Associations between Urinary Mercury/Cadmium Concentrations and Anthropometric Features in Korean Children.

Investigating the impact of urinary mercury and cadmium on anthropometric parameters in Korean children is crucial amid growing concerns about heavy metal exposure and childhood growth. Using data from the Korean National Environmental Health Survey (2015-2017), we assessed age- and sex-specific associations of urinary mercury and cadmium with height and body mass index (BMI) z-scores in 1458 children aged 3-5 (n = 571) and 6-11 years (n = 887). Overall, 5.0% had stunted height (3-5 years: 6.9%, 6-11 years: 3.8%), whereas older children exhibited higher overweight/obesity prevalence (29.2%) than younger ones did (22.2%). In 3-5-year-old boys, urinary mercury correlated negatively with height z-scores (p < 0.001), whereas in girls, urinary cadmium correlated positively (p = 0.015). Boys aged 6-11 years showed positive associations between mercury/cadmium levels and BMI z-scores (p = 0.012). Logistic regression indicated associations between urinary mercury and stunted height likelihood (p = 0.001) and between urinary cadmium and reduced overweight likelihood (p = 0.039) in 3-5-year-old boys. In boys aged 6-11 years, urinary cadmium levels were positively associated with overweight likelihood (p = 0.003). This study underscores the link between elevated urinary mercury, cadmium levels, and growth disruptions in Korean children, emphasizing the need for public health strategies for reducing childhood heavy metal exposure.

Green Solvent Selection for All Solution-Processed Inverted Quantum Dot Light Emitting Diode.

Quantum-dot light-emitting diodes (QD-LEDs) have gained attention as potential display technologies. However, the solvents used to dissolve a polymeric hole transport layer (HTL) are hazardous to both humans and the environment. Additionally, intermixing the HTL and QD layers presents a significant challenge when fabricating inverted QD-LEDs. Here, a green solvent selection procedure to achieve good device performance and environmental safety in QD-LEDs is established. This procedure utilizes Hansen solubility parameters and surface roughness to identify a set of solvents that do not lower the device performance by avoiding interlayer mixing or a rough interface. The CHEM21 solvent selection guide is used to screen for environmentally hazardous solvents. Finally, cyclopentanone (CPO) is selected as the optimal HTL solvent from among 16 candidates. Using CPO improves the maximum luminescence by ≈1.6 times and the maximum current efficiency by ≈12.6 times, compared to that of conventional devices using hazardous chlorobenzene. Solvent selection is critical for the fabrication of green and high-performance inverted QD-LEDs, particularly for large display panels that require n-type oxide thin-film transistors.

Insights from the COCOA birth cohort: The origins of childhood allergic diseases and future perspectives.

The ongoing COhort for Childhood Origin of Asthma and allergic diseases (COCOA) study is a prospective birth cohort investigating the origin and natural courses of childhood allergic diseases, including atopic dermatitis, food allergy, allergic rhinitis and asthma, with long-term prognosis. Initiated under the premise that allergic diseases result from a complex interplay of immune development alterations, environmental exposures, and host susceptibility, the COCOA study explores these dynamic interactions during prenatal and postnatal periods, framed within the hygiene and microbial hypotheses alongside the developmental origins of health and disease (DOHaD) hypothesis. The scope of the COCOA study extends to genetic predispositions, indoor and outdoor environmental variables affecting mothers and their offsprings such as outdoor and indoor air pollution, psychological factors, diets, and the microbiomes of skin, gut, and airway. We have embarked on in-depth investigations of diverse risk factors and the pathophysiological underpinnings of allergic diseases. By employing multi-omics approaches-proteomics, transcriptomics, and metabolomics-we gain deeper insights into the distinct pathophysiological processes across various endotypes of childhood allergic diseases, incorporating the exposome using extensive resources within the COCOA study. Integration with large-scale datasets, such as national health insurance records, enhances robustness and mitigates potential limitations inherent to birth cohort studies. As part of global networks focused on childhood allergic diseases, the COCOA study fosters collaborative research across multiple cohorts. The findings from the COCOA study are instrumental in informing precision medicine strategies for childhood allergic diseases, underpinning the establishment of disease trajectories.

RETRACTED: Choi et al. Validation of the CHA2DS2-VA Score (Excluding Female Sex) in Nonvalvular Atrial Fibrillation Patients: A Nationwide Population-Based Study. J. Clin. Med. 2022, 11, 1823.

The journal retracts the article "Validation of the CHA2DS2-VA Score (Excluding Female Sex) in Nonvalvular Atrial Fibrillation Patients: A Nationwide Population-Based Study" [...].

Photoluminescence enhancement in quantum-dot-polymer films with CO2 micropores through KHCO3 decomposition.

Quantum-dot (QDs) polymer composite films, which are key components in recent display applications, require improved photoluminescence (PL) intensity and color conversion efficiency for better display quality and low power consumption. In this study, we developed a novel approach to improve the photoluminescence (PL) of quantum dot (QDs)-polymer nanocomposite films. This was achieved by incorporating CO2 micropores and scattering particles into QD-embedded photopolymerizable polymer films. CO2 micropores were generated by the decomposition of KHCO3 in the film. The CO2 micropores, along with the partially decomposed KHCO3 microparticles, act as a scattering medium that increases the photon absorbance and improves the PL intensity. The effect of KHCO3 annealing temperature on various optical properties is investigated, and it is found that a large number of uniform micropores are created in the film at an optimal temperature, 110 ℃. Compared to an ordinary QD-polymer film, the PL of the QD-hybrid-foamed polymer film increases by 4.2 times. This method is fast and economically efficient, and provides insights into the design of high-performance optoelectronic devices.

KAAACI Allergic Rhinitis Guidelines: Part 2. Update in Non-pharmacological Management.

Allergic rhinitis is the most common chronic disease worldwide. Various upper airway symptoms lower quality of life, and due to the recurrent symptoms, multiple treatments are usually attempted rather than one definitive treatment. There are alternatives to medical (medication-based) and non-medical treatments. A guideline is needed to understand allergic rhinitis and develop an appropriate treatment plan. We have developed guidelines for medical treatment based on previous reports. The current guidelines herein are associated with the "KAAACI Evidence-Based Guidelines for Allergic Rhinitis in Korea, Part 1: Update in pharmacotherapy" in which we aimed to provide evidence-based recommendations for the medical treatment of allergic rhinitis. Part 2 focuses on non-pharmacological management, including allergen-specific immunotherapy, subcutaneous or sublingual immunotherapy, nasal saline irrigation, environmental management strategies, companion animal management, and nasal turbinate surgery. The evidence to support the treatment efficacy, safety, and selection has been systematically reviewed. However, larger controlled studies are needed to elevate the level of evidence to select rational non-medical therapeutic options for patients with allergic rhinitis.

KAAACI Allergic Rhinitis Guidelines: Part 1. Update in Pharmacotherapy.

The prevalence of allergic rhinitis (AR) and the socioeconomic burden associated with the medical cost and quality of life (QOL) of AR have progressively increased. Therefore, practical guidelines for the appropriate management of AR need to be developed based on scientific evidence while considering the real-world environment, values, and preferences of patients and physicians. The Korean Academy of Asthma, Allergy and Clinical Immunology revised clinical guidelines of AR to address key clinical questions of the management of AR. Part 1 of the revised guideline covers the pharmacological management of patients with AR in Korea. Through a meta-analysis and systematic review, we made 4 recommendations for AR pharmacotherapy, including intranasal corticosteroid (INCS)/intranasal antihistamine (INAH) combination therapy, oral antihistamine/INCS combination therapy, leukotriene receptor antagonist treatment in AR patients with asthma, and prophylactic treatment for patients with pollen-induced AR. However, all recommendations are conditional because of the low or very low evidence of certainty. Well-designed and strictly executed randomized controlled trials are needed to measure and report appropriate outcomes.

Clinical characteristics of pediatric patients infected with SARS-CoV-2 versus common human coronaviruses: a national multicenter study.

BACKGROUND: Human coronaviruses (HCoV) cause mild upper respiratory infections; however, in 2019, a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged, causing an acute respiratory disease pandemic. Coronaviruses exhibit marked epidemiological and clinical differences. PURPOSE: This study compared the clinical, laboratory, and radiographic findings of children infected with SARS-CoV-2 versus HCoV. METHODS: SARS-CoV-2 data were obtained from the Korea Disease Control and Prevention Agency (KDCA) registry and 4 dedicated coronavirus disease 2019 (COVID-19) hospitals. Medical records of children admitted with a single HCoV infection from January 2015 to March 2020 were collected from 10 secondary/tertiary hospitals. Clinical data included age, sex, underlying disease, symptoms, test results, imaging findings, treatment, and length of hospital stay. RESULTS: We compared the clinical characteristics of children infected with HCoV (n=475) to those of children infected with SARS-CoV-2 (272 from KDCA, 218 from COVID-19 hospitals). HCoV patients were younger than KDCA patients (older than 9 years:3.6% vs. 75.7%; P<0.001) and patients at COVID-19 hospitals (2.0±2.9 vs 11.3±5.3; P<0.001). Patients with SARS-CoV-2 infection had a lower rate of fever (26.6% vs. 66.7%; P<0.001) and fewer respiratory symptoms than those with HCoV infection. Clinical severity, as determined by oxygen therapy and medication usage, was worse in children with HCoV infection. Children and adolescents with SARS-CoV-2 had less severe symptoms. CONCLUSION: Children and adolescents with COVID-19 had a milder clinical course and less severe disease than those with HCoV in terms of symptoms at admission, examination findings, and laboratory and radiology results.

Prenatal maternal anxiety promotes atopic dermatitis in offspring via placental DNA methylation changes.

BACKGROUND: Maternal anxiety during pregnancy has been previously reported to be associated with atopic dermatitis (AD) in offspring. The potential mechanism is not yet proven but epigenetic change may be suggested. OBJECTIVE: We examined whether maternal anxiety during pregnancy may alter placental DNA methylation, then develop AD in the offspring. METHODS: We evaluated maternal anxiety at 36 weeks of gestation by self-reported questionnaires, the State-Trait Anxiety Inventory-Trait subscale (STAI-T), in the Cohort for Childhood Origin of Asthma and Allergic Diseases (COCOA) study. AD was diagnosed at 6 months of age by pediatric allergists. We stratified the subjects into four groups according to the STAI score of mothers and diagnosis of AD in children. Placental genome-wide methylation microarray was analyzed using Infinium 450K BeadChip and selected genes were validated by pyrosequencing. RESULTS: From microarray, several differential methylation sites were identified in AD and healthy subjects and in total subjects, regarding to the STAI scores. Among differential methylation sites in microarray, six sites were selected for pyrosequencing. And site of matrix metalloproteinases 27 (MMP27) among 6 sites showed decreased methylation in AD infants with high STAI mothers compared to healthy infants with low STAI mothers. CONCLUSIONS: Epigenetic change in placenta can be a suggesting mechanism for the development of AD in offspring at 6 months of age associated with maternal anxiety during pregnancy and MMP27 may be a candidate gene.

Particulate matter exposure during pregnancy increases risk of childhood asthma: modified by gender and NRF2 genotype.

BACKGROUND: Exposure to particulate matter (PM) has been known to develop asthma in children and the oxidative stress-related mechanisms are suggested. For the development of asthma, not only the exposure dose but also the critical window and the risk modifying factors should be evaluated. OBJECTIVE: We investigated whether prenatal exposure to PM10 increases the risk of childhood asthma and evaluated the modifying factors, such as gender and reactive oxidative stress-related gene. METHODS: A general population-based birth cohort, the Panel Study of Korean Children (PSKC), including 1572 mother-baby dyads was analyzed. Children were defined to have asthma at age 7 when a parent reported physician-diagnosed asthma. Exposure to PM10 during pregnancy was estimated by land-use regression models based on national monitoring system. TaqMan method was used for genotyping nuclear factor, erythroid 2-related factor, NRF2 (rs6726395). A logistic Bayesian distributed lag interaction model (BDLIM) was used to evaluate the associations between prenatal PM10 exposure and childhood asthma by gender and NRF2. RESULTS: Exposure to PM10 during pregnancy was associated with the development of asthma (aOR 1.03, 95% CI 1.001.06). Stratifying by gender and NRF2 genotype, exposure to PM10 during 26-28 weeks gestation increased the risk of childhood asthma, especially in boys with NRF2 GG genotype. CONCLUSIONS: A critical window for PM10 exposure on the development of childhood asthma was during 26-28 weeks of gestation, and this was modified by gender and NRF2 genotype.

Assessment of variables associated with prolonged admission duration in children with Mycoplasma pneumoniae pneumonia.

INTRODUCTION: Macrolide-resistant Mycoplasma pneumoniae (MRMP) has become prevalent in children. This study investigated the clinical and laboratory variables of MRMP and macrolide-sensitive M. pneumoniae (MSMP) and identified factors associated with prolonged hospital admission in children. METHODS: A prospective multicenter study was conducted in 1063 children <18 years old in July 2018-June 2020. The 454 had a positive M. pneumoniae polymerase chain reaction assay. RESULTS: Most subjects had MRMP (78.4%), and all mutated strains had the A2063G transition. We defined MRMP* (n = 285) as MRMP pneumonia requiring admission and MSMP* (n = 72) as MSMP pneumonia requiring admission. Patients with MRMP pneumonia were older, more likely to have segmental/lobar pneumonia, and had more febrile days than those with MSMP pneumonia. C-reactive protein (CRP), lactate dehydrogenase (LDH), and percentage neutrophils were more strongly associated with MRMP* than MSMP* groups. Percentage neutrophils, CRP, and alanine aminotransferase significantly changed between admission and follow-up measurements in patients with MRMP* (P < 0.05). The duration of admission positively correlated with the number of febrile days after initiation of antibiotic medication and laboratory variables (white blood cell count, CRP, and aspartate aminotransferase [AST]) (P < 0.05). Random forest analysis indicated that the number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission was over five. CONCLUSIONS: This study indicated that children with M. pneumoniae pneumonia with a higher number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission were more likely to have prolonged admission duration.

Effectiveness and safety of electroacupuncture and its cotreatment with electronic moxibustion in the treatment of patients with moderate benign prostatic hyperplasia using alpha blocker: An assessor-blinded, randomized, controlled pilot study.

BACKGROUND: Benign prostatic hyperplasia (BPH) is a disease that affects the quality of life by causing lower urinary tract symptoms (LUTS) in men. Electroacupuncture (EA) and moxibustion therapy have been suggested as an adjunct therapy for improving LUTS in patients with BPH, but clinical studies evaluating the effectiveness of EA and its cotreatment with electronic moxibustion (EM) in patients who have been prescribed alpha blockers have yet to be reported. Therefore, this study aimed to evaluate the effectiveness and safety of EA and EM. METHODS: Twenty-eight patients diagnosed with BPH were randomized to treatment group (TG, n = 14) or control group (CG, n = 14). The TG continued to use the previously prescribed alpha blocker and received the cotreatment of EA and EM 3 times a week for 6 weeks. The CG continued to use the previously prescribed alpha blocker alone for 6 weeks. The primary outcome was the mean change in the international prostate symptom score (IPSS) from baseline to week 6. The secondary outcomes were IPSS at week 3 and 12, clinical relevance, IPSS life satisfaction, EuroQol-Five dimensions, average urinary flow rate, maximum urinary flow rate, and prostate volume. RESULTS: The IPSS decreased at all time points with a statistically significant difference between the 2 groups (3W: P = .0313; 6W: P = .0010; 12W: P = .0304). Based on the minimal clinically important difference (MCID, 3 points), there were significant differences between the TG and the CG at week 3, 6, and 12 (3W: P = .0461; 6W: P = .0123; 12W: P = .0216). Significant group × week interaction effects were found for the IPSS score (P = .0018), as determined from analyses using repeated measures analysis of variance. There were no significant differences between the 2 groups in IPSS life satisfaction, EuroQol-Five dimensions, average urinary flow rate, maximum urinary flow rate, and prostate volume. CONCLUSION: EA and its cotreatment with EM might have a beneficial effect as an adjunct therapy in improving LUTS in patients with BPH. Large-scale randomized controlled trials are warranted to confirm the effectiveness and safety of EA and its cotreatment with EM.

Analysis of national surveillance of respiratory pathogens for community-acquired pneumonia in children and adolescents.

BACKGROUND: Respiratory infections among children, particularly community-acquired pneumonia (CAP), is a major disease with a high frequency among outpatient and inpatient visits. The causes of CAP vary depending on individual susceptibility, the epidemiological characteristics of the community, and the season. We performed this study to establish a nationwide surveillance network system and identify the causative agents for CAP and antibiotic resistance in Korean children with CAP. METHODS: The monitoring network was composed of 28 secondary and tertiary medical institutions. Upper and lower respiratory samples were assayed using a culture or polymerase chain reaction (PCR) from August 2018 to May 2020. RESULTS: A total of 1023 cases were registered in patients with CAP, and PCR of atypical pneumonia pathogens revealed 422 cases of M. pneumoniae (41.3%). Respiratory viruses showed a positivity rate of 65.7% by multiplex PCR test, and human rhinovirus was the most common virus, with 312 cases (30.5%). Two hundred sixty four cases (25.8%) were isolated by culture, including 131 cases of S. aureus (12.8%), 92 cases of S. pneumoniae (9%), and 20 cases of H. influenzae (2%). The cultured, isolated bacteria may be colonized pathogen. The proportion of co-detection was 49.2%. The rate of antibiotic resistance showed similar results as previous reports. CONCLUSIONS: This study will identify the pathogens that cause respiratory infections and analyze the current status of antibiotic resistance to provide scientific evidence for management policies of domestic respiratory infections. Additionally, in preparation for new epidemics, including COVID-19, monitoring respiratory infections in children and adolescents has become more important, and research on this topic should be continuously conducted in the future.

Validation of the CHA2DS2-VA Score (Excluding Female Sex) in Nonvalvular Atrial Fibrillation Patients: A Nationwide Population-Based Study.

Sex (i.e., female sex) confers one point for the CHA2DS2-VASc score. For this reason, females with atrial fibrillation (AF) always have a CHA2DS2-VASc score of at least 1. To compare the CHA2DS2-VA (excluding female sex) and CHA2DS2-VASc scores in Korean AF patients using the Korean National Health Insurance Service database, we analyzed the risk of ischemic stroke in nonvalvular AF patients between 2013 and 2017. The predictive values of the CHA2DS2-VA and CHA2DS2-VASc scores for ischemic stroke were evaluated using the C-statistic and net reclassification improvement (NRI). The primary outcome was the occurrence of ischemic stroke. A total of 185,637 patients with AF (49.7% women) were included in this study. The mean ages were 66.5 years for females and 64.9 years for males. The incidence of ischemic stroke in male patients was similar to females (3.63%/year vs. 3.72%/year, p = 0.273, respectively). In addition, no sex difference was apparent for stroke risk in AF patients stratified by risk factor component and age group. In the C-statistic analysis, the predictive ability of the CHA2DS2-VA score for ischemic stroke was similar to the CHA2DS2-VASc score. Additionally, CHA2DS2-VA performed better for predicting ischemic stroke in AF patients with risk scores of ≥2 (AUC 0.701 vs. 0.689, z = 4.596, p < 0.001) or those aged ≥75 years (AUC 0.715 vs. 0.701, z = 4.957, p < 0.001). In Korean AF patients, female sex is not a specific risk factor that contributes to the development of ischemic stroke. The CHA2DS2-VA score, which excludes female sex, may be a more suitable risk score for guiding anticoagulation decisions in Korean AF patients.

Weigela florida inhibits the expression of inflammatory mediators induced by Pseudomonas aeruginosa and Staphylococcus aureus infection.

Inflammatory responses involve the action of inflammatory mediators that are necessary for the clearance of invading bacterial pathogens. However, excessive production of inflammatory mediators can damage tissues, thereby impairing bacterial clearance. Here, we examined the effects of Weigela florida on the expression of inflammatory cytokines induced by Pseudomonas aeruginosa or Staphylococcus aureus infection in macrophages. The results showed that pre-treatment with W. florida markedly downregulated the bacterial infection-mediated expression of cytokines. Additionally, post-treatment also triggered anti-inflammatory effects in cells infected with S. aureus to a greater extent than in those infected with P. aeruginosa. Bacterial infection activated inflammation-associated AKT (Thr308 and Ser473)/NF-κB and MAPK (p38, JNK, and ERK) signaling pathways, whereas W. florida treatment typically inhibited the phosphorylation of AKT/NF-κB and p38/JNK, supporting the anti-inflammatory effects of W. florida. The present results suggest that W. florida decreases the infection-mediated expression of inflammatory mediators by inhibiting the AKT/NF-κB and MAPK signaling pathways, implying that it may have potential use as an inhibitory agent of excessive inflammatory responses.

Clinical Characteristics of Macrolide-Refractory Mycoplasma pneumoniae Pneumonia in Korean Children: A Multicenter Retrospective Study.

Mycoplasma pneumoniae is a major causative pathogen of community-acquired pneumonia in children, and the treatment of choice is macrolides. There is an increasing trend in reports of refractory clinical responses despite macrolide treatment due to the emergence of macrolide-resistant M. pneumoniae. Early discrimination of macrolide-refractory M. pneumoniae pneumonia (MrMP) from macrolide-sensitive M. pneumoniae pneumonia (MSMP) is vital; however, testing for macrolide susceptibility at the time of admission is not feasible. This study aimed to identify the characteristics of MrMP in Korean children, in comparison with those of MSMP. In this multicenter study, board-certified pediatric pulmonologists at 22 tertiary hospitals reviewed the medical records from 2010 to 2015 of 5294 children who were hospitalized with M. pneumoniae pneumonia and administered macrolides as the initial treatment. One-way analysis of variance and the Kruskal-Wallis test were used to compare differences between groups. Of 5294 patients (mean age, 5.6 years) included in this analysis, 240 (4.5%), 925 (17.5%), and 4129 (78.0%) had MrMP, macrolide-less effective M. pneumoniae pneumonia, and MSMP, respectively. Compared with the MSMP group, the MrMP group had a longer fever duration, overall (13.0 days) and after macrolide use (8.0 days). A higher proportion of MrMP patients had respiratory distress, pleural effusion, and lobar pneumonia. The mean aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and C-reactive protein levels were the highest in the MrMP group, along with higher incidences of extrapulmonary manifestations and atelectasis (during and post infection). Pre-existing conditions were present in 17.4% (n = 725/4159) of patients, with asthma being the most common (n = 334/4811, 6.9%). This study verified that MrMP patients show more severe initial radiographic findings and clinical courses than MSMP patients. MrMP should be promptly managed by agents other than macrolides.

Mid-pregnancy PM2.5 exposure affects sex-specific growth trajectories via ARRDC3 methylation.

Prenatal particulate matter <2.5 µm (PM2.5) is associated with adverse birth growth. However, the longitudinal growth impacts have been little studied, and no mechanistic relationships have been described. We investigated the association between prenatal PM2.5 exposure and growth trajectories, and the possible role of epigenetics. We enrolled 1313 neonates with PM2.5 data measured by ordinary kriging from the COhort for Childhood Origin of Asthma and allergic diseases, followed up at 1, 3, and 5 years to evaluate growth. Differential DNA methylation and pyrosequencing of cord blood leukocytes was evaluated according to the prenatal PM2.5 levels and birth weight (BW). PM2.5 exposure during the second trimester (T2) caused the lowest BW in both sexes, further adjusted for indoor PM2.5 levels [female, aOR 1.39 (95% CI 1.05-1.83); male, aOR 1.36 (95% CI 1.04-1.79)]. Bayesian distributed lag models with indoor PM2.5 adjustments revealed a sensitive window for BW effects at 10-26 weeks gestation, but only in females. Latent class mixture models indicated that a persistently low weight-for-height percentile trajectory was more prevalent in the highest PM2.5 exposure quartile at T2 in females, compared to a persistently high trajectory (36.5% vs. 20.3%, P = 0.022). Also, in the females only, the high PM2.5 and low BW neonates showed significantly greater ARRDC3 methylation changes. ARRDC3 methylation was also higher only in females with low weight at 5 years of age. Higher fetal PM2.5 exposure during T2 may cause a decreased growth trajectory, especially in females, mediated by ARRDC3 hyper-methylation-associated energy metabolism.

Prenatal PM2.5 exposure and vitamin D-associated early persistent atopic dermatitis via placental methylation.

BACKGROUND: The effects of prenatal particulate matter with an aerodynamic diameter ranging from 0.1 µm to 2.5 µm (PM2.5) and vitamin D on atopic dermatitis (AD) phenotypes have not been evaluated. DNA methylation and cord blood (CB) vitamin D could represent a plausible link between prenatal PM2.5 exposure and AD in an offspring. OBJECTIVE: To determine the critical windows of prenatal PM2.5 exposure on the AD phenotypes, if vitamin D modulated these effects, and if placental DNA methylation mediated these effects on AD in offspring. METHODS: Mother-child pairs were enrolled from the birth cohort of the Cohort for Childhood Origin of Asthma and allergic diseases (COCOA) study. PM2.5 was estimated by land-use regression models, and CB vitamin D was measured by chemiluminescence immunoassay. AD was identified by the parental report of a physician's diagnosis. We defined the following 4 AD phenotypes according to onset age (by the age of 2 years) and persistence (by the age of 3 years): early-onset transient and persistent, late onset, and never. Logistic regression analysis and Bayesian distributed lag interaction model were used. DNA methylation microarray was analyzed using an Infinium Human Methylation EPIC BeadChip (Illumina, San Diego, California) in placenta. RESULTS: PM2.5 exposure during the first trimester of pregnancy, especially during 6 to 7 weeks of gestation, was associated with early-onset persistent AD. This effect increased in children with low CB vitamin D, especially in those with PM2.5 exposure during 3 to 7 weeks of gestation. AHRR (cg16371648), DPP10 (cg19211931), and HLADRB1 (cg10632894) were hypomethylated in children with AD with high PM2.5 and low CB vitamin D. CONCLUSION: Higher PM2.5 during the first trimester of pregnancy and low CB vitamin D affected early-onset persistent AD, and the most sensitive window was 6 to 7 weeks of gestation. Placental DNA methylation mediated this effect.

Is it necessary to evaluate urinary tract infection in children with lower respiratory tract infection?

AIM: Although the incidence of urinary tract infection (UTI) in children with lower respiratory tract infection (LRTI) has been reported as 3.1-10.0%, the exact concomitant prevalence is questionable. Here, we evaluated the prevalence and related risk factors of UTI associated with LRTI in children under 36 months of age. METHODS: We retrospectively reviewed the medical charts of 1574 patients under 36 months of age who were hospitalised with LRTI from January 2017 to December 2019 in a single centre, Seoul, South Korea. Among them, we analysed 278 patients who showed fever and performed urine evaluation. Urine was collected by catheterisation in children under 24 months of age and by voided urine between 24 and 36 months of age. RESULTS: The prevalence of concomitant UTI and LRTI was 13.6% in children under 24 months of age. Mean age was significantly younger in the UTI versus non-UTI group (6.93 ± 7.26 months vs. 12.61 ± 11.70 months; P < 0.001). When the participants were stratified by age, the prevalence of UTI was significantly higher in children younger than 24 months of age compared to older ones (P = 0.006). UTIs were more prevalent in boys than in girls (14.6% vs. 5.8%, P = 0.018). Peak body temperature, fever duration, premature birth and detected respiratory virus type did not differ between groups. CONCLUSIONS: It is not uncommon for children with LRTI with fever to be accompanied by UTI. When evaluating for UTI in children with febrile LRTI, age and sex must be considered.