OBJECTIVE To study the causes and mechanism of auditory neuropathy. METHODS Auditory neuropathy is characterized by the DPOAE being normal, the shape of the pure tone loss being mostly in low frequencies, but the ABR being absent or the threshold elevated disproportionally to the pure tone threshold. Patients were screened from the deaf patients through asking the ill history and taking the exams of pure tone audiometry, auditory brain stem response, distortion product of otoaccoustic emissions (DPOAE). Thirty six patients were met the above standard. Deparaffined sections of cochlea of the guinea pigs were used as antigens to test whether the sera of patients had the autoantibodies with immunofluorescence method. RESULTS In the total of 36 patients with this type of hearing loss, autoantibodies were positive in 31 patients(86.1%). Twenty of the 31 patients had autoantibodiesto connective tissue of osseous spiral lamina where the nerve fiber connecting the hair cells and spiral ganglion cells go through. The autoantibodies to capsula surrounding the spiral ganglion and inner ear nerve fiber was also seen in these patients. In additional 7 patients, the autoantibodies to spiral ganglion cell nucleus and inner ear nerve fiber was detected. In the 44 control persons, 9.1% of them have the autoantibodies to inner ear tissues(P

OBJECTIVE: To determine GJB2 allelic mutant and estimate probability of hereditary hearing loss in newborn with GJB2 heterozygous mutation in Beijing. METHOD: We performed genetic testing for sequencing of GJB2 gene for searching GJB2 allelic mutant in 915 newborn who received newborn deafness gene screening (GJB2 c. 235delC, GJB2 c. 299_300delAT, GJB2 c. 176191del16, GJB2 c. 35delG) in Beijing Tongren hospital, and the mutation were classified to pathogenic mutation,undefined variant and polymorphism. RESULT: Four hundred (43.72%, 400/915) newborn were detected to carry at least one mutation allele in GJB2. 3 (0.33%, 3/915) newborn had pathogenic mutations (c. 94C>T, c. 380G>T, c. 344T>G); 62 (6.76%, 62/915) newborn carried 14 undefined variant, 36 newborn had c. 109G>A (58.06%, 36/62),13 newborn had c. 368C>A (20.97%,13/62), six (c. 268C>G, c. 282C>T, c. 294G>C, 456C>T, c. 501G>A, c. 587T>C) are novel; 335 (36.61%, 335/915) newborn were polymorphism. CONCLUSION The probability of hereditary hearing loss is 7.09% in newborn with GJB2 heterozygous mutation in Beijing. It is noteworthy that c. 109G>A, c. 368C>A occupy a high proportion.
Alleles ; Beijing ; Connexin 26 ; Connexins ; genetics ; DNA Mutational Analysis ; Deafness ; genetics ; Genetic Testing ; Heterozygote ; Humans ; Infant, Newborn ; Mutation ; Neonatal Screening ; Polymorphism, Genetic

OBJECTIVE To analyze for mutations of the PDS gene in patients with sensorineural hearing loss associated with enlarged vestibular aqueduct and analyze the molecular pathogenesis of enlarged vestibular aqueducts. METHODS Eighteen sporadic cases of large vestibular aqueduct syndrome and twelve control individuals with normal hearing were included in this study. Exons 6 and 9 of the PDS gene in all subjects were amplified by polymerase chain reaction and analyzed by direct DNA sequencing. RESULTS Analysis revealed 2 single base changes in exon 6 of one patient with large vestibular aqueduct syndrome. One was a G→C transversion at nucleotide position 611, and the other was a T→G transversion at nucleotide position 612, resulting in a predicted Gly→Ala substitution at position 204. No mutation in exons 6 and 9 of the PDS gene was found in the PDS gene of the control individuals. CONCLUSION Mutations of the PDS gene are responsible for the large vestibular aqueduct syndrome. Analysis of the PDS leftover sequence in patients with large vestibular aqueduct syndrome is the next step in elucidating the complicated causes of this disease.

OBJECTIVE To understand the function of MMP-2 and TIMP-2 and the relationship among expression of MMP-2, TIMP-2 and microvessel density in laryngeal carcinomas. METHODS The expression of MMP-2, TIMP-2 and CD34 in 37 laryngeal carcinomas patients were studied with immunohistochemical staining. The staining results were studied morphometrically with computer image analysis. RESULTS The mean values of MMP-2 expression and microvessel density (MVD) in squamous cell carcinoma group with lymph node metastasis were significantly higher than that without lymph node metastasis (P

Objective To determine the audiological characteristics in 832 deaf children with biallelic causative mutations in GJB2 ,SLC26A4 gene .Methods The 832 patients received deafness gene screening ,553 were GJB2 gene biallelic causative mutations ,279 were SLC26A4 gene biallelic causative mutations .Patients were divided into four groups according to ages of hearing loss onset :<1 ,1~3 ,3~6 ,6~12 years old ,and the audiological character-istics and prevalence of GJB2 ,SLC26A4 gene mutations at different ages of onset .Results The prevalence of GJB2 gene mutations at four groups was 37 .97% (210/553) ,38 .34% (212/553) ,16 .27% (90/553) ,7 .41% (41/553) ,re-spectively ;the prevalence of SLC26A4 gene mutations at four groups was 25 .45% (71/279) ,44 .80% (125/279) , 20 .07% (56/279) ,9 .67% (27/279) ,respectively .The difference between GJB2 and SLC26A4 gene was significant(P=0 .001) .The prevalence of profound hearing loss with GJB2 gene mutations at four groups were 66 .67% (140/210) ,61 .32% (130/212) ,47 .78% (43/90) ,41 .46% (17/41) ,respectively .The difference was significant (P=0 .004) ,while the difference in 279 patients with SLC26A4 gene mutations was not statistically significant (P= 0 . 083) .Conclusion The age of hearing loss onset in patients with biallelic causative mutations in GJB 2 or SLC26A4 gene refers to 0~3 years -old ,hearing loss in patients with GJB2 ,SLC26A4 gene mutations gives priority to pro-found .The age of hearing loss onset is smaller ,the ratio of profound hearing loss is higher .Patients with severe and profound hearing impairment should be performed the genetic testing when the age of onset under 12 .