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  • IPSP  (4)
  • Electron microscopy  (3)
  • Keratinization  (3)
  • Physics  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 282 (1990), S. 402-407 
    ISSN: 1432-069X
    Keywords: Electron microscopy ; Culture ; Hair cells ; Growth ; Differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cultured hair cells from 4-day-old C3H mice were studied by electron microscopy. The hair roots isolated from the skin by collagenase digestion were dispersed into a cell suspension by treatment with a mixture of trypsin and ethylenediaminetetraacetate. The cells were cultured in MCDB-153 (a medium containing seven growth factors) for 1, 3, 6 or 13 days. The number of cultured cells on day 3 was twice that on day 1, and stayed at the same level until day 13. By electron microscopy, some of the cells cultured for 1 day were seen to be undifferentiated and others already showed differentiation into various hair structures. Such differentiated cells disappeared on day 3 and most of the cells cultured for 3 days were undifferentiated. Cells cultured for 6 days were differentiated showing inner root sheath cell, hair cortical cell and medulla cell structures. The characteristics of these cultured cells corresponded well to those of in vivo cells of the hair tissues from the back skin of 7-day-old C3H mice. On day 13 degeneration occurred in the cultured cells. In none of these cultures were mesenchymal cells, such as fibroblasts, found. The present electron microscopic study reveals that immature cells obtained from mouse hair tissues proliferate in vitro and differentiate into several subpopulations corresponding to those of in vivo cell layers of hair tissues. The present culture technique may be useful for studies of hair cell growth and differentiation.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-069X
    Keywords: Inflammatory linear epidermal naevus ; Keratinization ; DACM ; Involucrin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Skin lesions of three patients with inflammatory linear verrucose epidermal naevus (ILVEN) were examined. Histologically, orthokeratosis and parakeratosis were alternately seen in the acanthotic epidermis. By N-(7-dimethylamino-4-methyl-3-coumarinyl)maleimide staining, the horny cells in the parakeratotic epidermis showed a cytoplasmic SH pattern and a weak membranous SS pattern. The orthokeratotic epidermis revealed an increased involucrin expression, whereas the parakeratotic epidermis showed almost no involucrin expression. Ultrastructurally, in the parakeratotic epidermis, the living keratinocytes had prominent Golgi apparatuses and vesicles in the cytoplasm. In the intercellular spaces in the upper spinous layer through to the lower horny layer, an electron dense, homogeneous substance was deposited. The cytoplasm of the horny cells was filled with keratin filaments and contained remnants of nucleus and cytoplasmic membrane structures, and some lipid droplets. The marginal band formation was incomplete. Most of these ultrastructural abnormalities were not found in the orthokeratotic epidermis. There are both similarities and differences in histopathogenesis of the parakeratotic epidermis between ILVEN and psoriasis. A unique finding was the lack of involucrin expression in the ILVEN parakeratotic epidermis.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 284 (1992), S. 290-296 
    ISSN: 1432-069X
    Keywords: Cepharanthine ; Minoxidil ; Culture ; Hair cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of cepharanthine and minoxidil on proliferation, differentiation and keratinization of cultured cells from the murine hair apparatus were examined electron microscopically. Both cepharanthine and minoxidil stimulated cell proliferation and delayed initiation of differentiation and keratinization of the cultured cells. On day 6, most control cells (87%) cultured in a 0.03 mM calcium medium without cepharanthine and minoxidil were differentiated into several subpopulations corresponding to those of in vivo cell layers of the hair apparatus, while most of the cells cultured with cepharanthine (71%) or minoxidil (70%) were still immature. On day 13, the number of degenerated cells increased (63%) in the control culture, whereas in the culture treated with cepharanthine or minoxidil, cell degeneration scarcely occurred (5% and 8%, respectively). Differentiated cells having tonofilaments were often observed in the cepharanthine- and minoxidil-treated cultures (76% and 72%, respectively). Elevation of extracellular calcium up to 1.0 mM induced keratinization (34%) in the control culture on day 6, while no keratinized cells were observed in the cepharanthine- or minoxidil-treated culture. On day 13 keratinization similarly occurred in the cultures with cepharanthine (30%) or minoxidil (48%). These results show that both cepharanthine and minoxidil may directly influence proliferation, differentiation and keratinization of cultured cells from the hair apparatus.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 279 (1986), S. 112-119 
    ISSN: 1432-069X
    Keywords: Innermost cell layer ; Outer root sheath ; Anagen hair follicle ; Keratinization ; Light and electron microscopes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To investigate cell differentiation in the outer root sheath (ORS) of the human anagen hair follicle, scalp skin specimens from individuals with normal hair were examined using light and electron microscopes. In the bulbar portion, the ORS was composed of two cell layers. The cells in the outer layer gradually increased in number upwards and finally underwent so-called trichilemmal keratinization, which proceeded toward the hair canal. On the other hand, the inner cells in the bulb formed a single cell layer along the outside of Henle's layer during cell differentiation; this unique layer was referred to as the innermost cell (IMC) layer of the ORS. With the use of hematoxylin and eosin stain, at the suprabulbar portion, where Henle's cells were keratinizing, an eosinophilic substance was deposited in the inner (Henle's) side of the IMC cytoplasm. The IMCs gradually became entirely eosinophilic and often produced keratohyaline granules. Ultrastructurally, the IMCs of the ORS showed an oblong shape forming a regularly arranged single-cell layer along the keratinizing Henle's layer and accumulated tonofilaments in the cytoplasm. They produced a few small electron-dense keratohyaline granules and were keratinized at the level at which Henle's layer still preserved its cell structure. From these findings, it is suggested that there are two types of keratinization of the ORS: trichilemmal keratinization and IMC keratinization.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 281 (1989), S. 254-259 
    ISSN: 1432-069X
    Keywords: Innermost cell layer ; Tonofilaments ; Huxley's cells ; Henle's cells ; Anagen hair follicles ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To elucidate the biologic roles and further cytologic characteristics of the innermost cell (IMC) layer of the outer root sheath (ORS), human anagen hair follicles were ultrastructurally examined. In the lower follicle, the transeversely running tonofilaments in the inner side of the cytoplasm of the IMCs showed a massive accumulation, facing the keratinized part of a Huxley's cell protruding through a Henle's pore. In a rare instance, a spindle-shaped cell was seen between the IMC layer and the keratinized Henle's layer. At the lower isthmus portion, some of the IMCs containing a large number of tonofilaments showed a partial degeneration of the inner side of the cytoplasm. More distally, intercellular spaces between the keratinized IMCs and keratinized Henle's cells were partly dilated and contained amorphous substances. It is suggested that the IMCs in the lower follicle may play a role to support and cover the inner hair structures, tightly as hoops of a barrel. In the isthmus portion, the IMCs may loosely support and guide the keratinized Henle's cells undergoing degeneration.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 283 (1991), S. 141-148 
    ISSN: 1432-069X
    Keywords: Sjögren ; Larsson syndrome ; Ichthyosis ; Ultrastructure ; Lamellar body ; Keratinization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ichthyosiform skin and the uninvolved skin of a 5-year-old Japanese female with Sjögren — Larsson syndrome were examined by light and electron microscopy to elucidate the keratinization disorder. Light microscopically, the epidermis of the ichthyosiform skin showed acanthosis, papillomatosis and hyperkeratosis. The horny cells had a basket-weave appearance. The granular cell layer was slightly thickened. Slight round cell infiltration and vascular dilatation were seen in the upper dermis. The uninvolved skin was histologically normal. Electron microscopically, in both ichthyosiform and uninolved skin, abnormal lamellar or membranous inclusions were present in the cytoplasm of horny cells of the epidermis. These inclusions appeared to be derived from some of the lamellar bodies and/or abnormal membranous structures found in the cytoplasm of spinous and granular cells. Mitochondria in the epidermal basal cells were more numerous in the ichthyosiform skin than in the uninvolved skin. These findings indicate that, whether the skin is involved or not, the epidermis of the patient with this disorder may always have a structural abnormality, which may be genetically determined. Local environmental factors may play a role in inducing the acanthosis and papillomatosis of the epidermis.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 7 (1969), S. 214-230 
    ISSN: 1432-1106
    Keywords: Deiters ; Vestibular nerve ; EPSP ; Monosynaptic ; Disynaptic ; IPSP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stimulation of the vestibular nerve induced EPSPs monosynaptically in 29% of cat's Deiters neurones sampled on the ipsilateral side. These EPSPs started with latencies of 0.6–1.0 msec, rose sharply with a summit time of 0.5 msec and decayed exponentially with a time constant of 0.9–1.7 msec. Then amplitudes were graded finely according to the intensity of the vestibular nerve stimulation, the maximal size being 5–10 mV. The unitary EPSPs, evoked by vestibular nerve stimulation at juxta-threshold intensity or appearing spontaneously, were as small as 0.2–0.3 mV in amplitude. Those neurones monosynaptically activated by vestibular nerve volleys were located in the ventral portion of the nucleus of Deiters, in agreement with histological data. The vestibular nerve impulses also produced delayed EPSPs with latencies of 1.0–1.8 msec, presumably disynaptically. They occurred in many Deiters neurones located not only ventrally but also dorsally. Even later EPSPs often were superposed on the monosynaptic EPSPs with latencies of 1.9–2.2 msec. There is evidence that they were caused by repetitive discharges in the vestibular nerve fibres which occur in response to single shock stimulation of the vestibular nerve. IPSPs were produced only polysynaptically in some Deiters neurones in association with the monosynaptic EPSPs.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 12 (1971), S. 223-237 
    ISSN: 1432-1106
    Keywords: Deiters ; Purkinje Cell ; Mossy fibre ; Granule Cell ; IPSP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In anaesthetized cats, electric pulse stimuli were applied at various lateralities to the anterior lobe of the cerebellum. In dorsal Deiters neurones delayed IPSPs with latencies of 3–6 msec were evoked from the entire area of the culmen including the paravermis bilaterally. The delayed IPSPs had a summit time of about 2 msec and a duration of about 7 msec. They showed a marked temporal facilitation and subsequent depression with double shock stimulation. Corticovestibular fibers were penetrated within the nucleus of Deiters and showed delayed, labile responses to cortical stimulation, corresponding to the delayed IPSPs in Deiters neurones. During stimulation of the anterior lobe at any laterality, field potentials recorded in the cerebellar cortex further revealed that there was activation, presumably through axon collaterals of mossy fibers, of granule cells and subsequently of Purkinje cells in the vermal cortex. Cortical events exhibited a prominent temporal facilitation and subsequent depression, in parallel with that observed for the delayed IPSPs in Deiters neurones. The delayed IPSPs in Deiters neurones arising from a wide area of the cerebellar cortex thus were attributed to activation through mossy fiber-granule cell pathway of Purkinje cells of the corticovestibular projection.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 2 (1966), S. 330-349 
    ISSN: 1432-1106
    Keywords: Deiters neurones ; IPSP ; Monosynaptic ; Purkinje cells ; Inhibitory neurones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary During stimulation of the anterior lobe of the cerebellum, postsynaptic potentials were recorded intracellularly from ipsilateral Deiters neurones of the cat. In the majority of examined cells, the inhibitory postsynapic potentials were induced with short latency; 1.06 msec on the average from lobule III or IV. The latency was longer (1.23 msec) when the lobule V was stimulated, while it was shorter (0.86 msec) from the juxtafastigial region. It follows that the IPSP was produced via a monosynaptic pathway at a conduction velocity of 15 to 20 m/sec. Recording of the extracellular field potentials and focal stimulation within and around Deiters' nucleus further indicated that the inhibitory impulses propagated out of the cerebellum along a remarkable bundle of fibres which terminated within Deiters' nucleus. These results are all explicable by assuming that the cerebellar Purkinje cells are inhibitory in nature and so produce IPSPs monosynaptically in Deiters neurones via the long corticofugal fibres. Monosynaptic EPSPs were also detected in some Deiters neurones. They are considered to be mediated by the other pathways formed of axon collaterals of the cerebellar afferents.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 8 (1969), S. 190-200 
    ISSN: 1432-1106
    Keywords: Vestibular ; EPSP ; IPSP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neurones in the descending, medial and superior vestibular nuclei of the cats were explored with intracellular microelectrodes. Cerebellar- and spinal-projecting neurones were identified by their antidromic invasion from the region of fastigial nuclei and from the second cervical segment, respectively, and the others by their location. The central actions of the primary vestibular impulses upon these non-Deiters vestibular nuclei neurones were investigated by using electric stimulation of the ipsilateral vestibular nerve. Many of these cells received excitatory postsynaptic potentials (EPSPs) monosynaptically, similar to those evoked in the ventral Deiters neurones, as described elsewhere, except that the unitary EPSPs are often larger. Some cells received only polysynaptic EPSPs or IPSPs and a few cells were not influenced at all.
    Type of Medium: Electronic Resource
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