Studies on reactogenicity and immunogenicity of attenuated bivalent cold recombinant influenza type A (CRA) and inactivated trivalent influenza virus (TI) vaccines in infants and young children

Fifty-two infants seronegative to or without prior infection with influenza type A viruses were enrolled in a study to evaluate reactogenicity and immunogenicity of three bivalent cold recombinant type A (CRA) and two trivalent inactivated influenza (TI) vaccines. Controls consisted of infants receiving normal saline by nose drops (Pli.n.) or intramuscularly (Pli.m.). CRA and TI vaccines were monitored for local and systemic reactions after vaccination. Serum specimens obtained prior to and 6 weeks postvaccination were analysed for neutralizing antibody to influenza H1N1 and H3N2 viruses. CRA vaccines and Pli.n. recipients had similar numbers of acute respiratory infections and comparable rates of illnesses during the trial. Significantly fewer CRA vaccinees without an intercurrent viral infection had fever (0/16 versus 4/10, p = 0.04) and cough (4/16 versus 9/10, p = 0.002) than CRA vaccinees with a confirmed intercurrent viral infection. Recipients of TI vaccine and Pli.m. did not develop reactions at the injection site. For each of the CRA vaccines tested, a dominant CRA virus was identified. The dominant CRA viruses were isolated from a greater number of infants or for a longer duration than the non-dominant CRA viruses. All 14 non-dominant CRA viruses were recovered from infants within the first week after vaccination; 24 of 77 dominant CRA viruses were recovered more than 7 days after vaccination. The immunogenicity of CRA vaccines was not affected by a confirmed intercurrent viral infection or low titres of influenza-specific antibody.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical spectrum of chronic interstitial lung disease in children

To describe the clinical spectrum of interstitial lung disease in children, we reviewed our experience with 48 patients during a 12-year period. Most patients initially had typical findings of restrictive lung disease and hypoxemia. Growth failure or pulmonary hypertension or both were found in more than one third. Specific diagnosis, made in 35 patients (70%), most often required invasive studies, particularly open lung biopsy. Although the diagnostic yield from open lung biopsy was high, the diagnosis of many patients remained uncertain. Many different disorders were encountered. The response to corticosteroids, bronchodilators, and chloroquine was inconsistent. Six patients died, five within 1 year after the initial evaluation. The spectrum of pediatric interstitial lung disease includes a large, heterogeneous group of rare disorders associated with high morbidity and mortality rates.

Recombinant human G-CSF and retinoic acid in synergistically inducing granulocyte differentiation of human promyelocytic leukemic cells

The effects of recombinant human G-CSF (rhG-CSF) and retinoic acid (RA) were studied on the proliferation and differentiation of HL-60 cells and human acute myeloid leukemic cells. Synergistic effect on granulocyte differentiation was observed when HL-60 cells and primary acute promyelocytic leukemic cells were cocultured with RA plus rhG-CSF. rhG-CSF combined with RA increased more significantly the percentage of mature cells than RA alone and greatly increased NBT reduction activity (P < 0.001). These results suggested that proliferated effect of rhG-CSF on leukemic cells may be important for inducing differentiation of myeloid leukemic cells. But this effect might expose the patients to the risk of acute myeloblastic leukemia if G-CSF was used alone. However, RA could not only rule out the latter situation but retain former merit as well. The authors suggest that the combined use of G-CSF with RA is probably a new approach to the treatment of leukemia.

Protective effect of puerarin against myocardial reperfusion injury. Myocardial metabolism and ultrastructure

To ascertain the beneficial effect of puerarin on the myocardium against reperfusion injury, studies on myocardial metabolism and ultrastructure were made. Twelve dogs divided into two equal groups were placed on moderate hypothermic cardiopulmonary bypass, and their hearts were subjected to 140 minutes cold cardioplegic arrest and 60 minute reperfusion. In the control group, the hearts were perfused with crystalloid cardioplegic solution (CPS) every 20 minutes during arrest. In the treated group, the hearts received CPS containing puerarin (2 mg/kg). Myocardial oxygen consumption, lactate production, creatine phosphokinase (CPK) release, water content and ultrastructural alterations were determined before ischemia, during cardiac arrest and at reperfusion. The results showed that intermittent infusion of CPS containing puerarin significantly decreased myocardial lactate production during ischemia, as well as myocardial oxygen consumption, CPK release and water content during reperfusion. Under electronmicroscopy, the degree of ischemic damage judged by a scoring method was less pronounced in the puerarin group than in the control. The authors conclude that puerarin has protective effects on the function of hearts that have undergone long periods of arrest and reperfusion.

The protective effect of puerarin against myocardial reperfusion injury. Study on cardiac function

In order to find out if puerarin could protect the hearts from myocardial reperfusion injury after cardiac arrest, twelve dogs divided into two equal groups were placed on moderately hypothermic cardiopulmonary bypass and their hearts were subjected to 140 min of cold cardioplegic arrest and 60 min of reperfusion. In the control group, the hearts were perfused with a crystalloid cardioplegic solution (CPS) through the aortic root every 20 min during arrest. In the treated group, the hearts received CPS containing puerarin (2 mg/kg). Cardiac hemodynamic variables were monitored throughout the experiments. Left ventricular function curves were formed before ischemia and after 60 min of reperfusion. The results showed that the recovery of left ventricular function in the treated group was significantly better than that in the controls (81 +/- 11% versus 39 +/- 7%, P less than 0.01). Compared with preischemic values, the increase of coronary blood flow (CBF) at cardiac arrest in the puerarin-treated group was higher than that in the control group (214 +/- 11 versus 177 +/- 4 ml/min, P less than 0.01). The data indicate that puerarin has protective effects on the cardiac function after prolonged arrest and reperfusion.

Diagnosis of tracheal injury in mechanically ventilated premature infants by flexible bronchoscopy. A pilot study

Flexible bronchoscopy (FB) is uniquely suited for the study of large airway lesions in the ventilated premature infant. However, no standardized clinical scoring system of distal tracheal injury exists and the adverse consequences of FB in ventilated premature infants are not well described. Using a prototype Olympus fiberoptic ultrathin bronchoscope with a directable tip and an outer diameter of 2.2 mm, we serially scored distal tracheal injury in conventionally ventilated premature infants on the basis of mucosal and obstructive changes observed at bronchoscopy. In addition, we prospectively evaluated the incidence of adverse cardiovascular and pulmonary effects during, immediately after, and within 1 h of FB. We performed 21 FBs in eight conventionally ventilated premature infants with birth weight of 1,239 +/- 438 g and gestational age of 30 +/- 3 weeks. The carina and mainstem bronchi were easily visualized in all infants using the prototype bronchoscope. During the first several days of life, moderate-to-severe distal tracheal mucosal injury occurred frequently, while moderate-to-severe obstructive injury occurred infrequently. Distal mucosal injury appeared to improve during the fourth week of life. Mild distal obstructive injury began to appear during the second week of life. Adverse consequences of FB observed in our patient population included transient hypoxemia and bradycardia during FB, changes in systolic blood pressure immediately and within 1 h after FB, and emesis immediately after FB. Serious adverse cardiovascular or pulmonary effects were not observed. We conclude that FB can be performed safely with appropriate monitoring and is a useful tool in the clinical assessment and serial evaluation of distal tracheal injury in ventilated premature infants. We speculate that moderate-to-severe distal tracheal mucosal injury may be associated with the development of later obstructive injury. On the basis of this preliminary study, further prospective investigations of tracheal injury in ventilated premature infants appear to be warranted.

The child with simultaneous stridor and wheezing

We describe 25 patients with simultaneous stridor and wheezing. Twelve patients presented to the emergency department of The Children's Hospital of Denver over a two-year period; we found an additional 13 in a review of the literature. A combination of two disorders produced stridor and wheezing in six patients, with one condition in the extrathoracic airway and one in the intrathoracic airway. The remaining 19 patients had single lesions, nine with obstruction of the extrathoracic airway and 10 with obstruction of the intrathoracic airway. The causes of stridor and wheezing in these 19 patients fell into three general categories: (1) congenital lesion affecting the airway (eight patients); (2) foreign body in the airway or esophagus (nine patients); and (3) acquired lesion affecting the airway (two patients). All eight patients with congenital lesions developed symptoms by four months of age. All nine patients with an airway or esophageal foreign body were between five and 30 months of age. The history may be misleading, and the physical examination often cannot discriminate among the various likely diagnoses. However, the addition of four plain x-ray views (lateral neck, posteroanterior and lateral chest, and forced expiratory chest) located the site of obstruction in 18 of 25 patients. Barium swallow identified the two patients with vascular rings. Four patients underwent endoscopy to determine the site of obstruction. We make recommendations for evaluation of these patients.

Paralyzed left vocal cord associated with ligation of patent ductus arteriosus

We reviewed the records of 167 neonates and older children undergoing ligation of a patent ductus arteriosus to determine the prevalence of recurrent laryngeal nerve injury and identify risk factors that might increase the likelihood of injury. Paralysis or paresis of the left vocal cord was identified by fiberoptic laryngoscopy in seven patients. All seven weighted less than 1500 gm at the time of operation and the ductus had been ligated with a metal clip. All had persistent symptoms when observed for 5 to 19 months. Injury to the left recurrent laryngeal nerve occurs infrequently but may have long-term consequences.

Necrotizing tracheobronchitis. An ischemic lesion

Neonates with necrotizing tracheobronchitis present a diverse clinical spectrum from asymptomatic disease to severe airway obstruction. A retrospective clinicopathologic study of 206 neonatal autopsy reports spanning a three-year period yielded 122 cases of necrotizing tracheobronchitis with an incidence of 59%. All study patients received treatment prior to the development of high-frequency ventilator jet, oscillator, or interruption. The site and submucosal depth of airway involvement was variable. The most commonly affected anatomic site was the middle or thoracic trachea (56%). The common cause identified was severe ischemia to the airway mucosa and submucosa, occurring with profound birth asphyxia and/or shock. The presence of ischemia supports the concept that decreased tracheoperfusion may be an important factor in the development of tracheobronchial abnormalities.

Flexible fiberoptic endoscopy for airway problems in a pediatric intensive care unit

We used flexible fiberoptic endoscopy to evaluate 87 patients with potential problems of the airway in a pediatric intensive care unit. Four different-sized bronchoscopes were used to perform 61 diagnostic laryngoscopic procedures, 35 diagnostic bronchoscopic procedures, and eight therapeutic bronchoscopic procedures. Diagnostic information was obtained in 91 of 96 procedures. Of the eight therapeutic procedures, seven were considered successful. Morbidity was minimal, and there was no death. Flexible fiberoptic endoscopy proved useful as a bedside technique for critically ill pediatric patients in whom evaluation of the airway in the operating room under general anesthesia would have been difficult.

Applications of an ultrathin flexible bronchoscope for neonatal and pediatric airway problems

A new 2.7 mm flexible fiberoptic bronchoscope with a directable tip was used to evaluate potential airway problems in 73 pediatric patients. Forty-eight laryngoscopies and 47 bronchoscopies were performed over an 18-month period. Persistent stridor was the most common indication for laryngoscopy; persistent wheezing, the most common indication for bronchoscopy. We obtained diagnostic information in 83 procedures, incidental findings in four, and normal results in eight. There were four complications and no deaths. This instrument enabled patients to be examined who were previously considered too small or who previously required rigid bronchoscopy under general anesthesia.

Apnea of infancy and childhood

Apnea of infancy and obstructive sleep apnea in older children are being more widely recognized as potential causes of morbidity and mortality in children. Much controversy exists surrounding the relationship of apnea of infancy to SIDS and the treatment of apnea in infancy, particularly home monitoring. Obstructive sleep apnea in older children is somewhat better defined, and therapy is generally more definitive.

Transnasal fiberoptic endoscopy in children with obstructive apnea

Eight children with obstructive apnea were evaluated by transnasal fiberoptic endoscopy. Three children had obstructive adenoids and tonsils, 2 had pharyngeal collapse, 1 had an obstructive tongue, and 1 had a subglottic cyst. The remaining patient had no abnormality. The results of transnasal endoscopy influenced therapeutic interventions.

Emergency treatment of foreign-body obstruction of the upper airway in children

Recently, the Committee of Accident and Poison Prevention of the American Academy of Pediatrics presented its recommendations regarding the emergency management of the choking child. Renewed interest was stimulated in the controversy regarding whether back blows, abdominal thrusts, or chest thrusts should be used in the initial treatment of foreign-body obstruction of the upper airway. Two cases exemplifying problems in patient management are presented as a basis of focusing on the current controversy. Review of the clinical and experimental data suggests that back blows, followed by either chest or abdominal thrusts, are a reasonable approach to emergency airway obstruction, but that this recommendation is based on limited evidence.

Risk factors predicting laryngeal injury in intubated neonates

We evaluated 95 extubated neonates to determine if certain risk factors could predict the development of laryngeal injury. Risk factors were recorded prospectively during the intubation period and correlated with laryngeal injury determined by laryngoscopy after extubation. Duration of intubation greater than or equal to 7 days and 3 or more intubations significantly predicted injury.

Predictive value of stridor in detecting laryngeal injury in extubated neonates

We evaluated 73 consecutively extubated neonates for evidence of acute laryngeal injury from intubation. Hoarseness and stridor were graded by a clinical scoring system. Direct laryngoscopy with a flexible fiberoptic bronchoscope yielded a 44% incidence of moderate or major laryngeal injury. All patients with stridor had moderate or major injury, as did 38% of patients without stridor. Stridor was quite specific for detecting moderate or major injury but did not identify the type of injury.

Laryngoscopy in neonates and infants: experience with the flexible fiberoptic bronchoscope

A small flexible fiberoptic bronchoscope was used for laryngeal examination in a series of neonates and infants; 104 laryngoscopies were performed in 59 patients. A high yield of diagnostic information was obtained in both postextubation patients and patients presenting with upper airway obstruction. No major complications were observed. This technique is useful in the evaluation of neonates and infants with potential upper airway problems.