Takao Hamamoto

Localization of transient receptor potential vanilloid (TRPV) in the human larynx

Conclusion. Transient receptor potential vanilloid (TRPV) 1, 2, 3, and 4 were expressed in the human larynx, which may act as laryngeal nociceptors perceiving luminal noxious stimuli, play an important role in thermal sensation and osmotic sensation, and are also related to some pathological conditions and prevention of aspiration. Objective. Expression of TRPV1, 2, 3, and 4 in the human larynx was analyzed. Materials and methods. Specimens of human epiglottic epithelium obtained from six patients were used in this study. The localization of TRPV1, 2, 3, and 4 in the laryngeal epithelium was investigated by immunohistochemistry. Results. Immunohistochemical study revealed the presence of TRPV1, 2, 3, and 4 in the laryngeal epithelial cells. Chemoradiotherapy may reduce the expression of TRPV1, 2, 3, and 4, which might be a result of the mucositis and neuropathy in laryngeal epithelium.

Age-dependent changes in the expression of klotho protein, TRPV5 and TRPV6 in mouse inner ear

Conclusions. klotho protein content decreases with increasing age, which weakens resistance to oxidative stress, resulting in induced cell death as well as modulating endolymph fluid homeostasis. Down-regulation of klotho also leads to down-regulation of TRPV5 and TRPV6, resulting in modified Ca2 + homeostasis in the inner ear, dysfunction of sensory cell transduction and causing hearing loss and/or vestibular disorders. Objective. Expression of klotho, TRPV5 and TRPV6 in the mouse inner ear and age-related changes were analysed. Materials and methods. CBA/J mice aged 8 weeks and 24 months were used in this study. The localization of klotho, TRPV5 and TRPV6 in the inner ear of young and old mice was investigated by immunohistochemistry. Results. Immunostaining for klotho was observed in stria vascularis, outer and inner hair cells (OHCs and IHCs), and in vestibular sensory cells and dark cells, and less intensely in the spiral and vestibular ganglion cells. Expression of TRPV5 was found in stria vascularis, organ of Corti, vestibular sensory cells and dark cells, and less intensely in the spiral and vestibular ganglion cells. Expression of TRPV6 was found in supporting cells of the organ of Corti, with weak labelling in OHCs and IHCs. Weak fluorescence was also noted in stria vascularis, and faint fluorescence in the spiral ligament. Vestibular sensory and dark cells as well as vestibular ganglion cells showed weak fluorescence. In the old animals, the expression patterns of klotho, TRPV5 and TRPV6 were identical with those in young animals, although fluorescence intensity was significantly weaker.

Localization of transient receptor potential channel vanilloid subfamilies in the mouse larynx

Conclusion. Laryngeal epithelium contains TRPV1, 2, 3 and 4, which may act as laryngeal nociceptors perceiving luminal noxious stimuli, play an important role in thermal sensation, osmotic sensation, and are also related to pathological conditions, such as inflammatory response, genesis of cough, asthma. Objective. Expression of TRPV1, 2, 3 and 4 in the normal CBA/J mouse larynx was analysed. Materials and methods. CBA/J mice were used in this study. The localizations of TRPV1, 2, 3 and 4 in the laryngeal epithelium were investigated by immunohistochemistry. Results. Immunohistochemical study revealed the presence of TRPV1, 2, 3 and 4 in the laryngeal epithelial cells. TRPV1 and TRPV2 were often co-localized with substance P, while the co-localization of substance P and TRPV3 was rare and TRPV4 was not co-localized with substance P.

Expression of transient receptor potential channel melastin (TRPM) 1–8 and TRPA1 (ankyrin) in mouse inner ear

Conclusions: It has been shown that TRPMs may play a functional role in sensory cell physiology, fluid homeostasis, sensory cell death, and thermosensation in the inner ear, while TRPA1 plays an important role in sensory transduction. Objective: To study expression of TRPM1–8 and TRPA1 in the mouse inner ear. Materials and methods: The localization of TRPM1–8 and TRPA1 in the inner ear of normal and gentamicin-treated CBA/J mice was investigated by immunohistochemistry. Results: The stria vascularis displayed a positive immunofluorescent reaction to TRPM1, 2, 3, 6, and 7. In the organ of Corti, outer and inner hair cells (OHCs and IHCs) showed positive immunofluorescence to TRPM1, 2, 3, 6, 7, and 8. Spiral ganglion cells were immunoreactive to TRPM1, 2, 3, 6, 7, and 8. The nerve fibers in the spiral ganglion cells and the nerves innervating the OHCs or IHCs were noticeably immunofluorescent to TRPM8 and TRPA1. In the vestibular end organs, vestibular sensory cells showed immunofluorescence to TRPM1, 2, 3, 6, and 7. The vestibular dark cells showed immunofluorescence to TRPM1, 3, 6, and 7; only the apical portion reacted to TRPM4. The nerve fibers innervating the vestibular sensory cells were distinctly reactive to TRPM8 and TRPA1, while the vestibular ganglion cells reacted to TRPM1, 2, 3, 6, 7, and 8.

Management of Intractable Nasal Hyperreactivity by Selective Resection of Posterior Nasal Nerve Branches

The posterior nasal nerves emerge from the sphenopalatine foramen and contain sensory and autonomic nerve components. Posterior nasal neurectomy is an effective method to remove pathological neural networks surrounding the inferior turbinate that cause unregulated nasal hypersensitivity with excess secretion in patients with severe allergic rhinitis (AR). We describe the sophisticated endoscopic surgical procedure that allows feasible access to the confined area and selective resection of the nerve branches with the preservation of the sphenopalatine artery (SPA). We retrospectively analyzed the cases of 23 symptomatic severe AR patients who failed to respond to standard medical treatment and underwent surgery. There have been no major complications after surgery including nasal bleeding or transient numbness of the upper teeth. The mean total nasal symptom scores (TNSS) were decreased by 70.2% at 12 months after the procedure. Our comparison of the clinical effectiveness based on the number of severed nerve branches revealed that the improvement of the TNSS was significantly higher in patients with >2 branches. We conclude that this minimally invasive technique that preserves the SPA is clinically useful and decreases the rate of postoperative complications. This trial is registered with UMIN000029025.

Low-dose dexamethasone with fosaprepitant and palonosetron to prevent cisplatin-induced nausea and vomiting in head and neck cancer patients

Abstract Objective: To determine if a lower dose of dexamethasone can be used in combination with fosaprepitant and palonosetron for cisplatin-induced nausea and vomiting in head and neck cancer patients, we conducted a single-center, two-arm, cross-over comparison study. Methods: Patients were randomly assigned to either standard dose dexamethasone group: intravenous 9.9 mg on day 1 and 6.6 mg on days 2–4 or low-dose dexamethasone group: intravenous 3.3 mg on days 1–4 for the first course and crossed over to the other treatment for the second course. The primary endpoint was complete response (CR) in the overall period. Results: Twenty-five patients were screened for the study and 22 were evaluable. Eleven patients were randomly assigned to the standard dose dexamethasone group and 12 patients to the low-dose dexamethasone group. The CR rate in the overall period was 86% in the standard dose group and 73% in the low-dose group, showing no significant difference (p = .61). Conclusion: The efficacy of low-dose dexamethasone with fosaprepitant and palonosetron was not inferior to that of the standard dose dexamethasone in the highly emetogenic cisplatin-based treatment for head and neck cancer patients.

Extraskeletal osteosarcoma in the parotid gland: A case report

Extraskeletal osteosarcoma is a very rare tumor and accounts for 4-5% of all osteosarcomas. We describe a 47-year-old Japanese man who presented with a right parotid tumor. The patient underwent total resection with postoperative radiotherapy; however, the tumor recurred in the lung, whereupon he underwent chemotherapy and partial lung resection. After surgery, a hemorrhagic brain metastasis appeared; this tumor was extirpated to prevent bleeding into the brain, after which additional chemotherapy was administered. Nevertheless, the patient developed additional metastases and died 17 months after the total parotidectomy. This tumor was unique in that it arose in the parotid gland; this case provides an instructional example of an extremely rare manifestation of this type of tumor.