ABSTRACT
Objective To establish an animal behavioral model of tinnitus with step -down test ,and make use of the model to analyze the tinnitus genesis site in the salicylate-rats .Methods Forty wistar rats were includscl in this study ,they were randonly into 2 groups(experinent group and constrot group ,20 rats each group) .Ascertain that the animals treated with sodium salicylate(SS) have the sensation of tinnitus with the method of step -down test behavioral model .After having established a behavioral conditioned reflex ,subjects responded correctly to jump onto a climbing pole after hearing the sound .Then animals were under bilateral auditory nerves section ,to test whether the ablated-animals could still jump onto the pole after being treated with SS .Results Animals with the ab‐lating surgery could seldom jump onto the pole ,only reaching 1 .59 ± 0 .12 times average per 10 tests .Compared with con‐trol group ,there were significant differences with t-Test (P<0 .05) ,suggesting that subjects could not hear the tinnitus after the surgery .Conclusion Sodium salicylate could not make the animals with bilateral auditory nerves section to have the sensation of tinnitus .The peripheral auditory system plays an extremely important role in salicylate-induced tinnitus .
ABSTRACT
A 55 year old man complained of a painless mass at the left maxillofacial region. The mass had continuously grown over 10 years. Upon physical examination a cystic mass with size of 5 cm in length with bulging smooth surface was seen on the left maxillofacial region. Computed tomography (CT) scan showed a giant cyst with bone destruction and invasion in the left maxilla, maxillary sinus and nasal cavity. Needle aspiration of the mass yielded 80 milliliter of brown fluid. The excisional biopsy was made which revealed ghost cells and dysplastic dentin that were features of dentinogenic ghost cell tumor. Finally, a dentinogenic ghost cell was diagnosed.