Muneo Nakaya

Immunohistochemical Localization of Histamine Receptor Subtypes in Human Inferior Turbinates

Histamine is an important chemical mediator in allergic rhinitis and plays an important role in eliciting the nasal symptoms of the disorder. However, the immunohistochemical localization of histamine receptor subtypes (H1R, H2R, H3R, and H4R) in human nasal mucosa is unknown. There are also no prior studies of H3R and H4R in human nasal mucosa. The objective of this study was to examine the distribution of histamine receptor subtypes in the human inferior turbinates by an immunohistochemical method. H1R was localized primarily in the epithelium, vessels, and nerves. H2R was localized primarily in the epithelium and the glands. H3R and H4R were clearly distributed on the nerves. In addition, H1R, H3R, and H4R were clearly localized on the same nerves. This result indicates that H1R, H3R, and H4R adjoin and regulate each other in the same nerves. All histamine receptor subtypes may play some role in patients with allergic rhinitis.

Immunohistochemical Localization of Subtypes of Muscarinic Receptors in Human Inferior Turbinate Mucosa

The regulation of glandular secretions and vasomotor tone in human nasal mucosa implicates muscarinic receptors. There are 5 recognized classes (m1 through m5) of muscarinic receptor subtypes, and the aim of our study was to localize muscarinic receptor subtypes (m1 through m5) in human inferior turbinate mucosa by an immunohistochemical method. We found m1 and m2 receptors distributed on glands, arteries, veins, and epithelia; m4 receptors were found around arteries; and m5 receptors were identified on glands and arteries. We found m3 receptors to be the most extensively distributed on glands, arteries, and veins of all of the muscarinic receptor subtypes. The m3 receptor is probably important in the physiology of the human inferior turbinate. This study may help identify the best target for more selective muscarinic drugs and guide the treatment of allergic and nonallergic rhinitis.

Noninvasive system for evaluating allergen-induced nasal hypersensitivity in murine allergic rhinitis

Until now there has been no method for physiologically evaluating nasal hypersensitivity in mice. Enhanced pause (Penh) has been used as an indicator that reflects changes in the lower airway. Recently, however, there is disagreement regarding the significance of the Penh system; this is because Penh is not essentially a physiological parameter, and it might not necessarily represent a change in the lower respiratory tract. The purpose of the present study is to investigate whether Penh could be applicable for analyzing nasal hypersensitivity in mice. BALB/c mice were sensitized with ovalbumin (OVA) through a combination of intraperitoneal injection and daily intranasal challenge in an awake condition. Penh was measured at each time point during sensitization, or a serial change in Penh value was followed after the final nasal challenge and the effect of treatment was assessed. Following sensitization and nasal challenge, the Penh value gradually increased and showed a significant difference on day 14. Changes in IgE, eosinophil infiltration into nasal mucosa, and OVA-induced symptoms all strongly correlated with the increase in Penh. On day 19, after OVA nasal provocation, Penh gradually increased and reached maximal values 25 min after the challenge. Pretreatment with dexamethasone or a histamine H1 blocker significantly suppressed this increase in Penh. We confirmed that intranasal OVA challenge did not induce bronchoconstriction by measuring airway resistance and bronchoalveolar lavage fluid, and through histological examination. These results clearly demonstrate that Penh could be a useful noninvasive indicator for studying nasal hypersensitivity.

Prolonged allergen challenge in murine nasal allergic rhinitis : Nasal airway remodeling and adaptation of nasal airway responsiveness

Background: Nasal airway remodeling exists in allergic rhinitis, but it appears to be far less extensive than in asthma. However, there has been little study about nasal airway remodeling and no study using mice models. It has been reported that airway hyperresponsiveness decreased after prolonged allergen challenge in a chronic murine asthma model together with the progression of remodeling. However, there has been no study of the relation of remodeling and airway responsiveness in nasal allergy. Therefore, we have undertaken this investigation to characterize nasal airway structural changes after prolonged allergen challenge and to examine the relationship between nasal airway hyperresponsivity and remodeling.

Schwannoma of the trachea; a new resection technique

Tumors of the trachea are rare, especially schwannoma. We diagnosed a 27-year-old man with schwannoma of the trachea after he was admitted to our hospital with complaints of progressive dyspnea and wheezing. He was treated as having bronchial asthma initially, but his signs and symptoms did not improve with conventional therapy. Flexible fiberscopy revealed the presence of a submucosal tumor in the subglottic area. Tracheal tomography, computed tomography (CT) and magnetic resonance imaging (MRI) revealed the presence of a mass in the trachea that extended from the cricoid cartilage level to the second tracheal ring. After tracheostomy, we removed the tumor from a tracheostoma upwards to the larynx without a laryngofissure, using forceps and scissors usually used for laryngomicrosurgery and endoscopes usually used for sinus surgery. No complications developed during or after the procedure. To our knowledge, this is the first report of the removal of a tracheal schwannoma by this technique.

Nasal allergic response mediated by histamine H3 receptors in murine allergic rhinitis

Background: Histamine is one of the most important chemical mediators causing nasal allergic symptoms, and H1 receptor antagonist have been used as the treatment first choice in nasal allergy. The presence of H3 receptors has also been determined in the human nasal mucosa, but few studies have investigated the involvement of H3 receptors in nasal allergy.

Laryngotracheal separation procedure for elderly patients

A procedure for laryngotracheal separation was performed on 5 elderly patients in poor general condition to prevent habitual aspiration pneumonia. Intractable aspiration was relieved in all the patients with no major postoperative complications. In this intervention, a modification of the procedure previously reported, the anterior part of the tracheal and cricoid cartilage was removed, and the subglottic mucosa was sutured to fashion a blind pouch. This procedure could be adjusted even in cases of severe laryngoptosis or after high tracheostomy. Laryngotracheal separation is likely to be useful as a simple and safe procedure even for older patients. If this comes to be, it will serve as a valuable intervention in todays aging society.

Immunohistochemical study of m1-m5 muscarinic receptors and nNOS in human inferior turbinate mucosa.

Conclusion. This study suggested that nitric oxide (NO) takes part in the parasympathetic nerve control functions mainly through m3 receptors and subsequently through m1 receptors. Objectives. The regulation of glandular secretions and vasomotor tone in human nasal mucosa implicates muscarinic receptors. There are five recognized classes (m1–m5) of muscarinic receptor subtypes. NO is a free radical gas that has been found to be produced in neuronal cells by the action of enzyme neural nitric oxide synthase (nNOS). The aim of this study was to identify the colocalization of muscarinic receptor subtypes (m1–m5) and nNOS in the human inferior turbinate mucosa. Materials and methods. Human inferior turbinate mucosa was stained by using the antibody of muscarine receptor subtypes and nNOS in an immunohistochemical double-staining method. Results. The colocalization of m3 receptors and nNOS-immunoreactive nerve fibers was most extensively distributed on glands, vessels, and epithelium in all muscarinic receptor subtypes. These findings lead us to propose that NO also acts as a neurotransmitter in glands, vessels, and epithelium of the human nasal mucosa and can be assigned to parasympathetic nerve structures through m3 receptors mainly and m1 receptors subsequently.

Endoscopic transoral and transmaxillary excision of the infratemporal fossa hemangioma

Hemangiomas in the infratemporal fossa (ITF) are extremely rare benign vascular tumors. For many tumors of the ITF, with the exception of some small hemangiomas, a lateral facial approach has often been required. Recently, however, there have been some reports that minimally invasive endoscopic surgery can be used in the ITF; this would reduce the risk of surgical complications. To date, there has been no report of a hemangioma of the ITF exceeding 6 cm being resected by the endoscopic approach without facial incisions. Here, however, we report two cases of ITF hemangiomas that were completely extracted endoscopically, using a transmaxillary and transoral approach, without facial incisions or surgical complications.

A clinical review of 38 cases of cervical tuberculous lymphadenitis in Japan - The role of neck dissection.

OBJECTIVES After tuberculous pleurisy, lymphadenitis arising from cervical lesion is the second most common form of extrapulmonary tuberculosis. It is generally treated with antituberculosis agents, but some patients resist chemotherapy. In such cases, surgical resection is often considered as an alternative treatment. This study aims to evaluate the therapeutic outcome of cervical tuberculous lymphadenitis and the future course of treatment of this disease. METHODS We retrospectively reviewed the clinical charts of patients diagnosed at the Tokyo Metropolitan Tama Medical Center between 2009 and 2015 and identified 38 cases of cervical tuberculous lymphadenitis. Precisely 798 patients were registered for primary tuberculosis at our institution during the same period. RESULTS Patient ages ranged from 21 to 85 years (average: 58.9 years), and the male-to-female ratio was 1:1.2. The range of tuberculosis progression was as follows: 30 (78.9%) in only the cervical lymph node, 3 in the other (axillary, mediastinal, and abdominal) lymph nodes, 1 in the lung and vertebrae lumbales, 2 in the lung, and 1 in the pleural membrane. All 38 patients were initially treated with antituberculous drugs at the Department of Pulmonary Medicine based on guidelines for tuberculosis cases in Japan. In seven cases, the antituberculous drugs were replaced due to side effects. Four cases involved a single drug-resistant strain, and one case involved a double drug-resistant strain. Thirty-three (86.8%) cases were cured by chemotherapy alone. The three patients resistant to chemotherapy were successfully treated through neck dissection. Thirty-six cases (94.7%) were cured by chemotherapy or chemotherapy and surgery. CONCLUSION Local therapy could prove effective in cervical tuberculous lymphadenitis patients who exhibit an inadequate response to drugs. The role of neck dissection in cervical tuberculous lymphadenitis remains an important consideration.