Background: Alloxan is a chemical compound commonly used in experimental animal models of diabetes. In 1943, Shaw Dunn and Mc- Letchie reported that alloxan causes specific necrosis of pancreatic β-cells in experimental animals, which led to the study of alloxan in relation to diabetes. In this study, we evaluated the structural changes in the pancreatic tissue of diabetic mice induced by alloxan. Aim: To study the structural changes in the pancreatic tissue of diabetic mice induced by alloxan. Materials and Methods: According to the protocol for establishing a diabetic model, alloxan monohydrate was injected intraperitoneally into 6- to 8-week-old C57BL/6 mice to develop a diabetic model and evaluate the structure of pancreatic tissue. Results: Alloxan induced severe degenerative changes in the centers of the pancreatic islets of mice in the diabetic group. The islet shape was irregular, and the central part was relatively sparse; dead (karyolysis) cells were observed. In the exocrine part of the pancreas, the acinar structure was preserved; the nuclei of acinar cells were stained bright blue. The plasma-particle ratio of some acinar cells was lost, the plasma contained vacuoles, and the interstitial spaces were enlarged and appeared pale. On the 7th day of the experiment, the positive expression of β-cells in the pancreatic islets of mice in the diabetic group was reduced compared to the control group, and a necrotic area was observed. On the 28th day, the positive expression of β-cells was visible in the central part of the islet. When the qualitative characteristics of the positively stained cells of the islets of Langerhans were converted into quantitative values, the percentage of the area of insulin-positive stained cells was 13.37% ± 0.89% in the control group and 6.01% ± 0.39% in the diabetic group. The percentage of glucagon-positive stained cells in the control group was 15.27% ± 1.11%, and in the diabetic group was 5.01% ± 0.58%. The islet area of the pancreatic islets of Langerhans in the diabetic group was observed to be increased compared to the control group. This is thought to be due to the swelling of the islet cells and the formation of empty spaces created by necrotic cells. Conclusion The results of the functional assay showed that glucose- dependent insulin secretion was still active after 28 days of the experiment. Alloxan-induced necrosis and apoptosis reduced the percentage of insulin- and glucagon-positive cells in the islets of Langerhans.

Background: The skin barrier serves as the primary defense against environmental factors. Mongolia’s extreme climate conditions may contribute to skin barrier impairment, increased trans-epidermal water loss (TEWL), and decreased skin moisture. Objective: To determine and compare skin moisture, TEWL, and skin pH levels in children. Methods: A cross-sectional study was conducted in June 2023 with 104 relatively healthy children selected through random sampling. Skin physiological parameters, including skin moisture, skin pH and TEWL were measured following the EEMCO (European Group on Efficacy Measurement of Cosmetics and Other Topical Products) guidelines using the Multi Skin Test MC750 device (Courage+Khazaka Electronics, Germany) at nine different sites. Data analysis was performed using Microsoft Excel and Stata-14 software. Results: Among the participants, 51.9% (n=54) reported having dry skin (p<0.0001). Additionally, 64.5% (n=67) used moisturizers, but their usage did not show a statistically significant difference in skin moisture (p=0.929), skin pH (p=0.378), or TEWL (p=0.332). 14.42% (n=15) had extremely dry skin, while 85.58% (n=89) had dry skin, with no participants falling within the normal skin moisture range. TEWL showed a moderate inverse correlation with age (r=-0.331, p=0.0006). When analyzed by age groups, skin moisture (p=0.023) and TEWL (p=0.038) differed significantly between groups. Conclusion Skin moisture and TEWL significantly differ across age groups. Given that all participants had dry skin, moisturization is crucial. Mongolia’s extreme climate is likely a key contributing factor to childhood skin dryness.

Background: Double-lumen tubes (DLTs) are widely used in thoracic surgery to achieve one-lung ventilation. International recommendations suggest tube size selection based on height and sex (39 41 Fr for males ≥160 cm, 35–37 Fr for females ≥150 cm). However, in Mongolian practice, applying these standards often leads to oversized tube use and related complications. Objective: To compare international standards for DLT size selection with body height and sex in Mongolian patients. 10 Methods: A cross-sectional study was conducted among patients who underwent esophagectomy with left-sided DLT placement at the National Cancer Center of Mongolia between 2018 and 2023. Data included age, sex, height, and DLT size. Statistical analysis was performed using chi-square and t-tests, with p < 0.05 considered significant. Results: A total of 211 patients were analyzed (58.8% male, 41.2% female). Among males, 170 cm patients received 37 Fr in 90% of cases (p < 0.001). Among females, 160 cm patients either 35 Fr or 37 Fr (p < 0.001). Tube size also differed significantly by sex (p < 0.001): 68.5% of males received 37 Fr, while 83.9% of females received 35 Fr. Conclusion In Mongolian clinical practice, DLT sizes are generally chosen smaller than those recommended by international standards, based on sex and height. All patients in the study achieved successful one-lung ventilation and favorable surgical conditions, indicating that international standards may not be fully applicable to the Mongolian population. Moreover, the study highlights that while DLT size selection correlates strongly with height in males, the association is weaker in females. Therefore, reliance solely on height and sex may be insufficient, and additional biometric and anatomical parameters should be considered for optimal tube selection

Background: Lung cancer remains the leading cause of cancer-related mortality worldwide, accounting for approximately 1.8 million deaths annually and representing 18% of all cancer deaths¹. According to the GLOBOCAN 2024 report, 2.4 million new cases were registered globally, ranking second after breast cancer². Non-small cell lung cancer (NSCLC) constitutes 85% of lung cancer cases, with adenocarcinoma being the most common subtype³. The objective of this study is to map the prevalence of HER2 activation and mutations in EGFR, EML4-ALK, ROS1, BRAF, and KRAS genes among lung cancer patients in Mongolia, and to evaluate their correlations with clinical and morphological parameters (age, sex, smoking status, stage, and morphology). Aim: To determine the distribution pattern of HER2 activation and EGFR, EML-ALK, ROS1, BRAF, KRAS gene mutations among patients with lung cancer in Mongolia, and to evaluate their associations with clinical and morphological characteristics. Materials and Methods: A retrospective study was conducted using archived materials from lung cancer patients at the Clinical Pathology, Molecular Genetics, and Pathology Laboratories of the National Cancer Center of Mongolia, covering the period from 2019 to June 2025. DNA Extraction from Tumor Tissue: Formalin-fixed paraffin-embedded (FFPE) tissue blocks from patients diagnosed with lung cancer, stored in the pathology department archives, were selected for the study. Sections of 5–10 μm thickness were cut, mounted on glass slides, stained with hematoxylin and eosin (H&E), and reviewed by a pathologist. Areas containing ≥20–30% tumor cells were identified and macro-dissected for analysis. Real-Time PCR Assay for Detection of EGFR/BRAF/KRAS/EML4-ALK/ROS1 Mutations: EGFR mutation detection was performed using the PANAMutyper™ EGFR Mutation Detection Kit (Panagene, Daejeon, South Korea) according to the manufacturer’s instructions. PCR reactions were carried out on a compatible instrument (Roche LightCycler 480, Germany) as recommended by the manufacturer. Statistical analysis was performed using Prisma-10 software. Results: A total of 282 lung cancer cases were included in the study. EGFR mutations were detected in 44% of cases and were absent in 56%. No significant age-related differences were observed (p=0.2636); however, EGFR mutations were significantly more frequent in females (36.6% vs. 19.6%, p=0.0019). No statistically significant differences were found across disease stage, T, N, or M classifications (p>0.05). No association was identified between smoking status and EGFR mutations (p=0.4178). Morphologically, EGFR mutations were significantly more prevalent in adenocarcinoma (54.83%) compared to squamous cell carcinoma (SCC) (31.8%; p=0.002). Of the 282 cases, adenocarcinoma accounted for 155 (54.9%) and SCC for 116 (41.1%). Overall, EGFR mutations were positive in 43.97% of cases, with a higher prevalence in adenocarcinoma (24.82%) than in SCC (13.1%). By exon: - Exon 18 mutations were detected in 6% of cases, predominantly in adenocarcinoma (6%, 4.25%). - Exon 19 mutations occurred in 8.15% and are associated with sensitivity to targeted therapy. - Exon 20 mutations were found in 3.19%, with the T790M resistance variant in 1.77%. - Exon 21 mutations were observed in 9.57%, more common in adenocarcinoma (9.57%) than in SCC (3.19%). Survival analysis stratified by stage at diagnosis showed significantly longer median survival in early-stage patients (18.6 months). Kaplan-Meier curve comparison, log-rank test, and hazard ratio calculations confirmed statistically significant differences (p < 0.05), indicating that disease stage is a key prognostic factor. Conclusion The study findings reveal a high prevalence of EGFR mutations among Mongolian patients with lung adenocarcinoma, underscoring the need for widespread implementation of targeted therapy (EGFR-TKIs). In contrast, mutation rates were lower in SCC and other morphological subtypes, highlighting the importance of investigating alternative molecular markers in these subgroups.

Background: Globally, gastric cancer accounts for 1,089,000 new cases and 769,000 deaths annually, ranking fifth in overall cancer incidence and third in cancer-related mortality. The aim to determine HER2 expression in patients with gastric cancer and to evaluate its correlation with clinical and immunological biomarkers, as well as the need for further laboratory diagnostics. Aim: To determine HER2 expression in patients with gastric cancer and to evaluate its association with clinical and immunological biomarkers, as well as the potential need for further laboratory diagnostics. Materials and Methods: A retrospective study was conducted using archived materials from patients with gastric cancer at the Clinical Pathology, Molecular Genetics, and Pathology Laboratories of the National Cancer Center of Mongolia, covering the period from 2019 to June 2025. HER2 protein expression in tumor tissue was assessed using immunohistochemistry (IHC), and chromogenic in situ hybridization (CISH-HER2) was employed to confirm gene amplification. Statistical analysis was performed using the Prisma-10 software. Results: In our study, among 210 cases of gastric cancer evaluated by IHC for HER2, 46 (21.9%) were HER2-positive and 164 (78.1%) were HER2-negative. When comparing patients with gastric cancer stratified into HER2 1+ (negative) and HER2 3+ (positive) groups, no statistically significant differences (p < 0.05) were observed in age, sex, tumor location (surgically resected tissue), morphology, or disease stage. However, a higher proportion of males was noted in the HER2 3+ group (80.9%), though this did not reach statistical significance (p = 0.0879). Significant associations were found with tumor markers. Elevated serum CA-72-4 (>5 ng/mL) was more frequent in the HER2 3+ group (58.8%; p = 0.0069). In contrast, elevated CA-19-9 (>35 U/mL) was more common in the HER2 1+ group (93.5%; p = 0.0117), and elevated CEA (>6.9 U/mL) was also predominant in the HER2 1+ group (90.6%; p = 0.002). These findings suggest that HER2 3+ status predominates in cases with elevated CA-72-4, which may influence diagnostic strategies and HER2-targeted therapies (e.g., trastuzumab). Conversely, elevated CA-19-9 and CEA were more associated with HER2 1+ status, indicating a need for further detailed investigation of these markers in relation to HER2 expression. In patients evaluated by CISH for HER2 expression, stratification into HER2-positive and HER2-negative groups revealed no statistically significant differences (p < 0.05) in age, sex, tumor location, morphology, stage, or serum tumor markers (CA-72-4, CA-19-9, CEA). This suggests that HER2 status (positive/negative) may be independent of these variables. Although HER2 positivity was higher in poorly differentiated tumors (48% vs. 30.6% negative; p=0.1414) and in stage IV disease (50% vs. 39.3% negative; p=0.2607), these differences were not statistically significant. Elevated serum markers (CA-72-4, CA-19-9, CEA) were observed but showed no significant correlation with HER2 status. Conclusion Determining the molecular profile of gastric cancer patients can significantly contribute to refining clinical diagnosis, developing treatment strategies, enhancing therapeutic outcomes, and improving patients’ quality of life.

Background: Studying the human embryonic and fetal organ systems development patterns and determining their quantitative indicators is of scientific and practical importance in medicine and health in every nation.
Distortions and pathologies during the development of the embryo are the causes of congenital disabilities. Among the congenital malformations, facial malformations are the 3rd place, including cleft lip and palate in 70% and Srouzon's syndrome in 30%. In addition, abnormalities due to changes in the size, shape, and position of the jaw are also mentioned in the 2021.04.21 issue of Morphology magazine in the study "Morphometric parameters of the bones of the skull and face during the development of newborns and fetuses". In our country, Ariuntuul G (2005) determined that cleft lip and cleft palate occur at 0.76/1000 or 1 in 1314 live births, while Ayanga G (2012) found that it occurs at 1 in 1072 live births or 0.93/1000. Moreover, the eye cup dimensions of Mongolian fetuses aged 16 36 weeks have a positive linear relationship with the gestational age determined using ultrasound by Nandintsetseg B (2015) et al. Compared with the other countries, the eyecup is slightly wider, and the outer edge distance is similar, whereas the inner edge distance is shorter. Purpose: To summarize research work and determine the embryonic development of bones involved in the formation of the face and facial parts, the period of bone formation, the point of ossification, and the period of formation. Methods: During fetal development, human organ systems grow and develop at different rates but in a particular relationship. This feature of growth and development is also clearly observed in the structure of the head and facial bones, and the results of researchers who have studied this aspect are selected in the articles. Results: Embryonic and fetal development of bone are clinically significant not only from the point of view of its morphogenesis but also from the point of view of congenital disabilities. Conclusion In the analysis of the sources, most of the works on the prenatal period of the development of the same body have studied the development of specific structures of the face and facial area, such as the palatine bones and nasal bones, or have generally covered the development of particular systems in the embryo and fetus, and face, there are relatively few works that show the entire dynamics of growth and development of facial bones.

BACKGROUND OF STUDY: According to WHO report estimation, 76.3 million people have been diagnosed with disorder related to alcohol use which has been root cause for over 60 types of disease in the world.1 Smoking causes death to4 million people every year, 11 people every day and 6 every minute. This number is estimated to double reaching 10 million by 2030.2 The study conducted by the ‘World Vision Mongolia’ international organization and the Anti-alcoholism and Drug Association of the Ministry of Justice show 76% of all teenagers has drunk alcohol to some extent. AIMS: To determine alcohol, tobacco and psychoactive drug use by school teenagers of Sukhbaatar district in Ulaanbaatar MATERIAL AND METHODOLOGY: The survey on inquiry of alcohol, tobacco and psychoactive drug use (ASSIST) was conducted among a total of randomly selected 800 (374 boys, 426 girls) students of 8-12th grade from 7 secondary schools of Sukhbaatar district. Statistical data was put into Microsoft office applications (excel, word) and processed by SPSS application with 95% of probability of information and 5.0% of trust level. RESULT OF STUDY: Out of all respondents 32% (256) use tobacco, 43.8% (350)alcoholic drinks, 2.6% (21)cannabis,1.1% (9) cocaine, 1.5% (12) amphetamine, 3%(24)volatile substance, 4.3% (34)sedative and tranquilizer drug, 0.6% (5)hallucinogenic drug, 0.5% (4) opioid, and 0.1% (1) uses other types of drug. Among the survey participants, there are a total of 214 teenagers (in duplicated number) who need short-term action and 2 teenagers who are smoker and need intensive treatment. CONCLUSION: Among total teenagers, the survey participants, 1 in 3 used tobacco, 1 in 2 alcoholic drinks and 1 in 7 used psychoactive drug. Male students smoke twice more than female students and there is no difference in use of alcoholic drink in both sexes. The alcohol and tobacco use among teenagers at the age of 12-18 who participated in the survey showed that they use more when they grow older. 1 in 4 students of all participants belongs to a group with average risk and needs intensive treatment.

BACKGROUND: Toll like receptors (TLRs) are a class of proteins that key role in the innate immune system. TLR7 is expressed on monocytes, macrophages and dendritic cells, T cell, B cell and eosinophiles. TLR7, originally identified as recognizing imidaquinoline, loxibrine, broprimine and ssRNA, ssRNA viruses such as vesicular stomatitis virus, influenza A virus and human immunodefiency virus. It is known that virus ssRNA affects signaling molecule of IFN-y. Objective: To determine gene and protein activation of IFN-y signal transduction by TLR7 ligand in the endothelial cells. MATERIAL: In study we used mouse aortic linear endothelial cell which is cultured (END-D) in 5% heat- inactivated fetal calf serum (FCS), medium (DMEM) containing antibiotic mix(penicillin G, streptomycin, amphotericin B) at 37°C (5% CO2). Endothelial cells treated with synthetic IFN-γ and imiquimodligands, then the NO (nitric oxide) concentration in the supernatant is determined by Griess reagent. Endothelial cells are cultured in 6 well cell culture plate and in each well 2*104cells are expected to be grown for 24 hours of culture. Then, the cells are treated with synthetic IFN-γ and имиквимод ligand for 6 hours and the NO signaling gene activation iNOS mRNA expression which is induced by IFN-γ is determined by RT-qPCR. Endothelial cells are cultured in 12 well cell culture plate and in each well 2*104 cells are expected to be grown for 18 hours of culture. Then, the cells are treated with synthetic IFN-γ and imiquimodligands for 24 hours and the NO signaling protein iNOS expression which is induced by IFN-γ is determined by western blotting. The experiment was conducted as representation mean of at least three test results. The difference between statistical probabilities is determined by the “Students” t test. The p<0.01 value is assumed to be statistically different. RESULTS: TLR7 ligand imiquimodaugmented interferon gamma induced nitric oxide production TLR7 ligand imiquimodincreased interferon gamma induced iNOS mRNA gene expression. TLR7 ilgand imiquimodup-regulated interferon gamma induced iNOS protein expression. CONCLUSIONS: TLR7 ligand imiquimod augments IFN-γ signaling in the endothelial cells. This synergistic effect has revealed in the levels of gene and protein expression.

Introduction: The aim of this research project is to elucidate the crosstalk of innate and adaptive immune reactions against the DNA containing bacteria. : This study held in the Core laboratory, Science Technology Center, Mongolian National University of Medical Sciences (MNUMS). Murine aortal endothelial cells, END-D cultured and the cell viability checked by MTT assay. In addition, the NO production, protein and gene expression studied by Griess Reagent assay, R.T-PCR and immunoblotting, respectively. Results: 0.1µM, 1µM and 10µM of TLR9 ligand exhibited no cytotoxic action against the cells by MTT assay. IFN-ү alone induced NO production in END-D cells. In the other hand, TLR9 ligand at 0.1µM, 1µM and 10µM up-regulated IFN-ү induced NO production in dose dependent manner. RTPCR results exhibit that TLR9 ligand up regulates iNOS mRNA. Immunoblotting analysis showed the enhanced iNOS protein expression and phosphorylation of STAT1 in cells pre-treated with TLR9 ligand. Discussion: We have demonstrated CpG DNA, TLR9 ligand, up-regulates IFN-ү induced NO via enhanced IFN-ү signaling. The result of Western Blotting and RT-PCR support the up-regulation of NO. CpG DNA can be used as agent against virus and bacteria. Further research need to be conducted. Conclusion TLR9 ligand, CpG DNA up-regulates IFN-ү induced NO production in time and dose dependent manner. TLR9 ligand augments the expression of iNOS mRNA and STAT1 phosphorylation in response to IFN-ү.

There are a lot of influencing factors of facial nerve palsy; experts believe that is most likely caused by a Virus (54%) and Bacterial infections. Noninfectious causes of facial nerve palsy induce tumors (28%) and less commonly influences head trauma (18%). The retrospective analysis of WHO, in 2012. There are some cases of postoperative complication in middle ear surgery is facial nerve palsy and the total recovery outcome of function was not good. From 2013 to 2016 in EMJJ hospital, Mongolia, we enrolled 16 cases with facial nerve damaged in intratympanic canal but we could not recruit some patients with facial palsy over 6 months. Each subject was tested with pure tone test, ABR, Tympanometry. These were performed for the detection of hearing loss after Temporal bone injury. Then we also investigated location of facial nerve damages of patients by MRI and CT before reconstructive surgery. After that surgery, all patients were given corticosteroid treatment (20mg/day) and physical therapy performed such as acupuncture for a week. Study results revealed that 6 cases after 18 days, 2 cases after 30 days, 1 patient after 45 days of reconstructive surgery regained good symmetry. Therefore, we considered that, postoperative treatments like physical therapy with B12, steroid had good benefits for operation result and to shorten the recovery time. There was a patient who had damaged facial nerve in the tympanic segment during Mastoidectomy. In that case, we performed cable nerve grafting using the r.auricularismagnium but we could not recover facial nerve function. Traumatic facial nerve paralysis is the second most common type. We discussed that performing reconstruction surgery within first 3 months after intratemporal facial nerve injury is extremely desirable and more effective. In our opinion, nerve recovery might be not successfully cause of injured myelin sheet of facial nerve during middle ear surgery.