Long-term efficacy of a rural community-based integrated intervention for prevention and management of chronic obstructive pulmonary disease: a cluster randomized controlled trial in China's rural areas

This study aimed to assess the efficacy of a rural community-based integrated intervention for early prevention and management of chronic obstructive pulmonary disease (COPD) in China. This 18-year cluster-randomized controlled trial encompassing 15 villages included 1008 patients (454 men and 40 women in the intervention group [mean age, 54 ± 10 years]; 482 men and 32 women in the control group [mean age, 53 ± 10 years]) with confirmed COPD or at risk for COPD. Villages were randomly assigned to the intervention or the control group, and study participants residing within the villages received treatment accordingly. Intervention group patients took part in a program that included systematic health education, smoking cessation counseling, and education on management of COPD. Control group patients received usual care. The groups were compared after 18 years regarding the incidence of COPD, decline in lung function, and mortality of COPD. COPD incidence was lower in the intervention group than in the control group (10% vs 16%, <0.05). A decline in lung function was also significantly delayed in the intervention group compared to the control group of COPD and high-risk patients. The intervention group showed significant improvement in smoking cessation compared with the control group, and smokers in the intervention group had lower smoking indices than in the control group (350 vs 450, <0.05). The intervention group also had a significantly lower cumulative COPD-related death rate than the control group (37% vs 47%, <0.05). A rural community-based integrated intervention is effective in reducing the incidence of COPD among those at risk, delaying a decline in lung function in COPD patients and those at risk, and reducing mortality of COPD.

Studies on the use of cobalt-60 irradiation to control infectivity of Toxoplasma gondii cysts.

Mouse brains harboring the Chinese NT strain of Toxoplasma gondii cysts were homogenized with normal saline and irradiated with cobalt-60 gamma rays at various doses. The homogenate was introduced intraperitoneally into NIH mice or per os into kittens. Loss of infectivity was confirmed according to the following criteria: no cyst found in mouse brain impression smears on the 50th day after inoculation; no oocyst found in feces of kittens 3-15 days after inoculation; subinoculation in mice and a negative IHA test. All bioassays, parasitological examinations and serological tests in the control group gave positive results. Activity of radioactive source: 10 KCi; uniform dosage: 1238 rad/min; dose range of irradiation: 0.1-1.0 KGy. Minimal effective dose of gamma rays to control infectivity of T. gondii cysts was 0.55 KGy. Infectivity of bradyzoites irradiated with gamma rays at a dose of 0.45 KGy decreased by 10,000 times. Minimal effective dose of gamma rays to control infectivity of American ME-49 and Ts-2 strain, is slightly higher (0.6KGy) than that of NT strain. These studies present useful data for practical use of cobalt-60 to control infectivity of T. gondii in meat products.