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Biomedical subjects

K Miyata

Publications and source records attributed to K Miyata.

At least 307 records · Page 17Linked to original sources
PubMed1990

[Fine morphological studies on the connective tissue core and the epithelial cells of the lingual papillae in Mogella wogura wogura].

The three-dimensional structure of the connective tissue core (CTC) of each type of lingual papillae of Mogella wogura wogura was studied by scanning electron microscopy after removal of the epithelial cell layer and compared with the results obtained from light microscopy as well as transmission electron microscopy. Filiform papillae are densely distributed on the dorsal surface of the anterior part of the tongue. They were conical in shape and their connective tissue cores (CTCs) resembled wooden spoons at the tip of the tongue, while they were flower-shaped (Lysichiton camtschatense) at the middle part of the tongue. Fungiform papillae which had a round depression on the top were distributed sporadically among the filiform papillae, and contained columnar CTC with several plane striations running longitudinally along the lateral surface. A pair of vallate papillae was located at the boundary between the anterior and posterior tongue. Their CTC were flower shaped closely resembling a carnation. Giant conical papillae occupied the posterior marginal region of the tongue. These papillae contained much smaller conical CTC similar to the outer form. Light and transmission electron microscopic observations of the dorsal lingual epithelium revealed three different regions: anterior region to the filiform papillae, posterior to the papillae and interpapillary region. In the intermediate layers between the germinal layer and the surface layer of the anterior region to the filiform papillae, a large number of keratohyaline granules was observed, but the cornified layer was obscured. In the posterior region, keratohyaline granules were fewer in number and the cornified layer was clear and thick. In the interpapillary region, keratohyaline granules were few and a thin cornified layer was recognized. At higher magnification, small sized keratohyaline granules contained a large number of free ribosomes, suggesting a close relationship between the two. Odland bodies were found only on the interpapillary region.

Animals↗
PubMed1990

[Methicillin-resistant Staphylococcus aureus infection in the Kagoshima University Hospital--special attention to prevalence in otolaryngological infectious disease].

A retrospective study of the characteristics of MRSA (methicillin resistant S. aureus) in Kagoshima University Hospital and its ENT department was reported. There were 231 samples (104 strains) MRSA in all S. aureus 448 samples from Jan. to Sep. 1989 in Kagoshima University Hospital, in which 58 strains (55.8%) were coagulase type II and 35 strains (33.7%) were type VII. The much more predominant numbers of MRSA were observed in all the cases inpatients clinics in surgery, pediatrics, urology, gynecology and dermatology than internal medicine as well as outpatients clinics. In ENT department of this hospital, only 15.4% of all S. aureus were MRSA. On the other hand, bacteriological survey showed 26% of MRSA out of all S. aureus which were detected at Tokyo clinical research center on otorrhea in the patients with chronic otitis media as multicenter clinical trial of Japan. Two cases involved by MRSA after postoperative administration of many types of antibiotics were also demonstrated. These MRSAs were producing type II coagulase and very high concentrations of MICs to many antibiotics were observed. But these cases were not severe and MINO (minocyclin) or GM (gentamicin) were so effective. The effect of combined therapy of some antibiotics or antimicrobial agents was discussed briefly.

Anti-Bacterial Agents↗
PubMed1990

[A case of demyelinating disease showing a peculiar honeycomb-like and lamellar structure on magnetic resonance imaging].

A case of subacute demyelinating disease showing large honeycomb-like and lamellar lesions in bilateral cerebral white matter on MRI was reported. A 22 year-old woman felt general fatigue on sept. 30, 1988, and developed complete quadriplegia and mutism in about 10 days. She recovered shortly after high-dose corticosteroid therapy. She had neither fever nor meningeal irritation. There were no inflammatory changes in examinations of blood and CSF. On MRI, high and low signal areas of irregular shape in the cerebral white matter and brainstem, were observed on T2 and T1 weighted images, respectively, suggesting that the lesions are of demyelinating nature. These lesions appeared lamellar or honeycomb-like structures on T1 and T2 weighted image. This patient was diagnosed as having a subacute type of demyelinating disease similar to Balo's disease (concentric sclerosis).

Adult↗
PubMed1989

Fine structure of the filiform papilla of beagle dogs.

Light and electron microscopic examination of the dorsal lingual epithelium of beagle dogs (Canis domesticus) revealed three different regions: that anterior to the filiform papillae, that posterior to the papillae, and an interpapillary region. Whereas the basal and suprabasal cells are similar throughout, differences characterize the intermediate and surface layers. Keratohyalin granules are common in the intermediate layers in the anterior and interpapillary regions, tonofibrils are prominent in the posterior region, and no keratohyalin granules occur. The surface layer of the interpapillary region is not keratinized, that of the anterior region shows soft keratinization, and that of the posterior region shows hard keratinization. The perimeter of keratohyalin granules is composed of ribosomes 10-20 nm in diameter.

Animals↗
PubMed1989

Germanium myopathy: clinical and experimental pathological studies.

Pathological examinations were carried out on the skeletal muscle of a patient with germanium intoxication. The prominent histochemical finding was vacuolar myopathy with lipid excess, increased acid phosphatase activity and decreased cytochrome c oxidase activity. Ultrastructural lesions revealed a mitochondrial abnormality, autophagic vacuoles and accumulation of high electron-dense materials in deformed mitochondria and at the periphery of lipid droplets. Furthermore, the toxic effect of germanium on skeletal muscle was confirmed by the experimentally induced germanium myopathy, which showed autophagic degeneration, decreased cytochrome c oxidase activity and a mitochondrial abnormality with high electron-dense materials.

Child, Preschool↗
PubMed1989

A simplified Master's two-step test for preschool children.

To investigate the usefulness of a simplified Master's two step test (s-MTT) for preschool children aged 4-6, s-MTT was carried out in our pediatric cardiology clinic using a new stair and connector for joining the leads from each child to the ECG machine. The subjects were 21 children with Kawasaki disease without coronary involvement and four children with arrhythmias. The treadmill exercise test (TET) was done on the same day to compare the exercise load of s-MTT with that of TET. Oxygen uptake during s-MTT was also examined using another group consisting of eight outpatients. There were no differences in indices such as peak heart rate (HR), HR immediately after exercise, and performance ratio between the outpatients in this study and kindergarteners in the preliminary report. The proportions of peak HR and HR immediately after exercise in s-MTT to those in TET were 91.1 +/- 7.9 (mean +/- SD)% and 91.1 +/- 8.6%, respectively. The average oxygen uptake of the eight outpatients in s-MTT was 23.2 +/- 4.1 ml/min/kg. These studies suggest that the simplified MTT is useful as a screening test, because it can be done for all children aged 4-6 in any laboratory.

Cardiovascular Diseases↗
PubMed1989

Prediction of the virulencies of some enveloped viruses from the structure of the cleavage recognition site of viral glycoprotein essential for infectivity. II. Deviation analysis.

Analysis of the amino acid sequence in protein (deviation analysis) suggests that the binding between trypsin and the enveloped virus is the first step of their interaction, which occurs in a specified configuration. It is possible that the distance between their active sites is important for the viral sensitivity to trypsin, which is related to the virulency of the enveloped virus.

Amino Acid Sequence↗
PubMed1989

[Three dimensional structure of the connective tissue papillae of the tongue in Suncus murinus].

The surface structure of the connective tissue papillae (CP) of Suncus murinus tongue was observed by SEM after fixing with Karnovsky's fixative and removal of the epithelial cell layer with 3N or 8N HCl. On the surface of the slender conical tongue, there are densely distributed filiform papillae among which fungiform papillae are seen sporadically. A pair of vallate papillae are situated in the posterior region of the tongue. Filiform papillae appear somewhat different externally depending on the dorsal surface of the anterior tongue. At the tip of the tongue, filiform papillae are of a slender conical shape and have a slight depression in the anterior basal portion. The CP of these is seen as a spherical protrusion on which a shallow groove runs in the anteroposterior direction. In the middle region, somewhat large filiform papillae contain CP having one or two small round head-like structures on each spherical protrusion. These head-like structures are increased in number in the posterior region. In the most posterior region of the anterior tongue, there are distributed large filiform papillae having several slender protrusions that surround a basal anterior depression. These large branched filiform papillae have a glove finger like CP. Small conical filiform papillae are distributed in the posterior marginal region of the anterior tongue which have CP of a horse-shoe like protrusion that opens in the anterior direction. Spherical fungiform papillae have CP which are thick columnar in shape with many lateral thin folds running vertically and having a round depression on the top of each. CP of the vallate papillae appear as a beehive like structure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Anatomical studies on a supernumerary tooth considered to be a successional tooth of the lower first molar].

The purpose of this study is to investigate features of the successional tooth of the lower first molar. Materials investigated in this study deal with a supernumerary tooth formed at the distolingual deep part to the lower right first molar of a male patient aged twenty-four. It was observed with binocular microscopy and under X-ray. The occlusal surface of it was observed with scanning electron microscopy. Horizontal ground sections of it were prepared and observed with polarizing microscopy, fluorescent microscopy, and scanning electron microscopy. It is thought that this supernumerary tooth is a true successional tooth of the lower first molar because it was formed at the distolingual deep part to the lower first molar and the fissure of it is Y-shaped and it has five cusps. It is considered that two impressions at buccal and distal surfaces of it isn't original hereditary features but was accidentally formed by pressures of mesial and distal roots of the lower first molar. The rough form of it has most resemblance to the lower second premolar and distal and lingual parts of it are smaller than that of the lower first molar. But fundamental features of the lower first molar are preserved in it. It is thought that the center of the molarization field of human lower successional teeth lies at the successional tooth of the lower first molar because the form of the occlusal surface of it is more complex and functional than those of the lower first and second premolars.

Adult↗
PubMed1989

[Anatomical and histological studies on a microdontic wisdom tooth].

The purpose of this study is to investigate features and histological structures of the microdontic wisdom tooth. Materials investigated in this study deal with a very small upper right microdontic wisdom tooth of a male patient aged thirty-six. It was observed with binocular microscopy and under X-ray. Horizontal ground sections of it were prepared and observed with polarizing microscopy, phase microscopy, microradiograph, and scanning electron microscopy. Total length of this specimen was about 1/2 of the average measurement in Japanese upper third molars, breadth of the crown about 1/3, thickness of the crown about 1/4. It had one cusp and one root. It is considered that one cusp was formed by fusing of the mesiolingual cusp and mesiobuccal one because fundamental features of the buccal and lingual surfaces of upper molars were preserved in this specimen. It is thought that dental tubules in this specimen were formed more densely than those in the common wisdom tooth because the space of retreating odontoblasts of this specimen was limited but that enamel rods in this specimen were formed more thickly than those in the common wisdom tooth because the space of retreating ameloblasts of this specimen was wide. It is considered that the degeneration in this specimen came up to not only the dental form, but also the histological structure of the enamel because the surface layer of the enamel of this specimen was composed of the laminal structure.

Adult↗
PubMed1989

[Isolated angitis of the central nervous system--case report and review].

Isolated angitis of the central nervous system (IACNS) is rare condition with inflammation limited to vessels supplying the brain. This IACNS has been a poorly characterized and infrequently reported illness since it was first described as a separate entity in 1959. However, a patient with IACNS has not been reported in Japan. A patient, 39-year old-male, with IACNS limited to small and middle vessels is described. Recurrent, transient consciousness disturbances, focal myoclonus, papilloedema and temporal lobe epilepsy were observed during disease course. CSF finding of this patient showed lymphocytosis with marked increased protein. Carotid and vertebral angiogram showed irregular luminal outline in branches of all arteries. The most specific finding is that of alternating areas of focal stenosis and ectasia giving a "sausage" pattern. These characteristic findings showed in the branch of external carotid arteries. There was no evidence of systemic vasculitis by systemic angiography. Biopsy of temporal artery showed lymphocyte infiltration, fibrinoid necrosis without giant cell and granuloma. Formation of A-V malformation in the branch of external carotid artery was also observed. This histopathological finding was compatible with necrotizing angitis, not granulomatous angitis. Isolated angitis of the central nervous system was diagnosed. In spite of his administration of corticosteroid, cerebrospinal fluid abnormalities has not responded markedly. Abnormal findings of carotid and vertebral angiogram also has not changed. After 7 years from his onset, his neurologic signs and symptoms were well controlled with administration of anti-epileptic drugs.

Adult↗
PubMed1989

[Three-dimensional architecture of the connective tissue papillae of the mouse tongue as viewed by scanning electron microscopy].

The morphological relationship between lingual papillae and underlying connective tissue papillae of mouse was studied because it is conceivable that the differentiation of epithelium may be affected by its connective tissue. Tongues of adult male mice were fixed in formol or Karnovsky's fixative. After removal of the epithelium by long-term hydrochloric acid treatment at room temperature, the surface of the connective tissue papillae was observed by scanning electron microscopy. Connective tissue papillae that were fungiform in shape and which were distributed at the anterior part of the tongue showed barnacle-like protrusion after removal of the epithelium. Their surface was covered by numerous long filaments running vertically and there was a round depression on the top of each fungiform papilla that may be found to correspond to a taste bud when the results of light and electron microscopy are compared. Filiform papillae in a narrow sense were closely distributed in the anterior part of the tongue. They had a tapered tip declining posteriorly. Each filiform connective tissue papilla was conical in shape and had a round depression that slightly declined antero-downward, and a long narrow depression ran along the anterior edge of each connective tissue papilla. Large conical papillae which distributed at the anterior margin of the intermolar prominence had shovel-like connective tissue papillae which had a depression at the posterior surface unlike that of the filiform papillae. Branched papillae distributed in the posterior part of the prominence had a depression at the anterior surface. Under the light microscope, numerous keratohyaline granules were seen to be contained only in the posterior epithelial cell line of the large conical papillae distributed in the anterior margin of the prominence, while these granules were found only in the anterior epithelial cell line of both filiform and branched papillae. It became clear that the axes of each connective tissue papilla of large conical papillae distributed radically around a single midpoint. Connective tissue papillae of vallate papillae had a beehive-like shape and in follicate papillae there were several vertical elliptical gaps, seen when the epithelium was peeled from the connective tissue.

Animals↗
PubMed1989

[A new wound healing model using tissue cultured corneal endothelium. 1. Quantitative study of healing process].

A new in vitro model for evaluating endothelial wound healing has been developed. Rabbit and bovine corneal endothelial cells were cultured on coverslips in areas 8mm in diameter with hydroxyethyl methacrylate (HEMA) and monolayer sheets were obtained. Wounds were produced by scraping cells in the center of the cell sheets with a rotating silicone tip. The areas of these wounds were measured with computed planimetry. The average wound area was 3.00 +/- 0.21 mm2 in rabbit cell cultures 3.18 +/- 0.28 mm2 in bovine cell cultures. The healing process after making the wound was observed by inverse phase contrast microscope and wound healing rates were calculated. Wounded areas were covered by 60 hours in rabbit cultures, and by 84 hours in bovine cultures respectively. Wound healing rates during 6-12 and 12-24 hours were 92.5 +/- 11.9 microns 2/h, 62.4 +/- 3.4 microns 2/h in rabbits and 10.6 +/- 3.6 microns 2/h, 62.9 +/- 7.8 microns 2/h in bovine material respectively. The healing rates were higher in rabbit cultures than in bovine cultures. This model can be used for quantitative evaluation of the wound healing process of corneal endothelium.

Animals↗
PubMed1989

Effect of S-8666 on urinary Ca++ excretion in rats.

The effect of a novel uricosuric diuretic, S-8666, on urinary excretion of Ca++ was investigated in conscious rats. S-8666 acts mainly on the thick ascending limb of Henle's loop. Oral administration of S-8666 (3.2-316 mg/kg), furosemide (10-316 mg/kg) and trichlormethiazide (TCM; 0.01-10 mg/kg) caused natriuresis in a dose-dependent manner. However, the dose-response relationships for Ca++ and Na+ excretion differed slightly among these drugs. Na+ excretion was enhanced to the same extent by both S-8666 and furosemide, whereas Ca++ excretion induced by S-8666 was much smaller than that induced by furosemide. In the TCM group, there was no correlation between urinary excretion of Na+ and Ca++, but this was, if anything, a negative correlation. In the furosemide group, there was a highly significant positive correlation between these parameters with the slope of the regression line being 0.30 (g/Eq). In the S-8666 group, there was positive correlation between these parameters, but the slope of the regression line (0.13) was significantly lower than that in the furosemide group. The pattern of urinary Ca++ excretion as normalized by Na+ in the S-8666 group was intermediate between those of the TCM and furosemide groups. These results are compatible with the hypothesis that S-8666 has an additional site of action which is common to that of thiazide diuretics.

Animals↗
PubMed1989

[On the peculiar dentin existing in the gutter-shaped root].

The purpose of this study is to investigate the histological structure of the gutter-shaped root. Materials investigated in this study deal with 15 japanese lower molars of adults having gutter-shaped roots and 2 of them of children. Buccolingual, mesiodistal, and horizontal ground sections of them were prepared and observed with binocular microscopy, polarizing microscopy, phase microscopy, fluorescent microscopy, microradiograph, and scanning electron microscopy. It is thought that the lingual dentin of the gutter-shaped root is transparent and roentgenopaque because it has primarily slender and sparse dentinal tubules. It is considered that the lingual dentin differs from the transparent dentin of which dentinal tubules were secondarily filled with calcified substance. It is considered that the lingual dentin of the gutter-shaped root is thinner than the buccal dentin because the forming time of the lingual dentin isn't brief but the forming speed of it is late. It is thought that the peculiar dentin is formed at the lingual part because one odontoblast shares more broad forming space of the dentin there than the other part.

Adult↗
PubMed1989

[Fine structure of the epithelial cells of the lingual dorsal mucosa in the guinea pig].

The fine structure of the lingual dorsal epithelium of the guinea pig was examined in detail by transmission electron microscopy. In the epithelium of the posterior side of filiform papillae, the surface layer was strongly stained by toluidine blue. This staining pattern is a characteristic feature of hard keratinization. By contrast, in the epithelium on the anterior side of filiform papillae, the surface layer was stained with moderate efficiency by toluidine blue, a characteristic feature of "soft keratinization." The surface area of the interpapillary epithelium was not stained as effectively as these other areas by toluidine blue (Fig. 1). When examined by transmission electron microscopy, cells in the germinal layer of the epithelium on the anterior and posterior sides off iliform papillae and those of the interpapillary epithelium appeared to have an almost identical oval shape. The nuclei of these cells were located in their central areas. In the cytoplasm of these cells, many mitochondria, many free ribosomes, and a few of tonofibrils were seen. Cellular processes were seen to be distributed almost all around each cell. A basal lamina was intercalated between the basal cells of the epithelium and the underlying connective tissue (Fig. 2). In the intermediate layers between the germinal layer and the surface layer of the epithelium, a large number of ketatohyaline granules was observed on the anterior side of filiform papillae. In the deep intermediate layer, mitochondria, kertohyaline granules and free ribosomes were abundant, although the keratohyaline granules were fewer in number and smaller than those in the shallow intermediate layer. Each cell had a rugged surface with spines. The spines of neighbouring cells were linked together by desmosomes (Figs. 3, 4). Both the number and size of the keratohyaline granules tended to increase in the cells of the shallow intermediate layer. Abundant free ribosomes were observed, as was the case in the deep intermediate layer, although the mitochondria were fewer in number than in the deep layers. Relatively flat nuclei were scattered in cells of both the deep and the shallow intermediate layers (Fig. 5). The cells of the surface layer showed a continuous gradation in their composition from that of the cells of the intermediate layer, the major part of their cytoplasm was filled with electron-dense, fibrous structures, and amorphous, moderately electron-dense materials were dispersed between these fibrous structures. A marginal band was located in the contact zone just beneath the cytoplasmic membrane.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

[Kinetic study of cell proliferation in a new wound healing model using tissue cultured corneal endothelial cells].

We studied cell kinetics in the wound healing process using cultured bovine corneal endothelium. We cultured bovine endothelial cells on coverslips coated by hydroxyethyl methacrylate (HEMA) which had on 8 mm HEMA-free zone in diameter, and produced wounds at the center of the monolayer cell sheets using a rotating silicone tip. At various time periods after injury, we added bromodeoxyuridine (BrdU) to the medium and incubated for 12 hours. Then, the specimens with fixed 10% phosphate-buffered formalin and were incubated with a monoclonal antibody against BrdU. The cells incorporating BrdU into DNA were stained by the Avidin Biotin Peroxidase Complex (ABC) method. At 12 hours, no labeled cells were observed. At 24 hours, 14.6 +/- 4.0 cells were stained. The maximum labeling occurred during 48-60 hours after the wound. Seventy two hours after the wound, labeled cells decreased rapidly. Labeled cells were localized within 0.6mm from the wound edge throughout the wound healing process. It can be thought that the wound healing process comprised four phases, i.e., latent, migration, migration plus mitosis, and contact inhibition phases. The first is the latent phase observed during the first six hours after wound infliction. The cells respond to external expansion. The second phase in the migration phase which is last until 24 hours after wound infliction, and occurs mainly through cellular migration, while proliferation has only a minor contribution in this phase. The third is the migration plus mitosis phase. The cell proliferation shows a rapid increase after 72 hours after wound infliction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗