Won Soon Park

In vitro and in vivo efficacy of new blue light emitting diode phototherapy compared to conventional halogen quartz phototherapy for neonatal jaundice.

High intensity light emitting diodes (LEDs) are being studied as possible light sources for the phototherapy of neonatal jaundice, as they can emit high intensity light of narrow wavelength band in the blue region of the visible light spectrum corresponding to the spectrum of maximal bilirubin absorption. We developed a prototype blue gallium nitride LED phototherapy unit with high intensity, and compared its efficacy to commercially used halogen quartz phototherapy device by measuring both in vitro and in vivo bilirubin photodegradation. The prototype device with two focused arrays, each with 500 blue LEDs, generated greater irradiance than the conventional device tested. The LED device showed a significantly higher efficacy of bilirubin photodegradation than the conventional phototherapy in both in vitro experiment using microhematocrit tubes (44±7% vs. 35±2%) and in vivo experiment using Gunn rats (30±9% vs. 16±8%). We conclude that high intensity blue LED device was much more effective than conventional phototherapy of both in vitro and in vivo bilirubin photodegradation. Further studies will be necessary to prove its clinical efficacy.

PHOX2B mutations in patients with Ondine–Hirschsprung disease and a review of the literature

Congenital central hypoventilation syndrome (CCHS), also known as Ondines curse, is characterized by idiopathic failure of autonomic breathing and is often associated with neurocristopathies such as Hirschsprung disease (HSCR). CCHS is caused by mutations in the paired-like homeobox 2B (PHOX2B) gene, often manifest as polyalanine repeat expansions. Herein, we report the cases of two unrelated Korean patients with Ondine–Hirschsprung disease. The patients clinical manifestations were apnea and cyanosis requiring immediate endotracheal intubation, recurrent hypoventilation with hypercapnia, hypoxia after ventilator removal, and abdominal distension since birth. Intestinal biopsies were performed and the absence of ganglion cells in the colon was consistent with HSCR. We performed direct sequencing analysis in the PHOX2B and RET genes and fluorescence polymerase chain reaction in order to determine the polyalanine tract expansion in exon 3 of the PHOX2B gene. Expansion mutations were detected in both patients; one had 20/24 repeats and the other had 20/27 repeats. The 20/24 genotype has not been previously described in severe CCHS phenotypes and associated HSCR. We believe that the information in this report will improve our understanding of the phenotypic and genotypic heterogeneities of CCHS and HSCR.

Comparison of Clinical Efficacy of Newfactan® versus Surfacten® for the Treatment of Respiratory Distress Syndrome in the Newborn Infants

Newfactan® is a domestically developed, bovine lung-derived, semi-synthetic surfactant. The aim of this study was to compare the clinical efficacy of Newfactan® with that of Surfacten® in the treatment of respiratory distress syndrome (RDS). Newfactan® or Surfacten® was randomly allocated to 492 newborn infants who were diagnosed as RDS and required surfactant instillation in four participating hospitals. The comparisons were made individually in two subsets of infants by birth weight (<1,500 g group [n=253] and ≥1,500 g group [n=239]). Short-term responses to surfactant and acute complications, such as the total doses of surfactant instilled, response type, extubation rate, ventilator settings, changes in respiratory parameters, air leak, patent ductus arteriosus, pulmonary hemorrhage, and intraventricular hemorrhage, and mortality during the 96 hr after surfactant instillation were measured. Long-term outcome and complications, such as total duration of intubation, bronchopulmonary dysplasia and periventricular leukomalacia, and ultimate mortality were measured. There were no significant differences in demographic and perinatal variables, short-term responses to surfactant and acute complications, and long-term outcome and complications between Newfactan® and Surfacten® in both birth weight groups. We concluded that Newfactan® was comparable to Surfacten® in the clinical efficacy in the treatment of RDS in both birth weight groups.

Nω-nitro-L-arginine methyl ester (L-NAME) attenuates the acute inflammatory responses and brain injury during the early phase of experimental Escherichia coli meningitis in the newborn piglet

Abstract We evaluated the anti-inflammatory and neuroprotective effect of nonselective NOS inhibitor, Nω-nitro-Larginine methyl ester (L-NAME), in experimental bacterial meningitis in the newborn piglet. Meningitis was induced by intracisternal injection of 108 colony forming units of Escherichia coli. L-NAME 10 mg kg-1 was given intravenously 30 min before induction of meningitis. L-NAME significantly attenuated the increase in intracranial pressure and decrease in cerebrospinal fluid glucose concentration observed in the meningitis group. Systemic and cerebral perfusion pressure were even higher compared to the control and meningitis groups. However, the meningitis-induced increase in tumor necrosis factor- α level, leukocyte numbers and lactate level in the cerebrospinal fluid was not significantly attenuated with L-NAME administration. Reduced cerebral cortical cell membrane Na+ ,K+-ATPase activity and increased lipid peroxidation products, indicative of meningitis-induced brain cell membrane dysfunction, were significantly improved with L-NAME treatment. Decreased brain glucose and ATP levels were also significantly improved with L-NAME treatment. These findings suggest that L-NAME was effective in attenuating the acute inflammatory responses and brain injury in neonatal bacterial meningitis. [Neurol Res 2001; 23: 862-868]