OBJECTIVES: As early as the Apollo 11 mission, astronauts experienced ocular, skin, and upper airway irritation after lunar dust (LD) was brought into the return cabin, drawing attention to its potential biological toxicity. However, the biological effects of LD exposure through the digestive system remain poorly understood. This study aimed to evaluate the impact of digestive exposure to lunar dust simulant (LDS) on gut microbiota and on the intestine, liver, kidney, lung, and bone in mice. METHODS: Eight-week-old female C57BL/6J mice were used. LDS was used as a substitute for lunar dust, and Shaanxi loess was used as Earth dust (ED). Mice were randomly divided into a phosphate buffered saline (PBS) group, an ED group (500 mg/kg), and a LDS group (500 mg/kg), with assessments at days 7, 14, and 28. Mice were gavaged once every 3 days, with body weight recorded before each gavage. At sacrifice, fecal samples were analyzed by 16S ribosomal RNA (rRNA) sequencing; inflammatory cytokine expression [interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α)] in intestinal, liver, and lung tissues was measured by real-time reverse transcription PCR (real-time RT-PCR); hematoxylin and eosin (HE) staining was performed on lung, liver, and intestinal tissues; Periodic acid-Schiff (PAS) staining was used to assess the integrity of the intestinal mucus barrier, and immunohistochemical staining was performed to evaluate the expression of mucin-2 (MUC2). Serum biochemical tests assessed hepatic and renal function. Femoral bone mass was analyzed by micro-computed tomography (micro-CT); osteoblasts and osteoclasts were assessed by osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) staining. Bone marrow immune cell subsets were analyzed by flow cytometry. RESULTS: At day 10, weight gain was slowed in ED and LDS groups. At days 22 and 28, body weight in both ED and LDS groups was significantly lower than controls (both P<0.05). LDS exposure increased microbial species richness and diversity at day 7. Compared with the PBS and ED groups, mice in the LDS group showed increased relative abundance of Deferribacterota, Desulfobacterota, and Campylobacterota, and decreased Firmicutes, with increased Helicobacter typhlonius and reduced Lactobacillus johnsonii and Lactobacillusmurinus. HE and PAS staining of the colon showed that mucosal structural disruption and goblet cell loss were more severe in the LDS group. In addition, immunohistochemistry revealed a significant downregulation of MUC2 expression in this group (P<0.05). No obvious pathological alterations were observed in liver HE staining among the 3 groups, and none of the groups exhibited notable hepatic or renal dysfunction. HE staining of the lungs in the ED and LDS groups showed increased perivascular inflammatory cell infiltration (both P<0.05). CONCLUSIONS LDS exposure via the digestive route induces gut dysbiosis, intestinal barrier disruption, pulmonary inflammation, bone loss, and bone marrow immune imbalance. These findings indicate that LD exposure poses potential health risks during future lunar missions. Targeted restoration of beneficial gut microbiota may represent a promising strategy to mitigate LD-related health hazards.
Animals ; Dust ; Mice ; Mice, Inbred C57BL ; Dysbiosis/etiology* ; Female ; Gastrointestinal Microbiome/drug effects* ; Moon ; Liver/metabolism* ; Digestive System/microbiology* ; Lung/metabolism* ; Kidney

OBJECTIVES: Due to prolonged exposure to cosmic radiation and meteorite impacts, lunar surface dust forms nanoscale angular particles with strong electrostatic adsorption properties. These dust particles pose potential inhalation risks, yet their pulmonary toxicological mechanisms remain unclear. Given the need for dust exposure protection in future lunar base construction and resource development, this study established an acute exposure model using lunar soil simulant (LSS) and used Earth soil (ES; Loess from Shaanxi, China) as a comparison to investigate lung injury mechanisms. METHODS: C57BL/6 mice were randomly assigned to 3 groups: Phosphate buffered saline (PBS), LSS, and ES, with 5 to 7 mice per group. Mice in the LSS and ES groups received a single intratracheal instillation to induce acute inhalation exposure. Body weight was monitored for 28 days. Mice were euthanized at days 3, 7, 14, and 28 post-exposure, and peripheral blood, bronchoalveolar lavage fluid (BALF), and lung tissues were collected. Immune cell subsets in BALF were analyzed using flow cytometry. Hematoxylin-eosin (HE) staining assessed lung structure and inflammation; periodic acid-Schiff (PAS) staining evaluated airway mucus secretion; Masson staining examined collagen deposition. Real-time reverse transcription PCR (real-time RT-PCR) was used to measure the mRNA expression of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and epithelial barrier genes (Occludin, Cadherin-1, and Zo-1). Lung tissues at day 7 were subjected to transcriptomic sequencing, followed by immune infiltration and pathway enrichment analyses to determine immunoregulatory mechanisms. RESULTS: Body weight in the ES group progressively declined after day 18 (all P<0.05), while the LSS group showed no significant changes compared with the control group. HE staining showed both LSS and ES induced inflammatory cell infiltration around airways and vasculature, which persisted for 28 days but gradually lessened over time. PAS staining revealed marked mucus hypersecretion in the LSS group at day 3, followed by gradual recovery; no significant mucus changes were observed in the ES group. Masson staining indicated no obvious pulmonary fibrosis in either group within 28 days. Real-time RT-PCR demonstrated significant upregulation of IL-1β and TNF-α in both LSS and ES groups, peaking on day 7, accompanied by downregulation of epithelial barrier genes (Occludin, Cadherin-1, and Zo-1)(all P<0.05). Transcriptomic analysis showed that both LSS and ES activated chemokine-related pathways and enriched leukocyte migration and neutrophil recruitment pathways. Further validation revealed upregulation of CXCL2 and MMP12 in the LSS group, whereas CXCL3 and MMP12 were predominantly elevated in the ES group. CONCLUSIONS Both LSS and ES can induce sustained lung injury and neutrophil infiltration in mice, though the underlying molecular mechanisms differ. Compared with ES, exposure to LSS additionally triggers a transient eosinophilic response, suggesting that lunar dust particles possess stronger immunostimulatory potential and higher biological toxicity.
Animals ; Mice ; Mice, Inbred C57BL ; Soil ; Lung Injury/etiology* ; Dust ; Bronchoalveolar Lavage Fluid ; Moon ; Lung/pathology* ; Inhalation Exposure/adverse effects* ; Male

As human deep space exploration enters a practical phase, ensuring astronaut health and safety has become a critical determinant of mission success. The cerebrovascular system, essential for maintaining brain function, is highly sensitive to environmental changes. Cerebrovascular diseases represent one of the characteristic adverse effects of deep space conditions such as microgravity and high-energy radiation, and have emerged as a frontier challenge in space medicine. Based on experiences from manned space missions, major research challenges persist, particularly the lack of experimental data specific to the lunar environment and the unclear threshold for low-dose radiation-induced injury. Elucidating the mechanisms and multifactorial interactions by which deep space environments impact cerebrovascular structure and function, and summarizing the key risk factors, pathological processes, and recent advances in monitoring and early-warning technologies for cerebrovascular diseases in lunar astronauts, and of crucial importance. A comprehensive understanding of the interplay between deep space environmental stressors and cerebrovascular injury, as well as the development of personalized prevention and intervention strategies, will provide both theoretical and practical foundations for safeguarding cerebrovascular health in future Chinese deep space missions, while promoting progress in related biomedical research, technological innovation, and international collaboration.
Humans ; Astronauts ; Cerebrovascular Disorders/etiology* ; Space Flight ; Weightlessness/adverse effects* ; Risk Factors ; Moon

Due to technological advances and the establishment of evidence-based medicine, radiological examinations are playing a crucial role in modern medicine, as a result of which they have been steadily increasing, and the rate of increase has intensified in the 2000s. Although this is a global phenomenon, the increase of radiological examinations in Korea is also high due to the introduction of the National Health Insurance Coverage Expansion Policy, so-called Moon Jae-in Care, for ultrasonography and magnetic resonance imaging. For accurate and rapid diagnosis of diseases, it is necessary for doctors to order appropriate radiological studies. However, the increase in radiological examination has created many problems, such as increased medical costs, decreased diagnostic accuracy due to radiologist burnout, and increased patient exposure to radiation. To reduce unnecessary imaging studies, a number of measures could be deployed including the development of clinical guidelines to select appropriate radiological examinations for each clinical situation.
Diagnosis ; Evidence-Based Medicine ; History, Modern 1601- ; Humans ; Insurance, Health ; Korea ; Magnetic Resonance Imaging ; Moon ; National Health Programs ; Ultrasonography

Percutaneous pulmonary valve implantation (PPVI) is recognized as a feasible and low risk alternative to surgery to treat dysfunctional right ventricular outflow tract (RVOT) in usually pluri-operated patients. Evolving technology allowed to develop different kind of prosthesis and to go from an initial treatment exclusively of stenotic conduit to an actual approach extended also to wide native RVOT. The Melody transcatheter pulmonary valve (TPV) and the Edwards Sapien valve are nowadays the most commonly implanted prostheses. However, other devices have been developed to treat large RVOT (i.e., the Venus p-valve, the Medtronic Harmony TPV, the Alterra Adaptive Prestent, and the Pulsta valve). Indications for PPVI are the same as for surgical interventions on pulmonary valve, with limits related to the maximum diameter of the available percutaneous prosthesis. Therefore, an accurate preoperative evaluation is of paramount importance to select patients who could benefit from this procedure. The overall periprocedural mortality incidence is around 1.4%, while freedom from RVOT reintervention ranges from 100% at 4 months to 70% at 70 months, according to the different published studies.
Freedom ; Heart Defects, Congenital ; Humans ; Incidence ; Mortality ; Prostheses and Implants ; Pulmonary Valve ; Venus

Blood Pressure ; Body Mass Index ; Cervix Uteri ; Elasticity ; Elasticity Imaging Techniques ; Female ; Hardness ; Heart Rate ; Humans ; Jupiter ; Labor Presentation ; Pregnancy ; Pregnant Women ; Premature Birth ; Reproducibility of Results ; Uterine Artery

PURPOSE: The newest technologies for digital implant impression (DII) taking are developing rapidly and showing acceptable clinical results. However, scientific literature is lacking data from clinical studies about the accuracy of DII. The aim of this study was to compare digital and conventional dental implant impressions (CII) in a clinical environment. MATERIALS AND METHODS: Twenty-four fixed zirconia restorations supported by 2 implants were fabricated using conventional open-tray impression technique with splinted transfers (CII group) and scan with Trios 3 IOS (3Shape) (DII group). After multiple verification procedures, master models were scanned using laboratory scanner D800 (3Shape). 3D models from conventional and digital workflow were imported to reverse engineering software and superimposed with high resolution 3D CAD models of scan bodies. Distance between center points, angulation, rotation, vertical shift, and surface mismatch of the scan bodies were measured and compared between conventional and digital impressions. RESULTS: Statistically significant differences were found for: a) inter-implant distance, b) rotation, c) vertical shift, and d) surface mismatch differences, comparing DII and CII groups for mesial and dist al implant scan bodies (P≤.05). CONCLUSION: Recorded linear differences between digital and conventional impressions were of limited clinical significance with two implant-supported restorations.
Clinical Study ; Dental Implants ; Denture, Partial, Fixed ; Jupiter ; Splints

PURPOSE: Children with sensitization to aeroallergens have decreased lung function and nasal patency. Our purpose was to determine the association of sensitization to different aeroallergens with airway function and nasal patency. METHODS: Four hundred and eighty-six randomly selected 11 year-old children who lived in Seongnam City were examined. Serum specific immunoglobulin E (IgE) levels against 6 common allergens (Dermatophagoidesfarinae, birch, cat, dog, Japanese hop and Alternaria), impulse oscillometry (IOS) results for the evaluation of airway dysfunction, and acoustic rhinometry for the determination of nasal airway patency were obtained. RESULTS: IOS indicated that children sensitized to Alternaria (n = 38, 7.8%) and dog dander (n = 69, 14.2%) had decreased lung function, based on resistance at 10 Hz (Rrs10; aβ = 0.0072; 95% CI, 0.017, 0.127; P = 0.010) and 1 Hz (Rrs1; aβ = 0.038; 95% CI, 0.001, 0.074; P = 0.042). Children sensitized to D. farinae (n = 281, 57.8%) had decreased post-decongestant nasal volume at 0 to 5 cm (aβ = −0.605; 95% CI, −1.005, −0.205; P = 0.003), but normal IOS results at all measured frequencies (P > 0.05). Increased serum eosinophil level was associated with Rrs1 (P = 0.007) and Rrs2 (P = 0.018) and post-decongestant nasal volume at 0 to 5 cm (aβ = −0.885; 95% CI, −1.331, −0.439; P < 0.001). CONCLUSIONS: Sensitivity to specific aeroallergens, serum eosinophil count and total IgE level had different associations with upper and lower airway dysfunction in urban children.
Allergens ; Alternaria ; Animals ; Asian Continental Ancestry Group ; Betula ; Cats ; Child ; Dander ; Dogs ; Eosinophils ; Gyeonggi-do ; Humans ; Immunoglobulin E ; Immunoglobulins ; Jupiter ; Lung ; Oscillometry ; Respiratory Function Tests ; Rhinometry, Acoustic

OBJECTIVES: We explored whether wideband tympanometry (WBT) could be used as a screening test for superior semicircular canal dehiscence (SSCD), and obtained new WBT data (given that the test is not yet in common clinical use) on patients with SSCD. METHODS: We compared the WBT data of patients clinically and radiologically diagnosed with SSCD in our hospital between 2013 and 2018 to those of healthy volunteers. We compared the resonance frequency (RF), maximum absorbance frequency (MAF), and maximum absorbance ratio (MAR). The t-test was used for statistical analysis with the significance level set to P<0.05. In addition, we used receiver operating characteristic analysis to derive cutoff values for SSCD diagnosis in terms of sensitivity and specificity. RESULTS: Seventeen patients (four with bilateral and 13 with unilateral disease; 17 ears) diagnosed with SSCD and 27 healthy volunteers (47 ears) were included. The mean RFs of the SSCD patients and healthy subjects were 548.7 Hz (range, 243 to 853 Hz) and 935.1 Hz (range, 239 to 1,875 Hz), respectively (P<0.001). The mean MARs of the SSCD patients and healthy subjects were 89.4% (range, 62% to 100%) and 82.4% (range, 63% to 99%), respectively (P=0.005). The mean MAFs of the SSCD patients and healthy subjects were 1,706.3 Hz (range, 613 to 3,816 Hz) and 2,668 Hz (range, 876 to 4,387 Hz), respectively (P<0.001). In terms of SSCD diagnosis, a MAR above 86% afforded 81% sensitivity and 77% specificity; an RF below 728 Hz, 86% sensitivity and 81% specificity; and an MAF below 1,835 Hz, 79% sensitivity and 67% specificity. CONCLUSION: WBT may be a useful clinical screening test for SSCD. The RF and MAF were lower, and the MAR higher, in SSCD patients than in normal controls.
Acoustic Impedance Tests ; Diagnosis ; Healthy Volunteers ; Humans ; Mars ; Mass Screening ; ROC Curve ; Semicircular Canals ; Sensitivity and Specificity

After the announcement of Moon Jae-in Government's plan (Moon's Care) for Benefit Expansion in National Health Insurance in August 2017, it is necessary to monitor the effects of the policy, especially household out-of-pocket payments (OOP). This paper aims to observe the current status and trend of OOP in Korea. Current health expenditure (CHE) was 144.4 trillion won in 2018, which accounts for 8.1% of gross domestic product (GDP) increased 9.7% from the previous year. Although GDP's share of CHE has been close to the average of the Organization for Economic Cooperation and Development (OECD) countries, the public fund's share was 59.8% of the total in 2018, which was lower than the OECD average of 73.5%. OOP's share was 32.9% in 2018, which decreased from 37.4% in 2008. The share of OOP of non-covered services was 20.0% in 2018, which decreased from 22.9% in 2008. The share of cost-sharing with third-party payers was 12.9% in 2018, which decreased from 14.5% in 2008. The OOP of non-covered services was significantly decreased in hospital and inpatient curative care, but the OOP of non-covered services was significantly increased in the medical clinic. The effect of Moon's Care was not showed in OOP through the results of 2017 and 2018, but further monitoring is needed because the Moon's Care is progressing and the observational period is short.
Family Characteristics ; Gross Domestic Product ; Health Expenditures ; Humans ; Inpatients ; Insurance, Health, Reimbursement ; Korea ; Moon ; National Health Programs ; Organisation for Economic Co-Operation and Development