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  • Deiters neurones  (6)
  • Ultrastructure  (5)
  • Physics  (3)
  • Adaptation  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 280 (1988), S. 308-318 
    ISSN: 1432-069X
    Keywords: Pili annulati ; Ultrastructure ; DACM staining ; Hair cortex ; Protein metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Plucked scalp hairs and hair roots of pili annulati were examined to understand their pathogenesis. Stereoscopic examinations of hairs in transmitted light and/or reflected light and light microscopic surveys of the cross-sections of hairs confirmed that the cortical empty spaces appeared to be responsible to the unique dotted shiny appearance of the hairs seen by the unaided eyes under a refracted light. By transmission electron microscope, small vacuoles and dense bodies were observed in the cytoplasm of the differentiating cortical cells; subsequently, with increasing number of tonofilaments, an uneven distribution of free ribosomes occurred and abnormal spaces containing fine granular substances were formed in the cytoplasm of the cortical cells. Occasionally, extremely large cortical trichohyaline granules were found. In the keratinized hair, irregular empty spaces were present in the cortex of the abnormal hair segments. Histochemically, the keratinized cortex of the affected hairs always had more residual SH groups than the controls. Pili annulati may be a disorder of protein metabolism involving a partial dysfunction of cytoplasmic ribosomes, resulting in a lack of cortical keratin formation.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 284 (1992), S. 95-99 
    ISSN: 1432-069X
    Keywords: Chromoblastomycosis ; Host-fungus relationship ; Morphometry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To investigate the histological distribution and the morphology of the fungi and the tissue reactions in chromoblastomycosis, especially in the process of trans-epidermal elimination, cutaneous lesions of two patients with this disease were studied morphometrically and ultrastructurally. In the dermis, most of the fungal elements appeared as sclerotic cells and their cell wall showed an irregular, worm-eaten leaf-like appearance; they seemed to be continuously attacked by polymorphonuclear neutrophils. The epidermis eliminated 10–20% of all the organisms in the skin lesions, and the hypha-forming activity tended to be higher in the epidermis than in the dermis. Ultrastructurally, basal keratinocytes facing the dermal abscess containing fungal elements frequently appeared as dark cells, suggesting an increased proliferation activity. Spinous keratinocytes facing intraepidermal microabscesses containing fungal elements showed an abnormal accumulation of tonofilaments and further early keratinization in the spinous cell layer. All of the morphological changes of the dermis and epidermis are regarded as defence reactions against the fungi existing in the skin lesions. There is a close relationship between tissue reactions and morphological changes of fungi in chromoblastomycosis.
    Type of Medium: Electronic Resource
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  • 3
    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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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 282 (1990), S. 434-441 
    ISSN: 1432-069X
    Keywords: Hair cycle ; Human hair follicle ; Connective tissue sheath ; Hyaline membrane ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural changes of the connective tissue sheath (CTS), including the hyaline membrane, of human hair follicles during the hair cycle, were studied in normal scalp skin specimens. In early anagen, the CTS was composed of a thin basal lamina and surrounding collagen tissue. The collagen tissue gradually thickened during the development of the hair and hair follicle. In mature anagen hair follicles, the collagen tissue was separated into three layers. The inner collagen layer, just outside the basal lamina, was thin and composed of collagen fibres running longitudinally parallel to the hair axis. The middle collagen layer was very thick with its collagen fibres running transversely against the hair axis and surrounding the inner hair tissue. Many fibroblasts were present among the collagen fibres in the middle layer, whereas the inner layer contained almost none. In the outer collagen layer, collagen fibres ran in various directions parallel to the outer surface of the outer root sheath cells. In late anagen, the basal lamina became very thick. In catagen, the basal lamine and the inner collagen layer became corrugated and showed oedematous change and degeneration. Surrounding fibroblasts showed active production of new collagen fibres, which seemed to fill the spaces left by the retraction of the hair follicle and hyaline membrane. These ultrastructural changes of the CTS show that there may be dynamic metabolic changes of the connective tissue around human hair follicles during the hair cycle.
    Type of Medium: Electronic Resource
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  • 5
    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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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 6 (1968), S. 247-264 
    ISSN: 1432-1106
    Keywords: Deiters neurones ; Disinhibition ; Cerebellum ; Cats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following the stimulation of cerebellar cortex, a slow depolarization developed in the neurones which were impaled with microelectrodes in the dorsal portion of the nucleus of Deiters. Characteristically, it was produced bilaterally from a wide area of the culmen and, with double shock stimulation at brief intervals, showed a marked potentiation, often in association with a later depression. After repetitive stimulation of the cerebellar cortex the slow depolarization was prolonged for a period of many seconds. Even stimulation of the spinal cord caused similar depolarization. By intracellular injection of currents and ions, the depolarization was shown to be disinhibition, i. e., removal of background inhibition. Accordingly, it was confirmed that there was a steady production of IPSPs in dorsal Deiters neurones, which diminished during the phase of disinhibition. As the possible source of these background IPSPs, the Purkinje cell axons within the nucleus of Deiters were found to be discharging rhythmically at a rate of 20–90/sec, and in fact they were depressed very effectively after cerebellar stimulation. At the same time, volleys along Purkinje cell axons produced by a testing cerebellar stimulation also were diminished, indicating a depression in the excitability of Purkinje cells.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1106
    Keywords: Deiters neurones ; Inhibition ; Climbing fibre responses ; Inferior olive
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intracellular recording with microelectrodes has been employed to reveal the causal relationship between the trans-synaptic activation of cerebellar Purkinje cells and the postsynaptic inhibition of Deiters neurones. Cerebellar stimulation produced in Deiters neurones not only monosynaptic IPSPs with latency of 0.9–1.5 msec, but also the delayed IPSPs at 1.5–9 msec. Correspondng to the latter, Purkinje cells were found to be activated orthodromically with the characteristic climbing fibre responses (CFRs), the latency varying from 0.8 up to 10 msec. On the other hand, stimulation of the inferior olive first induced EPSPs in Deiters neurones, presumably monosynaptically, then with a short delay of less than a millisecond CRFs in Purkinje cells of the anterior lobe, which in turn were succeeded by IPSPs in Deiters neurones after a further delay of a millisecond. Spinal stimulation activated the inferior olive trans-synaptically and thereby produced CFRs in Purkinje cells and a sequence of EPSPs and IPSPs in Deiters neurones. Close correlation between these spinal-induced events in both neurone species was further indicated by the concurrence of their fluctuations in intensity, these fluctuations being characteristic of the spino-olivary transmission mechanism. These results strongly support the postulate that the cerebellar Purkinje cells are inhibitory in their action upon Deiters neurones.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-1106
    Keywords: Axon reflex ; Deiters neurones ; Cerebellar afferents ; Cats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary When recording intracellularly from cat's Deiters neurones, stimulation of the anterior lobe of the cerebellar cortex produced excitatory postsynaptic potentials (EPSPs) monosynaptically, in addition to the inhibitory ones (IPSPs) that were identified previously as being produced via Purkinje cell axons. The EPSPs were induced bilaterally from a wide area of the anterior and posterior lobes of the cerebellum, in contrast to the IPSPs that were evoked only ipsilaterally, mainly from the vermal cortex. The latency of the EPSPs was slightly, but significantly, shorter than that of the IPSPs. The presynaptic impulses responsible for these EPSPs were represented by the discrete field potentials and also by unit spikes of individual fibres. The pathway for these EPSPs and presynaptic impulses was pursued by testing their interference, in the manner of impulse collision and refractoriness, with those induced from various spots within or outside the cerebellum. It is found that the excitatory fibres for Deiters neurones extend transversely, and probably longitudinally too, over the culmen and pass out of the cerebellum through cerebellar peduncles. The major portion of them appears to originate from the medulla and a minority from the spinal cord. It is postulated that cerebellar afferents from these structures have synapses with Deiters neurones via their collateral branches, through which a kind of axon reflex occurs to Deiters neurones during stimulation of the cerebellar cortex.
    Type of Medium: Electronic Resource
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  • 9
    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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  • 10
    ISSN: 1432-1106
    Keywords: Adaptation ; Vestibular ; Ocular ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adaptability of the horizontal vestibulo-ocular reflex (HVOR) and the optokinetic response (OKR) was examined in alert albino rabbits during sustained runs lasting 5–12 h under four different stimulus conditions. (1) Sinusoidal rotation of the rabbit in darkness by 5 ° at 1/10 Hz, or (2) sinusoidal movement of a vertical slit light by 2.5 ° or 5 ° at 1/10 Hz around the optical axis of the stationary rabbit, affected the gain of neither the HVOR nor the OKR. (3) Combination of the stimulus as in (1) with the stationary slit light increased the gain of the HVOR gradually. A plateau at about 140% of the initial control was reached in 5 h. (4) Combination of the stimulus as in (1) with the slit light movement by 10 ° in phase with the turntable decreased the HVOR gain gradually, a plateau being obtained at about 70 % of the initial control in 5 h. Changes of the HVOR gain induced in conditions (3) and (4) were not frequency-specific and accompanied by no significant modification of either the gain or phase of the OKR or the linear property of HVOR-OKR interaction. A small but significant change of the HVOR phase was also detected under the condition (3) but not (4).
    Type of Medium: Electronic Resource
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