Apoptosis Progression in the Hair Cells in the Organ of Corti of GJB2 Conditional Knockout Mice

OBJECTIVES: Apoptosis may play an important role in the mechanism underlying the GJB2 gene conditional knockout (cCx26) mice cochlear cell death. The objective of this study was to explore the the damage mode of the outer hair cells (OHCs) and its real time point of apoptosis and provide information to further explore the role of apoptosis in the happening of hearing loss in cCx26 mice. METHODS: Cochleae from mice at various developmental stages (P8, P12, and P21) were dissected out and first used to be observed under the scanning electron microscope (SEM). Basilar membranes from mice at P8, P14, P18, and P21 were stained by fluorescein isothiocyanate-conjugated phalloidin and propidium iodide (PI) and examined under confocal microscope. RESULTS: The loss of OHCs of cCx26 knockout mice was first set between P12 and P21 under SEM. Whole mount phalloidin and PI staining revealed that obvious apoptotic appearance of the OHCs surface morphology was observed at P18. CONCLUSION: Typical apoptotic morphology was found in the OHCs in the organ of Corti of the cCx26 mice at P18. This may provide information to further study the role of apoptosis in the occurrence of hearing loss of cCx26 mice.

Construction of GJB2 mutations common in Chinese EGFP fusion protein vectors / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To construct GJB2 gene mutations common in Chinese EGFP fusion protein vectors, and to search for better way to study the mechanism of deletion mutations in GJB2 gene.@*METHOD@#Non-fusion protein vectors of 235delC, 299-300 del AT and 176 del 16 bp were first made by point mutation methods in vitro. Then expression part of the upper 3 mutations were amplified by PCR and the PCR products were cloned into TA cloning vector. After cutting by restriction enzymes EcoRI/BamHI, three deletion mutations were inserted into pEGFP-N1 vector. Sequencing was used to verify the validity of the fusion protein vectors. HEK293 cells were transfected with the recombinant DNA samples by the liposome complex method.@*RESULT@#The recombined plasmids were highly expressed in HEK293 cells. Green fluorescence signals were distributed uniformly in cytoplasm.@*CONCLUSION@#GJB2 mutations common in Chinese EGFP fusion protein vectors were constructed successfully. It may provide a better way to explore the reasons of nonsyndromic hearing loss common in Chinese.

Construction of GJB2 mutations common in Chinese EGFP fusion protein vectors / 临床耳鼻咽喉头颈外科杂志

Objective:To construct GJB2 gene mutaitons common in Chinese EGFP fusion protein vectors, and to search for better way to study the mechanism of deletion mutaitons in GJB2 gene. Method: Non-fusion protein vectors of 235delC, 299-300 del AT and 176 del 16 bp were first made by point mutaiton methods in vitro. Then expression part of the upper 3 mutations were amplified by PCR and the PCR products were cloned into TA cloning vector. After cutting by restriction enzymes EcoRI/BamHI, three deletion mutaions were inserted into pEG-FP-N1 vector. Sequencing was used to verify the validity of the fusion protein vectors. HEK293 cells were trans-fected with the recombinant DNA samples by the liposome complex method. Results The recombined plasmids were highly expressed in HEK293 cells. Green fluorescence singals were distributed uniformly in cytoplasm. Conclusion; GJB2 mutations common in Chinese EGFP fusion protein vectors were constructed successfully. It may provide a better way to explore the reasons of nonsyndromic hearing loss common in Chinese.

Fragile histindine triad gene and carcinomas of the nasal cavity and paranasal sinus / 中国耳鼻咽喉头颈外科

OBJECTIVE To investigate the genetic abnormalities of FHIT gene in nasal and paranasal sinus carcinoma, and to explore its relationship between genetic abnormalities of FHIT gene and etiology of nasal and paranasal sinus carcinoma(NPSC). METHODS The clinical data of 48 patients with NPSC treated with radical operations from 1991 to 2000 were studied retrospectively. Patients included 23 female and 25 male ranging in age from 20 to 71 years. Immunohistochemistry with SP method was used to assess the expression of FHIT in the carcinoma specimens of the patients. Microdissection and denaturating high-performance liquid chromatography (DHPLC) were used to analyze the loss of hereteozygosity (LOH) of DS1234 in exon 8 of FHIT gene. RESULTS The loss of expression of FHIT was found in 5 patients(10.4 %, 5/48). Comparing with adjacent non-neoplastic tissue, reduced expression of HFIT was found in 16 (55.17 %, 16/29) patients. The adenoid cystic carcinoma showed stronger expression of FHIT than squamous cell carcinoma(P