Expression of Fibronectin Activities in Rat Tongue Mucosal Wound Healing Following CO2 Laser Incision / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The CO2 laser is commonly used in the oral cavity and pharyngolaryngeal lesion, since, unlike the conventional scalpel technique, it provides excellent hemostasis and visualization and thus enables the surgeon to operate in a precise manner. Additional advantages include decreased postoperative pain and less swelling. Despite this advantage, several studies have reported impaired wound healing associated with the use of CO2 laser. Fibronectin is a high molecular weight glycoprotein and serves as a substrate for adhesion and migration of cells which repair cell defects together with fibrin. Fibronectin is involved in the generation of reticulin matrix together with the type III collagen. MATERIALS AND METHODS: The histological changes and the expression of fibronectin activities following incision of tongue mucosa by the CO2 laser and the conventional scalpel technique were compared over a period of 7 days in a rat model. RESULTS: A delay was noted in the healing of the CO2 laser wound. Both CO2 laser and scalpel wound expressed fibronectin, soon after wounding. The expression of fibronectin activities in the CO2 laser rose to the maximal level more slowly than the scalpel wound and its degree was weaker. CONCLUSION: Delayed expression in fibronectin may play a role in the delay of the CO2 laser wound healing.

Cytokine Gene Expression Associated with Bone Destruction in Cholesteatoma Tissues / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Cholesteatoma is composed of hyperproliferative keratinizing epithelium in the middle ear cavity. Although the mechanism of bone destruction by cholesteatoma has not been fully elucidated, it has been reported that activation of several cytokines followed by osteoclast activation might have a major effect on bone resorption in cholesteatoma. Among the several cytokines, it has been suggested that the overexpression of tumor necrosis factor-alpha (TNF-alpha), interleukin-1alpha (IL-1alpha) and interleukin-6 (IL-6) in the cholesteatomatous tissue is correlated with bone destruction, and transforming growth factor-beta1 (TGF-beta1) and interleukin-4 (IL-4) are associated with osteoclast inhibitory activity. To determine the potential role of several cytokines in the pathogenesis of cholesteatoma and its bone destruction, we investigated mRNA expression of four cytokines in the cholesteatomatous tissue. MAERIALS AND METHODS: We investigated mRNA expression of cytokines in 20 cholesteatomatous tissues as well as in the normal postaural skins using RT-PCR (reverse transcriptase-polymerase chain reaction). RESULTS: 1) Out of 20 cholesteatomatous tissues, six were mRNA expressions of IL-1alpha, four of IL-6, ten of TGF-beta1 mRNA, but no expressions of IL-4. There was no gene expression except six cases for TGF-beta1 in the normal postaural skin. 2) Three cases that expressed IL-1alpha, IL-6, and TGF-beta1 showed severe bone destruction, whereas no bone destruction was noted in 5 cases that expressed only TGF-beta1. 3) There was no significant correlation between the duration of disease and the individual cytokine expression. CONCLUSION: These findings suggest that IL-1alpha and IL-6 may play a major role in the proliferation and growth of cholesteatoma as well as the excitatory effect for bone destruction by cholesteatoma, and TGF-beta1 might have a protective effect for bone destruction.

Clinical Study with Objective Methods in Tinnitus Patients / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Tinnitus is the perception of a sound produced involuntarily inside the body. Tinnitus can be divided into two major categories: (1) tinnitus generated by para-auditory structure, usually from vascular or myoclonic sources: and (2) tinnitus generated by the sensorineural auditory system. With the recent advent of magnetic resonance imaging and auditory brain stem response, it is now possible to diagnose objectively the lesion as causes of intractable tinnitus while they are still quite rare. So, we can consider the surgical treatment on objective causes of tinnitus. MATERIALS AND METHODS: The authors analysed forty patients with tinnitus, who had visited the OPD of our ENT dept. from 1998 April to 1998 September, through history taking, physical examination, many objective auditory tests including auditory brain stem response (ABR) and MRI scan. RESULTS: In ABR test, conduction pathway of BAEP (Brain stem auditory evoked potential) was abnormal in 31 (59.6%) patients. Average latency of I-III, III-V and I-V were 2.29 msec, 1.92 msec and 4.22 msec. The 22 of 31 patients who had abnormal conduction pathway of BAEP showed hearing disturbance. Two patients showing normal conduction pathway of BAEP had hearing disturbance. In MRI scan, abnormal findings were observed only in 13 (25%) patients. CONCLUSION: The use of ABR and MRI to diagnose intractable tinnitus might be valuable in routine tests.