP). The cell bodies of 100–150 motoneurons in each age group were analyzed in a transverse plane of section using standard techniques.Somatic genioglossal motoneuron growth occurred primarily along the major axis, which increased from 25.2 μm to 41.3 μm between birth and 8 weeks of postnatal age, after which time there was no further increase in either major or minor dimension of the cell body. The form factor decreased from 0.94 to 0.80 from birth to adulthood indicating an increased eccentricity of the cell body. The number of primary dendrites visible with this technique remained constant throughout the postnatal period.Calculated somal surface area increased in a linear fashion from birth through 8 weeks of postnatal life. There was no further increase in surface area beyond this age. The rate of increase in somal surface area with age was significantly different from both the rate of increase of animal weight and animal surface area with age.The correlations between the demonstrated immature genioglossal morphology and its cellular electrophysiology or integrated respiratory function remain unknown. The recent demonstration of decreased activation of the genioglossus muscle following airway occlusion in premature infants with apnea suggests that the relationships between developing genioglossal motoneuron structure and function warrant further investigation. Pediatr Pilmonol. 1989; 7:133‐139.
Childhood asthma following hospitalization with acute viral bronchiolitis in infancy
Authors: Sly Peter D. , Hibbert Marienne E. 
Published: March 2007

AbstractA prospective follow‐up of 48 infants hospitalized with respiratory syncytial virus bronchiolitis in the first year of life revealed that 44 of these infants had symptoms suggestive of asthma in the 5 years following their initial illness (cumulative prevalence 92%). Symptoms became less frequent and less troublesome during the follow‐up period. Thirty‐five of these children visited the laboratory for clinical examination, pulmonary function testing, and histamine challenge. Twenty‐five children were believed to have clinical evidence of asthma at the time of the laboratory visit (point prevalence 71%). Five children were unable to perform pulmonary function tests; 25 of the remaining 30 (67%) had a positive histamine challenge test. No relationship could be demonstrated between a clinical diagnosis of asthma, a family history of atopy, and the results of histamine challenge testing. These results question the relationship between the results of bronchial provocation tests and clinical asthma in this age group. Pediatr Pilmonol. 1989; 7:153–158.
In vitro performance of the small particle aerosol generator (SPAG‐2)
Authors: Newth C. J. L. , Clark A. R. 
Published: March 2007

AbstractThe anti‐viral drug ribavirin primarily used for the treatment of respiratory syncytial virus (RSV) infection in infants is delivered by continuous nebulization with the Small Particle Aerosol Generator (SPAG). Clinical data suggest that the SPAG is an efficient nebulizer for ribavirin; it is also being used for the delivery of other pulmonary agents.The efficiency of a nebulizer can be defined in large part by delivering a major proportion of its output with a particle size of 1 to 5 μm which is small enough to penetrate the tracheobronchial tree.We assessed both the quality and quantity of the SPAG aerosol cloud with the aid of a multistage liquid impinger, utilizing 2% ribavirin and 1% cromolyn sodium solutions. The aerosol of either solution had a mass median aerodynamic diameter (MMAD) of approximately 1.2 μm, and this seemed insensitive to solution strength and nebulization period. Of the solutions of ribavirin and cromolyn sodium 92.3% and 95.0%, respectively, by weight of delivered particles, had aerodynamic diameters less than 5 μm and about 70–75% of the aerosol particles had an aerodynamic diameter in the 1–5 μm range. This implies that the aerosol cloud is adequate for delivery through a ventilator circuit. Performance was maintained over long (16 hours), continuous periods of delivery. The SPAG could be useful for delivery of other respiratory drugs by continuous nebulization. Pediatr Pilmonol. 1989; 7:183–188.
Effects of acute viral respiratory tract infections in patients with cystic fibrosis
Authors: Hordvik Nancy L. , König Peter , Hamory Bruce , Cooperstock Michael , Kreutz Cynthia , Gayer Debra , Barbero Giulio 
Published: March 2007

AbstractTo determine the effects of acute viral respiratory infections (ARI) in cystic fibrosis (CF) we studied all episodes of ARI in ten patients over a 2 year period. A daily diary card was kept on which they recorded all illnesses, including specific upper and lower respiratory symptoms, antibiotic use, and daily peak flow measurements. Recording of concurrent similar illnesses in other household members aided in confirming the onset of ARI, as did a home viral culturing technique and serial serum antibody levels against specific viral types. A total of 80% of the 35 recorded onsets of ARI (1.75/yr/subject) were confirmed by one or more of these methods. Five subjects with moderate to severe pulmonary function scores at the outset of the study had significantly greater decreases in PEFR during ARI episodes (42.4%) than those with milder disease (15.4%), and it took them significantly longer to recover to their baseline measurements (22 days vs. 15 days respectively). The majority of hospital admissions for pulmonary exacerbations were preceded by viral infections (7/8). Pediatr Pulmonol 1989; 7:217–222.
Genioglossal recruitment during acute hypoxia and hypercapnia in kittens
Authors: Watchko Jon F. , Klesh Kenneth W. , O'Day Terrence L. , Weiss Marc G. , Guthrie Robert D. 
Published: March 2007

AbstractWe examined genioglossal and diaphragmatic EMG activities in one‐ and two‐month‐old anesthetized kittens during acute exposures to hypoxic (13% or 10% O2) and hyperoxic hypercapnic (8% CO2/50% CO2/balanced N2) gas mixtures. Phasic genioglossal EMG activity, frequently characterized by a combined inspiratory‐expiratory discharge pattern, was observed in 3 of 8 one‐month‐old vs. 7 of 7 two‐month‐old kittens during hypercapnia (Chisquare P<0.05). The percentage of kittens recruiting genioglossal activity during hypoxic exposures was similar at both ages (1 month, 75%; 2 month, 83%). Analysis of the breath‐by‐breath response during trials of hypoxia in which genioglossal recruitment was observed, however, revealed that the one‐month‐old kittens exhibited phasic genioglossal activity in only 40±27% of the stimulated breaths, compared to 63±26% for the two‐month‐old ones (P<0.05) at each level of hypoxia. In this regard, the genioglossal response to hypoxia in one‐month‐old kittens was frequently characterized by early and only transient recruitment (when diaphragmatic activity was at its peak), while genioglossal recruitment was more sustained in two‐month‐old animals. These data indicate that genioglossal activity in kittens is often recruited during exposures to hypercapnia and hypoxia, and suggest that such recruitment is more frequent with increasing postnatal age. Pediatr Pulmonol 1989; 7:235–243.
Diagnostic value of body plethysmographic parameters in healthy and asthmatic young children is not influenced by breathing frequency
Authors: Buhr Wernfrid , Jörres Rudolf , Knapp Michael , Berdel Dietrich 
Published: March 2007

AbstractIn 16 healthy and 16 asymptomatic asthmatic children (age range 5–8 yr; 8 girls, 24 boys) we studied the influence of breathing frequency on the results and the diagnostic value of body plethysmographic measurements. Airway resistance (Raw), specific airway resistance (SRaw), and thoracic gas volume (TGV) were measured during breathing (or breathing efforts against a closed shutter) at 0.4, 1, and 2 Hz. SRaw was computed by a simplified procedure directly from flow at the mouth vs. box volume‐curves. The diagnostic value of each parameter was assessed as the percentage of correctly classified healthy and asthmatic subjects by means of discriminant analysis. When frequency was increased from 0.4 to 1 and 2 Hz mean TGV rose by 5 and 14% in healthy children and by 11 and 21% in asthmatic children, respectively. From 0.4 to 1 Hz mean Raw decreased by 16% (P = 0.002) in healthy children and by 25% (P = 0.0004) in asthmatic children. The differences in Raw between both groups decreased with frequency (3.5, 1.8, and 1.5 cm H2O·L−1·s at 0.4, 1, and 2 Hz, respectively) and those of TGV increased (0.13, 0.21, and 0.23 L). SRaw showed similar frequency characteristics as Raw. As intra‐group variability changed in parallel with the differences the diagnostic value of the parameters remained constant with frequency. Simplified SRaw alone and TGV combined with Raw exhibited no differences in their diagnostic values (81–84% correctly classified). Our results indicate that in young healthy and asthmatic children the diagnostic value of TGV, Raw, and SRaw is not influenced by breathing frequencies (0.4–2 Hz) and that in these children the simplified computation of SRaw can be used without loss of information. Pediatr Pulmonol 1990; 8:23‐28.
Comparison of transthoracic impedance/heart rate monitoring and pulse oximetry for patients using diaphragm pacemakers
Authors: Marzocchi Mirella , Brouillette Robert T. , Weese‐Mayer Debra E. , Morrow Anna S. , Conway Linda P. 
Published: March 2007

AbstractPatients using diaphragm pacemakers have several respiratory‐related problems placing them at high risk for death during sleep, including central hypoventilation, abnormal arousal responses, upper airway and/or tracheostomy obstruction, and, in the case of high quadriplegia, lack of motor response to airway obstruction. The recent death from airway obstruction of a patient using diaphragm pacemakers prompted us to re‐evaluate both the need for home monitoring and the type of monitor to prescribe. We compared the performance of a transthoracic impedance/heart rate (TI/HR) monitor with that of a pulse oximeter in six patients with central hypoventilation syndrome whose treatment included diaphragm pacing. Polygraphic recordings of airflow, ECG, Sa02, transthoracic impedance, heart rate, and breath detection were obtained during brief tracheostomy occlusion during patient sleep. Although none of 13 occlusions was detected by the TI/HR monitor, the pulse oximeter identified 13 of 13 occlusions. Three reasons for TI/HR monitor failure included 1) the breath detection circuit consistently registered a breath with each obstructed, paced diaphragmatic contraction; 2) bradycardia did not occur during any airway occlusion; and 3) pacemaker stimuli were misinterpreted as additional heart beats, increasing apparent heart rate. Thus, pulse oximetry, but not TI/HR monitoring, can detect life‐threatening airway obstruction in children using diaphragm pacemakers. Pediatr Pulmonol 1990; 8:29‐32.
Relationship between infant lung mechanics and childhood lung function in children of very low birthweight
Authors: Chan K. N. , Wong Y. C. , Silverman M. 
Published: March 2007

AbstractTwenty‐seven children of very low birthweight (≤1,500 g) whose lung function had been measured on several occasions during the first year were studied at the age of about 9 years. Fifteen of the children had received neonatal intermittent positive pressure ventilation, mostly for respiratory distress syndrome. Ten of the ventilated children were still oxygen dependent at 30 days of age.Compared to the remainder of the group, mechanically ventilated children had reduced lung compliance in early infancy and increased thoracic gas volume in the middle of their first year. These changes correlated with the level of neonatal respiratory therapy as indicated by the oxygen score. Lung compliance in early infancy, but not thoracic gas volume, correlated with forced expiratory volume at 1 second recorded at 9 years. On the other hand, reduced airway conductance showed no significant correlation with the neonatal oxygen score, but there was a strong correlation between airway conductance late in infancy and lung function at 9 years. This relationship was independent of neonatal mechanical ventilation.We conclude that perinatal factors, which may be associated with disturbed lung mechanics early in infancy, are only weak and indirect predictors of childhood lung function. Airway conductance late in infancy, determined by constitutional factors, prematurity itself or other undetermined factors, is a good predictor of airway function at 9 years. Pediatr Pulmonol 1990; 8:74‐81.
Does lithium carbonate affect the ion transport abnormality in cystic fibrosis?
Authors: Anbar Ran D. , Lapey Allen , Khaw Kon‐Taik , Spragg Jocelyn , Strieder Denise J. , Shaw Lisa F. , Kelly Dorothy H. , Shannon Daniel C. 
Published: March 2007

AbstractLithium is known to affect several aspects of cellular regulation which may be related to ion channel function in epithelial cells. To determine whether the ion transport abnormality in cystic fibrosis (CF) is affected by lithium with resultant changes in clinical status, 36 CF patients, 12–37 years old, were enrolled in a 14 week, double‐blind, placebo‐controlled trial. Eighteen patients were randomly assigned to receive lithium carbonate for 10 weeks. At the end of therapy their average serum lithium concentration was 0.56 ± 0.06 mmol (SEM) per liter. Their sweat chloride concentration fell from 92.1 ± 4.8 mmol per liter to 87.4 ± 4.0 mmol per liter after 10 weeks of therapy (P = 0.07) and rose to 94.4 ± 3.5 mmol per liter 4 weeks after end of therapy (P < 0.001 compared to results at end of therapy). Their forced vital capacity (FVC) fell from 72 ± 5.3% of predicted to 66 ± 5.1% of predicted after 4 weeks of therapy (P < 0.01), and their forced expiratory volume in one second (FEV1) fell from 56 ± 5.5% of predicted to 51 ± 5.5% of predicted after 4 weeks of therapy (P < 0.01). In a non‐blind assessment, performed 19 weeks after the end of therapy, their FVC and FEV1 had risen and were not significantly different from baseline. Sweat chloride, FVC, and FEV1 remained unchanged in the placebo group throughout the period of study.We conclude that in patients with CF lithium affects the function of the lungs and sweat glands, two organ systems in which the CF epithelial cell defect is well recognized. Several mechanisms could account for these lithium effects. Since pulmonary function deteriorated during short‐term lithium administration, lithium as used in this study has no therapeutic value in CF and pulmonary function must be closely monitored when lithium is used for manic‐depressive disease in patients with CF. Pediatr Pulmonol 1990; 8:82‐88.
Transcutaneous blood gas analysis during sleep and exercise in cystic fibrosis
Authors: Pradal U. , Braggion C. , Mastella G. 
Published: March 2007

AbstractForty patients with cystic fibrosis (CF) (mean age, 13 ± 2.5 years) were studied with transcutaneous (tc) blood gas monitoring (TCM) during sleep and exercise. By comparing arterial blood samples and TCM in 24 of them (27 samples), a mean bias of tc–15.91 mmHg with a precision of 8.4 mmHg was found. The mean bias of tc was 7.21 mmHg with a precision of 3.9 mmHg. A standardized submaximal exercise test (1.7 W/kg) was performed in all 40 CF patients and in 14 healthy control subjects (mean age, 13 ± 0.5 years). The typical tc trend during exercise for CF and healthy subjects was a slight increase of tc levels and tc stability. A minor decrease of tc values occurred in four CF patients (no greater than 7 mmHg). In 28 patients (mean age, 13 ± 3 years), tc and tc were recorded during sleep. In 13 of them, apparent hypoxemic episodes were noted, without relation to the degree of airway obstruction. There were simultaneous episodes of hypercapnia in ten patients. Some difficulties were encountered in analyzing long‐term recordings. Tc drifts upward and tc decreases during the recordings over several hours. The change in electrode position after 4 h of sleep modified tc and tc values. Such difficulties limit the usefulness of long‐term but not short‐term recordings. Pediatr Pulmonol 1990; 8:162‐167.
Model systems for learning pediatric flexible bronchoscopy
Authors: Wood Robert E. , Pick James R. 
Published: March 2007

AbstractConsiderable practice is necessary to develop the skills essential to successful and safe performance of flexible bronchoscopy, especially in pediatric patients. We review a number of model systems, both mechanical and living, for learning and maturing bronchoscopic skills. For each of the animal models (canine, feline, leporine, and simian), the relevant anatomy and anesthetic techniques as well as the relative advantages and disadvantages of each model are discussed. Pediatr Pulmonol 1990; 8:168‐171.
Monocytes in cystic fibrosis: Responsiveness to microbial stimuli
Authors: Thomassen Mary Jane , Barna Barbara P. , Farmer Mark O. , Doershuk Carl F. , Stern Robert C. 
Published: March 2007

AbstractPeripheral blood monocytes were obtained from 19 patients with cystic fibrosis (CF) and age‐matched paired normal individuals. The oxidative metabolic response of these cells was measured by superoxide anion production before and after stimulation with Salmonella typhimurium or Pseudomonas aeruginosa lipopolysaccharide (LPS). CF monocytes showed slightly greater spontaneous superoxide anion production (14.1 ± 2.1 SEM nanomoles superoxide anion/ 106 monocytes/180 min; n = 12) than normal monocytes (9.5 ± 1.4; n = 12), P = 0.009. No differences between CF and normals were found in LPS‐stimulated superoxide anion production (CF = 33.5 ± 4.6, n = 13; normal = 33.8 ± 4.2, n = 13). Furthermore, CF monocytes responded to both P. aeruginosa and S. typhimurium LPS stimulation as well as to recombinant interferon‐gamma. Superoxide anion production of CF monocytes was comparable in autologous serum and in normal serum, and responses of patients colonized with P. aeruginosa and P. cepacia did not differ. We conclude that CF monocytes have a slightly increased metabolic level and, despite chronic infection, are capable of a further response to exogenous microbial stimuli. Pediatr Pulmonol 1990; 8:178‐181.
Effect of spontaneous and mechanical breathing on dynamic lung mechanics in hyaline membrane disease
Authors: Mammel Mark C. , Fisher Joel B. , Bing Dennis R. , Gatto Catherine W. , Boros Stephen J. 
Published: March 2007

AbstractWe measured then compared the dynamic lung mechanics of spontaneous breaths and mechanical breaths in 9 mechanically ventilated neonates with hyaline membrane disease. All were receiving intermittent mandatory ventilation. All breathed spontaneously between ventilator breaths. Tidal volume, transpulmonary pressure, dynamic lung compliance, airways resistance, and peak inspiratory and peak expiratory gas flows were determined for both the mechanical and the spontaneous breaths. The mechanical breaths consistently had larger tidal volumes, higher transpulmonary pressures, higher airway resistance, and lower lung compliance values (P < 0.05). Peak inspiratory and expiratory gas flows were also higher (P < 0.01) during mechanical breathing. The spontaneous breaths generated by patients and the mechanical breaths generated by mechanical ventilators are different. The lung mechanics measurements of these two different types of breathing should be collected, analyzed, and reported separately. Pediatr Pulmonol 1990; 8:222‐225.
Neonatal gastric intubation: Differential respiratory effects between nasogastric and orogastric tubes
Authors: Greenspan Jay S. , Wolfson Marla R. , Holt William J. , Shaffer Thomas H. 
Published: March 2007

AbstractThe acute effects of nasogastric (NG) and orogastric (OG) tube placement on pulmonary function of neonates was assessed as a function of infant weight. Lung function was obtained on 14 healthy infants weighing less than 2 kg and 10 infants heavier than 2 kg with an NG and an OG tube in place. Additionally, 15 infants were studied for a third time without gastric intubation. Lung function was determined with an esophageal balloon and by pneumotachography (PeDS™) via the least mean square analysis technique. Neither the below‐2 kg infants nor the above‐2 kg infants had apparent clinical compromise with NG and OG tube placement. Infants weighing less than 2 kg, however, demonstrated diminished minute ventilation and respiratory rate and had increased pulmonary resistance, resistive work of breathing, and peak transpulmonary pressure change with NG tube, as compared to OG tube, placement. The above‐2 kg infants demonstrated no change in pulmonary function with NG vs. OG tube placement. These data indicate that small neonates demonstrate significant pulmonary compromise with NG placement that may not be clinically apparent. Pediatr Pulmonol 1990; 8:254‐258.
Methodological aspects of flow‐volume studies in infants
Authors: Turner Debra J. , Morgan Susan E. G. , Landau Louis I. , Lesouëf Peter N. 
Published: March 2007

AbstractAlthough valuable information is being obtained using new techniques to assess infant respiratory mechanics, there have been several concerns about the methodology. These relate to the possibility that chloral hydrate may affect flow‐volume measurements by altering upper airway caliber. There is also the possibility that physiological changes may be induced by inhalation of non‐pharmacologic and pharmacologic nebulized solutions. The aim of this study was to investigate these phenomena in a group of normal infants. Thoracic gas volume was determined and respiratory mechanics measured using the passive and forced expiratory flow‐volume techniques. Respiratory function was assessed in infants before and after 1) sleep was induced by administration of chloral hydrate (n = 10, mean age, 21 weeks); 2) inhalation of nebulized saline (n = 10, mean age, 19 weeks); 3) inhalation of nebulized salbutamol (n = 7, mean age, 22 weeks). A fall in tidal volume was found following administration of chloral hydrate but no significant change was seen in any other respiratory parameter. In addition, no change was seen in any parameter post‐saline or salbutamol nebulization. This study provides data which support several basic assumptions made about the infant flow‐volume techniques and should provide useful background information for future studies using these techniques. Pediatr Pulmonol 1990; 8:289‐293.
Glucocorticoid receptor concentrations in human lung at different growth stages
Authors: Labbe A. , Grizard G. , Dechelotte P. , Raynaud E. J. 
Published: March 2007

AbstractWe measured glucocorticoid receptor concentrations in human lung at different stages of alveolar growth. Lung tissue was obtained from 9 surgically aborted or stillborn fetuses of 15 to 28 weeks gestational age, and from 6 infants and children, aged 2 months to 9 years, after lobar resection or at autopsy. Samples were taken from macroscopically healthy areas. Lung histology was performed in all cases. The receptor assay was done by establishing saturation curves for labeled dexamethasone in the absence or presence of a hundredfold excess of unlabeled dexamethasone. Total binding capacity and the dissociation constant were calculated from the saturation curves by the method of Scatchard. The receptor concentration in the fetuses was high (182 ± 88 fmol/mg prot.), irrespective of gestational age. The lowest concentration (35 fmol/mg prot.) was found in a fetus with pulmonary hypoplasia. In the infants and children the mean receptor concentration was significantly lower (14.6 ± 9.9 fmol/mg prot.); these included a case of sudden death in which the parenchymal structure was normal. Pediatr Pulmonal 1990; 9:140–145.