Preventive effects of N-acetyl-l-cysteine against imidacloprid intoxication on Bombyx mori larvae.

Imidacloprid, a widely used neonicotinoid insecticide, is toxic to silkworm (Bombyx mori). To explore whether N-acetyl-l-cysteine (NAC) has an effect on preventing silkworm (B. mori) from toxification caused by imidacloprid, we fed the fifth-instar larvae with mulberry leaves dipped in 200 mg/L NAC solution before exposing in imidacloprid, and investigated the silkworm growth, survival rate, feed efficiency, cocoon quality, and the activities of antioxidant enzymes in midgut. The results showed that addition of NAC could significantly increase body weight, survival rate, and feed efficiency of imidacloprid poisoned silkworm larvae (P < 0.05), as well as cocoon mass, cocoon shell mass, and the ratio of cocoon shell (P < 0.05). Furthermore, it could significantly promote the activities of the antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxide in the midgut of fifth-instar larvae under imidacloprid exposure at the late stage of treatment. In addition, it also could downregulate the malondialdehyde content. The results of our findings proved that the added NAC may have some beneficial effects on protection or restoration of antioxidant balance in imidacloprid exposed larvae.

Expression levels of receptor activator of nuclear factor-κB ligand and osteoprotegerin are associated with middle ear cholesteatoma risk.

CONCLUSION: Overexpression of receptor activator of nuclear factor-κB ligand (RANKL) and low expression of osteoprotegerin (OPG) are typical features in middle ear cholesteatoma patients. The altered RANKL/OPG protein ratio suggests that alterations in the RANKL-OPG pathway may be major factors in the pathogenesis of middle ear cholesteatoma. OBJECTIVE: Our meta-analysis explored the contribution of one important cytokine pathway, the RANKL and OPG pathway, in the development of middle ear cholesteatoma. METHODS: We screened Embase, the Cochrane Library, CISCOM, CINAHL, Google Scholar, China BioMedicine, China National Knowledge Infrastructure, PubMed, and Web of Science for relevant articles. RANKL expression and ratio of RANKL/OPG were analyzed using Comprehensive Meta-Analysis Version 2 software. RESULTS: The electronic literature search identified five studies that contained information on the correlation of RANKL and OPG expression with middle ear cholesteatoma. Increased RANKL expression positively correlated with middle ear cholesteatoma, while OPG expression showed an inverse association (p < 0.05). The ratio of RANKL/OPG in middle ear cholesteatoma cases was higher than in healthy controls, indicating that our observations are applicable to each individual case. Subgroup analysis based on country of study revealed that OPG levels decreased in China and Korea, and high RANKL expression was found in Poland, China, and Korea (all p < 0.05).