Pulmonary morbidity in 100 survivors of congenital diaphragmatic hernia monitored in a multidisciplinary clinic.

BACKGROUND/PURPOSE: In 1990, the authors began a multidisciplinary follow-up clinic for congenital diaphragmatic hernia (CDH) patients. Although the nonpulmonary complications associated with CDH have been reported previously from this clinic, the purpose of this report is to detail the pulmonary outcome in survivors of CDH with severe pulmonary hypoplasia. METHODS: Between 1990 and 1999, one hundred patients were seen in the clinic. Before hospital discharge, all patients had baseline tests performed, which were repeated per protocol at clinic during follow-up. The data were analyzed by regression analysis to identify and determine the impact of factors on outcomes associated with the long-term pulmonary morbidity. RESULTS: The average birth weight was 3.16 kg (+/-0.7) with a mean Apgar score of 7 (+/- 2) at 5 minutes. Forty-one patients had an antenatal diagnosis performed. Extracorporeal membrane oxygenation (ECMO) was utilized in 29 patients, and a patch repair was required in 32, whereas 16 patients received both. Average time to extubation was 20.7 (+/- 20) days and mean time to discharge was 59.7 (+/- 61) days. Regression analysis showed that both the need for ECMO and a patch repair were independent predictors of delay in extubation (P <. 001, R(2) = 36%), and delay in discharge from the hospital (P =.001, R(2) = 29%). ECMO also was significantly correlated with the need for diuretics at discharge (P <.001, R(2) = 18%), and with the presence of left-right mismatch (P =.009, R(2) = 9%) and V/Q mismatch (P =.005, R(2) = 11%) on subsequent pulmonary ventilation-perfusion examinations. Sixteen patients required O(2) at discharge, and diuretics were necessary in 43 patients. Seventeen patients at discharge required bronchodilators, and during the first year an additional 36 required at least transient therapy. Similarly, 6 patients at discharge required steroids, and an additional 35 patients required at least transient therapy during the first year. Chest x-rays, although frequently abnormal, had little correlation with clinical outcome, but did influence medical therapy. V/Q scans had limited utility in patient management, and the presence of V/Q mismatch was not highly specific for future obstructive airway disease. Nevertheless, V/Q mismatch was sensitive for obstructive airway disease assessed by spirometry. Twenty-five patients over 5 years of age performed pulmonary function tests (PFTs), which showed 72% normal PFT results and 28% with evidence of obstructive airway disease. Before January 1997, 2 of 8 patients who required urgent treatment in the emergency department (ED) were admitted to the intensive care unit (ICU) secondary to acute respiratory distress. After the implementation of respiratory syncytial viral prophylaxis in January 1997, 8 patients were treated in the ED for acute respiratory distress, but none required admission to the ICU. CONCLUSIONS: Pulmonary problems continue to be a source of morbidity for survivors of CDH long after discharge. The need for ECMO and the presence of a patch repair are both predictive of more significant morbidity, but the data clearly show that non-ECMO CDH survivors also require frequent attention to pulmonary issues beyond the neonatal period. These data show the need for long-term follow-up of CDH patients preferably with a multidisciplinary team approach.

Non-hydrogen bonding 'terminator' nucleosides increase the 3'-end homogeneity of enzymatic RNA and DNA synthesis.

We report the use of novel non-polar nucleoside analogues as terminators of enzymatic RNA and DNA synthesis. Standard 'runoff' RNA synthesis by T7 RNA polymerase gives RNA products which have ragged ends as a result of transcription which often extends beyond the end of the template DNA strand. Similarly, the Klenow fragment of Escherichia coli DNA polymerase I tends to run past the end of the template strand during DNA synthesis. We report here that certain non-hydrogen-bonding nucleoside analogues, when placed at the downstream 5'-end of a template DNA strand, cause the polymerases to stop more abruptly at the last coding nucleotide. This results in a considerably more homogeneous oligonucleotide being produced. Three novel nucleosides are tested as potential terminators: 4-methylindole beta-deoxynucleoside (M), 1-naphthyl alpha-deoxynucleoside (N) and 1-pyrenyl alpha-deoxynucleoside (P). Comparison is made to an abasic nucleoside (phi) and to unterminated synthesis. Of these, M is found to be the most efficient at terminating transcription, and both P and M are highly effective at terminating DNA synthesis. It is also found that the ability of a nucleoside to stall synthesis when it is internally placed in the template strand is not necessarily a good predictor of terminating ability at the end of a template. Such terminator nucleosides may be useful in the preparative enzymatic synthesis of RNA and DNA, rendering purification simpler and lowering the cost of synthesis by preventing the uptake of potentially costly nucleotides into unwanted products.

Actin filaments mediate DNA fiber formation in chronic inflammatory airway disease.

Purulent sputum from patients with chronic obstructive pulmonary disease has long been known to contain large DNA-rich fibers believed to impede airway drainage. We present a novel approach to study sputum structure using fluorescence microscopy to confirm the presence of large DNA-rich fibers and visualize for the first time filamentous actin in all sputum samples examined from patients with cystic fibrosis and chronic bronchitis. Both actin and DNA co-localize in the filaments previously identified as DNA alone. Treatment of sputum samples with recombinant human DNase I or the actin-filament-severing protein, gelsolin, both previously found to decrease viscosity, dissolves the sputum fiber bundles. Purified human DNA does not form large fibers alone in vitro but does so in the presence of filamentous actin, and these fiber bundles dissolve when treated with either gelsolin or DNase I. These findings implicate actin-DNA interactions in the pathogenesis of airway disease and identify both polymers as targets for therapy.

Fetal hemoglobin levels in sickle cell disease and normal individuals are partially controlled by an X-linked gene located at Xp22.2.

Fetal hemoglobin (Hb F) production in sickle cell (SS) disease and in normal individuals varies over a 20-fold range and is under genetic control. Previous studies suggested that variant Hb F levels might be controlled by genetic loci separate from the beta-globin complex on chromosome 11. Using microscopic radial immunodiffusion and flow cytometric immunofluorescent assays to determine the percentage of F reticulocytes and F cells in SS and nonanemic individuals, we observed that F-cell levels were significantly higher in nonanemic females than males (mean +/- SD, 3.8% +/- 3.2% v 2.7% +/- 2.3%). F-cell production as determined by F reticulocyte levels in SS females was also higher than in SS males (17% +/- 10% v 13% +/- 8%). We tested the hypothesis that F-cell production in both normal and anemic SS individuals was controlled by an X-linked locus with two alleles, high (H) and low (L). Using an algorithm to determine the 99.8% confidence interval of a normal distribution in nonanemic individuals, we estimated that males and females with at least one H allele had greater than 3.3% F cells. Comparisons of male-male or female-female SS sib pairs with discordant F reticulocyte levels distinguished two phenotypes in SS males (L, less than 12%; H, greater than 12%) and three phenotypes in SS females (LL, less than 12%; HL, 12% to 24%, HH greater than 24%). Linkage analysis using polymorphic restriction sites along the X chromosome in eight SS and one AA family localized the F-cell production (FCP) locus to Xp22.2, with a maximum lod score (logarithm of odds of linkage v independent assortment) of 4.6 at a recombination fraction of 0.04.

Frequency of congenital anomalies in patients with histiocytosis X.

The frequency of congenital anomalies in 39 cases of histiocytosis X collected over a 30 year period was 23%. Through a retrospective chart review of these cases and two control populations (children with bone tumors and children with suspected child abuse) we sought to assess the significance of this finding as well as any special characteristics of those histiocytic patients who had congenital anomalies. The frequency of congenital anomalies in the histiocytosis X group (23%) was greater than the frequency found in our control groups, the bone tumor group (13%), and the child advocacy control group (15%). Considering only major congenital anomalies, the histiocytic population had an increased frequency (18%) relative to both control groups (3% and 8%, respectively). Only one patient with unifocal eosinophilic granuloma had congenital anomalies. Patients with histiocytosis X and congenital anomalies were more likely to have histiocytosis X involving organ dysfunction (lung, liver, hematopoietic). Through this retrospective study we observe an increased frequency of congenital anomalies in patients with histiocytosis X. This observation does not seem to apply to patients with unifocal eosinophilic granuloma. The presence of congenital anomalies, especially multiple congenital anomalies, seemed to be a prognostic indicator of organ dysfunction in our histiocytic population.