Background: Thyroid nodules (TNs) are a common clinical issue, and their prevalence has been increasing over the last 2 decades [1] due to the widespread use of ultrasound (US) imaging. More than 50% of TNs are detected with US examination In the general population, while only 3–7% are detected with palpation [2]. Nodular goiter is the most common cause of thyroid disease in Mongolia, as in other countries. Recent guidelines suggest that a nodule without clinical symptoms should be treated with watchful waiting; however, some patients require treatment because of cosmetic problems or symptoms. There are several treatment options, but neither is perfect. The main treatment of the disease is still the traditional surgical resection. it still carries a 2–10% prevalence of complications, such as neck scarring, hypothyroidism, transient or definitive postoperative hypoparathyroidism, recurrent laryngeal nerve injury, and the recognized risks associated with general anesthesia [3,4]. Minimally invasive alternatives have been explored. Laser ablation, microwave ablation, HIFU, and radiofrequency ablation (RFA) are safe and effective techniques for the treatment of nodular goiter. it is possible to treat small nodules early and enlarge them before surgical intervention is indicated. We have introduced a new method of RFA treatment (2019) in our country. Purpose: To assess the effectiveness of radiofrequency ablation (RFA) for cystic thyroid nodules. Material and Method: This retrospective study was approved by the Research Ethics Committee of the Mongolian National University of Medical Sciences and informed consent was obtained from all patients before RFA. The study was conducted from 9th Jan 2019 to 15th Oct 2021, 485 nodules from 183 patients (M:F=9:174; mean age±SD=46.3±11.4 years) who met the eligibility criteria and provided written informed consent were enrolled at the First Central Hospital of Mongolia. Nodules were assessed pre-treatment and at 1, 3, 6, 12, and 24 months post-treatment. Nodule volume were recorded at each time point.
The primary endpoint was the volume reduction ratio (percentage) at 1, 3, 6, 12, and 24 months follow-up. Results: For the primary outcome of nodule volume reduction, the absolute volume reduction at the 24-month follow-up was 45 (77.6%). Completely destroyed 10 (17.2%), volume increased by 3 (5.2%) (table. 3). The median volume reductions at the 1, 3, 6, 12, and 24-months follow-ups were 34.9%, 61.0%, 74.9%, 83.3% and 74.0% respectively. Median volume statistically decreased by a significant p=0.0001. At 3 months follow up after RFA, the nodules decreased most. All study subjects recovered without sequelae. Therefore, no patient experienced a life-threatening or delayed complication during the follow-up. Conclusion Our study demonstrates that RFA is a safe and effective treatment for cystic thyroid nodules. Advantages of RFA include no surgical scars or general anesthesia, low complication rates, and avoiding lifelong thyroid hormone replacement.

Introduction: Hepatocellular carcinoma incidence and mortality per 100,000 population in Mongolia is the highest in the world. The individual’s genetic factors and new genetic changes are considered an important effect on the origin and development cancer. We aimed to investigate whether p53R72P polymorphisms were associated with the risk of hepatocellular carcinoma in Mongolian patients. Material and Method: p53R72P polymorphisms were evaluated in 80 controls and 38 HCC cases using a PCRrestriction fragment length polymorphism assay. Results: The mean age was 58.5±13.6 years in the case group and 63.2±8.1 years in the control group. Hepatocellular carcinoma is most common in 50-59 (n=14, 36.8%) and 60-69 (n=14, 36.8%) ages. Of the HCC group, 4 (10.8%) were diagnosed with tumor at stage II, 23 (62.2%) at stage III, and 11 (27%) at stage IV.
The results revealed that the heterozygous (Arg/Pro (PR)) genotype of p53R72P increased statistically significant the risk of hepatocellular carcinoma (OR=4.222, 95% CI 1.669-10.684) compared to the wildtype (R/R) genotype. (p=0.002). Moreover, the homozygous (Pro/Pro (P/P)) genotype of p53R72P increased the risk of carcinoma (OR=1.333, 95% CI 0.414-4.299) but not statistically significant. (p=0.63). Heterozygous (Arg/Pro (PR)) genotype of p53R72P in the tumor tissue was associated with a statistically significant (OR=3.3, 95% CI 1.274-8.57) increase in the risk of HCC (p=0.014). Pro/Pro (PP) genotype increased the risk of the carcinoma by 2.4 times (OR=2.44, 95% CI 0.865-6.908), but it was not significant. (p=0.092). Pro/Pro (PP) genotype of p53R72P in the tumor tissue compared to normal tissue of a case group increased the risk of cancer by 1.8 times (OR=1.833, 95% CI 0.472- 7.126), which was not statistically significant (p=0.382). Conclusion Taken together, Heterozygous (Arg/Pro (PR)) genotype of p53R72P increases the risk of hepatocellular carcinoma in Mongolians. Further studies with larger populations are needed to confirm these results.

Background: Headache disorders are most prevalent public-health problem. Worldwide, among the adults 46% suffer from primary headache, where the migraine presents 11% and tension type headache (TTH) presents 25%. Recently, one type of the primary headache, medication overuse headache tends to increase. Nowadays, there is no sufficient study about primary headache in Mongolia. So that, it is necessary to investigate prevalence, clinical type and risk factors of the primary headache. Purpose: To study prevalence and risk factors of primary headache in Mongolia. Materials and Methods: This cross-sectional study was carried out from June to November of 2017. Participants aged 18-65 years old were randomly selected from four provinces and three districts of Ulaanbaatar city. The diagnosis of headache was made using the International Classification of Headache Disorders-3 beta. Statistical analysis was performed on SPSS-23 program. Results: A total of 2043 participants (812 men and 1231 women) were reviewed. The participant’s average age was 38.6±13.4years. 1350 (66.1%) participants reported recurrent headache within the last 1 year. Of the total study population, the prevalence rate of primary headache was 1305 (63.9%). Number of people who suffered from migraine was 494 (24.2%), significantly greater in female than male participants (p=0.0001), with most frequent attacks at age 26-45 years. The risk of migraine associated with sex, education and family history (p=0.001). 592 (29.0%) of participants had TTH, mean age of them was 37.7±5.24, significant high rate in female than men, risk of TTH depends on education and job. The medication overuse headache was diagnosed at 116 (5.7%), 29.4% in men and 70.5% in women with average of 45.6±11.4 and 43±12.7 respectively. Among the participants 38.6% used medications, 28% people had one drug, 8.5% two drugs and 2% used three or more drugs. Use of non-steroid anti-inflammatory drugs (NSAID) made up major percent in headache patients. Increased frequency of medication and multidrug affected to medication overuse headache (p=0.008). Conclusion More than half of studied population had primary headache. Migraine was in 24.2%, TTH in 29.0% of people, and associated with sex, education and family history. Use of non-steroid anti-inflammatory drugs made up major percent in headache patients.

Background: A 2018 study on the global burden of disease, accidents, and risk factors reported that 1.6 million peo ple died in 2017 due to household air pollution. Poor indoor air quality has been highlighted as a contributing factor to respiratory diseases, cardiovascular conditions, and exacerbation of asthma and allergies. A 2019 study estimated that long-term exposure to fine particulate matter (PM2.5) with a diameter of 2.5 micrometers or less reduces average life expectancy by 1.8 years, with more severe effects in highly polluted regions. Additionally, a study by Miller et al. (2007) found that prolonged exposure to PM2.5 increases the risk of cardiovascular diseases, particularly among women. Direct measurement devices are highly effective in determining indoor PM2.5 concentrations, identifying sources of pollution, tracking pollutant dispersion, and monitoring temporal variations. Studies suggest that direct measurement is an accurate, cost-effective method that provides detailed data suitable for local conditions. Aim: To investigate the indoor air quality of houses and apartments in Darkhan city during the winter season using the Purple Air monitoring device. Materials and Methods: A cross-sectional study was conducted with a targeted sample of 128 households in Darkhan city. The study examined factors such as stove type, type of coal used, annual and daily coal consumption, frequency of heating, and chimney sealing conditions. To collect data, the Purple Air monitoring device was installed in each house hold for a month, after which it was retrieved. During retrieval, participants completed a questionnaire. The questionnaire consisted of 55 questions across 7 pages at the time of device installation and 25 questions across 3 pages at the time of device retrieval. The collected data was analyzed using SPSS 25.0. Results: A total of 128 households in Darkhan city participated in the study. The average duration of residence in the current home was 9.5 years, with no statistically significant variation. The distribution of housing types was as follows: traditional Mongolian gers (40.6%), houses (39.1%), and apartments (20.3%). The 24-hour average PM2.5 concentration was highest in gers (70.9 μg/m³), followed by houses (46.8 μg/m³) and apartments (22.8 μg/m³), with a statistically significant difference (p=0.0001). PM2.5 levels were most variable in gers, followed by houses and then apartments. House holds using central heating (apartments) had an average 24-hour PM2.5 concentration of 22.8 μg/m³, whereas households using stoves (gers and houses) had a significantly higher concentration of 59.4 μg/m³ (p=0.0001). However, there was no statistically significant difference between traditional and improved stoves. Among study participants, 21.4% reported that someone in their household smoked indoors. Additionally, 86.5% regularly burned incense, candles, or herbs, while 99.2% did not use an air purifier. Conclusion The indoor particulate matter concentration in houses and gers in Darkhan was 59.4μг/m3. Variations in stove types, poor chimney sealing limited space, and frequent gaps and cracks contribute to increased spread of indoor air pollutants.