Sex, Age, and Species Differences of Perfluorooctanoic Acid Modeled by Flow- versus Permeability-limited Physiologically-Based Pharmacokinetic Models.

This study aimed to investigate sex, age, and species differences of perfluorooctanoic acid (PFOA) using physiologically-based pharmacokinetic (PBPK) models in rats and humans. PBPK models were generally developed as either flow- or permeability-limited models. The flow-limited model is cost-effective and allows for human PK prediction through simple allometric scaling, while the permeability-limited model can incorporate detailed information on the disposition process through in vitro-in vivo extrapolation (IVIVE). PFOA was administered via oral or intravenous administration with 5mg/kg in male and female rats of different ages and the data was used to develop the PBPK models. Our results showed that both models successfully captured sex differences in rats, while only the flow-limited model with male rats and the permeability-limited model with both male and female rats provided comparable predictions in the human clinical study. More than the flow-limited model, the permeability-limited model effectively explained sex differences in rats and species differences through IVIVE. Additionally, the ontogeny-based mechanistic description of PFOA disposition enabled the interpretation of age- and sex-dependent pharmacokinetics. Although the flow-limited PBPK model lacked mechanistic interpretability compared to the permeability-limited model, it demonstrated reliable human prediction through simple allometric scaling. In conclusion, the permeability PBPK model could interpret age, sex, and species differences and it could improve the accuracy of human prediction.

Inflachromene ameliorates Parkinson's disease by targeting Nrf2-binding Keap1.

Parkinson's disease (PD) is the most common neurodegenerative disease characterized by movement disorder. Despite current therapeutic efforts, PD progression and the loss of dopaminergic neurons in the substantia nigra remain challenging to prevent due to the complex and unclear molecular mechanism involved. We adopted a phenotype-based drug screening approach with neuronal cells to overcome these limitations. In this study, we successfully identified a small molecule with a promising therapeutic effect for PD treatment, called inflachromene (ICM), through our phenotypic screening strategy. Subsequent target identification using fluorescence difference in two-dimensional gel electrophoresis (FITGE) revealed that ICM ameliorates PD by targeting a specific form of Keap1. This interaction led to upregulating various antioxidants, including HO-1, NQO1, and glutathione, ultimately alleviating PD symptoms. Furthermore, ICM exhibited remarkable efficacy in inhibiting the loss of dopaminergic neurons and the activation of astrocytes and microglia, which are critical factors in PD pathology. Our findings suggest that the phenotypic approach employed in this study identified that ICM has potential for PD treatment, offering new hope for more effective therapeutic interventions in the future.

Trends in Incidence and Drug Prescriptions for Croup in Children Under 5 Years of Age: A 2002-2019 Population-Based Study.

BACKGROUND: Tracking national croup trends can provide important insights for childhood health management. This study aimed to analyze the incidence and drug prescription trends in Korean children over a two-decade period. METHODS: This population-based study encompassed 479,783 children aged < 5 years from 2002-2019, utilizing the National Health Insurance Service-National Sample Cohort. We identified participants with a primary croup diagnosis who were admitted to or visited the emergency room. Age-specific and age-adjusted incidence rates/10,000 person-years were calculated. We assessed using orthogonal polynomial contrasts and stratified by various factors (sex, age, residential area, economic status, comorbidities, and healthcare facility types). We observed changes in the use of five medications: inhaled steroids, systemic steroids, inhaled epinephrine, antibiotics, and short-acting bronchodilators. Generalized binomial logistic regression was used to analyze factors influencing prescription strategies. RESULTS: In 2002, the croup-related visits were 16.1/10,000 person-years, increasing to 98.3 in 2019 (P for trend < 0.001). This trend persisted, regardless of age, sex, region, and economic status. Children with comorbid atopic dermatitis or asthma maintained consistent croup rates, while those without comorbidities increased. Treatment trends showed decreasing antibiotic (73-47%) and oxygen use (21.3-3.4%), with increasing nebulized epinephrine (9.3-41.5%) and multiple drug prescriptions (67.8-80.3%). Primary care centers exhibited a greater increase in prescription usage and hospitalization duration than did tertiary healthcare institutions. CONCLUSION: Over the past two decades, croup incidence has risen, accompanied by increased epinephrine use and decreased antibiotic prescriptions. Longer hospitalization and higher medication use were mainly observed in primary care facilities.

Phase patterning of liquid crystal elastomers by laser-induced dynamic crosslinking.

Liquid crystal elastomers hold promise in various fields due to their reversible transition of mechanical and optical properties across distinct phases. However, the lack of local phase patterning techniques and irreversible phase programming has hindered their broad implementation. Here we introduce laser-induced dynamic crosslinking, which leverages the precision and control offered by laser technology to achieve high-resolution multilevel patterning and transmittance modulation. Incorporation of allyl sulfide groups enables adaptive liquid crystal elastomers that can be reconfigured into desired phases or complex patterns. Laser-induced dynamic crosslinking is compatible with existing processing methods and allows the generation of thermo- and strain-responsive patterns that include isotropic, polydomain and monodomain phases within a single liquid crystal elastomer film. We show temporary information encryption at body temperature, expanding the functionality of liquid crystal elastomer devices in wearable applications.

Machine learning and radiomics for segmentation and classification of adnexal masses on ultrasound.

Ultrasound-based models exist to support the classification of adnexal masses but are subjective and rely upon ultrasound expertise. We aimed to develop an end-to-end machine learning (ML) model capable of automating the classification of adnexal masses. In this retrospective study, transvaginal ultrasound scan images with linked diagnoses (ultrasound subjective assessment or histology) were extracted and segmented from Imperial College Healthcare, UK (ICH development dataset; n = 577 masses; 1444 images) and Morgagni-Pierantoni Hospital, Italy (MPH external dataset; n = 184 masses; 476 images). A segmentation and classification model was developed using convolutional neural networks and traditional radiomics features. Dice surface coefficient (DICE) was used to measure segmentation performance and area under the ROC curve (AUC), F1-score and recall for classification performance. The ICH and MPH datasets had a median age of 45 (IQR 35-60) and 48 (IQR 38-57) years old and consisted of 23.1% and 31.5% malignant cases, respectively. The best segmentation model achieved a DICE score of 0.85 ± 0.01, 0.88 ± 0.01 and 0.85 ± 0.01 in the ICH training, ICH validation and MPH test sets. The best classification model achieved a recall of 1.00 and F1-score of 0.88 (AUC:0.93), 0.94 (AUC:0.89) and 0.83 (AUC:0.90) in the ICH training, ICH validation and MPH test sets, respectively. We have developed an end-to-end radiomics-based model capable of adnexal mass segmentation and classification, with a comparable predictive performance (AUC 0.90) to the published performance of expert subjective assessment (gold standard), and current risk models. Further prospective evaluation of the classification performance of this ML model against existing methods is required.

Correlations between ADL in patients with SCI and caregiver burden, quality of life, and presenteeism in South Korea.

The correlations between activities of daily living (ADL) among patients with spinal cord injury (SCI) and their caregivers' burden, quality of life (QoL), and presenteeism was investigated. Participants included outpatients and inpatients with SCI at a rehabilitation center and their caregivers, recruited between March 2020 and April 2021. Eighty-seven valid responses were analysed using independent t-tests and Pearson's correlations. There was a difference in caregiver burden according to patients' ADL performance. QoL was negatively correlated with caregiver burden and presenteeism. Caregiver burden and presenteeism were positively correlated. Social support can improve caregivers' QoL and reduce caregiver burden and presenteeism-induced work impairment.

Robotic sacrocolpopexy.

Pelvic organ prolapse (POP) is a common cause of gynecological disease in elderly women. The prevalence of POP has increased with an aging society. Abdominal sacrocolpopexy (ASC) is safer and more effective than the vaginal approach in patients with apical compartment POP because it has a higher anatomical cure rate, a lower recurrence rate, less dyspareunia, and improved sexual function. Laparoscopic sacrocolpopexy (LSC) has replaced ASC. Robotic sacrocolpopexy (RSC) also helps overcome the challenges of LSC by facilitating deep pelvic dissection and multiple intracorporeal suturing. The RSC is technically easy to apply, has a steep learning curve, and offers many advantages over the LSC. However, insufficient data led us to conclude that the LSC is superior overall, especially in terms of costeffectiveness. The present review provides insights into different aspects of RSC, highlighting the most common benefits and concerns of this procedure. We searched for eligible articles discussing this issue from January 2019 to March 2022 to reveal the outcomes of RSC.

Associations of personal urinary volatile organic compounds and lung function in children.

BACKGROUND: We investigated the correlation between urine VOC metabolites and airway function in children exposed to anthropogenic volatile organic compounds (VOCs), notable pollutants impacting respiratory health. METHODS: Out of 157 respondents, 141 completed skin prick tests, spirometry, IOS, and provided urine samples following the International Study of Asthma and Allergies in Childhood (ISAAC)-related questions. Allergic sensitization was assessed through skin prick tests, and airway functions were evaluated using spirometry and impulse oscillometry (IOS). Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) was recorded and FEV1/FVC ratio was calculated. Airway mechanics parameters including respiratory resistance at 5 Hz (Rrs5) mean respiratory resistance between 5 Hz and 20 Hz (Rrs5-20), were also recorded. Urine concentrations of metabolites of benzene, ethylbenzene, toluene, xylene, styrene, formaldehyde, carbon-disulfide were analyzed by gas chromatography/tandem mass spectroscopy. RESULTS: The median age at study participation was 7.1 (SD 0.3) years. Muconic acid (benzene metabolites) and o-methyl-hippuric acid (xylene metabolites) above medians were associated with a significant increase in Rrs5 (muconic acid: aß = 0.150, p = .002; o-methyl-hippuric acid: aß = 0.143, p = .023) and a decrease in FEV1/FVC (o-methyl-hippuric acid: aß = 0.054, p = .028) compared to those below median. No associations were observed for Rrs5-20 and FEV1 between the groups categorized as above and below the median (all parameter p values > .05). CONCLUSIONS: Elevated levels of benzene and xylene metabolites were associated with a significant increase in Rrs5 and a decrease in FEV1/FVC, related to increased resistance and restrictive lung conditions compared to individuals with concentrations below the median.

Neurodevelopment in Term Infants with Normal Birthweight following Postnatal Systemic Steroid Exposure.

BACKGROUND: Studies investigating the potential impact of systemic steroid exposure during early infancy on neurological development in full-term infants with normal birth weight are lacking. METHODS: This population-based administrative cohort study used data of national health insurance and a health-screening program for infants and children and included full-term infants who were born in Korea between 2008 and 2012 with normal birth weight and did not have any specific perinatal or neurodevelopmental diseases. The prescription of systemic steroids within the first 3 months of age was mainly considered. The neurological development of children was assessed using the Korean Development Screening Test (K-DST) at 6 years of age. To balance the baseline characteristics of the control and exposed groups, stabilized Inverse Probability of Treatment Weighting with trimming was performed in the main cohort. Ordinal logistic regression was used to assess the association between systemic steroid exposure and unfavorable results in the K-DST. RESULTS: The control and exposure groups had 246,168 and 5,083 children, respectively. The K-DST suggested unfavorable results in 8.1% and 8.6% children in the control and exposure groups, respectively (weighted odds ratio [OR], 95% confidence interval [CI], 1.03, 0.93 - 1.14). When each domain of the K-DST was considered separately, the risk of unfavorable results in the exposed group was not significantly different from that in the control group. CONCLUSIONS: No significant association was observed between exposure to systemic steroids during early infancy and neurodevelopmental impairment at 6 years of age.

The KAAACI Guidelines for Sublingual Immunotherapy.

Allergen immunotherapy is regarded as the only disease-modifying treatment option for various allergic conditions, including allergic rhinitis and asthma. Among the routes of administration of allergens, sublingual immunotherapy (SLIT) has gained clinical interest recently, and the prescription of SLIT is increasing among patients with allergies. After 30 years of SLIT use, numerous pieces of evidence supporting its efficacy, safety, and mechanism allows SLIT to be considered as an alternative option to subcutaneous immunotherapy. Based on the progressive development of SLIT, the current guideline from the Korean Academy of Asthma, Allergy, and Clinical Immunology aims to provide an expert opinion by allergy, pediatrics, and otorhinolaryngology specialists with an extensive literature review. This guideline addresses the use of SLIT, including 1) mechanisms of action, 2) appropriate patient selection for SLIT, 3) the currently available SLIT products in Korea, and 4) updated information on its efficacy and safety. This guideline will facilitate a better understanding of practical considerations for SLIT.

Unraveling the link between atopic dermatitis and autoimmune diseases in children: Insights from a large-scale cohort study with 15-year follow-up and shared gene ontology analysis.

BACKGROUND: Atopic dermatitis and autoimmune diseases are highly heritable conditions that may co-occur from an early age. METHODS: The primary study is a national administrative cohort study involving 499,428 children born in 2002, tracked until 2017. Atopic dermatitis was defined as five or more principal diagnoses of atopic dermatitis and two or more topical steroid prescriptions. We estimated the risks for the occurrence of 41 autoimmune diseases, controlling for risk factors. In addition, we sourced a gene library from the National Library of Medicine to conduct a comprehensive gene ontology. We used Gene Weaver to identify gene set similarity and clustering, and used GeneMania to generate a network for shared genes. RESULTS: Exposed and unexposed groups included 39,832 and 159,328 children, respectively. During a mean follow-up of 12 years, the exposed group had an increased risk of autoimmune disease (hazard ratio, 1.27 [95 % confidence interval, 1.23-1.32]) compared to the unexposed group. The hazard ratios of autoimmune illnesses consistently increased with two- and five years lag times and alternative atopic dermatitis definitions. Shared genes between atopic dermatitis and autoimmune diseases were associated with comorbidities such as asthma, bronchiolitis, and specific infections. Genetic interactions of these shared genes revealed clustering in Th1, Th2, Th17, and non-classifiable pathways. CONCLUSIONS: Atopic dermatitis was significantly associated with an increased risk of subsequent autoimmune disease. we identified the genetically associated disease in atopic dermatitis patients comorbid with autoimmune disease and demonstrated a genetic network between atopic dermatitis and autoimmune diseases.

Repeated measurements and mixture effects of urinary bisphenols, parabens, polycyclic aromatic hydrocarbons, and other chemicals on biomarkers of oxidative stress in pre- and postpartum women.

The association between oxidative stress and exposure to bisphenols, parabens, phenols, polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOCs) has been investigated by many in vitro and in vivo studies. However, most of these findings are based on cross-sectional studies, as a result of which the combined effects of these compounds have been rarely analyzed. In this study, our objective was to assess urinary bisphenols, parabens, PAHs, and VOCs, in relation to oxidative stress during pre-and postpartum periods, analyze the association between these chemicals and oxidative stress via repeated measurements using a linear mixed model (LMM), and evaluate the combined effects exerted by these chemicals on oxidative stress using Bayesian Kernel Machine Regression (BKMR). A total 529 urine samples were collected from 242 pregnant women during the 1st and 2nd trimesters, as well as postpartum follow-ups. Three bisphenols, four parabens, benzopheone-3 (BP-3), triclosan (TCS), four PAHs, two VOCs, and 3- phenoxy-benzoic acid (3-PBA) were analyzed. We also measured 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA), which serve as oxidative stress biomarkers in maternal urine samples. During this period, 8-OHdG decreased steadily, whereas MDA increased during pregnancy and decreased after childbirth. LMM indicated that Bisphenol A, Prophyl-paraben, BP-3, and 1-hydroxypyrene (1-OHP) showed a significant association with increased MDA levels. The BKMR models revealed that the mixture effect exerted by these 16 chemicals had changed MDA levels, which indicate oxidative stress, and that both Butyl Paraben (BP) and 1-hydroxypyrene (1-OHP) had contributed to such oxidative stress. Mixtures of each subgroup (bisphenols, parabens, and PAHs) were associated with increased MDA levels. These findings suggest that exposure to some phenols and PAHs during pre- and post-partum stages may cause oxidative stress, and that exposure to these chemicals should be minimized during this period.

The public perspective on renewable energy versus nuclear power for carbon neutrality in South Korea.

South Korea has legislated "2050 carbon neutrality" in 2021 and is currently implementing it, and debate is brewing over which to focus on as the main means of achieving it in the power generation sector: renewable energy (RE) or nuclear power (NP). This article aims to collect and analyze data on the public preference for RE versus NP. In a national survey of 1000 people, respondents were first asked which was preferred, RE or NP, and then asked to indicate the preference intensity along a 5-point scale. Of all the respondents, 60.3% preferred RE and 27.7% preferred NP. The preference for the former was about 2.2 times more than that for the latter. However, the intensity of the preference for NP was 1.3 times more than that for RE. Both the two-limit Tobit model and ordered probit model have been applied to analyzing the factors influencing the preference. The effects of some variables on the preference for RE over NP are explained, and implications from this are discussed. The findings can be used as a reference to determine the main means of implementation of carbon neutrality or to increase the public acceptance of the specified means.

Reconstruction of circumferential fingertip defect using free superficial palmar branch of the radial artery flap: Report of two cases.

Wide local excision of noninvasive malignant melanomas has been increasingly performed instead of digit amputation, which often results in extensive fingertip defects. Owing to the unique anatomical characteristics of the fingertips, achieving favorable outcomes in both function and cosmesis is challenging during reconstruction. The free superficial palmar branch of the radial artery (SPBRA) flap is advantageous for finger reconstruction. However, its application in circumferential fingertip defects has rarely been reported. In this report, we describe two cases of circumferential fingertip defect reconstruction using a free SPBRA flap after wide local excision of subungual melanoma. The patients were women aged 74 and 63 years at the time of surgery. They presented with subungual melanoma on the right fourth finger and left thumb, in which both biopsies confirmed malignant melanoma in situ (Tis N0 M0), Breslow thickness of 0 mm (noninvasive). After wide local excision, circumferential defects, sized 2.5 × 6 and 2.7 × 7 cm, were formed on their fingertips. A vertically designed free SPBRA flap measuring 2.7 × 6 and 3 × 6 cm was elevated from the unaffected palm in each patient. After performing microvascular anastomosis, the flap was inserted transversely, wrapping the exposed phalangeal bone in a conical shape. The donor site was primarily closed. All flaps survived, and postoperative complications did not develop. Neither local recurrence nor distant metastasis was detected at the latest follow-up in either patient at 24 or 28 months postoperatively. The patients were satisfied with the natural contour of the reconstructed fingertip and recovered functions. In the evaluation of subjective sensory recovery using four scales (excellent, good, fair, and poor), they responded "fair" and "good," respectively. We suggest that the free SPBRA flap could be a reliable reconstructive method for circumferential fingertip defects.

Cascade of atopic dermatitis comorbidities in children after birth for 15 years.

BACKGROUND: Individuals with atopic dermatitis often develop other conditions. OBJECTIVE: This study aimed to determine how atopic dermatitis comorbidities develop in children over time. METHODS: This population-based administrative cohort study used national health insurance data. We traced individuals born in Korea between 2002 and 2003 to 2018. The date of initial atopic dermatitis diagnosis was set as the index date. Fifty-three childhood comorbidities of atopic dermatitis were identified as outcomes of interest by performing a comprehensive literature search and comparing the prevalence of diagnostic codes in children with and without atopic dermatitis. Four control children per individual in the atopic dermatitis group were randomly matched based on sex and index date. The association between atopic dermatitis and the development of each specified disease was assessed using proportional hazard assumption, followed by mapping of the temporal sequences of interconnected comorbidities. RESULTS: The atopic dermatitis and control groups contained 67,632 and 270,528 individuals, respectively. The median age at the index date was 10 months, whereas the median follow-up period was 15 years. Twenty diseases that were associated with a higher risk of atopic dermatitis were identified and a chain of interconnected conditions created. The progression began in childhood with febrile seizures, constipation, and asthma, and was later associated with the emergence of food allergy, allergic rhinitis, psychiatric disorders, and autoimmune diseases. CONCLUSION: Our study highlights the temporal nature of atopic dermatitis comorbidities in children, and indicates that an understanding of the comorbidities may inform its clinical management and treatment.

Evaluation of Long-Term Outcomes of Transverse Facial Cleft Repair.

OBJECTIVE: To evaluate the long-term outcomes of linear commissuroplasty and linear skin closure with a focus on commissural migration. DESIGN: Retrospective study. PATIENTS: Individuals who underwent transverse facial cleft repair at a single institution between 2004 and 2021. INTERVENTIONS: The disrupted orbicularis oris muscle was reoriented and sutured. A simple linear commissuroplasty technique was used, and the cheek skin was closed linearly without Z-plasty. MAIN OUTCOME MEASURES: The distances from Cupid's bow peak to the oral commissure were measured bilaterally, and the difference between the normal and cleft sides was obtained. Finally, its proportional value as a percentage of the total lip length was calculated from short- and long-term follow-up photographs. Cheek scarring and its effects on melolabial fold breakage were evaluated. RESULTS: Of the 18 patients who underwent transverse facial cleft repair, 12 were included in this study. The mean follow-up period based on medical photographs was 1773.5 days. The average proportional difference was 4.6%, demonstrating no observable commissural migration. There were no consistent trends in the direction of migration, either on the cleft or normal side. In patients with a transverse cleft crossing the melolabial fold, the folds appeared broken before and after the cleft repair surgery. CONCLUSIONS: No significant long-term commissural migration was observed after transverse facial cleft repair with simple linear commissuroplasty and linear skin closure. Deliberate positioning of the new oral commissure, proper myoplasty, and meticulous skin closure with minimal scar burden can be considered key procedures for successful transverse cleft repair.

Physiologically-based pharmacokinetic model for evaluating gender-specific exposures of N-nitrosodimethylamine (NDMA).

N-nitrosodimethylamine (NDMA) is classified as a human carcinogen and could be produced by both natural and industrial processes. Although its toxicity and histopathology have been well-studied in animal species, there is insufficient data on the blood and tissue exposures that can be correlated with the toxicity of NDMA. The purpose of this study was to evaluate gender-specific pharmacokinetics/toxicokinetics (PKs/TKs), tissue distribution, and excretion after the oral administration of three different doses of NDMA in rats using a physiologically-based pharmacokinetic (PBPK) model. The major target tissues for developing the PBPK model and evaluating dose metrics of NDMA included blood, gastrointestinal (GI) tract, liver, kidney, lung, heart, and brain. The predictive performance of the model was validated using sensitivity analysis, (average) fold error, and visual inspection of observations versus predictions. Then, a Monte Carlo simulation was performed to describe the magnitudes of inter-individual variability and uncertainty of the single model predictions. The developed PBPK model was applied for the exposure simulation of daily oral NDMA to estimate blood concentration ranges affecting health effects following acute-duration (≤ 14 days), intermediate-duration (15-364 days), and chronic-duration (≥ 365 days) intakes. The results of the study could be used as a scientific basis for interpreting the correlation between in vivo exposures and toxicological effects of NDMA.

A new knotless parametrial tissue ligation technique for safe total laparoscopic hysterectomy.

OBJECTIVE: Parametrial tissue ligation during total laparoscopic hysterectomy (TLH) is important in large uteri with large vessels. METHODS: A retrospective study was performed at Asan Medical Center for comparing TLH performed with a new knotless parametrial tissue ligation method and conventional laparoscopic-assisted vaginal hysterectomy (LAVH) from March 2019 to August 2021. For TLH, after anterior colpotomy, the parametrial tissue was ligated by anchoring the suture and making a loop in one direction three times using 1-0 V-LocTM 180 (Covidien, Mansfield, MA, USA) suture. Subsequently, the cranial part of the loop was cut using an endoscopic device. RESULTS: A total of 119 and 178 patients were included in the TLH and LAVH groups, respectively. The maximal diameter of the uterus was larger in the TLH group (106.29±27.16 cm) than in the LAVH group (99.00±18.92 cm, P=0.01). The change in hemoglobin (Hb) level was greater in the LAVH group than in the TLH group (P<0.001). The weight of the removed uterus was greater in the TLH group than in the LAVH group (431.95±394.97 vs. 354.94±209.52 g; P=0.03). However, when the uterine weight was >1,000 g, the operative times and change in Hb levels were similar between the two groups. In both groups, no ureteral complications occurred during or after surgery. CONCLUSION: Knotless parametrial tissue ligation using 1-0 V-LocTM 180 suture in TLH can be safely applied, even in cases with large uteri, without increased risks of ureteral injury or uterine bleeding.

Investigating the occurrence of autoimmune diseases among children and adolescents hospitalized for Mycoplasma pneumoniae infections.

Background: Mycoplasma pneumoniae infection is common in the general population and may be followed by immune dysfunction, but links with subsequent autoimmune disease remain inconclusive. Objective: To estimate the association of M. pneumoniae infection with the risk of subsequent autoimmune disease. Methods: This retrospective cohort study examined the medical records of South Korean children from 01/01/2002 to 31/12/2017. The exposed cohort was identified as patients hospitalized for M. pneumoniae infection. Each exposed patient was matched with unexposed controls based on birth year and sex at a 1:10 ratio using incidence density sampling calculations. The outcome was subsequent diagnosis of autoimmune disease, and hazard ratios (HRs) were estimated with control for confounders. Further estimation was performed using hospital-based databases which were converted to a common data model (CDM) to allow comparisons of the different databases. Results: The exposed cohort consisted of 49,937 children and the matched unexposed of 499,370 children. The median age at diagnosis of M. pneumoniae infection was 4 years (interquartile range, 2.5-6.5 years). During a mean follow-up time of 9.0 ± 3.8 years, the incidence rate of autoimmune diseases was 66.5 per 10,000 person-years (95% CI: 64.3-68.8) in the exposed cohort and 52.3 per 10,000 person-years (95% CI: 51.7-52.9) in the unexposed cohort, corresponding to an absolute rate of difference of 14.3 per 10,000 person-years (95% CI: 11.9-16.6). Children in the exposed cohort had an increased risk of autoimmune disease (HR: 1.26; 95% CI: 1.21-1.31), and this association was similar in the separate analysis of hospital databases (HR: 1.25; 95% CI 1.06-1.49). Conclusion: M. pneumoniae infection requiring hospitalization may be associated with an increase in subsequent diagnoses of autoimmune diseases.

Clinical Manifestations and Genotype of Primary Ciliary Dyskinesia Diagnosed in Korea: Multicenter Study.

PURPOSE: Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder that leads to secondary ciliary dysfunction. PCD is a rare disease, and data on it are limited in Korea. This study systematically evaluated the clinical symptoms, diagnostic characteristics, and treatment modalities of pediatric PCD in Korea. METHODS: This Korean nationwide, multicenter study, conducted between January 2000 and August 2022, reviewed the medical records of pediatric patients diagnosed with PCD. Prospective studies have been added to determine whether additional genetic testing is warranted in some patients. RESULTS: Overall, 41 patients were diagnosed with PCD in 15 medical institutions. The mean age at diagnosis was 11.8 ± 5.4 years (range: 0.5 months-18.9 years). Most patients (40/41) were born full term, 15 (36.6%) had neonatal respiratory symptoms, and 12 (29.3%) had a history of admission to the neonatal intensive care unit. The most common complaint (58.5%) was chronic nasal symptoms. Thirty-three patients were diagnosed with transmission electron microscopy (TEM) and 12 patients by genetic studies. TEM mostly identified outer dynein arm defects (alone or combined with inner dynein arm defects, n = 17). The genes with the highest mutation rates were DNAH5 (3 cases) and DNAAF1 (3 cases). Rare genotypes (RPGR, HYDIN, NME5) were found as well. Chest computed tomography revealed bronchiectasis in 33 out of 41 patients. Among them, 15 patients had a PrImary CiliAry DyskinesiA Rule score of over 5 points. CONCLUSIONS: To our knowledge, this is the first multicenter study to report the clinical characteristics, diagnostic methods, and genotypes of PCD in Korea. These results can be used as basic data for further PCD research.