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 .

Objective To study the tissue-specificity of ?-carotene-15,15’-monooxygenase(? CMOOX). Method Semi-quantitative RT-PCR and HPLC were used to study the expression of ?CMOOX mRNA and its activity in different tissues of chicken. Results ?CMOOX mRNA was expressed in tissues including heart, liver, spleen, lung, kidney, duodenum, jejunum, ileum, muscle and testis, not expressed in lung. Furthermore, it was expressed in jejunum with the highest level. ?CMOOX activity was found in every tissue, except lung, and highest in duodenum and jejunum. Conclusion The distribution of ?CMOOX in chicken has tissue specificity.

OBJECTIVETo investigate the cloning and expression of Treponema pallidum (TP) specific antigen TpN17 and an epitope of TpN44.5 and the clinical application of this fusion antigen.

METHODSTpN17 gene was amplified from the genome of TP and an epitope of TpN44.5 was spliced to the 5' end of TpN17 gene. This modified TpN17 gene was cloned into the expression vector pGEX4T-2. The recombinant fusion antigen was purified by affinity chromatography and then an enzyme-linked immunosorbent assay (ELISA) kit was prepared. With this kit, the sera of 10 normal persons and 10 TP patients were tested.

RESULTSThe molecular weight of the purified fusion antigen was 45,000. Tested with ELISA, 10 serum samples of the TP patients were positive and another 10 of the normal persons were negative. ELISA equipped with the GST-epi-TpN17 antigen showed higher sensitivity and specificity as compared with routine methods.

CONCLUSIONThe recombinant fusion TP specific antigen GST-epi-TpN17 was suitable for the preparation of ELISA kit in clinical examinations.

Antigens, Bacterial ; biosynthesis ; genetics ; Cloning, Molecular ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunodominant Epitopes ; Polymerase Chain Reaction ; Recombinant Fusion Proteins ; biosynthesis ; Sensitivity and Specificity ; Syphilis ; diagnosis ; Treponema pallidum ; immunology