Даваа–Баасан 08:30–20:00 · Бямба 09:00–16:00
library@mnums.edu.mn
/

Oyuntsetseg, Khasag

Loading...
Thumbnail Image
Товч нэр
Oyuntsetseg, Khasag
Бүтэн нэр
Oyuntsetseg Khasag
Латин нэр
Oyuntsetseg Khasag
Албан тушаал
Судлаач
Харьяалал
ORCID

Settings

Now showing 1 - 6 of 6
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    IDDF2023-ABS-0237 Characteristics of helicobacter pylori from mongolia where burdening high incidence of gastric cancer
    (2023-06-01)
    Boldbaatar Gantuya
    ;
    Batsaikhan Saruuljavkhlan
    ;
    Khasag Oyuntsetseg
    ;
    Yoshio Yamaoka
    ;
    Vo Phuoc Tuan
    Background Globally Mongolia is the top country in the incidence of gastric cancer followed by Japan and Korea which are East Asian countries. Helicobacter pylori (H. pylori) infection possessing East-Asian-type CagA is more associated with gastric carcinogenesis than Western-type CagA. The prevalence of H. pylori is around 70% in Mongolia; however, the previous study reported Mongolians infected with H. pylori possessing Western-type CagA. Therefore, we aimed to characterize Mongolian H. pylori infection based on a whole genome sequencing method. Methods Totally 130 strains are sequenced from Mongolian H. pylori isolates (20 gastric cancer and 110 non-cancer cases) and 401 data from 38 countries H. pylori whole genome data were extracted for the FineStructure analysis. The complete CagA gene and 7 housekeeping genes were extracted for constructing a phylogenetic tree. Results Based on whole genomic FineStructure analysis we found new H. pylori population named as HpMongolia among Mongolian gastric cancer and non-gastric cancer cases which are separately clustered among published global H. pylori populations (IDDF2023-ABS-0237-Figure 1. FineStructure analysis for H.pylori population). Complete CagA gene sequencing data showed that HpMongolia possessed with J-Western type cagA and it was the highest distribution of J-Western cagA positive H. pylori strains identified in Mongolia (67.7%) followed by Canada, North America (10%), and Okinawa, Japan (5.9%) among the published population (IDDF2023-ABS-0237-Figure 2. Global H.pylori phylogenetic tree based on 7-housekeeping genes). The phylogenetic tree constructed based on 7 housekeeping genes result showed the closest H. pylori population with HpMongolia is the HpAmerind which is isolated from native American people (IDDF2023-ABS-0237-Figure 3. H.pylori CagA genotyping map). Conclusions Mongolians provide new H. pylori population is named as HpMongolia which contains most of the cases Japanese-Western type cagA both for cancer and non-cancer cases. Therefore Japanese-Western type cagA might have advantageous for human migration study markers and further clinical implications.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    IDDF2023-ABS-0226 Initial results of screening program in mongolia where burdening high gastric cancer
    (2023-06-01)
    Gantuya Boldbaatar
    ;
    Khasag Oyuntsetseg
    ;
    Sarantuya Tserenchimed
    ;
    Tsevelnorov Khurelbaatar
    ;
    Bilguun Jargalsaikhan
    Background Mongolia is the leading country in the incidence and mortality rate of gastric cancer. According to the national data, TNM stage at the time of cancer diagnosis, a gastric cancer diagnosis is 0.4% in the carcinoma-in-situ stage, 5.1% in stage I, 15.2% in stage II, 42.7% in stage III and 36.5% in stage IV 36.5% were diagnosed respectively. Whereas almost 80% of people are diagnosed with early-stage of gastric cancer in Japan and Korea, where national cancer screening programs have been initiated for several decades. In 2022 national cancer screening program for upper gastrointestinal neoplasia was initiated; therefore, we aimed to conduct a multi-center study to determine gastric cancer incidence among the Mongolian population. Methods The cross-sectional study was performed to examine the detection rate of gastric cancer cases based on a national screening program from May to December 2022. The primary outcomes of this study were to define the detection rate (proportion of positive cases among individuals who underwent endoscopic screening) and to determine the characteristics of the cancer type, including its precursor disease based on histological examination. Results During the screening program, a total of 34581 participants’ data were collected from 28 endoscopy centers from Ulaanbaatar city and the western eastern, southern, and northern parts of the Mongolian province’s hospitals. The age range of the study participants was 35 to 93 years old. In terms of gender, 56.8% are men and 43.13% are women. The mean with SD age of people diagnosed with gastric cancer was 61.56±1.11, while the mean with SD age of healthy people was 53.84 ± 0.29 (p-value 0.0001). Among them, 113 (0.1%) patients were diagnosed with gastric cancer. The proportion of early-stage gastric cancer cases was 34 (30%) based on endoscopic and histological evaluation. The overall cases included in the national screening program are summarized in Figure 1 (IDDF2023-ABS-0226 Figure 1. Initial result from the national screening program for gastric cancer). Conclusions The initiation of the Mongolian national gastric cancer screening program could increase to detect the proportion of gastric cancer in its early stage. Therefore, screening programs should be continuous further. However, the quality of endoscopic examination should be improved.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    IDDF2022-ABS-0128 A novel pathogen enterococcus hirae induced dysbiosis in the stomach and the genomic instability to promote gastric cancer
    (2022-09-01)
    Batsaikhan Saruuljavkhlan
    ;
    Boldbaatar Gantuya
    ;
    Junko K. Akada
    ;
    Takashi Matsumoto
    ;
    Ricky Indra Alfaray
    Background Previous our microbiome analysis indicates that Enterococcus sp. predominance of microbial composition has been determined in patients with gastric cancer (GC) by 16S rRNA metagenomic analysis. We aimed to determine whether this bacterium could promote the emergence and progression of GC. Methods The effects of E. hirae and Helicobacter pylori (clinical strain Mon-Ke2 as control) were assessed in a gastric epithelial cell line (AGS cells). The cell toxicity of AGS cells is identified by lactate dehydrogenase levels. The DNA double-strand breaks (DSBs) were assessed by gamma-H2AX expressions using immunoblotting; and single-cell gel electrophoresis (SCGE). AGS cells were analyzed for the rapid oxygen species (ROS) expressions response after E. hirae and H. pylori infections. Results E. hirae was successfully isolated from the gastric mucosal specimen of a GC patient for the first time. The whole-genome sequence of E. hirae was confirmed by next-generation sequencing. E. hirae-infected AGS cells showed abnormal morphological changes. Infections of E. hirae and H. pylori significantly induced cell death and expression of gH2AX in AGS cells. Besides, the expression of gH2AX and DSBs was confirmed by SCGE comet formation. Interestingly, co-infection of H. pylori and E. hirae had a synergistic effect on the severity of DSBs. E. hirae could induce intranucleus and mitochondrial ROS in AGS cells same as H. pylori. We investigated whether only live E. hirae, or its released factor(s) can cause DNA damage. Supernatant from AGS cells infected with E. hirae could induce the gH2AX, whereas H. pylori required cell adhesion to induce gH2AX. The complete genome of E. hirae totally contained 2570 genes and 10 known virulence factor genes (e.g., Enterococcus pore-forming toxin). Conclusions E. hirae-related dysbiosis in the stomach might increase the risk for GC, resulting in gained the genomic instability of gastric cells, as well as H. pylori infection. Further research investigating the impacts of this pathogen on the human host using the gastric organoid model is needed since several studies have shown that other species of Enterococcus induce cancer-promoting events resulting in DNA damage in gastric/colonic mucosa, and hepatic cells.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Western-Type Helicobacter pylori CagA are the Most Frequent Type in Mongolian Patients
    (MDPI AG, 2019-05)
    Tserentogtokh, Tegshee
    ;
    Gantuya, Boldbaatar
    ;
    Subsomwong, Phawinee
    ;
    Oyuntsetseg, Khasag
    ;
    Bolor, Dashdorj
    Helicobacter pylori infection possessing East-Asian-type CagA is associated with carcinogenesis. Mongolia has the highest mortality rate from gastric cancer. Therefore, we evaluated the CagA status in the Mongolian population. High risk and gastric cancer patients were determined using endoscopy and histological examination. H. pylori strains were isolated from different locations in Mongolia. The CagA subtypes (East-Asian-type or Western-type, based on sequencing of Glu-Pro-Ile-Tyr-Ala (EPIYA) segments) and vacA genotypes (s and m regions) were determined using PCR-based sequencing and PCR, respectively. In total, 368 patients were examined (341 gastritis, 10 peptic ulcer, and 17 gastric cancer). Sixty-two (16.8%) strains were cagA-negative and 306 (83.1%) were cagA-positive (293 Western-type, 12 East-Asian-type, and one hybrid type). All cagA-negative strains were isolated from gastritis patients. In the gastritis group, 78.6% (268/341) had Western-type CagA, 2.9% (10/341) had East-Asian-type, and 18.2% (61/341) were cagA-negative. However, all H. pylori from gastric cancer patients possessed Western-type CagA. Histological analyses showed that East-Asian-type CagA was the most virulent strains, followed by Western-type and cagA-negative strains. This finding agreed with the current consensus. CagA-positive strains were the most virulent type. However, the fact that different CagA types can explain the high incidence of gastric cancer might be inapplicable in Mongolia.
    Scopus© Citations 21
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    New observations regarding Helicobacter pylori and gastric cancer in Mongolia
    (Wiley, 2018-08)
    Gantuya, Boldbaatar
    ;
    Bolor, Dashdorj
    ;
    Oyuntsetseg, Khasag
    ;
    Erdene-Ochir, Yansan
    ;
    Sanduijav, Ruvjir
    BACKGROUND: The incidence and mortality of gastric cancer in Mongolia is among the highest in the world. METHODS: This was a case-control study in which upper gastrointestinal endoscopy, gastric histology, Helicobacter pylori testing, and risk factor questionnaires were obtained. Histologic subtypes were determined by Lauren's classification. RESULTS: We enrolled 45 gastric cancer and 108 non-gastric cancer patients. Gastric cancers were located in upper part of stomach in 53.3%, main gastric body in 37.8%, and lower part of stomach in 8.9%. The majority (60%) were diffuse type, followed by intestinal type (36.7%) and indeterminate type (3.3%). H. pylori infections were CagA positive in 100% with cancer vs 81% without cancer (P = .02). The majority of CagA was non-East Asian type (95% with cancer and 94.1% without cancer). Cancer patients had typically related with excessive use of salt, hot beverages, tobacco smoking, and low ingestion of fruits. CONCLUSION: The characteristic topography of gastric cancer in Mongolia being in the gastric corpus differed from East Asian countries and was more similar to western countries. The risk factors for gastric cancer in Mongolia were similar to other high-risk areas (ie, H. pylori infection, excessive use of salt, tobacco smoking, and low ingestion of fruits).
    Scopus© Citations 15