Background: Although isotretinoin has been confirmed by clinical and experimental studies to be a teratogenic agent that causes fetal developmental abnormalities, its effects on placental development and placental-like extra-embryonic vascularization have not been sufficiently studied. The vascularization of the chorioallantoic membrane is structurally and functionally similar to mammalian placental vascularization, which provided the rationale for conducting this study. Aim: To study the effect of isotretinoin on chorioallantoic membrane vascularization using an in ovo chick embryo model. Materials and Methods: A comparative experimental control study was conducted using fertilized eggs of the same developmental age from Gallus gallus domesticus. At the HH10 embryonic stage, the control group received avian saline, while the experimental group was administered isotretinoin (5 µg/100 µL). Vascularization of the yolk sac and chorioallantoic membrane was evaluated at the macro- and tissue levels at 72 and 120 hours of embryonic development. Vessel branching order, vascular density, and capillary number were compared, and statistical analysis was performed using the Mann-Whitney U test. Result: In the control group, vascularization progressed actively, with abundant formation of third and fourth order vessels, resulting in a dense reticular network. In contrast, the isotretinoin treated group showed delayed vessel branching, a marked reduction in the number of third- and fourth-order vessels, and an overall decrease in vascular density of 40–60%. Histological analysis revealed thinning of the chorioallantoic membrane, loss of tissue layers, and thinning of vascular walls, and the number of capillaries was significantly lower than in the control group (p<0.01). In addition, the development of chorioallantoic membrane vascularization in chick embryos was found to be structurally and developmentally similar to mammalian placental vascularization. Conclusion Isotretinoin was shown to inhibit the development of the chorioallantoic membrane and markedly reduce vascularization and differentiation in an in ovo chick embryo model.

Background: Functional constipation is a common condition in early childhood, with an estimated global prevalence of approximately 3%. In Mongolia, functional constipation has been increasingly diagnosed among young children, particularly those aged 2–6 years. The condition is associated with abdominal pain, bloating, painful defecation, stool retention behaviors, and long-term physical and psychological complications. Although pediatric Tuina massage is widely used in Traditional Chinese Medicine as a non-pharmacological intervention, evidence regarding its effectiveness remains limited in the local context. Aim: To evaluate the effectiveness of therapeutic massage on stool frequency and stool consistency in children with functional constipation. Materials and Methods: A randomized controlled study was conducted between May and December 2025 at the “Bomborduk” Pediatric Traditional Medicine Center. Sixty children diagnosed with functional constipation (ICD-10 K59.04) were randomly assigned to a therapeutic massage group (n=30) or an exercise therapy group (n=30). Outcomes were assessed at baseline and after one month using the Constipation Assessment Scale (CAS) and the Bristol Stool Form Scale. Result: The mean age of participants was 3.75±0.94 years, with no significant difference between groups. In the massage therapy group, CAS scores decreased from 8.23±2.39 to 3.17±2.36, while Bristol Stool scores improved from 1.33±0.48 to 3.00±0.87. Improvements were significantly greater in the massage group compared with the exercise therapy group (p < 0.05). Conclusion Therapeutic massage is a safe and effective non-pharmacological intervention that significantly improves stool consistency and reduces constipation severity in children with functional constipation.

Background: Type I hypersensitivity, commonly known as an allergic reaction, is characterised by an IgE-mediated immune response triggered when foreign proteins enter the body. During allergic reactions, cytokines such as IL-4, IL-5, IL-9, and IL-13, secreted by T-helper 2 (Th2) cells, play a crucial role in activating immune effector cells like eosinophils and mast cells, which contribute significantly to airway inflammation and obstruction. Conversely, interferon-gamma (IFN-γ), produced by Th1 cells, suppresses Th2-mediated responses and plays an essential role in regulating allergic inflammation. Therefore, determining the balance of cytokines produced by Th1 and Th2 cells is crucial for understanding the mechanisms underlying allergic responses. Aim: We aimed to induce an allergic response in experimental animals using ovalbumin and to determine the levels of IL-4 and IFN-γ cytokines using an in-house enzyme-linked immunosorbent assay (ELISA). Materials and Methods: A total of 20 female C57BL/6 mice aged 6–8 weeks were selected for the experiment and randomly divided into two groups: control and experimental groups. The concentrations of IL-4 and IFN-γ cytokines in mouse serum were determined using an in-house enzyme-linked immunosorbent assay (ELISA). Result: Compared to the control group, the levels of IL-4 and IFN-γ cytokines in the serum of allergic model-induced C57BL/6 mice were determined to be 513.7 pg/mL and 193.2 pg/mL, respectively. A statistically significant difference was observed in IL-4 cytokine levels between the two groups (p < 0.001). Conclusion In the allergic model group, serum levels of IL-4 cytokine were elevated, while IFN-γ cytokine levels were decreased, suggesting a predominant Th2-type immune response.

Background: Atopic dermatitis is a chronic, relapsing inflammatory skin disorder in which immune dysregulation and skin barrier dysfunction play crucial roles, alongside neuroendocrine factors. Psychological stress influences the activity of the hypothalamic-pituitary-adrenal (HPA) axis, thereby altering cortisol secretion and inflammatory responses. However, the relationships among cortisol levels, neutrophil-to-lymphocyte ratio (NLR), psychological parameters, and disease severity remain insufficiently explored. Aim: To compare cortisol levels, neutrophil-to-lymphocyte ratio, and psychological parameters between adults with atopic dermatitis and healthy controls. Materials and Methods: A case-control study was conducted including 12 patients with atopic dermatitis and 12 healthy controls. Serum cortisol levels and complete blood counts (for NLR calculation) were assessed. Psychological status was evaluated using the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7). Disease severity was measured using the SCORAD index. Statistical analyses included group comparisons and correlation analyses. Results: Cortisol levels in the atopic dermatitis group were significantly lower than those in the control group (p<0.001). Cortisol levels showed a significant negative correlation with SCORAD scores (r = -0.65, p = 0.021) and GAD-7 scores (r=-0.56, p=0.036). A negative correlation was also observed between disease duration and cortisol levels (r=-0.53, p=0.075), although this did not reach statistical significance. Conclusion Dysregulation of the HPA axis in atopic dermatitis, reflected by reduced cortisol levels, may be associated with increased disease severity and psychological stress. These findings highlight the importance of incorporating psychological assessment into the comprehensive management of atopic dermatitis.

Background: Hidradenitis suppurativa (HS) is a chronic, recurrent inflammatory disorder of the hair follicle that predominantly affects areas rich in apocrine sweat glands, such as the axillae and groin. Clinically, it is characterized by painful nodules, abscess formation, sinus tract development, and scarring. Diagnosis is primarily based on clinical findings; however, due to limited awareness of the disease, it is often diagnosed at a late stage. Misdiagnosis and inappropriate management are common, leading to chronic disease progression. Consequently, HS significantly impairs quality of life through reduced work capacity, psychological distress, and social isolation. Disease severity is commonly assessed using the Hurley staging system and the Sartorius scoring system. We present a rare case of hidradenitis suppurativa encountered in dermatological practice. Case presentation A 35-year-old male patient (initials L.B.) presented with recurrent, painful lesions in both axillary regions associated with purulent discharge. The condition had persisted over a prolonged period with repeated exacerbations. The patient had attempted self-treatment at home without improvement and was subsequently admitted to the Department of Dermatology at the National Center for Dermatology with a diagnosis of DS: L73.2 (hidradenitis suppurativa). The patient was treated with systemic antibiotics (doxycycline and cefazolin), retinoids, supportive therapy, and topical treatment. In addition, intralesional triamcinolone injections were administered into active nodules, which proved effective in rapidly reducing inflammation, pain, and purulent discharge.

Background: Air pollution remains a major environmental health risk in Mongolia, particularly in Ulaanbaatar. Although a legal and policy framework for air quality management is in place, evidence on how legislation, institutional arrangements, monitoring systems, and health protection mechanisms function together remains limited. Objective: To assess air pollution levels, evidence of health impacts, and implementation of the legal and regulatory environment for air quality management in Mongolia, and to identify key gaps in comprehensive air quality management from the perspective of protecting children and other vulnerable populations. Materials and Methods: A mixed-methods assessment was conducted in 2023 combining document review, analysis of secondary air quality monitoring data, and qualitative key informant interviews. Historical monitoring data for SO₂, NO₂, PM₁₀, PM₂.₅, CO, and O₃ in Ulaanbaatar for 2008–2017 were analyzed. Relevant laws, policies, standards, and institutional arrangements were reviewed, while qualitative interview data were analyzed thematically. The findings were further contextualized using a targeted evidence update for 2021–2026 and a post hoc secondary analysis based on the five pillars of the 2026 comprehensive air pollution management framework. Results: Air pollution showed a marked seasonal pattern. Mean SO₂ concentrations were 7.57 times higher and NO₂ concentrations 1.66 times higher during the cold season than during the warm season. The 24-hour mean concentration of PM₂.₅ during the cold season was 114.10 µg/m³, while PM₁₀ was 226.77 µg/m³; cold-season PM₂.₅ was 3.9 times higher than in the warm season. Although Mongolia has an established constitutional and sectoral legal basis for air quality management, key informants identified persistent gaps in regulatory enforcement, intersectoral coordination, institutional capacity, human resources, technical capacity, economic incentives, and civil society participation. Monitoring coverage was uneven across pollutants, with limitations in spatial coverage of PM₂.₅ and integration of air quality and health data. The framework-based analysis further identified gaps across rights protection, source-specific regulation, institutional accountability, standards and monitoring, and implementation programmes. Conclusion The principal challenge for air quality governance in Mongolia is not the absence of legislation, but the gap between legal and policy provisions and their effective implementation and measurable health outcomes. Strengthening a child-centred, source-based and multisectoral air quality management system that integrates institutional accountability, monitoring, health surveillance, financing, and enforcement is warranted.

Introduction: Arsenic is a widespread environmental metalloid that poses a global health risk, particularly through contamination of drinking water. Exposure arises from natural and human activities through ingestion, inhalation, and skin absorption. Its absorption and toxicity vary by chemical form, with trivalent arsenic generally more toxic than pentavalent arsenic. Once absorbed, arsenic can accumulate in tissues and body fluids. Objective: To compare urinary arsenic concentrations among adults residing in selected mining and non-mining areas of Mongolia. Materials and Methods: This cross-sectional study included 422 adults from mining areas (n = 333; Bayan-Undur, Tsogtsetsii, and Khanbogd) and non-mining areas (n = 89; Bulgan and Bayandalai). Questionnaire data on sociodemographic characteristics, occupation, smoking, and dietary habits were collected. Urine samples were analyzed using inductively coupled plasma mass spectrometry. Arsenic concentrations were summarized as geometric means (GMs) with 95% confidence intervals (CIs). Results: Of the 422 participants, 242 (57.3%) were women. The GM urinary arsenic concentration was 31.10 µg/L [95% CI, 28.96–33.58] in mining areas and 26.42 µg/L [95% CI, 22.98–30.39] in non-mining areas. Among mining communities, GMs were 33.45 µg/L in Bayan-Undur, 25.49 µg/L in Tsogtsetsii, and 24.82 µg/L in Khanbogd. In the non-mining communities, GMs were 29.43 µg/L in Bulgan and 23.02 µg/L in Bayandalai. Conclusion The urinary arsenic concentration was higher among adults in the selected mining areas, with variation between communities. Further analyses accounting for potential confounders, together with arsenic speciation and environmental measurements, are needed to clarify exposure sources and the contribution of mining activities.

Introduction: The World Health Organization (WHO) reports that noise pollution leads to a variety of short-term and long-term health issues, including sleep disorders, cardiovascular diseases, impaired concentration, decreased performance at work and school, and hearing difficulties. It has been established that for every 10 dB increase in environmental noise, the incidence of heart attacks among individuals aged 65 and older increases by 3.9% compared to those living in quieter environments (Seidler, et al., 2016). Furthermore, it has been found that noise pollution exceeding 65 dB is directly related to hypertension among residents living along high-traffic roads. Objective: To assessing traffic load and noise pollution on the roads of Ulaanbaatar Materials and Methods: The study was a cross-sectional survey conducted to determine noise pollution at 15 locations along roads such as Sun Road, Peace Avenue, Ard-Ayush Street, and Ikh Toiruu. Measurements were taken during morning (7-9 AM), afternoon (12-2 PM), evening (5-7 PM), and night (11 PM-1 AM) using a Noise Meter, Sound Level Meter, and portable equipment. Measurements were conducted at one point 100-200 meters from the main road, with three repetitions to assess hearing levels. Statistical analysis was performed using SPSS-24 software, and the results were compared to the Air Quality Technical General Requirements MNS 4585:2016 standard (During the day (07:00-22:00), 60 dB(A), and at night (22:00 07:00), 45 dB(A)). Results: The measurement results revealed that the maximum noise value in the morning (7-9 AM) was 83 dB(A), the minimum noise value was 51 dB(A), and the average of the maximum noise values was 74.1±4.7 dB(A). The maximum noise value during the day was 97 dB(A), the minimum noise value was 47 dB(A), and the average of the maximum noise value was 74.4±6.9 dB(A). In the evening, the maximum noise value was 88 dB(A), the minimum noise value was 47 dB(A), and the average of the maximum noise value was 74.4±6.6 dB(A). For the night measurements, the maximum noise value was 86 dB(A), the minimum noise value was 49 dB(A), and the average of the maximum noise value was 69.4±7.7 dB(A).
When calculating the average noise pollution on weekdays and weekends, the average of the max and min values during the morning, evening, and night on weekdays was 0.59-4.33 dB(A) higher than that of the weekend. The average maximum value during the day on weekends was 2.79 dB(A) higher than that of weekdays. The number of vehicles participating in road traffic showed a strong positive correlation with environmental noise (Rxy=0.660, p=0.0001), and the number of times the horn was sounded also revealed strong positive correlation with environmental noise (Rxy=0.674, p=0.029). Conclusion The noise level along the main roads exceeds the permissible limits set by the "Air Quality. Technical General Requirements MNS 4585:2016" standard by 37 dB(A) during the day and by 41 dB(A) at night. The average maximum value during the day exceeds the standard by 14.6 dB(A). This indicates that Ulaanbaatar is experiencing noise pollution at levels that negatively affect the health of the urban population.

Background: Indoor air quality in schools is an important environmental health concern because children spend a substantial proportion of their time in classrooms and are particularly vulnerable to air pollutants. Objective: To assess common chemical, and biological pollutants in the indoor air of general education schools in Ulaanbaatar. Methods: A cross-sectional study was conducted from October 10, 2025, to March 1, 2026, in 16 purposively selected schools and 32 classrooms across six districts of Ulaanbaatar. PM2.5, PM10, CO₂, and microclimatic parameters were monitored continuously for seven days. Volatile organic compounds, formaldehyde, BTEX compounds, and radon were also measured. Airborne microorganisms were assessed using 160 air samples, and 160 surface swabs were collected. Results were compared with MNS 7106:2026, MNS 5484:2005, and MNS 6410:2018 standards. Results: The mean 24-hour concentrations of PM2.5 and PM10 were 25.2 and 36.1 µg/m³, respectively. PM2.5 exceeded the permissible level during winter and in schools located in apartment areas, whereas the mean PM10 concentration met the acceptable level. Total bacteria were detected in all air samples, with a mean concentration of 1,733.25 CFU/m³. Mould and fungi were detected in 56.3% of classrooms, and enteric bacteria were detected in 4.3% of surface swabs. Radon levels remained below the permissible limit, and pathogenic bacteria were not detected. Formaldehyde was detected in all samples, while total VOCs and toluene were detected in 81.3%; their mean concentrations remained within acceptable levels. In one classroom, the concentration of benzene was detected approximately 30 times higher the permissible level. Conclusion Although some indoor air-quality indicators met the relevant standards, PM2.5, total bacteria, mould and fungi, surface enteric bacteria, and benzene contamination require improvement and may pose health risks to children. Regular ventilation, improved cleaning and hygiene, proper maintenance of HEPA devices, and routine monitoring of particulate matter, mould, and VOCs are needed.

Introduction : Noncommunicable diseases (NCDs) caused at least 43 million deaths in 2021, equivalent to 75% of non-pandemic-related deaths globally. Cardiovascular diseases account for most NCD deaths, or at least 19 million deaths in 2021, followed by cancers (10 million), chronic respiratory diseases (4 million), and diabetes (over 2 million including kidney disease deaths caused by diabetes). These four groups of diseases account for 80% of all premature NCD deaths. According to the Fourth National Survey on the Prevalence of Noncommunicable Diseases, Injuries, and Their Risk Factors: 14.0% of adults aged 15–69 have experienced a heart attack or stroke, 11.0% report taking aspirin to prevent or manage cardiovascular disease (CVD), 2.2% use lipid-lowering medications (statins) for CVD prevention or treatment, among adults aged 40–69, 19.3% are at high risk of developing CVD within the next 10 years. These findings underscore the urgent need to strengthen cardiovascular disease prevention efforts and improve the management of key risk factors in Mongolia. Goal: To determine the population’s knowledge, attitudes, and practices related to cardiovascular disease risk factors and healthy lifestyle behaviors. Materials and Methods: This descriptive cross-sectional study included 2,532 participants aged 18–69 years from all 21 provinces of Mongolia and Ulaanbaatar city, as part of the “Cardiology, Cardiac Surgery, and Telemedicine in Mongolia” (MON/007) Project. Data were collected using a structured questionnaire comprising six sub-sections, designed to assess knowledge, attitudes, and practices related to 10 modifiable cardiovascular risk factors. Ethical approval was obtained prior to the study, and data were analyzed using SPSS version 23. Results: Thirty-three percent of study participants reported having no knowledge of cardiovascular disease, indicating that roughly one in three adults consider themselves to have little or no understanding of cardiovascular health. In the study, 53.0% of participants reported being unaware of the symptoms of a heart attack, while 42.0% did not recognize the symptoms of a stroke. Among participants who could identify these symptoms, 68.0% indicated dizziness as a sign of hypertension, 65.0% reported headache, and 58.0% noted blurred vision. Among the respondents, 31.0% knew that the normal arterial blood pressure for an adult is 120/80 mmHg, 57.0% were aware that an adult should sleep 7–8 hours per day, 13.0% knew about body mass index (BMI), 30.0% were aware of fasting blood glucose levels, and 44.0% recognized that adults should engage in 30 minutes of physical activity daily. Knowledge of key physiological indicators was significantly associated with educational attainment, gender, and age group, with lower levels of awareness observed among participants with lower education, males, and younger adults (p=0.001). The majority of participants (75.0%-96.0%) reported being aware of the modifiable risk factors for cardiovascular disease. Among the study participants, nine out of ten agreed that maintaining a healthy lifestyle includes regular physical activity, exercising, walking short distances, and understanding that hypertension is harmful and smoking adversely affects the heart. Furthermore, 80–85% reported avoiding excessive alcohol consumption, and 79% believed that cardiovascular disease is preventable. To prevent or reduce obesity, a risk factor for cardiovascular disease, 49.0% of participants reported engaging in regular physical activity, while 33.0% reported following a healthy diet. Among all study participants, 61.0% had never checked their cholesterol levels, 49.0% had never measured their blood glucose, and 15.0% had never monitored their blood pressure. Among respondents exhibiting 1–3 common risk factors, the majority were female, aged 25–34 years, living in rural areas or ger districts, with secondary or specialized secondary education, employed in government institutions, and had a normal BMI. In contrast, among those with 7 or more common risk factors, the majority were male, aged 35–44 years, residing in Ulaanbaatar, living in ger districts, and employed in private organizations. Conclusion Most of surveyed participants had sufficient knowledge and positive attitudes toward modifiable risk factors for cardiovascular diseases (p=0.001). However, they exhibited inadequate preventive practices related to these risk factors. This indicates the importance of targeted intervention on behavior change to address this gap.