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Biomedical subjects

M Toriyama

Publications and source records attributed to M Toriyama.

At least 19 recordsLinked to original sources
PubMed2001

Morphological changes of vestibular ganglion cells in human fetuses and in pediatric patients.

The temporal bone histopathology of human vestibular ganglion cells of fetuses and pediatric patients was studied. In the first study, we traced the morphological changes in vestibular ganglion cells in human fetuses ranging from 13 weeks to 39 weeks of gestational age by using 13 temporal bone serial sections. Vestibular ganglion cells had reached histological maturity by the 24th week of gestation and the volume of vestibular ganglion cell cytoplasm increased until the 39th week of gestation. In the second study, the temporal bone serial sections of seven neonates, eight infants and five children were investigated to reveal pathological changes in vestibular ganglion cells. Morphological changes in vestibular ganglion cells in human fetuses were revealed. Vestibular ganglion cells were changed pathologically by intracranial disease and variety etiology affecting the inner ear, because these are located in the internal auditory canal between the brain and labyrinth.

Child↗
PubMed2001

Stereoselective reactions. XXXIV. Enantioselective deprotonation of prochiral 4-substituted cyclohexanones using chiral bidentate lithium amides having a bulky group instead of a phenyl group on the chiral carbon.

Using chiral bidentate lithium amides having a bulky group instead of a phenyl group on the chiral carbon, enantioselective deprotonation of prochiral 4-substituted cyclohexanones in the presence of excess trimethylsilyl chloride was examined in THF in the absence and in the presence of HMPA. It is shown that enantioselectivity of the reactions decreases as the substituent on the chiral carbon of the chiral lithium amides and the substituent at the 4-position of cyclohexanones become reasonably bulky. An eight-membered cyclic transition state model is proposed for this deprotonation reaction.

Cyclohexanones↗
PubMed2000

[Histopathological study of the temporal bones in patients with primary carcinomas of the ear].

The most common symptoms of patients with carcinomas of the middle ear or mastoid are otorrhea, facial paralysis, and hearing loss, including a sensorineural element and vertigo. The latter two symptoms are indicators of inner ear damage. However, few reports have been made concerning the histopathological changes that occur in the inner ear in the presence of a tumor. The present study was performed to determine the pattern of tumor invasion in the inner ear and the histopathological changes that occur in the inner ear in cases of ear carcinomas. Temporal bone sections from five patients (age: #39-73 years; 3 males and 2 females) who died from a primary carcinoma of the ear were studied histologically. The following features were examined: 1) localization of the tumor in the temporal bone, 2) pattern of tumor invasion in the inner ear, 3) pathological changes in the inner ear, including the cochlea, vestibule and semicircular canals. Tumor cells were still present in the temporal bone sections of all the patients except one, even though the patients had received various treatments for the carcinoma, including radiation therapy, surgery and chemotherapy. Marked inflammatory and necrotic changes were observed in cases where the tumor had invaded the external auditory canal, middle ear cleft, internal auditory canal, and in some cases the inner ear. In cases where the tumor invaded the inner ear via the internal auditory canal rather than directly from the middle ear, the otic capsule is thought to have acted as a barrier against tumor invasion. In addition, marked degenerative changes throughout the entire inner ear structures were noted. These changes may have arisen from an attenuated blood supply to the inner ear as a result of pressure from the tumor in the internal auditory canal, tumor infiltration of the labyrinthine artery.

Adult↗
PubMed1999

Isolation and characterization of low density detergent-insoluble membrane (LD-DIM) fraction from sea urchin sperm.

The low density detergent-insoluble membrane (LD-DIM) fraction was obtained by a sucrose-density gradient centrifugation from sperm of three sea urchin species, Hemicentrotus pulcherrimus, Strongylocentrotus purpuratus, and Anthocidaris crassispina. These LD-DIM preparations were characterized by enriched glycosphingolipids (GSL) including gangliosides and sulfatide (SLF), having more than 50% of the total amount of GSL present in these sperm. Interestingly, a minor component of H. pulcherrimus sperm (HO3S-->8Neu5Acalpha2-->8Neu5Acalpha2-->6Glcbeta1++ +-->Cer) was shown to be even more enriched in the LD-DIM as revealed by using monoclonal antibody (mAb.3G9) speific to this ganglioside. In addition to the GSL, phosphatidyl-serine (PS) and diacylglcerol (DG) were enriched in the LD-DIM. On the other hand, cholesterol (CL) and sphingomyelin (SM) were not so enriched, which contrasted with the LD-DIM from Madin-Darby canine kidney (MDCK) cells, where CL and SM were reported to be abundant. Because mammalian somatic cell-derived DIMs have been proposed to be associated with functional signal transduction, it seems possible that the ganglioside-enriched LD-DIM in sea urchin sperm can participate in binding to eggs and the subsequent egg activation process. To our knowledge this is the chemical characterization of the LD-DIM fraction of a gametic cell.

Animals↗
PubMed1999

Initial anchoring and proliferation of fibroblast L-929 cells on unstable surface of calcium phosphate ceramics.

Calcium phosphate ceramics constructed from beta-tricalcium phosphate (TCP) and hydroxyapatite (HAP) have been successfully used as implant materials. However, there is a possibility that these materials are responsible for an unwanted inflammatory response during wound healing. Since TCP is soluble in the body, the instability of this material may contribute to this inflammatory response. Using composite ceramics of TCP and HAP that possessed Ca/P molar ratios of 1.50, 1.55, 1.60, 1.64, and 1.67, the effect of surface instability on fibroblast L-929 cells was investigated. The time-dependent variation of the initial anchoring ratio, cell density, and cell viability were measured. In general, the cells were severely damaged and ruptured on the highly soluble thin surface layer of the TCP-HAP ceramics. The initial anchoring ratio for TCP-HAP ceramics was as high as that for the polystyrene dish (Lux, control). However, viability at 6 h decreased to less than 50% of the initial cell density on ceramics with a Ca/P molar ratio of 1.64 (20% TCP-80% HAP), while 85% of the cells were viable on Lux. The viability on 100% TCP, whose surface is the most highly soluble among the TCP-HAP ceramics used in this study, was reduced to 20%. Morphological observation showed that the anchored cells were ruptured when grown in culture medium on the 100% TCP. Although the high solubility of the thin surface layer on the TCP-HAP ceramics of the carrier was found to be the dominant factor in the decreasing cell viability, the initial viability was enhanced by the stabilization of the surface of the TCP-HAP ceramics by pre-incubating the scaffolds in a culture medium containing 10% fetal bovine serum for 3 d.

Journal Article↗
PubMed1999

Visualization of a recombinant gene protein in the baculovirus expression vector system using confocal scanning laser microscopy.

Expression of the recombinant protein beta-galactosidase in the Spodoptera frugiperda Sf-9 insect cell line infected by the Autographa californica nuclear polyhedrosis virus expressing beta-galactosidase (AcNPV-betagal) was visualized using confocal scanning laser microscopy with fluorescent staining of both the recombinant protein and the cell nucleus. The average size of the insect cells and the intracellular DNA concentration both increased markedly, respectively reading 3.8- and 2.3-fold the values before infection. The average beta-galactosidase activity began to increase at 20-24 h post infection and finally reached 1.9 x 10(4) units/ml. As the post infection time increased, the stained nucleus images expanded and spread broadly. Beta-galactosidase was first identified by fluorescent staining at 12 h post-infection, filled the cell at 27 h, began to be released at 36 h, and finally spread out of the cell. The locations of the nucleus and expressed beta-galactosidase were identified from computerized tomograms and 3-dimensional images.

Journal Article↗
PubMed1998

Matrix metalloproteinase digestion of aggrecan in human cartilage tumours.

Substantial experimental and clinical evidence suggests that the catabolism of extracellular matrix components is a prerequisite for invasive and metastatic behaviour of solid tumours. Chondrosarcomas are malignant cartilaginous tumours that most commonly arise in bone, and the large aggregating proteoglycan aggrecan is a major component of the extracellular matrix of these tumours. Matrix metalloproteinases (MMPs) have been implicated in tumour invasiveness. The purpose of this study was to determine whether MMPs play a role in aggrecan catabolism in cartilage tumours. In order to detect aggrecan digestion products resulting from in vivo cleavage at the MMP site, protein extracts from human articular cartilage and from various cartilage tumours were analysed by Western blot using an antibody to the FVDIPEN neoepitope generated by MMP cleavage. Examination of cartilage extracts revealed a trend of increasing aggrecan digestion at the MMP site with age. One hyaline chondrosarcoma and three osteochondromas lacked detectable aggrecan fragments with the carboxy terminal FVDIPEN neoepitope. Two osteochondromas gave weak signals. However, all chondrosarcomas with degenerating extracellular matrix or with a myxoid component exhibited strong FVDIPEN immunoreactivity. These results demonstrate that, in contrast to the benign cartilage tumour osteochondroma, human chondrosarcomas contain abundant aggrecan degradation products resulting from cleavage in vivo at the MMP site in the interglobular domain. These data support the concept that MMPs participate in the degradation of extracellular matrix in chondrosarcoma, allowing the neoplastic chondrocytes to escape local confinement, migrate, and invade neighbouring and remote tissues.

Adult↗
PubMed1998

Cochlear neuronal loss are determined by use of a neurofilament protein antibody in cases of bilateral profound deafness.

The temporal bones of two patients with profound bilateral deafness from infancy were studied immunohistochemically, using a neurofilament protein antibody to detect the cochlear neuronal elements. One patient exhibited Mondini dysplasia of the inner ear, with the organ of Corti almost completely deteriorated. The other patient is the first reported case involving complete aplasia of the organ of Corti in all turns. In both cases, the immunohistochemical staining clearly revealed a severe reduction in the number of afferent neurons, such as dendrites, spiral ganglion cells and cochlear axons. The number of efferent spiral bundles in the osseous spiral lamina and intraganglionic portion also decreased in parallel with the reduction in the number of cochlear afferent neurons. Our results are inconsistent with previously reported cases of presbycusis and acquired deafness induced by the measles virus, in which efferent neurons were preserved while afferent neurons degenerated. The loss of both the efferent and afferent neurons might be characteristics of congenital deafness.

Aged↗
PubMed1997

Surface instability of calcium phosphate ceramics in tissue culture medium and the effect on adhesion and growth of anchorage-dependent animal cells.

The surface of biocompatible ceramics made of synthesized hydroxyapatite (HAP) and beta-tricalcium phosphate (TCP) was found to be extremely active in tissue culture medium. Using mixed ceramics of HAP and TCP which had been prepared with different Ca/P molar ratios adjusted in stepwise fashion to values of 1.50, 1.55, 1.60, 1.64 and 1.67, the characteristics of the surface were investigated. The time-dependent variation of zeta potential of the TCP-HAP ceramics immersed in distilled water and in culture medium with and without addition of fetal bovine serum showed that the surface was unstable with significant changes in the charge being observed. Dry TCP powder had a zeta potential of -19 mV, which shifted to -7 mV after soaking in water and to -26 mV in culture medium. In contrast, HAP had a zeta potential of -11 mV in a dry state, -9 mV in water and -29 mV in culture medium. Concentrations of calcium and phosphate dissolved in distilled water showed the solubility was higher for TCP than for HAP. In comparison, it was found that dissolved calcium and phosphate in the medium were removed from the solution by deposition on immersed TCP-HAP ceramics. These results suggested that the stability of the surface was closely related to both reactions of association and dissociation of calcium and phosphate in tissue culture medium. The zeta potential analysis also suggested that Ca-deficient HAP, which has a similar crystal structure to HAP with a Ca/P ratio less than 1.67, was generated by degradation and reforming of the surface layer. The most stable structure which was the most suitable for adhesion of L-929 cells was obtained by the mixture of 20% TCP and 80% HAP ceramics. In conclusion, the stability of the surface structure was considered to be the dominant factor for the enhancement of the adhesiveness of cells on TCP-HAP ceramics.

Animals↗
PubMed1997

Growth of calcium phosphate on phosphorylated chitin fibres.

Calcium phosphate growth on chitin phosphorylated fibres was studied using scanning electron microscopy and energy dispersive X-ray analysis (SEM, EDX), micro-Fourier transform infrared spectroscopy (FTIR), and solid state magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. The C6 chemical shift positions of 13C MAS NMR in the chitin fibres phosphorylated using urea and H3PO4 are obvious indicating that phosphorylation takes place not in the C1 but in the C6 region. Micro-FTIR and 31P MAS NMR suggested that ammonium hydrogen phosphate formed during the phosphorylation procedure. Chitin fibres phosphorylated using urea and H3PO4 and then soaked in saturated Ca(OH)2 solution at ambient temperature, which lead to the formation of thin coatings formed by partial hydrolysis of the PO4 functionalities, were found to stimulate the growth of a calcium phosphate coating on their surfaces after soaking in 1.5xSBF solution for as little as one day. The thin layer after Ca(OH)2 treatment functioned as a nucleation layer for further calcium phosphate deposition after soaking in 1.5xSBF solution. EDX-measured Ca : P ratios of the coatings of Ca(OH)2-treated phosphorylated chitin in 1.5xSBF solution suggested that calcium-deficient apatite was formed.

Journal Article↗
PubMed1997

The role of transforming growth factor-beta in PEG-rHuMGDF-induced reversible myelofibrosis in rats.

Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) injected at a suprapharmacologic dose (100 microg/kg) daily for 5 d in normal rats caused marked increases in marrow megakaryocytes and platelet counts at 6-8 d followed by gradual decreases to control levels at 10-20 d. Interestingly, in addition to the expected thrombopoiesis, PEG-rHuMGDF was associated with myelofibrosis with a predominance of reticulin fibres at day 10 followed by complete normalization by day 20. At 6-8 d, the levels of transforming growth factor-beta1 (TGF-beta1) in the extracellular fluid of the marrow, the platelet poor plasma, and the platelet extract were increased 23-, 7- and 2-fold, respectively. The elevated levels of TGF-beta1 were gradually reduced to baseline levels at 13-20 d in accordance with the normalization of myelofibrosis and thrombopoiesis. An ultrastructural analysis showed that large fragments of megakaryocytes were deposited in the marrow parenchyma of PEG-rHuMGDF-treated rats at day 6. PEG-rHuMGDF administration at pharmacologic doses (1 and 10 microg/kg) did not induce the deposition of reticulin fibres in the marrow. These findings suggest that TGF-beta1 leaked from megakaryocytes is involved in the development of the PEG-rHuMGDF-induced myelofibrosis and that this is a reversible process related to the regulation of the excess production of platelets.

Animals↗
PubMed1997

[Histopathological studies of temporal bones of patients with malignant melanoma].

Although malignant melanoma is known to metastasize to various sites including the temporal bones, there have been few studies on temporal bone histopathology in malignant melanoma. Here we describe the temporal bone histopathology of 5 patients (10 temporal bones) who died of malignant melanoma with multiple metastasis to many internal organs and bones. We investigated the temporal bone based on the following three points: 1) the presence of metastatic lesions in the temporal bone, 2) inner ear pathology, and 3) the distribution of melanin in the inner ear. Normal melanin distribution was also studied in 35 temporal bones of patients without malignant melanoma. Metastatic malignant melanoma was observed in 5 temporal bones from 3 patients, in two of whom the internal auditory canal was involved bilaterally by melanoma cell infiltration. In the remaining patient (one ear), metastatic melanoma was found along the dura mater of the posterior cranial fossa to the mastoid air cells. In the former two patients, the inner and outer hair cells as well as the stria vascularis showed degenerative changes to various extents. In particular, the inner ear changes were severe in the ear with the decongestion of the inner ear vessels. Melanin was found in the modiolus, stria vascularis, osseous spiral lamina, membranous labyrinth, and endolymphatic sac, as previously reported. The amount of melanin in the inner ear increased with age in the control patients, but was greater than in the controls, in all of the cases of malignant melanoma except one, in which metastatic lesions were present in the internal auditory canal with marked congestion of the inner ear vessels.

Adult↗
PubMed1997

Analysis of giant cell tumor of bone with pulmonary metastases.

The authors reviewed 6 cases of giant cell tumor of bone with pulmonary metastases, analyzed the growth rate of the metastases, and performed flow cytometry on paraffin blocks from primary and metastatic lesions. Surgery on the pulmonary metastases was done in 3 cases. Chemotherapy was administered in all 6 cases. If the doubling time of the pulmonary metastases was more than 80 days, the case was considered to be slow growing or in regression. However, if the doubling time was approximately 30 days, the prognosis was poor. The cases were divided into 3 types according to the prognosis. After chemotherapy (cyclophosphamide), the pulmonary metastases decreased in size in 2 cases. In 2 other cases, the metastases were slow growing, and the remaining 2 patients died early. Flow cytometric analysis was performed on primary and metastatic lesions, which showed a diploid pattern in most cases, but a tetraploid pattern in 1 recurrent case. Pulmonary metastatic lesions displayed a diploid pattern in 4 cases from which materials were taken either at surgery or autopsy.

Adolescent↗
PubMed1996

[Clinical characteristics of chronic sinusitis with different lower respiratory tract diseases].

We determined the clinical characteristics of chronic sinusitis in patients with different lower respiratory tract diseases. Sinusitis was divided into three groups. The first group was sinusitis with bronchial asthma. The second group was sinusitis with chronic bronchitis, bronchiectasis or diffuse panbronchiolitis. This type of sinusitis is generally called sinobronchial syndrome (SBS). The third group was sinusitis without lower respiratory tract disease. Because the pathogenesis of these lower respiratory tract diseases differs with the diseases, the pathogenesis of sinusitis accompanied by these lower respiratory tract diseases also may be different. Clinical and laboratory examinations used in this study were rhinoscopy, X-ray examination of the paranasal sinuses, cytological study of nasal secretion and the saccharin test for the muco-ciliary function of the nasal mucosa. By rhinoscopic examination, no difference was found in the size of the nasal polyp among three groups. The results of other examinations were as follows. X-ray examination: Involvement of the ethmoid sinuses was greater than that of the maxillary sinuses in the patients with sinusitis with bronchial asthma. In contrast, involvement of the maxillary sinuses in SBS patients was greater than that of the ethmoid sinuses. Cytology of nasal secretion: Dominant inflammatory cells in the patients with sinusitis with bronchial asthma were eosinophils, while neutrophil were more frequently found in the SBS patients. Saccharin test: Most of the patients with bronchial asthma showed normal responses. In the SBS patients, however, only a few patients showed a normal response and the others showed prolonged responses. Clinical characteristics of the patients with sinusitis without lower respiratory diseases were more similar to those of the SBS patients. In conclusion, there were distinct differences in these clinical characteristics between sinusitis with bronchial asthma and SBS. These results suggest that the pathogenesis or the inflammatory process of sinusitis is heterogeneous and whether the inflammation is allergic or not may be important.

Adult↗
PubMed1996

[Hearing acuity in the elderly in Japan].

In Japan, the elderly population has progressively increased. It is therefore expected that various social services for the elderly will be demanded. As most of the elderly have hearing impairment due to presbycusis, it is difficult to communicate smoothly with them. To provide the various social services, it is necessary to investigate hearing acuity in the elderly. Accordingly, the Hearing Research Group, which belongs to the Research Project on Aging and Health in the Ministry of Health and Welfare of Japan, investigated the hearing acuity of people 65 years old, or more. One thousand one hundred ninety two subjects were divided into five groups, Group A consisted of 170 males and 216 females between 65 and 69 years old, Group B, 186 males and 158 females between 70 and 74; Group C, 147 males and 140 females between 75 and 79; Group D, 63 males and 61 females between 80 and 84; and Group E, 29 males and 22 females 85 years old or more. We examined the 175 subjects 80 years old or more. Therefore, it is considered that this study could indicate the present condition of hearing acuity of the elderly of Japan. The average hearing levels measured at seven frequencies (125, 250 and 500Hz, and 1, 2, 4, and 8KHz) were 35.0dB in group A, 42.1 in group B, 46.1 in group C, 52.1 in group D, and 55.6 in group E. There were no differences in the average hearing level between males and females in any group. The audiogram pattern indicated a gradually descending curve in most subjects in all groups. The average speech discrimination rate was 75.4% in group A, 70% in group B, 63.8% in group C, 59.7% in group D, and 52.1% in group E. The percentage of subjects showing a short increment sensitivity index of more than 70% was 45.2% in group A, 49.3% in group B, 47.9% in group C, 51.6% in group D, and 59.7% in group D. In conclusion, hearing loss due to aging tended to be more progressive at higher frequencies while hearing acuity of frequencies covering normal speech was preserved. However, the speech discrimination rate decreased relative to changes in the pure tone hearing level. It was considered that the pathology of hearing loss due to aging begins with retrocochlear changes and cochlear factors are added to retrocochlear changes with aging.

Aged↗
PubMed1996

Radical radiotherapy for T3 laryngeal cancers.

PURPOSE: Evaluation of the local control rate and voice preservation probability in radically irradiated patients with T3 laryngeal cancer. PATIENTS AND METHODS: From 1974 through 1992, 37 previously untreated patients with T3 laryngeal cancer (supraglottic 15, glottic 22) were treated with initial radical radiotherapy and surgery for salvage. RESULTS: Two-year local control rate with radiotherapy alone, ultimate voice preservation rate, and ultimate local control rate for T3 supraglottic cancer were 33%, 33%, and 60%, respectively. Corresponding figures for T3 glottic cancer were 32%, 23%, and 77%, respectively. Five-year cause-specific survival rate for T3 supraglottic cancer and glottic cancer were 47% and 77%, respectively. In T3 supraglottic cancer, none of the 4 patients with subglottic tumor extension attained local control by radiotherapy alone, and local-regional recurrence-free time were significantly shorter in patients with subglottic tumor extension or tracheostomy before radiotherapy. There were no serious late complications such as chondronecrosis, rupture of carotid artery attributed to radical radiotherapy, while 3 patients had severe laryngeal edema requiring total laryngectomy. CONCLUSION: Current results indicated that initial radical radiotherapy and surgery for salvage might be an option for some patients with T3 laryngeal cancer.

Adult↗