Aim To explore the change of mGluR1α and mGluR5 expression in brain CA1 region after infrasonic action, and the role of antagonist MCPG in rats. Methods 160 SD rats were divided randomly into infrasonic damage group and MCPG therapy group. The two groups were subdivided into control group and 1-time, 7-time and 14-time groups respectively. Rats were exposed to 8Hz, 130dB infrasound two hours each time. Expression of mGluR1α and mGluR5 were detected by immunohistochemical staining and in situ hybridization methods. The morphological changes of neurons after MCPG therapy were observed under microscopes. Results Comparing with the control group, the number and the A value of mGluR1α and mGluR5 positive cells changed after one infrasonic action(P∨ 0.05); and the expression of mGluR1α and mGluR5 in the 7-time group were most obvious(P∨ 0.01); in the 14-time group, they recovered already to normal level. Morphological study confirmed that MCPG protected neurons from infrasonic damage. Conclusion Change of mGluR1α and mGluR5 activity can mediate exciting neurotoxicity after infrasonic action, and it is one of the major factors relative to neurons injury, MCPG had an protective effect on brain damage caused by infrasound.

OBJECTIVE To discuss the surgical methods and their long term efficacy of management of the parotid tumor.METHODS The clinical data of 86 cases with parotid tumor underwent operation between 1997 and 2004 in our hospital were retrospectively analyzed.There were 53 male and 33 female with their age from 23 to 84 years(mean 57 years old). All the patients underwent superficial parotidectomy or extensive superficial parotidectomyenl or total parotidectomy.Selective or functional neck dissection was carried out in some cases.The function of facial nerve was evaluated after operation in all patients. Postoperative radiotherapy was performed in all malignant cases with a dose of 50 to 70 Gy.The patients were followed-up for 36 to 120 months.RESULTS There were 73 benign cases and 13 malignant cases. Five of 8 malignant tumors were found in deep lobe gland.Only one benign tumor locally recurred.The local- regional control rate of the benign tumor was 98.3%. The 3-year survival rate and local-regional control rate in malignant neoplasm were 69.2 % and 84.6 % respectively.The cervical lymph nodes metastasis rate was 23.1% in postoperative pathologic study.The facial nerve preservation rates were 97.3 % and 69.2 % in benign and malignant cases respectively.CONCLUSION The superficial parotidectomy is the basic surgical method.Extensive superficial parotidectomy or total parotidectomy can be used if necessary.The facial nerve and its branches should be preserved during operation. The malignant tumor is more frequently found in deep lobe of the parotid gland.