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Biomedical subjects

Toshiaki Yagi

Publications and source records attributed to Toshiaki Yagi.

34 records · Page 2Linked to original sources

Ultrasonographic demonstration of retropharyngeal lymph nodes: preliminary report.

The aim of this study was to describe the results of ultrasonography of upper retropharyngeal lymph node (RPN) metastasis in patients with pharyngeal carcinomas. A total of 10 patients with metastatic RPN were examined using percutaneous ultrasound (US) with 3.5-MHz probes. Primary cancer sites were the nasopharynx in two patients, the oropharynx in three and the hypopharynx in five. Metastatic RPNs lay in the level of occipital bone in five patients, C1 in nine, and C2 in five. US images were compared with previously obtained computerized tomography (CT) images based on size and depth. In all of the 10 patients, metastatic RPNs were ultrasonographically demonstrated as hypoechoic masses. Nodal sizes ranged from 1.5 cm to 3.5 cm both in CT and in US. Depths of the RPN centers were from 3.5 cm to 7.0 cm in CT, and from 3.5 cm to 6.5 cm in US. Differences of sizes and depths between CT and US were from -0.5 cm to 0.5 cm and from 0.0 cm to 1.0 cm, respectively. RPNs that are 1.5 cm or more in size can be demonstrated with percutaneous US using CT guidance. This technique should be utilized for the purpose of monitoring in a radiation therapy setting.

Aged↗

Expression of caspase-activated deoxyribonuclease (CAD) and caspase 3 (CPP32) in the cochlea of cisplatin (CDDP)-treated guinea pigs.

Cisplatin, an anti-cancer drug, is known to induce apoptosis. During apoptosis, double-stranded DNA is broken into single-stranded DNA by the action of caspases and caspase activated deoxyribonuclease (CAD). We immunohistochemically examined the cochlea of guinea pigs for signs of the apoptosis after the administration of cisplatin. Cisplatin (10 mg/kg b.w.) was intraperitoneally injected to guinea pigs and 3 days later, the animals were sacrificed by intracardiac perfusion of 4% paraformaldehyde. The temporal bones were then removed and immunohistochemically stained for CAD and caspase 3, using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labelling method. CAD was observed in the stria vascularis and the spiral ligament. Caspase 3 was also detected in the stria vascularis, the spiral ligament and the supporting cells of the organ of Corti. These findings suggest that apoptosis is involved in the cochlear damage observed in cancer patients treated with cisplatin.

Animals↗

Foreign body in the maxillary sinus--possible plastic tube: a case report.

We experienced the case of a patient who had a foreign body in the maxillary sinus. The patient complained of recurrent unilateral badly smelling rhinorrhea. The computed tomography and the magnetic resonance images revealed a foreign body in the maxillary sinus. The foreign body was removed via the Caldwell-Luc approach. The foreign body was a plastic tube, which was supposed to be designed for the drainage of the maxillary sinus. However, the patient did not remember having been subjected to a treatment using such kind of tube. After the surgical removal, the patient became free from the nasal symptoms.

Adult↗

Induction of apoptosis in the vestibule of guinea pigs after middle ear inoculation with lipopolysaccharide (LPS).

OBJECTIVE: During the process of apoptosis, double-stranded DNA is broken into single-stranded DNA (ssDNA) by the action of caspases and caspase activated deoxyribonuclease (CAD). We immunohistochemically examined the apoptotic changes induced by endotoxin in the vestibule of guinea pigs. METHODS: Lipopolysaccharide (LPS) (5 mg/ml, 0.2 ml), a bacterial endotoxin, was transtympanically injected into the middle ear. 48 h after injection of LPS, animals were sacrificed by intracardiac perfusion of fixative. The temporal bones were then removed and immunohistochemically stained for ssDNA, CAD and caspase 3. RESULTS: ssDNA was detected after 48 h in the dark cell area of the LPS group, not in the sensory epithelium. CAD was observed both in the dark cell area and the sensory epithelium. Caspase 3 was also detected both in the dark cell area and the sensory epithelium. CONCLUSION: Our findings suggest that apoptosis is involved in the dysfunction of the vestibule under inflammatory conditions.

Animals↗

IL-5 and eotaxin levels in middle ear effusion and blood from asthmatics with otitis media with effusion.

OBJECTIVE: The purpose of this study was to evaluate eosinophil infiltration as well as IL-5 and eotaxin levels in middle ear effusion (MEE) and blood from otitis media with effusion (OME) patients with asthma and to compare the findings with those from OME patients without asthma (control group). MATERIAL AND METHODS: Levels of IL-5 and eotaxin in MEE and blood were measured by means of enzyme-linked immunosorbent assay. RESULTS: 5 levels in MEE were significantly higher than those in blood in both groups of patients and in OME patients with asthma than in the control group. In addition, in OME patients with asthma, there was a significant correlation between the percentage of eosinophils and IL-5 levels in MEE. Eotaxin levels in blood were significantly higher than those in MEE in both groups of patients and in OME patients with asthma than in the control group. In addition, in OME patients with asthma, the percentage of eosinophils and eotaxin levels in blood tended to correlate, but did not reach statistical significance. CONCLUSION: These data suggest that, in OME patients with asthma, eosinophilia in MEE depends more on IL-5 than on eotaxin, and that eotaxin may play an important role in the mobilization of eosinophils from the bone marrow into the blood.

Adolescent↗

Traumatic perilymph fistula in infants: a case report.

Traumatic perilymph fistula is reported to be rare in infants because of the small size of the infant external meatus. We treated an infant with a traumatic perilymph fistula in the right ear. A metallic wire had penetrated the tympanic membrane. Horizontal-rotatory nystagmus was also observed. Computed tomographic images revealed dislocation of the ossicles. The perilymph fistula was closed under general anesthesia. The incus-stapes joint was separated and the footplate of the stapes was dislocated. Leakage of the perilymph fluid was apparent from the oval window and this fistula was closed with connective tissue. The perforation of the tympanic membrane was closed with temporal fascia. After surgery, the spontaneous nystagmus disappeared. The patient is under observation as an outpatient and is growing normally.

Child, Preschool↗

Mast cell-IgE-and mast cell-structural cell interactions in allergic airway disease.

Allergic diseases like atopic rhinitis, bronchial asthma, and urticaria are prevalent and on the rise. Mast cells are known to play a central role in the immediate phase reaction of allergic diseases through the IgE-mediated release of a variety of chemical mediators like histamine, leukotrienes, and prostaglandins. On the other hand, T lymphocytes, basophils and eosinophils are thought to be responsible in inducing the late phase response. Yet, recent studies show that the mast cell cannot be simplistically assigned a role in the immediate phase allergic response, and that this cell plays a crucial role in ongoing allergic inflammation, including the development of hyper-responsiveness. In the present article, the author will try to discuss the integrated roles of mast cells in IgE-mediated allergic inflammation with specific emphasis on the roles of mast cell-IgE networking and mast cell-structural cell interactions in the late phase allergic response and chronic allergic inflammation.

Asthma↗

Expression of caspase-activated deoxyribonuclease (CAD) and caspase 3 (CPP32) in the hydropic cochlea of guinea pigs - second report.

Apoptosis was induced in the cochlea by the injection of keyhole limpet hemocyanin (KLH) into the endolymphatic sac of guinea pigs and immunohistochemically examined. Keyhole limpet hemocyanin was injected into the right endolymphatic sac. The temporal bones were fixed via cardiac infusion of fixative and immunohistochemically stained for caspase-activated deoxyribonuclease or caspase 3. Endolymphatic hydrops became evident in the cochlea 1 day after the injection of keyhole limpet hemocyanin (n=6). The temporal bones in the control group did not show any caspase-activated deoxyribonuclease or caspase 3 immunoreactivity (n=6). Immunoreactivity for caspase 3 was detected in the supporting cells of the organ of Corti, the stria vascularis and the spiral ganglion cells. Caspase-activated deoxyribonuclease was also detected in the same areas. These findings suggest that apoptosis is involved in the pathogenesis of endolymphatic hydrops. This phenomenon could lead to cochlear dysfunction, as seen in endolymphatic hydrops.

Adjuvants, Immunologic↗

Immunoreactivity for myeloperoxidase (MPO) in the vestibule after the injection of bacterial lipopolysaccharide into the middle ear.

OBJECTIVE: In this study, the effect of endotoxin on the vestibule of the ear of guinea pigs was immunohistochemically examined. METHODS: Bacterial lipopolysaccharide was injected into the middle ear transtympanically. After 48 h, the animals were sacrificed by intracardiac perfusion of fixative; then, the temporal bones were removed and processed for immunohistochemical staining with the anti-myeloperoxidase antibody. RESULTS: Myeloperoxidase could be detected after 48 h in the sensory epithelium and the dark cell area. CONCLUSION: It is reported that radical oxygen species, which are cytotoxic, are detected under inflammatory conditions. Our results suggest that myeloperoxidase and reactive oxygen species are involved in vestibular dysfunction under inflammation.

Animals↗

Incidence and characteristics of otosclerosis in the Japanese population.

OBJECTIVE: Otosclerosis is thought to be quite an uncommon disease in Japan. However, in recent years the incidence of this disease seems to have increased. Here we report about the characteristics and incidence of this disease in the Japanese population who underwent stapes surgery in our department. METHODS: A total of 80 patients (115 ears), who underwent stapes surgery by a single surgeon in 21 years and 8 months were included in this study. RESULTS: The incidence of clinical otosclerosis was found to be 0.22% among the outpatients with ear disease. During the first half of the period, the ratio of stapes surgery/tympanoplasty was less than 0.05. While, during the second half of this period, this ratio had increased to 0.08. The average number of stapes surgery performed in the first half period was 3.7 ears/year, and that in the second half was 6.8 ears/year. In contrast to otosclerosis in Caucasians, pure tone threshold in lower frequencies was much higher than that of higher frequencies (except for 8000 Hz). However, the improvement of the threshold after surgery was not so different from that reported in Caucasians. CONCLUSIONS: Taken together, the present results clearly demonstrate that the incidence of otosclerosis in Japan has been increasing. Moreover the rise in the slope of the conduction curve at higher frequencies may be a reflection of the pathological characteristics of otosclerosis in Japanese population, which is less invasive and has limited otosclerotic foci in the temporal bone.

Adult↗

Carboplatin induces less apoptosis in the cochlea of guinea pigs than cisplatin.

BACKGROUND: Cisplatin (CDDP) is known to cause inner ear damage while carboplatin (CBDCA) induces less ototoxicity than CDDP. We examined apoptotic changes in the cochlea of guinea pigs after injection of CDDP or CBDCA using immunohistochemical and electrophysiological techniques. METHODS: Three days after the injection of each solution, the cochleas were immunohistochemically examined for the presence of fragments of single-stranded DNA (ssDNA). The auditory brain stem response was recorded before and three days after the injection. RESULTS: We detected fragments of ssDNA in the stria vascularis and the spiral ligament of the CDDP-treated cochlea. In this group, the threshold of the auditory brainstem response was significantly elevated, however, in the CBDCA group, no apparent change of the threshold was detected. In the CBDCA group, fragments of ssDNA were detected in the stria vascularis and the spiral ligament. The number of cells that stained positive for ssDNA, was less than that in the CDDP group. CONCLUSIONS: Our findings indicate that CBDCA induces less apoptosis than CDDP and that this phenomenon contributes to the ototoxicity of CDDP.

Animals↗

Local injection of OK-432 in the treatment of ranula: a case report.

We treated a 57-year-old woman for ranula. After aspirating the cyst's contents, we administered 0.1 KE/ml of OK-432 via local injection. One month later, the cyst had still persisted, so we repeated the procedure. After 2 weeks, the ranula began to shrink markedly, and at 4 weeks it had almost disappeared. No recurrence of the ranula was observed during the subsequent 1 year of follow-up. Following each injection, the patient developed transient fever and local swelling but no serious complications. Our experience suggests that OK-432 injection is an effective treatment for ranula. However, because this treatment causes the cyst to collapse rather than disappear completely, patients should be regularly monitored over the long term.

Antineoplastic Agents↗

Nuclear-factor kappa B (NF-kappa B)-inducible nitric oxide synthase (iNOS/NOS II) pathway damages the stria vascularis in cisplatin-treated mice.

BACKGROUND: Cisplatin is reported to damage the stria vascularis of the cochlea. Free radicals, especially large amounts of nitric oxide catalyzed by inducible nitric oxide synthase, are considered to have an important role in this toxicity. The induction of inducible nitric oxide synthase is regulated by nuclear-factor kappa B (NF-kappa B). We examined the damage of the stria vascularis by immunohistochemical techniques. MATERIALS AND METHODS: Cisplatin (15 mg/kg b.w.) was injected intraperitoneally into the mice. Three days after the injection, the cochleas were immunohistochemically-stained using specific antibodies for nuclear-factor kappa B (NF-kappa B), inducible nitric oxide synthase (iNOS) or single-stranded DNA. RESULTS: NF-kappa B was expressed in the cisplatin-treated cochlea, especially in the stria vascularis and the spiral ligament. iNOS was also expressed in the stria vascularis and the spiral ligament. Fragments of DNA were observed only in the stria vascularis. CONCLUSION: The large amounts of NO catalyzed by iNOS led to inner ear dysfunction. Our results indicate that apoptosis is triggered by iNOS and that it mediates the ototoxicity induced by cisplatin.

Animals↗