rIL-10 enhances IL-10 signalling proteins in foetal alveolar type II cells exposed to hyperoxia.

Although the mechanisms by which hyperoxia promotes bronchopulmonary dysplasia are not fully defined, the inability to maintain optimal interleukin (IL)-10 levels in response to injury secondary to hyperoxia seems to play an important role. We previously defined that hyperoxia decreased IL-10 production and pre-treatment with recombinant IL-10 (rIL-10) protected these cells from injury. The objectives of these studies were to investigate the responses of IL-10 receptors (IL-10Rs) and IL-10 signalling proteins (IL-10SPs) in hyperoxic foetal alveolar type II cells (FATIICs) with and without rIL-10. FATIICs were isolated on embryonic day 19 and exposed to 65%-oxygen for 24 hrs. Cells in room air were used as controls. IL-10Rs protein and mRNA were analysed by ELISA and qRT-PCR, respectively. IL-10SPs were assessed by Western blot using phospho-specific antibodies. IL-10Rs protein and mRNA increased significantly in FATIICs during hyperoxia, but JAK1 and TYK2 phosphorylation showed the opposite pattern. To evaluate the impact of IL-8 (shown previously to be increased) and the role of IL-10Rs, IL-10SPs were reanalysed in IL-8-added normoxic cells and in the IL-10Rs' siRNA-treated hyperoxic cells. The IL-10Rs' siRNA-treated hyperoxic cells and IL-8-added normoxic cells showed the same pattern in IL10SPs with the hyproxic cells. And pre-treatment with rIL-10 prior to hyperoxia exposure increased phosphorylated IL-10SPs, compared to the rIL-10-untreated hyperoxic cells. These studies suggest that JAK1 and TYK2 were significantly suppressed during hyperoxia, where IL-8 may play a role, and rIL-10 may have an effect on reverting the suppressed JAK1 and TYK2 in FATIICs exposed to hyperoxia.

Comparison of Wright's formula and the Dunn method for measuring the umbilical arterial catheter insertion length.

BACKGROUND: Umbilical artery catheterization is the standard procedure for arterial access in neonatal intensive care units. An umbilical arterial catheter (UAC) needs to be placed accurately during the initial insertion because malpositioning increases catheter-related complications and subsequent repositioning exposes newborns to unnecessary handling, further radiologic exposure, and an increased risk of infection. To measure the UAC insertion length in newborns, we compared the conventional practice (i.e., the Dunn method) with a new formula: Wright's formula. METHODS: The study enrolled 119 newborns. A nomogram derived from Dunn was used during the first study period and the new formula devised by Wright (4 × birth weight + 7 cm) was used during the second study period. The catheter tip position on the initial radiograph was evaluated as correct (i.e., T6-T10), overinsertion (i.e., T10). RESULTS: The demographic profiles were not different between the two groups, which included sex; birth weight; and the number of preterm births, low-birth-weight (LBW) newborns, and very-low-birth-weight (VLBW) newborns. When using Wright's formula and the Dunn method, 83% of newborns and 61% of newborns, respectively, received a correct insertion (p < 0.05). The success rate for positioning the UAC tip between T7 and T8 was approximately two-fold higher when using Wright's formula than when using the Dunn method. In particular, the rate of correct insertion was significantly higher with Wright's formula in term newborns, LBW newborns, VLBW newborns, and small for gestational age (SGA) newborns (p < 0.05); however, the rate of overinsertion with the Dunn method was much higher in term newborns, LBW newborns, VLBW newborns, and SGA newborns (p < 0.05). CONCLUSION: The use of Wright's formula overall results in superior correct placement of the UAC tip. It may be a more accurate and practical method than the conventional practice for measuring the UAC insertion length in newborns.

Central venous cutdown in neonates: feasibility as a bedside procedure without general anesthesia.

BACKGROUND/PURPOSE: A silicone central venous catheter (CVC) is usually inserted using a percutaneous technique under general anesthesia. However, there are numerous reports on the postoperative adverse effects of general anesthesia in neonates. The aim of this study is to investigate the feasibility of open surgical cutdown (OSC) for central venous access without general anesthesia. METHODS: The medical records of patients who underwent OSC at bedside under sedation and local anesthesia were reviewed. Chloral hydrate (100mg/kg) was given orally for the induction of moderate to deep sedation 15 minutes before OSC; then the operative field was infiltrated with 1% lidocaine. When adequate sedation was not achieved, a bolus of phenobarbital (20mg/kg) was given intravenously. RESULTS: Thirteen Broviac lines were inserted into 12 patients. At insertion, the median gestational age was 29 weeks, birth weight was 1,140 g and age was 33 days. No patients required invasive ventilator care; 7 patients received nasal non-invasive ventilator care. Neither intubation nor inotropics were required during the intra- or postoperative period and no perioperative surgical complications occurred. The median catheter duration was 19.5 days. CONCLUSION: OSC at bedside for CVC insertion, using adequate sedation and local anesthesia, is a feasible procedure in neonates.

Interleukin-10 down-regulates cathepsin B expression in fetal rat alveolar type II cells exposed to hyperoxia.

PURPOSE: Hyperoxia has the chief biological effect of cell death. We have previously reported that cathepsin B (CB) is related to fetal alveolar type II cell (FATIIC) death and pretreatment of recombinant IL-10 (rIL-10) attenuates type II cell death during 65%-hyperoixa. In this study, we investigated what kinds of changes of CB expression are induced in FATIICs at different concentrations of hyperoxia (65%- and 85%-hyperoxia) and whether pretreatment with rIL-10 reduces the expression of CB in FATIICs during hyperoxia. MATERIALS AND METHODS: Isolated embryonic day 19 fetal rat alveolar type II cells were cultured and exposed to 65%- and 85%-hyperoxia for 12 h and 24 h. Cells in room air were used as controls. Cytotoxicity was assessed by lactate dehydrogenase (LDH) released into the supernatant. Expression of CB was analyzed by fluorescence-based assay upon cell lysis and western blotting, and LDH-release was re-analyzed after preincubation of cathepsin B-inhibitor (CBI). IL-10 production was analyzed by ELISA, and LDH-release was re-assessed after preincubation with rIL-10 and CB expression was re-analyzed by western blotting and real-time PCR. RESULTS: LDH-release and CB expression in FATIICs were enhanced significantly in an oxygen-concentration-dependent manner during hyperoxia, whereas caspase-3 was not activated. Preincubation of FATIICs with CBI significantly reduced LDH-release during hyperoxia. IL-10-release decreased in an oxygen-concentration-dependent fashion, and preincubation of the cells with rIL-10 significantly reduced cellular necrosis and expression of CB in FATIICs which were exposed to 65%- and 85%-hyperoxia. CONCLUSION: Our study suggests that CB is enhanced in an oxygen- concentration-dependent manner, and IL-10 has an inhibitory effect on CB expression in FATIICs during hyperoxia.

Transient carnitine transport defect with cholestatic jaundice: report of one case in a premature baby.

Carnitine (ß-hydroxy-γ-trimethylaminobutyric acid) is involved in the transport of long-chain fatty acids into the mitochondrial matrix and the removal of potentially toxic acylcarnitine esters. Transient carnitine transport defect is a rare condition in newborns reported in 1/90,000 live births. In this paper, we describe a case of transient carnitine transport defect found in a premature baby who had prolonged cholestatic jaundice and poor weight gain, and who responded dramatically to oral carnitine supplementation.

Comparison of the accuracy of neutrophil CD64 and C-reactive protein as a single test for the early detection of neonatal sepsis.

PURPOSE: Early identification of neonatal sepsis is a global issue because of limitations in diagnostic procedures. The objective of this study was to compare the diagnostic accuracy of neutrophil CD64 and C-reactive protein (CRP) as a single test for the early detection of neonatal sepsis. METHODS: A prospective study enrolled newborns with documented sepsis (n=11), clinical sepsis (n=12) and control newborns (n=14). CRP, neutrophil CD64, complete blood counts and blood culture were taken at the time of the suspected sepsis for the documented or clinical group and at the time of venipuncture for laboratory tests in control newborns. Neutrophil CD64 was analyzed by flow cytometry. RESULTS: CD64 was significantly elevated in the groups with documented or clinical sepsis, whereas CRP was not significantly increased compared with controls. For documented sepsis, CD64 and CRP had a sensitivity of 91% and 9%, a specificity of 83% and 83%, a positive predictive value of 83% and 33% and a negative predictive value of 91% and 50%, respectively, with a cutoff value of 3.0 mg/dL for CD64 and 1.0 mg/dL for CRP. The area under the receiver-operating characteristic curves for CD64 index and CRP were 0.955 and 0.527 (P<0.01), respectively. CONCLUSION: These preliminary data show that diagnostic accuracy of CD64 is superior to CRP when measured at the time of suspected sepsis, which implies that CD64 is a more reliable marker for the early identification of neonatal sepsis as a single determination compared with CRP.

Effect of recombinant IL-10 on cultured fetal rat alveolar type II cells exposed to 65%-hyperoxia.

BACKGROUND: Hyperoxia plays an important role in the genesis of lung injury in preterm infants. Although alveolar type II cells are the main target of hyperoxic lung injury, the exact mechanisms whereby hyperoxia on fetal alveolar type II cells contributes to the genesis of lung injury are not fully defined, and there have been no specific measures for protection of fetal alveolar type II cells. OBJECTIVE: The aim of this study was to investigate (a) cell death response and inflammatory response in fetal alveolar type II cells in the transitional period from canalicular to saccular stages during 65%-hyperoxia and (b) whether the injurious stimulus is promoted by creating an imbalance between pro- and anti-inflammatory cytokines and (c) whether treatment with an anti-inflammatory cytokine may be effective for protection of fetal alveolar type II cells from injury secondary to 65%-hyperoxia. METHODS: Fetal alveolar type II cells were isolated on embryonic day 19 and exposed to 65%-oxygen for 24 h and 36 h. Cells in room air were used as controls. Cellular necrosis was assessed by lactate dehydrogenase-release and flow cytometry, and apoptosis was analyzed by TUNEL assay and flow cytometry, and cell proliferation was studied by BrdU incorporation. Release of cytokines including VEGF was analyzed by ELISA, and their gene expressions were investigated by qRT-PCR. RESULTS: 65%-hyperoxia increased cellular necrosis, whereas it decreased cell proliferation in a time-dependent manner compared to controls. 65%-hyperoxia stimulated IL-8-release in a time-dependent fashion, whereas the anti-inflammatory cytokine, IL-10, showed an opposite response. 65%-hyperoxia induced a significant decrease of VEGF-release compared to controls, and similar findings were observed on IL-8/IL-10/VEGF genes expression. Preincubation of recombinant IL-10 prior to 65%-hyperoxia decreased cellular necrosis and IL-8-release, and increased VEGF-release and cell proliferation significantly compared to hyperoxic cells without IL-10. CONCLUSIONS: The present study provides an experimental evidence that IL-10 may play a potential role in protection of fetal alveolar type II cells from injury induced by 65%-hyperoxia.

Cathepsin B is activated as an executive protease in fetal rat alveolar type II cells exposed to hyperoxia.

Alveolar type II cells are main target of hyperoxia-induced lung injury. The authors investigated whether lysosomal protease, cathepsin B (CB), is activated in fetal alveolar type II cells in the transitional period from the canalicular to saccular stages during 65%-hyperoxia and whether CB is related to fetal alveolar type II cell (FATIIC) death secondary to hyperoxia. FATIICs were isolated from embryonic day 19 rats and exposed to 65%-oxygen for 24 h and 36 h. The cells exposed to room air were used as controls. Cell cytotoxicity was assessed by lactate dehydrogenase-release and flow cytometry, and apoptosis was analyzed by TUNEL assay and flow cytometry. CB activity was assessed by colorimetric assay, qRT-PCR and western blots. 65%-hyperoxia induced FATIIC death via necrosis and apoptosis. Interestingly, caspase-3 activities were not enhanced in FATIICs during 65%-hyperoxia, whereas CB activities were greatly increased during 65%-hyperoxia in a time-dependent manner, and similar findings were observed with qRT-PCR and western blots. In addition, the preincubation of CB inhibitor prior to 65%-hyperoxia reduced FATIIC death significantly. Our studies suggest that CB activation secondary to hyperoxia might have a relevant role in executing the cell death program in FATIICs during the acute stage of 65%-hyperoxia.

Molecular characterization of rotavirus diarrhea among children in South Korea: detection of an unusual G11 strain.

Among 312 rotavirus-positive samples collected from eight hospitals across South Korea during 2008 and 2009, the most prevalent circulating G genotype was G1 (35.9%), followed by G3 (24.7%), G2 (17.0%), G4 (7.7%), and G9 (2.6%). Notably, one unusual G11 lineage III strain-the first hypoendemic infection case in the world-was found. Of the P genotypes, P[8] (43.9%) was the most common, followed by P[6] (29.5%), P[4] (9.3%) and P[9] (0.6%). Determining G- and P-type combinations showed that G1P[8] was the most prevalent (20.5%), followed by G2P[6] (12.8%) and G3P[8] (12.8%). These findings provide new information concerning the current prevalence and spread of the rare G11 rotavirus.

Mechanical stretch promotes fetal type II epithelial cell differentiation via shedding of HB-EGF and TGF-alpha.

The mechanisms by which mechanical forces promote fetal lung development are not fully understood. Here, we investigated differentiation of fetal type II epithelial cells via the epidermal growth factor receptor (EGFR) in response to mechanical strain. First, we showed that incubation of embryonic day (E) 19 fetal type II cells with recombinant heparin-binding EGF-like growth factor (HB-EGF) or transforming growth factor (TGF)-alpha, but not with amphiregulin (AR), betacellulin (BTC) or epiregulin (EPR), increased fetal type II cell differentiation, as measured by surfactant protein B/C mRNA and protein levels. Next, we demonstrated that 5% cyclic stretch of E19 monolayers transfected with plasmid encoding alkaline phosphatase (AP)-tagged ligands shed mature HB-EGF and TGF-alpha into the supernatant and promoted type II cell differentiation. Release of these ligands was also observed in E19 cells subjected to higher degrees of cyclic strain, but not in cells exposed to continuous stretch. Interestingly, the addition of fibroblasts to type II cell cultures did not enhance release of HB-EGF. Whereas HB-EGF shedding was also detected in E18 cells exposed to 5% cyclic stretch, release of this ligand after 2.5% sustained stretch was restricted to cells isolated on E18 of gestation. In addition, mechanical stretch released EGF, AR and BTC. We conclude that mechanical stretch promotes fetal type II cell differentiation via ectodomain shedding of HB-EGF and TGF-alpha. The magnitude of shedding varied depending on gestational age, ligand, and strain protocol. These studies provide novel mechanistic information potentially relevant to fetal lung development and to mechanical ventilation-induced lung injury.

Roles of RhoA and Rac1 on actin remodeling and cell alignment and differentiation in fetal type II epithelial cells exposed to cyclic mechanical stretch.

Mechanical forces are critical for normal fetal lung development. However, the signaling events that promote lung maturation are not fully understood. In this study, the authors analyzed the role of Rho family guanidine triphosphatases (GTPases) in isolated embryonic day 19 (E19) fetal type II epithelial cells exposed to 5% cyclic stretch. The results showed that mechanical strain stimulated RhoA within 5 minutes of initiation of force. Rac1 was also activated, but not Cdc42. After 6 hours of equibiaxial stretch, actin filaments were oriented parallel to the long axis of the cells. By 16 hours, actin fibers still maintained the same orientation, but their intensity decreased when compared to 6 hours. These findings temporally correlated with a decrease in RhoA stimulation. Using adenoviruses encoding dominant negative mutants of RhoA and Rac1, the authors observed that both GTPases are important for strain-induced stress fiber formation, cell alignment, and extracellular signal-regulated kinase (ERK) phosphorylation. However, whereas inhibition of Rho increased surfactant protein C (SP-C) mRNA expression (a marker of type II cell differentiation), suppression of Rac had no effects. These studies suggest that RhoA and Rac1 regulate actin remodeling and cell alignment in fetal type II cells exposed to mechanical stretch. RhoA is a negative regulator of stretch-induced type II cell maturation.

Interleukin-10 protects cultured fetal rat type II epithelial cells from injury induced by mechanical stretch.

Mechanical ventilation plays a central role in the pathogenesis of bronchopulmonary dysplasia. However, the mechanisms by which excessive stretch of fetal or neonatal type II epithelial cells contributes to lung injury are not well defined. In these investigations, isolated embryonic day 19 fetal rat type II epithelial cells were cultured on substrates coated with fibronectin and exposed to 5% or 20% cyclic stretch to simulate mechanical forces during lung development or lung injury, respectively. Twenty percent stretch of fetal type II epithelial cells increased necrosis, apoptosis, and proliferation compared with control, unstretched samples. By ELISA and real-time PCR (qRT-PCR), 20% stretch increased secretion of IL-8 into the media and IL-8 gene expression and inhibited IL-10 release. Interestingly, administration of recombinant IL-10 before 20% stretch did not affect cell lysis but significantly reduced apoptosis and IL-8 release compared with stretched samples without IL-10. Collectively, our studies suggest that IL-10 may play an important role in protection of fetal type II epithelial cells from injury secondary to stretch.

Characteristics of Internet use in relation to game genre in Korean adolescents.

As the number of internet users increases, a new game genre using the internet as a networking tool is emerging. Some game genres are regarded as having greater addiction potentials than others. Games and the internet are closely related. We investigated games frequently used by adolescents and classified each of them with the help of game professionals. We also examined internet use patterns to identify relationships between game genre and internet use patterns. 627 middle school and high school students (male 488, female 139) completed questionnaires concerning computer and game use patterns and Korean internet addiction scales. Game genres were divided into eight criteria (simulation, role playing game, web board, community, action, adventure, shooting, and sports). Using Korean internet addiction scales, 627 participants were divided into a normal group (474), a potential risk group (128), and a high-risk group (25). Each group showed significant differences in total internet addiction scores. We classified players into specific game users based upon the game types they most prefer. Role playing game users showed significantly higher internet addiction scores than web board and sports game users. Game and internet addictions are also connected with interpersonal relationship patterns. We suggest that users of some game genre have unique psychological addiction potentials that are different from others and that this influences both game selection and internet use.

Amyoplasia congenita of the lower extremity: report in a premature baby.

Amyoplasia congenita is a diagnostic subgroup of children with arthrogryposis multiplex congenita (AMC). AMC is a relatively rare syndrome characterized by multiple joint contractures at birth. Amyoplasia congenita is the most common type of this syndrome with an occurrence rate of 1 in 10,000 live births, and mainly refers to the disorders with limb involvement. In this report, the author presents a premature baby with amyoplasia congenita, whose hips showed flexion, abduction, and external rotation contractures. The knees showed fixed extension contractures, so that his lower extremities were cylindrical with absent skin creases at birth.