bluuebunny/crossref_metadata_2025_split huggingface dataset:
Respiratory tract colonization with Pseudomonas aeruginosa in cystic fibrosis: Correlations between anti‐Pseudomonas aeruginosa antibody levels and pulmonary function
Authors: Winnie Glenna B. , Cowan Robert G. 
Published: March 2007

AbstractChronic Pseudomonas aeruginosa respiratory tract colonization in patients with cystic fibrosis is associated with development of antibodies to the organism. In contrast to the protection usually afforded by humoral immunity to a bacterial pathogen, the immune response to P. aeruginosa may help perpetuate infection and contribute to pulmonary damage in cystic fibrosis. To determine if specific anti‐P. aeruginosa antibody levels correlated with pulmonary dysfunction, we measured antibodies to seven P. aeruginosa serotypes, and correlated the geometric mean titer with pulmonary function tests. Patients were divided into groups without P. aeruginosa colonization (n = 20), with recent colonization (n = 20), and with chronic colonization (n = 60). Noncolonized patients had normal pulmonary function or mild obstructive lung disease, and low anti‐P. aeruginosa titers. Pulmonary function tests in recently colonized patients were not different from those of noncolonized patients, but antibody titers were higher. Following colonization FEV1 declined and titers increased rapidly. Patients with chronic colonization had worse pulmonary function and higher titers, but while the former were stable the latter gradually increased. An inverse correlation was found between anti‐P. aeruginosa titer and FVC, FEV1, and FEF25–75 (P < 0.001) in these patients; age was not a factor. The strong correlation between severity of lung disease and anti‐P. aeruginosa titer demonstrates that an exaggerated immune response to P. aeruginosa is associated with pulmonary damage in patients with cystic fibrosis. Pediatr Pulmonol 1991; 10:92–100.
Delivery of aerosolized medication to intubated babies
Authors: Watterberg Kristi L. , Clark Andrew R. , Kelly H. William , Murphy Shirley 
Published: March 2007

AbstractWe studied the delivery of aerosolized cromolyn sodium to intubated babies, and evaluated the effect of changes in delivery techniques. In addition, we compared these results with an in vitro model of aerosol delivery. Cromolyn sodium was used as a marker because once the drug is absorbed, it is excreted unchanged, approximately 50% in urine and 50% in bile. We demonstrated that, in vitro, a conventional, jet‐type nebulizer aerosolized 20.5% of a test dose of cromolyn, and only 5.5% of the dose was recovered after passage through 60 cm of ventilator tubing and an endotracheal tube adapter. This increased to 44.5% nebulized and 19% recovered when the volume nebulized was increased from 2 mL to 5 mL. A submicronic nebulizer aerosolized 40% and delivered 33.5% of the test dose. A 20 mg dose of nebulized cromolyn sodium was used as a test dose in infants, after which urine was collected for 4 hours. Forty‐three urine samples were collected, after the delivery of cromolyn test doses, from nine babies (16–128 days old) intubated for bronchopulmonary dysplasia. Both the jet and submicronic nebulizers were tested in two positions: (1) in place of the ventilator humidifier, and (2) at the endotracheal tube adapter. There were no statistically significant differences in cromolyn delivery for any system configuration. In all situations, means of less than 0.1% of the test dose were recovered in the urine. We estimated that in all cases, < 1% of the test dose (approximately 50–100 μg of cromolyn) had been deposited in the lung. These results show that although the submicronic nebulizer aerosolized cromolyn more efficiently, no additional cromolyn could be detected in infants. We speculate that a significant portion of the smaller particles are exhaled. Pediatr Pulmonol 1991; 10:136–141.
Differential effects of oxygen and barotrauma on lung injury in the neonatal piglet
Authors: Davis Jonathan M. , Dickerson Bryon , Metlay Leon , Penney David P. 
Published: March 2007

AbstractIn order to differentiate the effects of hyperoxia and barotrauma in the pathogenesis of acute neonatal lung injury, piglets were either hyperventilated (Pa, 15–20 torr) for 48 hours with 100% oxygen (Group I), hyperventilated with 21% oxygen (Group II), normally ventilated (Pa, 40–45 torr) with 100% oxygen (Group III), or normally ventilated with 21% O2 (Group IV) and compared to unventilated controls. Pulmonary function was tested, and biochemical indicators of lung injury were analyzed in tracheo‐bronchial aspirates at 0, 24, and 48 hours. Bronchoalveolar lavage fluid was analyzed for surfactant composition and activity at the end of the study. At 48 hours, hyperoxic, hyperventilated piglets had significantly decreased dynamic lung compliance (30%) and increased pulmonary resistance (16%), aspirate cell count (190%), elastase activity (88%), albumin (214%), and total protein (150%) concentration. Qualitative light microscopy showed moderate to severe atelectasis, fibrinous exudate, edema, and inflammation. Normoxic, hyperventilated animals had comparable changes in pulmonary mechanics, but significantly milder cellular, biochemical, and morphologic changes. In hyperoxic, normocarbic animals pulmonary physiologic, cellular, and biochemical variables changed comparably to hyperoxic, hyperventilated animals; the pathologic changes were intermediate between hyperoxic, hyperventilated and normoxic, hyperventilated piglets. Normoxic, normocarbic animals had no significant changes in most variables over 48 hours; on morphologic examination their lungs were similar to unventilated controls and showed only mild edema. Surfactant had normal biophysical activity in all animals. Our results demonstrate that hyperoxia causes more significant physiologic, inflammatory, and histologic changes than barotrauma alone. Future attempts to prevent lung injury in neonates should be directed primarily at oxygen toxicity. Pediatr Pulmonol 1991; 10:157–163.
Airway pressures during crying: An index of respiratory muscle strength in infants with neuromuscular disease
Authors: Shardonofsky Felix Roberto , Perez‐Chada Daniel , Milic‐Emili Joseph 
Published: March 2007

AbstractThe purpose of this study was to assess the strength of the respiratory muscles in 12 infants with neuromuscular disease (age range: 0.17–2.08 years) by measuring the maximal inspiratory and expiratory airway pressures (PImax and PEmax) during crying efforts. Infants were divided into two groups according to their respiratory history. Group A included six infants in stable condition without clinical evidence of respiratory abnormalities, and Group B included six infants with severe generalized muscle weakness and previous respiratory failure. The infants in Group B had been weaned from mechanical ventilation 6 to 14 days before being studied. For infants of Group A, PImax and PEmax values were 77 ± 28 cmH2O and 62 ± 18 cmH2O, respectively; for infants of Group B, they were 38 ± 8 cmH2O and 34 ± 8 cmH2O, respectively. A positive correlation was found between PEmax and body mass percentile. No infant had hypercapnia at the time of the study, and Pa values in infants of Group B were significantly lower than those of Group A. These results suggest that measurements of airway pressures during crying may provide an index of respiratory muscle strength in infants with generalized muscle weakness. Pediatr Pulmonol 1991; 10:172–177.
Benefits and complications of troleandomycin (TAO) in young children with steroid‐dependent asthma
Authors: Flotte Terence R. , Loughlin Gerald M. 
Published: March 2007

AbstractIn nine children with steroid‐dependent asthma, ranging in age from 2 and 11/12 to 14 and 4/12 years, troleandomycin (TAO) was administered at a dose of 250 mg po QD or BID, along with oral methylprednisolone. Both medications were then rapidly changed to a QOD schedule. Baseline daily steroid dosage requirements decreased from 15.3 ± 9.1 mg methylprednisolone to 1.4 ± 0.7 mg (P < 0.01, paired t‐test), and the number of steroid bursts (1–2 mg/kg/day) per year decreased from 12.2 ± 4.8 to 4.1 ± 2.0 (P < 0.01, paired t‐test). There was also a significant decrease in the number of hospitalizations per year from 3.4 ± 4.6 to 0.6 ± 0.7 (P < 0.05, paired t‐test). The incidence of steroid side effects increased, despite the decrease in the amount of steroid required. Specifically, the prevalence of cataracts increased from 11% to 33% (χ2 = 4.5, P = 0.15) and the prevalence of hypercholesterolemia increased from 22% to 78% (χ2 = 16.67, P < 0.001). There was no elevation of serum transaminases in any of our patients on TAO. Although TAO appears to be efficacious, caution is warranted when TAO is considered for use in younger children with steroid‐dependent asthma. Pediatr Pulmonol 1991;10:178–182.
Use of exercise in the management of cystic fibrosis: Short communication about a survey of cystic fibrosis referral centers
Authors: Kaplan Ted A. , Zebranek James D. , McKey Robert M. 
Published: March 2007

AbstractA survey of 47 cystic fibrosis referral centers was conducted to study the use of exercise in the management of patients with cystic fibrosis (CF). A questionnaire with 5 brief questions concerning the prescription and application of exercise therapy was sent to the first 47 centers (38.5%) listed in the 1988 CF Foundation Directory, and 46 (97.9%) were returned. While all but one of the respondents recommend exercise at least to selected patients, and while 80.4% of the centers refer patients to summer camp programs, only 43.5% offer exercise stress testing and only 21.7% offer an exercise program for their patients. Most of the respondents who recommend exercise prescribe aerobic exercise, swimming being the most frequently chosen type. Although there is a large discrepancy between those centers that acknowledge the benefits of exercise and those that have arranged for regularly available exercise services, inroads have been made in utilizing this therapeutic tool for patients with CF. Pediatr Pulmonol 1991; 10:205–207.
Bacterial infection in under school age children with expiratory difficulty
Authors: Korppi Matti , Leinonen Maija , Koskela Markku , Mäkelä P. Helena , Saikku Pekka , Launiala Kari 
Published: March 2007

AbstractSerological evidence of bacterial infection was prospectively studied in less than 6 years old patients during 188 acute episodes of expiratory difficulty requiring hospital treatment. Such evidence indicated by antibody or antigen assays was found in 40 patients (21%). Streptococcus pneumoniae was identified in 25 cases; antigenemia was found in 10, antigenuria in 2 and seroconversion in 14 cases. Seroconversion to nontypable Haemophilus influenzae was found in 9 and to Branhamella catarrhalis in 2 cases. Seroconversion to Chlamydia spp. was demonstrated in 8 patients, but specific tests for C. trachomatis were negative. C‐reactive protein was over 40 mg/L in 35 patients (19%); serological evidence of bacterial infection was present in 14 and absent in 21 of them. Thus, either serological evidence of bacterial infection or an elevated C‐reactive protein was found in 61 of the 188 cases (32%). We conclude that bacterial infection is commonly associated with acute wheezing in children under school age. We suggest that bacterial, as well as viral, infections may trigger an acute obstructive attack in children with reactive airways. Pediatr Pulmonol 1991; 10:254–259.
Predicted values for lung diffusing capacity in healthy children
Authors: Nasr Samya Z. , Amato Patricia , Wilmott Robert W. 
Published: March 2007

AbstractLung diffusing capacity was measured in 92 healthy Caucasian children (52 boys and 40 girls), ranging in age from 6 to 17 years, using the single breath carbon monoxide technique (DLCO). Multiple regression equations were developed to predict the DLCO value. Standing height, gender, weight, and age were significant factors in the prediction of DLCO. Sitting height was not a significant covariate when standing height was in the model, but it could replace standing height in the equation. Equations are presented for the calculation of predicted DLCO in children based on standing or sitting height, age, sex, and weight. Pediatr Pulmonol 1991; 10:267–272.
Doppler echocardiographic evaluation of pulmonary artery pressure in pneumonia of infants and children
Authors: Jun‐Bao Du , Shu‐Zheng Li , Bao‐Lin Wang , Yuan Li 
Published: March 2007

AbstractPreviously, there was insufficient evidence to confirm that pneumonia in infants and children might lead to the development of pulmonary hypertension. Recently, it has been shown that acceleration time corrected for heart rate (ATc) and the ratios of right ventricular preejection period to right ventricular ejection time (RPEP/RVET) and of right ventricular preejection period to acceleration time (RPEP/AT) derived from Doppler echocardiography correlated well with pulmonary artery pressure (PAP). To approach PAP in patients with infantile pneumonia, we measured RPEP/RVET, RPEP/AT, and ATc in 105 infants and children with pneumonia and in 17 controls, using a commercially available 2‐dimensional echocardiograph (Toshiba SSH‐40A) with SDS‐21B Doppler unit. An increase of varying degrees in both ratios and ATc was noted during acute illness and significant differences in ratios RPEP/RVET and RPEP/AT were found among patients with mild, moderate, and severe disease. This suggested that PAP increased to different extents in the acute stage of illness and that the degree of increase was related to the severity of disease. Pediatr Pulmonol 1991; 10:296–298.
Recurrent respiratory infections in a child with fucosidosis: Is the mucus too thin for effective transport?
Authors: Rubin Bruce K. , Macleod Patrick M. , Sturgess Jennifer , King Malcolm 
Published: March 2007

AbstractFucosidosis is caused by a deficiency of the lysosomal enzyme alpha‐L‐fucosidase (ALF) leading to an accumulation of glycoproteins in a variety of cells. Infants and young children with this disorder are prone to recurrent sinus and pulmonary infections and often die of pneumonia. We studied the mucociliary and systemic immune function in a 6 year old girl with fucosidosis and recurrent respiratory infections. All measurements of systemic immune function were normal. Sweat chloride was normal when measured on angiokeratotic skin but was greater than 65 mg/L on uninvolved areas.During the placement of tympanic ventilation tubes, tracheal mucus was gently aspirated and a mucosal biopsy was taken. Tracheal mucus transport was not measured. The biopsy material was examined under phase contrast microscopy and revealed ciliated cells with apparently normal beating. TEM of these cells showed a characteristic pattern of vacuoles in the cytoplasm as described in other tissues from patients with fucosidosis. Ciliary ultrastructure was normal. Mucus viscoelasticity was measured in a magnetic microrheometer. The loss tangent was 2 SD above the mean for normal mucus and mechanical impedance was about 2 SD below the mean. These changes are similar in direction but double in magnitude to what has been described with methacholine administration in dogs. The high compliance of the mucus may be due to incomplete assembly of mucus glycoprotein or to decreased secretion of glycoproteins in respiratory secretions. This leads to mucus that is abnormally watery and thus difficult to clear from the airway. Pediatr Pulmonol 1991; 10:304–309.
Pulmonary mechanics and outcome of neonates on ECMO
Authors: Freezer N. J. , Butt W. , Sly P. D. 
Published: March 2007

AbstractDeciding when to wean neonates from extracorporal membrane oxygenation (ECMO) can be difficult. The usefulness of simple measurements of pulmonary mechanics e.g., dynamic compliance (Cdyn) has been questioned. We investigated the pulmonary mechanics of eight neonates using the interrupter technique, which allows the partitioning of pulmonary mechanics into compartments representing the conducting airways and more peripheral phenomena (viscoelastic properties and “pendelluft”).Three neonates required ECMO for a congenital diaphragmatic hernia (CDH), two for hyaline membrane disease (HMO), two for meconium aspiration syndrome (MAS), and one for pneumonia. All neonates with MAS, HMD, and pneumonia were successfully weaned from ECMO when their Cdyn was 0.3 mL/cmH2O/kg or greater [mean 0.34 ± 0.06 (SEM)]. All three neonates with CDH died and their highest Cdyn was 0.21, 0.19, and 0.09 mL/cmH2O/kg respectively (mean, 0.16 ± 0.037).The airway resistance (Raw) and the slower component of pressure change after interruption (δPdiff), a measure of the more peripheral phenomena of the lung, were not significantly different in those neonates who survived and those who did not. The values for δPdiff in all patients were higher than those in healthy neonates. However, the Raw was not different. This suggests that the major disturbance in pulmonary mechanics was distal to the conducting airways.Those neonates who were successfully weaned from ECMO had a significantly higher Cdyn 24–48 hours prior to decannulation. Considering the lung as a two‐compartment model offers no advantages when compared to the one‐compartment model for the prediction of the outcome of a neonate on ECMO.
Inspiratory time and pulmonary function in mechanically ventilated babies with chronic lung disease
Authors: Goldman Steven L. , McCann Ellen M. , Lloyd Benjamin W. , Yup Gary 
Published: March 2007

AbstractTo learn if increasing inspiratory time would improve pulmonary function in mechanically ventilated babies with chronic lung disease, we measured lung mechanics and alveolar ventilation at three inspiratory times: 0.4, 0.6, and 0.8 s. Nine babies were studied. Their mean birth weight was 875 g (range, 570–1,100 g), gestational age 27 (24–34) weeks, and age 7 (4–12) weeks. Their mean oxygen requirement was 40% (29–53), ventilator rate 33/min (20–40), and mean airway pressure 8 (5–10) cmH2O. Ventilator rate was kept constant; therefore expiratory time decreased and mean airway pressure and I:E ratio increased at longer inspiratory times. At 0.6 s and 0.8 s, when compared to 0.4 s, significant increases occurred in tidal volume (10.4, 10.1, and 8.4 mL/kg, respectively), dynamic lung compliance (0.68, 0.68, and 0.53 mL/cmH2O/kg, respectively), and alveolar ventilation (6.0, 6.3, and 4.7 mL/kg/breath, respectively). Airway resistance, anatomical dead space to tidal volume ratio, and functional residual capacity were similar at the three inspiratory times. Our findings suggest that an inspiratory time ⩾0.6 s (compared to 0.4 s) increases the effectiveness of mechanical ventilation for babies with chronic lung disease.
Relationship of symptoms to lung function abnormalities in preterm infants at follow‐up
Authors: Yuksel B. , Greenough A. 
Published: March 2007

AbstractRecurrent respiratory symptoms are common in preterm infants in the first 2 years of life. The aim of this study was to determine the lung function abnormalities associated with such symptoms. Forty preterm infants, with a median gestational age of 29 weeks were studied at a median postnatal age of 12 months. Twenty‐two suffered from recurrent symptoms, defined as wheezing and/or coughing on at least 4 days per week over the previous month. Lung function was assessed by measurement of functional residual capacity (FRC), using a helium gas dilution technique, and airway resistance (Raw) and thoracic gas volume (TGV) plethysmographically. No significant difference was found in TGV between symptomatic and asymptomatic infants, but the median FRC was lower (P < 0.01), Raw higher (P < 0.01), and FRC:TGV ratio lower (P < 0.001) in the symptomatic infants. These lung function abnormalities in the symptomatic infants are suggestive of gas trapping.
Comparison of FEV1and transcutaneous oxygen tension in the measurement of airway responsiveness to methacholine
Authors: van Broekhoven P. , Hop W. C. J. , Rasser E. , de Jongste J. C. , Kerrebijn K. F. 
Published: March 2007

AbstractThe measurement of airway responsiveness in preschool children is hampered by the fact that most tests of airway caliber are difficult to carry out at a young age. Patient cooperation is only needed to a limited extent when transcutaneous oxygen tension (Ptc) is used as an indicator of airway obstruction following bronchial provocation.In 51 children, aged 6–14 years with asthma we have measured Ptcand forced expiratory volume in 1 second (FEV1) concurrently after bronchial provocation, using increasing doses of methacholine administered with a De Villbiss 646 nebulizer and a French‐Rosenthal dosimeter.The shapes of the dose‐response curves to Ptcand FEV1show a close similarity. After methacholine challenge, the decrease in Ptccorrelates highly with the decrease in FEV1.We conclude that in children a 20% decrease in Ptccan be used as a sensitive indicator of airway narrowing after methacholine challenge.
Effect of nasal CPAP on thoracoabdominal motion in neonates with respiratory insufficiency
Authors: Locke Robert , Greenspan Jay S. , Shaffer Thomas H. , Rubenstein S. David , Wolfson Marla R. 
Published: March 2007

AbstractThoracoabdominal motion (TAM) profiles were determined in ten infants requiring nasal continuous positive airway pressure (CPAP) and supplemental oxygen, in order to assess the influence of CPAP on chest wall function in infants with respiratory insufficiency. (TAM) was quantitated by respiratory inductive plethysmography, measuring relative motion of the rib cage and abdomen. Baseline pulmonary function (without CPAP support) was assessed from simultaneous measurements of transpulmonary pressure, air flow, and tidal volume. Measurements of (TAM) were acquired at baseline and at nasal CPAP levels of 0, 3, 5, and 8 cm H2O, in randomized order. Without CPAP, relative paradoxical motion occurred, i.e., the rib cage collapsed inward instead of expanding outward early in inspiration. With CPAP, TAM resembled the pattern in preterm infants, without lung disease. We found that nasal CPAP lowers the phase angle in infants with respiratory insufficiency (P < 0.003), indicating improved synchrony of TAM. In addition, the improvement with nasal CPAP was related to the severity of pulmonary compromise at baseline. We speculate that changes in TAM associated with nasal CPAP arise from an interaction between pulmonary mechanics and an enhanced stability of the chest wall. In this context, the greater synchrony of TAM is suggestive of an improved breathing strategy. This may be a noninvasively obtainable marker of an effective nasal CPAP level in infants with altered pulmonary and chest wall mechanics.