Objective To test the toxicity of genetically engineered strain R32 released to the environment.Methods Acute,chronic and cumulative toxicity test on mice,micronucleus assay of mice bone marrow cell and mice sperm malformation test were conducted to assess the toxicity of strain R32.Results R32 did not cause acute,chronic,cumulative and genetical toxic effect on mice before it absorbed heavy metal chromium.Although the mice bone marrow micronucleus frequency increased and some cumulative toxic effect emerged after R32 absorbed chromium,it did not cause acute and chronic toxicity effect on mice and mice sperm malformation rate did not increase neither.Furthermore,whether R32 absorbed heavy metal chromium or not,the effect of its secretion was not significant in all experiments compared with the control.Conclusion R32 can not cause toxic effect on mice before it absorbed chromium.Whether R32 absorbed chromium or not,the effect of its secretion was not significant in all toxicological experiments conducted in the present paper.Large content of R32 may cause some cumulative toxic effect in mice after it absorbed chromium.

Objective: To preliminarily evaluate the clinical efficacy of endoscopic argon plasma coagulation (APC) combined with sub-mucosal injection of norepinephrine saline in the treatment of radiation proctitis (RP), especially for refractory RP. Methods: Clinical data of 22 RP patients were retrospectively analyzed. The severity of RP was evaluated by a modified endoscopy scoring system (A) or Sherman′s classification (B). The criteria of successful treatment are the improvement of clinical symptoms or the cessation of bleeding (or only occasional traces of blood on the stools that do not need further treatment). Results: All 22 patients were successfully treated. Among them, 18 patients (82%) had no bleeding. According to the classification of A, 15 patients (68%) had mild proctitis and 7(32%) experienced severe proctitis. Based on B classification, 9 patients (41%) were categorized as mild proctitis and 13(59%) as severe proctitis. Using the classification of A, the number of treatment sessions was significantly correlated with the endoscopic grade (or endoscopic total score)(Spearman’s r=0.86, P<0.001). Conclusions Preliminary evidence demonstrates that endoscopic APC combined with sub-mucosal injection of norepinephrine saline is not only effective for mild and moderate RP, but also maintains long-term efficacy for refractory RP. Modified endoscopy scoring system (A) assessment is more suitable for clinical application compared with B assessment.

OBJECTIVES: The association between concentrations of sulfur dioxide (SO), nitrogen dioxide (NO), carbon monoxide (CO), ozone (O), and emergency ambulance dispatches (EADs) for asthma was explored in the central Sichuan Basin of southwestern China for the first time. METHODS: EADs for asthma were collected from the Chengdu First-Aid Command Center. Pollutant concentrations were collected from 24 municipal environmental monitoring centers and including SO, NO, CO, daily 8-h mean concentrations of O (O-8 h), and particulate matter less than 2.5 μm in aerodynamic diameter (PM). The climatic data were collected from the Chengdu Municipal Meteorological Bureau. All data were collected from years spanning 2013-2017. A time-stratified case-crossover design was used to analyze the data. RESULTS: After controlling for temperature, relative humidity, and atmospheric pressure, IQR increases in SO (13 μg/m), NO (17 μg/m), and CO (498 μg/m) were associated with 18.8%, 11.5%, and 3.1% increases in EADs for asthma, respectively. The associations were strongest for EADs and SO, NO, and CO levels with 3-, 5-, and 1-day lags, respectively. CONCLUSIONS This study provides additional data to the limited body of literature for potential health risks arising from ambient gaseous pollutants. The results of the study suggest that increased concentrations of SO, NO, and CO were positively associated with emergency ambulance dispatches for asthma in Chengdu, China. Further studies are needed to investigate the effects of individual air pollutants on asthma.
Air Pollutants ; analysis ; toxicity ; Asthma ; chemically induced ; epidemiology ; Carbon Monoxide ; analysis ; toxicity ; China ; epidemiology ; Cities ; Cross-Over Studies ; Emergency Medical Dispatch ; statistics & numerical data ; Environmental Monitoring ; statistics & numerical data ; Humans ; Nitrogen Dioxide ; analysis ; toxicity ; Ozone ; analysis ; toxicity ; Particle Size ; Particulate Matter ; analysis ; toxicity ; Risk ; Sulfur Dioxide ; analysis ; toxicity