Animals ; Chick Embryo ; physiology ; Electrocardiography ; methods ; Heart ; embryology ; physiology ; Heart Rate ; physiology

Objective To study the DNA damage of bone marrow cells of mice after exposure to Radon.Methods Twenty-four mice were randomly divided into four groups, one control group and three experimental groups with the cumulative doses of radon at 27 WLM (low dose group), 52 WLM (middle dose group) and 105 WLM ( high dose group). DNA damage induced by radon in bone marrow of mice was detected by methods of single cell gel electrophoresis (SCGE), micronucleus(MN) and laser scanning confocal microscope (LSCM) observation. Results The DNA strand breakage, rate of MN and apoptosis increased significantly in the high dose group, but not in the middle and low dose groups. Conclusions Exposure to radon could induce DNA damage in bone marrow cells of mice at high levels.

Objective To detect the changes in protein profile of rats'lung inhaled radon using two- dimensional electrophoresis(2-DE)and MS.Methods Male Wistar rats were exposed to radon with the cumulative dose up to 100,200 and 400 working level months(WLM).The total proteins of rats'lung were extracted and isolated by 2-DE.The different protein expressions were analyzed with ImageMaster 2D Platinum software and obviously altered proteins were digested by trypsin and identified by MALDI-TOF-MS.Resuits Comparison of the 2-DE images between the control and radon-exposed groups indicated 14 up-regulated and 9 down-regulated protein spots,15 of which were identified by MALDI-TOF or MALDI-TOF/TOF MS.Conclusions The 2-DE image of radon groups'lung has changed,and the lung damage effect of radon is related to some proteins.

Objective To screen and identify the differential expression genes on peripheral blood cells of mice based on the experimental animal model of radon exposure. Methods BALB/c mice were exposed in a type HD-3 multifunctional radon-room, with the accumulative doses of radon-exposure group at 105 WLM and control group at 1 WLM. Total RNA was extracted from peripheral blood cells and the methods of SMART for dscDNA synthesis and SSH for gene screening was applied. With the construction of the cDNA library enriched with differentially expressed genes, the pMD 18-T plasmid containing LacZ operator at the multiple cloning site was used to allow a blue-white screening. The TA clones were amplified by nested PCR and the reverse Northern blot was used to identify up and down regulation of the clones. The differently expressed cDNA was then sequenced and analyzed. Results The subtracted cDNA libraries were successfully constructed. A total of 390 recombinant white colonies were randomly selected. Among the 312 cDNA monoelones selected from bath forward- and reverse-subtracted libraries,41 clones were chosen to sequence for their differential expressions based on reverse Northern blot. Among the 41 sequenced clones, 10 clones with known function/annotation and 3 new ESTs with the GenBank accession numbers were obtained. Most of the known function/annotation genes were revealed to be related with cell proliferation, metabolism, cellular apoptosis and carcinogenesis. Conclusions The animal model of radon exposure was established and the cDNA library of peripheral blood cells was suceessfully constructed. Radon exposure could up- and down-regulate a series of genes. Differentially expressed genes could be identified by using SSH technique and the results may help exploring mechanisms of random exposure.

Objective To establish a model of malignant transformation of human cells in vitro to study the lung cancer induced by radon and cigarette smoke. Methods The immortalized human bronchial epithelial cells BEAS-2B were divided into control group( C ), radon group ( Rn), cigarette smoke group (Sm) and combined group (Rn-Sm). Cells were planted onto transwell membrane one day before exposure and were directly exposed to radon and cigarette smoke pumped in a gas inhalation box. After the exposure cells were trypsinized into dishes for further growth and malignancy transformation phenotype was detected in order to compare the effects due to radon and cigarette smoke exposure. Results BEAS-2B cells showed malignantly transformed phenotype by exposure to radon and cigarette smoke. A series of sequential steps emerged among transformed cells, including altered growth kinetics, resistance to serum has changed from 0. 31 ± 0. 18 to 1.92 ± 0. 27,2. 03 ± 0. 14,2.95 ± 0. 60, and anchorage-independence growth increased from (0.01 ±0.02)% to (4.89 ±0.30)%,(8.36 ±0.50)%,(11.74 ±0.69)%.After being subculture for 20 generations, cell apoptosis of the fifth generation cells exposed to radon,cigarette smoke and both was significant decreased from ( 11.76 ± 0. 17 ) % to (4. 62 ± 0. 42 ) %、 ( 8.63 ±0. 15 )%、 (3.68 ± 0. 33 )%. Conclusions BEAS-2B cells could be malignancy transformed by radon and cigarette smokein vitro, which could be used as a cell model in lung bronchial carcinogenesis.

Objective:To investigate the daily diet and living habits of Hashimoto's thyroiditis (HT) patients, and to explore the influencing factors of HT.Methods:The patients admitted to the Thyroid Surgery Clinic of Cancer Hospital Affiliated to Harbin Medical University from March to December 2021 were selected as the investigation subjects and were divided into observation group (106 patients with HT) and control group (63 healthy people). Questionnaire was used to collect the information of daily diet and living habits of the two groups, and physical examination was used to collect the information of height and weight. The levels of serum thyroid function indicators thyroid stimulating hormone (TSH), free triiodothyronine (FT 3) and free thyroxin (FT 4) were tested by automatic chemiluminescence immunoassay, and the comparison and analysis were conducted between the two groups. Multivariate logistic regression was used to analyze the influencing factors of HT. Results:The results of univariate analysis showed that there were significant differences in sex ratio and serum TSH levels between the two groups ( P < 0.05); the proportion of people in observation group who slept for less than 6 hours per day, frequently looked at their mobile phones, ate fried food ≥1 time per week, and ate meat ≥1 kg per week was higher than that in control group; however, the proportion of people in observation group who drank tea ≥1 time per week, smoked ≥1 time per week, had a salty daily taste, ate nuts ≥1 time per week, and ate vegetables ≥1 kg per week was lower than that in control group, and the differences were statistically significant ( P < 0.05). The results of multivariate logistic regression analysis showed that female, slept duration < 6 hours/day, weekly meat consumption ≥1 kg, and elevated serum TSH levels were risk factors for the onset of HT [odds ratios ( OR) = 3.37, 4.11, 2.48, 1.14, and 95% confidence intervals ( CI): 1.08 - 10.55, 1.46 - 11.59, 1.00 - 6.51, 1.00 - 1.30]; eating ≥1 kg of vegetables per week was a protective factor for the onset of HT ( OR = 0.36, 95% CI: 0.17 - 0.79). Conclusion:Female, poor diet and lifestyle habits are risk factors for the onset of HT.

Background Excessive radon exposure is considered the second risk factor for lung cancer. Since the opening of the subway in a city of Zhejiang Province, the exposure level of radioactive gas radon in subway stations and its impact on occupational health have become one of the important issues of public concern. Objective To monitor the radon concentration of subways in a city in Zhejiang Province and explore the effect of radon exposure on chromosome aberration and micronuclei in the working population. Methods A total of 55 vehicle control rooms of 55 stations affiliated to two different subway lines in a city were measured for one year; the 110 ticket offices and 55 security checkpoints from the same 55 stations were measured from 16 March to 14 June. The radon concentrations were compared by job types, subway lines, and seasons referring to Measurement methods for determination of radon in environmental air (HJ 1212-2021). Peripheral blood lymphocyte chromosome aberration and micronucleus analyses were conducted in 165 subway workers from monitoring sites for three different job types, then the influencing factors were analyzed. The detection methods were adopted from the standards of Test and assessment of chromosomal aberrations on occupational health examinations for radiation workers (GBZ/T 248-2014) and Standard for the method of micronucleus detection in lymphocytes on occupational health examination for radiation workers and exposure dose estimation (GBZ/T 328-2023). Results The radon concentration range of the target subways in Zhejiang Province was 10-320 Bq·m⁻³, all lower than the national limit (≤400 Bq·m⁻³). The differences in radon radioactivity levels among different lines, job types, and time segments were statistically significant (P<0.05). The rates of chromosomal aberration and micronucleus formation among the 165 subjects were 0.224% and 0.024%, respectively. There were significant differences in the rates of chromosome aberration and micronuclei among different jobs (vehicle control room, ticket office, security checkpoint) (P<0.05), but the abnormal rates were lower than the limits of the corresponding national standard. No significant correlation was found between jobs and chromosomal aberrations or micronuclei (P>0.05). Chromosome aberration and micronuclei varied by age, subway station seniority, and smoking (P<0.05). No effect of the above factors on chromosome aberration and micronuclei was observed by logistic regression (P>0.05). Conclusion The radon concentration in the target subway system is at a normal level. The rates of chromosomal aberration and micronucleus formation vary by jobs, but both are lower than the corresponding national limits. Therefore, radon exposure has not yet caused outstanding health impact on the subway workers.