Yasushi Ohta

Surgical management of the plunging ranula : a review of seven cases

We have treated seven patients with a plunging ranula during the past 10 years. All patients underwent surgery via a cervical approach. In two, the ranula reached the anterior neck by passing through a dehiscence in the mylohyoid muscle, while in the other five the plunging ranula passed posteriorly to the mylohyoid muscle. A pseudocyst was extirpated in each patient. Although total sublingual gland excision was not performed in two patients, no recurrence was observed in any patient. Incision of the pseudocyst facilitated subsequent procedures and decreased the incidence of transient facial paralysis. In the presence of a cervical mass without swelling of the oral floor, a cervical approach may still be the method of choice either for the first operation or for salvage surgery after recurrence subsequent to intraoral procedures. It is based on the fact that there may be ectopic sublingual glands residing on the inferior surface of the mylohyoid muscle.

Proliferation markers, proliferating cell nuclear antigen, Ki67, 5-bromo-2'-deoxyuridine, and cyclin D1 in mouse olfactory epithelium

We immunohistochemically identified proliferating cells in the olfactory epithelium of mice, using an anti–proliferating cell nuclear antigen (PCNA) antibody, an anti-Ki67 antibody, an anti–5-bromo-2′-deoxyuridine (BrdU) antibody, and an anti–cyclin D1 antibody. Positive cells stained by the 4 antibodies were identified mainly in the basal layer. The mean numbers of positive cells stained by the 4 antibodies in 500 olfactory epithelium cells from each animal were as follows: PCNA-positive cells 42, Ki67-positive cells 23, BrdU-positive cells 13.7, and cyclin D1–positive cells 9.2. PCNA may be detected in both proliferating and resting cells. Ki67 is an intranuclear antigen expressed in proliferating, but not resting, cells. Anti-BrdU antibodies might stain proliferating cells only following the S-phase, but not the G1-phase. Cyclin D1 is a protein that works during the G1-phase of the cell cycle. When we stain proliferating cells using proliferating cell markers, it is important to consider the cell cycle phases during which each marker stains.

Evaluation of recurrent nerve paralysis due to thoracic aortic aneurysm and aneurysm repair

Objectives: We sought to clarify the relationship between the outcome of recurrent laryngeal nerve paralysis with the characteristics of the thoracic aortic aneurysm and the surgical procedure used in each patient.

Eosinophilic inflammation in the middle ear induces deterioration of bone-conduction hearing level in patients with eosinophilic otitis media.

Objective: Eosinophilic otitis media (EOM) is characterized by the extensive accumulation of eosinophils in the middle ear mucosa and middle ear effusion and is usually associated with bronchial asthma. Eosinophilic otitis media patients show gradual or sudden deterioration of hearing. In our previous study, we reported that high-tone loss was more frequently found and more severe in EOM patients than in control patients with chronic otitis media. These findings suggest that not only bacterial infection but also eosinophilic inflammation in the middle ear may damage the inner ear. The present study was performed to determine whether eosinophilic inflammation is indeed related to deterioration of bone-conduction hearing level (BCHL). Patients: Fifty-five ears of 28 patients with EOM associated with bronchial asthma were included in this study. Middle ear effusion (MEE) samples were collected from all the patients, and the concentrations of eosinophilic cationic protein (ECP) and immunoglobulin E (IgE) were measured by fluorescence enzyme immunoassay. The BCHLs at 2 and 4 kHz for the worse-hearing ear of each patient were correlated with the concentrations of ECP and IgE. Results: The concentration of IgE in MEE significantly and positively correlated with BCHL at 2 and 4 kHz. The ears with a higher concentration of ECP in MEE also tended to show deterioration of BCHL at 4 kHz. Other clinical risk factors for BCHL deterioration were male sex, long duration of EOM, association with bacterial infection, severe inflammatory changes of the middle ear mucosa, and high serum IgE concentration. Conclusion: Eosinophilic-inflammation-related substances such as ECP and IgE are closely related to the deterioration of BCHL at high frequencies. Particularly, IgE concentration in MEE is a good indicator of BCHL elevation. We should always pay attention to the hearing acuity of EOM patients with the risk factors.

Laryngeal Adjustment in Whispering Magnetic Resonance Imaging Study

Previous studies confirmed that during whispering the glottis is kept open to prevent vocal fold vibration and the supraglottal structures are constricted. However, there has been no study exploring the exact contour of the laryngeal lumen in the frontal dimension during the production of whispering. In order to further elucidate the nature of the laryngeal adjustments regarding the contour of the laryngeal lumen in whispering, and the role of supraglottal constriction in particular, we conducted a physiological study using magnetic resonance imaging. According to the results, the supraglottal structures were not only constricted but also shifted downward, attaching to the vocal fold to prevent vocal fold vibration completely during whispering. The results suggested the underlying mechanism of suppression of vocal fold vibration during the production of whispering.

Bone conduction hearing level in patients with eosinophilic otitis media associated with bronchial asthma.

Objective: Eosinophilic otitis media (EOM) is characterized by the extensive accumulation of eosinophils in the middle ear mucosa and middle ear effusion and is usually associated with bronchial asthma. EOM patients show gradual deterioration of hearing and sometimes become deaf suddenly. However, there have been no systemic studies of bone conduction hearing level (BCHL) of patients with EOM. Patients: Seventy-one ears of 38 patients with EOM associated with bronchial asthma were included in this study. For controls, 65 ears of age-matched 60 patients with chronic otitis media (COM), who underwent tympanoplasty, were similarly studied. The BCHLs at 250, 500, 1,000, 2,000 and 4,000 Hz of EOM patients were compared with those of COM patients, and the clinical risk factors for the deterioration of BCHL in EOM were analyzed. Results: Two patients became profoundly deaf unilaterally after the onset of EOM. High-tone loss was more frequently found and more severe in EOM patients than in COM patients. The clinical risk factors for high-tone loss were older age, male sex, presence of pathogens, and condition of the middle ear mucosa. Conclusion: High-tone hearing loss and profound hearing loss were frequently associated with EOM, suggesting that inflammatory products of the middle ear invade the inner ear via the round window to cause inner ear damage. To prevent the deterioration of BCHL, the control of eosinophilic inflammation and bacterial infection is mandatory.

Expression of NeuroD and TrKB in developing and aged mouse olfactory epithelium

To better understand the roles of NeuroD, a member of the basic helix-loop-helix transcription factor family, during the differentiation of olfactory receptor neurons, we studied the expression of NeuroD in developing and aging mouse olfactory epithelium (OE). During embryonic period, NeuroD expression is confined in the basal compartment of OE. During neonatal period, NeuroD expression is detected in the middle compartment and in the basal compartment of OE. In the adult, the number of NeuroD expressing cells in the basal compartment significantly decreased, while the NeuroD- positive cells in the middle compartment was maintained throughout lifetime. This dual phase expression pattern of NeuroD suggests multiple roles of NeuroD in the neurogenesis of ORNs.

Immunohistochemical localization of proliferating cells and epidermal growth factor receptors in mouse olfactory epithelium.

We investigated age-related changes in proliferating cells and epidermal growth factor receptors (EGFRs) in mouse olfactory epithelium using an immunohistochemical method with the antiproliferating cell nuclear antigen (PCNA) antibody and the antihuman EGFRs antibody. Many PCNA-positive cells occurred in the surface and basal layers of the olfactory epithelium in the embryonal and neonatal mice. However, only some PCNA-positive cells occurred in the basal layer of adult mice, and only a few presented in the basal layer of aged mice. EGFRs were observed in all layers of the olfactory epithelium at the embryonal and neonatal stages, but were not identified in the olfactory epithelium at the adult or aged stages. We believe that a decrease in EGFRs in the olfactory epithelium induces the inhibition of cell proliferation, with the resultant atrophy of the olfactory epithelium.

Stroboscopic Observation of the Larynx After Radiation in Patients with T1 Glottic Carcinoma

We studied laryngeal video stroboscopy (LVS) system for evaluation of patients with glottic carcinoma (T1N0M0) before and after radiotherapy. There were 10 patients with T1 glottic squamous cell carcinoma (9 men and 1 woman) who received radiotherapy at the Hitachi General Hospital. We performed LVS before and after radiotherapy. The presence or absence of mucosal waves (MW) was particularly noted. No MW were present before radiotherapy but at 1-6 months after, MW gradually appeared. One year after radiotherapy all patients showed MW on LVS. In patients with glottic carcinoma MW recovered after radiation therapy. LVS may be useful for the clinical follow-up of post-radiation patients for early detection of recurrence of glottic carcinoma.

Changes in epidermal growth factor receptors in olfactory epithelium associated with aging.

To clarify the mechanisms of age-related changes in the olfactory epithelium, we investigated age-related changes in epidermal growth factor receptors (EGFRs) in the epithelium. We examined 3 mice at each of the following stages: embryonal (embryonic days 14 and 16), neonatal (postnatal days 1 and 7), adult (postnatal weeks 5 and 12), and aged (postnatal years 1.5 to 2). The olfactory epithelium of each mouse was stained with sheep anti-human EGFR polyclonal IgG by an immunohistochemical method. The EGFRs were observed in all layers of the olfactory epithelium at the embryonal and neonatal stages. They were identified only in the basal layer of the olfactory epithelium at adult and aged stages, and the number of regions in which EGFRs were identified in the basal layer of the olfactory epithelium decreased in aged mice compared to adult mice. We believe that a decrease in EGFRs in the olfactory epithelium induces the inhibition of cell proliferation, with resultant atrophy of the olfactory epithelium.