Background: A 2024 study by the National Statistical Office of Mongolia indicate an incidence rate of 38.8 per 100 000 population, with a total of 8169 new cancer cases diagnosed, of which 16.2% are gastric cancers. Notably, 64.4% of these diagnoses are made at advanced stages.2 Surgical intervention remains one of the most effective treatments for gastric cancer. Early-stage surgery confers a 5-year survival rate of 60-80%, whereas late-stage diagnosis reduces this to 18-50%.5 This study aims to investigate the causes, types, and contributing factors of postgastrectomy anemia in patients undergoing surgery for gastric cancer in Mongolia, where no prior study has been conducted on this topic. Methods: This retrospective study analyzed all patients who underwent gastric cancer surgery at the National Cancer Center of Mongolia from 2022 to 2024. Data on demographics, lifestyle factors, clinical signs of anemia, and comorbidities were collected from medical records and confirmed by direct examination. Results: A total of 788 patients who underwent surgery for gastric cancer were included in the study, of whom 70.5% were male and 29.5% female, aged 22–70 years (mean age 46 years). Among the total cases, 461 patients underwent total gastrectomy, 128 had distal gastrectomy with gastrojejunal anastomosis, 39 underwent partial gastrectomy, 3 had gastrectomy with duodenal anastomosis, 5 underwent gastrectomy with esophagogastric anastomosis, and 6 underwent bypass procedures. Conclusions Postoperative monitoring after gastric surgery was insufficient, and there was a tendency for anemia to progress.

Background: The average age at menarche (AAM) among girls is influenced by various factors, including the socioeconomic status of the country, geographical location, and anthropometric characteristics. In Mongolia, limited research has been conducted on this topic Aim: This study aimed to compare the mean age at menarche among girls living in Bayanzürkh District of Ulaanbaatar and those in Uvs Province. Materials and Methods: A cross-sectional study was conducted between April and June 2025. The study participants included schoolgirls aged 8 years and older from general education schools located in Bayanzürkh District and Uvs Province. Statistical analyses were performed using R version 4.5.1 (RStudio 2025.05.1-513) Results: A total of 486 girls participated in the study. The mean age at menarche among the participants was 12.23±1.29 years. The mean age at menarche among girls aged 8–18 years in Bayanzürkh District was 11.84±1.19 years, while that among girls aged 8–18 years in Uvs Province was 12.97±1.15 years. Thus, girls in Bayanzürkh District experienced menarche 1.13 years earlier on average than those in Uvs Province. The difference in mean AAM between urban (Ulaanbaatar) and rural (Uvs Province) girls was statistically significant (p<0.0001). Conclusion The mean age at menarche among girls residing in Bayanzürkh District was significantly lower than that of girls living in Uvs Province, indicating a tendency toward earlier onset of menarche in urban areas.

Background: Total knee replacement arthroplasty (TKA) is an essential surgical treatment method performed when the cartilage surfaces of the knee joint undergo irreversible changes due to aging, trauma, genetics, or lifestyle factors. In our country, approximately 2.500 knee replacement surgeries are performed annually. Aim: To investigate the Lysholm scores of patients who underwent total knee replacement arthroplasty and the factors influencing these scores. Materials and Methods: This study was conducted using a retrospective cohort study design. The research was carried out at the First Central Hospital of the country, involving 186 patients who visited the Department of Joint Center from January 2007 to May 2023. Participants provided demographic data, information on comorbidities, alcohol and tobacco use, physical activity, and lifestyle factors through a 56-question survey, divided into two groups. The stability and function of the knee joint were assessed using the Lysholm assessment. A score of 95-100 indicated excellent, 84-94 good, 65-83 moderate, and less than 65 poor. Statistical analysis of the results was performed using SPSS version 26.0. Results: Out of 185 participants, the mean age was 71.83±7.83 years, with 18.9% (n=35) males and 81.1% (n=150) females. The demographic factors such as gender, age group, BMI, and years after surgery were significantly associated with the Lysholm score (p=0.001). Logistic regression analysis identified that age (OR, 2.014; 95% CI, 1.620-1.659; p=0.001), excess weight (OR, 1.328; p=0.001; 95% CI, 0.469-3.765), and years after surgery (OR, 1.194; 95% CI, 0.533- 2.676; p=0.037) were factors influencing the scores Conclusion 037) were factors influencing the scores. Conclusion: The number of years after total knee replacement arthroplasty and patient age significantly affected Lysholm evaluation scores

Background: Liver transplantation (LT) recipients frequently develop complication kidney dysfunction (KD), but the predisposing factors and long-term consequences of KD are not well understood. Post-LT complications that lead to graft failure and patient morbidity/mortality can be generally categorized as vascular, biliary, parenchymal and malignant. Main reasons for our study are to identify complications’ rate for early post-transplant KD and to evaluate the post-LT patients and graft survival rate. Aim: Our aim was to evaluate complications in recipients with early post-transplant KD and to investigate the survival rate after LT. Material and Methods: This study retrospectively and prospectively analyzed the demographic characteristics, preoperative and perioperative clinical parameters, as well as postoperative outcomes of patients who underwent liver transplantation (LT) at the First Central Hospital of Mongolia (FCHM) between September 2011 and December 2024. Renal function was evaluated by estimating the glomerular filtration rate (GFR) using the Cockcroft-Gault creatinine clearance formula at baseline (pre-transplantation) and at 24 hours, 72 hours, 7 days, 14 days, and 28 days following LT. Early and late complications following LT were classified according to the international classification. Ethical approval for the study was obtained at a meeting of the Research Ethics Review Board of the Mongolian National University of Medical Sciences (MNUMS). Results: In our study KD rate was 29.7%. Several factors increased the risk of KD among recipients. Post-LT complications’ related risk factors for KD was high MELD score (OR, 1.11; 95%CI, 1.06-1.16), Child-Turcotte-Pugh scores of B and C (OR, 5.57; 95%CI, 1.27-24.52 and OR, 8.21; 95%CI, 1.87–36.54), comorbidities (OR, 1.92; 95%CI, 1.14-3.23), post-LT acute bleeding (OR, 3.22; 95%CI, 1.22-8.46), early relaparotomy for revision (OR, 3.12; 95%CI, 1.34-7.28 respectively. Additionally, the survival rates for recipients with post-LT KD were 90.7% at 1 year and 81.3% at 3 years. Conclusions 1. Variables like a recipient high age (p<0.001), female gender (p<0.001), elevated liver function scores (p<0.002), comorbidities (p=0.013), severe ascites (p=0.001), preop intensive care (p=0.026) are pre-LT risk factors for post- LT KD. 2. Acute bleeding (p=0.013), early revision (p=0.006) are risk factors for post-LT KD. 3. Early KD in recipients who underwent LT affects both patient survival (Log Rank p=0.522; HR 1.3) and graft survival (Log Rank p=0.457; HR 1.26).

Background: According to the World Health Organization (WHO), oral cancer is one of the most common malignancies of the head and neck region, ranking 16th among all cancers worldwide. Approximately 90% of oral cancers are oral squamous cell carcinomas. The development of this malignancy is influenced by multiple factors, and some genes plays a crucial role in development of the cancer. In recent years, the potential association between lncRNA GSEC and cancer has attracted significant research interest. Aim: This study aimed to investigate some functions of lncRNA GSEC in oral squamous cell carcinoma (OSCC) in vivo experimental model. Materials and Methods: To examine the role of GSEC in the proliferation of human oral cancer cells (CAL27), fifteen healthy 5-week-old BALB/c nude mice were divided into three groups: group Blank (CAL27 cells alone), NC (control si-NC CAL27 cells), and si-GSEC (si-GSEC CAL27 cells). The mice were subcutaneously injected with CAL27 cells alone, control si-NC CAL27 cells and si-GSEC CAL27 cells. Body weight and tumor size of the mice were measured throughout the experiment. On day 13, the mice were sacrificed, tumor tissues were excised and weighed, and the tumor tissues were stained using hematoxylin–eosin (HE) and immunohistochemistry to examine the expression of proliferation-related proteins Ki-67 and PCNA. Results: No significant differences in body weight were observed among the three groups of the mice up to day 13. However, the excised tumors from the si-GSEC CAL27 group were significantly smaller and lighter than those from the si- NC CAL27 and CAL27-only groups (p < 0.001). HE staining showed that tumor tissues in the si-GSEC group had more organized structure, better cellular differentiation, fewer malignant cells, decreased nuclear division, and reduced tumor transformation compared with the other groups. Immunohistochemical analysis revealed that Ki-67 and PCNA expression in tumor tissues was heterogeneously distributed, with higher density in peripheral and poorly differentiated regions, and lower expression in keratinized and necrotic areas. Notably, expression levels of both Ki-67 and PCNA were markedly reduced in the si-GSEC group compared with the other two groups. Conclusion lncRNA GSEC promotes tumor cell proliferation in vivo in oral squamous cell carcinoma.

Background: Since August 2021 in Mongolia, the rapid spread of the SARS-CoV-2 Delta variant among the population coincided with the reopening of all levels of educational institutions, including universities, general education schools, and kindergartens, for in-person learning. Aim: To examine the impact of the measures implemented when school was reopened with in-person learning on COVID-19 morbidity among school children, to assess the overall infection situation in children, and to determine whether any school-based outbreak clusters occurred during the Delta variant surge. Materials and Methods: This study used national data from confirmed COVID-19 cases recorded in the electronic surveillance system between January 1, 2021, and February 28, 2022, including all cases and those among children aged 0-17 years. The 7-day moving average of the proportion of cases among children was calculated, representing the average proportion of pediatric cases during the preceding seven days. Additionally, the study compared the incidence and relative risk (RR) of COVID-19 among children aged 0-17 years at the time of school reopening on September 1, 2021, with those observed during previous outbreaks caused by the SARS-CoV-2 Wuhan, Alpha, and Omicron variants. As vaccination was available only for adolescents aged 12-17 years, the analysis was stratified by three age groups: 0-4, 5-11, and 12-17 years. Results: Throughout the study period, the proportion of COVID-19 cases among children aged 0–17 years nationwide ranged from 0.73% to 5.93% across outbreaks caused by the four SARS-CoV-2 variants (min 0.73%; max 8.57%). The 14-day confirmed case rate per 10,000 population was highest during the Delta (107.57) and Omicron (113.56) variant outbreaks. When comparing age groups, children aged 5–11 years were used as the reference group. During outbreaks, the relative risk for the 12–17-year group was lowest during the wild-type virus wave (RR=0.47) and highest during the Delta wave (RR=0.78). Conclusion During COVID-19 outbreaks, the proportion of pediatric cases (0-17 years) among total cases ranged from 0.73% to 5.93%, consistent with findings from studies conducted in other countries. Overall, infection rates were higher among the 0-4 and 12-17 age groups, with the highest rates among 0-4-year-olds during the Delta variant outbreak. No clustered outbreaks involving six or more cases were reported in school settings. Future studies should focus on assessing the transmission dynamics of respiratory infections among children in both household and school settings, especially during influenza and influenza-like illness outbreaks, to generate evidence for preventive measures against respiratory pathogen transmission.

Background: Studies from other countries have identified multiple contributing factors to renal cell carcinoma (RCC). We conducted this study to investigate the relationship between RCC and certain risk factors among the Mongolian population. Aim: To identify the risk factors for renal cell carcinoma in Mongolian individuals. Material and Methods: This case-control study included 88 patients diagnosed with RCC (confirmed by pathological examination) in the case group. The control group consisted of 88 healthy individuals matched by age and gender. A case-control study design was used. Binary logistic regression analysis was conducted on the questionnaire results from both groups to identify risk factors for RCC through both univariate and multivariate regression analysis. Results: A total of 176 participants were included in the study-88 with RCC and 88 without cancer. Statistically significant associations with RCC were found for hypertension, urinary tract diseases, alcohol consumption, and smoking. Although weight gain appeared to increase the risk for RCC, this was not statistically significant. Conclusion Individuals with hypertension, a history of urinary tract diseases, smokers, and alcohol users are at a higher risk of developing renal cell carcinoma.

Background: Studies on the risk of kidney stone disease by age and gender show that the prevalence varies by countries and regions, particularly influenced by the conutry development, population diet, etc. In our country, research on kidney stones has been scarce over the past two decades. Aim: To study the age and gender characteristics of patients undergoing surgical treatment for kidney stones. Materials and Methods: Data from a total of 551 individuals who underwent surgical treatment at the Urology Department of the First State Central Hospital over a six-month period (01.01.2024-06.01.2024) were analyzed. The age and gender characteristics of patients diagnosed with kidney stones were studied, and logistic regression was used to test the true probabilities. Statistical analysis was performed using SPSS 27 software, with a significance level set at 0.05. Results: Kidney stones were present in 12.5% of surgical patients (n=69), while other urological diseases accounted for 87.5% (n=482). The mean age of patients with kidney stones was 46.46±12.6 years, which is relatively younger compared to patients with other urological surgical conditions (mean age=55.77, SD=16.174). Regarding the prevalence of kidney stones by gender, females accounted for 56.5% and males 43.5%. Considering the gender distribution of all patients receiving urological surgical care, females constituted 19.9% compared to 8.5% for males, nearly double the incidence. According to logistic regression analysis, women had a 1.5-fold higher risk of developing kidney stones compared to men (OR=1.5, 95% CI: 1.5–4.2, p<0.01). The highest prevalence was observed in the 36–55-year age group, while individuals aged over 55 years had a significantly lower risk (OR=0.19, 95% CI: 0.10–0.39, p<0.001). Conclusion Kidney stones were identified in 12.5% of individuals who underwent urological surgery. The majority of hospitalized patients with kidney stones were aged 36–55 years, and women comprised 56.5% of these cases.

Background: In Mongolia, the prevalence of osteoporosis is showing an increasing trend, with Uvs province exhibiting particularly high rates. International studies have primarily focused on calcium intake in adolescents, women during and after menopause, while there is a pressing need for comprehensive baseline research that includes all age groups regard less of gender. Aim: To assess the knowledge and dietary calcium intake among residents aged 18 and above in Uvs province, and to investigate the correlation between calcium knowledge and intake. Materials and Methods: A cross-sectional study was conducted among 330 individuals aged 18 years and older who vis ited the Uvs Province General Hospital. The daily calcium intake was assessed using the Food Frequency Questionnaire developed by the International Osteoporosis Foundation. The data were analyzed using SPSS version 26. Results: A total of 330 participants were included, with a mean age of 44.39 ± 3.93 years. Among them, 33% (n=109) were male and 67% (n=221) were female. Regarding knowledge of calcium, 43% of respondents had low knowledge, 22% had moderate knowledge, and 35% had high knowledge. Concerning daily dietary calcium intake, 43% had a very low intake (<500 mg), 19% had inadequate intake (500–1000 mg), and 38% had adequate intake (>1000 mg). Statistically significant associations were found between calcium knowledge level and gender, education level, calcium supplements, and vitamin D usage (p=0.001). No statistically significant difference was observed between daily calcium intake and the level of knowledge regarding calcium (p = 0.131). Conclusion 1. Among the study participants, 43% had a low level of knowledge about calcium, 22% had a moderate level, and 35% had a high level. 2. Regarding daily dietary calcium intake, 43% of participants had a very low intake, 19% had an insufficient intake, and 38% had an adequate intake. 3. Factors such as gender, educational level, and the use of calcium supplements and vitamin D were found to influence the participants’ level of knowledge about calcium. Therefore, it is necessary to conduct a broader evaluation of calcium intake among the general population, accurately determine calcium consumption, and develop health education programs and recommendations.

Background: During inversion injuries of the ankle joint, the anterior talofibular ligament (ATFL) is the most commonly injured structure. Injuries to the lateral collateral ligaments of the ankle, either in isolation or in combination with injury to the calcaneofibular ligament (CFL), account for approximately 60-65% of all ankle ligament injuries. In recent years, several studies have examined the impact of lateral ankle ligament injuries on lifestyle and overall health. Repeated inversion injuries-particularly those occurring three or more times-can lead to chronic ankle instability (CAI). In the treatment of ankle instability, both open and arthroscopic surgical techniques are widely used internationally. In Mongolia, there is an increasing clinical need to evaluate and compare the outcomes of arthroscopic versus open surgical repair of lateral ankle ligament injuries. This need forms the basis of the current study. Aim: The comparative studies on open vs arthroscopic anterior talofibular ligament (ATFL) repair are limited. This study aimed to compare the early therapeutic efficacy and cost between the traditional open Broström-Gould repair and all-arthroscopic anatomical repair of the ATFL for chronic lateral ankle instability. Materials and Methods: A total of 40 patients with chronic lateral ankle instability undergoing repair of the ATFL be tween September 2024 and February 2025 were retrospectively included with a traditional open surgery (n=10) group and an arthroscopy (n=17) group. The surgery duration, surgical cost, postoperative complications, and the preoperative/postoperative American Orthopaedic Foot & Ankle Society Score (AOFAS) and Karlsson-Peterson score were compared between groups. Results: Compared to the anatomical group, the non-anatomical group had significantly shorter surgery and hospitalization durations. Three months after the operation, the AOFAS and Karlsson scores significantly improved in both groups. Nevertheless, there was no significant difference in the AOFAS and Karlsson scores between groups at both preoperative and postoperative assessments. No significant difference was found in the incidence of postoperative complications between the two groups. Conclusion 1. These results suggest that open Broström-Gould repair and all-arthroscopic anatomical repair of the ATFL have comparable therapeutic efficacy for chronic lateral ankle instability. 2. The arthroscopic surgery had a smaller incision, while the open Broström-Gould had a shorter surgery duration and lower cost.