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Naonobu Takeuchi

Publications and source records attributed to Naonobu Takeuchi.

8 recordsLinked to original sources
PubMed2006

Age-related changes in cell density and the proliferation rate of olfactory ensheathing cells in the lamina propria of postnatal mouse olfactory mucosa.

We investigated age-related changes in the distribution and proliferation of olfactory ensheathing cells (OECs) in postnatal mouse olfactory mucosa. In contrast to reported data on other glial cell types in the peripheral and central nervous systems, OEC cell density in the olfactory nerve bundles in the lamina propria remained almost constant from 10 days through 16 months of age. Electron microscopy of the nerve bundles revealed that axon packing density also was constant during that period. These findings suggest that the ratio of the number of OECs to the unit length of the olfactory neuron axons ensheathed by them does not change markedly throughout the lifetime of mice in an undisturbed condition. By contrast, OEC proliferative density decreased rapidly in the 10-day to 1-month-old period, showing a significant difference, and for the rest of life remained at low level, similar to previous values reported for other glial cell types.

Aging↗
PubMed2006

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.

Airway Resistance↗
PubMed2006

Evaluation of recovery from transient facial palsy following canalplasty and tympanoplasty for the treatment of congenital aural atresia.

OBJECTIVES: Canalplasty is a surgical procedure of the external auditory canal. In this study we examined anatomic risk factors for facial nerve injury in aural atresia surgery, in addition to facial nerve outcomes and the time course of recovery in patients with facial nerve palsy following atresia surgery. METHODS: Transient facial palsy was observed immediately after surgery in 6 of 99 ears (6 of 87 patients) after canalplasty and tympanoplasty for the treatment of congenital aural atresia. We assessed the course of recovery and mean scores using Jahrsdoerfer's grading system. RESULTS: The rate of absence of the stapes and the rate of presence of positional anomalies of the facial nerve were significantly higher among cases with facial palsy, and Jahrsdoerfer total scores were significantly lower among cases with facial palsy. The mean recovery time in 5 cases with a minimum electroneurography value of 0% was 16.2 weeks (range, 14 to 18 weeks). No trends during recovery were detected for the nerve excitability test and R1 components of the blink reflex. CONCLUSIONS: The anatomic conditions that cause a predisposition to transient facial palsy include absence of the stapes and the presence of positional anomalies of the facial nerve. Although some patients displayed transient facial palsy after surgery, all patients fully recovered. Mechanisms of facial nerve injury are proposed.

Adolescent↗
PubMed2005

A case of Mobius syndrome--radiological and electrophysiological findings.

Mobius syndrome is characterized by congenital bilateral facial palsy and abducens nerve paralysis, but reports of radiological and electrophysiological findings are scarce. A 4-year-old boy presented with mask-like facies noted at birth after a 34-week pregnancy. Examination revealed bilateral facial and abducens nerve paralysis with no other neurological abnormalities. Computed tomography revealed bilateral absence of facial nerve canal in the middle ear. Brain magnetic resonance imaging indicated a narrow than expected nerve in the internal auditory canal (IAC). Evoked electromyography and blink reflex testing to evaluate facial nerve function yielded no responses bilaterally. Facial palsy thus appears to be caused by facial nerve dysplasia or aplasia.

Blinking↗
PubMed2005

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. OBJECTIVE: We used a murine allergic model to investigate the presence of nasal mucosa H3 receptor mRNA and any H3 receptor agonist or antagonist influences on clinical nasal allergic symptoms. METHODS: H3 receptor mRNA in nasal mucosa was investigated by reverse-transcription polymerase chain reaction. OVA-sensitized mice were given an intraperitoneal injection of H3 receptor agonist or antagonist, and clinical nasal allergic symptoms were scored over 10 minutes after nasal provocation of OVA. Inhibition of nasal allergic symptoms was also examined using an H1 receptor antagonist alone and using a both an H3 receptor agonist and an H1 receptor antagonist. RESULTS: H3 receptor mRNA was identified in the murine nasal mucosa. The H3 receptor agonist (R)-alpha-metylhistamine significantly inhibited clinical nasal allergic symptoms of OVA-sensitized mice. The H3 receptor agonist and H1 receptor antagonist inhibited clinical nasal allergic symptoms in the murine allergic model more strongly than the single drug. CONCLUSION: The foregoing results indicate that H3 receptors are involved in modulation of nasal allergy. H3 receptor agonists can also be useful as a novel therapeutic approach in nasal allergy. Both H3 receptor agonist and H1 receptor antagonist may be more effective than a single drug.

Allergens↗
PubMed2004

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.

Adult↗
PubMed2002

Objective evaluation of infraorbital nerve involvement in maxillary lesions by means of the blink reflex.

OBJECTIVE: To objectively evaluate the effects of maxillary lesions on the infraorbital nerve (ION). METHODS: We investigated the latencies (R1, R2) of the blink reflex, stimulating the infraorbital foramen electrically (18 mA, 0.2 millisecond). Twenty-two patients with unilateral maxillary lesions were enrolled. RESULTS: Ten patients showed delayed or absent R1 on the lesion side. Four of 20 patients showed delayed difference in R2 latency. Ten (77%) of 13 patients with lesions along the ION pathway showed an abnormal blink reflex. Only 3 patients demonstrated a normal blink reflex despite a lesion along the pathway of the ION. All patients whose ION pathway was intact showed a normal blink reflex. CONCLUSIONS: These results suggested that lesions along the ION pathway may impair the afferent pathway of the blink reflex. The blink reflex may be valuable to evaluate maxillary lesions objectively. Furthermore, R1 is more effective than R2 in detecting ION defects.

Adult↗