Network pharmacology and transcriptomics to determine Danggui Yifei Decoction mechanism of action for the treatment of chronic lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Several children with pneumonia (especially severe cases) have symptoms of cough and expectoration during the recovery stage after standard symptomatic treatment, which eventually results in chronic lung injury. Danggui yifei Decoction (DGYFD), a traditional Chinese formula, has shown clinical promise for the treatment of chronic lung injury during the recovery stage of pneumonia, however, its mechanism of action is yet to be deciphered.

AIM OF THIS STUDY

To investigate the therapeutic mechanism of DGYFD for the treatment of chronic lung injury by integrating network pharmacology and transcriptomics.

MATERIALS AND METHODS

BALB/c mice were used to establish the chronic lung injury mouse model by intratracheal instillation of lipopolysaccharide (LPS). Pathological analysis of lung tissue, lung injury histological score, lung index, protein levels in bronchoalveolar lavage fluid (BALF), immunohistochemical staining, blood rheology, inflammatory cytokines, and oxidative stress levels were used to evaluate the pharmacological effects of DGYFD. Chemical components of DGYFD were identified using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Integrated network pharmacology together with transcriptomics was used to predict potential biological targets. Western blot analysis was used to verify the results.

RESULTS

In this study, we demonstrated that DGYFD could improve lung injury pathological changes, decreases lung index, down-regulate NO and IL-6 levels, and regulate blood rheology. In addition, DGYFD was able to reduce the protein levels in BALF, up-regulate the expression levels of occludin and ZO-1, improve the ultrastructure of lung tissues, and reverse the imbalance of AT I and AT II cells to repair the alveolar-capillary permeability barrier. Twenty-nine active ingredients of DGYFD and 389 potential targets were identified by UPLC-MS/MS and network pharmacology, and 64 differentially expressed genes (DEGs) were identified using transcriptomics. GO and KEGG analysis revealed that the MAPK pathway may be the molecular target. Further, we found that DGYFD inhibits phosphorylation levels of p38 MAPK and JNK in chronic lung injury mouse models.

CONCLUSIONS

DGYFD could regulate the imbalance between the excessive release of inflammatory cytokines and oxidative stress, repair the alveolar-capillary permeability barrier and improve the pathological changes during chronic lung injury by regulating the MAPK signaling pathway.

Circulating markers of neutrophil activation and lung injury in pediatric pneumonia in low-resource settings

Diagnostic biomarkers for childhood pneumonia could guide management and improve antibiotic stewardship in low-resource settings where chest x-ray (CXR) is not always available. In this cross-sectional study, we measured chitinase 3-like protein 1 (CHI3L1), surfactant protein D (SP-D), lipocalin-2 (LCN2), and tissue inhibitor of metalloproteinases-1 (TIMP-1) in Ugandan children under the age of five hospitalized with acute lower respiratory tract infection. We determined the association between biomarker levels and primary end-point pneumonia, indicated by CXR consolidation. We included 89 children (median age 11 months, 39% female). Primary endpoint pneumonia was present in 22 (25%). Clinical signs were similar in children with and without CXR consolidation. Broad-spectrum antibiotics (ceftriaxone) were administered in 83 (93%). Levels of CHI3L1, SP-D, LCN2 and TIMP-1 were higher in patients with primary end-point pneumonia compared to patients with normal CXR or other infiltrates. All markers were moderately accurate predictors of primary end-point pneumonia, with area under receiver operator characteristic curves of 0.66-0.70 (p<0.05 for all markers). The probability of CXR consolidation increased monotonically with the number of markers above cut-off. Among 28 patients (31%) in whom all four markers were below the cut-off, the likelihood ratio of CXR consolidation was 0.11 (95%CI 0.015 to 0.73). CHI3L1, SP-D, LCN2 and TIMP-1 were associated with CXR consolidation in children with clinical pneumonia in a low-resource setting. Combinations of quantitative biomarkers may be useful to safely withhold antibiotics in children with a low probability of bacterial infection.

Three-dimensional ultrashort echo time magnetic resonance imaging in pediatric patients with pneumonia: a comparative study

BACKGROUND

UTE has been used to depict lung parenchyma. However, the insufficient discussion of its performance in pediatric pneumonia compared with conventional sequences is a gap in the existing literature. The objective of this study was to compare the diagnostic value of 3D-UTE with that of 3D T1-GRE and T2-FSE sequences in young children diagnosed with pneumonia.

METHODS

Seventy-seven eligible pediatric patients diagnosed with pneumonia at our hospital, ranging in age from one day to thirty-five months, were enrolled in this study from March 2021 to August 2021. All patients underwent imaging using a 3 T pediatric MR scanner, which included three sequences: 3D-UTE, 3D-T1 GRE, and T2-FSE. Subjective analyses were performed by two experienced pediatric radiologists based on a 5-point scale according to six pathological findings (patchy shadows/ground-glass opacity (GGO), consolidation, nodule, bulla/cyst, linear opacity, and pleural effusion/thickening). Additionally, they assessed image quality, including the presence of artifacts, and evaluated the lung parenchyma. Interrater agreement was assessed using intraclass correlation coefficients (ICCs). Differences among the three sequences were evaluated using the Wilcoxon signed-rank test.

RESULTS

The visualization of pathologies in most parameters (patchy shadows/GGO, consolidation, nodule, and bulla/cyst) was superior with UTE compared to T2-FSE and T1 GRE. The visualization scores for linear opacity were similar between UTE and T2-FSE, and both were better than T1-GRE. In the case of pleural effusion/thickening, T2-FSE outperformed the other sequences. However, statistically significant differences between UTE and other sequences were only observed for patchy shadows/GGO and consolidation. The overall image quality was superior or at least comparable with UTE compared to T2-FSE and T1-GRE. Interobserver agreements for all visual assessments were significant and rated "substantial" or "excellent."

CONCLUSIONS

In conclusion, UTE MRI is a useful and promising method for evaluating pediatric pneumonia, as it provided better or similar visualization of most imaging findings compared with T2-FSE and T1-GRE. We suggest that the UTE MRI is well-suited for pediatric population, especially in younger children with pneumonia who require longitudinal and repeated imaging for clinical care or research and are susceptible to ionizing radiation.

Incidence of non-invasive all-cause pneumonia in children in the United States before and after the introduction of pneumococcal conjugate vaccines: a retrospective claims database analysis

BACKGROUND

Pneumonia is the most serious form of acute respiratory infection and Streptococcus pneumoniae is a leading cause of pediatric bacterial pneumonia. Pneumococcal conjugate vaccines were introduced in the United States (US) in 2000 (7-valent [PCV7]) and 2010 (13-valent [PCV13]). This study estimated annual incidence rates (IRs) of all-cause pneumonia (ACP) among US children aged < 18 years before and after the introduction of PCV7 and PCV13.

METHODS

ACP episodes were identified in the IBM MarketScan Commercial and Medicaid Databases using diagnosis codes. Annual IRs were calculated overall and by inpatient and outpatient settings as the number of episodes per 100,000 person-years (PY) for all children aged < 18 years and by age group (< 2, 2-4, and 5-17 years). National estimates of annual pneumonia IRs were extrapolated using Census Bureau data. Interrupted time series (ITS) analyses were used to assess immediate and gradual changes in monthly pneumonia IRs, adjusting for seasonality.

RESULTS

In the commercially-insured population, ACP IRs declined between the pre-PCV7 period (1998-1999) and late PCV13 period (2014-2018) from 5,322 to 3,471 episodes per 100,000 PY for children aged < 2 years, from 4,012 to 3,794 episodes per 100,000 PY in children aged 2-4 years but increased slightly from 1,383 to 1,475 episodes per 100,000 PY in children aged 5-17 years. The ITS analyses indicated significant decreases in monthly ACP IRs in the early PCV7 period (2001-2005) among younger children and in the early PCV13 period (2011-2013) among all children. Increases were observed in the late PCV7 period (2006-2009) among all age groups, but were only significant among older children. IRs of inpatient ACP decreased across all age groups, but outpatient pneumonia IRs remained stable during the study timeframe, even increasing slightly in children aged 5-17 years. More prominent declines were observed for Medicaid-insured children across all age groups; however, Medicaid IRs were higher than IRs of commercially-insured children during the entire study timeframe.

CONCLUSIONS

ACP disease burden remains high in US children of all ages despite overall reductions in incidence rates during 1998-2018 following the introduction of PCV7 and PCV13.

The binding affinity of human pediatric respiratory syncytial virus Phosphoprotein's C-terminal tail to nucleocapsid can be improved by a rationally designed halogen-bonded system

Human respiratory syncytial virus (hRSV) is a common contagious virus that causes infections of pediatric pneumonia and specifically impacts infants and small children. The hRSV phosphoprotein is a key component of the viral RNA polymerase, which can interact with nucleocapsid and other partners through its C-terminal tail (CTT) to promote the formation of viral transcriptase complex, where the Phe241 is a key anchor residue. Based on the crystal template-modeled complex structure of hRSV nucleocapsid with a peptidic segment derived from the phosphoprotein's CTT, we successfully introduced a rationally designed halogen-bonded system to the complex interface by substituting para (p)-position of the side-chain phenyl moiety of CTT Phe241 residue with a halogen atom X (X = F, Cl, Br or I). The halogen-bonded system consists of a halogen bond (X-bond) between nucleocapsid Ser131 residue and CTT Phe241 residue as well as a hydrogen bond (H-bond) between nucleocapsid Ser131 residue and nucleocapsid Glu128 residue; the X-bond and H-bond share a common hydroxyl group of nucleocapsid Ser131 residue. High-level theoretical calculations suggested that bromine Br is the best choice that can render strong potency for the X-bond and can confer high affinity to the nucleocapsid-CTT binding. Affinity analysis revealed that the p-brominated CTT ([p]bCTT) exhibited 6.3-fold affinity improvement relative to its nonhalogenated counterpart. In contrast, the Br-substitutions at ortho (o)- and meta (m)-positions, which resulted in two negative controls of o-brominated [o]bCTT and m-brominated [m]bCTT, respectively, were unable to form effective X-bond with nucleocapsid according to theoretical investigation and did not improve the binding affinity essentially relative to native CTT.

Structural modeling, energetic analysis and molecular design of a π-stacking system at the complex interface of pediatric respiratory syncytial virus nucleocapsid with the C-terminal peptide of phosphoprotein

Human respiratory syncytial virus (RSV) is a primary cause of lower respiratory tract infections and hospital visits during infancy and childhood. The RSV phosphoprotein (P) is a major polymerase cofactor that interacts with nucleoprotein (N) to promote the recognition of ribonucleoprotein complex (RNP) by viral RNA polymerase. The binding pocket of N protein is chemically diverse, in or around which a number of aromatic and charged amino acid residues are observed. Previously, a nonapeptide segment (P peptide, ²³³DNDLSLEDF²⁴¹) representing the C-terminal tail of P protein was identified to mediate the N-P interaction with a moderate affinity, in which the Phe241 at the end of P's C-terminus plays a critical role in the binding of P peptide to N protein. Here, we found that the side-chain aromatic phenyl moiety of P Phe241 residue can form short- and long-range cation-π interactions with N Arg132 and Arg150 residues, respectively, as well as T-shaped and parallel-displaced π-π stackings with N Tyr135 and His151 residues, respectively, which co-define a geometrically satisfactory π-stacking system at the complex interface of N protein with P peptide, thus largely stabilizing the complex architecture. The stacking effect was further optimized by systematically mutating the P Phe241 residue to other natural and non-natural aromatic amino acids with diverse chemical substitutions at the phenyl moiety to examine their structural and energetic effects on π-stacking system and on protein-peptide binding. The electron-donating mutations at the phenyl moiety of P Phe241 residue can effectively enhance the π-stacking system and then promote peptide binding, whereas the bulky and positively charged mutations would considerably impair the peptide potency by introducing steric hindrance and electrostatic repulsion. The [Tyr]P, [Thp]P and [Fph]P mutants were determined to have an increased affinity relative to wild-type P peptide, which could be used as self-inhibitory peptides to competitively disrupt the native interaction between N and P proteins.

Pediatric pneumonia diagnosis using stacked ensemble learning on multi-model deep CNN architectures

Pediatric pneumonia has drawn immense awareness due to the high mortality rates over recent years. The acute respiratory infection caused by bacteria, viruses, or fungi infects the lung region and hinders oxygen transport, making breathing difficult due to inflamed or pus and fluid-filled alveoli. Being non-invasive and painless, chest X-rays are the most common modality for pediatric pneumonia diagnosis. However, the low radiation levels for diagnosis in children make accurate detection challenging. This challenge initiates the need for an unerring computer-aided diagnosis model. Our work proposes Contrast Limited Adaptive Histogram Equalization for image enhancement and a stacking classifier based on the fusion of deep learning-based features for pediatric pneumonia diagnosis. The extracted features from the global average pooling layers of the fine-tuned MobileNet, DenseNet121, DenseNet169, and DenseNet201 are concatenated for the final classification using a stacked ensemble classifier. The stacking classifier uses Support Vector Classifier, Nu-SVC, Logistic Regression, K-Nearest Neighbor, Random Forest Classifier, Gaussian Naïve Bayes, AdaBoost classifier, Bagging Classifier, and Extra-trees Classifier for the first stage, and Nu-SVC as the meta-classifier. The stacking classifier validated using Stratified K-Fold cross-validation achieves an accuracy of 98.62%, precision of 98.99%, recall of 99.53%, F1 score of 99.26%, and an AUC score of 93.17% on the publicly available pediatric pneumonia dataset. We expect this model to greatly help the real-time diagnosis of pediatric pneumonia.

Pellino2 accelerate inflammation and pyroptosis via the ubiquitination and activation of NLRP3 inflammation in model of pediatric pneumonia

BACKGROUND

Mycoplasma pneumoniae pneumonia (MPP) is a common and frequently-occurring disease in pediatrics. This study aims to via unveiling the novel effects and mechanisms of Pellino2 in model of pediatric pneumonia.

MATERIALS AND METHODS

Male infancy C57BL/6 mice were injected with 2 mg/kg of LPS (Sigma-Aldrich Merck KGaA). THP-1 cells were induced with LPS and ATP.

RESULTS

The expression of Pellino2 mRNA and protein in patients with pediatric pneumonia or mice with pediatric pneumonia were reduced. Pellino2 accelerated lung injury and expanded inflammation and pyroptosis in lung tissue of pediatric pneumonia in vivo and vitro model. Furthermore, the inhibition of Pellino2 reduced lung injury and weakened inflammation and pyroptosis in lung tissue of pediatric pneumonia in vivo and vitro model. Pellino2 protein catenated NLRP3 protein, and Pellino2 promoted ubiquitination and activation of NLRP3 inflammation in model of pediatric pneumonia. Pellino2 accelerate inflammation and pyroptosis in model of pediatric pneumonia by NLRP3.

CONCLUSIONS

These results suggest that Pellino2 accelerate inflammation and pyroptosis via the induction of ubiquitination and activation of NLRP3 inflammation in model of pediatric pneumonia, Pellino2 may serve as a potential approach for the treatment of pediatric pneumonia and other inflammatory diseases.

Soluble T cell immunoglobulin and mucin-domain containing protein 3 in children hospitalized with pneumonia in resource-limited settings

In a prospective cohort study of 77 children with severe pneumonia from two hospitals in Uganda, we assessed soluble T cell immunoglobulin and mucin-domain containing protein 3 (sTIM-3) levels at hospital admission and their association with pneumonia severity and subsequent mortality. sTIM-3 levels were positively correlated with the Respiratory Index of Severity in Children (RISC) (ρ = 0.35, p = 0.0017), sTIM-3 levels were higher in children who required transfer to a tertiary hospital (p = 0.014) and in fatal cases (p = 0.011). In summary, sTIM-3 is associated with disease severity and predictive of mortality in childhood pneumonia in resource-limited settings.

Interleukin-18 binding protein in infants and children hospitalized with pneumonia in low-resource settings

Pneumonia is the leading infectious cause of death in children, with especially high mortality in low- and middle-income countries. Interleukin-18 binding protein (IL-18BP) is a natural antagonist of the pro-inflammatory cytokine interleukin-18 and is elevated in numerous autoimmune conditions and infectious diseases. We conducted a prospective cohort study to determine the association between admission IL-18BP levels and clinical severity among children admitted to two hospitals in Uganda for hypoxemic pneumonia. A total of 42 children (median age of 1.2 years) were included. IL-18BP levels were higher in patients with respiratory distress, including chest indrawing (median 15 ng/mL (IQR 9.8-18) versus 4.5 ng/mL (IQR 3.8-11) without chest indrawing, P = 0.0064) and nasal flaring (median 15 ng/mL (IQR 9.7-19) versus 11 ng/mL (IQR 5.4-14) without nasal flaring, P = 0.034). IL-18BP levels were positively correlated with the composite clinical severity score, Pediatric Early Death Index for Africa (PEDIA-e, ρ = 0.46, P = 0.0020). Patients with IL-18BP > 14 ng/mL also had slower recovery times, including time to sit (median 0.69 days (IQR 0.25-1) versus 0.15 days (IQR 0.076-0.36) with IL-18BP < 14 ng/mL, P = 0.036) and time to fever resolution (median 0.63 days (IQR 0.16-2) versus 0.13 days (IQR 0-0.42), P = 0.016). In summary, higher IL-18BP levels were associated with increased disease severity and prolonged recovery times in Ugandan children with pneumonia.

Disulfide-stapled design of α-helical bundles to target the trimer-of-hairpins motif of human respiratory syncytial virus fusion protein

Human respiratory syncytial virus (RSV) is the major cause of acute lower respiratory tract infections worldwide in infants and young children. The RSV F glycoprotein is a class I fusion protein that mediates viral entry into host cells and is a major target of neutralizing antibodies. Targeting F glycoprotein has been recognized as a promising antiviral therapeutic strategy against RSV infection. Here, we reported the disulfide-stapled design of α-helical bundle to target the trimer-of-hairpins (TOH) motif of RSV F glycoprotein, which is the central regulatory module that triggers viral membrane fusion event. In TOH motif, three N-terminal heptad repeat (NtHR) helices form a trimeric coiled-coil core and other three C-terminal heptad repeat (CtHR) helices add to the core in an antiparallel manner. Interaction analysis between NtHR and CtHR revealed that the C-terminal tail of CtHR packs tightly against NtHR as compared to the N-terminal and middle regions of CtHR. A core binding site in CtHR C-terminus was identified, which represents a 13-mer chp peptide and can effectively interact with NtHR helix in native ordered conformation but would become largely disordered when splitting from the protein context of CtHR helix. Two chp helices were stapled together in a parallel manner with single, double or triple disulfide bridges, thus systematically resulting in seven disulfide-stapled α-helical bundles. Molecular simulations revealed that the double and triple stapling can effectively stabilize the structured conformation of α-helical bundles, whereas the free conformation of single-stapled bundles still remain intrinsically disordered in solvent. The double-stapled bundle chp-ds[508,516] and the triple-stapled bundle chp-ts[508,512,516] were rationally designed to have high potency; they can form a tight three-helix bundle with NtHR helix, thus potently targeting NtHR-CtHR interactions involved in RSV-F TOH motif through a competitive disruption mechanism.

Knockdown of circ-UQCRC2 ameliorated lipopolysaccharide-induced injury in MRC-5 cells by the miR-326/PDCD4/NF-κB pathway

BACKGROUND

Circular RNAs (circRNAs) have been shown as important modulators in the pathogenesis of pediatric pneumonia. In this paper, we focused on the molecular basis of circRNA ubiquinol-cytochrome c reductase core protein 2 (circ-UQCRC2, circ_0038467) in lipopolysaccharide (LPS)-induced cell injury.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to gauge the levels of circ-UQCRC2, microRNA (miR)-326 and programmed cell death 4 (PDCD4) mRNA. PDCD4 protein expression and the activation of the NF-κB signaling pathway were evaluated by western blot. Ribonuclease R (RNase R) assay was performed to assess the stability of circ-UQCRC2. Cell viability and apoptosis were detected by the Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 were measured by the enzyme-linked immunosorbent assay (ELISA). Targeted relationship between miR-326 and circ-UQCRC2 or PDCD4 was confirmed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays.

RESULTS

Our data showed the up-regulation of circ-UQCRC2 level in pneumonia serum and LPS-treated MRC-5 cells. The silencing of circ-UQCRC2 attenuated LPS-induced MRC-5 cell injury. Mechanistically, circ-UQCRC2 directly targeted miR-326, and circ-UQCRC2 regulated PDCD4 expression through miR-326. MiR-326 was a downstream effector of circ-UQCRC2 function, and PDCD4 was a functional target of miR-326 in regulating LPS-induced MRC-5 cell injury. Additionally, circ-UQCRC2 knockdown inactivated the NF-κB signaling pathway by regulating the miR-326/PDCD4 axis.

CONCLUSION

Our findings demonstrated a novel regulatory network, the miR-326/PDCD4/NF-κB pathway, for the function of circ-UQCRC2 in LPS-induced cell injury in MRC-5 cells.

Early CT Findings of Coronavirus Disease 2019 (COVID-19) in Asymptomatic Children: A Single-Center Experience

OBJECTIVE

The current study reported a case series to illustrate the early computed tomography (CT) findings of coronavirus disease 2019 (COVID-19) in pediatric patients.

MATERIALS AND METHODS

All pediatric patients who were diagnosed with COVID-19 and who underwent CT scan in Zhongnan Hospital of Wuhan University from January 20, 2020 to February 28, 2020 were included in the current study. Data on clinical and CT features were collected and analyzed.

RESULTS

Four children were included in the current study. All of them were asymptomatic throughout the disease course (ranging from 7 days to 15 days), and none of them showed abnormalities in blood cell counts. Familial cluster was the main transmission pattern. Thin-section CT revealed abnormalities in three patients, and one patient did not present with any abnormal CT findings. Unilateral lung involvement was observed in two patients, and one patient showed bilateral lung involvement. In total, five small lesions were identified, including ground-glass opacity (n = 4) and consolidation (n = 1). All lesions had ill-defined margins with peripheral distribution and predilection of lower lobe.

CONCLUSION

Small patches of ground-glass opacity with subpleural distribution and unilateral lung involvement were common findings on CT scans of pediatric patients in the early stage of the disease.

Deep learning, reusable and problem-based architectures for detection of consolidation on chest X-ray images

BACKGROUND AND OBJECTIVE

In most patients presenting with respiratory symptoms, the findings of chest radiography play a key role in the diagnosis, management, and follow-up of the disease. Consolidation is a common term in radiology, which indicates focally increased lung density. When the alveolar structures become filled with pus, fluid, blood cells or protein subsequent to a pulmonary pathological process, it may result in different types of lung opacity in chest radiograph. This study aims at detecting consolidations in chest x-ray radiographs, with a certain precision, using artificial intelligence and especially Deep Convolutional Neural Networks to assist radiologist for better diagnosis.

METHODS

Medical image datasets usually are relatively small to be used for training a Deep Convolutional Neural Network (DCNN), so transfer learning technique with well-known DCNNs pre-trained with ImageNet dataset are used to improve the accuracy of the models. ImageNet feature space is different from medical images and in the other side, the well-known DCNNs are designed to achieve the best performance on ImageNet. Therefore, they cannot show their best performance on medical images. To overcome this problem, we designed a problem-based architecture which preserves the information of images for detecting consolidation in Pediatric Chest X-ray dataset. We proposed a three-step pre-processing approach to enhance generalization of the models. To demonstrate the correctness of numerical results, an occlusion test is applied to visualize outputs of the model and localize the detected appropriate area. A different dataset as an extra validation is used in order to investigate the generalization of the proposed model.

RESULTS

The best accuracy to detect consolidation is 94.67% obtained by our problem based architecture for the understudy dataset which outperforms the previous works and the other architectures.

CONCLUSIONS

The designed models can be employed as computer aided diagnosis tools in real practice. We critically discussed the datasets and the previous works based on them and show that without some considerations the results of them may be misleading. We believe, the output of AI should be only interpreted as focal consolidation. The clinical significance of the finding can not be interpreted without integration of clinical data.

Solar-powered oxygen delivery for the treatment of children with hypoxemia: protocol for a cluster-randomized stepped-wedge controlled trial in Uganda

BACKGROUND

Child mortality due to pneumonia is a major global health problem and is associated with hypoxemia. Access to safe and continuous oxygen therapy can reduce mortality; however, low-income countries may lack the necessary resources for oxygen delivery. We have previously demonstrated proof-of-concept that solar-powered oxygen (SPO2) delivery can reliably provide medical oxygen remote settings with minimal access to electricity. This study aims to demonstrate the efficacy of SPO2 in children hospitalized with acute hypoxemic respiratory illness across Uganda.

METHODS

Objectives: Demonstrate efficacy of SPO2 in children hospitalized with acute hypoxemic respiratory illness.

STUDY DESIGN

Multi-center, stepped-wedge cluster-randomized trial.

SETTING

Twenty health facilities across Uganda, a low-income, high-burden country for pediatric pneumonia. Site selection: Facilities with pediatric inpatient services lacking consistent O2 supply on pediatric wards.

PARTICIPANTS

Children aged < 5 years hospitalized with hypoxemia (saturation < 92%) warranting hospital admission based on clinical judgement. Randomization methods: Random installation order generated a priori with allocation concealment. Study procedure: Patients receive standard of care within pediatric wards with or without SPO2 system installed.

OUTCOME MEASURES

Primary: 48-h mortality. Secondary: safety, efficacy, SPO2 system functionality, operating costs, nursing knowledge, skills, and retention for oxygen administration. Statistical analysis of primary outcome: Linear mixed effects logistic regression model with 48-h mortality (dependent variable) as a function of SPO2 treatment (before versus after installation), while adjusting for confounding effects of calendar time (fixed effect) and site (random effect).

SAMPLE SIZE

2400 patients across 20 health facilities, predicted to provide 80% power to detect a 35% reduction in mortality after introduction of SPO2, based on a computer simulation of > 5000 trials.

DISCUSSION

Overall, our study aims to demonstrate mortality benefit of SPO2 relative to standard (unreliable) oxygen delivery. The innovative trial design (stepped-wedge, cluster-randomized) is supported by a computer simulation. Capacity building for nursing care and oxygen therapy is a non-scientific objective of the study. If successful, SPO2 could be scaled across a variety of resource-constrained remote or rural settings in sub-Saharan Africa and beyond.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03851783. Registered on 22 February 2019.

The Effect of lnterleukin-6 Gene Polymorphism on Pediatric Pneumonia

BACKGROUND

To investigate the effect of interleukin-6 (IL-6) gene polymorphism on pediatric pneumonia.

METHODS

Overall, 438 patients with pediatric pneumonia (Observation group) treated in Xuzhou Children Hospital, Cinna from July 2013 to July 2018 were randomly enrolled. Meanwhile, 423 healthy children (Control group) in the same time period were randomly selected. PCR was applied to amplify the IL-6-572 gene fragment. The IL-6-572 polymorphism was detected, and the impacts of gene polymorphism difference on pediatric pneumonia were observed.

RESULTS

There were differences in the IL-6 genotypes between the two groups (P<0.05). Among the CG+GG genotypes in Observation group, G allele frequency was higher than that in control group (P<0.05). The risk of pediatric pneumonia for GC genotype was 2.13 times as high as that for CC genotype, and the risk of pediatric pneumonia for GG genotype was 5.56 times as high as that for CC genotype.

CONCLUSION

IL-6 gene polymorphism might be related to the pediatric pneumonia and the population with G allele at this locus may be more prone to pediatric pneumonia.

Comparison of serological assays using pneumococcal proteins or polysaccharides for detection of Streptococcus pneumoniae infection in children with community-acquired pneumonia

The aim of this study was to compare the results of serological assays using pneumococcal proteins or polysaccharides for the detection of pneumococcal infection in childhood pneumonia. Serological assays measured IgG against eight pneumococcal proteins (Ply,CbpA,PspA1,PspA2,PcpA,PhtD,StkP-C,PcsB-N), C-polysaccharide [in the whole study population, n = 183], or 19 pneumococcal capsular polysaccharides (1,2,4,5,6B,7F,8,9 V,10A,11A,12F,14,15B,17F,18C,19F,20,23F,33F) [only in a subgroup of patients, n = 53] in paired serum samples of children aged <5 years-old hospitalized with clinical and radiological diagnosis of community-acquired pneumonia. We also performed an inhibition of binding test with the anti-capsular polysaccharide assay in order to confirm the specificity of the antibody responses detected. Invasive pneumococcal pneumonia was investigated by blood culture and PCR (ply-primer). Among 183 children, the anti-protein assay detected antibody response in 77/183(42.1%) patients and the anti-C-polysaccharide assay in 28/183(15.3%) patients. In a subgroup of 53 children, the anti-protein assay detected response in 32/53(60.4%) patients, the anti-C-polysaccharide assay in 11/53(20.8%) patients, and the anti-capsular polysaccharide in 25/53(47.2%) patients. Simultaneous antibody responses against ≥2 different capsular polysaccharides were detected in 11/53(20.8%) patients and this finding could not be explained by cross-reactivity between different serotypes. Among 13 patients with invasive pneumococcal pneumonia, the sensitivity of the anti-protein assay was 92.3%(12/13), of the anti-C-polysaccharide assay 30.8%(4/13), and of the anti-capsular polysaccharide assay 46.2%(6/13). The serological assay using pneumococcal proteins is more sensitive for the detection of pneumococcal infection in children with pneumonia than the assay using pneumococcal polysaccharides. Future studies on childhood pneumonia aetiology should consider applying serological assays using pneumococcal proteins.

Computational redesign of human respiratory syncytial virus epitope as therapeutic peptide vaccines against pediatric pneumonia

Human respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and young children. Here, the RSV fusion (F) glycoprotein epitope FFL was redesigned based on its complex crystal structure with motavizumab, an mAb drug in development for the prevention of RSV infections, aiming to obtain therapeutic peptide vaccines with high affinity to induce RSV-specific neutralizing antibodies. Computational modeling and analysis found that only a small region covering the helix-turn-helix (HTH) motif of FFL can directly interact with motavizumab and confer stability and specificity to the complex system, while the rest of the epitope primarily serves as a structural scaffold that stabilizes the HTH conformation of motavizumab-binding site. Molecular dynamics simulations revealed a large flexibility and intrinsic disorder for the isolated linear HTH peptide, which would incur a considerable entropy penalty upon binding to motavizumab. In this respect, the FFL epitope was redesigned by truncation, mutation, and cyclization to derive a number of small cyclic peptide immunogens. We also employed in vitro fluorescence-based assays to demonstrate that the linear epitope peptide has no observable affinity to motavizumab, whereas redesigned versions of the peptide can bind with a moderate or high potency. Graphical abstract Computationally modeled complex structure of RSV F glycoprotein with motavizumab and zoom up of the complex binding site.

Short-term association between ambient air pollution and pneumonia in children: A systematic review and meta-analysis of time-series and case-crossover studies

Ambient air pollution has been associated with respiratory diseases in children. However, its effects on pediatric pneumonia have not been meta-analyzed. We conducted a systematic review and meta-analysis of the short-term association between ambient air pollution and hospitalization of children due to pneumonia. We searched the Web of Science and PubMed for indexed publications up to January 2017. Pollutant-specific excess risk percentage (ER%) and confidence intervals (CI) were estimated using random effect models for particulate matter (PM) with diameter ≤ 10 (PM₁₀) and ≤2.5 μm (PM_2.5), sulfur dioxide (SO₂), ozone (O₃), nitrogen dioxide (NO₂), and carbon monoxide (CO). Results were further stratified by subgroups (children under five, emergency visits versus hospital admissions, income level of study location, and exposure period). Seventeen studies were included in the meta-analysis. The ER% per 10 μg/m³ increase of pollutants was 1.5% (95% CI: 0.6%-2.4%) for PM₁₀ and 1.8% (95% CI: 0.5%-3.1%) for PM_2.5. The corresponding values per 10 ppb increment of gaseous pollutants were 2.9% (95% CI: 0.4%-5.3%) for SO₂, 1.7% (95% CI: 0.5%-2.8%) for O₃, and 1.4% (95% CI: 0.4%-2.4%) for NO₂. ER% per 1000 ppb increment of CO was 0.9% (95% CI: 0.0%-1.9%). Associations were not substantially different between subgroups. This meta-analysis shows a positive association between daily levels of ambient air pollution markers and hospitalization of children due to pneumonia. However, lack of studies from low-and middle-income countries limits the quantitative generalizability given that susceptibilities to the adverse effects of air pollution may be different in those populations. The meta-regression in our analysis further demonstrated a strong effect of country income level on heterogeneity.

Lung ultrasound as a diagnostic tool for radiographically-confirmed pneumonia in low resource settings

Background

Pneumonia is a leading cause of morbidity and mortality in children worldwide; however, its diagnosis can be challenging, especially in settings where skilled clinicians or standard imaging are unavailable. We sought to determine the diagnostic accuracy of lung ultrasound when compared to radiographically-confirmed clinical pediatric pneumonia.

Methods

Between January 2012 and September 2013, we consecutively enrolled children aged 2–59 months with primary respiratory complaints at the outpatient clinics, emergency department, and inpatient wards of the Instituto Nacional de Salud del Niño in Lima, Peru. All participants underwent clinical evaluation by a pediatrician and lung ultrasonography by one of three general practitioners. We also consecutively enrolled children without respiratory symptoms. Children with respiratory symptoms had a chest radiograph. We obtained ancillary laboratory testing in a subset.

Results

Final clinical diagnoses included 453 children with pneumonia, 133 with asthma, 103 with bronchiolitis, and 143 with upper respiratory infections. In total, CXR confirmed the diagnosis in 191 (42%) of 453 children with clinical pneumonia. A consolidation on lung ultrasound, which is our primary endpoint for pneumonia, had a sensitivity of 88.5%, specificity of 100%, and an area under-the-curve of 0.94 (95% CI 0.92–0.97) when compared to radiographically-confirmed clinical pneumonia. When any abnormality on lung ultrasound was compared to radiographically-confirmed clinical pneumonia the sensitivity increased to 92.2% and the specificity decreased to 95.2%, with an area under-the-curve of 0.94 (95% CI 0.91–0.96).

Conclusions

Lung ultrasound had high diagnostic accuracy for the diagnosis of radiographically-confirmed pneumonia. Added benefits of lung ultrasound include rapid testing and high inter-rater agreement. Lung ultrasound may serve as an alternative tool for the diagnosis of pediatric pneumonia.

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Lung ultrasound is emerging as a promising imaging alternative for the diagnosis of pneumonia in children.

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Existing studies in children are limited by small sample size, heterogeneity of populations, variable reference standards, and selection bias.

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We found that lung ultrasound can be implemented at a busy healthcare center with high diagnostic accuracy and high inter-rater agreement.

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Lung ultrasound was conducted without major disruptions in workflow, and it took <10 minutes to perform in most instances.

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This is the largest study demonstrating high diagnostic accuracy of lung ultrasound in children for the diagnosis of pneumonia.

Community-acquired pneumonia in children: current challenges and future directions

Pneumonia is a commonly encountered illness and the leading cause of death in children under 5 years of age. Our current management strategies remain less than optimal in part because we do not have adequate tools to determine etiology, classify patients and predict their outcomes. Studies in the last decade have demonstrated that viruses are commonly detected in children with pneumonia, but on many occasions this is not sufficient to establish a clear etiologic diagnosis since bacterial coinfection cannot be excluded. Gene expression profile analysis provides a comprehensive assessment of the host response to infection. Preliminary data suggest that transcriptional profile analysis and measurement of Molecular Distance to Health (MDTH) scores allows more precise patient classification than current diagnostic techniques and laboratory markers. Application of this tool to the evaluation of children with pneumonia may enhance our clinical decision making process and ultimately improve patient outcomes.

Antibiotic availability and the prevalence of pediatric pneumonia during a physicians' strike

BACKGROUND

Antibiotics are widely believed to be overpre-scribed for pediatric respiratory infections, yet there are few data available on the effect of a sudden decrease in antibiotic availability on pediatric infectious disease.

OBJECTIVE

To determine whether the prevalence of radiographically diagnosed pneumonia changed over a period of decreased physician access and decreased antibiotic availability.

DESIGN

A retrospective study was performed which reviewed the number of pediatric respiratory antibiotic prescriptions over a period which included a physicians' strike. The study examined whether antibiotic availability had been affected by the strike. Pediatric chest radiograph reports were reviewed for the same period to determine whether changes in antibiotic availability had affected the prevalence of radiographically diagnosable pneumonias among children presenting to a pediatric emergency room.

RESULTS

While prescriptions for antibiotics fell by a minimum estimate of 28% during the strike, there was no change in the frequency of radiographic diagnoses of pneumonia.

CONCLUSIONS

Respiratory antibiotics appear to be available in the community in excess of the amount required to control pneumonia. A 28% decrease in antibiotic availability did not result in a significant increase in respiratory disease.