HCMV-induced signaling through gB-EGFR engagement is required for viral trafficking and nuclear translocation in primary human monocytes.

Previous analysis of postentry events revealed that human cytomegalovirus (HCMV) displays a unique, extended nuclear translocation pattern in monocytes. We determined that c-Src signaling through pentamer engagement of integrins is required upon HCMV entry to avoid sorting of the virus into late endosomes and subsequent degradation. To follow up on this previous study, we designed experiments to investigate how HCMV-induced signaling through the other major axis-the epidermal growth factor receptor (EGFR) kinase-regulates viral postentry events. Here we show that HCMV induces chronic and functional EGFR signaling that is distinct to the virus as compared to the natural EGFR ligand: EGF. This chronic EGFR kinase activity in infected monocytes is required for the proper subcellular localization of the viral particle during trafficking events, as well as for promoting translocation of viral DNA into the host nucleus. Our data indicate that HCMV glycoprotein B (gB) binds to EGFR at the monocyte surface, the virus and EGFR are internalized together, and gB remains bound to EGFR throughout viral postentry events until de-envelopment to promote the chronic EGFR kinase activity required for viral trafficking and nuclear translocation. These data highlight how initial EGFR signaling via viral binding is necessary for entry, but not sufficient to promote each viral trafficking event. HCMV appears to manipulate the EGFR kinase postentry, via gB-EGFR interaction, to be active at the critical points throughout the trafficking process that leads to nuclear translocation and productive infection of peripheral blood monocytes.

Performance of the BIG Score in Predicting Mortality in Normotensive Children With Trauma.

OBJECTIVES: Children have a larger reserve for traumatic hemorrhagic shock, requiring a score that uses physiologic variables other than hypotension. Recently, the BIG score comprising admission base deficit, international normalized ratio, and the Glasgow Coma Scale has been reported to predict traumatic mortality. We aimed to validate the performance of the BIG score in mortality prediction of normotensive children with trauma. METHODS: We reviewed 1046 injured children (<18 years) who visited a Korean academic hospital from 2010 to 2018, excluding those with age-adjusted hypotension. In-hospital mortality, the BIG score and its predicted mortality, Revised Trauma Score, and Pediatric Trauma Score were calculated. We compared areas under the curve (AUCs) for in-hospital mortality of the 3 scores and did in-hospital and BIG-predicted mortalities. RESULTS: Of the 1046 children, 554 were enrolled with a 4.9% in-hospital mortality rate. The median BIG score was higher in the nonsurvivors (6.4 [interquartile range, 4.4-9.2] vs 20.1 [16.5-24.8]; P < 0.001). The AUC of the BIG score was 0.94 (95% confidence interval [CI], 0.92-0.96), which was higher than that of Pediatric Trauma Score (0.87 [95% CI, 0.84-0.90]; P < 0.001). The AUC of the BIG score tended to be higher than that of Revised Trauma Score without statistical significance (0.90 [95% CI, 0.87-0.92]; P = 0.130). We noted a parallel between in-hospital and BIG-predicted mortalities. The hemorrhage-related nonsurvivors showed higher median base deficit and BIG score than did the isolated traumatic brain injury-related ones. CONCLUSIONS: The BIG score can predict mortality with excellent accuracy in normotensive children with trauma.

Initial Characteristics and Clinical Severity of Hemophagocytic Lymphohistiocytosis in Pediatric Patients Admitted in the Emergency Department.

OBJECTIVES: The diagnosis and management of children with hemophagocytic lymphohistiocytosis (HLH) admitted in the emergency department (ED) are challenging. The present study aimed at describing the initial characteristics of pediatric patients with HLH upon admission in the ED. Moreover, the clinical severity of the condition was assessed. METHODS: We performed a retrospective study of patients who visited the pediatric ED and were newly diagnosed with HLH during hospitalization between February 2012 and January 2017. The patients were classified in the clinically unstable group if at least 1 of the following conditions was observed upon admission in the ED: hypoxia requiring oxygen supplementation, hypotension requiring inotropic support, coagulopathy with prothrombin time (international normalized ratio, ≥1.5), and seizures or altered consciousness. RESULTS: We enrolled 31 pediatric patients with HLH, with a median age of 6.53 years (interquartile range, 1.35-13.24 years). Abdominal discomfort along with fever (74.2%) was the most common presenting symptom in patients admitted in the ED. Based on the HLH-2004 diagnostic criteria, fever (96.8%), hyperferritinemia (96.8%), splenomegaly (74.2%), hypertriglyceridemia and/or hypofibrinogenemia (67.7%), and bicytopenia (41.9%) were observed in the patients. However, only 8 patients (25.8%) met the criteria. Nineteen patients (61.3%) were included in the clinically unstable group. This group had lower albumin (2.3 vs 3.3 g/dL, P = 0.002) and fibrinogen levels and higher ferritin level and neutrophil count than the clinically stable group. Meanwhile, the number of clinical findings that met the diagnostic criteria was not different between the 2 groups. Lower albumin level was a significant risk factor in the clinically unstable group (odds ratio, 0.040; P = 0.004). CONCLUSIONS: Pediatric patients with HLH often have clinically unstable conditions upon admission in the ED. However, only few patients meet the HLH-2004 diagnostic criteria. Lower albumin level may be useful in assessing clinically unstable patients and preparing for possible deterioration.

Molecular and evolutionary analysis of dengue virus serotype 2 isolates from Korean travelers in 2015.

In Korea, dengue infection has been frequently reported in travelers to tropical and subtropical countries. Global warming increases the probability of autochthonous dengue outbreaks in Korea. In this report, the molecular and evolutionary properties of four dengue virus (DENV) type 2 isolates from Korean overseas travelers were examined. Three of these isolates were classified as Cosmopolitan genotypes and further divided into sublineages 1 (43,253, 43,254) and 2 (43,248), while the other isolate (KBPV-VR29) was related to American genotypes. The variable amino acid motifs related to virulence and replication were identified in the structural and non-structural proteins. A negative selection mechanism was clearly verified in all of the DENV proteins. Potential recombination events were identified in the NS5 protein of the XSBN10 strain. The substitution rate (5.32 × 10-4 substitutions per site) and the time of the most recent common ancestor (TMRCA) for each evolutionary group were determined by the Bayesian skyline coalescent method. This study shows that DENV type 2 strains with distinct phylogenetic, evolutionary, and virulence characteristics have been introduced into Korea by overseas travelers and have the potential to trigger autochthonous dengue outbreaks.

Delayed adenosine therapy is associated with the refractory supraventricular tachycardia in children.

OBJECTIVES: To study the association of time intervals on adenosine therapy with the occurrence of refractory supraventricular tachycardia (SVT) in children. METHODS: We reviewed 334 episodes of presumed SVT requiring adenosine in children (<18 years) who visited 4 academic hospital emergency departments (EDs) from July 2013 through June 2017. Refractory SVT was defined as an SVT episode persisting after 2 doses of adenosine. Clinical and electrocardiographic findings, and symptom-to-adenosine (symptom-to-ED plus ED-to-adenosine) time of refractory and responsive SVT episodes were compared. Multivariable logistic regression was performed to identify factors associated with the occurrence of refractory SVT. RESULTS: Of 211 SVT episodes, 42 episodes of refractory SVT (19.9%) were noted (overall sinus conversion rate, 79.6%). The refractory episodes were associated with a higher frequency of known structural heart diseases (9.5% vs. 1.8%; P = 0.030) and a longer median ED-to-adenosine time (15.5 vs. 11.0 min; P = 0.018). The association of the ED-to-adenosine time with refractory SVT remained significant after adjustment (for increment of 1 min; aOR, 1.02; 95% CI, 1.007-1.04). CONCLUSIONS: Delayed adenosine therapy is associated with the occurrence of refractory SVT in children, supporting the need for prompt adenosine therapy.

Point-of-care ultrasound may be useful for detecting pediatric intussusception at an early stage.

BACKGROUND: This study aimed to verify the usefulness of point-of-care ultrasound (POCUS) performed by pediatric emergency physicians for detecting intussusception at an early stage. METHODS: This retrospective study included 1-month- to 6-year-old children with clinically suspected intussusception, who underwent POCUS in the pediatric emergency department between December 2016 and February 2018. The criteria for performing POCUS were set to broader standards: presenting any one of intermittent abdominal pain/irritability or bloody stool, or ≥ 2 symptoms among nonspecific abdominal pain/irritability, abdominal mass/distension, vomiting, or lethargy. POCUS results were interpreted and categorized as "negative" or "suspicious," and a radiologist performed confirmatory ultrasound in "suspicious" cases. RESULTS: We analyzed 575 POCUS scans from 549 patients (mean age, 25.5 months). Among the 92 "suspicious" cases (16.0%), 70 (12.2%) were confirmed to have intussusception. POCUS showed 100% sensitivity, 95.6% specificity, and 97.8% accuracy. Patients with confirmed intussusception were mainly diagnosed in the early stages, with a mean symptom duration of 11.7 h, and most patients (97.1%) were treated successfully via air enema reduction. Compared to the non-intussusception group, the intussusception group had more intermittent abdominal pain (P < 0.001), but less vomiting (P = 0.001); the other clinical features showed no intergroup differences. CONCLUSION: POCUS performed using the criteria set to broader standards by pediatric emergency physicians may be useful for detecting intussusception at an early stage, which may present with obscure clinical symptoms.

Point-of-Care Ultrasound Could Streamline the Emergency Department Workflow of Clinically Nonspecific Intussusception.

OBJECTIVES: The aim of this study was to evaluate whether point-of-care ultrasound (POCUS) for intussusception screening streamlines the workflow of clinically nonspecific intussusception (CNI), an intussusception presenting with only 1 manifestation of the classic triad, and/or vomiting. METHODS: We reviewed 274 consecutive children with intussusception, aged 6 years or younger, who visited a tertiary care hospital emergency department between May 2012 and April 2016. This period was dichotomized by May 2014 (the "PRE" and "POST" groups), starting point of implementation of the POCUS protocol for intussusception screening. All children with CNI who had positive results on or forwent POCUS underwent radiologist-performed ultrasound (US). We measured and compared emergency department length of stay (EDLOS), the sum of door-to-reduction and observation times, and the frequency of POCUS and positive US results between the 2 groups. RESULTS: Of 160 children with CNI, 93 visited the emergency department since May 2014. The POST group showed a shorter median EDLOS (856 vs 630 minutes, P < 0.001), door-to-reduction time (137 vs 111 minutes, P = 0.002), and observation time (700 vs 532 minutes, P < 0.001). The POST group had a higher frequency of POCUS (12% vs 60%, P < 0.001) with positive US results (33% vs 59%, P < 0.001). The PRE group had a higher frequency of severe bowel edema (16% vs 1%, P < 0.001). No significant differences were found in the severity, recurrence, admission, and surgery. One child had a false-negative result on POCUS. CONCLUSIONS: Point-of-care ultrasound could streamline the workflow of CNI via decrease in EDLOS and unnecessary referrals for US.

Implications of Increased Weight Status for the Occurrence of Fall-Induced Intracranial Hemorrhage in Children Aged 4 Years or Younger.

OBJECTIVES: The aim of this study was to investigate the association between increased weight status (IWS), a weight for age/sex at greater than the 95th percentile, and fall-induced intracranial hemorrhage (ICH) in children aged 4 years or younger. METHODS: In 7072 children aged 4 years or younger with head injury who visited a tertiary care hospital emergency department in Korea from 2013 through 2015, the presence of fall-induced ICH was reviewed. The association between IWS and ICH was investigated by multivariable logistic regression. We retrospectively validated the Pediatric Emergency Care Applied Research Network rule alone and in combination with IWS for predicting ICH. RESULTS: Of 7072 children, 547 (7.7%) underwent computed tomography, of whom 451 (6.4%) were enrolled. Of these, 41 (9.1%; estimated event rate, 0.6%) had ICHs, and 26 (5.8%) had IWS. Increased weight status was more common in the children with ICH (P = 0.023). The association between IWS and ICH remained significant after adjustment (odds ratio, 5.24; 95% confidence interval [CI], 1.49-18.46; P = 0.010). The validation of the rule in combination with IWS showed no significant increases in a sensitivity (92.7% [95% CI, 80.1%-98.5%] to 95.7% [95% CI, 83.5%-99.4%]) and negative predictive value (98.2% [95% CI, 94.7%-99.4%] to 98.8% [95% CI, 95.4%-99.8%]). CONCLUSIONS: Increased weight status is associated with fall-induced ICH in children aged 4 years or younger. Information on weight status could be potentially helpful in predicting ICH in young children with fall-induced head injury.

Risk Stratification of Intermediate-Risk Children With Minor Head Injury.

The Pediatric Emergency Care Applied Research Network rule helps emergency physicians identify very low-risk children with minor head injury who can forgo head computed tomography. This rule contributes to reduction in lifetime risk of radiation-induced cancers while minimizing missing clinically important traumatic brain injury. However, in intermediate-risk children, decisions on whether to perform computed tomography remain at the emergency physicians' discretion. To reduce this gray zone, this review summarizes evidence for risk stratification of intermediate-risk children with minor head injury.

Viral binding-induced signaling drives a unique and extended intracellular trafficking pattern during infection of primary monocytes.

We initiated experiments to examine the infection of monocytes postentry. New data show that human cytomegalovirus (HCMV) DNA is detected in the nucleus beginning only at 3 d postinfection in monocytes, compared with 30 min postinfection in fibroblasts and endothelial cells, suggesting that HCMV nuclear translocation in monocytes is distinct from that seen in other cell types. We now show that HCMV is initially retained in early endosomes and then moves sequentially to the trans-Golgi network (TGN) and recycling endosomes before nuclear translocation. HCMV is retained initially as a mature particle before deenvelopment in recycling endosomes. Disruption of the TGN significantly reduced nuclear translocation of viral DNA, and HCMV nuclear translocation in infected monocytes was observed only when correct gH/gL/UL128-131/integrin/c-Src signaling occurred. Taken together, our findings show that viral binding of the gH/gL/UL128-131 complex to integrins and the ensuing c-Src signaling drive a unique nuclear translocation pattern that promotes productive infection and avoids viral degradation, suggesting that it represents an additional viral evasion/survival strategy.

High Concentration of C-Reactive Protein Is Associated With Serious Bacterial Infection in Previously Healthy Children Aged 3 to 36 Months With Fever and Extreme Leukocytosis.

OBJECTIVES: The aim of the study was to investigate the diagnostic efficacy of C-reactive protein (CRP) in predicting serious bacterial infection (SBI) in febrile children aged 3 to 36 months with extreme leukocytosis (EL), defined as a peripheral white blood cell count of 25,000 to 49,999/mm. METHODS: The presence of SBI was reviewed in previously healthy children aged 3 to 36 months with a fever of 39°C or higher and EL, who visited a tertiary care hospital emergency department between September 2010 and August 2015. We measured cutoff values of CRP with corresponding likelihood ratios (LRs) and posttest probabilities (PPs). RESULTS: Of 9989 febrile children, 4252 (42.6%) underwent assays for white blood cell and CRP. Of 233 (5.5%) children with EL, 133 (3.1%) were enrolled, of whom 43 (32.3%; 95% confidence interval [CI], 25.0%-40.7%) had SBI, including 33 pyelonephritis, 5 deep abscesses, 3 lobar pneumonia, and 2 soft tissue infections. With the cutoff of 7.8 mg/dL, the sensitivity of CRP in predicting SBI was 81.4% (95% CI, 67.4%-90.3%); the specificity, 80.0% (95% CI, 70.6%-87.0%); the positive predictive value, 66.0% (95% CI, 52.6%-77.3%); the negative predictive value, 90.0% (95% CI, 81.5%-94.9%); the positive LR, 4.1; and the PP, 66.0% (95% CI, 55.6%-75.0%). A CRP concentration of 16.1 mg/dL or higher yielded an LR of 11.2 and a PP of 84.2% (95% CI, 62.1%-94.5%). A CRP concentration of lower than 3.4 mg/dL yielded an LR of 0.05 and a PP of 2.4% (95% CI, 0.3%-14.6%). CONCLUSIONS: High concentration of CRP is strongly associated with the presence of SBI in febrile children with EL.

Requirement for Head Magnetic Resonance Imaging in Children Who Present to the Emergency Department With Acute Nontraumatic Visual Disturbance.

OBJECTIVES: This study aimed to investigate the clinical features and head magnetic resonance imaging (MRI) findings in children who presented to the emergency department with acute nontraumatic visual disturbance and to study related clinical factors for discovering positive lesions on head MRI. METHODS: We performed a retrospective study of 1-month to 15-year-old children who underwent head MRI as an evaluation for acute nontraumatic visual disturbance as a chief complaint in our pediatric emergency department between March 2010 and March 2015. The symptoms of visual disturbance were blurred vision, diplopia, loss of vision, and visual hallucination. Head MRI findings were considered positive when lesions could explain the symptoms. RESULTS: We identified 39 patients (25 with blurred vision, 9 with diplopia, 3 with loss of vision, and 2 with visual hallucination) with a mean age of 8.35 ± 4.06 years. Positive head MRI findings were identified in 13 patients (33.3%). Brain tumors were most common (53.8%), followed by optic nerve inflammations (23.1%), congenital brain lesions (15.4%), and hypertensive encephalopathy (7.7%). Compared with the negative head MRI group, the positive head MRI group showed significantly less transient visual disturbance (duration <1 hour to complete recovery) (P = 0.001), more limited eye movement (P = 0.003), and more pupillary abnormalities (P = 0.030). CONCLUSIONS: We suggest performing urgent head MRI in children with acute nontraumatic visual disturbance if the symptoms last longer than 1 hour without complete recovery and are accompanied by limited eye movement or pupillary abnormality.

Human Cytomegalovirus Requires Epidermal Growth Factor Receptor Signaling To Enter and Initiate the Early Steps in the Establishment of Latency in CD34+ Human Progenitor Cells.

The establishment of human cytomegalovirus (HCMV) latency and persistence relies on the successful infection of hematopoietic cells, which serve as sites of viral persistence and contribute to viral spread. Here, using blocking antibodies and pharmacological inhibitors, we document that HCMV activation of the epidermal growth factor receptor (EGFR) and downstream phosphatidylinositol 3-kinase (PI3K) mediates viral entry into CD34+ human progenitor cells (HPCs), resulting in distinct cellular trafficking and nuclear translocation of the virus compared to that in other immune cells, such as we have documented in monocytes. We argue that the EGFR allows HCMV to regulate the cellular functions of these replication-restricted cells via its signaling activity following viral binding. In addition to regulating HCMV entry/trafficking, EGFR signaling may also shape the early steps required for the successful establishment of viral latency in CD34+ cells, as pharmacological inhibition of EGFR increases the transcription of lytic IE1/IE2 mRNA while curbing the expression of latency-associated UL138 mRNA. EGFR signaling following infection of CD34+ HPCs may also contribute to changes in hematopoietic potential, as treatment with the EGFR kinase (EGFRK) inhibitor AG1478 alters the expression of the cellular hematopoietic cytokine interleukin 12 (IL-12) in HCMV-infected cells but not in mock-infected cells. These findings, along with our previous work with monocytes, suggest that EGFR likely serves as an important determinant of HCMV tropism for select subsets of hematopoietic cells. Moreover, our new data suggest that EGFR is a key receptor for efficient viral entry and that the ensuing signaling regulates important early events required for successful infection of CD34+ HPCs by HCMV.IMPORTANCE HCMV establishes lifelong persistence within the majority of the human population without causing overt pathogenesis in healthy individuals. Despite this, reactivation of HCMV from its latent reservoir in the bone marrow causes significant morbidity and mortality in immunologically compromised individuals, such as bone marrow and solid organ transplant patients. Lifelong persistent infection has also been linked with the development of various cardiovascular diseases in otherwise healthy individuals. Current HCMV therapeutics target lytic replication, but not the latent viral reservoir; thus, an understanding of the molecular basis for viral latency and persistence is paramount to controlling or eliminating HCMV infection. Here, we show that the viral signalosome activated by HCMV binding to its entry receptor, EGFR, in CD34+ HPCs initiates early events necessary for successful latent infection of this cell type. EGFR and associated signaling players may therefore represent promising targets for mitigating HCMV persistence.

Human Cytomegalovirus Utilizes a Nontraditional Signal Transducer and Activator of Transcription 1 Activation Cascade via Signaling through Epidermal Growth Factor Receptor and Integrins To Efficiently Promote the Motility, Differentiation, and Polarization of Infected Monocytes.

Human cytomegalovirus (HCMV) infects peripheral blood monocytes and triggers biological changes that promote viral dissemination and persistence. We have shown that HCMV induces a proinflammatory state in infected monocytes, resulting in enhanced monocyte motility and transendothelial migration, prolonged monocyte survival, and differentiation toward a long-lived M1-like macrophage phenotype. Our data indicate that HCMV triggers these changes, in the absence of de novo viral gene expression and replication, through engagement and activation of epidermal growth factor receptor (EGFR) and integrins on the surface of monocytes. We previously identified that HCMV induces the upregulation of multiple proinflammatory gene ontologies, with the interferon-associated gene ontology exhibiting the highest percentage of upregulated genes. However, the function of the HCMV-induced interferon (IFN)-stimulated genes (ISGs) in infected monocytes remained unclear. We now show that HCMV induces the enhanced expression and activation of a key ISG transcriptional regulator, signal transducer and activator of transcription (STAT1), via an IFN-independent but EGFR- and integrin-dependent signaling pathway. Furthermore, we identified a biphasic activation of STAT1 that likely promotes two distinct phases of STAT1-mediated transcriptional activity. Moreover, our data show that STAT1 is required for efficient early HCMV-induced enhanced monocyte motility and later for HCMV-induced monocyte-to-macrophage differentiation and for the regulation of macrophage polarization, suggesting that STAT1 may serve as a molecular convergence point linking the biological changes that occur at early and later times postinfection. Taken together, our results suggest that HCMV reroutes the biphasic activation of a traditionally antiviral gene product through an EGFR- and integrin-dependent pathway in order to help promote the proviral activation and polarization of infected monocytes.IMPORTANCE HCMV promotes multiple functional changes in infected monocytes that are required for viral spread and persistence, including their enhanced motility and differentiation/polarization toward a proinflammatory M1 macrophage. We now show that HCMV utilizes the traditionally IFN-associated gene product, STAT1, to promote these changes. Our data suggest that HCMV utilizes EGFR- and integrin-dependent (but IFN-independent) signaling pathways to induce STAT1 activation, which may allow the virus to specifically dictate the biological activity of STAT1 during infection. Our data indicate that HCMV utilizes two phases of STAT1 activation, which we argue molecularly links the biological changes that occur following initial binding to those that continue to occur days to weeks following infection. Furthermore, our findings may highlight a unique mechanism for how HCMV avoids the antiviral response during infection by hijacking the function of a critical component of the IFN response pathway.

Performance of MRI for suspected appendicitis in pediatric patients and negative appendectomy rate: A systematic review and meta-analysis.

PURPOSE: To evaluate in pediatric patients the diagnostic performance of magnetic resonance imaging (MRI) for suspected appendicitis and its negative appendectomy rate. MATERIALS AND METHODS: The study involved diagnostic accuracy studies that used MRI for pediatric patients with suspected appendicitis. Various field strengths and sequences were used in each included study. The diagnostic accuracy of MRI in pediatric patients with suspected appendicitis and negative appendectomy rate were assessed. A search of MEDLINE and EMBASE databases was performed until January 10, 2017. Two reviewers assessed the methodological quality of the articles using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Pooled sensitivity and specificity for appendicitis diagnosis were calculated using hierarchical logistic regression modeling. Meta-regression was performed to explore factors affecting study heterogeneity. The pooled negative appendectomy rate was analyzed. RESULTS: Thirteen original articles with 1946 patients were included. The summary sensitivity and specificity were 97% (95% confidence interval [CI], 95-98%) and 97% (95% CI, 93-98%), respectively; the area under the hierarchical summary receiver operating characteristic (HSROC) curve was 0.98 (95% CI, 0.97-0.99). In meta-regression, use of diffusion-weighted imaging (P < 0.01) and age (P < 0.01) affected heterogeneity, but there was no difference according to intravenous contrast agent use (P = 0.95). The pooled negative appendectomy rate of MRI was 4.5% (95% CI, 1.9-7.1%). CONCLUSION: MRI shows excellent diagnostic performance for appendicitis in pediatric patients regardless of the use of intravenous contrast media. Therefore, nonenhanced-only MRI protocols might be appropriate for pediatric patients with suspected appendicitis. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:767-778.

The diagnostic performance of reduced-dose CT for suspected appendicitis in paediatric and adult patients: A systematic review and diagnostic meta-analysis.

OBJECTIVE: To evaluate the diagnostic performance of reduced-dose CT for suspected appendicitis. METHODS: A systematic search of the MEDLINE and EMBASE databases was carried out through to 10 January 2017. Studies evaluating the diagnostic performance of reduced-dose CT for suspected appendicitis in paediatric and adult patients were selected. Pooled summary estimates of sensitivity and specificity were calculated using hierarchical logistic regression modelling. Meta-regression was performed. RESULTS: Fourteen original articles with a total of 3,262 patients were included. For all studies using reduced-dose CT, the summary sensitivity was 96 % (95 % CI 93-98) with a summary specificity of 94 % (95 % CI 92-95). For the 11 studies providing a head-to-head comparison between reduced-dose CT and standard-dose CT, reduced-dose CT demonstrated a comparable summary sensitivity of 96 % (95 % CI 91-98) and specificity of 94 % (95 % CI 93-96) without any significant differences (p=.41). In meta-regression, there were no significant factors affecting the heterogeneity. The median effective radiation dose of the reduced-dose CT was 1.8 mSv (1.46-4.16 mSv), which was a 78 % reduction in effective radiation dose compared to the standard-dose CT. CONCLUSION: Reduced-dose CT shows excellent diagnostic performance for suspected appendicitis. KEY POINTS: • Reduced-dose CT shows excellent diagnostic performance for evaluating suspected appendicitis. • Reduced-dose CT has a comparable diagnostic performance to standard-dose CT. • Median effective radiation dose of reduced-dose CT was 1.8 mSv (1.46-4.16). • Reduced-dose CT achieved a 78 % dose reduction compared to standard-dose CT.

Reactive oxygen species-induced parthanatos of immunocytes by human cytomegalovirus-associated substance.

Previous studies have examined various immune evasion strategies of human cytomegalovirus (HCMV) to gain understanding of its pathogenesis. Although the mechanism that underlies immunocyte destruction near HCMV-infected lesions has yet to be established, it is here shown that substances produced by HCMV-infected cells induce death in several types of immunocytes, but not in fibroblasts or astrocytomas. These substances contain HCMV proteins and were termed HCMV-associated insoluble substance (HCMVAIS). The mechanism by which HCMVAIS induces cell death was characterized to improve understanding the death of immunocytes near HCMV-infected lesions. HCMVAIS were found to trigger production of intracellular nicotinamide adenine dinucleotide phosphate oxidase-derived reactive oxygen species (ROS), resulting in cell death, this effect being reversed following treatment with ROS inhibitors. Cell death was not induced in splenocytes from NOX-2 knockout mice. It was hypothesized that DNA damage induced by oxidative stress initiates poly ADP-ribose polymerase-1 (PARP-1)-mediated cell death, or parthanatos. HCMVAIS-induced cell death is accompanied by PARP-1 activation in a caspase-independent manner, nuclear translocation of apoptosis-inducing factor (AIF), and DNA fragmentation, which are typical features of parthanatos. Treatment with an AIF inhibitor decreased the rate of HCMVAIS-induced cell death, this being confirmed by hematoxylin and eosin staining; cell death in most HCMV-positive foci in serial section samples of a large intestine with HCMV infection was TUNEL-positive, cleaved caspase 3-negative and CD45-positive. Taken together, these data suggest that HCMV inhibits local immune responses via direct killing of immunocytes near HCMV-infected cells through ROS-induced parthanatos by HCMVAIS.

Changes of Epidemiological Characteristics of Japanese Encephalitis Viral Infection and Birds as a Potential Viral Transmitter in Korea.

Japanese encephalitis (JE) cases have been increasingly reported recently especially in Seoul and its vicinity. Pigs are known as amplifying host of JE virus (JEV), but do not play an important role in these recent events because pig-breeding is not common in Seoul. The distribution and the density of migratory birds are correlated with JE cases in cities and they might be highly potential hosts contributing to transmit JEV in metropolitan areas. JE genotype and sero-prevalence in birds should be determined for the verification of the transmission route of JEV in the recent sporadic occurrence of JE cases in Seoul.

Risk Factors for Recurrent Intussusception After Fluoroscopy-Guided Air Enema.

OBJECTIVES: The aim of this study was to identify risk factors for recurrent intussusception after a successful reduction by fluoroscopy-guided air enema, the time required for recurrence, and the association between delayed reduction and the recurrence. METHODS: Medical records of 479 consecutive children with intussusception who underwent fluoroscopy-guided air enema between January 2004 and September 2014 were reviewed. Recurrent intussusception was defined as a recurrence within 48 hours of a reduction. Symptom-to-door time was defined as the time from symptom onset to emergency department arrival. Door-to-reduction time was defined as the time from emergency department arrival to reduction. Time-to-recurrence was defined as the time required for recurrence from the first ultrasound diagnosis. RESULTS: Of the 360 eligible children, 32 had recurrent intussusceptions (8.9%). Multivariable logistic regression showed that age 2 years or older is an independent predictor of recurrent intussusception (odds ratio, 2.39; 95% confidence interval, 1.13-5.02; P = 0.02). Median time to recurrence was 25 hours (18.0-36.0 hours). Although symptom-to-door and door-to-reduction times tended to be longer in the recurrence group, these differences were not significant (12.5 vs 7.0 hours, P = 0.18; 154.0 vs 143.0 minutes, P = 0.67, respectively). CONCLUSIONS: Our data suggest that provision for early recurrence and extended observation may be beneficial for children 2 years or older. Delayed reduction was not associated with recurrent intussusception, but further studies with larger sample sizes are needed to explain this issue.