Modeling and Predicting Pulmonary Tuberculosis Incidence and Its Association with Air Pollution and Meteorological Factors Using an ARIMAX Model: An Ecological Study in Ningbo of China.

The autoregressive integrated moving average with exogenous regressors (ARIMAX) modeling studies of pulmonary tuberculosis (PTB) are still rare. This study aims to explore whether incorporating air pollution and meteorological factors can improve the performance of a time series model in predicting PTB. We collected the monthly incidence of PTB, records of six air pollutants and six meteorological factors in Ningbo of China from January 2015 to December 2019. Then, we constructed the ARIMA, univariate ARIMAX, and multivariate ARIMAX models. The ARIMAX model incorporated ambient factors, while the ARIMA model did not. After prewhitening, the cross-correlation analysis showed that PTB incidence was related to air pollution and meteorological factors with a lag effect. Air pollution and meteorological factors also had a correlation. We found that the multivariate ARIMAX model incorporating both the ozone with 0-month lag and the atmospheric pressure with 11-month lag had the best performance for predicting the incidence of PTB in 2019, with the lowest fitted mean absolute percentage error (MAPE) of 2.9097% and test MAPE of 9.2643%. However, ARIMAX has limited improvement in prediction accuracy compared with the ARIMA model. Our study also suggests the role of protecting the environment and reducing pollutants in controlling PTB and other infectious diseases.

[Detecting DNA damage of human lymphocytes exposed to 1,2-DCE with γH2AX identified antibody using flow cytometer assay].

OBJECTIVE: To study DNA damage of human peripheral blood lymphocytes exposed to 1,2-dichloroethane (1,2-DCE) with flow cytometry (FCM) assay. METHODS: The lymphocytes were obtained from 21 workers who are occupationally exposed to 1,2-DCE (exposed group) and 27 workers who were not exposed to 1,2-DCE in the same factory (inner control) and 28 island residents who had never been occupationally exposed to adverse factors (external control). FCM assay was adopted to detect DNA damage of the lymphocytes of each group. Lymphocytes of the health people were incubated with 1,2-DCE at different doses, and FCM assay was used to detect DNA damage. RESULTS: DNA damage rate (%) of the exposed group of exposed workers (4.05% ± 2.55%) was significantly higher than the inner control group of workers (1.97% ± 1.40%) and external control groups of island residents (0.23% ± 0.13%), and the DNA damage of inner control was higher than the external control, all the differences were statistically significant (P < 0.01 or P < 0.05). The geometric mean fluorescence intensity of the workers in the exposed group (3.33 ± 3.01) was significantly higher than the (2.07 ± 0.58) only (P < 0.05). There was no significant difference in the DNA damage rate as well as the geometric mean fluorescence intensity among the exposed group of workers with different years of working period (P > 0.05). In vitro, the fluorescence intensity at the dose of 20, 30 µmol/L for 0.5 h exposure showed statistical significance compared with the negative control group (P < 0.01). The DNA damage rate at the dose of 20, 30 µmol/L for 1.0 h exposure was statistically significant compared with the negative control group (P < 0.05, P < 0.01); The fluorescence intensity at the dose of 10, 20, 30 µmol/L for 1.0 h exposure was statistically significant compared with the negative control group (P < 0.05, P < 0.01). CONCLUSION: 1,2-DEC can cause DNA damage. And γH2AX FCM assay can be a sensitive, objective and effective method of detecting DNA damage of peripheral blood lymphocytes.

[Detection of DNA damage of workers occupationally exposed to lead with flow cytometer assay].

OBJECTIVE: To study DNA damage of workers occupationally exposed to lead with flow cytometer assay. METHODS: The lymphocytes were obtained from 41 workers occupationally exposed to lead (comparable group) and another 50 from control group. Flow cytometer (FCM) assay was used to detect DNA damage. RESULTS: DNA damage rate and geometric mean fluorescence intensity in the comparable group were significantly higher than those in the control group (P<0.05). There were no significant differences in the DNA damage and geometric mean fluorescence intensity between different age groups (P>0.05). The differences in correlation analysis between blood lead, urine lead, delta-ALA and DNA damage rate were not significant (P>0.05). The correlation analysis showed no statistical significance between concentration of blood lead, urine lead, delta-ALA and geometric mean fluorescence intensity (P>0.05). There was positive correlations not only between the high concentration of blood lead, delta-ALA and damage rate of DNA, but also between the high concentration of blood lead and geometric mean fluorescence intensity. The coefficient r showed statistical significance (P<0.05). CONCLUSION: Occupational lead exposure can cause DNA damage. Gamma H2AX flow cytometer assay is a sensitive, objective and effective method for detection of DNA damage of peripheral blood lymphocytes.

[DMF-induced adult hepatocyte apoptosis and its effects on expression of Bcl-2, Bax and Caspase-3].

OBJECTIVE: To investigate the apoptosis-inducing effect of DMF on the human liver cells (HL-7702) in vitro. METHODS: Liver cells were exposed to different concentrations of DMF (0, 50, 100, 150, 200 mmol/L) for 12 hours. Apoptotic rate, the expression of Bax, Bcl-2 and Caspase-3 in liver cells were measured by FCM and western blotting respectively. RESULTS: The increase in apoptotic rate of hepatocytes in concentration-manner was shown after DMF treatment for 12 h. After treatment the expression of Bcl-2 was decreased steadily and lower than the control group (P < 0.01), the expression of Bax showed no significant difference among the groups of different dosage by one-factor analysis of variance (P > 0.05), as the increase of the dosage of DMF. The ratio of Bcl-2/Bax dropped with the dosage of DMF increasing, and the ratio in 200 mmol/L of DMF was significantly lower than that of the control (P < 0.01). The new lands of procaspase-3 in 150, 200 mmol/L were observed, which demonstrated that there was active caspase-3. CONCLUSION: DMF can induce apoptosis of cultured adult normal hepatocytes in vitro, and the mechanism might be related to the decrease of Bcl-2/Bax and the cleavage of Caspase-3.