Background: Ambient and household air pollution remain leading risk factors for global morbidity and mortality. Exposure to fine particulate matter (PM₂.₅) is associated with increased risks of cardiovascular and respiratory diseases, as well as lung cancer, metabolic and neurological disorders, and immune dysfunction. In urban areas of Mongolia, air pollution reaches critical levels during the winter season. Although improved solid fuels have been introduced in recent years, their impact on both outdoor and indoor air quality remains insufficiently characterized. Aim: To compare outdoor and household air pollution levels in Ulaanbaatar and Darkhan cities. Materials and Methods: Outdoor air pollution data for Ulaanbaatar were obtained from fixed monitoring stations of the National Agency for Meteorology and Environmental Monitoring for the period 2014–2026, with seasonal comparisons performed. For indoor air quality assessment, a longitudinal study was conducted among 240 households (apartments, houses, and traditional gers) in Ulaanbaatar and Darkhan from 2023 to 2026. PM₂.₅ concentrations were measured using real-time sensors (PurpleAir sensor), deployed for 14–21 days per season (winter and summer) in each household, recording data at 10-minute intervals over 24-hour periods. Result: Between 2014 and 2026, the 24-hour mean concentrations in Ulaanbaatar were 60.5 µg/m for PM₂.₅, 117.3 µg/m for PM₁₀, 37.3 µg/m for NO₂, 41.8 µg/m for SO₂, and 27.5 µg/m for O₃. While particulate matter levels showed a decreasing trend following the introduction of improved fuels, SO₂ concentrations increased, and overall pollution levels remained higher than those observed in Darkhan. Indoor PM₂.₅ concentrations were higher in Ulaanbaatar compared to Darkhan (60.7±86.1 vs 48.4±96.7 µg/m). Significant differences were observed by housing type (p<0.0001), with higher concentrations in households using solid fuels (houses and gers) and lower levels in apartments. These findings indicate substantial variability in indoor air pollution by city, housing type, and season, with persistently elevated exposure levels. Conclusion Outdoor air pollutant concentrations in Ulaanbaatar, including particulate matter, NO₂, and SO₂, exceed national standards and WHO guideline values by 1–4 times. Indoor PM₂.₅ pollution is higher in Ulaanbaatar than in Darkhan and varies significantly by housing type and season, indicating a high and heterogeneous exposure burden among urban populations.

Background: Allergic and atrophic forms of chronic rhinitis are common among the population, characterized by a chronic progressive course with a tendency toward increasing prevalence. Worldwide, allergic rhinitis affects approximately 10–40% of adults and 2–25% of children. According to a study conducted in Mongolia, the prevalence of allergic rhinitis among adults in Ulaanbaatar was reported to be 23.6%, with an increasing trend anticipated in the future. In allergic and atrophic rhinitis, structural alterations occur in the nasal mucosa, including disruption of the normal architecture of the pseudostratified epithelium and ciliated cells, accompanied by changes in goblet cell number and dysfunction of their activity, resulting in a complex pathological process. In otorhinolaryngology practice in Mongolia, there is a relative lack of studies investigating the ultrastructural changes of the nasal mucosa in allergic and atrophic rhinitis. Aim: To compare ultrastructural and histological changes of the nasal mucosa in allergic and atrophic rhinitis. Materials and Methods: Ethical approval was obtained from the Research Ethics Review Committee of the Mongolian National University of Medical Sciences at the meeting held on April 24, 2020 (Protocol No. 2020/З-04). Appropriate ethical permission was also obtained from the EMJJ ENT Hospital. Nasal mucosal tissue samples were collected from surgically resected specimens of patients aged 20–45 years diagnosed with allergic and atrophic rhinitis. The mucosal specimens were processed at the Institute of Biomedical Sciences of the Mongolian National University of Medical Sciences. Samples were fixed and dehydrated according to the protocol, coated with 100 Å gold, and examined using a scanning electron microscope (FEI Quanta FEG 250, USA). In addition, paraffin blocks were prepared, sectioned at 4 μm thickness, stained with Hematoxylin and Eosin, and analyzed histologically. Results: In allergic rhinitis, the pseudostratified epithelium was relatively preserved; however, disorganization of ciliated cells, partial loss of cilia, and goblet cell hyperplasia were observed. In contrast, atrophic rhinitis showed epithelial thinning, near-complete loss of ciliated structures, glandular atrophy, and submucosal fibrosis. Conclusion Allergic rhinitis is associated with relatively mild and predominantly functional mucosal alterations, whereas atrophic rhinitis demonstrates severe structural damage with irreversible impairment of mucosal protective function.

Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by epidermal barrier dysfunction, immune dysregulation, and significant clinical burden. In Mongolia, research on AD has increased over the past decade; however, findings remain fragmented across various areas. Aim: To synthesize evidence from studies conducted in Mongolia over the last 10 years regarding the pathogenesis, clinical features, diagnosis, and treatment of atopic dermatitis. Materials and Methods: A narrative review was conducted, including original studies on Mongolian populations published within the last decade. Studies addressing skin barrier function, immunological mechanisms, genetic factors, environmental exposures, clinical severity, diagnostic tools, and treatment approaches were included. Results: The study findings show that genetic studies identified polymorphisms in the filaggrin gene and, more recently, mutations in the GCDH gene, suggesting these are linked to AD severity and allergen sensitization. Research on the immunopathogenesis of AD revealed that Th2-type cytokines, especially IL-3 and IL-4, are associated with pruritus and disease severity. Additionally, decreased skin hydration and increased transepidermal water loss in individuals with AD were linked to greater disease severity. Disease severity was evaluated using the SCORAD, EASI, and POEM tools, with most studies reporting that mild-to-moderate AD was most common. Clinically, symptoms like pruritus and sleep disturbances were evident. Additionally, clinical severity was associated with laboratory markers, particularly total IgE levels. The high rate of sensitization to inhalant and food allergens suggests that extrinsic atopic dermatitis (AD) may be common in the Mongolian population. In treatment studies using locally relevant natural products in Mongolia, such as seabuckthorn oil and Shargaljuut mineral spring spray, these products were associated with clinical improvement, suggesting they could serve as additional therapeutic options. Conclusion Research on atopic dermatitis in Mongolia has progressed in several areas; however, the current evidence remains limited and is mostly based on cross-sectional, small-sample, single-center, hospital-based studies. Therefore, there is a need for future comprehensive studies that are multicenter, long-term, and involve larger populations.

Background: Currently, colorectal cancer (CRC) ranks as the third most common cancer and the second leading cause of cancer-related mortality worldwide. CRC frequently metastasizes to the liver (50%), lungs (10–15%), peritoneum (4%), bones (10.7%–23.7%), brain (0.3%–6%), and spinal cord. Approximately 35% of CRC cases are diagnosed before distant metastasis, 36% upon lymph node involvement, and 23% after distant organ metastasis. Although several studies have established primary tumor models in mice in our country, there are limited studies on experimental lung metastasis models, prompting the need for this research. Aim: To establish and evaluate a lung metastasis model of colorectal cancer in C57BL/6J mice using the MC38 cell line. Materials and Methods: This study was conducted at the Institute of Biomedical Sciences, Mongolian National University of Medical Sciences. Approval was obtained from the Ethics Review Board of the Mongolian National University of Medical Sciences (2023/3-09) and all laboratory safety regulations and protocols were strictly followed. Male C57BL/6J mice bred at the Experimental Animal Center of Mongolian National University of Medical Sciences were used. MC38 murine colorectal carcinoma cells were cultured and injected intravenously (via the tail vein) at a concentration of 0.25×10⁶ cells per mouse (n=12) to induce lung metastasis. Histological analysis was subsequently performed. Results: Histological examination revealed significant alterations in lung tissue architecture, characterized by areas of dense infiltration by pleomorphic, hyperchromatic cells, disrupting the normal alveolar structure. No histological abnormalities were observed in other organs. Conclusion Intravenous injection of MC38 colorectal adenocarcinoma cells into the tail vein of C57BL/6J mice successfully induced lung metastases, characterized by hyperchromatic, pleomorphic cell infiltrates forming glandular structures within the lung parenchyma.

Background: Hypokalemia is considered when the serum potassium level is less than 3.5 mmol/L. Clinical research indicates that hypokalemia affects 20% of hospitalized patients, and in 24% of these cases, inadequate interventions result in life-threatening complications. At present, there is no research available on the prevalence, management, and outcomes of hypokalemia in hospitalized patients, which justifies the need for this study. Aim: The study aimed to examine the prevalence of hypokalemia and the effectiveness of its management in hospitalized patients within the internal medicine department, in relation to the knowledge of doctors and resident physicians. Materials and Methods: This hospital-based retrospective study included a total of 553 cases of patients hospitalized in the Internal Medicine Department of the Mongolia Japan Hospital between January 2024 and August 2024. Patients with a potassium level of <3.5 mmol/L were diagnosed with hypokalemia, and the effectiveness of potassium replacement therapy was evaluated according to the method of supplementation employed. Results: The prevalence of hypokalemia among hospitalized patients in the Internal Medicine Department was 9.8% (54 cases). Based on the study criteria, 42 cases of hypokalemia were selected for further analysis, and a total of 118 potassium replacements were performed through oral, intravenous, and mixed methods. Following potassium replacement therapy, 37.3% (44) of patients achieved normalized potassium levels, while 62.7% (74) still had persistent hypokalemia. Conclusion According to the study results, the prevalence of hypokalemia among hospitalized patients in the Internal Medicine Department is 9.8%. The method of potassium replacement and the severity of hypokalemia do not impact the normalization of potassium levels, with the critical factor being the proper dosage of supplementation. The knowledge of doctors and resident physicians regarding hypokalemia is insufficient, and there is a need to implement guidelines and protocols for potassium replacement therapy in daily clinical practice.

Background: According to the World Health Organization (WHO), 6.7 million people die annually due to air pollution caused by solid fuel use, with the majority of deaths resulting from respiratory diseases and cardiovascular conditions. In Mongolia, air pollution ranks as the fourth leading risk factor contributing to mortality, following hypertension, diabetes, and other major health risks. Although there have been numerous studies on outdoor air pollution in Mongolia, research linking indoor air pollution at the household level with the health status of residents remains limited. Aim: To compare indoor PM2.5 concentrations in households of Ulaanbaatar and Darkhan and examine their association with hypertension during the winter season. Materials and Methods: The study was conducted during November and December 2023, and January 2024, involving 240 households in Ulaanbaatar and Darkhan. Indoor PM2.5 concentrations were measured using Purple Air real-time sensors continuously for 24 hours over approximately one month. After measuring indoor air pollution, individuals aged 18–60 years living in the selected households were recruited based on specific inclusion criteria. Blood pressure was measured three times and the average value was recorded. Information on respiratory illnesses was collected through structured questionnaires. Statistical analysis was performed using STATA version 19.0. Results: A total of 241 households participated in the study, with 116 from Ulaanbaatar and 125 from Darkhan. Of the participants, 46.5% were male and 53.5% were female. In terms of housing type, 96 households (39.8%) lived in gers, 97 (40.2%) lived in stove-heated houses, and 48 (19.9%) lived in apartments. Among all participants, 66.0% (n=159) had hypertension and 34.0% (n=79) had normal blood pressure. Among participants aged over 40, 69.9–88.5% had hypertension, which is statistically significantly higher compared to younger individuals (p=0.0001). By body mass index, 75.3% (n=72) of overweight individuals and 78.4% (n=58) of obese participants had hypertension, showing a statistically significant difference compared to participants with normal weight (p=0.0001). The 24-hour average concentration of indoor PM2.5 was measured using the Purple Air device, and the levels in gers and stove-heated houses exceeded the limit set by the MNS 4585:2025 standard (37.5 µg/m³) Conclusion This study identified a relationship between environmental factors, such as air pollution and housing type, and the prevalence of hypertension. The indoor PM2.5 concentration in gers and stove-heated houses was above the standard limit, indicating a negative impact on the health of those residents. Furthermore, the high prevalence of hypertension among participants over the age of 40 and those who are overweight suggests a possible link to lifestyle and environmental conditions.

Study about caeserean section In nulliparous women Introduction: Cesarean section rates in Mongolia exceed WHO recommendations of 5–15%, reaching 27.6% nationally and 34.1% at the First Maternity Hospital between 2019–2023. C-sections, while life-saving, increase risks of hemorrhage, infection, uterine complications, and reduced maternal quality of life. This study aimed to analyze emergency C-sections by Robson classification and identify associated risk factors in groups 1, 2a, 3, and 4a. Materials and methods: A retrospective case-control study was conducted using 886 medical records (443 emergency C-sections and 443 vaginal deliveries) from 2021–2023. Data were analyzed with IBM SPSS 24.0, and binary logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI). Results: Robson 2a was the most frequent category (43.8%), followed by 4a (25.7%), 1 (20.1%), and 3 (10.4%). Significant risk factors for emergency C-section included maternal age (p<0.001), early cervical dilation (<5 cm) at labor diagnosis (OR 3.54), abnormal CTG, pre-eclampsia, PROM, amniotomy, infertility, and malposition. Multivariate analysis showed PROM (aOR 14.66), amniotomy (aOR 6.85), fetal weight ≥4000 g (aOR 4.07), and maternal age (aOR 1.48) as key predictors. Conclusions: Emergency C-sections were most common in Robson group 2a. Major contributing factors included PROM, amniotomy, maternal age, macrosomia, and abnormal labor patterns. Targeted interventions to manage these risk factors could reduce unnecessary emergency C-sections.