Background: Although isotretinoin has been confirmed by clinical and experimental studies to be a teratogenic agent that causes fetal developmental abnormalities, its effects on placental development and placental-like extra-embryonic vascularization have not been sufficiently studied. The vascularization of the chorioallantoic membrane is structurally and functionally similar to mammalian placental vascularization, which provided the rationale for conducting this study. Aim: To study the effect of isotretinoin on chorioallantoic membrane vascularization using an in ovo chick embryo model. Materials and Methods: A comparative experimental control study was conducted using fertilized eggs of the same developmental age from Gallus gallus domesticus. At the HH10 embryonic stage, the control group received avian saline, while the experimental group was administered isotretinoin (5 µg/100 µL). Vascularization of the yolk sac and chorioallantoic membrane was evaluated at the macro- and tissue levels at 72 and 120 hours of embryonic development. Vessel branching order, vascular density, and capillary number were compared, and statistical analysis was performed using the Mann-Whitney U test. Result: In the control group, vascularization progressed actively, with abundant formation of third and fourth order vessels, resulting in a dense reticular network. In contrast, the isotretinoin treated group showed delayed vessel branching, a marked reduction in the number of third- and fourth-order vessels, and an overall decrease in vascular density of 40–60%. Histological analysis revealed thinning of the chorioallantoic membrane, loss of tissue layers, and thinning of vascular walls, and the number of capillaries was significantly lower than in the control group (p<0.01). In addition, the development of chorioallantoic membrane vascularization in chick embryos was found to be structurally and developmentally similar to mammalian placental vascularization. Conclusion Isotretinoin was shown to inhibit the development of the chorioallantoic membrane and markedly reduce vascularization and differentiation in an in ovo chick embryo model.

Background: Lumbar disc herniation (LDH) is one of the leading causes of lower back pain and disability, significantly impacting public health and socio-economic well-being. International studies have shown that paraspinal muscle size and structure correlate with age, body mass index (BMI), and spinal disorders. However, comprehensive MRI-based research investigating the correlation between LDH and specific morphometric parameters in Mongolia remains limited. Aim: To evaluate lumbar disc herniation using magnetic resonance imaging (MRI) and compare paraspinal muscle volume and subcutaneous fat thickness. Materials and Methods: An observational retrospective study design was conducted between June 2024 and June 2025 at Asraltmed and Orgil hospitals, enrolling 300 cases selected from 2,840 lumbar spine MRI scans based on inclusion and exclusion criteria. Demographic data (age, sex, BMI) were collected alongside MRI metrics. LDH type, size, location, and severity were evaluated using axial, sagittal, and coronal views across T1WI, T2WI, and STIR/T2FS sequences. Paraspinal muscle cross-sectional area (Multifidus, Erector spinae, Psoas) was measured on axial T1WI and T2WI sequences, while subcutaneous fat thickness was measured on sagittal T2WI sequences. LDH parameters were evaluated in relation to paraspinal muscle measurements, subcutaneous fat thickness, and BMI. Disc degeneration was classified using the Pfirrmann grading system, and statistical analysis was performed using IBM SPSS 25.0. Result: The mean age of participants was 45.6±12.3 years. Higher BMI (r=0.41) and increased subcutaneous fat thickness (r=0.46) showed a significant positive correlation with LDH severity (p<0.001). Conversely, paraspinal muscle cross-sectional area (CSA) was negatively correlated with LDH severity (r=0.49, p<0.001). Multivariate regression analysis revealed that age, sex, BMI, subcutaneous fat thickness, and paraspinal muscle CSA were statistically significantly associated with LDH (p<0.01). Subgroup analysis by sex demonstrated similar correlations between paraspinal muscle size, subcutaneous fat thickness, and LDH severity in both male and female groups. Conclusion Lumbar disc herniation severity is associated with increased BMI and subcutaneous fat thickness, as well as decreased paraspinal muscle mass. Normalized muscle parameters reduce sex-related discrepancies and establish an effective MRI-based risk assessment approach.

Relationship of oocyte diameter and risk factors, embryo development during IVF treatment Introduction: We aimed to determine whether the simple non-invasive measurement of oocyte size using a time-lapse system and assess the impact on occurrence of fertilization and embryo quality in assisted reproduction cycles. Materials and methods: A retrospective study was performed on 70 infertile patients who underwent the first IVF cycle at Mon-CL hospital. A total of 70 cycles which yielded 483 metaphase II oocytes were included in the analysis. In addition, we evaluated age, body mass index, ovarian reserve markers, fertilization and good embryo rate. The results were processed using SPSS 21.0. Results: The patients’s age ranged from 22 to 45 years (34.94±4.89 on average). The mean oocyte cytoplasmic diameter was 115.35±5.19 µm, total diameter was 167.61±9.61 µm, zona pellucida thickness was 21.58±4.09. There was no statistically significant association between oocyte size and the occurrence of fertilization or the qualitative embryo classification on day 3. Age, body mass index, cause of infertility, and ovarian response did not affect oocyte sizes.

Background: Tick-borne encephalitis is human viral infection involving the nervous system and transmitted by the bite of infected tick. The TBE Virus is distributed in different geographical areas by three widespread subtypes of the virus: The Far East, Europe, and Siberia. The Far East type has a mortality rate was 30-35%, the European type has a mortality rate of 2.2%, and the Siberian type has a mortality rate of 6-8% (A.G. Pletnev, 1998) [2].
In recent years, human cases of tick-borne infections have been reported in 19 European countries and four Asian countries (Mongolia, China, Japan, and South Korea) [3].
Human cases of tick-borne encephalitis, tick-borne rickettsiosis, and tick-borne borreliosis have been registered in Mongolia since 2005. Deaths have been reported year by year [5].
During 2005 to 2021, tick-borne rickettsiosis (71.6%), tick-borne encephalitis (17.3%) and tick-borne borreliosis (52.9%) were confirmed by epidemiological, clinical and laboratory tests at the NCZD.
Tick-borne encephalitis was registered in 63 soums of 15 provinces and 9 districts of the capital city, of which 90% were infected with tick bites in Selenge and Bulgan provinces. The average mortality rate is 4.9% (14), of which 28.6% in Bulgan province and 2.7% in Selenge province.
Tick-borne encephalitis is the leading cause of death in Bugat soum of Bulgan province and more infected men about 40 years of age [7]. Purpose : Collect ticks from selected soums of the provinces, identify tick species, species composition, distribution, tick densities, pathogens of tick-borne diseases, conduct population surveys to assess the risk of tick-borne infections, and identify tick-borne infections. Material and Method: Ticks were collected by flag from birch trees in birch forests and meadows with biotope and overgrown berries, determined morphological analyze and molecular biological investigation for detecting tickborne pathogens.
Questionnaires were collected from selected soum residents according to a specially designed randomized epidemiological and clinical survey card, collected information and forms were submitted to soum hospitals with a history of tick bites (according to clinical criteria). Serological tests were performed to detect IgG-specific antibodies to the collected serum mites. Result and conclusion Collected 121 ticks (120 I. persulcatus and 1 D. nuttalli) and not wound egg, larvae, nymphs. By molecular biological investigation detected 3.5% of I.persulcatus from Khutag-Undur soum of Bulgan province, 3.5% of anaplasmosis, and 14.1% of I.persulcatus mites from Bugat soum. 1.5% borreliosis, 3.1% anaplasmosis.
Detected DNA of 100% tick-borne rickettsiosis from D.nutalli ticks and determined circulation of infection among tick in Bugat and Khutag-Undur soums of Bulgan province.
247 people were surveyed, 56 blood serum from cases. Detected Q fever, erysipelas, and anaplasmosis, tick-borne borreliosis 3 (5.4%), tick-borne rickettsiosis 26 (46.4%), Japanese encephalitis 3 (5.4%), tick-borne encephalitis tick-borne rickettsiosis 6 (13.0%), tick-borne rickettsiosis tick-borne borreliosis 1 (1.8%), tick’s rickettsiosis Japanese encephalitis 1 (1.8%), tick-borne encephalitis tick-borne borreliosis 1 (1.8%).
By investigation, vaccination (88%) and wearing long-sleeved shirts and pants (81%) were the most effective ways to prevent tick bites (81%) [15]. According to our research, the percent of population knowledge in Bulgan province was insufficient (40.9%) which there is a lack of information, training and advertisement among the population in the province.

Introduction: PCOS prevalence is 5-10 percent among reproductive age women in worldwide. It is caused by imbalance of sex hormones which ultimately leads to menstrual irregularities, infertility, anovulation and other metabolic disturbances. Most women with chronic anovulation is caused by polycystic ovary syndrome [PCOS] The Rotterdam criteria is useful diagnostic tool for PCOS. In Mongolia there is almost no study on PCOS related infertility and there are increasing trend infertility among reproductive aged women with PCOS, lead us to conduct the study. Objective: The aim of this study was to estimate incidence of PCOS and to study clinical and biochemical characteristics of PCOS among infertility women. Material and Methods: We used the cross-sectional and case control study designs. Total 1334 infertility women enrolled in this study. The study was conducted after approval from the Ethical and research review board of the hospital, and written informed consent was taken from all the women. Among 114 women with PCOS were found by Rotterdam’s criteria at the Infertility and reproductive department, National Center for Maternal and Child Health, between December, 2018 - 2019. Total of 43 females with PCOS were screened among 1334 infertile women. All parameters were assessed either with ELISA in 43 infertile PCOS women and 17 age matched apparently healthy controls diagnosed according to Rotterdam consensus. IDF diagnostic criteria for MS was used. The PCOS patients divided into following groups: (1) with MS ( n=42) and (2) without MS (n=72). Results: The main age, body mass index (BMI), and duration of infertility were 28.7±4.1 years, 27.3±5.2 kg/ m² and 4.4±3.1y, respectively. Among patients 57.9% of them have oligomenorrhea, 22.8% with amenorrhea, primary infertility 57.0% and 51.9% with hirsutism and acne 50.8%. As a result of hormone assays were LH 9.3±3.5mIU/ml, LH/FSH 1.6 ±0.83 [0.1-3.6], AMH 6.1ng/ml ±3.6 /2.9-21.0/. The prevalence of MS was 36.8%. The variables including age (30.9±4.9), body mass (75.9±11.6kg) and also some metabolic parameters which is hypertension (133.6/88.4±13.6 mm Hg), WC (94.1±8.6 cm) and high triglyceride (1.8±1.0 mmol/l) were observed in MS group compared to without MS group. Conclusion Among 1334 women with infertility, the incidence of PCOS 8.7% (116), close to the prevalence in other countries. Considering the diagnose was confirmed of three criteria by the Rotterdam criteria. We found out that the prevalence of metabolic syndrome was 35.3% among infertility women with PCOS. Age, BMI, WC, amenorrhea, acne and acanthosis nigricans, were highly related to metabolic syndrome.

BACKGROUND. In the world, infertility occurs in 10-15% of the total couples and male infertility accounts for 40-50% of the infertile cases. Infertility frequency in Mongolia is 8.7% in 2003 and 11.6% in 2013. According to the Child and Maternity hospital study, 25.6% of infertility is due to men. Microdeletions of the Y chromosome long arm are the most common molecular genetic causes of severe infertility in men. They affect three regions including azoospermia factors (AZFa, AZFb and AZFc), which contain various genes involved in spermatogenesis. OBJECTIVES. The aim of the present study is to investigate the relationship between sexual hormones and AZF microdeletion on Y chromosome in Mongolian infertile men with azoospermia and severe oligozoospermia. MATERIAL AND METHODS. Through a cross sectional study, 50 infertile men were examined for Y chromosome microdeletions from January 2018 to August 2018. We determined hormone level, testis biopsy and microdeletions of the Y chromosome using six loci of 3 regions of the AZF gene were investigated by multiplex polymerase chain reaction. Semen analysis was performed on samples obtained by self-masturbation at the hospital after 2-7 days of sexual abstinence. Reproductive hormone level in serum including total testosterone, follicular stimulating hormone (FSH), and LH is measured at time 8 am to 11 am. If sperm is not recovered, testicular biopsy was performed on the patient. All collected datas were evaluated with Statistical Package for Social Sciences (SPSS, version 22.0). RESULTS. The rate of microdeletion was 4.0% (2 out of 50 patients). The deletion was on AZFa in the first patient, AZFc in the second patient. The patients with Y chromosome microdeletion had azoospermia. AZFa deleted patient has sertoli cell only syndrome in testis biopsy with FSH 58.0 mIU/ml, LH 12.0 mIU/ml, total testosterone 5.0 ng/ml. AZFc deleted patient had FSH 23.85 mIU/ml, LH 13.01 mIU/ml, total testosterone 4.06 ng/ml. Serum FSH and LH levels were significantly higher in Y chromosome deleted group and FSH level was significantly lower in sperm-retrieved group on TESE. СONCLUSION. We determined 2 cases of Y chromosome microdeletion (4.0%) in infertile men. Serum FSH and LH levels were significantly higher in Y chromosome deleted group.

BACKGROUND: Infertility rate among Mongolian couples was about 8.7% in 2003. According to researchers in Mongolia, the causes of infertility in male is about 25.6%, in female is about 45.8%, in both couples is 18.8% and unexplained infertility is about 9.8%. Women’s previous disease such as abdominal inflammatory diseases, disorders of pregnancy and surgical diseases of reproductive system can lead to infertility. Infertility has been setting 5th rank on list of human disability as shown as problem about quality of human life. METHODS: We surveyd about secondary infertile women, who has approved by inclusion criteria and determined infertility risks. We designed case-control study. We collected 52 data at “Post partum department” of “First Maternity Hospital” for control group, and 22 data at “Women stationary” of “First Maternity Hospital” for case group (ratio 2:1). Data analyzed by STATA for OR (logistic regression tests) and Microsoft Excel. RESULT: The most common previous disease is pelvic inflammatory disease (OR=2.2) р<0.001 before infertility situation. There was statistical reliability diseases. Including: female reproductive system surgery (OR=2.1), pelvic surgical diseases (OR=1.9) and complication of previous pregnancy (1.2). CONCLUSION: Pelvic inflammatory disease, surgical diseases of female reproductive system, complication of previous pregnancy and pelvic surgical diseases are the risk factors of female secondary infertility.

BackgroundPolycystic ovary syndrome (PCOS) is one of the most common female endocrine disorders affecting women of reproductive age, with a prevalence of about 5%–10% in the general population. PCOS is characterized by menstrual disturbances due to hirsutism, chronic anovulation or oligoovulation, and acne due to excessive androgen production (hyperandrogenemia). The pathogenesis of PCOS is still unexplained. Following the main criteria of diagnosis (Rotterdam Consensus 2003), Dewailly, Welt and Pehlivanov divided the patients with PCOS into 4 phenotype groups: Oligo + HA + PCO, Oligo + HA, HA + PCO, Oligo + PCO. ObjectiveThis aim of the study was to compare gonadotropin levels in serum of reproduction age for comparative healthy women and polycystic ovary syndrome (PCOS).MethodsA cross-sectional study was performed comprising 425 comparative healthy women of reproductive age group 18-35 (<20 n=76, 21-25 n=131, 26-30 n=92, 31-35 n=126). To collect blood sample 4 times of healthy, normal menstrual cycle and body mass index (BMI) of women. To determine FSH, LH hormone in serum by ELISA (Eucardio lab kit used). To evaluate FSH, LH, LH/FSH normal menstrual phase (early follicular phase,late follicular phase, ovulation and mid-luteal phase). PCOS patients divided 2 type (oligo+ha, ha+pco).ResultsThe mean age was group A 26.33±5.28, group B 24.9±4.93, and group C 29.75±4.12, BMI a; 22.35±2.95, b; 28.88±3.85, c; 28.0±3.19. The mean level was FSH a; 4.64±1.65 mIU/ml, b; 12.07±3.85 mIU/ml, c; 5.35±7.20 mIU/ml, LH a; 6.42±3.3 mIU/ml, b; 39.43±15.89 mIU/ml, c; 10.89±2.53 mIU/ml of PCOS. To correlate FSH, LH, LH/FSH level was women was significantly (p<0.05).Conclusion: The increased level of LH, LH/FSH strongly correlates with the clinical degree of amenorrhea and hyperandrogenism.It seems that LH, LH/FSH could be a crucial diagnostic and predictive factor among women with menstrual disorders or presence of polycystic ovaries.