Résumé
Objective@#To investigate the effect of silica dust on protein oxidative injury in the lung tissue of mice.@*Methods@#A total of 60 mice were randomly divided into control group (not exposed to dust) , 2-hour group (inhalation of dust for 2 hours per day) , 4-hour group (inhalation of dust for 4 hours per day) , and 8-hour group (inhalation of dust for 8 hours per day) , with 15 mice in each group. During dust exposure, the mice were placed in a dust exposure cabinet; the dust was blown with an air blower and the concentration was maintained at 125 mg/m3. All mice were exposed to silica dust for 3 weeks. The changes of the lung were observed after dust exposure ended, and spectrophotometry was performed to measure the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) and protein carbonyl in the lung tissue.@*Results@#The 2-, 4-, and 8-hour groups had marked edema, sporadic punctate hemorrhage, and nodular shadow in the lungs. Compared with the control group, the 2-, 4-, and 8-hour groups had a significant increase in lung coefficient (7.03±0.78 mg/g, 8.48±0.93 mg/g, and 8.99±0.85 mg/g vs 5.52±0.81 mg/g, P<0.05) . Compared with the control group, the 2-, 4-, and 8-hour groups had significant increases in the content of MDA (2.83±0.52, 3.94±0.65, and 4.56±0.77 nmol/mg prot vs 1.26±0.36 nmol/mg prot, P<0.05) and protein carbonyl (1.61±0.44, 1.96±0.47, and 2.20±0.58 nmol/mg prot vs 1.13±0.21 nmol/mg prot, P<0.05) in lung tissue. The 4- and 8-hour groups had a significantly lower activity of SOD than the control group (153.69±20.58 and 140.35±18.97 U/mg prot vs 186.00±25.46 U/mg prot, P<0.05) .@*Conclusions@#Silica dust may lead to protein oxidative injury in the lung tissue of mice, which might play an important role in lung injury.
Résumé
A device of subcutaneous embedding contraceptive is that the contraceptive filling in a rod-shape capsule made by high molecular compound is slowly and stably released. The released contraceptive takes the effect via blood circulation. Subcutaneous embedding contraceptive is characterized by high performance, long-term efficacy, safety, convenience, and high reversibility; therefore, it is popular among reproductive-aged women. On the other hand, it has few of segmentation during taking out of human body. However, side effects still need to be further studied. This study introduced the biological characteristics and complications of non-biodegradable and biodegradable long-term sustained release vector for contraception, thus we hope discover a new subcutaneous embedding contraceptive involving in excellent performance and few side effects for clinical application.