Introduction Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the principal enzymes involved in catabolism of ethanol in human body. Alcohol is initially metabolized by ADH to acetaldehyde, which is consequently oxidized by ALDH to acetic acid. Individuals with low activity of alcohol-metabolizing enzymes show low tolerance to alcohol and are therefore rapidly intoxicated. Two studies on polymorphism of alcohol metabolizing enzyme genes in Mongolian population have been implemented to the date, but no assessment study of the serum activity of the enzymes have been conducted. Materials and Methods Fasting morning blood samples were collected from 240 adults 25-54 years of age (124 males and 118 females) from all provinces and the capital city of Mongolia. The serum levels of ADH and ALDH were determined using an enzyme-linked immunosorbent assay. Result: The mean serum level of ADH was 17.6 ng/mL and of ALDH was 15.91 ng/mL. The mean levels of the two enzymes of the surveyed from UB city were significantly lower than of those who lived in rural areas (p=0.000 for both ADH and ALDH). When the survey participants were divided into three age groups (25-34 years, 35-44 years and 45-54 years of age) and their mean levels of ADH and ALDH were compared, no significant age-related differences were found (p>0.05).

Goal: To determine average values of serum total cholesterol, triglycerides, high density lipid cholesterol and low density lipid cholesterol of Mongolian adults, and compare the average values by age groups, gender and regions. Materials and Methods: Serum was separated from morning blood samples collected from 1737 individuals 15-64 years of age (707 males and 1030 females) from 21 aimags and Ulaanbaatar city, and stored at-30°C until analysis. Mean levels of cholesterol, triglycerides, HDL and LDL were determined using photometric system. Results: The overall mean serum level of cholesterol was 159.06 mg/dl (95% CI 155.58-162.53), of triglycerides was 121.65 mg/dl (95% CI 116.77-126.53), of HDL was 61.12 mg/dl (95% CI 59.77-62.47), and of LDL was 130.53 mg/dl (95% CI 128.26-132.80). When the survey participants were divided into five age groups (15-24, 25-34, 35-44, 45-54 and 55-64 years of age) and their mean levels of cholesterol, triglycerides, HDL and LDL were compared, no statistically significant differences were observed between age groups. When the mean levels of lipids were compared between sexes, statistically significant differences were observed for cholesterol and triglycerides, and no statistically significant differences were observed for HDl and LDL.

The serum activity levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are important biochemical indicators of changes in the liver and coronary system function. The correct determination of changes in the activity levels of the transferases is essential for differential diagnosis and appropriate treatment of the diseases. Goal: The aim of this study was to determine the mean activity levels of ALT and AST of the Mongolian population. Materials and Methods: Serum was separated from morning blood samples collected from 1732 individuals 15-64 years of age (706 males, 1026 females) from 21 aimags and Ulaanbaatar city, and stored at -30°C until analysis. Ac¬tivity levels of alanine aminotransferase and aspartate aminotransferase were determined using photometric system. Results: The overall mean serum activity level of AST was 25.52 U/L and of ALT was 21.31 U/L. No statistically sig¬nificant differences were observed between the surveyed from Ulaanbaatar and from rural area, but the mean activity level of both enzymes was statistically significantly lower in women than in men (р<0.05 for both ALT and AST). When the survey participants were divided into five age groups (15-24 years, 25-34 years, 35-44 years, 45-54 years and 55-64 years of age) and their mean activity levels of AST and ALT were compared, it was observed that the activity of both enzymes increased with age (p<0.05).

Goal: To study migration of toxic chemicals from water containters into stored waterMaterial and Methods:Experimental study was carried out in the Health Reference laboratory of Public Health Institute. In the study, as examples of water containers that are commonly used among population, the samples of water containers narrow opened container intended for keeping oil, aluminium container, large blue container (plastic), and metal container were purchased from Narantuul market and container with volume of 1 liter for potable water was purchased from supermarket and were tested. For determination of heavy metal migration, dissolving soultion or 3% In the solution of 3% chloric acid and for determination of hygiene parameters 3% acidic acid were used, respectively. In the solution of 3% chloric acid 6 heavy metals including iron (Fe), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd) and manganese (Mn) were determined by Varian 210 D AAS-10 in accordance with the method stated in the standard of GOST 5370-50. In the solution of 3% chloric acide the content of formalyne was determined by qualitative method of Shiph and quantative titration methodr, ethylen and salicilic acid by qualitative method, oxidation of organic matters by bichromate titration method and formaldehyde by iodometer method, respectively. Results of analysis were processed by Origin 7.0 software.Conclusions:1. The migration of lead from oil container and large blue plastic container as used for water storage and carriage was detected 500-800 times higher in oil container and 60-72 times higher in large blue plastic container than the acceptable maximum limit of WHO reference level and drinking water standard MNS900:2005 (0.01mg/l). 2. The migration of formaldehyde from plastic containers to food products was 1800-3900 times higher in oil container and 3600-6900 times higher in large blue container than the acceptable maximum limit of formaldehyde migration (formaldehyde 0.1 mg/l). Also 27,0-39,17 mg/l of formalin were determined in the oil container and37,67-53,43 mg/l of formalin were measured in large blue plastic container and its concentration increased over time of storage. It shows that these plastic containers can not be used for keeping drinking water and food products. 3. Lead (122-250 times higher) and cadmium (10-53 times higher) migration from aluminum container was higher than the acceptable maximum limit of national standard NMS 900-2005.4. Iron (58-90 times higher), lead (240-360 times) and cadmium (33-70 times) migration from metal container were detected higher than the acceptable maximum limit of national standard NMS 900-2005.5. The migration of formaldehyde from pure water container was 2922-28000 times higher than the acceptable maximum limit of Russian’s hygienist direction approved in 1971 (reference level is 0.1mg/l of formaldehyde).

Background: Screening programs for the detection of inherited disorders of amino acid metabolism is mandatory in most countries. Various laboratory methods are used for this purpose. We tested a high-performance liquid chromatography method for the separation of amino acids in blood and urine samples. Materials and Methods: All reagents were of the HPLC grade purity,water used for t he analysis was deionized and reagents and samples were ultrafiltrated using a micropartition system.
The analysis was performed using the HPLC system with two pumps, a C18 column and a UV detector. All evaporations were done using a vacuum concentrator.
Amino acids were derivatized using a solution of ethanol, water, triethylamine and phenyl isothiocyanate. The amino acid derivatives were separated using a linear gradient with two solvents: solvent A (sodium acetate : acetonitrile) and solvent B (water : acetonitrile).
Amino acid standards of 20, 50, 100, 200, 500, 750 and 1000 µM were prepared in 1 mM hydrochloric acid.
The EDTA blood as well as urine samples were spun at 1500 g for 15 min and then ultracentrifuged at 1500 g for 30 min. Results: Experiments with various chromatographic conditions showed that factors which influenced the amino acids separation were the type of columns, mobile phase composition, flow-rate, gradient programs and timings.
After studying the effects of changes in individual parameters of chromatographic conditions, the following method parameters were chosen: pre-column derivatization agent –PITC, separation column – C18, mobile phase –solvent A: sodium acetate : acetonitrile (98:2) and solvent B: water : acetonitrile (40:60), gradient – linear, flow-rate – 1.2 mL/min. With this method 22 amino acids were separated within 35 minutes. Conclusion The developed method is simple and can be used by medical laboratories for the detection of inborn errors of amino acid metabolism.

Introduction: Oligophrenia makes 7.3% of all mental disorders in our country. It is known that almost 4% of all diagnosed cases of oligophrenia developed as a result of an inherited disturbance of amino acid metabolism. In most countries, the frequencies of inherited diseases of amino acid metabolism in the population are determined, and preventive screening programs of newborns are implemented. No study has been conducted so far into the issue of inherited diseases of amino acid metabolism in the Mongolian population. The goal of our survey was to detect inherited disorders of amino acid metabolism in the population at risk. Materials and Methods: The collection of samples and the laboratory analysis were carried out in the following two stages:
1. The screening analysis of 514 individuals diagnosed with mental retardation was performed by paper chromatography;
2. The positivecases detected by the screening were analyzed using high-performance liquid chromatography. Results: The screening testing detected twelve potential disturbances of amino acid metabolism. Out of the twelve positive cases four individuals refused to participate in the confirmatory stage of the survey. Among the remained eight individuals, cases of hypertyrosinemia, hypervalinemia, hyperglycinemia, hyperlysinemia and pyridoxine-dependent epilepsy were detected. Conclusions
1. The fact that cases of inherited disorders of amino acid metabolism were detected among mentally retarded individuals show that the disorder is one of causes of oligophrenia.
2. A screening program of newborns should be implemented for early detection of inherited disorders of amino acid metabolism.
3. A genetic counselling and testing centre could assist in reduction of number of individuals with inherited disorders.

Background: Poor laboratory quality can lead to misdiagnosis and inappropriate treatment of patients. To demonstrate the quality and reliability of their services, medical laboratories seek accreditation to ISO 15189. We have initiated a project to assist laboratories in their efforts to obtain the accreditation. Goal: Conduct a gap analysis of the status of preparedness of medical laboratories for accreditation. Materials and Methods: Six laboratories are selected for participation in the project. In the first phase of the project, a gap analysis of the participant laboratories is conducted using an Excel program based on ISO 15189 requirements. Results: The findings reveal that the participant laboratories are the strongest in Organization and management of laboratory, Quality of examination results, Personnel and facility management and in Laboratory information management. The majority of the laboratories are hospital based, and their organization and management are well established and functional mostly due to centralized administrative guidance. The concept of quality control is effectively adapted in medical laboratories, therefore ensuring the quality of examinations and the data management are usually in line with the requirements. Weaker areas include Evaluation and audits, and Document control. Even though the laboratories do conduct evaluations and control, they do not do it regularly and, most importantly, do not keep records routinely, which cause the higher gap rate. Conclusion Policies to meet ISO 15189 requirements are in place in the participant laboratories, but their documentation and records keeping are insufficient.

Background: Iodine is a micronutrient essential for mental and physical development. One of ways to prevent from iodine deficiency is sufficient intake of iodine with food. The WHO approved method for assessment of the population’s iodine status is measurement of the concentration of iodine in urine. Goal: The goal of the survey was to assess the iodine status in 6-11 years old children and pregnant women. Materials and Method: 1697 children of 6-11 years of age and 900 pregnant women were selected from 21 aimags and Ulaanbaatar city. Concentrations of iodine in their urine were determined using the Sandell-Kolthoff reaction method. Results: The median amount of urinary iodine in 6-11-year-old children was 143.45 µg/L which was within the WHO recommended range (100.0-199.9 µg/L). 31.82% of the surveyed children had their urinary iodine less than 100 µg/L which indicated a risk of iodine deficiency. The highest frequency of children with urinary iodine less than 100 µg/L was observed in western regions (53.9%) and the lowest percentage was observed in eastern regions (17.8%).
The median concentration of urinary iodine in pregnant women was 111.35 100 µg/L which was lower than the WHO recommended value (≥150 µg/L). The median amount of urinary iodine was 127.81 µg/L for the women in Ulaanbaatar city and for those in rural areas was 108 µg/L. The overall percentage of the women with low urinary iodine was 64.1%. Conclusions
1. The median urinary iodine concentration in 6-11 years old children is within the WHO recommended range, whereas the median concentration in pregnant women is lower than the WHO recommended value.
2. 31.8% of the surveyed children and 64.1% of the pregnant women are at risk of iodine deficiency.
3. The frequency of iodine deficiency is highest in western region and is lowest in eastern and central regions.

Background: Vitamins are nutrients essential for human health. They act as coenzymes that help trigger important chemical reactions necessary for energy production. Reference values for vitamins help physicians evaluate the health status of patients and make clinical decisions. The aim of this study was to determine the mean values and reference intervals for some water-soluble vitamins of Mongolian adults. Materials and Methods: Three hundred and forty healthy adults (170 males and 170 females) of 17 to 69 years of age were selected for the study based on CLSI C28-P3 criteria Defining, establishing & Verifying reference interval in the clinical laboratory; Proposed Guidelines. The study was approved by the Resolution No.76 of 2018 of the Medical Ethics Review Committee of the Ministry of Health. Informed consents were taken from the selected individuals. Morning blood samples of the participants were collected under aseptic conditions. Levels of vitamins B₆, B₉, B₁₂ and vitamin C were measured using a high performance liquid chromatography method. The lower- and upper reference limits were defined as the 2.5th and 97.5th percentiles, respectively. The data were analyzed using SPSS and Excel programs. Results: The mean blood level of vitamin C was 11.88 mg/L (95% CI 10.47-13.29) for men and 9.62 mg/L (95% CI 8.11-11.13) for women. The calculated reference interval for males was 1.40-19.40 mg/L and 1.17-18.04 mg/L for females. The mean concentration of vitamin B₁₂ in the blood of males was 938.45 ng/L (95% CI 747.22-1129.68) and that of females was 864.03 ng/L (95% CI 603.81-1124.25). The reference interval for vitamin B₁₂ was 233.03-1597.00 ng/L in men and 132.45-1623.86 ng/L in women. The mean level of vitamin B₉ was 8.47 ng/mL (95% CI 5.64-11.30) for men and 6.91 ng/mL (95% CI 4.89-8.93) for women. The calculated reference interval for this vitamin in males was 1.04-24.74 ng/mL and that in females was 1.04-21.46 ng/mL. As for vitamin B₆, the mean concentration for men was 44.42 ng/mL (95% CI 37.01-51.83) and for women was 34.67 ng/mL (95% CI 29.97-39.39) with the reference intervals of 5.90-79.02 ng/mL for men and 5.27-61.72 ng/mL for women. Conclusion The reference values for vitamins B₆, B₉, B₁₂ and vitamin C of Mongolian adults do not differ significantly from those observed in other populations. The calculated reference intervals can be used in the practice of health laboratories.

Background: Minerals are important for the proper body functioning. They also play a role in preventing and fighting diseases. Reference values for minerals help physicians evaluate the mineral status of patients and make clinical decisions. The aim of this study was to determine the mean values and reference intervals for some minerals to be used for evaluation of the nutrition status of Mongolians. Materials and Methods: Two hundred and forty healthy adults (120 males and 120 females) of 17 to 70 years of age were selected for the study based on CLSI C28-P3 criteria Defining, establishing & Verifying reference interval in the clinical laboratory; Proposed Guidelines. The study was approved by the ethical committee of the Ministry of Health of Mongolia. Informed consents were taken from the selected individuals. Morning blood samples of the participants were collected under aseptic conditions. Levels of iron (Fe), zinc (Zn) and copper (Cu) were measured by graphite furnace atomic absorption spectrometry. The lower and upper reference limits were defined as the 2.5th and 97.5th percentiles, respectively. The data were analyzed using SPSS and Excel programs. Results: The mean level of blood iron was 30.50 µmol/L (95% CI 29.71-31.29) for men and 30.91 µmol/L (95% CI 30.03-31.79) for women. The calculated reference interval for males was 21.39-37.72 µmol/L and 19.87-39.67 µmol/L for females. The mean concentration of zinc in the blood of males was 11.00 µmol/L (95% CI 10.69-11.31) and that of females was 11.79 µmol/L (95% CI 11.39-12.19). The reference interval for blood zinc was 8.20-14.92 µmol/L in men and 8.52-16.67 µmol/L in women. The mean level of blood copper was 15.28 µmol/L (95% CI 14.64-15.89) for men and 18.08 µmol/L (95% CI 17.30-18.86) for women. The calculated reference interval for copper in males was 9.72-22.34 µmol/L and that in females was 11.18-27.27 µmol/L. Conclusion The reference values for zinc, copper and iron of Mongolian adults do not differ significantly from those observed in other countries. The calculated reference intervals can be used for evaluation of the nutrition status and making clinical decisions.