Toshiaki Tsukatani

Olfactory disturbance induced by deafferentation of serotonergic fibers in the olfactory bulb

The serotonergic neurons of the brain stem project widely throughout the central nervous system, and the olfactory bulb is one of the major forebrain targets of the ascending serotonin pathway. According to physiological studies, neurons of the olfactory bulb were found to reduce their spontaneous discharge rates by electrophoretically applied serotonin. However, roles of the bulbar serotonin in the sense of smell remain unanswered. In the present study, using 5,7-dihydroxytryptamine, a specific neurotoxin for serotonin, we found that the conditioned rats who learned to avoid a repellent by olfaction lost ability of discrimination by deafferentation of the bulbar serotonergic fibers. Such olfactory dysfunction did not occur in the early stage (three days after injection of the toxin) when the serotonergic fibers disappeared in the bulb, but developed a few weeks later. Interestingly, histological examination revealed marked shrinkage of the bulbar glomerulus which is a major termination site of the bulbopetal serotonergic fibers, and also a synaptic site of olfactory receptor cells and bulbar output neurons. The results indicate that depletion of the serotonergic fibers in the olfactory bulb causes glomerular atrophy and olfactory disturbance in the rat.

OK-432 therapy for a cervical thoracic duct cyst

Thoracic duct cysts are rare lesions presenting as mediastinal or supraclavicular masses. Approximately 20 cases have been reported in the literature, all of which were removed surgically and confirmed as cervical thoracic duct cysts by pathological findings. We report a patient diagnosed with a thoracic duct cyst by both imaging and biochemical findings who was treated without surgery using OK-432 (Picibanil; Chugai Pharmaceutical Co, Tokyo, Japan) sclerotherapy. A 35-year-old woman was referred to our hospital for evaluation of left supraclavicular swelling. She had no history of trauma or surgery to the region and no pain but reported slight pressure on swallowing. Physical examination revealed a firm and nontender mass of 12 6 cm in the left supraclavicular region. A CT and MRI revealed a thin-walled, nonenhancing cystic mass involving the left supraclavicular region and extending into the superior mediastinum (Fig 1A and B). The internal jugular vein and common carotid artery were located anteriorly to the mass. The possibility of a metastatic lesion from a head and neck or distant primary site was excluded by endoscopy, fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging, and hematological examination. Cyst aspiration was performed under ultrasonic guidance, and a light-pinkish milky fluid was removed. There was no evidence of infectious or malignant disease as determined by cytological and bacteriological examination of the fluid. Based on these findings, a cervical thoracic duct cyst was suspected. After consultation with the patient, OK-432 sclerotherapy was chosen over surgical excision for treatment of the cyst. Informed consent was obtained from the patient before the treatment. OK-432 therapy was performed under ultrasound guidance; the fluid (19 mL) inside the cyst was

Comparison of diagnostic findings using different olfactory test methods.

Objective: To quantify discrepancies in the diagnosis of olfactory function that might exist when comparing results obtained from centers using different methods of olfactory testing.

Odor Detection Ability and Thallium-201 Transport in the Olfactory Nerve of Traumatic Olfactory-Impaired Mice

Although olfactory nerve damage is a contributing factor in the diagnosis of posttraumatic olfactory loss, at present, there are no methods to directly assess injury to these nerves. We have shown that following olfactory nerve injury in mice, thallium-201 (201 Tl) transport from the nasal cavity to the olfactory bulb decreases. To determine if olfactory function after nerve injury could be assessed with nasal administration of 201 Tl, we measured the correlation between odor detection ability (ODA) and the rate of transport of 201 Tl in olfactory nerves. Both ODA and 201 Tl transport were measured after bilateral olfactory nerve transection for a 4-week period. Cycloheximide solution was used for ODA against tap water. 201 Tl transport was measured as the ratio of radioactivity in the nasal cavity and olfactory bulb with gamma spectrometry. There was a significant correlation between ODA and the rate of 201 Tl transport in the olfactory nerve. These findings suggest that olfactory function after nerve injury can be objectively evaluated with the nasal administration of 201 Tl.

Lipopolysaccharide-induced apoptosis of olfactory receptor neurons in rats.

Conclusion: Daily intranasal perfusion of lipopolysaccharide (LPS) for 14 days in rats induced apoptosis of olfactory receptor neurons (ORNs) over >3 but <7 days. Objectives: Smoking is one of the factors causing olfactory dysfunction. LPS is a major glycolipid component of the gram-negative bacterial cell wall and an active component of cigarette smoke. We studied whether LPS is one of the causes of tobacco-induced olfactory dysfunction by examining apoptosis in the olfactory epithelium after local exposure to LPS. Materials and methods: Rats received intranasal instillation of LPS or saline. Histochemical changes in the olfactory epithelium were examined using antibodies against single-stranded DNA, Bcl-2, Bax, and Caspase-3. We used different concentrations of LPS to examine the dose dependency and observed changes in the olfactory epithelium for a week after exposure cessation to see the duration of the effect of smoking. Results: We found that numbers of cells positive for ssDNA, Bcl-2, Bax, and Caspase-3 were increased on the exposed side. The number of ssDNA-positive cells reached a maximum on the first day and decreased to normal levels on the seventh day after cessation of exposure.

Bulbar Morphology and Expression of Bulbar Dopamine and Parvalbumin in Experimentally-induced Anosmic Rats

Morphological study was carried out in rats with olfactory dysfunction induced by deafferentation of serotonergic fibers in the olfactory bulb. With a computer capable of area measurements, olfactory bulbs of the anosmic rats were found to be decreased in size to 61% of control bulbs, and all bulbar layers were involved in the bulbar shrinkage. Given areas of each bulbar layer in control bulbs to be 100%, percentages of each bulbar layer in the anosmic rats were 23% in the olfactory nerve layer, 54% in the glomerular layer, 63% in the external plexiform layer, 83% in the internal plexiform layer and 81% in the granule cell layer. Dopamine-and parvalbumin-containing neurons were examined immunohistochemically in the experimentally-induced anosmic rats. As a result, immunoreactive neurons for these two chemical substances were significantly decreased in number (dopamine, 33% of control value; parvalbumin, 46% of control value). The present study, using an animal model of anosmia, provided quantitative data on the bulbar atrophy and showed effects of anosmia on expression of dopamine and parvalbumin in the bulb.

Schizophyllum commune-induced allergic fungal rhinosinusitis and sinobronchial mycosis.

We present 32- and 38-year-old males with Schizophyllum commune-induced allergic fungal rhinosinusitis (AFRS). S. commune-induced AFRS was diagnosed by clinical and radiographic findings, positive specific IgE antibodies against S. commune as measured by the ImmunoCAP system, and sequencing analysis of the fungus. Our two cases with S. commune-induced AFRS for the first time showed evidence for type 1 hypersensitivity to S. commune as determined by using specific IgE antibodies against S. commune, and the fungus was identified by sequence analysis.

Expression and Localization of the Cell Adhesion Molecule SgIGSF during Regeneration of the Olfactory Epithelium in Mice

Spermatogenic immunoglobulin superfamily (SgIGSF) is a cell adhesion molecule originally discovered in mouse testis. SgIGSF is expressed not only in spermatogenic cells but also in lung and liver epithelial cells and in neurons and glia of the central and peripheral nervous systems. In the present study, we examined the expression and localization of SgIGSF in mouse olfactory epithelium before and after transection of the olfactory nerves, by RT-PCR, Western blotting and immunohistochemistry. In normal olfactory mucosa, SgIGSF showed 100 kDa in molecular weight, which was identical with that in the lung but different from that in the brain. SgIGSF was expressed on the membrane of all olfactory, sustentacular and basal cells, but more abundantly in the apical portions of the olfactory epithelium where the dendrites of olfactory cells are in contact with sustentacular cells. After olfactory nerve transection, mature olfactory cells disappeared in 4 days but were regenerated around 7–15 days by proliferation and differentiation of basal cells into mature olfactory cells through the step of immature olfactory cells. During this period, both the mRNA and protein for SgIGSF showed a transient increase, with peak levels at 7 days and 11 days, respectively, after the transection. Immunohistochemistry showed that the enriched immunoreactivity for SgIGSF at 7–11 days was localized primarily to the membrane of immature olfactory cells. These results suggested that, during regeneration of the olfactory epithelium, the adhesion molecule SgIGSF plays physiological roles in differentiation, migration, and maturation of immature olfactory cells.

Laparoscopically harvested omental flap for head and neck reconstruction.

INTRODUCTION The omentum is a highly vascularized tissue that resists infection and adapts well to an ischemic environment attributable to previous irradiation. Because laparotomy was required, the use of the greater omentum flap used to be regarded as a backup option in complicated cases. Today, the free omentum is commonly used to improve subcutaneous contour and for wound coverage by providing a vascularized recipient bed for skin grafts. Saltz et al. were the first to report laparoscopic harvesting of the omentum in 1993, followed by Kamei et al., who reported an improved method with a smaller abdominal incision in 1998. Because laparoscopic surgery is a technique commonly used by surgeons specializing in alimentary tracts, laparoscopic harvesting of the omentum is not difficult with their help. This easy availability of the omentum may result in changing the free omentum flap from a backup option to a first-choice flap. We report a method for laparoscopic harvesting and trimming of the omentum. This method is based on its vascular anatomy, and proper trimming of the harvested omentum is essential for a good fit for a particular head and neck soft tissue defect.

Usefulness of curry odorant of odor stick identification test for Japanese in olfactory impairment screening.

Conclusion: The curry odorant of the odor stick identification test for Japanese (OSIT-J) is useful in screening for olfactory impairment in Japanese subjects. Objective: The present study was designed to determine the most useful odorant of the OSIT-J in screening for olfactory impairment in Japanese subjects. Subjects and methods: We studied olfactory impairment screening with the OSIT-J in 83 participants (49 male, 34 female; average age 50 years) in an executive check-up at NTT West Kanazawa Hospital. Olfactory discrimination acuity was evaluated with three odorants of the OSIT-J (rose, curry, and sweaty-smelling clothes), each known to be significantly correlated with the assessment of the Japanese standard olfaction test (T&T olfactometer). Those participants who did not score full marks in tests with the three odors were assessed with another nine odorants of the OSIT-J. Results: The positive predictive value was 100% in the screening with the curry odorant. In 38 participants who did not identify all three odors correctly, the identification of the curry odor was significantly correlated with the scores for all 12 odors (p <0.005). Identification of the curry odor was not significantly correlated with identification of the menthol odor of OSIT-J.