Viral-mediated expression of c-Myc and cyclin A2 induces cochlear progenitor cell proliferation.

Cochlear progenitor cells have a limited proliferative capability, which prevents their application in treating sensorineural hearing loss. In this study, we showed that the expression of c-Myc and cyclin A2 was down-regulated during the development of cochlear tissue and CPC differentiation. Over-expression of these two genes using adenovirus transduction, significantly affected the CPC cell cycle and promoted the CPC proliferation. We further demonstrated that this promotion involves the classic CKI-cyclin-CDK pathway. Our study suggests that genetically modified CPCs may be a promising cell source for cochlear stem cell transplantation that improves the efficacy of cell therapy.

[One case of pleomorphic adenoma originates from inferior nasal turbinate].

Pleomorphic adenoma (PA) is the most common benign tumor of the salivary glands. Originating from the nasal cavity is very rare. This paper reports one case of pleomorphic adenoma of the inferior nasal turbinate to analyze the clinic characteristic of this disease. Although these tumors are rarely seen in everyday practice, one should consider this possibility as an uncommon aetiology when confronted with an intranasal mass.

GJB2 mutation spectrum in 2,063 Chinese patients with nonsyndromic hearing impairment.

BACKGROUND: Mutations in GJB2 are the most common molecular defects responsible for autosomal recessive nonsyndromic hearing impairment (NSHI). The mutation spectra of this gene vary among different ethnic groups. METHODS: In order to understand the spectrum and frequency of GJB2 mutations in the Chinese population, the coding region of the GJB2 gene from 2063 unrelated patients with NSHI was PCR amplified and sequenced. RESULTS: A total of 23 pathogenic mutations were identified. Among them, five (p.W3X, c.99delT, c.155_c.158delTCTG, c.512_c.513insAACG, and p.Y152X) are novel. Three hundred and seven patients carry two confirmed pathogenic mutations, including 178 homozygotes and 129 compound heterozygotes. One hundred twenty five patients carry only one mutant allele. Thus, GJB2 mutations account for 17.9% of the mutant alleles in 2063 NSHI patients. Overall, 92.6% (684/739) of the pathogenic mutations are frame-shift truncation or nonsense mutations. The four prevalent mutations; c.235delC, c.299_c.300delAT, c.176_c.191del16, and c.35delG, account for 88.0% of all mutantalleles identified. The frequency of GJB2 mutations (alleles) varies from 4% to 30.4% among different regions of China. It also varies among different sub-ethnic groups. CONCLUSION: In some regions of China, testing of the three most common mutations can identify at least one GJB2 mutant allele in all patients. In other regions such as Tibet, the three most common mutations account for only 16% the GJB2 mutant alleles. Thus, in this region, sequencing of GJB2 would be recommended. In addition, the etiology of more than 80% of the mutant alleles for NSHI in China remains to be identified. Analysis of other NSHI related genes will be necessary.

[Characteristics of respiratory disturbance during REM sleep in OSAHS].

OBJECTIVE: To study the characteristics of respiratory disturbance during REM sleep in OSAHS through the signals surveyed by polysomnography (PSG). METHOD: The result of sleeping monitoring of 180 cases with OSAHS by PSG was reviewed, the AHI and the RIT index was used to evaluate the severity in different sleep stage as in REM and N-REM stage to find out the characteristics of the respiratory disturbance. RESULT: The study showed that AHI index in mild group increased greatly in REM period (P < 0.05), but no significant changes between the moderate and severe groups. And the lowest oxygen saturation (LSaO2) was lower during REM stage than that during N-REM stage (P < 0.05). CONCLUSION: (1) The time of REM in OSAHS patients often decreases according to their severity. (2) The respiratory disturbance during the stage REM is much severe than during the stage N-REM. The main manifestation is that the time of apnea-hypopnea is more longer and the AHI index does not significantly change. (3) The RIT index is more closely related to the severity of respiratory disturbance than AHI index.

[Ruby laser arytenoidectomy in the treatment of bilateral vocal cord paralysis].

OBJECTIVE: To explore endoscopic ruby-laser arytenoidectomy for the treatment of bilateral vocal cord paralysis. METHOD: Ten cases with bilateral vocal cord paralysis were operated, six were male and four were female, all of whom had Ruby laser arytenoidectomy with tracheostomy and anesthesia through intubiting ahead. RESULT: There are no complications. During the following three to thirteen months, all patients operated breathed well with no synecdochical scar formed in the throat and their pronounciation improved apparently. Their glottis are broadened more than 4 mm after operation. CONCLUSION: Ruby-laser arytenoidectomy is a practicable therapy to bilateral vocal cord paralysis.