Analysis of reproductive damage in earthworms (Amynthas corticis) exposed to cypermethrin

Cypermethrin contamination was a potential threat to soil organisms. In the present work, reproductive damage in earthworms (Amynthas corticis) exposed to cypermethrin was investigated. It was found that earthworms could absorb and accumulate residual cypermethrin in soil, and also earthworm activities helped accelerate the degradation of cypermethrin in soil. The accumulation of cypermethrin in earthworms induced sperm damage, and cypermethrin not only caused the imbalance of calcium homeostasis in earthworm sperm cells by inhibiting earthworm sperm Ca²⁺-ATP and Ca²⁺-Mg²⁺-ATP enzyme activities but also caused barriers in acrosome reaction. It also affected sperm energy supply of earthworms by inhibiting the activity of Na⁺-K⁺-ATPase and Mg²⁺-ATPase of earthworm sperm. Meanwhile, the inhibition of acrosome enzyme activity of earthworm sperm by cypermethrin led to hinder fertilization and reduced cocoon production of earthworms, and the damage of cypermethrin to sperm of earthworm was a significant cause of its reproductive toxicity. The results of the evaluation of IBR index showed that reproductive toxicity of cypermethrin to earthworms reduced with the increasing time. The decreased reproductive toxicity of cypermethrin to earthworms at the later stage of exposure (42-56 d) might be due to a combination of reduced absorption of cypermethrin in soil by earthworms, decreased accumulation of cypermethrin in the body, and improved sperm capacitation.

Changes in peripheral blood natural killer T cells in hepatitis B e antigen-positive chronic hepatitis B patients and efficacy prediction after pegylated interferon therapy

We examined the expression of peripheral blood natural killer T (NKT) cells in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) patients and predicted its efficacy after pegylated interferon α-2a (Peg-INFα-2a) therapy. Sixty-three cases of HbeAg-positive CHB inpatients and outpatients, treated in the Third Xiangya Hospital of Central South University from January to December 2010, were administrated Peg-INFα-2a 18 myriad international unit intramuscularly once per week for 48 weeks. The number of peripheral NKT cells, 5 quantitative indicators of hepatitis B, and hepatitis B virus DNA capacity were detected at each time point. Forty-eight weeks after Peg-INFα-2a treatment, 26 HBeAg-positive CHB patients exhibited significant effects, 21 cases exhibited effects, and 16 cases showed no effects. The ratio of peripheral blood NKT cells in T lymphocytes before and 4, 8, and 12 weeks after treatment in the significant effect group was significantly increased compared to the effect group and no effect group (P < 0.01); at the 48th week of treatment and 24 weeks after the drug was withdrawn, NKT cell expression in the significant effect group was significantly higher than that in the effect group (t = 32.0, P < 0.01; t = 27.6, P < 0.01, respectively). A total of 27 patients showed HBeAg seroconversion until the 24th week after drug withdrawal. During treatment with Peg-INFα-2a in HBeAg-positive CHB patients, expression of peripheral blood NKT cells could be used to predict efficacy.