[The value of otolith function test in the prognosis of sudden sensorineural hearing].

OBJECTIVE: To evaluate the characteristics and prognosis of sudden sensorineural hearing loss through vestibular evoked myogenic potentials. METHOD: Fifty patients with unilateral sudden hearing loss underwent an ear test battery, including audiometry, cervical vestibular evoked myogenic potential (cVEMP) and ocular vestibular evoked myogenic potential(oVEMP). The cVEMP and oVEMP in patients with sudden sensorineural hearing loss were investigated. Their associations with initial hearing threshold, the type of audiogram, the results of coloric test and hearing recovery were also accessed. RESULT: After one-month treatment, the average threshold declined significantly in affected ears, with normal VEMP rates improved significantly (P < 0.05). Initial hearing threshold and hearing recovery were significantly associated with the results of coloric test and the results of VEMP test (P < 0.05). CONCLUSION: Our study indicated that vestibular evoked myogenic potential examination was not only a useful additional diagnostic tool in the neurotological evaluation of patients suffering sudden hearing loss, but also very valuable in the prognosis of sudden sensorineural hearing loss.

[Correlation of diffusion tensor imaging between the cerebral cortex and speech discrimination in presbycusis].

OBJECTIVE: To investigate the relationship between pure-tone average (PTA), the fractional anisotropy (FA) of the auditory pathway, cognitive cortex and auditory cortex in presbycusis. METHOD: Twenty-five elderly subjects with presbycusis were participated in the study. PTA, speech discrimination abilities were evaluated in each subject. Diffusion tensor imaging (DTI) was applied to access the FA of the IC, the superior frontal gyrus and the Heschl's gyrus. Compare the difference between two sides of the values of FA in the three areas. Bivariate correlation analysis was performed to evaluate the effects of PTA and FA of the inferior colliculus (IC), the superior frontal gyrus and the Heschl's gyrus on speech discrimination abilities. RESULT: There were no significant differences between the left and right side of the inferior colliculus (P > 0.05). Higher FA values were recorded at the left side of the Heschl's gyrus and the superior frontal gyrus (P < 0.05). Both PTA and the FA of the superior frontal gyrus have a negative association with speech discrimination abilities (P < 0.01, P < 0.05), while the FA of the Heschl's gyrus has a positive association with speech discrimination abilities (P < 0.05). CONCLUSION: Our findings indicated that the speech discrimination abilities of the elderly is not only related to the peripheral auditory function, but also to the central auditory and cognitive function.

[Mutational analysis of candidate genes in a Chinese pedigree with dominantly inherited auditory neuropathy].

OBJECTIVE: Three genes including the OTOF, the DFNB59 and the DIAPH3 have been implicated previously in human non-syndromic auditory neuropathy. In this study, we aim to investigate whether DIAPH3 gene or the known deafness loci of 25 cloned autosomal dominant deafness (DFNA) genes contribute to the nonsyndromic hearing loss of a Chinese pedigree with dominantly inherited auditory neuropathy (AN). METHOD: Nine members of the kernal pedigree in this family were selected. Genomic DNA was isolated from the peripheral leukocytes of the subjects using the Puregene DNA Isolation Kits. Firstly, the 5'UTR of DIAPH3 gene was PCR amplified in all subjects. Then, the DNA fragments spanning the entire coding regions of DIAPH3, GJB2 and GJB3 genes, and 50 exons in other 23 cloned DFNA genes were amplified using specific primers. Each fragment was purified and analyzed by direct sequencing. The resultant sequence data were compared with the standard sequence to identify deafness-associated mutations. RESULT: PCR amplifications were successfully conducted. We failed to detect the presence either of c. --172G > A mutation in the 5'UTR that have been reported, or any other deafness-associated mutations in the whole DIAPH3 gene, by sequence analysis. We also did not find any known deafness-causing mutations among the 25 cloned DFNA genes. CONCLUSION: The DIAPH3 gene, and the known deafness loci of 25 cloned DFNA genes seem not contribute to the pathogenesis of this Chinese AN family in this study, which suggesting new gene(s) involvement.

[Determination of 46 plasticizers in food contact polyvinyl chloride packaging materials and their migration into food simulants by gas chromatography-mass spectrometry].

A gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of 46 plasticizers in food contact polyvinyl chloride (PVC) packaging materials and their migration into food simulants, i. e. water, 3% acetic acid, 10% ethanol and olive oil. Plasticizers in the PVC packaging materials, aqueous food simulants and olive oil food simulants were extracted by the dissolution-precipitation, liquid-liquid extraction and gel permeation chromatography (GPC) approaches, respectively. The extracts were analyzed by GC-MS in selective ion monitoring (SIM) mode and quantified using the external standard method. The cal-ibration curves were linear in the ranges of 0.1-2.0 mg/L with the correlation coefficients of 0.9910-0. 999 9. The limits of detection were from 0. 005 mg/kg to 0. 05 mg/kg ( S/N = 5 ). The recoveries at 3 spiked levels were 69.51%-107. 21% and the relative standard deviations (RSDs n = 6) ranged from 3.53% to 18.95%. These results show that this method is fast, sensitive and accurate for the qualitative and quantitative determination of plasticizers in food contact plastic products and 4 types of food simulants.