William W. Waring

A comparison of cell-mediated immunity and suppressor T-cell function in asthmatic and normal children

The role of general and suppressor T‐cell function was investigated in a group of twelve children with atopic asthma and ten non‐atopic control children. Studies of active E rosettes, lymphocyte stimulation, and delayed type skin responsiveness revealed no statistically significant group differences. Data obtained employing a concanavalin A‐induced, suppressor T‐cell assay revealed that the asthmatics generated significantly less suppressor cell activity than did the normal control group. There was no correlation between lack of suppressor cell function and serum IgE levels. The results of this study support the concept of suppressor T‐cell dysfunction in atopic disease.

Tracheal breath sounds for detection of apnea in infants and children.

Impedance respiratory monitoring is the standard technique for detecting apnea in infants. A miniature microphone/amplifier system has been used to sense breath sounds over the trachea in order to detect both central and obstructive apnea episodes in infants and children. The tracheal microphone has several advantages over other devices that sense airflow (thermistors, CO2 sampling catheters) because it is not easily dislodged during restless sleep. This simple device may be used in monitoring of neonates and infants; it may eventually replace impedance monitoring.

Benign hemangioendothelioma — A rare type of posterior mediastinal mass in children

Two infants with benign hemangioendotheliomas of the posterior mediastinum are reported here. The neoplasms did not produce symptoms and were fortuitously discovered by chest roentgenograms. Computed tomography (CT) was useful in delineating the extent of the lesions preoperatively.

Cell mediated immunity and suppressor T cell function in children with cystic fibrosis

The relationship of general and suppressor T cell function to IgE sensitization was investigated in a group of 12 children with cystic fibrosis (CF) and 10 non-atopic control children. Increased IgE sensitization was noted in the cystic fibrosis group, as measured by increased group mean serum IgE levels and an increased incidence of multiple IgE skin sensitivities. Studies of active E rosettes, lymphocyte stimulation, delayed-type skin responsiveness, and Concanavalin A (Con A) induced suppressor cell function revealed no statistically significant group differences. The results of this study may implicate multiple mechanisms for IgE sensitization.

1798 HIGH DOSE PIPERACILLIN THERAPY IN CHILDREN WITH CYSTIC FIBROSIS

Piperacillin 600 mg/kg/day IV q 4 hrs was administered to fifteen children with cystic fibrosis over ten to fourteen days. Seven of these children also received tobramycin (8–13 mg/kg/day). The sputum titers of pseudomonas isolates from children treated with piperacillin plus tobramycin decreased significantly (p<.01) more than children treated with piperacillin alone. Six of the twenty-one isolates from children treated with piperacillin alone decreased >102 cfu/ml vs 13 of 19 isolates in patients treated with piperacillin and tobramycin (p=0.025). All isolates had MICs to piperacillin of ≤128 mcg/ml prior to therapy. Development of resistance to piperacillin during therapy was not seen.The mean peak serum piperacillin concentration 15 minutes after a 30 minute infusion was 238 mcg/ml. The mean area under the curve was 250–300 micrograms/liter-hour. The mean volume of distribution (400–500 ml/kg) was larger and the t1/2 (0.60 hrs) shorter than reported for normal adults. Toxicity was minimal but included fever in one child and rash on one child.High-dose piperacillin therapy is well tolerated by cystic fibrosis patients. Although piperacillin has enhanced anti-pseudomonas activity, therapy for children with cystic fibrosis should include an aminoglycoside.

1626 PHYSIOLOGICAL CORRELATES OF INTERSTITIAL LUNG DISEASE (ILI)) IN CHILDREN: OXYGEN DESATURATION (DeSaO2) DURING EXERCISE

Young children with ILD may be uncooperative or too ill to perform meaningful tests of pulmonary function. We have evaluated children with ILD using pre, during (DUR), and post exercise (EX) stress ear oximetry (SaO2) and other more routine tests of pulmonary function. Responses in children with ILD, healthy children (CON), those with bronchial asthma (BA), and cystic fibrosis (CF) were compared.* all values represent averages ** standard error of the mean Exercise produced significant DeSaO2 (PRE-DUR) in the ILD, CF, and control groups. The control group DeSaO2 response was minimal. The ILD group exhibited the greatest changes. The alterations in the CF subjects were intermediate in degree. Desaturation responses during exercise clearly separated the ILD group from the others and correlated well with low FVC (R2=.60). Post EX SaO2 values promptly returned to near baseline in most children. We have found DeSaO2 during exercise to be a sensitive, and reproducible test of ILD in children.

1736 CHILDHOOD USUAL INTERSTITIAL PNEUMONITIS (UIP): RESPONSE TO AZATHIOPRINE (AZP) DOCUMENTED BY EXERCISE-STRESS EAR OXIMETRY

Two children aged 6 and 9 years with severe biopsy-proven UIP that was progressing on high dose prednisone were treated with AZP 75-50 mg/day. Sequential determinations of exercise-stress induced changes in oxygen saturation (SaO2%) were measured by oximetry and provided objective evidence of pulmonary improvement. These patients were unable to cooperate in standard pulmonary function tests (PFT).Striking objective evidence of improvement was demonstrated on frequent determinations of forced vital capacity (FVC) and SaO2% determined during exercise. Results at 3 months, 6-9 months are tabulated below:These data indicate that severe progressive childhood UIP with or without auto-allergic features may respond to AZP therapy and that improvement may be reliably quantitated by ear-oximetry during exercise in children unable to cooperate for standard PFT.

1645 NONINVASIVE EVALUATION OF UPPER AIRWAY OBSTRUCTION (UAO) IN CHILDREN

Information obtained from serial inspiratory-expiratory (I/E) flow volume (FV) curves on four children with signs and symptoms or UAO was compared to that obtained by physical examination, bronchoscopy, and airway fluoroscopy in an attempt to evaluate the usefulness of FV curves in young children. FV patterns associated with lesions of the upper airway have been described as fixed (F) UAO, variable intrathoracic (VI) UAO, and variable extrathoracic (VE) UAO.In three of the four cases (Cases 1,2,3) the FV pattern suggested a lesion of the upper airway confirmed by more conventional techniques. In Case 1, fluoroscopy alone confirmed the diagnosis suggested by the FV pattern. I/E FV patterns when combined with airway fluoroscopy, may characterize anatomic lesions of the upper airway frequently missed by less dynamic techniques.

Diagnosing respiratory distress in the newborn.

The word that perhaps best characterizes respiratory distress in the newborn is variability. Included in the wide range of underlying causes are congenital anomalies, infections, hyaline membrane disease, and aspiration syndromes. Differentiation often hinges on a combination of key historical points, the physical examination, the pattern of presenting symptoms, and the chest x-ray film.