Purpose: To evaluate colorectal cancer localization in preoperative patients in Mongolia using CECTand endoscopyMaterials and Methods: Totally 10575 optic colonoscopy examinations were performed at UlaanbaatarSongdo Hospital between January 2009 and December 2012. From these examinations, colorectal cancerwas detected in 218 cases; from them 175 had CT examinations. From patients with CT examinations,111 underwent surgery at UBSH, National Cancer Center, State Central Hospital. (64MDCT SiemensSomatom). Only 86 patients with colorectal carcinoma proved by endoscopic or operative pathologywere included into this study. We retrospectively reviewed from the UBSH’ database their preoperativeCT, colonoscopy, surgical and pathohistologic reports using PACSPLUS, OCS operation systems. Toclassify colorectal tumor localization, we divided colon into 8 anatomic parts. The size of tumor wasmeasured as longest dimension visible on CT examination.Results: Study population’s age range was 25-87 age (mean 61.3years ±13.7SD). F: M= 48 (55.8%):38 (44.2%). Urban residents composed 58 (67.4%), rural- 27 (31.4%), foreigner- 1 (1.2%). Tumor sizerange on CT was 0-13 ñì (mean 6.5±2.2 ñì) . Colonoscopy and CT detected colorectal cancer in rectumin 30(34.9%) and 31 (36.1%), in sigmoid colon in 21(24.4%)’’’ and 19(22.1%), in hepatic flexure- 9(10.5%) and 9(10.5%), retrospectively. Double (synchronous) colorectal cancer was detected in 1(1.1%)at colonoscopy and in 2 (2.2%) at CT.Conclusions: The 60-69 age group composed the largest group (38.4%) in colorectal cancer patients,with slight predominance of urban residents over rural and higher female predilection. Sigmoid andrectum are shown to have highest incidence in colorectal cancer. To our best knowledge, it is firstpublication on detection of synchronous colorectal cancer in Mongoliaby both CT and colonoscopy.CT examination is less risky and reliable method to evaluate the entire colonic length in patients withcolorectal cancer suspicion, if observers are skilled in detection of CT signs of colorectal cancer.

Background: Demyelinating disorders are a group of chronic immune-mediated diseases affecting myelinated axons in the central nervous system, which lead to life-long disability. In Mongolia, the last regional prevalence study was conduct ed in 2010. Our study objective is to describe the current prevalence of multiple sclerosis (MS) and other demyelinating disorders in Mongolia. : Aim Materials and Methods: We registered MS, neuromyelitis optica spectrum disease (NMOSD), myelin oligodendrocyte glycoprotein (MOG), and acute disseminated encephalomyelitis (ADEM) cases diagnosed according to the 2017 McDon ald criteria, the 2023 NMOSD diagnostic criteria, International MOGAD Panel proposed criteria. Results: The study was conducted in all tertiary, 7 regional, and 20 provincial hospitals across Mongolia and has collected comprehensive data on 965 patients. The prevalence of total demyelinating disorders was estimated to be 27.2, MS 15.6, NMOSD 5.6, MOG 0.06, and ADEM 0.9 per 100,000 total population, respectively. The prevalence of demyelinating disorders between provinces was compared in order of geographical latitude, from lowest to highest, and was statistically significant. Latitude is associated strongly with the prevalence of demyelinating disorders (p=0.006, 95% CI 14.3-22.4, Pearson correlation=0.603) and moderately with the prevalence of MS (p=0.028, 95% CI 9.39-15.6, Pearson correla tion=0.503). Conclusion In Mongolia, the prevalence of MS has significantly increased and can be considered at medium risk, but still much lower than that in Western countries. The prevalence of NMOSD is almost similar to other Asian countries. An obvious latitude gradient for demyelinating disorders was observed in the Mongolian population.

Purpose: To investigate the outcomes of ROP screening of retinopathy of prematurity (ROP). Methods: This was a prospective of prematurity infants screened ROP from 2020 April 13th to April 28th 2020 and from 2020 June 08 th to June 22th 2020 and prospective cohort study of premature infants with treatment-requiring ROP who received intravitreal injections, laser surgery. Demographic factors, diagnosis and clinical course were recorded. Indirect ophthalmoscopy and Retinal imaging was performed using RetCam (Natus Medical, Pleasanton, CA) and images were taken. Each eye was evaluated by the pediatric ophthalmologist and aimag’s ophthalmologist for the presence or absence of ROP, zone of vascularization, stage, plus disease, and aggressive posterior ROP (AP-ROP). The diagnosis and classification of ROP for this current study were determined by examination using indirect ophthalmoscopy, and treatment plans were determined according to the International Classification for ROP and the Early Treatment for ROP Study (ET-ROP).^2,13 Results: A total of 90 premature infants with BW ≤ 2000g and/or GA ≤ 34 weeks were screened for ROP during the study period. 8 (8.8%) of the 90 infants screened required treatment. The 8 infants who received ROP treatment had a mean GA of 28.5 ± 1.7 weeks, mean BW of 1237.5 ± 125.42g, mean PMA of 36 weeks and mean follow-up time of 2 months. Conclusion After treatment, resolution of ROP was noted in approximately 100 % of the patients who had treatment-requiring ROP.

Background: According to the World Health Organization (WHO), 99 percent of the world’s population is exposed to air that exceeds WHO recommendations, with low- and middle-income countries being the most affected. The main causes of indoor air pollution include human activities such as fuel burning, cooking, cleaning, and smoking; housing character istics such as walls, floors, ceilings, and furniture; ventilation; and outdoor air pollution. Aim : To assess PM1 and PM10 concentrations in 120 selected households in Ulaanbaatar. Materials and Methods : Indoor PM1 and PM10 concentrations were measured using Purple Air real-time sensors in randomly selected Ulaanbaatar households between October 2023 and January 2024. Supplementary data on factors af fecting the PM2.5 concentration were collected via questionnaires. Each measurement was taken in 10-minute intervals, yielding 51,309 data for analysis. Results : PM1 concentrations were measured at 55.5±53.2 μg/m³ in gers, 54.9 ± 46.7 μg/m³ in houses, and 31.6±40.1 μg/ m³ in apartments (p<0.001) and measuring PM10 concentrations were 110.6±108.6 μg/m³ in gers, 110.6±96.7 μg/m³ in houses, and 62.2±83.0 μg/m³ in apartments (p<0.001) When considering the concentration of PM1, PM10 by heating type, PM1 was 55.3±50.1 μg/m³ and PM10 was 110.6±103.0 μg/m³ in households with stoves and furnaces, and PM1 was 31.6±40.1 μg/m³ and PM10 was 62.2±83.0 μg/m³ in households connected to the central heating system (p<0.001). Regarding the months of measurement, the highest concentration was observed in December 2023, at 77.1±94.1 μg/ m³. The highest concentrations for both PM₁ and PM₁₀ were recorded in January 2024, at PM₁: 64.8±55.1 μg/m³, PM₁₀: 131.4±116.0 μg/m³. Conclusion 1. Indoor PM10 concentrations in residential environments in Ulaanbaatar city were within the MNS4585:2016 Air Quality Standard, however, it was exceeded the WHO air quality guidelines, indicating an excessive risk of increas ing morbidity and mortality among the population. 2. Indoor PM1 and PM10 concentrations in residential environments in Ulaanbaatar varies depending on location, type of housing, type of heating, and month of measurement.