Management of acute pulmonary hemorrhage in children.

OBJECTIVE: Acute pulmonary hemorrhage can result from a variety of causes. This report offers a diagnosis and treatment plan for children with acute, life-threatening pulmonary hemorrhage resulting from a variety of causes. METHODS: Retrospective review of children with acute pulmonary hemorrhage cared for at a tertiary care children's hospital during from January 1, 1993 to September 1, 1999. PATIENTS: Fourteen children were identified with life-threatening pulmonary hemorrhage during the study period. INTERVENTIONS: Bronchoscopy was the keystone to diagnosis of pulmonary hemorrhage in this series. All of the children underwent multiple procedures to stabilize the airway and control blood loss. These interventions included CO2 laser bronchoscopy, Nd-YAG laser bronchoscopy, endoscopic balloon occlusion of a lobe or main bronchus, topical airway vasoconstrictors, endoscopic tumor excision, transcatheter embolization of bronchial vessels, and lobectomy. OUTCOMES: Three children died and 11 survived without neurological sequelae. CONCLUSIONS: Control of acute pulmonary hemorrhage is a difficult problem and often requires multiple procedures. Endoscopic control is usually required for palliation until more definitive therapy can be undertaken.

Potential to prevent carbon dioxide rebreathing of commercial products marketed to reduce sudden infant death syndrome risk.

OBJECTIVE: Rebreathing of exhaled air is one proposed mechanism for the increased risk for sudden infant death syndrome among prone sleeping infants. We evaluated how carbon dioxide (CO(2)) dispersal was affected by a conventional crib mattress and 5 products recently marketed to prevent prone rebreathing. SETTING: Infant pulmonary laboratory. EQUIPMENT: An infant mannequin with its nares connected via tubing to an 100-mL reservoir filled with 5% CO(2). The sleep surfaces studied included: firm mattress covered by a sheet, Bumpa Bed, Breathe Easy, Kid Safe/Baby Air, Halo Sleep System, and Sleep Guardian. The mannequin was positioned prone face-down or near-face-down. The sleep surfaces were studied with the covering sheet taut, covering sheet wrinkled, and with the mannequin arm positioned up, near the face. MEASUREMENTS: . We measured the fall in percentage end-tidal CO(2) as the reservoir was ventilated with the piston pump. The half-time for CO(2) dispersal (t(1/2)) is an index of the ability to cause or prevent rebreathing. RESULTS: Compared with the face-to-side control, 5 of 6 surfaces allowed a significant increase in t(1/2) in all 3 prone scenarios. The firm mattress and 4 of the 5 surfaces designed to prevent rebreathing consistently allowed t(1/2) above thresholds for the onset of CO(2) retention and lethal rebreathing in an animal model (J Appl Physiol. 1995;78:740). CONCLUSIONS: With very few exceptions, infants should be placed supine for sleep. For infants placed prone or rolling to the prone position, significant rebreathing of exhaled air would be likely on all surfaces studied, except one.

Reconstructive spine surgery in pediatric patients with major loss in vital capacity.

Thirty-two pediatric patients with severe restrictive lung disease identified with vital capacities < 40% of predicted, who had undergone major reconstructive spine surgery, were reviewed. There were 18 boys and 14 girls, the mean age was 13 years (range, 7-17), and the mean vital capacity was 31% of predicted (range, 16-39%). Fifty-four procedures were performed, 13 posterior only, one of which was staged, and 19 anterior and posterior procedures, of which 15 were staged and four were sequential. The incidence of pulmonary complications (pneumonia, reintubation, pneumothorax, respiratory arrest, or the need for tracheostomy) was 19% (six patients), and only three patients required tracheostomy. The surgical and perioperative mortality rate was zero. Patients who had a thoracotomy or a thoracoabdominal approach had a significantly higher number of pulmonary complications. The use of preoperative decreased vital capacity as a measure of inoperability excludes the young patient most in need of surgical intervention. With improved preoperative, intraoperative, and postoperative techniques, careful monitoring, and the cooperation of pediatric pulmonologists and intensivists, reconstructive spine surgery can be performed in the pediatric patient with severe decreased vital capacity with very acceptable morbidity and mortality.

Chronic respiratory failure of infancy and childhood: clinical outcomes based on underlying etiology.

To assess whether underlying diagnosis affects morbidity and mortality outcomes in patients with chronic respiratory failure, we studied 55 patients with chronic respiratory failure of infancy and childhood (CRFIC). Entry criteria included patients with chronic respiratory failure due to static neurologic or neuromuscular conditions or secondary to other disease processes considered likely to improve or resolve over time. Subjects were grouped into those having chronic lung disease (CLD, n = 22), neurologic or neuromuscular diseases (NM, n = 21), or congenital abnormalities affecting the respiratory system (CA, n = 12). The average duration of follow-up was 21.3 months. There were no differences between groups in mortality with only four deaths (7%). Patients with CLD fared better than those with NM or CA in duration of ventilatory support, duration of tracheostomy, percentage of successful weaning from mechanical ventilation, and neurodevelopmental outcomes. Subjects with CLD had a significantly greater frequency of tracheomalacia (86%), feeding disorders (86%), and hypogammaglobulinemia G (77%). There were no differences between groups for respiratory readmissions or family dysfunction. We conclude that almost all patients with CRFIC will survive, but morbidity outcomes will vary based on the underlying diagnosis.

Genotoxicity studies of the reaction of chlorine or chlorine dioxide with L-tryptophan.

Non-volatile reaction products generated from the reactions of 70 mM aqueous chlorine or chlorine dioxide with 10 mM L-tryptophan were shown to be direct-acting mutagens to Salmonella typhimurium TA100 and TA98. Several of the fluorescent bands obtained after thin-layer chromatographic fractionation of the XAD-2/8 resin concentrates of the reaction mixtures were shown to be more mutagenic than the reaction mixtures using the Ames Salmonella/microsome assay. In addition, these fractions were shown to be capable of increasing significantly the frequency of sister chromatid exchange in Chinese hamster ovary cells in the absence of rat liver S9 mix. GC/MS analysis of the products in a highly mutagenic fraction of the aqueous chlorine reaction products identified 1,1,3-trichloropropanone, 1,1,3,3-tetrachloropropanone and dichloroquinoline.

Bronchopulmonary dysplasia: radiographic appearance in middle childhood.

Chest radiographs were compared for three groups of children 8-9 years old: 23 survivors of bronchopulmonary dysplasia (BPD), 33 survivors of hyaline membrane disease without BPD, and 35 survivors of premature birth without neonatal respiratory problems. Only four children in the second group and three in the third had abnormal lungs. Linear shadows, apparently representing strands of fibrosis or deep pleural fissuring, were seen more frequently (15 of 23) in the BPD group than in the others (P less than .0001). Seventeen children in the BPD group had definite pulmonary abnormalities, none of them severe. The anteroposterior dimension of the chest in survivors of BPD tended to be decreased (P less than .001 vs that of reported control subjects).

Isolation of a methyl parathion-degrading Pseudomonas sp. that possesses DNA homologous to the opd gene from a Flavobacterium sp.

Two mixed bacterial cultures isolated by soil enrichment were capable of utilizing methyl parathion (O,O-dimethyl O-p-nitrophenylphosphorothioate) and parathion (O,O-diethyl O-p-nitrophenylphosphorothioate) as a sole source of carbon. Four isolates from these mixed cultures lost their ability to utilize the pesticides independently in transfers subsequent to the initial isolation. One member of the mixed cultures, a Pseudomonas sp., however, hydrolyzed the pesticides to p-nitrophenol but required glucose or another carbon source for growth. The crude cell extracts prepared from this bacterium showed an optimum pH range from 7.5 to 9.5 for the enzymatic hydrolysis. Maximum enzymatic activity occurred between 35 and 40 degrees C. The enzyme activity was not inhibited by heavy metals, EDTA, or NaN3. Another isolate from the mixed cultures, a Flavobacterium sp., used p-nitrophenol for growth and degraded it to nitrite. Nitrite was assimilated into the cells under conditions during which the nitrogen source was excluded from the minimal growth medium. The hybridization data showed that the DNAs from a Pseudomonas sp. and from the mixed culture had homology with the opd (organophosphate degradation) gene from a previously reported parathion-hydrolyzing bacterium, Flavobacterium sp. The use of the opd gene as a probe may accelerate progress toward understanding the complex interactions of soil microorganisms with parathions.

Reaction of chlorine dioxide with amino acids and peptides: kinetics and mutagenicity studies.

Chlorine dioxide (ClO2) is currently being considered as an alternate to chlorine as a disinfectant for water treatment. Many organic compounds present in water and food treated with ClO2 are subject to oxidation. 21 amino acids and 3 peptides (L-aspartyl-L-phenylalanine methyl ester (aspartame), L-glycyl-L-tryptophan and L-tryptophylglycine) were studied for their reactivity with ClO2. Chlorine dioxide reacted only with 6 amino acids in 0.1 M sodium phosphate buffer, pH 6.0. The reaction with cysteine, tryptophan and tyrosine was too rapid to be monitored either iodometrically or spectrophotometrically. The reaction with histidine, hydroxyproline and proline was found to be pseudo-first order. ClO2 readily reacted with L-glycyl-L-tryptophan and L-tryptophylglycine but not with aspartame. Mutagenicity studies with the Salmonella microsome assay of the reaction mixtures of ClO2 with those 6 reactive amino acids and the 3 peptides indicated that the reaction products of the 3 peptides, hydroxyproline, and tyrosine exerted mutagenic activity toward both tester strains of TA98 and TA100 in the presence and absence of rat-liver S9 mix.

Reactions of aqueous chlorine and chlorine dioxide with model food compounds.

Chlorine and chlorine dioxide (ClO2), common disinfecting and bleaching chemicals used in the food industry, are potent oxidizing and chlorinating agents. Unfortunately, little is known about the nature of the reactions of chlorine with organic food constituents. This presentation reviews published information concerning the reactions of chlorine gas (Cl2[g]), aqueous chlorine, and ClO2 with model food compounds, the fate of chlorine during the chlorination of specific food products, and the potential toxicity of the reaction products. Fatty acids and their methyl esters react with chlorine with the degree of incorporation corresponding to their degree of unsaturation. Aqueous chlorine oxidizes and chlorinates lipids and amino acids much more readily than ClO2. Several amino acids are highly susceptible to oxidation and chlorination by chlorine compounds. Reactions of chlorine and ClO2 with several food products, including flour and shrimp, have also been characterized. In one model system, 99% of Cl2(g) either reacted with components of flour or was consumed by oxidation/chlorination reactions. The lipids extracted from the chlorinated flour contained significant amounts of chlorine. Exposure of shrimp to hypochlorous acid (HOCl) solution resulted in significant incorporation of chlorine into the edible portion. Although significant quantities of chlorine can be incorporated into specific model compounds and food products, the health risks associated with exposure to chlorinated organic products are unknown. Preliminary studies using the Ames Salmonella/microsome mutagenicity assay indicate that the reaction products from mixtures of aqueous chlorine and various lipids or tryptophan are nonmutagenic. Nevertheless, additional studies are warranted, so that the toxicological significance of these reaction products can be understood more fully.

Electron capture gas chromatographic determination of thiabendazole in yams.

A method for the determination of thiabendazole in yams is reported. The method consists of extracting the chopped crops with ethyl acetate followed by distilled water wash and liquid liquid extraction of the chemicals into dilute hydrochloric acid. The sample is further cleaned up by making the aqueous acidic fraction alkaline and repartitioning into ethyl acetate. The determination step includes evaporation of the cleaned up extract to dryness, derivatization with pentafluorobenzoyl chloride, and determination of the derivatized thiabendazole in acetone by gas chromatography with electron capture detection.

Capillary gas chromatographic determination of terbutryn and its degradation products in sorghum grain and confirmation of the compounds by mass spectrometry.

An analytical method with a limit of detection 0.05 mg kg-1 is described for the determination of the herbicide terbutryn and its three degradation products, GS-26575, GS-11355 and GS-26831 in sorghum grains using fused silica capillary gas chromatography. Electron impact and methane chemical ionization mass spectra are reported to confirm the characterization of the compounds. No residues of these chemicals were found in sorghum harvested 14 weeks following terbutryn treatment at 0-4.5 kg ha-1.

Capillary gas chromatographic determination of prometryn and its degradation products in parsley.

Residue analysis of the herbicide prometryn (2,4-bis(isopropylamino)-6-methylthio-1,3,5-triazine) is widely known, but an analytical method for determining its metabolities or degradation products in addition to the parent chemical has not yet been reported in the literature. The procedure reported here is for the extraction and determination of prometryn and 2 metabolites, 2-amino-4-isopropylamino-6-methyl-thio-1,3,5-triazine and 2,4-diamino-6-methylthio-1,3,5-triazine, in parsley. Crops were extracted with 2-propanol followed by concentration of the extract and partitioning with a minimum amount of hexane in the presence of a large excess of water to remove most of the green pigment. The aqueous phase was divided into 2 equal halves: (A) One-half portion was partitioned with dichloromethane in the presence of saturated sodium chloride solution, the dichloromethane phase was separated, and the aqueous phase was discarded. The organic solvent was evaporated, and the contents were reconstituted in petroleum ether before prometryn analysis. (B) The other half was made slightly alkaline with ammonium hydroxide solution and was partitioned with ethyl acetate in the presence of saturated sodium chloride solution. The ethyl acetate phase was concentrated, centrifuged to remove any turbidity, and analyzed for the 2 metabolities above. Fused silica capillary gas chromatography (GC) with nitrogen-phosphorus (N-P) detection was used for quantitation. The limit of detection was 0.05 mg/kg for all the compounds examined. Recoveries from fortified parsley samples ranged from 59 to 73% at fortification levels of 0.05 to 1.0 mg/kg.

Gas chromatographic and mass spectrometric determination of ametryn and its N-dealkylated products.

Gas chromatographic and mass spectrometric properties of ametryn and its N-dealkylated products were studied to establish the potential use in a recently reported method describing the residue analyses of these compounds by gas chromatography with N-P detection. Electron impact mass spectra show base peaks at the molecular ion (M+), and methane chemical ionization mass spectra give base peaks at (M + 1) ion for all the compounds studied. Characteristic mass spectral fragmentations of ametryn, GS-11354, GS-11355, and GS-26831 are presented. Combined gas chromatography-mass spectrometry rather than gas chromatography alone provides unambiguous residue characterization. The technique also allows quantitation of ametryn and its N-dealkylated products that cochromatograph with interfering materials present in a complex substrate.

Progression of cystic fibrosis lung disease as a function of serum immunoglobulin G levels: a 5-year longitudinal study.

Seventy children with cystic fibrosis were studied over a 5-year period to assess the relationship between serum immunoglobulin G levels and progression of cystic fibrosis lung disease. Patients were grouped according to their serum IgG values (low, normal, or high) and evaluated with serial pulmonary function testing, radiographic and immunologic studies, and clinical observation. The children with persistent hypogammaglobulinemia G showed significantly better lung function, better weight for age, fewer hospitalizations for pulmonary exacerbations, less colonization with Pseudomonas aeruginosa, and slower decline in pulmonary functions than did age-matched patients with normal or high IgG levels. Death occurred in five of eight (63%) patients with hypergammaglobulinemia, three of 30 (10%) with normogammaglobulinemia, and one of 32 (3%) with hypogammaglobulinemia. No deaths occurred in the 15 patients with persistent hypogammaglobulinemia. These data indicate that children with cystic fibrosis and hypogammaglobulinemia G have milder lung disease and slower deterioration in pulmonary function than do age-matched patients with normal or elevated immunoglobulin G values. The mechanisms accounting for this finding are unclear.

Gas chromatographic determination of ametryn and its metabolites in tropical root crops.

Residue analysis of the herbicide ametryn (2-methylthio-4-ethylamino-6-isopropylamino-s-triazine) is widely known but an analytical method for determining its metabolites has not yet been reported in the literature. A method has been developed for the extraction and determination of ametryn and 3 metabolites, 2-methylthio-4-amino-6-isopropylamino-s-triazine (GS-11354), 2-methylthio-4,6-diamino-s-triazine (GS-26831), and 2-methylthio-4-amino-6-ethylamino-s-triazine (GS-11355) in taniers , yams , cassava. Residues were extracted from crops with ethyl acetate-toluene (3 + 1 v/v), using a Polytron homogenizer and anhydrous sodium sulfate added for drying. The extracts were cleaned up by automated gel permeation chromatography on Bio-Beads SX-3 gel in the same solvent system. Quantitative determination was performed by gas chromatographic (GC) analysis on a column packed with 5% DEGS -PS on 100-120 mesh Supelcoport using either an N-P detector or a flame photometric detector ( FPD ) in the sulfur mode. Minimum detection by the flame photometric detector is 10 ng each for ametryn , GS-11354, and GS-11355 and 21 ng for GS-26831; by the N-P detector, 0.3 ng of each component gives easily quantitatable peaks. On a parts per million basis, starting with 25 g sample, the FPD detected a minimum level of 0.04 microgram/g each for ametryn , GS-11354, and GS-11355, and 0.08 microgram/g for GS-26831. The N-P detector could detect 0.0024 microgram/g for all 4 compounds. In addition to superior sensitivity, instrumental conditions allowed the complete separation of components in 10 min, for the N-P detector; more than 30 min was required for the FPD . Recoveries from fortified crops ranged from 67 to 111% at levels of 0.1-1.0 microgram/g.