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Biomedical subjects

M Yanagihara

Publications and source records attributed to M Yanagihara.

At least 37 records · Page 2Linked to original sources

Functional morphology of lesions of psoriasis vulgaris transplanted into nude mice at an early stage.

We examined the growth and differentiation of transplanted psoriatic skin in nude mice at an early stage. Psoriatic lesions from three patients were biopsied. Each biopsied specimen was cut into five blocks, which were individually transplanted to nude mice by the embedding method. Two weeks later, growth and differentiation of transplanted specimens were examined by bromodeoxyuridine (BrdU) labelling method and by electron microscopy. Electron microscopically, basal cells were longitudinally high, and the cellular processes were elongated. Basal laminae were multilayered. In the cytoplasm of the basal cells, many mitochondria, endoplasmic reticula, and ribosomes were seen, and tonofibrillar formation was poor. In cell groups in the upper parts of these lesions, both nuclei and cytoplasm showed degeneration. Psoriatic skin transplanted to nude mice exhibited newly formed psoriatic skin and initial epidermal necrosis. The BrdU labelling method labelled cells scattered in the lower part of the epidermis. Psoriatic skin transplanted to nude mice resembled that before transplantation in both ultrastructural findings and growth pattern.

Animals↗

Coriolis effects are principally caused by gyroscopic angular acceleration.

A cause of nausea evoked by cross-coupled rotation (termed Coriolis stimulus) was determined. Subjects were provided with two types of cross-coupled rotations: neck-forward flexion (Neck Flx) and upper body-forward flexion (Body Flx) during horizontal whole body rotation at a constant angular velocity. These Coriolis stimuli were given alternatively in an experimental sequence, and the severity of the nausea they evoked was compared by the subjects. The results indicated that the same quality of nausea was evoked by a slightly higher angular velocity during Body Flx (100.5 degrees/s) than during Neck Flx (90 degrees/s). While Body Flx generated Coriolis linear acceleration several times larger than Neck Flx, both the stimuli generated a similar magnitude of gyroscopic angular acceleration in this condition. Therefore, it was inferred that the nausea evoked by a Coriolis stimulus is principally caused by gyroscopic angular acceleration.

Acceleration↗

A case of superficial spreading melanoma in situ 2.5 mm in diameter.

A 60-year-old woman with superficial spreading melanoma in situ, measuring 2.5 mm in diameter, was examined. She had noticed a very small pigmented lesion 1.2 mm in diameter on her left lower leg in April of 1989. By April of 1990, it had grown to 2.5 mm in diameter. Its edge was irregular, and its color was variegated black to brown. Skin surface markings had disappeared in the center portion. Histopathologically, the lesion was asymmetrical. Atypical large cells nested in the lower epidermis and were scattered singly in the mid and upper epidermis, as seen in Paget's disease. At the periphery of the lesion, single large tumor cells were scattered in the mid epidermis. The tumor cells reacted to monoclonal anti-melanoma antibody HMB-45.

Cell Nucleus↗

Vimentin expression in sweat gland tumours.

Immunohistochemical localization of vimentin was studied in 93 cases of sweat gland tumours using a monoclonal anti-vimentin antibody. A strong immunoreactivity of vimentin was observed in modified myoepithelial or neoplastic myoepithelial cells of mixed tumour of the skin, syringoma, and sweat gland adenoma. Tumour cells in outer layers of tubular, ductal, and duct-like structures usually showed positive staining for vimentin, which coincided with modified myoepithelial cells. All tumour cells of clear cell hydroadenoma showed positive vimentin staining. Tumour cells of the luminal border of tubulo-ductal structures of mixed tumours were rarely immunoreactive for vimentin. Positive vimentin staining of tumour cells in the outer zone of tubulo-ductal structures in sweat gland tumours may be related to reactive proliferation of modified myoepithelial cells and simultaneous growth of luminal tumour cells.

Adenoma↗

Immunohistochemical study of human eccrine sweat ducts with anti-keratin antibodies. Presence of a layer between luminal and peripheral cell layers.

It is known that human eccrine sweat ducts are composed of luminal cells and peripheral cells. In this study, the immunohistochemical staining properties of human eccrine sweat ducts were investigated using seven different anti-keratin antibodies by light microscopy. Anti-keratin antibody MA904, which reacts with 68-kDa keratin peptide specifically stained an intermediate cell layer between the luminal cell layer and the peripheral cell layer in the ducts. Anti-keratin antibody CK8,60 stained both the luminal cell layer and the intermediate cell layer. Anti-keratin antibody MA903 stained all of the layers. Anti-keratin antibodies CK4.26, PKK1, and MAK-6 weakly to faintly stained the luminal cells. Anti-keratin antibody PKK3 stained no cells in the ducts. These results suggest that each cell layer has its own characteristic staining pattern with anti-keratin antibodies. Moreover, the presence of an intermediate cell layer was confirmed by immunoelectron microscopy using anti-keratin antibody MA904.

Eccrine Glands↗

Antidromic activation of vagal and sympathetic afferents does not produce intestinal contractions in dogs.

The question has been asked whether vagal and sympathetic afferents activated antidromically play a role as motor nerves on the in vivo small intestine in dogs anesthetized with urethane. The vagus nerve of one side was cut above the nodose ganglion and the efferent fibers allowed to degenerate. Peripheral stimulation (5-50 Hz, 0.5-3 ms, 5-25 V) of an intact cervical vagus, being able to excite both efferent and afferent fibers, caused large contractions in the jejunum and stomach, whereas stimulation of the contralateral cut cervical vagus could not produce any response in the jejunum but small contractions in the stomach. Peripheral stimulation of the cut cervical vagus did not produce bradycardia and hypotension. Single- and multi-unit discharges to distension of the jejunal segments could be recorded from the peripheral cut end of the cut cervical vagus. Immunohistochemically, there were many substance P-containing cells in both nodose ganglia. Antidromic stimulation of the dorsal roots (T7-T10) did not induce any response in the jejunum but contractions in the stomach. The results may confirm that vagal and sympathetic afferents have no antidromic motor function at least in the in vivo canine small intestine.

Action Potentials↗

Morphological changes of astroglia in the cerebellar cortex of developing mice after neonatal administration of cytosine arabinoside.

Neonatal administration of cytosine arabinoside (Ara-C) induced marked hypoplasia of the mouse cerebellum. In 17-20-day-old mice with neonatal Ara-C injections, the external granular layer was still preserved as an irregular cell laminae in the superficial part of the cerebellum, in contrast to its complete disappearance in normal animals at these stages. Immunohistochemical examination using anti-glial fibrillary acidic protein and monoclonal antibody-1D11 (Ono et al: Dev. Brain Res., 50:154-159, 1989) demonstrated malformation of a palisade-like arrangement of labeled glial fibers in the superficial part of the Ara-C treated mouse cerebellum. Furthermore, the immunoreactive astroglia were observed just beneath the pial membrane and their processes were oriented to the deeper part of the molecular layer.

Animals↗

Brainstem afferents to the intralaminar nuclei of the cat thalamus studied by the horseradish peroxidase method.

Brainstem afferents to the intralaminar thalamic nuclei of the cat have been studied by retrograde axonal transport of horseradish peroxidase (HRP) or wheat germ agglutinin conjugated to HRP (WGA-HRP). Injections of HRP or WGA-HRP into the lateral central and paracentral nuclei led to labeling of cells in various diencephalic structures of the injected side. Some cells were labeled in the intralaminar and medial pulvinar nuclei. A large number of labeled cells were detected in the thalamic reticular and ventral lateral geniculate nuclei. The zona incerta and field of Forel contained a few labeled cells. Occasional labeled cells were seen in the dorsomedial, ventromedial, posterior and lateral hypothalamic nuclei. Labeling of cells in the more caudal brainstem structures was found bilaterally, mostly with ipsilateral predominance. Some labeled cells were detected in the pretectal nuclei, the periaductal gray and the pars reticulata of the substantia nigra as well. The nuclei of Darkschewitsch and Cajal contained occasional labeled cells. Numerous cells were labeled in the superior colliculus, mainly in layers 3 and 4. A number of labeled cells were distributed in almost the entire extent of the brainstem reticular formation. It should be mentioned that the gigantocellular reticular nucleus contained labeled cells bilaterally with contralateral predominance. Very few labeled cells were encountered in the ipsilateral dorsal tegmental and parabrachial nuclei. A few cells were labeled in the vestibular nuclei and nucleus prepositus hypoglossi bilaterally. Some labeled cells were detected mainly contralaterally in three cerebellar nuclei; the fastigial, the interposed and the dentate. Injections of WGA-HRP into the medial central nucleus showed a different pattern of labeling. It is noteworthy that no labeled cells were found in the dorsal thalamus, the hypothalamus (except for the lateral mamillary nucleus), the superior colliculus or the cerebellar nuclei.

Animals↗

Monoclonal antibody that binds to both the prenatal and postnatal astroglia in rodent cerebellum.

A monoclonal antibody (MAb), generated by immunizing mice with homogenized guinea pig cerebellum, labeled cerebellar astroglia including perikarya, radial fibers and veil-like processes in adult rats, mice and guinea pigs. Cell bodies and processes of the immature radial glia in the ventricular neuroepithelium of fetal mice cerebellum were definitely stained by the MAb on the 14th day of gestation. The astroglial components continued to show selective immunoreactivity to the MAb after the 14th day of gestation.

Animals↗

Substance P-like immunoreactive projection to the hippocampal formation from the posterior hypothalamus in the cat.

Following the injection of the fluorescent tracer, 4',6-diamidino-2-phenylindol-2HCl (DAPI) or Fluoro-Gold (FG), into the hippocampal formation of the cat, retrogradely-labeled cells were seen mainly in the supramammillary nucleus and the posterior hypothalamic area. Some of these labeled cells contain substance P-like immunoreactivity (SP-LI). When wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) was injected into the supramammillary nucleus and its adjacent regions, anterogradely-labeled terminals were detected, for the most part, in the granular layer and the supragranular molecular layer of the dentate gyrus as well as in the pyramidal layers of the hippocampus and subiculum. All of these layers were included within the terminal areas containing the SP-like immunoreactivity.

Animals↗

Immunohistochemical staining properties of amyloids with anti-keratin antibodies using formalin-fixed, paraffin-embedded sections.

Immunohistochemical staining properties of amyloids with anti-keratin antibodies were investigated using an avidin-biotin-peroxidase complex (ABC) system on formalin-fixed, paraffin-embedded sections. Anti-keratin antibody EAB-903 which recognize 66K and 57K daltons keratin peptides reacted with amyloid deposits in both lichen amyloidosus (LA) and macular amyloidosis (MA), but did not react with either primary systemic amyloidosis (AL), secondary systemic amyloidosis (AA) or heredofamilial amyloid polyneuropathy (AF). However, anti-keratin antibodies EAB-904 and MAK-6 did not react with any types of amyloids. These results suggested that immunohistochemical staining with anti-keratin antibody EAB-903 using formalin-fixed, paraffin-embedded sections appeared to be a useful method in making differential diagnosis of primary localized cutaneous amyloidosis (AD).

Amyloid↗

Papillomavirus antigen in the epidermoid cyst of the sole. Immunohistochemical and ultrastructural study.

An epidermoid cyst of the sole was studied immunohistochemically and ultrastructurally. Papillomavirus particles were present in the horny layer and in the upper layers of the epidermis of the cyst and within the acrosyringeal epithelium overlying the cyst. Thickened basal lamina-like structures similar to those found in the eccrine sweat duct tumors such as in cylindroma and eccrine spiroadenoma existed at the epidermal-dermal junction of the cyst wall. Carcinoembryonic antigen was immunohistochemically demonstrated in the center of the epidermoid cyst and the DAB reaction products took the shape of a circle resembling that of the sweat ducts in the horny layer.

Adult↗

Thalamic projections to the hippocampal and entorhinal areas in the cat.

The thalamic projections to the hippocampal formation and to the subicular and entorhinal areas in the cat have been studied with retrograde transport of horseradish peroxidase (HRP) or wheat germ agglutinin conjugated to HRP (WGA-HRP) and anterograde transport of WGA-HRP. Retrograde transport tracers injected in various parts of these cortices resulted in labeled cells in the midline, anterior, and lateral dorsal nuclei. Injections into the hippocampal formation or the subiculum led to retrograde labeling of cells in the reuniens nucleus of the ipsilateral thalamus throughout its rostrocaudal extent, whereas the restricted injections into the dentate gyrus and the inferior region of the hippocampus led to no labeling. Following an injection into the pre- and parasubiculum, a large number of labeled cells were seen not only in the reuniens nucleus but in other midline nuclei. In addition, a substantial number of labeled cells were also detected in the anterior and lateral dorsal nuclei, particularly in the anterodorsal nucleus, which contained densely arranged labeled cells throughout almost the entire rostrocaudal extent. An injection into the medial entorhinal area labeled a number of cells in the anterior nuclei and in the reuniens nucleus, particularly its dorsal part. Injections into various subdivisions of the lateral entorhinal area yielded different patterns of distribution of labeled cells in the thalamic nuclei. An injection into the ventromedial division (VMEA) led to abundant labeling of cells in the paraventricular and reuniens nuclei. After an injection into the ventral division (VLEA), numerous labeled cells were detected in the reuniens nucleus and a lesser number in the paraventricular nucleus at anterior levels. When an injection was made into the dorsal division (DLEA), a large number of labeled cells were detected in the reuniens nucleus, and less numerous labeled cells were found in the central medial nucleus. There appears to be a topographic arrangement of cortical projections of the reuniens nucleus. The pre- and parasubiculum receive projections from the most medial part of the reuniens nucleus near the midline, and the DLEA receives projections from the medial part of the nucleus. The cells projecting to the VLEA and MEA are distributed in the central part of the reuniens nucleus, and those to the VMEA are distributed in the lateral part. Anterograde experiments were also performed; injections of WGA-HRP into the reuniens nucleus resulted in terminal labeling in the superficial layers of the subicular area and the neighboring hippocampus and in the entorhinal area.

Afferent Pathways↗