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S Komiyama

Publications and source records attributed to S Komiyama.

At least 73 records · Page 4Linked to original sources
PubMed1996

Gadolinium blocks mechano-electric transducer current in chick cochlear hair cells.

We investigated the effects of gadolinium ion (Gd3+) on the mechano-electrical transduction (MET) current using a whole-cell patch electrode voltage clamp technique in dissociated cochlear hair cells of chicks. Gd3+ blocked the MET channel in a concentration- and voltage-dependent manner. At -50 mV, Gd3+ blocked the MET channel, with a Hill coefficient of 1.14 and a dissociation constant (KD) of 1.01 x 10(-5) M. Adaptation of the MET current disappeared after the introduction of Gd3+, a change that may be due to a decrease in inward going MET currents, specifically the Ca2+ component.

Animals↗
PubMed1996

Cyclin D1 overexpression in primary hypopharyngeal carcinomas.

BACKGROUND: Hypopharyngeal squamous cell carcinomas (HPCS) are associated with an extremely poor prognosis. Generally, conventional clinicopathologic factors have only limited value as prognostic factors for this malignancy. It is therefore clinically important to identify new prognostic factors that accurately reflect the biologic aggressiveness of this malignancy. The amplification and overexpression of the cyclin D1 protooncogene have been reported in a variety of malignancies, and are thought to be related to tumor progression. Based on this phenomenon, the authors immunohistochemically evaluated overexpression of the cyclin D1 gene in 42 cases of primary HPCS. In addition, the immunohistochemical staining of the proliferation marker MIB-1 (Ki-67 antibody) was also performed. METHODS: Formalin fixed, paraffin embedded biopsy specimens obtained prior to treatment were examined. Cyclin D1 and Ki-67 were detected using monoclonal antibodies by means of the streptavidin-biotin method. The relationship between cyclin D1 overexpression and the stage, histologic grade, presence of lymph node metastases, proliferation index, and survival was then statistically analyzed. The correlation between the proliferation index, other clinicopathologic factors, and survival was also evaluated. RESULTS: Twenty-three (54.8%) HPCS specimens showed a 20% or greater immunoreactivity for cyclin D1. Cyclin D1 overexpression was related to cervical lymph node metastases (P = 0.037) but not to clinical stage, histologic grade, or the proliferation index. Cyclin D1 negative tumors were associated with a significantly better prognosis (P = 0.023), particularly in patients who underwent multimodality treatment. Finally, the MIB-1 labeling index showed no correlation with either the clinicopathologic parameters or overall survival. CONCLUSIONS: Based on these findings, cyclin D1 immunohistochemical staining is considered to be useful, not only as a prognostic factor for HPCS, but also as a means of determining the optimum treatment for each individual patient. Conversely, the MIB-1 labeling index appears to have no clinical significance in HPCS.

Adult↗
PubMed1996

An in vitro invasion model for human renal cell carcinoma cell lines mimicking their metastatic abilities.

We developed a modified in vitro invasion assay system using monolayers of vascular endothelial cells. A type I collagen gel was formed in plastic dishes, and overlaid with type IV collagen. Calf pulmonary arterial endothelial (CPAE) cells were seeded onto these plates, and incubated until they reached confluence. Five human renal cell carcinoma cell lines with various metastatic potentials in vivo were then seeded on the monolayer CPAE cells, and their colony formation and invasion activities were examined for 9 days. At day 4, the highly metastatic cell lines increased the number of colony foci on monolayer CPAE cells several fold higher than their poorly metastatic counterpart. The horizontal spreading patterns were also different between poorly and highly metastatic cell lines. On day 9, the number of carcinoma foci that penetrated the monolayer of CPAE cells and type IV collagen sheets into type I collagen gels in highly metastatic cell lines greatly increased as compared with that of poorly metastatic cell lines. Our in vitro invasion assay using monolayer CPAE cells would be useful to evaluate protease activities and colony formation during invasion.

Animals↗
PubMed1996

Japanese cedar pollinosis and HLA-DP5.

Japanese cedar pollinosis is a type I allergic disease caused by Japanese cedar (Cryptomeria japonica) pollen. We investigated the association between the disease and HLA class II alleles by HLA-DNA typing using a PCR-SSOP method and found that the frequency of HLA-DP5 (DPA1*02022 and DPB1*0501) was significantly increased in the patients. To investigate whether the HLA-DP5 molecule is directly involved in the pathogenesis of the disease, Japanese cedar pollen antigen (CPAg)-specific T cell lines were established from 3 patients who possessed HLA-DP5 (DPA1*02022/ DPB1*0501). By using these CPAg-specific T cell lines and HLA class II-expressing L-cell transfectants, we found that disease-associated HLA-DP5 restricted T cells specific for CPAg existed in the patients. Furthermore, among 38 synthesized overlapping peptides spanning the entire length of one of the major Japanese cedar pollen allergens, Cry j 1, an immunodominant peptide which induced HLA-DP5 restricted Th2 was identified. These observations suggest that the HLA-DP5 may be involved, at least in part, in the pathogenesis, by helping the IgE antibody production against CPAg.

Adolescent↗
PubMed1996

[Sudden sensorineural hearing loss associated with anticardiolipin antibody].

We experienced three female patients with sudden sensorineural hearing loss. All the patients showed elevation of anticardiolipin antibody in the serum. Immunoglobulin (Ig) M anticardiolipin antibody was present in case 1 (a 34-year old woman). IgG anticardiolipin antibodies were present in cases 2 (a 50-year-old woman) and 3 (a 9 year old girl). The patient in case 1 showed hearing disturbance of low tone in the left ear and normal vestibular function in both ears. The case 2 patient had an average hearing level of 81.7dB at 0.5. 1, and 2kHz and severe canal paresis in the right ear. In case 3 the patient showed an average hearing level of 53.3dB in the right ear and normal vestibular function in both ears. It was suggested that thrombosis which might have been induced by anticardiolipin antibody could have caused the sudden sensorineural hearing loss in these patients. Steroid therapy cured the hearing disturbance completely in case 1. Steroid and prostaglandin E1 therapy did not improve the hearing disturbance in case 2. Steroid, prostaglandin E1, and ticlopidine hydrochloride therapy improved the hearing disturbance in case 3. It appears that not only steroids but also prostaglandin E1 and ticlopidine hydrochloride therapy may be effective in patients with sensorineural hearing loss associated with anticardiolipin antibody.

Acute Disease↗
PubMed1995

Voltage-dependent Ca2+ channels in the spiral ganglion cells of guinea pig cochlea.

Voltage-dependent Ca2+ channels in spiral ganglion cells (SGCs) isolated from guinea pig cochlea were investigated using the patch-clamp technique in a whole-cell recording mode. The voltage-dependent Na+ and K+ currents were blocked by adding tetrodotoxin, 4-aminopyridine, and tetraethylammonium to the external solution and by using choline or Cs+ in the external and internal solutions instead of Na+ or K+, respectively. The depolarizing voltage steps evoked inward currents with slow current decay. The maximum amplitude of the inward current increased in a hyperbolic manner with increasing extracellular Ca2+ concentration, indicating that the inward current was a voltage-dependent Ca2+ current (ICa). In 5 mM Ca2+ external solution, the ICa activated from a membrane potential around -60 mV and reached full activation at about -10 mV. The ICa inactivated from about -60 mV and became fully inactivated at about O mV, consistent with the high-voltage-activated Ca2+ channel subtype. Ionic selectivities for Ca2+ channels in SGCs were as follows: Ca2+ > Ba2+ > Sr2+. Effects of both inorganic and organic Ca2+ antagonists also were examined. The inhibitory strength was as follows: La3+ > Cd2+ > Ni2+ > or = Co2+ for inorganic Ca2+ antagonists, and flunarizine > nicardipine > methoxyverapamil > diltiazem for organic ones.

4-Aminopyridine↗
PubMed1995

Disturbance of regulation of sodium by cis-diamminedichloroplatinum in perilymph of the guinea pig cochlea.

We studied the acute effects of cis-diamminedichloroplatinum (CDDP) on the cochlear partition and inner ear fluid in the guinea pig. At 48 hours after the administration of a single intramuscular injection of CDDP, 12.5 mg/kg of body weight, the endocochlear resting potential (EP) was significantly decreased to 32.1 +/- 1.8 mV in the treated animals, versus 80.6 +/- 1.0 mV in the control animals. There was a significant rise in potassium (K+), sodium (Na+), and chlorine (Cl-) in the endolymph of the animals treated with CDDP as compared with the control animals. Only Na+ was found to increase significantly in the perilymph, reaching more than twice the level of the control animals; both K+ and Cl- remained within the normal range. Serum electrolytes also remained within the normal range. Evaluation of modified ionic permeabilities across the endolymph-perilymph barrier showed an apparent increase in Na+ permeability and a normal range of K+ and Cl- permeabilities. Histopathologic examination of the cochlea showed a moderate collapse of the endolymphatic space, with atrophy of the stria vascularis and destruction of the outer hair cells. The findings suggest that the acute changes produced in the cochlea by administration of CDDP were attributable to a breakdown in the regulation of Na+ metabolism in the perilymph.

Animals↗
PubMed1995

[Steroid-responsive sensorineural hearing loss with low tone loss].

Five cases of sensorineural hearing loss of sudden onset were reviewed. They were not responsive to administration of ATP and Vit. B12, but very responsive to steroid administration. All the patients were male and showed hearing loss in low frequencies in pure tone audiogram. Administration of steroid recovered hearing impairment immediately. However, cessation of steroid aggravated the recovered hearing. Serological and immunological examinations did not show any abnormal findings on all the patients. It was considered that these five patients had characteristics of both steroid-sensitive and low tone-loss type sensorineural hearing losses.

Administration, Oral↗
PubMed1994

Carotid body tumor associated with differentiated thyroid carcinoma.

We report a case of a carotid body tumor associated with a primary differentiated thyroid carcinoma. A 44-year-old woman presented with a 10-year history of an asymptomatic mass in her neck. Physical examination revealed a pulsatile submandibular mass in her right neck as well as multiple nodules in the thyroid. Magnetic resonance imaging, computed tomography and, in particular, angiography were diagnostic of the carotid body tumor. Slight changes in serum thyroglobulin levels and thyroid scintigraphy led us to suspect thyroid carcinoma. Embolization of the arteries feeding the carotid body tumor was performed, and was followed by tumor resection 24 h later. At surgery, histopathology confirmed the presence of follicular and papillary carcinomas of the thyroid, resulting in concurrent resection of the gland. There were no residual cranial nerve deficits. The patient subsequently received radiotherapy. Diagnosis and surgical management are discussed, together with pathogenetic factors.

Adult↗
PubMed1994

Pharyngoesophageal pressure in patients with swallowing disorders.

We developed and tested a pressure transducer to correctly determine swallowing pressure at different sites in the pharynx. In normal individuals three pressure peaks were obtained in the mesopharynx, hypopharynx and cervical esophagus, respectively. A patient with central dysphagia demonstrated markedly low mesopharyngeal and hypopharyngeal swallowing pressure. One tongue cancer patient who had undergone right hemiglossectomy, including partial resection of the root of the tongue and bilateral superior neck dissection, had markedly low swallowing pressure in the mesopharynx and vallecula area. Another supraglottic cancer patient treated by supraglottic horizontal partial laryngectomy showed extremely low swallowing pressure in the supraglottic area. Based on our findings, we suggest that measurements using a pressure transducer such as the one described here should be used in combination with radiographic study to diagnose swallowing anomalies correctly. Data obtained with the pressure transducer will allow the clinician to identify the site responsible for postoperative dysphagia as well as its severity, and facilitate planning of reconstructive surgery when required.

Adult↗
PubMed1994

Factors that affect swallowing-related apnea times in humans.

The dynamics of deglutition were studied in relation to potential changes due to aging. Swallowing-related apnea time (SAT) was measured during "dry" and "wet" swallowing in 84 adults without dysphagia to examine if age-related variation of SAT corresponded to changes in deglutition dynamics due to aging and to determine possible significance. Swallowing movements were recorded using a transducer for measuring swallowing pressures. Respiratory flow rates during deglutition were measured with a heat-wave flowmeter as part of phonatory function testing system. Respiratory movements were recorded with a respiration pick-up band set at the diaphragm. Findings demonstrated that SAT did not change with aging but was prolonged in subjects over age 50 years. When topical anesthesia was omitted during study, SAT tended to be shorter during wet swallowing than during dry swallowing in all age groups. Statistically significant differences were observed between wet and dry swallowing SAT in subjects under the age of 39 years. When a topical anesthetic was applied to pharyngeal mucous membranes, SAT was prolonged. Finally, SAT results during wet swallowing determined in a anesthetized dog before and after topical anesthesia of the pharyngeal mucous membranes showed significant prolongation after topical anesthesia. These findings suggest that the sensation of the pharyngeal mucous membrane may be important in producing swallowing-related apnea and controlling its duration.

Adult↗