Objective: To investigate the role and mechanism of action of green tea polyphenols in noise-induced hearing loss. Methods: Male specific pathogen-free guinea pigs were randomly divided into normal control group with 9 guinea pigs, noise exposure group with 36 guinea pigs, and green tea polyphenol intervention group with 36 guinea pigs. Auditory brainstem response (ABR) threshold shift was examined before noise exposure and at 1, 3, 7, and 14 days of noise exposure. The surface preparation of cochlear basilar membrane was used for hair cell count and the morphology of hair cells was also observed. Western blot was used to observe the expression of cysteinyl aspartate-specific protease-9 (caspase-9) and cysteinyl aspartate-specific protease-3 (caspase-3) in cochlear tissue. Results: Both the noise exposure group and the green tea polyphenol intervention group had an increase in ABR threshold after noise exposure, and the green tea polyphenol intervention group had a significantly lower ABR threshold shift than the noise exposure group at all time points (P<0.05). Both groups had enlargement, atrophy, or loss of hair cells after noise exposure, and at 7 and 14 days of noise exposure, the noise exposure group had a significantly higher rate of abnormal hair cells than the green tea polyphenol intervention group (P<0.05). Both groups had an increase in the expression of caspase-9 and caspase-3 after noise exposure, and the noise exposure group had a significantly greater increase than the green tea polyphenol intervention group (P<0.05). Conclusion Green tea polyphenols can reduce noise-induced hearing loss and hair cell injury, possibly by regulating the expression of caspase-9 and caspase-3.

OBJECTIVETo evaluate the safety, immunogenicity and fit dosage of Healive inactivated hepatitis A vaccine (HAV) in children.

METHODSA total of 85 susceptible aged 4 - 10 years with HAV seronegative children, had been enrolled from two adjacent villages in a county. The volunteers were randomized allocated into two groups and to receive a priming dose of 250 U/0.5 ml/dose or 500 U/1.0 ml/dose of Healive vaccine, produced by Sinovac Biotech Co, Ltd. A booster of the same dose was given at 12th month. Local and systemic side effects were examined and seroconversion rate as well as geometric mean titers of anti-HAV antibody were tested at 3-week, 12-month after the primary dose and at 1 month after the booster dose.

RESULTSThe vaccine was well tolerated in both groups. At 21 days after the primary dose, the seroconversion rates were 94.4%, 100.0% and geometric mean titers (GMT) were 195 mIU/ml and 370 mIU/ml in 250 U and 500 U groups respectively. At 12 months after the primary dose, the seroconversion rate of anti-HAV was 100.0%, and GMT raised to 361 mIU/ml, 456 mIU/ml (P > 0.05) respectively. One month after the booster dose, GMT raised to 14 893 mIU/ml, 21 696 mIU/ml.

CONCLUSIONGMT of the 0, 12 month schedule was higher than other schedule after the booster vaccination. The Healive inactivated vaccine can be used for emergency vaccination. The Healive inactivated vaccine produced by Sinovac Company Ltd was safe and highly immunogenic. Two hundred and fifty U/dose was considered appropriate for children.

Child ; Child, Preschool ; Dose-Response Relationship, Immunologic ; Drug Administration Schedule ; Hepatitis A ; immunology ; prevention & control ; Hepatitis A Antibodies ; analysis ; Hepatitis A Vaccines ; administration & dosage ; immunology ; Humans ; Vaccines, Inactivated ; administration & dosage ; immunology