[Efficacy of CO2 laser in the treatment of precancerous laryngeal lesions under phonomicrosurgery and its relative factors].

OBJECTIVE: To investigate the efficacy of CO2 laser treatment for patients with precancerous laryngeal lesions under phonomicrosurgery and to explore the points for attention in operation. METHOD: They were all treated with phonomicrosurgery techniques as mucosal epitheliumablation or mucosal stripping by using CO2 laser. Eight patients with laryngeal papilloma were excised by CO2 laser. RESULT: All patients were treated with CO2 laser surgery successfully. During follow-up of 6 to 39 months, all patients survived. Local recurrence or canceration were detected in 3 cases, of which 2 cases with laryngeal papilloma underwent CO2 laser treatment in one year post-operatively, while the other case with severe dysplasia underwent laryngeal vertical partial laryngectomy and post-operative radiotherapy one and half year postoperatively due to canceration. No local recurrence occurred until the last follow up. No severe complications such as dyspnea and hemorrhage occured. CONCLUSION: CO2 laser surgery is an effective and minimally invasive treatment for precancerous laryngeal lesions. Through selecting the appropriate patient and paying attention to the operation during surgery, the adhesion of vocal cord can be reduced or even be avoided after CO2 laser surgery.

[Research of the electrophysiological properties of acutely dissociated spiral ganglion neurons isolated from mice using patch clamp technique].

OBJECTIVE: To explore the electrophysiological properties of spiral ganglion neurons (SGN) isolated from neonatal mice. METHODS: Ion channel currents of acutely trypsin-dissociated spiral ganglion neurons was recorded and analyzed using whole-cell variation of the voltage clamp technique. RESULTS: In the membrane of SGN, we recorded tetraethylammonium (TEA)-sensitive and 4-aminopyridine (4-AP)-sensitive outside delayed rectifier potassium currents, A-type potassium currents and tetrodotoxin-sensitive inside sodium currents. Ion channel activity had the character of voltage-dependence. Some cells, which did not exhibit sodium currents exhibited, delayed rectifier potassium currents. CONCLUSIONS: The electrophysiological properties of acutely dissociated spiral ganglion neurons could be reference to the research of the mechanics of auditory propagation and the ion channel pharmacology.

[Establishment of methods of mechanical dissociation and culture of spiral ganglion neurons in postnatal mice].

OBJECTIVE: To conduct a study on the methods for establishing a cytological model of mechanical dissociation and culture of spiral ganglion neurons (SGNs) in postnatal mice. METHODS: The spiral ganglion neurons were taken from 1-6-day old mice for primary culture. The morphology and the process of axon were observed by use of an inverted/phase contrast microscope. Immunocytochemical identification was performed using fluorescent microscopy. RESULTS: In the state of primary culture in vitro, the SGNs were found to have good cell morphology and axon regeneration power, the surviving cells of SGN(5-7 d) amounted to (78.10 +/- 4.33)/cm2 and the survival period was 7-14 d. CONCLUSION: We successfully established the methods of mechanical dissociation and culture of SGN cytological model; the cell amount and survival period of SGNs were able to meet the requirement of cytological experiments.