Purpose: Claudins are a type of tight junction proteins in human endothelia and epithelia. Ozone brings about oxidative stress and lung inflammation in humans and experimental models. However, the impact of ozone on claudins in subjects with asthma remains poorly understood. The aim of this study was to find variations in the tight junction proteins claudin-4 and claudin-5 in subjects with asthma in relation to ambient ozone concentration. Methods: We previously recruited 50 patients with stable/exacerbated asthmatics and 25 controls. Furthermore, to examine the influence of ozone concentration, we reanalyzed 18 patients with stable or exacerbated asthma and 3 controls. The plasma claudin-4 and claudin-5 levels in response to high concentrations of ozone were compared to stable/exacerbated asthma, and controls. Results: The lung functions were significantly lower in subjects with asthma than those in controls. Blood eosinophil proportions were significantly higher in exacerbated asthmatics than in subjects with stable asthma. In high concentration period of ozone, plasma claudin-4 levels were significantly higher in subjects with exacerbated asthma (0.44 ± 0.30 ng/mL, P = 0.005) or stable asthma (0.38± 0.31 ng/mL, P= 0.009) compared to those in control subjects (0.16± 0.1 ng/mL). Plasma claudin-5 levels were lower in subjects with stable asthma (2.97 ± 1.38 ng/mL, P = 0.011) than in control subjects (6.92 ± 3.9 ng/mL), and higher in subjects with exacerbated asthma (7.49 ± 4.23 ng/mL, P < 0.001) than those with stable asthma. Conclusion These results reveal that claudins be changed in patients with asthma following ozone exposure in subjects with asthma.

Background: To precisely build a healthcare delivery system at regional levels, local patients’ healthcare service utilization patterns must be examined. Hence, this study utilized trend analysis of the relevance index of each disease of each essential medical service field at the municipal and provincial levels. Methods: This study analyzed customized databases released by the National Health Insurance Service from 2016–2020. Diseases defined in the Korean National Burden of Disease (KNBD) study were categorized into the following essential medical service fields:trauma care, cardiocerebrovascular, maternal and neonatal, mental health, infection, cancer, older adults’ care and rehabilitation, and others. Relevance index, the percentage of medical service utilization in a region by the residents of that region relative to their total medical service utilization, was examined by region (17 municipal and provincial regions) and disease area. The relevance index was determined based on the number of patients and the total outof-pocket expenses.Result: Eight of the 17 regions showed over a 90.0% relevance index in the infection area. In the cancer area, 14 regions (not including Seoul, Daegu, and Busan) had a relevance index lower than 75.0%. Throughout the analysis period (2016–2020), there were no significant variations in the relevance index. Diseases such as bone and connective tissue cancer (39.0%), neural tube defects (16.7%), and autism (57.1%) had low relevance index in the essential medical service fields. In all 17 regions, the relevance index of inpatients was lower than that of outpatients, and that for out-of-pocket expenses was lower than that based on the number of patients. Conclusion The relevance index of major diseases of each essential medical service field calculated in this study can provide good indicators for monitoring the level of an independent regional healthcare delivery system.

Qualitative research methodology has been applied with increasing frequency in various fields, including in healthcare research, where quantitative research methodology has traditionally dominated, with an empirically driven approach involving statistical analysis. Drawing upon artifacts and verbal data collected from in-depth interviews or participatory observations, qualitative research examines the comprehensive experiences of research participants who have experienced salient yet unappreciated phenomena. In this study, we review 6 representative qualitative research methodologies in terms of their characteristics and analysis methods: consensual qualitative research, phenomenological research, qualitative case study, grounded theory, photovoice, and content analysis. We mainly focus on specific aspects of data analysis and the description of results, while also providing a brief overview of each methodology’s philosophical background. Furthermore, since quantitative researchers have criticized qualitative research methodology for its perceived lack of validity, we examine various validation methods of qualitative research. This review article intends to assist researchers in employing an ideal qualitative research methodology and in reviewing and evaluating qualitative research with proper standards and criteria.

Purpose: Junctional adhesion molecule (JAM)-A is an immunoglobulin-like molecule that colocalizes with tight junctions (TJs) in the endothelium and epithelium. It is also found in blood leukocytes and platelets. The biological significance of JAM-A in asthma, as well as its clinical potential as a therapeutic target, are not well understood. The aim of this study was to elucidate the role of JAM-A in a mouse model of asthma, and to determine blood levels of JAM-A in asthmatic patients. Materials and Methods: Mice sensitized and challenged with ovalbumin (OVA) or saline were used to investigate the role of JAM-A in the pathogenesis of bronchial asthma. In addition, JAM-A levels were measured in the plasma of asthmatic patients and healthy controls. The relationships between JAM-A and clinical variables in patients with asthma were also examined. Results: Plasma JAM-A levels were higher in asthma patients (n=19) than in healthy controls (n=12). In asthma patients, the JAM-A levels correlated with forced expiratory volume in 1 second (FEV1%), FEV1/forced vital capacity (FVC), and the blood lymphocyte proportion. JAM-A, phospho-JNK, and phospho-ERK protein expressions in lung tissue were significantly higher in OVA/OVA mice than in control mice. In human bronchial epithelial cells treated with house dust mite extracts for 4 h, 8 h, and 24 h, the JAMA, phospho-JNK, and phospho-ERK expressions were increased, as shown by Western blotting, while the transepithelial electrical resistance was reduced. Conclusion These results suggest that JAM-A is involved in the pathogenesis of asthma, and may be a marker for asthma.

BACKGROUND: Immune cells express the vitamin (vit) D receptor, and vit D is a potent immune-modulator. A negative correlation between serum vit D levels and rheumatoid arthritis (RA) disease activity has been reported. Therefore, we aimed to investigate if the sufficient serum vit D level is helpful to control disease activity in RA patients treated with interleukin (IL)-6 receptor antibody tocilizumab.METHODS: RA patients taking tocilizumab were enrolled, and data were collected retrospectively. Disease activity scores (DAS) 28, serum vit D levels, modified Sharp scores of hand X-ray at the time of tocilizumab initiation, and follow-up data were analysed. Peripheral blood mononuclear cells were differentiated into T-helper (Th) 17 or osteoclasts in the presence of various concentrations of tocilizumab and/or 1,25(OH)₂D. Th17 proportions were analysed by fluorescence-activated cell sorting. Supernatant cytokine levels were determined by enzyme-linked immunosorbent assay.RESULTS: Among 98 RA patients taking tocilizumab, 34 (34.7%) had sufficient serum 25(OH)D levels (≥ 30 ng/mL) when tocilizumab was initiated. At 24 weeks, vit D sufficient patients had greater DAS28 reduction (64.6% ± 15.5% vs. 52.7% ± 20.7%, P = 0.004), and lower disease activity (91.2% vs. 70.3%, P = 0.018) or remission (82.4% vs. 57.8%, P = 0.014). These differences in DAS28 reduction and the proportion of patients with remission persisted at 48 weeks. However, there was no significant difference in hand and wrist erosion progression. In vitro, tocilizumab and 1,25(OH)₂D treatment synergistically suppressed IL-17 production and osteoclastogenesis.CONCLUSION: RA patients treated with IL-6 antibody show a better response when they have sufficient serum vit D. Tocilizumab and 1,25(OH)₂D synergistically suppress IL-17 production and osteoclast differentiation in RA patients.
Arthritis, Rheumatoid ; Cholecalciferol ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Follow-Up Studies ; Hand ; Humans ; In Vitro Techniques ; Interleukin-17 ; Interleukin-6 ; Interleukins ; Osteoclasts ; Retrospective Studies ; Vitamin D ; Vitamins ; Wrist

Background/Aims: N-acetylcysteine (NAC) affects signaling pathways involved in apoptosis, angiogenesis, cell growth and arrest, redox-regulated gene expression, and the inflammatory response. However, it is not known how the signal mechanism for tight junctional protein claudin (CLDN) 18 is regulated in asthma patients. Methods: To investigate the effects of NAC on CLDN18 expression in a mouse model of asthma, and to assess plasma levels of CLDN18 in asthma patients. A murine model of asthma induced by ovalbumin (OVA) was established using wild-type BALB/c female mice, and the levels of CLDNs, phosphorylated-pyruvate dehydrogenase kinase 1 (p-PDK1), and protein kinase B (Akt) pathway proteins following NAC treatment were examined by Western blotting and immunohistochemistry. In addition, the plasma levels of CLDN18 were evaluated in asthmatic patients and control subjects. Results: NAC diminished OVA-induced airway hyper-responsiveness and inflammation.Levels of CLDN18 protein were higher in lung tissue from OVA mice than tissue from control mice, and were increased by treatment with NAC or dexamethasone. Treatment with NAC or dexamethasone decreased the OVA-induced increase in interleukin-1α protein levels. Although treatment with NAC increased OVA-induced p-PDK1 protein levels, it decreased phosphorylated Akt (pAkt)/Akt levels. Soluble CLDN18 levels were lower in patients with asthma than in controls and were correlated with the percentage of neutrophils, forced expiratory volume in 1 second (FEV1)/forced vital capacity % (FVC%) and FEV1%. Conclusions CLDN18 plays a role in the pathogenesis of asthma and NAC diminishes airway inflammation and responsiveness by modulating CLDN18 expression.

Malaria is a potent burden on public healthcare worldwide due to requiring rapid diagnosis and treatment. Nowadays, prompt diagnosis with rapid diagnostic tests (RDTs) has been widely accepted as an effective diagnostic technique in malaria-endemic countries, primarily due to their easy operation, fast output, and straightforward interpretation. The global availability and use of RDTs have gradually grown over recent decades as field-applicable diagnostic tests for the reliable confirmation of malaria infection and proper case management. This study was conducted to evaluate diagnostic performance of 3 commercially available malaria RDT kits : BIOCREDITTM Malaria Ag Pf(pLDH), Malaria Ag Pf(pLDH/pHRPII), and Malaria Ag Pf/Pv(pLDH/pLDH) (where pLDH and pHRPII stand for plasmodium lactate dehydrogenase and histidine-rich protein 2, respectively) for the specific detection of Plasmodium falciparum. A total of 1,129 blood samples including 95 blood samples, confirmed as vivax malaria infection by microscopic examinations and a nested-PCR method, were tested for falciparum malaria infection. The overall sensitivity and specificity of Malaria Ag Pf(pLDH/pHRPII), Malaria Ag Pf/Pv(pLDH/pLDH), and Pf(pLDH) for P. falciparum were 99.0% and 100%, 95.8% and 100%, and 100% and 100%, respectively. It is proposed that the 3 RDT kits perform reliable level of diagnostic accuracy of detection for P. falciparum parasites.

Owing to global climate change, the global resurgence of vector-borne infectious diseases and their potential to inflict widespread casualties among human populations has emerged as a pivotal burden on public health systems. Tsutsugamushi disease (scrub typhus) in the Republic of Korea is steadily increasing and was designated as a legal communicable disease in 1994. The disease is a mite-borne acute febrile disease most commonly contracted from October to December. In this study, we tried to determine the prevalence of tsutsugamushi disease transmitted by chigger mites living on rodents and investigated their target vector diversity, abundance, and distribution to enable the mapping of hotspots for this disease in 2015. A total of 5 species belonging to 4 genera (109 mites): Leptotrombidium scutellare 60.6%, L. pallidum 28.4% Neotrombicula tamiyai 9.2%, Euschoengastia koreaensis/0.9%), and Neoschoengastia asakawa 0.9% were collected using chigger mite collecting traps mimicking human skin odor and sticky chigger traps from April to November 2015. Chigger mites causing tsutsugamushi disease in wild rodents were also collected in Hwaseong for the zoonotic surveillance of the vector. A total of 77 rodents belonging to 3 genera: Apodemus agrarius (93.5%), Crocidura lasiura (5.2%), and Micromys minutus (1.3%) were collected in April, October, and November 2015. The most common mite was L. pallidum (46.9%), followed by L. scutellare (18.6%), and L. orientale (18.0%). However, any of the chigger mite pools collected from rodent hosts was tested positive for Orientia tsutsugamushi, the pathogen of tsutsugamushi disease, in this survey.

The flaviviruses are small single-stranded RNA viruses that are typically transmitted by mosquitoes or tick vectors and are etiological agents of acute zoonotic infections. The viruses are found around the world and account for significant cases of human diseases. We investigated population of culicine mosquitoes in central region of Korean Peninsula, Incheon Metropolitan City and Hwaseong-si. Aedes vexans nipponii was the most frequently collected mosquitoes (56.5%), followed by Ochlerotatus dorsalis (23.6%), Anopheles spp. (10.9%), and Culex pipiens complex (5.9%). In rural regions of Hwaseong, Aedes vexans nipponii was the highest population (62.9%), followed by Ochlerotatus dorsalis (23.9%) and Anopheles spp. (12.0%). In another rural region of Incheon (habitat of migratory birds), Culex pipiens complex was the highest population (31.4%), followed by Ochlerotatus dorsalis (30.5%), and Aedes vexans vexans (27.5%). Culex pipiens complex was the predominant species in the urban region (84.7%). Culicine mosquitoes were identified at the species level, pooled up to 30 mosquitoes each, and tested for flaviviral RNA using the SYBR Green-based RT-PCR and confirmed by cDNA sequencing. Three of the assayed 2,683 pools (989 pools without Anopheles spp.) were positive for Culex flaviviruses, an insect-specific virus, from Culex pipiens pallens collected at the habitats for migratory birds in Incheon. The maximum likelihood estimation (the estimated number) for Culex pipiens pallens positive for Culex flavivirus was 25. Although viruses responsible for mosquito-borne diseases were not identified, we encourage intensified monitoring and long-term surveillance of both vector and viruses in the interest of global public health.