1. Full name: Nguyen Thi Hien                                        2. Sex: Female

3. Date of birth: May 13th, 1981                                     4. Place of birth: Bac Giang

5. Admission decision number: No 5598/QĐ-ĐHKHTN, dated on November 31st, 2015 by Rector of VNU University of Science.

6. Changes in academic process:

Extension decision number 4735 /QĐ-ĐHKHTN, dated on December 28th, 2018 by Rector of VNU University of Science.

7. Official thesis title: Research the effects of benzene, toluene, ethylbenzene and xylene groups on the expression of CYP2E1 gene Paint workers occupationally exposed.

8. Major: Biochemistry

9. Code: 9420101.16

10. Supervisors:

            Assoc.Prof.Dr. Bui Phuong Thuan

            Assoc.Prof.Dr. Nguyen Quang Huy

11. Summary of the new findings of the thesis

Successfully determining the adsorbent levels of BTEX in workers with occupational exposure.

There were 82.19% of the studied subjects having the BTEX exposed concentration limit higher than allowed values, and 65.75% of the studied subjects having the biological indices of BTEX absorbent exceeds the allowed limit.

Results showed that the current situation of the BTEX exposure does not conrrespond the allowed limits on the biological indices are using in Vietnam

Successfully determining the expression of CYP2E1 gene in workers with occupational exposure.

The mRNA expression level of CYP2E1 in BTEX exposed group was significantly higher (approximate 10.47 times) than that in non-exposed group. Moreover, the age and the exposure duration did not affect the expression level of CYP2E1.

Logistic regression model showed that BTEX is the factor affecting the mRNA expression level of CYP2E1 (OR = 6.2; 95% CI: 1.10 - 34.87; p <0.05).

The BTEX exposed concentration limit was strongly correlated with the mRNA expression level of CYP2E1 (correlation coefficient R = 0.87). Thus, the mRNA expression level of CYP2E1 is proposed as the biomarker for BTEX exposed workers.

4 single nucleotide polymorphisms (SNPs) were determined in the promoter of CYP2E1 by sequencing. Although 4 SPNs of CYP2E1 did not affect the expression level of CYP2E1 mRNA, the relationship between these polymorphims and anemia diseases is shown. The subjects with allele variants were at risks of anemia higher than subjects without allele variants from 10.45 to 12.8 times, the difference was statistically significant. All of subjects containing two variant alleles are anemic.

12. Practical applicability, if any:

The thesis has found that the effect of BTEX group increases the mRNA expression of CYP2E1 gene, the level of mRNA expression of CYP2E1 gene is closely correlated with the total exposure value of the BTEX group. The research results of the thesis serve as a scientific basis for the proposal of using the mRNA index of CYP2E1 gene as a biological exposure index for workers who have simultaneous exposure to BTEX

13. Further research directions, if any:

- Continuing research to propose the use of mRNA of CYP2E1 gene as a biological exposure index for workers exposed to BTEX group.

- Continuing research with a larger number of samples to determine the role of polymorphisms on metabolism and excretion of BTEX, as well as the influence of BTEX on the genotypes of each polymorph. From there, it serves as a basis for the recommendation and arrangement of jobs suitable for those who carry genotypes at risk of intoxication with BTEX, prevention of occupational diseases.

14. Thesis-related publications:

1. Nguyen Thi Hien, Nguyen Quang Huy, Nguyen Thi Thanh Huyen (2017), “Assessment of Benzene and Toluene Exposure of Workers from some Paint and Shoe Companies”, VNU Journal of Science: Natural Sciences and Technology, vol.33(1S), pp. 200-206.

2. Nguyen Thi Hien, Do Thi Cam Nhung, Nguyen Phu Hung, Nguyen Thi Hong Van, Bui Phuong Thuan, Nguyen Quang Huy (2018), “Genetic Polymorphism in Promoter Sequence of CYP2E1 Gene in Paint Manufacturing Workers Exposed to Volatile Organic Compounds”, VNU Journal of Science: Natural Sciences and Technology, Vol..34(4), tr. 89-96.

3. Nguyen Thi Hien, Do Thi Cam Nhung, Nguyen Phu Hung, Bui Phuong Thuan, Nguyen Quang Huy (2019), “The relationship between mRNA expression of CYP2E1 gene and the exposure limits of benzene, toluene, xylene and ethylbenzen in paint workers”, Safety  - Health  & Working Environment, (1,2&3), pp 17-23. 

4. Nguyen Thi Hien, Do Thi Cam Nhung, Nguyen Phu Hung, Nguyen Thi Hong Van, Bui Phuong Thuan, Nguyen Quang Huy (2019), “Expression of CYP2E1 Gene in Paint Workers Occupationally Exposed to Organic Solvents”, VNU Journal of Science, Natural Sciences and Technology, Vol. 35, No. 3 pp 71-79