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T Inoué

Publications and source records attributed to T Inoué.

At least 19 recordsLinked to original sources
PubMed2001

Scanning electron-microscopic view of the oral and basal epithelial surfaces of the rat soft palate.

We studied corresponding structures on the oral and basal surfaces of the oral epithelial layer, focusing on the microanatomy of gustatory papillae. Specimens for scanning electron microscopy were obtained from the rat soft palates and fixed with a mixture of 2% paraformaldehyde and 1% glutaraldehyde. They were first prepared without postfixation and conductive-staining to study the oral surface. After examination, the epithelium was reinforced by additional sputter coating and treated with 6 N NaOH at 60 degrees C to exfoliate the basal epithelial surfaces without any significant artifacts. The papillae, showing circular, elliptical or fusiform protuberances on the oral surface, were classified into two types: types I and II. The type I and type II papillae contained one and two taste pores, respectively. On the basal epithelial surface, the basal portions of the taste buds were associated with concentrically arranged nerve fibers and Schwann cells. Another characteristic finding on the basal epithelial surface was the presence of excretory ducts of minor salivary glands in a close spatial relationship to taste buds. It is suggested that saliva coming out through the duct is mixed with food, thus enabling intimate contact with the taste pores of the papillae.

Animals↗
PubMed2000

Intercellular junctions between palisade nerve endings and outer root sheath cells of rat vellus hairs.

Hair follicles have a longitudinal set of sensory nerve endings called palisade nerve endings (PN). We examined the junctional structures between the PN and outer root sheath (ORS) cells of hair follicles in the rat external ear. Transmission electron microscopy of serial thin sections showed that the processes of the ORS cells penetrated the basal lamina of the hair follicle, forming intercellular junctions with the PN (PN-ORS junctions). Two types of junctions were found: junctions between nerve endings and ORS cells (N-ORS junctions) and those between Schwann cell processes and ORS cells (S-ORS junctions). The N-ORS junctions had two subtypes: 1) a short process or small eminence of the ORS cell was attached to the nerve ending (type I); or 2) a process of the ORS cell was invaginated into the nerve ending (type II). The S-ORS junctions also had two subtypes: 1) a short process or small eminence of the ORS cell was abutted on the Schwann cell process (type I); or 2) a process of the ORS cell was invaginated into the Schwann cell process (type II). Vesicles, coated pits, coated vesicles, and endosomes were sometimes seen in nerve endings, Schwann cells, and ORS cells near the junctions. Computer-aided reconstruction of the serial thin sections displayed the three-dimensional structure of these junctions. These results suggested that the PN-ORS junctions provided direct relationships between the PN and ORS in at least four different patterns. The discovery of these junctions shows the PN-ORS relationship to be closer than previously realized. We speculate that these junctions may have roles in attachment of the PN to the ORS, contributing to increases in the sensitivity of the PN, and in chemical signaling between the PN and ORS.

Animals↗
PubMed1999

Scanning electron microscopic observation on the equatorial region of the rat intrafusal muscle fibres, especially on the subsarcolemmal sarcoplasmic reticulum.

We examined intracellular structures in the equatorial region of the muscle spindles of rat soleus muscles by scanning electron microscopy, paying particular attention to the ultrastructure of the sarcoplasmic reticulum (SR) beneath the sarcolemma. The subsarcolemmal SR was more developed in nuclear chain fibres than in nuclear bag fibres as was reported in the sleeve and extracapsular regions. In addition, the subsarcolemmal SR of the chain fibre formed a fenestrated sheet, whereas that of the bag fibre organized a layer of fenestrated bands beneath the sarcolemma where the sensory nerve endings are associated. No T-tubules were discerned in the subsarcolemmal SR of both fibres, which may be concerned with the little contraction of the equatorial region.

Animals↗
PubMed1999

Three-dimensional structure of the synaptic contact of the neuromuscular junction in the rat lumbrical muscle.

This study examined the three-dimensional structures of the synaptic contact in rat lumbrical muscles by scanning electron microscopy using three different methods: the aldehyde prefix-osmium-dimethyl sulfoxide-osmium method (A-O-D-O method), the cell-extraction method, and the NaOH-digestion method. These three methods visualized the motor nerve endings, subneural basal lamina and postsynaptic sarcolemma, respectively. The motor nerve endings were composed of a cluster of spherical and cylindrical terminals. Pores on the presynaptic membrane were considered openings of exocytotic vesicles. The postsynaptic side of the subneural basal lamina showed numerous ridges, corresponding to junctional folds. Most of the ridges rose vertically from their base. The ridges showed widening, narrowing, and branching. The subneural basal lamina appeared to be composed of small granular substances. The basal lamina of the primary synaptic clefts had pores 25-30 nm in diameter, which may facilitate the transport of acetylcholine (ACh) without being hydrolyzed by ACh esterase in the lamina. On the outer surface of the postsynaptic sarcolemma in a sole plate, the primary synaptic clefts were composed of a mixture of depressions and gutters; so far as we know, this represents the only example of such a phenomenon. These depressions and gutters seem to fit respectively into the spherical and cylindrical terminals of the motor nerve endings. The openings of the junctional folds consisted of a mixture of many slits and a few pits in the primary synaptic clefts.

Animals↗
PubMed1999

Three-dimensional architecture of the keratin filaments in epithelial cells surrounding taste buds in the rat circumvallate papilla.

The three-dimensional architectures of the perigemmal cells and their keratin bundles in the rat circumvallate papillae were studied by transmission and scanning electron microscopy. The perigemmal cells were classified into three layers: basal, middle and upper. The basal layer consisted of polygonal cells located close to the basal lamina, the middle layer comprised longitudinally elongated cells fitting the lateral convexity of the taste bud, and the upper layer was imbricating flat cells along the upper portion of the taste bud. When fresh specimens were jointly treated with Triton X-100 and sonication, the taste buds were often detached and the cytoplasmic matrices of the perigemmal cells were effectively removed. Consequently, we were able to demonstrate an extensive network of the subplasmalemmal keratin bundles of the perigemmal cells. The framework appeared either as a thin lacework, a thick fence-like structure, or a lattice work in the basal, middle, and upper layers, respectively. The thin lacework in the basal layer was considered to be a developing process of the framework. The thick fence-like structure in the middle layer probably plays a primary role in supporting the taste bud. The latticework in the upper layer is believed to reflect a remodeling in reducing the keratin framework.

Animals↗
PubMed1999

[Scanning electron microscopic studies of the basal surface of the corneal endothelium and the stromal and endothelial surfaces of Descemet's membrane in rats].

PURPOSE: The basal surface of the corneal endothelium and the stromal and endothelial surfaces of Descement's membrane in rats were studied by scanning electron microscopy. METHODS: We compared the fine structures of the two surfaces of Descemet's membrane both after sputter-coating with platinum and without sputter-coating. RESULTS: Fine structures were made clearly visible without metal coating by heating specimens to 300 degrees C during observation. On the basal surface of th endothelium, pinocytotic vesicles and invagination of the basal cell membrane were visible. After sputter-coating, Descemet's membrane appeared to be composed of granular substances. The size of the granules was larger on the stromal side than on the endothelial side. Descemet's membrane observed without sputter-coating was composed of fine fibrous structures, showing a felt-like appearance on both stromal and endothelial sides. The diameter of the fibers on the stromal surface was thicker than on the endothelial side. CONCLUSION: These results may indicate a characteristic difference between the collagen types existing on the two sides of Descemet's membrane.

Animals↗
PubMed1998

Ultrastructural changes of the myoepithelium of the dilator pupillae during miosis and mydriasis in the rat iris.

Changes in the three-dimensional structures of the myoepithelium of the dilator pupillae (MDP) during mydriasis and miosis were investigated in the rat by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Following fixation, SEM specimens were treated with sodium hydroxide to expose the muscle surface. Significant morphological differences were noted in the anterior surface of the MDP between mydriasis and miosis. In the mydriatic eye, a highly rugged structure with numerous linear folds was oriented circularly or obliquely together with spherical bulges. These structures, presumably corresponding to the highly contractile portion of the myoepithelial cells, were more prominent near the pupillary margin than near the ciliary margin, indicating that the MDP may contract much more strongly in the pupillary margin. In the miotic eye, the anterior surface of the MDP showed less conspicuous linear folds in the pupillary area, and was almost flat in the ciliary area. Radially oriented ridges were observed only in the pupillary area. These findings suggest that the contraction of the sphincter pupillae in miosis induces a stretching of the MDP toward the pupil and a circular shrinkage of the MDP. Ultrastructural changes of the MDP particularly near the pupillary margin may play an important role in regulation of the pupil diameter as a diaphragm of the eye because morphological changes such as the linear folds, spherical bulges, and ridges were more prominent near the pupillary margin than those near the ciliary margin.

Animals↗
PubMed1996

Scanning electron microscopy of the basal surface of the epidermis of human digits.

The epidermal-dermal junction of the volar skin of human digits was examined by scanning electron microscopy (SEM). Fixed specimens obtained from cadavers were treated with 6 N NaOH to exfoliate the epithelium. The three-dimensional features of the basal surfaces were clearly visualized by SEM. Epithelial prolongations (intermediate and limiting ridges) protruded towards the dermis, and transverse ridges were visible between them. Nerve fibers and Schwann cells were aggregated around the sweat ducts on the intermediate ridges. Discoid structures were visible among the nerve fibers and Schwann cells. Examination by transmission electron microscopy of ultrathin sections of re-embedded specimens confirmed that the discoid structures were nerve endings that covered the Merkel cells. Minute projections were studded on the basal surfaces of basal keratinocytes. The projections in the intermediate ridges appeared to be villous, whereas the profiles of those in the limiting ridges resembled cobblestones. This morphological difference might be a reflection of function.

Aged↗
PubMed1993

A simple method of chromium coating using a ferrotype plate for scanning electron microscopy.

A simple method of chromium coating was developed. A chromium ferrotype plate for drying photoprints was used as a target of a planar magnetron ion-sputter coater. As a result, a high quality chromium film was obtained on dried specimens at room temperature without cooling. The grain size, measuring 1-2 nm in diameter, was small enough for observations of ultrastructures such as F1 particles on the inner mitochondrial membrane. In routine studies under x 100,000, however, chromium coating was not recommended because of its low emission of secondary electrons.

Chromium↗
PubMed1992

The interface between epithelium and lamina propria in the rat urinary bladder.

We investigated by transmission and scanning election microscopy the interface between the epithelium and lamina propria in the rat urinary bladder. A digestion technique that dissolves the basal laminae and collagen fibrils was effective in cleaving the mucosa at this level; the specimens were then prepared for scanning electron microscopy, thus visualizing the basal epithelial surface and the uppermost surface of the lamina propria. The underside of the epithelium is scored by very numerous grooves which in the intact organ are occupied by a dense network of blood capillaries. These vascular grooves allow a large number of capillaries (epithelial capillaries) to run at a distance of a few tenths of a micron from the epithelium. On the side of the lamina propria, after collagen and other extracellular materials had been removed, the capillary network itself is visible in the uppermost region. The network is complementary to that of vascular grooves. Other smaller grooves on the basal surface of the epithelium correspond to nerve fibres which run within a few tenths of a micron from the epithelium.

Animals↗
PubMed1992

Complementary scanning electron microscopy: technical notes and applications.

This report introduces practical techniques and applications of complementary scanning electron microscopy (SEM). To identify the complementary structures at high magnification, we first made a montage pair of low magnification micrographs as a guide map. Consulting the map, we took complementary micrographs at high magnification. When taking a picture at high magnification, we drew the outline of the most prominent structures on a transparent plastic plate attached to the cathode-ray tube of a SEM. Then another picture of the complementary structures was taken after adjusting the complementary structures to the reverse image of the plastic plate. We performed three applications of the complementary SEM: 1) complementary observation of the epithelial underside and lamina propria of the rat urinary bladder; 2) complementary observation of the fractured Golgi apparatus; and 3) evaluation of specimen drying methods. After proper digestion of the rat urinary bladder using strong alkali, the epithelium was detached from the underlying lamina propria. On the basal side of the epithelium, the meshwork of grooves were visible. The observation of the corresponding lamina propria confirmed that the grooves were occupied by blood capillaries located in the uppermost part of the lamina propria. The complementary observation of the Golgi apparatus was useful for understanding its three-dimensional architecture. The observation on both complementary fractured surfaces of the Golgi apparatus from the mouse lacrimal gland demonstrated the continuity of the Golgi stacks. It was also effective for observing both the cis and trans side of the same Golgi stack. Complementary SEM was also useful for evaluating the specimen drying method.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Scanning electron microscopic observations on muscle cells of experimental mitochondrial myopathy produced by 2, 4-dinitrophenol.

The morphological changes of the skeletal muscle cells of the rat experimental myopathy induced by 2, 4-dinitrophenol were examined by scanning electron microscopy in comparison with the ultrastructure of normal muscle cells. Specimens were prepared by the Aldehyde-Osmium-DMSO-Osmium method which permits the three-dimensional demonstration of intracellular structures under SEM. In the specimen prepared by the method, myofibrils having been completely dissolved, intracellular membranous structures such as the sarcoplasmic reticulum, T-tubules and mitochondria were clearly demonstrated in three dimensions. In the experimental mitochondrial myopathy, large accumulations of mitochondria were observed at the subsarcolemmal region. Mitochondria in the perinuclear and intermyofibrillar region showed swelling and occasionally accompanied abnormal concentric cristae. The sarcoplasmic reticulum which showed regular network in normal muscle cells entirely disappeared in the mitochondrial myopathy. Although the mitochondrial changes obtained in this study were almost identical to those previously reported by transmission electron microscopy, the changes in the sarcoplasmic reticulum have not been described in previous works.

2,4-Dinitrophenol↗
PubMed1989

High-resolution low-temperature scanning electron microscopy for observing intracellular structures of quick frozen biological specimens.

Intracellular structures of rapidly frozen biological tissues were observed in 3-D under a low-temperature scanning electron microscope using a newly developed side-entry type cryo-holder. The present low-temperature SEM is simple, easy to operate and effective for observing biological materials at high magnification. Biological tissues (the pancreas, small intestine, brown adipose tissue and Harderian gland) freshly removed from the mouse were immediately frozen in liquid propane cooled with liquid nitrogen, and their surfaces were manually fractured using a precooled razor blade in liquid nitrogen before introducing the cryo-holder into the SEM. When intracellular structures were revealed after appropriate sublimation, the specimens were coated with gold using a metal evaporator fitted to the side of the microscope column at one of the specimen chamber ports. The cryo-holder was connected to a copper braid coming from a liquid nitrogen reservoir to maintain a low temperature. Using this method, intracellular structures such as the mitochondria and endoplasmic reticulum were demonstrated at high magnifications. Ribosomal granules were discerned on the rough endoplasmic reticulum of the pancreatic acinar cells. Granular substances, presumably elementary particles, were also recognized on the mitochondrial cristae of the brown adipose tissue. The method was particularly effective for studying the 3-D configuration of lipid droplets which had been difficult to preserve by chemical fixation.

Adipose Tissue, Brown↗
PubMed1989

Three-dimensional demonstration of the intracellular structures of mouse mesothelial cells by scanning electron microscopy.

Intracellular structures of mouse mesothelial cells lining the small intestine were studied by scanning electron microscopy. Specimens were prepared by the freeze-polishing method which permitted demonstration of the attenuated thin layered organization of the intracellular structures. When the surface cell membrane had been partially turned over during the specimen preparation procedure, many pinocytotic vesicles were observed attached to the cytoplasmic side of the cell membrane. We also demonstrated the external side of the basal cell membrane on which many openings of the pinocytotic vesicles were clearly shown as those recognized on the free cell surface. Two adjacent pinocytotic vesicles often appeared fused together. The multivesicular vacuole formed by the congregation of the pinocytotic vesicles were sometimes recognized on the cytoplasmic side of the surface and basal cell membrane. On the nuclear surface, nuclear pores and polysomes were visible. From our SEM findings, we classified the rough endoplasmic reticulum into three types: type I, II and III. The type I rough endoplasmic reticulum was composed of flat cisternae with fenestration, the type II of polygonal flat cisternae without fenestration, and the type III of vesicular cisternae. Polysomal formation is evident in the type III, but less in the type I and II. All of the endoplasmic reticulum appeared connected each other forming a continuous system in the cell. Two kinds of the Golgi apparatus were recognized: a stretched type with highly extended Golgi cisternae and a shrunken type with less developed Golgi cisternae. In the latter, lots of Golgi vesicles were attached on the periphery of the cisternae, and the outermost cisterna was commonly fenestrated.

Animals↗
PubMed1989

Distal surface of the rat ruffle-ended ameloblasts at the stage of enamel maturation observed by scanning electron microscopy.

Distal surface of the rat ruffle-ended ameloblasts was observed by high resolution scanning electron microscopy. Specimens fixed by perfusion with 0.5% formaldehyde and 0.5% glutaraldehyde were decalcified with ethylenediamine tetraacetic acid and freeze-fractured using dimethyl sulfoxide. They were treated with 0.1% osmium tetroxide for 96 hr to remove excess cytoplasmic matrices, dehydrated, and critical-point dried. The present method was useful for observing both surface and intracellular structures simultaneously. The dense lamina lining the distal surface of the ruffle-ended ameloblasts having been dissolved in this preparation, the surface was clearly demonstrated in three dimensions under SEM. The surface was characterized by a complex labyrinth formed by protrusion and invagination of the plasma membrane. At high magnification, two kinds of minute granules are visible: small and larger granules measured as 10-20 nm and 70 nm in diameter, respectively. The former were more numerous than the latter. Furthermore, microfibrils connecting the protrusions of the plasma membrane were observed on the distal surface. The small granules probably connect the dense lamina with the distal surface of the ameloblasts. In addition, a denuded area free from the granules was sometimes recognized on the distal surface. These surface structures of the distal end of the ameloblasts appeared to be concerned with the enamel maturation.

Ameloblasts↗
PubMed1988

A new drying method of biological specimens for scanning electron microscopy: the t-butyl alcohol freeze-drying method.

A simple drying method for biological materials for scanning electron microscopy was developed. Fixed specimens were immersed in t-butyl alcohol after dehydration through a graded series of ethanol. When the room temperature fell below the melting point of t-butyl alcohol (25.5 degrees C), liquidized alcohol obtained by warming was used. Specimens in the alcohol were then frozen in a refrigerator. They were placed in the bell jar of a vacuum evaporator and simply evacuated with a rotary pump. The samples were completely dried within 1 h after the frozen alcohol was sublimated in the vacuum. When examined by scanning electron microscopy (SEM), both surface and intracellular structures were demonstrated in three-dimension without any significant drying artifacts. Careful comparison of the results indicated that the SEM images obtained by this method were either superior or equal to those obtained by the critical point drying method.

Animals↗