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Pulmonary hypertension (PH) observed during respiratory syncytial virus (RSV) bronchiolitis is associated with morbidity and mortality, especially in children with congenital heart disease. Yet, the pathophysiological mechanisms of RSV-associated PH remain unclear. Therefore, this study aimed to investigate the pathophysiological mechanism of RSV-associated PH. We used a translational mouse model of RSV-associated PH, in which wild-type (WT) and suppression of tumorigenicity 2 (ST2) knockout neonatal mice were infected with RSV at 5 days old and reinfected 4 wk later. The development of PH in WT mice following RSV reinfection was evidenced by elevated right ventricle systolic pressure, shortened pulmonary artery acceleration time (PAT), and decreased PAT/ejection time (ET) ratio. It coincided with the augmentation of periostin and IL-13 expression and increased arginase bioactivity by both arginase 1 and 2 as well as induction of nitric oxide synthase (NOS) uncoupling. Absence of ST2 signaling prevented RSV-reinfected mice from developing PH by suppressing NOS uncoupling. In summary, ST2 signaling was involved in the development of RSV-associated PH. ST2 signaling inhibition may be a novel therapeutic target for RSV-associated PH. NEW & NOTEWORTHY We report that the pathogenic role of ST2-mediated type 2 immunity and mechanisms contribute to RSV-associated pulmonary hypertension. Inhibiting ST2 signaling may be a novel therapeutic target for this condition.

Extramedullary hematopoiesis (EMH) is the proliferation of hematopoietic stem cells outside the bone marrow and often observed in the liver, spleen in association with myeloproliferative disorders. On the other hand, EMH in the gastric wall is extremely rare. We report a rare case of EMH foci coexisting with early gastric cancer, which resulted in severe gastrointestinal bleeding. A 70-year-old male was diagnosed with myelofibrosis 4 years ago and visited our emergency room with a complaint of hematemesis and tarry stools. Upper gastrointestinal endoscopy revealed three early-stage gastric cancers in the lower gastric body and antrum, and biopsy was performed. Persistent bleeding at the biopsy site of the hypogastric lesion led to the consideration of surgical intervention. An open distal gastrectomy was performed. Postoperative histopathological examination revealed the tumor of the lower gastric body had EMH foci associated with myelofibrosis.

Tracheal intubation (TI) practice across pediatric emergency departments (EDs) has not been comprehensively reported. We aim to describe TI practice and outcomes in pediatric EDs in contrast to those in intensive are units (ICUs) and use the data to identify quality improvement targets.Consecutive TI encounters from pediatric EDs and ICUs in the National Emergency Airway Registry for Children (NEAR4KIDS) database from 2015 to 2018 were analyzed for patient, provider, and practice characteristics and outcomes: adverse TI-associated events (TIAEs), oxygen desaturation (SpOA total of 756 TIs in 13 pediatric EDs and 12,512 TIs in 51 pediatric/cardiac ICUs were reported. Median (interquartile range [IQR]) patient age for ED TIs was higher (32 [7-108] months) than that for ICU TIs (15 [3-91] months; p 0.001). Proportion of TIs for respiratory decompensation (52% of ED vs. 64% ICU), shock (26% vs. 14%), and neurologic deterioration (30% vs. 11%) also differed by location. Limited neck mobility was reported more often in the ED (16% vs. 6%). TIs in the ED were performed more often via video laryngoscopy (64% vs. 29%). Adverse TIAE rates (15.6% ED, 14% ICU; absolute difference = 1.6%, 95% confidence interval [CI] = -1.1 to 4.2; p = 0.23) and severe TIAE rates (5.4% ED, 5.8% ICU; absolute difference = -0.3%, 95% CI = -2.0 to 1.3; p = 0.68) were not different. Oxygen desaturation was less commonly reported in ED TIs (13.6%) than ICU TIs (17%, absolute difference = -3.4%, 95% CI = -5.9 to -0.8; p = 0.016). Among ED TIs, shock as an indication (adjusted odds ratio [aOR] = 2.15, 95% CI = 1.26 to 3.65) and limited mouth opening (aOR = 1.74, 95% CI = 1.04 to 2.93) were independently associated with TIAEs.While TI characteristics vary between pediatric EDs and ICUs, outcomes are similar. Shock and limited mouth opening were independently associated with adverse TI events in the ED.

Pulmonary hypertension (PH) has been observed in up to 75% of infants with moderate to severe respiratory syncytial virus (RSV) bronchiolitis and is associated with significant morbidity and mortality in infants with congenital heart disease. The purpose of the present study was to establish a mouse model of PH secondary to RSV bronchiolitis that mimics the disease etiology as it occurs in infants. Neonatal mice were infected with RSV at 5 days of age and then reinfected 4 wk later. Serum-free medium was administered to age-matched mice as a control. Echocardiography and right ventricular systolic pressure (RVSP) measurements via right jugular vein catheterization were conducted 5 and 6 days after the second infection, respectively. Peripheral capillary oxygen saturation monitoring did not indicate hypoxia at 2–4 days post-RSV infection, before reinfection, and at 2–7 days after reinfection. RSV-infected mice had significantly higher RVSP than control mice. Pulsed-wave Doppler recording of the pulmonary blood flow by echocardiogram demonstrated a significantly shortened pulmonary artery acceleration time and decreased pulmonary artery acceleration time-to-ejection time ratio in RSV-infected mice. Morphometry showed that RSV-infected mice exhibited a significantly higher pulmonary artery medial wall thickness and had an increased number of muscularized pulmonary arteries compared with control mice. These findings, confirmed by RVSP measurements, demonstrate the development of PH in the lungs of mice infected with RSV as neonates. This animal model can be used to study the pathogenesis of PH secondary to RSV bronchiolitis and to assess the effect of treatment interventions. NEW & NOTEWORTHY This is the first mouse model of respiratory syncytial virus-induced pulmonary hypertension, to our knowledge. This model will allow us to decipher molecular mechanisms responsible for the pathogenesis of pulmonary hypertension secondary to respiratory syncytial virus bronchiolitis with the use of knockout and/or transgenic animals and to monitor therapeutic effects with echocardiography.

BACKGROUND Transpyloric feeding tubes (TPT) are often recommended in critically ill children. Blind tube placement, however, can be difficult, be time-consuming, and incur multiple radiation exposures. An electromagnetic device (EMD) is available for confirmation of successful placement of TPTs. We conducted a retrospective cohort study to evaluate the efficacy of an EMD for TPT placement in children and determine its impact on placement success, radiation exposure, confirmation time, and cost for tube placement compared with traditional blind TPT placement. MATERIALS AND METHODS Retrospective data were collected in patients receiving a TPT before (pre-EMD group) and after implementation of an EMD (EMD group). RESULTS Need for radiographic exposure decreased significantly in the EMD group (n = 40) compared with the pre-EMD group (n = 38) (0.6 vs 1.6 x-rays, P < .001). TPTs were placed and confirmed without abdominal x-ray in 21 of 40 patients in the EMD group. There were no serious adverse events such as misplacement into the lung or pneumothorax or perforation injury of the stomach. Successful tube confirmation took a significantly shorter time in the EMD group than in the pre-EMD group (1.45 vs 4.59 hours, P < .0001). There was an estimated cost savings of $245.10 per placement associated with decreased x-ray and fluoroscopy. CONCLUSION The use of an EMD in children significantly decreased radiation exposure and confirmation time while maintaining TPT placement success. The use of an EMD can potentially offer large cost savings. Elimination of abdominal x-ray with EMD during TPT placement was achieved without any serious complications in approximately half of the children.

Background:Respiratory syncytial virus infection is the most frequent cause of acute lower respiratory tract disease in infants. A few reports have suggested that pulmonary hypertension is associated with increased severity of respiratory syncytial virus infection. We sought to determine the association between the pulmonary hypertension detected by echocardiography during respiratory syncytial virus bronchiolitis and clinical outcomes.Methods:We retrospectively reviewed 154 children admitted with respiratory syncytial virus bronchiolitis who had an echocardiography performed during the admission. The association between pulmonary hypertension and clinical outcomes including mortality, intensive care unit (ICU) admission, prolonged ICU stay (>10 days), tracheal intubation, and need of high frequency oscillator ventilation was evaluated.Results:Echocardiography detected pulmonary hypertension in 29 patients (18.7%). Pulmonary hypertension was observed more frequently in patients with congenital heart disease (CHD) (n = 11/33, 33%), chronic lung disease of infancy (n = 12/25, 48%), prematurity (Conclusions:Pulmonary hypertension detected by echocardiography during respiratory syncytial virus infection was associated with increased morbidity and mortality. Chronic lung disease was associated with pulmonary hypertension detected during respiratory syncytial virus bronchiolitis. Routine echocardiography is not warranted for previously healthy, haemodynamically stable patients with respiratory syncytial virus bronchiolitis.

A case of bilateral spontaneous chylothorax with respiratory syncytial virus (RSV) bronchiolitis has never been reported. We report the case of a 7-month-old boy born at 33 weeks gestation with a history of Down syndrome, atrial septal defect, pulmonary hypertension, and chronic lung disease, hospitalized due to RSV bronchiolitis who developed bilateral spontaneous chylothorax with exacerbation of pulmonary hypertension (PH). The patient died after 9 weeks of mechanical ventilation and treatment for PH. The autopsy showed acute infectious signs, a chronic interstitial lung disease with pulmonary hypertensive changes and subpleural cysts with no evidence of congenital lymphangiectasia. The cause of chylothorax in this child could be multifactorial. However, worsening pulmonary hypertension with RSV infection might have partially contributed to the development of chylothorax through elevated superior venous cava pressure. Thoracentesis should be considered for patients with Down syndrome and PH associated with congenital heart disease who develop persistent pleural effusion during RSV bronchiolitis to rule out chylothorax.

The hemodynamic effects of a patent ductus arteriosus (PDA) are well known including systemic hypoperfusion and volume overload on the left ventricle. This article aims to provide a review of the long-standing effect of a hemodynamically significant PDA on the pulmonary vasculature and the role of cardiac catheterization in preterm infants with a PDA and pulmonary hypertension.

Contains fulltext : 200437.pdf (Publisher’s version ) (Closed access) OBJECTIVES: The impact of nutrition status on outcomes in pediatric severe sepsis is unclear. We studied the association of nutrition status (expressed as body mass index z score) with outcomes in pediatric severe sepsis. DESIGN: Secondary analysis of the Sepsis Prevalence, Outcomes, and Therapies study. Patient characteristics, ICU interventions, and outcomes were compared across nutrition status categories (expressed as age- and sex-adjusted body mass index z scores using World Health Organization standards). Multivariable regression models were developed to determine adjusted differences in all-cause ICU mortality and ICU length of stay by nutrition status. SETTING: One-hundred twenty-eight PICUs across 26 countries. PATIENTS: Children less than 18 years with severe sepsis enrolled in the Sepsis Prevalence, Outcomes, and Therapies study (n = 567). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Nutrition status data were available for 417 patients. Severe undernutrition was seen in Europe (25%), Asia (20%), South Africa (17%), and South America (10%), with severe overnutrition seen in Australia/New Zealand (17%) and North America (14%). Severe undernutrition was independently associated with all-cause ICU mortality (adjusted odds ratio, 3.0; 95% CI, 1.2-7.7; p = 0.02), whereas severe overnutrition in survivors was independently associated with longer ICU length of stay (1.6 d; p = 0.01). CONCLUSIONS: There is considerable variation in nutrition status for children with severe sepsis treated across this selected network of PICUs from different geographic regions. Severe undernutrition was independently associated with higher all-cause ICU mortality in children with severe sepsis. Severe overnutrition was independently associated with greater ICU length of stay in childhood survivors of severe sepsis.

Low-dose methylprednisolone therapy in adults with early acute respiratory distress syndrome reduces systemic inflammation, duration of mechanical ventilation, and ICU length of stay. We report a pilot randomized trial of glucocorticoid treatment in early pediatric acute respiratory distress syndrome.Double-blind, placebo-controlled randomized clinical trial.Le Bonheur Children's Hospital, Memphis, TN.Children (0-18 yr) with acute respiratory distress syndrome undergoing mechanical ventilation.Patients were randomly assigned to steroid or placebo groups within 72 hours of intubation. IV methylprednisolone administered as loading dose (2 mg/kg) and continuous infusions (1 mg/kg/d) on days 1-7 and then tapered over days 8-14. Both groups were ventilated according to the Acute Respiratory Distress Syndrome Network protocol modified for children. Daily surveillance was performed for adverse effects.Thirty-five patients were randomized to the steroid (n = 17, no death) and placebo groups (n = 18, two deaths). No differences occurred in length of mechanical ventilation, ICU stay, hospital stay, or mortality between the two groups. At baseline, higher plateau pressures (p = 0.006) and lower Pediatric Logistic Organ Dysfunction scores (p = 0.04) occurred in the steroid group; other characteristics were similar. Despite higher plateau pressures on days 1 (p = 0.006) and 2 (p = 0.025) due to poorer lung compliance in the steroid group, they had lower PaCO2 values on days 2 (p = 0.009) and 3 (p = 0.014), higher pH values on day 2 (p = 0.018), and higher PaO2/FIO2 ratios on days 8 (p = 0.047) and 9 (p = 0.002) compared with the placebo group. Fewer patients in the steroid group required treatment for postextubation stridor (p = 0.04) or supplemental oxygen at ICU transfer (p = 0.012). Steroid therapy was not associated with detectable adverse effects.This study demonstrates the feasibility of administering low-dose glucocorticoid therapy and measuring clinically relevant outcomes in pediatric acute respiratory distress syndrome. Changes in oxygenation and/or ventilation are consistent with early acute respiratory distress syndrome pathophysiology and results of similar clinical trials in adults. We propose and design a larger randomized trial to define the role of glucocorticoid therapy in pediatric acute respiratory distress syndrome.

In this paper, we propose a novel radio access technology (RAT) selection method that can maximize total throughput by simultaneously selecting optimal RATs for a group of user equipments (UEs). To perform simultaneous selection, we also propose a novel throughput estimation method based on not wireless information collected from the existing network equipment but the accurate estimation of the amount of radio resources available for the UEs. Throughputs of all the UEs are estimated for all RAT selection patterns, by using the estimated available radio resources. The RAT selection method then selects a RAT selection pattern that gives the maximum total throughput. We conduct both simulations with a network simulator and field experiments with a commercially operating LTE network. The field experiments confirm that the proposed throughput estimation method can achieve an average estimation error of about 10%. The simulations confirm that the proposed method with a 10% throughput estimation error can achieve 96% throughput compared to that with perfect estimation. A conventional successive RAT selection method takes 1–10 minutes to achieve the same throughput as the proposed method, while the proposed simultaneous RAT selection method only takes about 1–10 seconds. Moreover, the conventional method achieves only 71% throughput of the proposed method with same processing time as the proposed method.

Increasing use of IEEE 802.11 WLAN specifications has resulted in dense deployment of access points (AP) to provide service to stations (STA). Dynamic sensitivity control (DSC) technology, which adjusts the carrier sense threshold (CST) to encourage more APs and STAs to transmit simultaneously, is considered an effective approach to improve the throughput in densely-deployed WLAN networks. The DSC algorithm should take into account both the increase of transmission opportunity, and the possible transmission rate degradation of related links caused by the consequent interference. Conventional algorithms, which set the CST value to allow simultaneous transmission only when a required signal to interference plus noise ratio (usually for a high transmission rate) can be guaranteed, are too conservative to improve the throughput. In this paper, we propose a novel DSC algorithm that enables simultaneous transmissions which lead to improved system throughput even when the transmission rate is degraded. Since whether system throughput can be improved by simultaneous transmission is different for each communication link, we set different CST values for different links instead of setting just one common CST value. We first formulate the throughput of each downlink as a function of related links' CST, and then search a set of CST values for these links to maximize the system throughput. A heuristic procedure is adopted in our algorithm to reduce calculation complexity. From numerical simulation results, it is shown that our algorithm can improve the system throughput by up to 30% when compared to a conventional algorithm.

Various radio access technology (RAT) selection methods between LTE and wireless LAN (WLAN) have been proposed, which aim to improve the capacity of the cellular network and to improve user satisfaction through mobile network operators. However, studies from the viewpoint of mobile virtual network operators (MVNOs) have not yet been investigated sufficiently. We propose a novel RAT virtualization system suitable for MVNO composed of a new network-initiated RAT selection method and RAT selection algorithms. The system conceals a change of IPs associated with a change of RATs and offers a context-aware virtualized RAT for the application server and user application. We demonstrate a new RAT selection method by developing a prototype of the proposed RAT selection system. We also evaluate a system-level performance by using a network simulator (NS-3) and show that our proposed algorithm outperforms conventional algorithms in terms of the WLAN usage ratio and user satisfaction.

The size of data chunk diverges from 101 to 1010 bits. Generally, if a network carries in a way both of big size data and small size data, the performance is extremely degraded by the big size data. Then, we propose to select a wireless cell among of multiple cells by referring context information such as data size and user's situation such as moving velocity. Especially, we show the improvement on connection level performance by dynamically selecting a cell based on the above context information. Further, we compare the packet level performance for single cell and multiple cells, and summarize the advantage of multiple cells environment with context aware cell selection.

With increase in the use of Wireless LANs in the enterprise area, network systems are often scattered across multiple locations in a wide area. Hence, there may be cases where a network administrator manages multiple locations. When users complain about connectivity issues, network administrators are expected to diagnose these problems without disrupting the normal operation of devices such as wireless stations (STAs) or access points (APs). In such cases, an on-site failure diagnosis is both time-consuming and expensive. Thus, an automated diagnostic technique to identify the cause of failure is important. We propose a method that can automatically identify the cause of the connectivity issues. The proposed method does not introduce any additional monitoring device, or require any functionality to be added in the AP or STA. In our proposed method, we send test packets to all STAs periodically and analyze the distribution of the responses and the RSSIs (received signal strength indicators) of the STAs. This helps to distinguish whether the connectivity issue is being caused by an AP failure, STA failure, or by a coverage-hole, which is a lack of network connectivity in certain areas of a building. The experimental results show that our proposed method is effective for the detection of AP failures, STA failures, and coverage-hole failures. From the detection results of a long experimental trial conducted in an actual office environment, it was observed that the false-detection probability of AP failure was very low. The STA failure was reported to be 0.36%, which was assumed to be because of hardware switch-offs or false detections because STA breakdowns were not reported during the trial. The ratio of the status “AP failure or STA failure” in the total failure detection was about 11%. Therefore, our proposed diagnosis system can suggest the cause of failure with a probability of 89%.

Neonatal arterial switch operation for simple dextro-transposition of the great arteries (d-TGA) has almost eliminated the occurrence of pulmonary vascular obstructive disease compared to patients who underwent Mustard or Senning procedure at an older age. We report a case of a neonate with d-TGA and intact ventricular septum who underwent arterial switch operation and yet developed severe pulmonary vascular obstructive disease within two months.

© 2015 Elsevier Ltd. Objective: A double-blind, randomized controlled trial showed that low-dose glucocorticoid therapy in pediatric ARDS patients is feasible and may improve both ventilation and oxygenation indices in these patients. However, the molecular mechanisms underlying potential changes in outcomes remain unclear. Based on these clinical findings, this study was designed to examine the effects of intravenous methylprednisolone on circulating inflammatory biomarkers in pediatric ARDS patients. Design: Double-blind, placebo-controlled randomized trial with blood collection on study entry and day 7. Setting: Tertiary care children's hospital. Patients: Children (0-18. years) with ARDS undergoing mechanical ventilation. Interventions: 35 children were randomized within 72. h of mechanical ventilation. The glucocorticoid group received methylprednisolone 2. mg/kg loading dose followed by 1. mg/kg/day continuous infusion from days 1 to 7. Both groups were ventilated following the ARDSnet recommendations. WBC and differential cell counts, plasma cytokines and CRP levels, and coagulation parameters were analyzed on days 0 and 7. Results: At study entry, the placebo group had higher IL-15 and basophil levels. On day 7, in comparison to study entry, the placebo group had lower IL-1α, IFN-γ and IL-10 levels. The glucocorticoid group had lower INF-α, IL-6, IL-10, MCP-1, G-CSF and GM-CSF levels, and higher IL-17α levels on day 7 in comparison to study entry. Total and differential cell counts remained unchanged within the placebo group between days 0 and 7, whereas in the glucocorticoid group total WBC and platelets counts were increased on day 7. Pearson's correlation studies within the placebo and glucocorticoid groups revealed positive and negative correlations between cytokine levels, cell counts, coagulation parameters and relevant clinical parameters of disease severity identified in our previous study. Multiple regression models identified several cytokines as predictors for alterations in clinical parameters of disease severity. Conclusion: This pilot study shows the feasibility of simultaneously measuring multiple inflammatory cytokines, cell counts and coagulation parameters in pediatric ARDS patients. We report statistical models that may be useful for future, larger trials to predict ARDS severity and outcomes.

Therapeutic hypercapnia (TH), an intentional inhalation of CO(2), has been shown to improve pulmonary function in certain models of lung injury. We tested the null hypothesis that TH does not improve hyperoxic lung injury in neonatal rats. The prospective, randomized study was set at Research laboratory in Children's Hospital. Forty-five newborn rats were randomly assigned to three groups (n = 15/group), and exposed to 96 h of normoxia (FiO(2) = 0.21), hyperoxia (FiO(2)0.98), and TH (FiO(2) = 0.95, FiCO(2) = 0.05). Lung histology, wet-weight to dry-weight ratio, and concentrations of pro- and anti-inflammatory cytokines (IL-1beta, IL-6, TNF-alpha, and IL-10) were used to evaluate pulmonary damage. Using a scale of 0-4, the total scores for lungs hypercellularity, inflammation, and hemorrhage was significantly increased from a median value of 1.5 in normoxia to 2.5 in hyperoxia (P0.05) and 3.0 with TH (P0.001, nonparametric ANOVA). The interstitial space relative to the alveolar space, as a measure of hypercellularity, was increased by 18% during hyperoxia and by 44% with TH compared with normoxia. TH significantly increased the size of the interstitial space by 22% compared with hyperoxia (P0.001). The lung wet-weight to dry-weight ratio was increased by 10% in both hyperoxic groups (P0.001). Both hyperoxic groups showed significant reductions in the concentration of IL-1beta compared with normoxia (P0.001), whereas the ratio of IL-1beta to IL-10 was significantly decreased, indicating an anti-inflammatory trend. TH does not prevent histological manifestations of hyperoxic lung injury in spontaneously breathing neonatal rats and may worsen the outcome.

We investigated the effects of (1,4)-alpha-D-glucan (alpha-DG), a novel immune stimulatory drug from Tinospora cordifolia, on the concentration of pro- and anti-inflammatory cytokines (interleukin [IL]-1beta, IL-6, tumour necrosis factor-alpha [TNF-alpha], gamma-interferon [IFN-gamma] and IL-10) in the lung and spleen of endotoxin-stimulated juvenile rats. Experimental groups (n = 16/group) included controls with an intraperitoneal injection of saline, endotoxaemic rats with a non-lethal dose of 10 mg/kg Escherichia coli endotoxin, and endotoxaemic rats treated with two doses of 10 mg/kg alpha-DG, intraperitoneally, 2 and 4 hr after endotoxin injection. At 24 hr of treatment, rats were euthanized and lungs and spleen were removed for cytokines determination and lung injury. Endotoxaemia increased IL-1beta concentration by fivefold in both organs, while creating a moderate pulmonary hypercellularity (demonstrated by about 11% increase in the alveolar-septal thickening and 11% decrease in the alveolar-interstitial space ratio). In the lung, alpha-DG treatment reduced concentrations of IL-1beta by 30% (p0.05), IL-6 by 43% (p0.01), IFN-gamma by 46% (p0.01) and the anti-inflammatory cytokine, IL-10, by 31% (p0.05) compared to endotoxaemia. In the spleen, alpha-DG treatment decreased the ratio of IL-1beta to IL-10 by 55% (p0.05), demonstrating an anti-inflammatory trend. These data suggest that alpha-DG differentially modulates cytokine response in the lung and spleen and modifies the pro- and anti-inflammatory balance during an early period of endotoxaemia in juvenile rats.

Intensive Care Med DOI 10.1007/s00134-015-4027-3 Andreas Schwingshackl Gianfranco Umberto Meduri Dai Kimura Stephania A. Cormier Kanwaljeet J. S. Anand Corticosteroids in pediatric ARDS: all cards on the table Accepted: 8 August 2015 O Springer-Verlag Berlin Heidelberg and ESICM 2015 Dear Editor, Hardly any topic in modern critical care medicine remains as controver- sial as steroid administration in acute respiratory distress syndrome (ARDS), despite multiple adult ran- domized controlled trials (RCTs) and recent pediatric data. The article by Yehya et al. [1] and the editorial commentary by Peters et al. [2] are vital, since few, if any, therapeutic approaches are simultaneously asso- ciated with such profound potential benefits and risks as steroid therapy in critically ill patients. Marked contradiction, however, exists between the Yehya et al. data and the findings of well-designed and protocol-driven RCTs in adult ARDS patients. These studies consistently reported significant improvements in markers of systemic inflammation, ventilator-free days, ICU-free days, no changes or actually improved survival, and either no increase or decreases in infection rate [3, 4]. The findings of Yehya et al. cannot be interpreted because the specific indi- cations for corticosteroid use were not reported. To imply that any type of steroid, at any concentration, and CO RRESPONDENCE used for more than 24 h represents a protocol-driven treatment for pedi- atric ARDS (PARDS) is simply not justifiable. Further, grouping short-term (less than 24 h) and non-corticosteroid exposed patients together is an improper control for evaluating ster- oid therapy. Corticosteroids can exert important, non-genomic effects within minutes, including decreased cell adhesion, phosphokinase activa- tion, MCP-1 and H 2 O 2 release, CD63 translocation, TNF-a and IL-6 expression. Possible corticosteroid effects cannot be assessed unless exposed and non-exposed patients are categorically separated. Thus, proposing that this single-center, observational study ‘‘has relevance for clinical practice’’, a conclusion unsupported by data, will likely mis- lead and confound many bedside physicians. Undoubtedly, the most likely explanation for Yehya et al.’s findings are (1) selection of steroid therapy for the sickest patients (con- founding by indication) and (2) rebound effects resulting from abrupt discontinuation of corticosteroids, as is well documented by worsening PaO 2 /FiO 2 ratios and increasing CRP levels. Owing to the wide-ranging impli- cations and inherent responsibility of publishing patient data, it is impera- tive that we treat this topic with the utmost equipoise until clear evidence for or against steroid use in ARDS/ PARDS is gained. Whether compar- ative effectiveness research (CER) can provide such evidence is ques- tionable, since the US Food and Drug Administration, European Medicines Agency, or other labeling agencies do not consider this research methodol- ogy Level 1 evidence. CER studies can ‘‘adjust’’ the outcomes for measured confounders, and boot- strapping techniques like propensity scoring can reduce the margin of inferential errors, but only large, well- designed RCTs can control for unmeasured and non-measurable confounders. We recommend caution in drawing conclusions from a data set with multiple confounding vari- ables and improper controls. Statistical approaches such as propensity score matching can only take into account measured con- founding factors, whereas randomized trials allow for control- ling of both measured and unmeasured confounders. The bene- ficial or no-harm results reported in adult RCTs cannot be disregarded unless systematically investigated in pediatric patients. We recently pub- lished a feasibility RCT investigating prolonged low-dose methylpred- nisolone in pediatric ARDS [5] and, undoubtedly, there is an urgent need to conduct a large-scale, well-de- signed RCT in PARDS. References 1. Yehya N, Servaes S, Thomas NJ, Nadkarni VM, Srinivasan V (2015) Corticosteroid exposure in pediatric acute respiratory distress syndrome. Intensive Care Med. doi: 10.1007/s00134-015-3953-4 2. Peters MJ, Ray S, Kneyber M (2015) Corticosteroids for paediatric ARDS: unjustified—even unjustifiable? Intensive Care Med. doi: 10.1007/s00134-015-3963-2 3. Confalonieri M, Urbino R, Potena A, Piattella M, Parigi P, Puccio G, Della Porta R, Giorgio C, Blasi F, Umberger R, Meduri GU (2005) Hydrocortisone infusion for severe community-acquired pneumonia: a preliminary randomized study. Am J Respir Crit Care Med

Diffuse alveolar hemorrhage (DAH) from systemic lupus erythematosus (SLE) is a rare but potentially life-threatening condition. We report the case of a 14-year-old female with SLE who developed hypoxia and shock secondary to severe alveolar hemorrhage. She was successfully managed by placement on extracorporeal membrane oxygenation (ECMO) followed by emergent pulmonary lobectomy and medical treatment including high-dose methylprednisolone, cyclophosphamide, intravenous immunoglobulin, and plasmapheresis.

Fifth generation mobile communications (5G) are expected to accommodate rapidly increasing mobile traffic aiming at the realization of a “Hyper Connected World” in which all people and surrounding things are connected and information is exchanged between them, and to play the role of a basis of the Internet of everything. A lot of research projects have started focusing on the research of 5G since around 2013, and some agreements are being formed about the vision and the candidate technologies of 5G. The 5G wireless network is expected to become a “Heterogeneous Network” where new wireless access technologies incompatible with 4G and the wireless access technologies for unlicensed band are incorporated with the enhanced technology of 4G (e.g. IMT-advanced). This paper introduces the vision and technology trends of 5G, shows key directions of the research and development of 5G in the future, and introduces some of our studies on 5G.

Generation of carbon, silicon, and silver clusters by a laser- vaporization supersonic expansion cluster beam source was studied using a reflectron-type time-of-flight (TOF) mass spectrometer. The atomic cluster was generated by the laser vaporization of a solid sample disk, followed by cooling with supersonic expansion of pulsed helium gas. The neutral cluster, carried by helium gas, was ionized by a fourth harmonic Nd:YAG laser and accelerated by high voltage to the reflectron mass spectrometer. Positi ve-ion TOF mass spectra of carbon, silicon, and silver clusters were compared for se veral cluster source nozzle conditions. Helium gas pressure at the time of vaporization of solid material played the key role in cluster size range obtained. The effect of pressure was thoroughly examined for a relatively large carbon cluster, which was regarded as fullerene.

An autonomous downlink interference control method for closed subscriber group (CSG) Long Term Evolution (LTE) femtocells is proposed. The proposed method integrates three interference control methods - power control, timing synchronization, and resource partitioning - by leveraging measurement results in various environments. The interferences on physical downlink data channel (PDSCH) and physical downlink control channel (PDCCH) are separated by using the timing synchronization between macrocells and femtocells, and these two interferences are handled independently. The interference on PDCCH is controlled by the transmission power control and that on PDSCH is controlled by the frequency resource partitioning. Moreover, it can deal with both inter-tier and intra-tier interference on the PDSCH and PDCCH. Computer simulations in accordance with 3GPP specifications are conducted in order to evaluate the effect of the proposed method compared with an existing transmission power control method. The results of the simulations show that the proposed method reduced PDCCH outage probability for both macro users and femto users. They also show that the proposed method can reduce downlink femtocell interference for macro users (victim UEs) without reducing femtocell throughput.