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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Archives of gynecology and obstetrics 223 (1977), S. 195-204 
    ISSN: 1432-0711
    Keywords: Electron microscopy ; Human endometrium ; Nucleus ; Nucleolus ; Channel system ; Elektronenmikroskopie ; Menschliches Endometrium ; Nukleus ; Nukleolus ; Channel-System
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Nuclear-Channel-System ist eine runde bis ellipsoide Struktur, deren Tubuli querangeschnitten oder längsangeschnitten in eine elektronendichte Matrix eingebettet sind. Das NCS liegt meist der Kernmembran dicht an, die in diesem Bereich Einziehungen aufweist. Gelegentlich ist ein Kontakt der Kernmembran mit der Membran eines Tubulus zu beobachten. Im NCS sind Partikel festzustellen, die den 150 Å großen Partikeln des Nucleolus vergleichbar sind, was auf einen Gehalt des NCS an RNA schließen läßt. In hier vorliegenden Untersuchungen konnte das NCS in Zellkernen endometrialer Drüsenzellen während der mittleren und späten Proliferationsphase beobachtet werden. Diese Befunde sprechen gegen eine zwingende Abhängigkeit des Auftretens des NCS vom Zeitpunkt der Ovulation. Das NCS kann somit nicht als eine für postovulatorisches Endometrium typische Struktur angesehen werden. Offensichtlich bestehen zwischen den hormonellen Faktoren und der Ausbildung des NCS Beziehungen, deren Bedeutung bis heute nicht sicher beurteilt werden kann.
    Notes: Summary The Nuclear Channel System (NCS) is a distinct endometrial pattern as observed by transmission electron microscopy. The NCS was identified in the present study in cell nuclei of endometrial glands during mid and late proliferation. These observations do not support the concept that the NCS develops at the ovulation, and is therefore not a typical post ovulatory structure. It is suggested that there are relations between hormonal factors and the development of the NCS which are as yet no clarified.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0711
    Keywords: Electron microscopy ; Stereology ; Human liver ; Oral contraceptives ; Elektronenmikroskopie ; Stereologie ; Menschliche Leber ; Orale Kontrazeptiva
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurden Leberbiopsien von 12 Frauen feinstrukturell-morphometrisch untersucht, die über einen Zeitraum von 2 Monaten bis zu 8 Jahren ein Kombinationspräparat zur hormonellen Antikonzeption eingenommen hatten. Die stereologischen Daten wurden bereits vorher erstellten Basiswerten für normale Lebern (Roessner et al., 1977) gegenübergestellt und auf signifikante Unterschiede hin überprüft (p〈0,001). Eine deutliche Volumenzunahme lysosomaler Zelleinschlüsse pro ml Hepatocyten und eine leichte Cytoplasmavergrößerung bei gleichzeitiger Verkleine-rung der Nuclei kennzeichnen die Veränderungen der Hepatocyten. Alle übrigen ermittelten Parameter lassen den Schluß zu, daß wesentliche Alterationen der Ultrastruktur der menschlichen Leber nach hormoneller Kontrazeption nicht auftreten. Ob damit auch funktionelle Alterationen auszuschließen sind, kann hier nicht beantwortet werden.
    Notes: Summary Liver biopsies from 12 healthy women were investigated morphometrically — according to the methods of Weibel (1969). All women had taken an oral contraceptive agent during 2 til 76 months. The evaluated stereological datas were compared with base-line datas for normal human liver biopsies, which were elaborated in a previous investigation (Roessner et al., 1977). Statistical analysis was performed on an IBM 360/50 computer system, including F- and student's t-test. In the liver biopsy-specimen from the women, which were on oral contraceptives, the volume-density of lysosomes per ml hepatocytes shows a pronounced, significant (p〈0.001) increase. A moderate increase of cytoplasm is combined with decrease of nuclei-volume. The surface-densities of the rough and smooth endoplasmatic reticulum do not differ significantly from the datas calculated from normal human liver biopsies. All other datas too demonstrate that there are no striking changes in the ultrastructure of human liver, caused by oral contraceptives. Functional alterations however can not be excluded.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 259 (1977), S. 225-234 
    ISSN: 1432-069X
    Keywords: Granuloma annulare ; Necrobiosis of collagen ; Palisading granuloma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Neun Fälle von Granuloma annulare in verschiedenen Entwicklungsstadien wurden elektronenmikroskopisch untersucht, insbesondere Kollagenveränderungen, das entzündliche Infiltrat und Gefäßalterationen. Die nekrobiotischen Veränderungen des Kollagens bestehen in Auflockerung der Bündel vom Rande her, Schwellung der Fibrillen mit Verlust ihrer Querstreifung, völliger Desintegration des Kollagens und Niederschlägen von mucinösen Substanzen, Fibrin und Glykogen. In 2 Fällen waren sogenannte “filamentöse quergestreifte Aggregationen” (= sog. “long-spacing collagen”) nachweisbar. In späteren Stadien zeigte sich Kollagenneubildung. Im Infiltrat sind vor allem Histiocyten/Makrophagen mit Übergängen zu Epitheloidzellen und Riesenzellen, daneben auch Lymphocyten und später Neutrophile identifizierbar. Gefäßveränderungen bestehen in Endothelschwellung und Basalmembranverdoppelungen. Es besteht ein perivasculäres Infiltrat, jedoch keine echte Vaskulitis. Die Ergebnisse sprechen dafür, daß die Nekrobiose des Kollagens ohne primäre Vaskulitis ein initiales Ereignis bei Granuloma annulare darstellt. Pathogenetisch wird ein Immungeschehen vom verzögerten Typ diskutiert.
    Notes: Summary Nine cases of granuloma annulare at different stages of development were investigated electron microscopically. Special attention was given to collagen changes, to the cellular infiltrate, and to vascular changes. The necrobiotic changes of the collagen were: loosening of the fibers at the borders of the bundles; swelling and loss of cross-striation of the fibrils; and complete degradation of the collagen, with precipitation of mucinous and fibrin material and of glycogen. In 2 cases “cross-banded filamentous aggregations” were present. In later stages new collagen synthesis occurred. In the infiltrate, histiocytes/macrophages were seen developing into epithelioid and giant cells. In addition, numerous active lymphocytes and, at later stages, some neutrophils were found. Vascular changes consisted of endothelial swelling and duplications of the basal lamina. A perivascular infiltrate was present, but no distinct vasculitis was seen. Our results indicate that the necrobiosis of the collagen without primary vasculitis may be an initial event in granuloma annulare. A delayed hypersensitivity mechanism is discussed with regard to pathogenesis.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 27 (1977), S. 61-70 
    ISSN: 1432-1106
    Keywords: Amygdala ; Commissural fibers of the fimbria ; Electrophysiology ; Lesions ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Single shock stimulations have been applied stereotaxically and bilaterally in the region of the caudo-thalamic groove of the cat. These stimulations elicit diphasic potentials in the amygdala. Using combined methods of stimulation and lesion, it has been demonstrated that these electrical responses are due to the excitation of fibers projecting rostrally in the lateral border of the contralateral fimbria and caudally in the homologous part of the homolateral fimbria. A commissural path has been identified in the rostral part of the fimbria-fornix. Analysis of the experimental data has shown that the projection system consists of a discrete bundle of fibers which probably reaches the amygdala directly, in the dorsal part of the basal nucleus. The length of the explored portion of this pathway has been measured. The calculated conduction velocity of this amygdalopetal commissural component of the fimbria is 4.5 m/sec.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 27 (1977), S. 131-141 
    ISSN: 1432-1106
    Keywords: Colliculus superior ; Single neurons ; Eye movements ; Head movements ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 452 single neurons from the superior colliculus were recorded in awake and non-paralysed cats. 75 neurons were obtained from cats with unrestrained horizontal head movements. 228 neurons remained unaffected by saccadic eye movements. Eye movement related discharge followed the onset of saccades in 156 neurons either only in the presence of a visual pattern (92 neurons) or in darkness, too (64 neurons). The latter reaction type probably depends on eye muscle afferents. In 48 neurons eye movement related activity preceded the onset of eye movements. 12 neurons fired in synchrony with eye movements of any direction (type I). 30 neurons were excited during contralaterally directed eye versions within or into the contralateral head related hemifield. They were inhibited when the eyes moved within or into the ipsilateral head related hemifield (type II). 6 neurons with constant maintained activity during fixation were inhibited by ipsilaterally directed saccades, but remained unaffected by contralateral eye movements. Head movement related discharge followed the onset of head movements in 20 neurons only in presence of a visual pattern and also in darkness in 6 neurons. Ipsilateral head movements or postures strongly suppressed maintained activity and visual responsiveness of some neurons. 15 neurons discharged in synchrony with and prior to contralateral head movements. Ipsilateral head movements inhibited these neurons. Activation or inhibition were usually related to movement and to posture, exceptionally to movement or to posture. Electrical stimulation of recording sites of these neurons through the recording microelectrode elicits contralateral head movements.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-1106
    Keywords: Descending auditory pathways ; Superior olivary complex ; Cochlear nuclear complex ; Axoplasmic flow ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The descending pathways from the superior olivary complex (SO) to the cochlear nuclear complex (CN) were investigated in 58 cats using labelled aminoacid and horseradish peroxidase transport techniques. Descending connections were found coursing bilaterally through the trapezoid body (TB) and ipsilaterally in the intermediate and dorsal acoustic striae. The dorsolateral periolivary nucleus (DLPO) sends fibres through both the intermediate and dorsal striae, which are joined by others from the lateral preolivary nucleus (LPO). Both the latter nucleus and the medial preolivary nucleus (MPO) give rise to a bilateral descending projection which traverses TB. The distribution of these descending pathways within CN is described (although the technique did not permit precise synaptic identification). The possible implications of these pathways for response patterns at the level of CN are discussed.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 28 (1977), S. 153-166 
    ISSN: 1432-1106
    Keywords: Cat ; Spinal cord ; Dorsal horn ; Dendritic fields ; Golgi stain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Observations of neurons in dorsal horn laminae IV–VI of the lumbosacral segments of Golgi-stained spinal cords in kittens and adult cats revealed laminar differences in dendritic architecture. Many neurons in lamina IV had dense, bushy dendritic fields. Lamina V contained, in addition to bushy cells similar in appearance to those of lamina IV, increasing numbers of neurons with radiating dendritic fields. Lamina VI was composed almost exclusively of neurons with radiating dendritic fields. These qualitative differences among laminae were accompanied by systematic variations in mean dendritic spread, which increased more than two-fold in adult cats between laminae IV and VI. A second gradient of dendritic spread was found within individual laminae: dendritic spread, particularly medial to lateral spread, increased for successively more lateral cells within a lamina. These differences in the spread of dendrites for neurons in different regions of the dorsal horn may be related to variations in the areas of peripheral receptive fields of dorsal horn neurons.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 28 (1977), S. 325-333 
    ISSN: 1432-1106
    Keywords: Spatial contrast sensitivity ; Cat ; Grating pattern ; Flicker ; X- and Y-cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using behavioral techniques, contrast sensitivity for flickering and stationary gratings was measured in ordinary cats. Gratings of low spatial frequency were more easily detected by the cat when temporal modulation was present, but at high spatial frequencies temporal modulation reduced grating visibility. These psychophysical results are consistent with neurophysiological evidence for the existence of two classes of visual cells in the cat, which are distinguishable in terms of their spatio-temporal response properties.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 29 (1977), S. 107-122 
    ISSN: 1432-1106
    Keywords: Area 17 ; Lateral suprasylvian area ; Remote visual stimuli ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Single units were recorded extracellularly from area 17 and lateral suprasylvian area (LSSA) in curarized cats. Visual stimuli, usually a 10 ° black spot, were introduced abruptly in the visual field remote from the discharge area of a neuron's receptive field and moved at a speed of about 30 °/sec. The effect of these remote stimuli (S2) on the response to a restricted visual stimulus (S1) crossing the discharge area was studied. It was found that most units in area 17 were not affected by the presentation of remote stimuli, the remainder being either slightly facilitated or slightly inhibited. In contrast the LSSA neurons were usually inhibited by the presentation of S2: this effect was strong, was present in all classes of LSSA neurons and was independent of the relative directions of movement of S1 and S2. On the basis of these data and those previously obtained from the superior colliculus it is concluded that the way the extrageniculate centres respond to a stimulus abruptly introduced in the visual field is substantially different from that of the striate cortex. Only in the extrageniculate centres a new stimulus, besides exciting the neurons which correspond to the position of the stimulus in the field, concomitantly decreases the responses of neurons located in positions of the visual field remote from that stimulus. Possible behavioral implications of the findings are discussed.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 30 (1977), S. 89-105 
    ISSN: 1432-1106
    Keywords: Extrageniculate visual system ; Pretectum ; Efferent connections ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Direct projections from the pretectum in the cat were investigated by means of the Nauta-Gygax and the Fink-Heimer method in an attempt to identify the morphological substrates subserving possible neural mechanisms involved in visual behaviour and reflexes. Degeneration in the diencephalon was found ipsilaterally in the nucleus limitans, lateral pulvinar nucleus, lateral posterior nucleus, lateral dorsal nucleus, dorsal and ventral lateral geniculate nuclei, centre medianparafascicular complex, central medial nucleus, paracentral nucleus, central lateral nucleus, ventroanterior and ventrolateral nuclear complex, zona incerta, H field of Forel and the reticular nucleus. The pretectal fibers projecting to the ventral lateral geniculate nucleus appeared to be topically organized. In the midbrain, the pretectal fibers were observed to terminate ipsilaterally within the superior colliculus, nucleus of Darkschewitsch, dorsolateral portion of the red nucleus, lateral terminal nucleus of the accessory optic tract and the reticular formation, and bilaterally within the central gray, interstitial nucleus of Cajal and the rostral portion of the nucleus of Edinger-Westphal. Degeneration in the superior colliculus was marked in laminae II, III and IV. The fibers arising from more anterior part of the pretectum appeared to be distributed more medially in laminae II and III. The pretectopontine fibers terminated ipsilaterally in the paramedial and the dorsolateral pontine nuclei as well as the reticular formation. In the inferior olivary complex, degeneration was found in caudal levels of the dorsal cap and β-nucleus, and additionally in the rostral portion of the dorsal accessory olive.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 30 (1977), S. 155-160 
    ISSN: 1432-1106
    Keywords: Cat ; Postural reflexes ; Visual and vestibular reflex modulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The excitability of hindlimb extensor and flexor motoneurons is tonically modulated by animal tilt and a large visual stimulus rotating about the animal's line of sight. This direction-specific modulation is opposite for extensor and flexor motoneurons and opposite for optokinetic and vestibular stimuli, thus combining to a functionally significant pattern of postural reflexes.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 30 (1977), S. 275-296 
    ISSN: 1432-1106
    Keywords: Striate cortex ; Simple and complex cells ; Visual texture ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The responsiveness of 254 simple and complex striate cortical cells to various forms of static and dynamic textured visual stimuli was studied in cats, lightly anaesthetised with N2O/O2 mixtures supplemented with pentobarbitone. Simple cells were unresponsive to all forms of visual noise presented alone, although about 70% showed a change in responsiveness to conventional bar stimuli when these were presented on moving, rather than stationary, static-noise backgrounds. Bar responses were depressed by background texture motion in a majority of cells (54%), but were actually enhanced in a few instances (16%). In contrast, all complex cells were to some extent responsive to bars of static visual noise moving over stationary backgrounds of similar texture, or to motion of a whole field of static noise. The optimal velocity for noise was generally lower than for bar stimuli. Since moving noise backgrounds were excitatory for complex cells, they tended to reduce specific responses to bar stimulation; in addition, directional bias could be modified by direction and velocity of background motion. Complex cells fell into two overlapping groups as regards their relative sensitivity to light or dark bars and visual noise. Extreme examples were insensitive to conventional bar or edge stimuli while responding briskly to moving noise. In many complex cells, the preferred directions for motion of noise and of an optimally oriented black/white bar were dissimilar. The ocular dominance and the degree of binocular facilitation of some complex cells differed for bar stimuli and visual texture. Preliminary evidence suggests that the deep-layer complex cells (those tolerant of misalignment of line elements; Hammond and MacKay, 1976) were most sensitive to visual noise. Superficial-layer complex cells (those preferring alignment) were less responsive to noise. Only ‘complex-type’ hypercomplex cells showed any response to visual noise. We conclude that, since simple cells are unresponsive to noise, they cannot provide the sole input to complex cells. The differences in the response of some complex cells to rectilinear and textured stimuli throw a new light on their rôle in cortical information-processing. In particular, it tells against the hypothesis that they act as a second stage in the abstraction of edge-orientation.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 30 (1977), S. 353-368 
    ISSN: 1432-1106
    Keywords: Visual deprivation ; Cat ; Behavior ; Perimetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Visual fields of 15 monocularly deprived (MD) cats and 2 monocularly tested normal adult cats, were measured using stationary stimuli at fixed distances in the horizontal plane. Compared to the visual fields of monocularly tested normal cats, those of the deprived eyes of MD cats were found to be restricted to the ipsilateral hemifield up to the midline. This finding appeared to be permanent since it was measured both in cats tested early (4 cases) and late (11 cases) after deprivation. In addition, it seemed to be independent whether the nondeprived eye was closed by reverse suturing (13 cases), or was left open after deprivation and closed only temporarily during testing (2 cases). Visual fields were also found to be restricted to the ipsilateral hemifield, if MD cats were tested at several levels above the horizontal plane or in a hemisphere (23 cm radius) in which the superior and inferior segment of the visual space could be tested (6 cases). The results are controversial to those of Sherman (1973) who described the visual fields of MD cats to be restricted to the monocular (60–90 ° ipsilateral) segment. The differences observed in our results compared to those of Sherman could not be explained by experimental factors, since testing MD cats by the method employed by Sherman (8 cases) also resulted in visual fields covering the monocular as well as the binocular part of the ipsilateral side. Consequently, Sherman's hypothesis (1974b), that for MD cats the geniculocortical pathways dominate in the visual behavior and that retinotectal pathways are somehow suppressed, could not be confirmed by our results. In our experiments the visual behavior demonstrated by MD cats seemed to be developed mainly through retinotectal pathways. In MD cats in which after the deprivation period the non-deprived eye remained open, the monocular part seemed to be of more importance than the binocular segment; permanent closure of the normal eye seemed to lead to a further shift towards the binocular segment. Therefore, in non-reverse sutured MD cats some suppression of retinotectal pathways by imbalanced corticotectal pathways may be present, but not as elaborate as described by Sherman. This slight suppression is overcome by reverse suturing. The mechanism of release from suppression of retinotectal pathways is unknown, its possible localisation is discussed.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 28 (1977), S. 259-278 
    ISSN: 1432-1106
    Keywords: Cat ; Lateral geniculate nucleus ; X- and Y-cells ; Visual deprivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Retrograde axonal transport of horseradish peroxidase (HRP) was used to identify two populations of cells in the lateral geniculate nucleus (LGN) of the cat. HRP was injected into area 17 and 18 separately in the same animal, and the neuronal somata giving rise to thalamo-cortical axons, identified by the presence of granular HRP reaction product within them, were measured. The mean size of LGN neurones labelled by injections in area 17 (“17-relay” cells) was less than of neurones filled from area 18 (“18-relay” cells). Similar separate injections into area 17 and 18 of monocularly deprived kittens also showed that in non-deprived LGN laminae 17-relay cells were, on average, smaller than 18-relay cells. In deprived laminae, 17-relay cells were some 20% smaller than in nondeprived laminae, but deprived 18-relay cells were 50–60% smaller than normal, being on average, actually smaller than deprived 17-relay cells. We conclude that the population of large LGN neurones projecting to area 18 is more severely affected by monocular deprivation than the smaller neurones projecting to area 17, and discuss the relationship of the morphological results to physiologically defined X and Y cells in the LGN.
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  • 15
    ISSN: 1432-1106
    Keywords: Pons ; Cerebellum ; Pontocerebellar projection ; HRP method ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary By use of the retrograde axonal transport of horseradish peroxidase (HRP) the projection to the anterior lobe from the pontine nuclei was mapped in detail. In 18 cats 0.1–0.5 gml of a,50% suspension of Sigma VI or Serva HRP was injected in the anterior lobe under visual guidance or stereotactically. The main findings are as follows: 1. The projection to the vermis of the anterior lobe is bilateral with a contralateral preponderance (about 3/4). 2. The vermis of the anterior lobe receives afferents from a restricted, laterally located region in the caudal part of the pons. Dorsal parts of this region project anteriorly (lobules I–III), ventral parts posteriorly (lobulus V). 3. The projection to the intermediate-lateral part is almost exclusively contralateral and is considerably heavier than the projection to the vermis. 4. The intermediate-lateral part receives afferents from two pontine regions. One is located laterally and coincides caudally with the region projecting to the vermis. The other is located medially and projects only sparsely to the vermis. 5. Within the projection from the lateral pontine region to the intermediate part there is a somatotopical pattern corresponding to that within the projection to the vermis. Within the medial pontine region the somatotopical pattern is less clear, but there is a tendency for cells projecting to lobules III–IV to be located more ventrolaterally than those sending their fibres to lobulus V. 6. The pontine regions projecting to the anterior lobe seem to coincide closely with those receiving fibres from the primary sensorimotor cortex, particularly the lateral part of the anterior sigmoid gyrus and medial part of the posterior sigmoid gyrus, as determined previously (P. Brodal, 1968a).
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 27 (1977), S. 35-50 
    ISSN: 1432-1106
    Keywords: Lateral geniculate nucleus ; Cat ; Dark adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The receptive fields of LGN cells were investigated with stationary light and dark spot and annulus stimuli. Stimulus size and background intensity were varied while stimulus/background contrast was kept constant. The speed of dark adaptation varied considerably from cell to cell. Dark adaptation made responses more sustained in all neurones and eliminated the oscillatory on-responses evoked under some conditions in the light-adapted cells. Dark adaptation led also to a disappearance of early phasic inhibition in on-responses, and increased response rise time and latency. The power of surround responses to inhibit centre responses decreased slightly at low levels of light adaptation in LGN cells but much less than in retinal ganglion cells. Some other traces of changing retinal surround effects also appeared in the LGN on dark adaptation. For example, the functional size of receptive fields increased at low levels of illuminance as has been observed in retinal ganglion cells and the receptive fields as estimated from response peaks were larger than those estimated from sustained components.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 373 (1977), S. 191-211 
    ISSN: 1432-2307
    Keywords: Myeloproliferative disorder ; Thrombocytes ; Megakaryocytic-granulocytic myelosis ; Bone marrow biopsy ; Megakaryocyte lineage ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of the bone marrow in chronic megakaryocytic-granulocytic myelosis (CMGM) was studied in 5 nontreated patients to investigate possible malignant proliferation of megakaryocytes and the role of megakaryopoiesis in fibrillogenesis, terminating in osteomyelofibrosis. In comparison with normal megakaryopoiesis there is an enormous increase of the megakaryocytic cell line and many immature and atypical forms are seen. Most conspicuous are microforms, nuclear-cytoplasmic disorganization and nuclear inclusions. Asynchrony of maturation causes abnormal thrombocytogenesis with premature detachment of platelets resulting in immature and peculiar giant forms of thrombocytes. Besides megakaryocytes appearing superficially normal the maturation anarchy of many cells is so severe that by analogy with observations in other leukaemic cells these abnormalities are thought to be representative of a malignant growth. Moreover, there is a striking accumulation of microfibrils and single collagen fibres around megakaryoblasts. Since these cells contain all those organelles commonly associated with fibre production the initial step for fibrillogenesis may therefore arise from the megakaryoblasts prior to platelet release, or any fibroblast proliferation.
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  • 18
    ISSN: 1432-2307
    Keywords: Ulcerative colitis ; Immunoperoxidase ; Complement demonstration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Inflammatory cell infiltrates in ulcerative colitis have been investigated by means of the immunoperoxidase method and by electronmicroscopy. Considerable morphological and functional changes of the local plasma cell population have been found. The absolute number of plasma cells is raised with a marked increase of IgG-cells and a relative decrease of IgA-cells. In particular complement (C3) has been demonstrated at the basement membrane of the surface epithelium and between epithelial cells. The significance of these findings, as a local humoral immune response, is briefly considered, with regard to their possible pathogenetic importance in aggravating and perpetuating the disease.
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 375 (1977), S. 1-12 
    ISSN: 1432-2307
    Keywords: Adenoid cystic carcinoma ; Cylindroma ; Salivary glands ; Mucosubstances ; Cytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The distribution of mucosubstances in adenoid cystic carcinoma was investigated, and an attempt was made to characterize histochemically the various mucosubstances present. For these purposes the high iron diamine technique (HID), as well as the Astra blue, aldehyde fuchsin and Alcian blue staining methods were employed. Alcian blue was further combined with the periodic acid-Schiff (PAS) technique, the Alcian blue being applied at pH levels between 0.5 and 2.5. In addition the effects of neuraminidase and hyaluronidase treatment as well as methylation and acid hydrolysis procedures on the staining qualities were studied. Acidic mucosubstances with varying histochemical properties were present in different structures of the neoplasm. The characteristic pseudocyst, a major structural component of the neoplasm, stained strongly with HID, Astra blue, aldehyde fuchsin and Alcian blue at low pH. These staining reactions were markedly suppressed by hyaluronidase treatment, and are apparently attributable to the presence of chondroitin 4- and/or 6-sulfate. Employing the Alcian blue-critical electrolyte concentration technique, the basophilia of the pseudocysts was suppressed at a concentration of 0.5–0.6 M MgCl2, which might indicate polysaccharides of relatively low degree of sulfation. An additional, non-sulfated acid mucin could also be demonstrated in these structures. In certain duct and gland like structures of the tumours, a change in staining pattern from blue or blue-red to red could be observed after exposure of the sections to neuraminidase and subsequent staining with the Alcian blue (pH 2.5)-PAS sequence. Similar observations were also made when the pH of the Alcian blue was lowered to 1.5–1.0, as well as after acid hydrolysis. These findings afford evidence for the presence of a neuraminidase susceptive sialomucin in certain epithelial secretions of the tumor. At the ultrastructural level the replicated basement lamina of the pseudocysts displayed a strong positive reaction with the PA-CrA-silver staining technique. Furthermore, amorphous material within the lumina of small duct like structures also displayed a positive reaction. The amorphous material of the cystic compartments was less reactive.
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  • 20
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    Virchows Archiv 375 (1977), S. 123-128 
    ISSN: 1432-2307
    Keywords: Esthesioneuroblastoma ; Light microscopy ; Electron microscopy ; Argyrophil reaction ; Formaldehyde-induced fluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of esthesioneuroblastoma was examined by histological, histochemical and electron microscopic techniques. The tumour cells showed an argyrophil reaction with the Grimelius technique and contained cytoplasmic secretory granules, but in contrast to previous reports were devoid of histochemically demonstrable biogenic amines. For routine diagnosis the argyrophil technique may be useful in differentiating this type of tumour from epidermoid carcinoma.
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  • 21
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    Virchows Archiv 375 (1977), S. 13-22 
    ISSN: 1432-2307
    Keywords: Target-targetoid phenomenon ; Histochemistry ; Electron microscopy ; Z-band alteration ; Incomplete innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Target and targetoid fibers in a muscle biopsy from a patient with paralysis of the deltoid and supraspinatus muscles were studied by light and electron microscopy. The probable cause of the neuropathy was tumor compression. Target and targetoid change was exclusively confined to hypertrophic or normal-sized fibers. Morphometric evaluation of the target and targetoid fibers showed no significant difference between them. With the electron microscope, up to 4 structural zones were seen in the typical target fiber but many were devoid of either zone 2 (halo) or zone 3, or both. It was conceivable that focal irregularity and streaming of Z-bands were the primary alterations in the process of target-targetoid fiber formation, and that this phenomenon was induced both by partial residual innervation as well as re-innervation.
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  • 22
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    Virchows Archiv 375 (1977), S. 147-157 
    ISSN: 1432-2307
    Keywords: Electron microscopy ; Atherosclerosis ; Pigeon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The atherosclerotic lesions, associated with the celiac intimal smooth muscle cushions, of four and five year old White Carneau pigeons were studied with the light and electron miscroscopes. Light microscopic examination of the spontaneous lesions demonstrated large intimal cushions composed of smooth muscle, abundant collagen, clusters of foam cells and cholesterol crystal clefts. Ultrastructural examination of the intimal atheroma revealed dilatations between apposing endothelial cells which contained a flocculent material, similar to that seen in the subendothelial space. The subendothelial compartment contained abundant collagen, extracellular lipid, vesiculated material and cell processes which contained a flocculent matrix and tubular-like elements. In addition, fibroblast-like interlaminar cells were often observed. Numerous intimal smooth muscle cells were seen which displayed varied morphology. Abundant foam cells were also present within the intimal atheromas. The presence of atherosclerotic lesions in preexisting intimal smooth muscle cushions suggests that hemodynamic factors may be important in the progression of these spontaneous lesions. Endothelial cell dilatations may provide an important route of transport for circulating elements which may accumulate within the subendothelial space. Morphologically, it appears that the smooth muscle cells undergo modification and may represent the precursors of foam cells in this species.
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  • 23
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    Virchows Archiv 377 (1977), S. 43-48 
    ISSN: 1432-2307
    Keywords: Childhood cystinosis ; Liver ; Electron microscopy ; Dark cells ; Tight junctions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural findings in the liver in a case of childhood cystinosis are reported. Crystalline structures were found mainly in Kupffer cells. The presence of dark cells, with or without crystals, was the most striking feature observed. Such cells have already been noted within the kidney on one occasion when it was shown that the dark substance was L-cystine (Spear et al., 1971). In this case identical dark material was also found extracellularly. The data shows that free cystine can fill cell cytoplasm and extracellular spaces and the possibility that cystine overproduction may take place in the hyaloplasm should be considered. Extracellular location of cystine in the tubules might account for an increase in epithelial permeability and thus for the Fanconi syndrome.
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  • 24
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    Mycopathologia 60 (1977), S. 175-177 
    ISSN: 1573-0832
    Keywords: Aspergillus fumigatus ; Spore formation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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  • 25
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    Mycopathologia 61 (1977), S. 117-119 
    ISSN: 1573-0832
    Keywords: Prototheca ; Colorless alga ; Plastids ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract An ultrastructural investigation of six different species of Prototheca showed that all of them contained starch grains enclosed in double-membrane-bounded structures recognized as plastids. It is concluded that these unicellular species of Prototheca must be considered as non-photosynthetic algae.
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  • 26
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    Anatomy and embryology 152 (1977), S. 43-64 
    ISSN: 1432-0568
    Keywords: Habenula ; Ependyma ; Supraependymal cells ; Supraependymal axons ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The surface features of the ependymal lining of the habenular complex in rats, aged between three weeks and nine months, were studied by means of scanning and transmission electron microscopy. The ependyma of the medial habenular nucleus is heavily ciliated, the cilia obscuring underlying substructure in SEM — preparations. On the habenular commissure most cilia are arranged in tufts. Cilia are provided with segmental indentations and occasional apical thickenings. Vesicular protrusions of the ependymal cytoplasm into the ventricular lumen and the frequent occurrence of homogeneous supraependymal globules were interpreted as signs of ependymosecretory activity of nucl. hab. med. Supraependymal cells are most numerous on the anterior and superior surface of the habenular commissure. Cells presenting features identical to Kolmer (epiplexus) cells were identified on the ventricular surface of nucl. hab. med. in one specimen showing degenerative changes of undetermined aetiology in the habenular nuclei. It is therefore suggested that such cells need not necessarily be restricted to the choroid plexus. Supraependymal unmyelinated axons are particularly numerous on both nucl. hab. med. and commiss. hab. They make desmosome contacts (maculae adherentes) with the ependymal plasmalemma. Contacts presenting all features of typical synapses were not encountered. The vesicle population of the axonal profiles mainly comprises 35–50 nm translucent round vesicles besides small numbers of 60–100 nm dense-cored vesicles and large pleiomorphic vesicles. Most probably the axons belong to the well-established dense population of serotonergic axons in the dorsal part of the third ventricle.
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  • 27
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    Anatomy and embryology 150 (1977), S. 335-364 
    ISSN: 1432-0568
    Keywords: Caudate nucleus ; Hypothyroidism ; Development ; Electron microscopy ; synaptogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thyroid hormone exerts a powerful influence on CNS growth and maturation. Hypothyroidism early in life has long been known to cause disturbances in innate behavior, motor performance, severe and frequently irreversible mental retardation. In this deficiency, depressed caudate neurogenesis, cell migration and neuropil development during the rapid period of CNS growth may contribute to the clinical picture of perceptual handicaps often seen in cretins. Light microscopic and Golgi studies of the developing caudate nucleus in thyroid deficiency have been carried out to help attain insights into the mechanisms whereby the extrapyramidal system regulates motor function. The ultrastructural study of caudate nuclear cytogenesis and synaptogenesis in normal and hypothyroid states provides more detailed information for further analysis of the problem. Hypothyroidism was induced from birth by adding propylthiouracil to the food and drinking water of lactating dams. Linear development of the caudate nucleus of both normal and hypothyroid rats at ages 8, 14, 20, 30 and 42 days was studied by electron microscopy. Thyroid glands were examined by light microscopy to assess the normal and deficient states. Immature cells, primitive processes and synapses were the characteristic features of the 8-day-old normal caudate nucleus. Distinctively wide cisternae of the rough endoplasmic reticulum, loosely packed Golgi apparatus and chromatin clumps throughout the nuclei of the neurons were significant early morphologic variations. The dramatic cytoarchitectural maturation in the 14- and 20-day normal caudate neuropil points to the rapidity of developmental rate. After the growth spurt of the first three weeks a maturational plateau occurs which is characterized by well-formed neuronal cytoplasmic organelles, myelinated and non-myelinated axons, axon terminals, dendrites and their spines, and synapses. Thyroid deficiency causes a marked maturational delay of approximately 7 days in caudate neuronal proliferation, the elaboration of neuronal networks and the attainment of mature synaptic contents and membranes. This delay is evidenced by comparison of the structural similarities between 8-day-old normal and 14-day-old deficient rats; and additional comparisons between the 14-day-old normal and 20-day-old hypothyroid rats. A rapid “catch up” process in fine structural morphogenesis takes place in the period between days 14 and 30 in the deficient animals. Repression of thyroid function does not entirely prevent development of the caudate nucleus but allows a fairly extensive, though critically incomplete degree of maturation. This imperfection is manifested by a decrease in the number of synaptic contacts that persists even after the rapid “catch up” phenomenon of caudate synaptogenesis.
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  • 28
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    Anatomy and embryology 151 (1977), S. 109-118 
    ISSN: 1432-0568
    Keywords: Iris ; Mesenchymal cells ; Chicken embryo ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The iris anlage of 3–10 day old chicken embryos was studied by both light and electron microscopy. Serial semithin sections showed that some of the mesenchymal cells overlying the eye cup moved into the primitive eye cavity by the 3rd day of incubation. On the 4th day some of these cells came into close contact with the basement membrane of the dorsal iris epithelium. The bases of the epithelial cells were flat at this stage. Towards the 10th day they formed cytoplasmic processes which did not penetrate the basement membrane. Fine mesenchymal cytoplasmic processes and a large number of extracellular fibrils developed in the epithelial-mesenchymal interface. The fine mesenchymal processes came into close contact with the basement membrane of the posterior iris epithelium but did not penetrate it. Collagen-like material was observed within the cisternae of the rough ER of the mesenchymal cells at certain stages of development. Both, the mesenchymal cells and the collagen fibrils adjacent to the posterior iris layer disappeared by the 10th day when the entire iris epithelium was completely pigmented. The possible origin of the collagen fibrils and the differentiation of the posterior iris epithelium are discussed.
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  • 29
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    Anatomy and embryology 151 (1977), S. 127-139 
    ISSN: 1432-0568
    Keywords: Cilia ; Human heart ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Primary 9+0 cilia have been found in the embryonic and the adult human heart. Proximally the cilia show the typical (+0 filament arrangement. Rearrangement of the filaments occur in their distal regions. The cilia are usually found in deep invaginations of the cell membrane, but can also be found in a superficial position. Close connections are frequently found between cilia and thin cytoplasmic extensions from neighbouring cells.
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  • 30
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    Anatomy and embryology 151 (1977), S. 97-108 
    ISSN: 1432-0568
    Keywords: Chick embryo ; Placode ; Electron microscopy ; Invagination ; Midbody
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The otic, the lens and the nasal placodes have been examined in chick embryos between stages 10 and 18 of Hamburger and Hamilton. At the stage when each placode first becomes visible conspicuous differences have been seen in the surface morphology between those cells which will invaginate and form the placode and those which will remain on the surface of the head, forming the epidermis. The differences become more pronounced with increasing development. The placode cells possess many surface projections whilst the epidermal cells do not. These differences in surface morphology are related to other differences which are visible in TEM sections, the placode cells being highly columnar and extending the full depth of the placode, whilst the epidermal cells are cuboidal or even squamous. This modification in cell shape of the placode cells is correlated with the presence of longitudinally orientated microtubules. The mechanism of invagination is discussed and evidence is presented which supports the idea that there is a migration of cells into the placode from one side. Such a phenomenon would help to explain the asymmetrical structure of the placode, including the presence of the overhanging lip.
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  • 31
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    Archives of dermatological research 260 (1977), S. 167-178 
    ISSN: 1432-069X
    Keywords: Electron microscopy ; Psoriasis pustulosa ; Spongiform pustule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Fünf Fälle von Psoriasis pustulosa wurden elektronenmikroskopisch untersucht. Die Hauptveränderungen im Corium bestanden in Capillardilatation mit intravasculären polymorphonukleären Leukocyten und Erythrocyten. Leukocyten traten durch die vasculären Spalten und Fenestrationen und wanderten durch das deutlich ödematöse Corium zur Epidermis. Lymphgefäße fanden sich ebenfalls. Histiocyten mit Langerhansgranula wurden in der Dermis und Epidermis beobachtet. Die morphologischen Veränderungen in der Epidermis waren abhängig von der Lokalisation und besonders stark ausgeprägt in der Nähe von voll entwickelten Pusteln in höheren Zellschichten. Früher beschriebene Befunde konnten bestätigt werden. Perinukleäre Cytolyse und andere Veränderungen in den Keratinocyten scheinen sekundär aufgrund des Ödems und der Ansammlung von Neutrophilen innerhalb der Epidermis zu entstehen. Immunologische Phänomene könnten hierfür verantwortlich sein.
    Notes: Summary Five cases of psoriasis pustulosa were examined by electron microscopy. The main features within the dermis were dilated capillaries filled with polymorphonuclear leukocytes and red cells. Neutrophils passed out of the vessels through the gaps and fenestrations and migrated towards the epidermis throughout the distinctly edematous corium. Lymphatic vessels could be found. Histiocytes containing Langerhans granules were observed in the dermis and epidermis. The morphological changes of the epidermis depented on the place examined and were most evident near fully developed pustules in the upper layers. The presence of previously described morphological findings could be confirmed. Perinuclear cytolysis and other changes in the keratinocytes, however, seem to be secondary, resulting from edema and accumulation of neutrophils within the epidermis. Immunological phenomenona may be responsible for the latter event.
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  • 32
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    Archives of dermatological research 260 (1977), S. 29-38 
    ISSN: 1432-069X
    Keywords: Cat ; Epidermis ; Histochemistry ; Enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Mit Hilfe von enzymhistochemischen Methoden wurden die Verteilung und die Aktivitäten verschiedener oxydativer und hydrolytischer Enzyme in der Epidermis der Hauskatze untersucht. Deutliche Aktivitäten oxydativer Enzyme konnten mit Ausnahme des Stratum corneum in allen epidermalen Zellagen beobachtet werden. Unter den nachgewiesenen hydrolytischen Enzymen zeigte besonders die unspezifische Esterase stark positive Reaktionen im Stratum granulosum und in den basalen Anteilen des Stratum corneum. Cholinesterase-Aktivitäten waren in der Epidermis der Katze nicht festzustellen. Die vorliegenden Ergebnisse von der Epidermis der dicht behaarten Hauskatze werden im Zusammenhang mit den Ergebnissen entsprechender Untersuchungen an der Epidermis spärlich behaarter Säugetierarten (z.B. Hausschwein und Mensch) diskutiert. Insgesamt weist das Enzymmuster der Katzenepidermis nur bedingt Parallelen zu demjenigen der Epidermis des Menschen auf, wobei speziell in der Verteilung und den Aktivitäten von Esterasen Abweichungen auftreten.
    Notes: Summary With the help of enzyme histochemical methods, the distribution and activities of several oxidative and hydrolytic enzymes in the epidermis of the densely-haired domestic cat have been studied. Distinct oxidative enzyme activity could be demonstrated in all epidermallayers except the stratum corneum. Among the hydrolytic enzymes investigated, strong reactions for non-specific esterases were visible especially in the str. granulosum and the basal lamellae of the str. corneum. Positive reactions for cholinesterases could not be observed in the cat epidermis. The results are discussed in relation to corresponding investigations on the epidermis of sparsely-haired mammals, e. g. the domestic pig and man. Generally the enzyme pattern of the cat epidermis only shows limited parallels to man, especially where esterase distribution is concerned.
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  • 33
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    Acta neuropathologica 37 (1977), S. 119-125 
    ISSN: 1432-0533
    Keywords: Amyloid polyneuropathy ; Electron microscopy ; Nerve fibers abnormalities ; Giant axons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two sporadic cases of amyloid polyneuropathy with clinical features corresponding to the Portuguese type of this disease were studied. Histological examination of sural nerve demonstrated a marked loss of myelinated and unmyelinated fibers in the case 1 due to axonal degeneration, high content of fibers with segmental demyelination and the occurrence of several enlarged axons filled with the 10 nm filaments (so-called giant axons). In the case 2 there was total loss of unmyelinated axons and myelinated fibers were nearly completely lacking. In the development of changes in the myelinated fibers their direct compression by amyloid deposits seems to play an important role. It leads to the appearance of both axonal degeneration and segmental demyelination. The latter seems to be due to local compression and it may involve many fibers. In the light of observations reported by other authors the mechanism of changes developing in unmyelinated fibers is explained by the presence of changes in the cells of posterior root ganglia, however the question whether some abnormalities seen in unmyelinated axons could not be related to the pressure exerted by amyloid deposits directly to these fibers, remains open.
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  • 34
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    Acta neuropathologica 37 (1977), S. 263-265 
    ISSN: 1432-0533
    Keywords: Progressive multifocal leukoencephalopathy ; Multiple sclerosis ; Demyelination ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Inclusions identical to those described in multiple sclerosis (MS) brain by Prineas (1975) have been seen by ultrastructural study of cerebral tissue in two elsewhere reported cases of Progressive Multifocal Leukoencephalopathy (PML). The meaning of these formations, which have been suggested to be related to a special process of demyelination in MS, is discussed in the light of the hypotheses concerning the demyelination mechanism in PML. Whatever might be their significance, these cytoplasmic non viral inclusions are not specific for MS.
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  • 35
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    Acta neuropathologica 39 (1977), S. 135-138 
    ISSN: 1432-0533
    Keywords: Clofibrate ; Striated muscle ; Histochemistry ; Electron microscopy ; Experimental animal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats were given daily injections of 0.2 or 0.5 g/kg chlorophenoxyisobutyrate (clofibrate) for 9 to 46 days. Lower leg muscles were studied with light and electron microscopy. Daily treatment with 0.5 g/kg of the drug for 26–46 days caused myopathic changes.
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  • 36
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    Acta neuropathologica 37 (1977), S. 69-72 
    ISSN: 1432-0533
    Keywords: Neuropathy ; Fibroblast ; Endoneurial edema ; Peripheral nerve ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary “Focal mucoid degeneration” was found in a N. suralis biopsy of a 8 year old child, diagnosed clinically and electrophysiologically as progressive muscular atrophy Charcot-Marie-Tooth.
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  • 37
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    Acta neuropathologica 37 (1977), S. 127-135 
    ISSN: 1432-0533
    Keywords: Slow infection ; Viral encephalomyelitis ; Electron microscopy ; C-Type virus ; Immunopathology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of visna, a slowly progressive meningo-encephalomyelitis of sheep, was studied in animals sacrificed one month after intracerebral inoculation of visna virus. The major pathological changes, representative of those seen during the first year after infection, consist of inflammation and minor focal destructive lesions of grey and white matter. The inflammatory infiltrates, both subependymal and perivascular as well as of the choroid plexus, were composed mainly of lymphocytes and macrophages with varying numbers of plasma cells. The demyelination seen was of the secondary or Wallerian type. There was no evidence of primary demyelination. Visna virions were not seen in any of the CNS material studied. The ultrastructural findings are compatible with the view that lesions in visna may be induced by a cell-mediated immune response. However, changes characteristic of an autoimmune reaction to myelin antigens were not observed.
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  • 38
    ISSN: 1432-0533
    Keywords: Perexiline maleate ; Drug-induced neuropathy ; Nerve biopsy ; Muscle biopsy ; Skin biopsy ; Electron microscopy ; Lysosomes ; Segmental demyelination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pathological findings in four nerves and muscles and in one skin biopsies from four patients treated with perhexiline maleate for angina pectoris are reported. In every case, a muscular denervation atrophy and a decrease in the large diameter myelinated fibers were observed. Only one case showed a decrease of the total number of myelinated fibers, on quantitative studies. The electron microscopic study of each nerve displayed findings consistent with a predominant schwannian degeneration, associated with a few onion bulbs formations and, in two cases, with a mild wallerian degeneration. The most striking finding consisted in the presence of polymorphous membrane-bound inclusions reminding the morphology of lysosomal complex lipids. These structures were very abundant in Schwann cells, but they were seen also in fibrocytes, endothelial and pericytic cells. Similar inclusions were present in the single muscle and skin biopsies studied by electron microscopy. In the muscle, they were seen in muscular cells as well as in endothelial and pericytic cells. In the skin, similar inclusions were observed in endothelial, smooth muscle and sweat gland cells. These inclusions were difficult to identifiy in one micron thick sections, emphazing the need of ultrastructural study for diagnostic purposes.
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  • 39
    ISSN: 1432-0533
    Keywords: Cytoplasmic tubular aggregates ; Electron microscopy ; Growth hormone cells ; Pituitary adenoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopy revealed the presence of cytoplasmic tubular aggregates in the capillary endothelium of a sparsely granulated growth hormone cell adenoma removed surgically from a 25-year-old female patient with acromegaly. To our knowledge, this is the second publication describing these structures in hypophysial growth hormone cell adenomas.
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  • 40
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    Acta neuropathologica 37 (1977), S. 95-100 
    ISSN: 1432-0533
    Keywords: Brain oedema ; Ouabain ; Na-K-ATPase ; Na-ion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ouabain, a specific inhibitor of active cation transport across cell membrane, was applied topically to brain surface of cats. The cerebral cortex to which 10−3 M ouabain was applied showed a spongy state, which was ultrastructurally revealed to be swelling of the neuronal cell processes, especially of dendrites. Astrocytes did not show swelling even in the most severely affected lesions. There was a marked increase in sodium with a slight increase of water in the most severely affected lesions. There was a marked increase in sodium with a slight increase of water in the cortex treated with 10−3 M ouabain. No evidence of increased vascular permeability was noted in the cortex, morphologically or biochemically. Electron microscopic cytochemistry to detect the sodium ion revealed that the increased sodium in the cortex accumulated in the swollen neuronal cell processes. It is speculated that neuronal rather than astrocytic elements might be highly dependent upon active cation transport, and that intracellular oedema in the brain tissue responsible for impairment of active cation transport might be related primarily to neuronal elements.
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  • 41
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    Acta neuropathologica 38 (1977), S. 39-43 
    ISSN: 1432-0533
    Keywords: Amyotrophic lateral sclerosis ; Muscle biopsy ; Target fibre ; Lamellar inclusions ; Transversal tubular system ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a muscle biopsy from a patient suffering about 2 years from an amyotrophic lateral sclerosis groups of atrophic fibres and target fibres were observed. By electron microscopic examination, amongst numerous parallel or spinal cisternae near the plasma membrane, single-membrane bound smooth tubular elements with a constant diameter of 200–300 Å occur in the central and intermediary zone of some target fibres. The connexion between these tubules and the terminal cisternae (triads) of the sarcoplasmic reticulum, suggest that this phenomenon seems to be a proliferation of the transversal-tubular system due to the partial denervation. Only a mechanical displacement of the T-tubules as a result of the destruction of the muscle fibres is not plausible, because the T-system volumetrically amounts only 0.3–0.5% of the muscle fibre.
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  • 42
    ISSN: 1432-0533
    Keywords: Human fetal muscle ; Electron microscopy ; Motor end-plate ; Extraocular muscles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The development of human extraocular muscles (EOM) was studied in a series of fetal specimens (12–24 weeks gestation). EOM were evaluated by enzyme histochemistry (EZ) (NADH and ATPase), by differential phase contrast microscopy (DPC) and electron microscopy (EM). In the early fetus (14 weeks), there was no clear-cut sub-division into fibre types. A uniform histochemical reaction was seen with NADH while ATPase showed light and dark myotubes. Myotubes contained large central nuclei, prominent eccentric nucleoli, abundant glycogen granules, free ribosomes, numerous mitochondria, and dense and looser bundles of myofilaments. Mesenchymal cells undergoing mitosis and fibroblasts with prominent stacks of rough endoplasmic reticulum were scattered within endomysium. Mast cells with well formed cytoplasmic granules were found as early as 18–24 weeks. The same specimens by DPC showed differentiation into at least 4 different fibre types at 12 weeks. All the intramuscular nerves at 12–16 weeks were composed of unmyelinated fibres. At 18 weeks, myelinated axons were present. Morphologically immature end-plates devoid of junctional folds were found at 12 weeks. The motor innervation of some EOM appears to be derived from more than one axon (multiple innervated fibres). At 18 weeks gestational age, differentiation into fibre types became apparent by enzyme histochemistry. These histochemical and morphological findings suggest that morphologically mature endplates are not prerequisites for differentiation into muscle fibre types.
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  • 43
    ISSN: 1432-0533
    Keywords: Resting microglia ; Silver impregnation ; Electron microscopy ; Hematogenous cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Vibratome sections of hippocampus of adult rabbits were stained by a modified Hortega's silver-carbonate method. Impregnated materials were examined by electron microscopy to decide fine-structural characteristics of the resting microglia. Comparing their characteristics with those of macrophages, we came to the following conclusions:(1) Impregnated resting microglia in the hippocampus of adult rabbits can be identified as cells having distinct fine structures. (2) Resting microglia are morphologically different from macrophages or their precursor cells, and therefore, seem not to be hematogenous cells sojourning in the normal brain parenchyma.
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  • 44
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    Acta neuropathologica 39 (1977), S. 177-180 
    ISSN: 1432-0533
    Keywords: Herpes simplex virus type II ; Organized CNS culture ; Cerebellar explants ; Electron microscopy ; Herpes infection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Organized cultures of newborn rat and hamster cerebellum were infected with herpes virus type II, after 7 and 14 days “in vitro”. 48 h after the infection, electron microscopic examination of the cultures showed that astrocytes contained numerous intranuclear and intracytoplasmic viral particles, while neurons remained apparently intact. The specificity of the infection for a given cell type is discussed.
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  • 45
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    Acta neuropathologica 39 (1977), S. 231-235 
    ISSN: 1432-0533
    Keywords: Actinomyces viscosus ; Epidural space ; Spinal cord ; Cat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a 3 year old female domestic cat a suppurative, granulomatous lesion of the tail and sacral area penetrated into the epidural space, causing paraplegia. A. viscosus was isolated from the inflammatory tissues. A comparative light and electron-microscopic study of the bacterial elements and the architecture of the granules (Drusen) show that the latter are in-vivo microcolonies of the agent.
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  • 46
    ISSN: 1432-0533
    Keywords: Metachromatic leukodystrophy ; Peripheral nerve ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural findings in nerve biopsies from two cases of late onset metachromatic leukodystrophy were compared with those in cases of late infantile and juvenile onset. Hypertrophic changes and regenerating clusters were more evident in the late onset cases, in which macrophages were less frequent, presumably reflecting the chronicity of the disorder in this form. Inclusions within Schwann cells and endoneurial macrophages were similar in all four cases. Myelin figures, in which the periodicity of major dense lines was 8 nm, were present in Schwann cells associated with myelinated axons. The electron lucent zones between the major dense lines were bisected by lines of lesser electron density. These inclusions were probably related to myelin breakdown. All other inclusions displayed a periodicity of 5.8 nm and consisted of zebra bodies, vacuoles containing irregularly orientated lamellar material and stacks of flattened discs. These inclusions represented the metachromatic sulphatide deposits. Occasional inclusion bodies were observed within axons.
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  • 47
    ISSN: 1432-0533
    Keywords: Spontaneously hypertensive rats ; Bilateral carotid occlusion ; Acute ischemic brain damage ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study of cerebral infarcts in spontaneously hypertensive rats 1–5 h after bilateral carotid artery occlusion was performed. The alterations of the neocortex consisted of shrinkage of the neurons surrounded by swollen astrocytic processes. Distension of the rough endoplasmic reticulum of the neuronal cytoplasm appeared early, while changes of the mitochondria were slight. Though there appeared slight to moderate perivascular astrocytic swelling, endothelial swelling was rare and there was no severe narrowing of the capillary lumen. There were no filling defects of colloidal carbon injected to the blood vessels of the ischemic brains. Ischemic neuronal alterations were proved to develop in the absence of severe morphological changes of the microvasculature in the developing cerebral infarcts in the present experimental model.
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  • 48
    ISSN: 1432-0533
    Keywords: Poxvirus group ; Vaccinia virus, neurovirulent ; Neurovaccinia strains ; Meningoencephalitis, experimental ; Virus morphogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adult NMRI mice were inoculated intracerebrally with 1.5–5×102 pfu of the “neurovirulent” strain Ma1 of vaccinia virus. The animals usually became diseased on day 3 and died on day 5 or 6 p.i. Infectivity assay studies on the mouse brains yielded a steeply rising viral titer comparable with that exhibited by several other so-called neurovaccinia strains after intracerebral inoculation. Histological studies revealed a patchy leptomeningitis most apparent over the basal brain surface. Mononuclear elements of varied size were the most common infiltrate cells in the meningitic lesions. These often showed a pronounced hemorrhagic and necrotizing character. In some places, the cellular infiltrates within the subarachnoid space extended along the perforating vessels into the superficial cerebral cortex. By electron microscopy, all essential stages of virus morphogenesis including the discharge of mature virions could be seen in numerous mononuclear phagocytes and adventitial cells. In contrast to this, no unequivocal neuroectodermal cell showed morphologic evidence of productive viral infection. Likewise, no endothelia or vascular myocytes were encountered which contained newly formed virus particles. However, alterations of the walls of blood vessels and signs of disturbed vascular permeability were a frequent finding in the meningeal foci of inflammation as well as in and around the track left by the inoculating needle. Another ultrastructural feature of the meningitic lesions was the widespread occurrence of degenerating or disintegrating infiltrate cells both infected and uninfected ones. The virologic and morphologic findings observed in this model of experimental vaccinia virus meningo-encephalitis are discussed with regard to data previously published by other authors. The propensity of strain Ma1 of vaccinia virus (and most probably of other so-called neurovaccinia strains) for replication in mesenchymal cells in particularly emphasized.
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  • 49
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    Acta neuropathologica 40 (1977), S. 73-77 
    ISSN: 1432-0533
    Keywords: Transplacental carcinogenesis ; Ethylnitrosourea ; Schwannomas ; Free cholesterol ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Malignant schwannomas of the trigeminal nerves were induced transplacentally by a single intravenous injection of 30 mg of N-ethyl-N-nitrosourea per kg of body weight into pregnant BD-IX rats on the 15th day of gestation. These neoplasms consisted of a pleomorphic population of Schwann cells and occasional fibroblasts. In order to preserve sterols the tumours were fixed in a digitonin-containing aldehyde solution. The electron microscope investigation of the tissues so treated revealed various structures: lamellar, tubular and complex formations were all observed. In addition, the unit membranes, including those of various cytoplasmic organelles, showed areas of increased contrast. The abundance of these fine structural configurations indicated the high sterol content of ethyl-nitrosourea-induced schwannomas.
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  • 50
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    Acta neuropathologica 38 (1977), S. 187-194 
    ISSN: 1432-0533
    Keywords: Fabry's disease ; Muscle biopsy ; Nerve biopsy ; Electron microscopy ; Lamellar bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A study of a muscle biopsy has provided evidence of storage involvement of the skeletal muscle fibres in Fabry's disease. In the endothelial cells of the capillaries, the inclusions were more abundant and pleomorphic. Muscle satellite cells were spared. In the sensory nerve biopsy, the perineurial and endothelial cells contained lamellar bodies, but not the Schwann cells. There was a slight reduction of the number of the small myelinated fibres and of the unmyelinated fibres. An electron microscopic study of a muscle biopsy can be helpful in the diagnosis of the disease. The physiopathology of the pain attacks is still a matter for discussion.
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  • 51
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    Acta neuropathologica 40 (1977), S. 163-169 
    ISSN: 1432-0533
    Keywords: Leucodystrophy ; Myelin ; Dog ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A recently recognised progressive disorder of central myelin in Dalmatian dogs is described. The disease is probably transmitted by autosomal recessive inheritance. The symptoms started at the age of 3–6 months and were dominated by visual deficiency and/or progressive locomotive abnormalities. Pathologically, the most consistent lesions were found bilaterally in the region of the centrum semiovale. The optic nerves were also frequently affected, the basal ganglia and spinal cord were affected infrequently. The main lesions were confined to myelin, while axons and nerve cells were spared, particularly in the early stages of the lesions. Numberous phagocytes were observed which contained engulfed myelin and other lipid breakdown products. Ultrastructurally and histochemically the disease differs from previusly described types of leucodystrophy.
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  • 52
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    Acta neuropathologica 40 (1977), S. 157-161 
    ISSN: 1432-0533
    Keywords: Tuberous sclerosis ; Electron microscopy ; Astrocytes ; Microvilli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A sporadic case of tuberous sclerosis in a stillborn infant is reported. The death at the 31st week of gestation was presumably due to the development of enormous rhabdomyomas of the heart. The typical cerebral lesions were fully developed as in patients deceased later in life. The atypical cells found in the cortical tubers demonstrated ultrastructural features of reactive astrocytes. Moreover, they showed innumerable microvillilike projections on their surface and junctional complexes, mostly of the zonula adhaerens type, reminiscent of ependymocytes. The significance of such glio-epithelial cellular features is discussed.
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  • 53
    ISSN: 1432-0533
    Keywords: Disulfiram psychosis ; Electron microscopy ; Synaptic changes ; Dopamine-β-hydroxylase ; Histotoxic anoxia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following chronic administration of disulfiram to rats, changes of the brain were examined electron-microscopically. Pathological findings were observed in the nerve cells of the cerebral cortex and hypothalamus at later stage, and synaptic changes in the hypothalamus from initial stage. On the other hand, changes of myelinated fibers, neuroglias and capillaries were very slight. It was considered that neurons were affected more predominantly than other neuronal elements by the cytotoxic action of the drug, and that the synaptic changes of the hypothalamus might reveal chronic disturbance of noradrenergic transmission by inhibition of dopamine-β-hydroxylase. These ultrastructural findings might relate to the pathogenic mechanism of the disulfiram psychosis.
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  • 54
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    Acta neuropathologica 39 (1977), S. 173-175 
    ISSN: 1432-0533
    Keywords: Parkinson's disease ; Lewy body ; Dense core vesicles ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a case of Lewy body disease incidentally found at autopsy, numerous dense core vesicles, 80–200 nm in diameter, were seen in the neuronal perikarya of the locus caeruleus. They were particularly numerous in the vicinity of the Lewy bodies. The change seems to occur at the early stage of Lewy body production and may represent an additional morphologic clue to abnormal catecholamine metabolism in Parkinson's disease.
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  • 55
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    Acta neuropathologica 37 (1977), S. 65-68 
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Neuropathology ; Down's syndrome ; Human cerebral cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a quantitative electronmicroscopic study, autopsy samples from the frontal and temporal lobes of two severely defective mongoloid brains were examined for the presence of abnormalities in the ultrastructure of the cerebral cortex. Particular attention was paid to the occurrence of atypical neuronal and glial inclusions similar to those which occur in small numbers (1 in 5000 µ2 of cortex) in neurologically normal brain (Rees, 1975). An area of 3.6×105 µ2 of cortex was examined from each brain. Within the cortical parenchyma, there was no gliosis, neuronal death or areas of degeneration. Atypical neuronal and glial inclusions were observed in both of the retarded brains, but they did not occur in substantially different numbers from normal brains. There were no inclusions or structural abnormalities peculiar to the retarded brains. Thus, in these two defective brains, it has not been possible to demonstrate any specific abnormalities in the ultrastructure of the cortex.
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  • 56
    ISSN: 1432-0533
    Keywords: Lymphocyte ; Juvenile amaurotic idiocy ; Ceroid lipofuscinosis ; Vacuolar contents ; Electron microscopy ; Sural nerve ; Muscle ; Rectum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lymphocytes of the peripheral blood of 31 patients with juvenile amaurotic idiocy (juvenile form of ceroid lipofuscinosis) were examined with the electron microscope. In all cases, intracytoplasmic clear vacuoles were present, containing round hollow, fingerprint and highly electron dense structures. The combination of these structures, not necessarily in one and the same vacuole, was considered to be highly indicative for the diagnosis of juvenile amaurotic idiocy. In addition to these three structures, parallel tubular inclusion bodies, rectilinear profiles and rodshaped structures were found but in a number of the cases. The parallel tubular inclusion bodies were not regarded as having any diagnostic significance.
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  • 57
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    Acta neuropathologica 37 (1977), S. 213-217 
    ISSN: 1432-0533
    Keywords: Peripheral neuropathy ; Giant axons ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An 8-year-old boy with a slowly progressive motor neuropathy is described. The first signs appeared at the age of 3 years. Histological examination of the sural nerve showed the presence of numerous segmental axonal swellings and features of demyelination as well as remyelination. These enlargements were filled with irregularly orientated 10 nm filaments. The case resembled the previously described cases of giant axonal neuropathy but differed from them in absence of kinky hair.
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  • 58
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    Calcified tissue international 23 (1977), S. 215-223 
    ISSN: 1432-0827
    Keywords: Amorphous mineral ; Bone ; Electron microscopy ; Ultracryotomy ; Ultramicro-incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The fine structure of the extracellular phase of avian medullary bone and embryonic chick femur was examined in thin sections prepared by ultracryotomy and ultramicroincineration. Since contact with solutions was completely avoided, little or no loss or dislocation of mineral constituents could occur. Amorphous bone mineral (ABM) was present in two forms: as 15–30 nm spheres and as a structure-free haze. Removal of all organic material by low temperature ashing left the ABM intact. Crystals were usually associated with the ABM. In newly ossifying regions clusters or nodules of randomly oriented crystals and ABM appeared to coalesce when they reached approximately 1 μm in diameter. In highly calcified regions crystals appeared to be oriented along collagen fibers. ABM did not appear to be associated with collagen. Unmineralized collagen was visible in osteoid after staining with dry OsO4 vapor and it appeared to be diverted around nodules. Structures which resembled matrix vesicles were present. Selected area electron diffraction patterns indicated the presence of hydroxyapatite.
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  • 59
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    Calcified tissue international 24 (1977), S. 191-197 
    ISSN: 1432-0827
    Keywords: Amelogenesis imperfecta ; Hypocalcification ; Hypoplasia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary An ultrastructural study of teeth with amelogenesis imperfecta revelaed various aspects of microcavities in the enamel surface, which ranged from isolated imprints of ameloblasts corresponding to the mildest lesions at the end of amelogenesis, to pits caused by the death of 20 to 30 ameloblasts at the beginning of amelogenesis. Abnormalities in the shape of the prisms can be observed. Further, crystals are distributed randomly within a prism or at the junction of 2 contiguous prisms while intercrystalline spaces are widened, indicating in various places the lack of a preferred orientation of the crystals. In amelogenesis imperfecta, two different crystalline periods are found: 1 of about 250 Å, the other of about 500 Å and over. The fact that amorphous areas are found among the crystals of enamel may be related to different stages of crystallization. However, it was not possible to find any lattice defect.
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  • 60
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    Calcified tissue international 24 (1977), S. 239-242 
    ISSN: 1432-0827
    Keywords: Cementum ; Lysis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Examination of microradiographs from the deciduous teeth of pigs revealed large lacunae or radiolucent zones close to the cemento-dentinal junction. Electron microscopic studies of the ground sections showed areas or irregularly shaped zones devoid of mineral and filled with collagen fibers. In the wide unmineralized zones, spherical clusters of crystallites were noted. Several cementum lacunae bordered by a broad rim of unmineralized collagen fibers were noted and some lacunae also contained zones of a moderately electron dense material. This material did not yield a diffraction pattern, while the mineralized part of the cementum gave the diffraction pattern typical of hydroxyapatite.
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  • 61
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    Experimental brain research 28 (1977), S. 133-139 
    ISSN: 1432-1106
    Keywords: Intralaminar nuclei ; Visual cortex ; Horseradish peroxidase ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thalamic projections to the visual cortex were investigated using the Horseradish peroxidase tracing technique. Besides confirmation of a distinct origin of thalamic projections to striate and extra-striate visual cortex, afferents of the intralaminar nuclei (ILN) to visual cortex were demonstrated. These projections of ILN were shown to be specific in that they terminate in areas 18, 19 and Clare Bishop but not area 17. The coupling of these intralaminar projections on to the extra-striate visual system is considered with respect to orientation of gaze.
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  • 62
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    Experimental brain research 28 (1977), S. 249-257 
    ISSN: 1432-1106
    Keywords: Hemilabyrinthectomy ; Compensation ; Postural deficits ; Vision ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A photographic technique was used to study the evolution of lateral head-tilt following hemilabyrinthectomy in adult cats. Animals were maintained post-operatively in normally lit conditions (LM cats), in total darkness (DM cats), or in stroboscopic light. In LM cats, the head tilt peaked at 45 degrees (with the lesionned side down) on the second post-operative day, and decreased to about 0 degree within about 10 days. This evolution was followed by rebounds of head-tilt to larger angles before a stable compensated head position could be maintained (approximately at the end of the third post-operative month). In DM cats, the head remained tilted by a large angle throughout the duration of the dark period. Re-exposure to light was followed by a rapid decrease of head-tilt. In stroboscopic light, the evolution of head-tilt was found to be closely similar to that in the normally lit condition. Finally, when put back in the dark at a late post-operative stage, already compensated animals were found to loose their symmetrical head position, and to re-acquire a strong head tilt. This effect resumed on re-exposure to light. It is inferred that static visual input is a necessary condition for compensation of the postural deficits of hemi-labyrinthectomy in the cat. Maintenance of a stable head posture also depends upon continuous availability of visual input.
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  • 63
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    Experimental brain research 28 (1977), S. 345-361 
    ISSN: 1432-1106
    Keywords: Putamen ; Cat ; Center median parvocellular neurons ; Ultrastructure ; Degenerated boutons (type VII and IV)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cat putamen contains the identical nine types of synapses and the same proportion of axo-dendritic (or axo-somatic) synapses as described for the fundus striati. However, type III (cortico-striatal) (31∶16%) and type V (axon-collateral) (13∶1%) occur much more frequently and type I (nigro-striatal) much less frequently (14∶34%) in the putamen than in the fundus striati. Of the axo-spinous synapses only type IV, with densely arranged small round vesicles and interrupted, asymmetric contact, shows a dark degeneration after center median lesions, mainly in the parvocellular part. Of the six axo-dendritic (or axo-somatic) synapses, only type VII, with densely packed small round vesicles and asymmetric contact, is degenerated after the same lesion in the center median nucleus. However, after such lesions type VII synapses are much more frequently degenerated in the putamen than those of type IV.
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  • 64
    ISSN: 1432-1106
    Keywords: Pontine nuclei cells ; Unitary EPSPs ; Synaptic organization ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Intracellular potentials of pontine nuclei (PN) cells were recorded in cats anesthetized with pentobarbitone sodium. 2. Stimulation of the cerebellar nuclear regions or the brachium pontis induced an antidromic action potential composed of IS-SD spikes, after-depolarization and after-hyperpolarization. 3. Cerebellar stimulation produced EPSPs only in a few PN cells. 4. Activation of the corticopontine or pyramidal tract produced in all PN cells an EPSP built up from the unitary components with variable amplitudes and time courses. Paired or repetitive activation revealed a property of the frequency potentiation of the EPSP. 5. Unitary EPSPs also occurred spontaneously. A great majority of these spontaneous EPSPs were cerebral in origin, and had amplitudes and time courses comparable with those evoked by stimulation of the corticopontine or pyramidal tract. 6. The half-width versus time to peak relationship of these unitary EPSPs suggested a dendritic location of the synapses with variable distances from the soma. It is assumed that large, proximal synapses serve for efficient relay of signals while small, distal synapses for their integration.
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  • 65
    ISSN: 1432-1106
    Keywords: Lateral geniculate nucleus ; Cat ; Dark adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The responses of neurones in laminae A and A1 of the cat lateral geniculate nucleus to moving stimuli were investigated at different background luminances. Moving bright slits, dark bars and edges were employed; the contrast of stimuli against the background was held constant. Background intensities varied from 10−3 to 102 td. Responses as stimuli passed across the centres of LGN receptive fields became stronger with increasing levels of light adaptation up to 10−1–101 td and then remained constant. Responses as stimuli passed through surround regions altered qualitatively with adaptation level, generally increasing in strength and complexity with background luminance. As a bright slit for on-centre cells or dark bar for off-centre cells left the surround, in almost all units a strong secondary peak could be elicited by an appropriate selection of the adaptation conditions. Many features of the responses to moving stimuli could not be predicted from the responses to stationary stimuli under different adaptation conditions described in the previous paper.
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  • 66
    ISSN: 1432-1106
    Keywords: Cat ; Visual cortex ; Intrinsic connections ; Degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The extent of the spread of axonal degeneration was investigated in the visual cortex of the cat after making small lesions restricted to the grey matter. Two series of experiments were undertaken. In the first, normal adult cats were used, and in the second, the cortex of the postlateral gyrus was isolated from its extrinsic afferents by surgical undercutting 3 months before making the lesions. The results were similar in the two series in most respects. 1. Horizontal fibres extended in considerable numbers for some 500 μm from the lesion, mainly in layers I, III/IV and V, a few reaching 2–3 mm. These fibres were better seen in the intact than in the isolated cortex. Their spread was usually asymmetrical, being greater posteromedially than anterolaterally. 2. Oblique axons ran downwards from the middle layers into layers V and VI, or upwards into layers I and II. 3. Axons arising from layers II to VI descended vertically into the white matter. Degeneration patterns after lesions in areas 17 and 18 were compared.
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  • 67
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    Experimental brain research 28 (1977), S. 21-35 
    ISSN: 1432-1106
    Keywords: Cat ; Visual cortex ; Binocular convergence ; Ocularity stripes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The average latency of cortical neuronal responses to electrical optic nerve (ON) stimulation was 3.0±0.7 s.d. msec. No significant difference between latencies to ipsi- and contralateral ON stimulation was found. Binocularly excitable cells showed almost equal response latencies to stimulation of both nerves. The average latency of subcortically recorded geniculo-cortical fibers was 0.3 msec less, but showed the same variance as that of cortical cells, suggesting that in all cases direct monosynaptic excitation of cortical cells by fibers of either ocularity is possible. Classes of ocular dominance based on electrical stimulation were positively, but not 100% correlated with classes of ocular dominance to visual stimulation. An anatomical study revealed that in cat terminals of geniculo-cortical projection are segregated to a lesser degree into ocularity stripes than in monkey. Direct monosynaptic excitation of cells by fibers of either ocularity which was found physiologically would also on these grounds appear possible for all cells.
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  • 68
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    Experimental brain research 29 (1977), S. 429-432 
    ISSN: 1432-1106
    Keywords: Visual movement perception ; Cat ; Contrast sensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Behavioral experiments show that the visual system of cat contains mechanisms which are selective for direction of stimulus movement. The cat's contrast detection threshold for a drifting grating is unaffected by the addition of a grating moving in the opposite direction; this same pattern of results is found for human observers. The convergence of cat and human psychophysical data suggests that man's brain may hold direction-specific neurons, similar to those known to exist in the cat brain.
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  • 69
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    Experimental brain research 30 (1977), S. 25-41 
    ISSN: 1432-1106
    Keywords: Cat ; Visual cortex ; Deprivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of monocular deprivation from contour vision were investigated in the striate cortex of cats. In addition to the receptive field (RF) properties of single cells responses to electrical stimulation of the deprived and the experienced optic nerve were analyzed: Evoked potentials as well as intra- and extracellularly recorded single unit responses were evaluated. The main goals were: 1. to determine to what extent the responses to electrical stimulation reflected the shift in ocular dominance apparent from the RF analysis, 2. to determine the relative effects of deprivation on excitatory and inhibitory responses and 3. to locate the site of impaired transmission in the pathway from the deprived eye. The results show that the responses to electrical stimulation reflect precisely the shift in ocular dominance apparent from the RF analysis. The evoked potentials elicited from the deprived nerve further indicate that deprivation had also affected the afferent system at the LGN level or (and) at the terminal field of the thalamo-cortical fibers. In contrast to the reduction of short latency excitatory responses to stimulation of the deprived nerve, oligosynaptic inhibition with latencies of 4–6 msec was equally well elicited by stimulation of either eye. The same was true for delayed excitatory responses which frequently occur with latencies between 40 and 80 msec after nerve stimulation. It is concluded from these results 1. that transmission between thalamic afferents and inhibitory interneurones in the cortex is less affected by deprivation than transmission in those pathways which relay cortical excitation, 2. that there is another deprivation resistant indirect pathway from the retina to the visual cortex which is probably relayed through mesencephalic structures and 3. that deprivation effects are not confined to transmission failure at the thalamo-cortical synapses but include alterations already at the presynaptic level.
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    Experimental brain research 27 (1977), S. 101-111 
    ISSN: 1432-1106
    Keywords: Eye muscle afferents ; Stretch receptors ; Cerebellar cortex ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Extraocular proprioceptive input to cerebellar vermis, lobule VI, was investigated in cats under N2O analgesia by recording neuronal responses to eye muscle stretch. Both optic tracts were transected and the periorbital skin and conjunctiva were locally anaesthetized. Eye rotation within the physiological range was achieved by applying a pull of predetermined length and tension to each of the eight musculi recti at their insertion to the globe. Within lobule VI, only small patches of cortex receive stretch receptor afferents. The information made available by these afferents corresponds to a change of eye position. Minimal responses were dependent upon angular deflections of a few degrees. Maximal response amplitudes were obtained within the physiological range of angular deflections and angular velocities for the units tested. Most cells responded to stretch of more than one muscle. Three types of convergence were found: (1) neurons responding according to a certain direction of a conjugated movement of both eyes, (2) neurons responding to movements in either direction of one plane, (3) more complicated response patterns.
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  • 71
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    Experimental brain research 28 (1977), S. 235-248 
    ISSN: 1432-1106
    Keywords: Vestibulo-ocular reflex ; Hemilabyrinthectomy ; Role of vision ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. A new description of vestibulo-ocular responses to angular velocity steps has been used to quantify vestibular compensation in right hemilabyrinthectomized cats. The amplitudes (VM and CM) and the times of occurrence (tM and to) from stimulus onset of the peaks of slow phase eye velocity and slow cumulative eye position were computed for velocity steps directed towards the lesioned side (clockwise, CW) and towards the intact side (counterclockwise, CCW). In addition, the values of these parameters were corrected from the effects of spontaneous nystagmus, when present. 2. In animals recovering in normal laboratory conditions, spontaneous nystagmus disappeared within 10 days after operation. In CCW responses, vm decreased by about 45% during the first 3 days and then remained stationary during the next 2 weeks. In CW responses VM showed a rapid increase during the first 3 days, and then remained stationary. After 2 weeks, VM increased in both CW and CCW responses. CM changes substantially reproduced those of VM. 3. In animals put in the dark immediately after operation, spontaneous nystagmus persisted until re-exposure to light (up to 31 days) and then disappeared rapidly. VM in both CW and CCW responses remained at a low value during the dark period and became more or less doubled after one week of exposure to light. CM also increased rapidly in CW and CCW responses, after re-exposure to light. 4. In the discussion these results are compared with those concerning activity of single vestibular neurons during compensation. It is concluded that vision is a primary factor conditioning disinhibition of vestibular nuclei spontaneous activity after the critical phase of compensation.
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  • 72
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    Experimental brain research 28 (1977), S. 421-425 
    ISSN: 1432-1106
    Keywords: Visual system ; Cat ; Proprioceptive receptors ; Extraocular muscles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electrical stimulation of the intraorbital part of the motor branches of extraocular muscles, where proprioceptive fibers run, evokes responses in 25% of the units of the striate cortex of the cat. The latency ranges between 25 and 40 msec. Mechanical stretch of extraocular muscles evokes multiunit responses in the striate cortex. The response is abolished by injection of xylocaine into the stretched muscle. The suppression of the response is reversible.
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  • 73
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    Experimental brain research 27 (1977), S. 335-345 
    ISSN: 1432-1106
    Keywords: Spatial frequency ; Visual neurones ; Mean luminance ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experiments have been performed on unanaesthetized and paralysed cats. The tuning curves for spatial frequency of retinal, lateral geniculate and simple and complex cells of the cortex have been determined in response to sinusoidal gratings of various spatial frequencies at different levels of mean luminance. For all neurones, decreasing the mean luminance leads to a progressive loss of spatial resolution and contrast sensitivity. Retinal ganglion cells of type X show, for scotopic levels of luminance, a flattening of their spatial frequency tuning curves in the low spatial frequency range. For geniculate and cortical neurones, on the contrary, the spatial frequency characteristics at the various levels of luminance remain practically invariant in their bandwidth. On the average, complex cells still respond to mean luminances ten times lower than simple cells. The tuning curves for orientation of cortical cells maintain, to a first approximation, the same shape at the various levels of mean luminance. The results are discussed, comparing the electrophysiological with psychophysical data.
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  • 74
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    Pflügers Archiv 369 (1977), S. 27-32 
    ISSN: 1432-2013
    Keywords: Electrodermal reflexes ; Natural stimulation of skin ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Electrodermal reflexes recorded from the central pads on the hind- and forepaws were elicited by natural stimulation of skin in ketamine anaesthetised cats. 2. Stimuli which excite the Pacinian corpuscles in the paws (air jet stimuli applied to the paw, vibrational stimuli produced by tapping on the experimental frame) and the cutaneous nociceptors (mechanical and thermal noxious stimuli) elicit electrodermal reflexes. Stimuli exciting hair follicle receptors on the trunk or legs or slowly adapting receptors in the feet are without effect. 3. Electrodermal reflexes elicited by non-noxious mechanical stimulation of skin in the hindpaws have a clear-cut spatial organization. Air jet stimuli can only produce them from the distal hindpaws but not from any other skin area indicating that this reflex may be organized at the spinal level. Electrodermal reflexes on noxious stimulation too have some spatial organization.
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  • 75
    ISSN: 1432-2013
    Keywords: Vasoconstrictor neurones ; Skin ; Muscle ; Systemic hypoxia ; Systemic hypercapnia ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Reactions of cutaneous and muscle vasoconstrictor neurones to the hindlimb on systemic hypoxia and systemic hypercapnia were investigated in chloralose anaesthetized cats. Mainly four types of preparations were used: brain intact and decrebrate (pontomedullary) animals with and without cartotid sinus (CSN) and vagal nerves (VN). 2. In brain intact animals with intact CNS and VN most cutaneous vasoconstrictor neurones were depressed and most muscle vasoconstrictor neurones were excited during systemic hypoxia and hypercapnia. The responses to hypercapnia were smaller than those to hypoxia. 3. In brain intact deafferented animals and in decerebrate animals with and without intact CSN and VN systemic hypoxia and hypercapnia induced excitation in both cutaneous and muscle vasoconstrictor neurones. The responses to hypoxia were significantly smaller in deafferented preparations when compared to those in preparations with intact CSN and VN. Furthermore in muscle vasoconstrictor neurones the size of the responses was not significantly different in decerebrate preparations from that in brain intact preparations. 4. These results indicate a distinct neuronal organization of the chemoreceptor reflexes in the vasoconstrictor systems in the brain stem. Suprapontine brain structures are most important for producing the inhibition of the cutaneous vasoconstrictor neurones during hypoxia and hypercapnia.
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  • 76
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    Journal of molecular medicine 55 (1977), S. 1137-1147 
    ISSN: 1432-1440
    Keywords: Edema ; Capillary permeability ; Pericardial effusion ; Microcirculation ; Electron microscopy ; Ödem ; Kapillarpermeabilität ; Perikarderguß ; Mikrozirkulation ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 2 Patientinnen hatten neben dem Krankheitsbild der idiopathischen Ödeme Höhlenergüsse insbesondere des Perikards. In dem einen Fall erforderte der große Perikarderguß schließlich die Perikardresektion, im anderen Fall führte Spironolacton-Dauerbehandlung zur weitgehenden Normalisieriung. Der relativ hohe Eiweißgehalt von Ödem (25 und 12 g/l) und Perikarderguß (55–61 und 48 g/l) und der vergrößerte Verteilungsraum für markiertes Eiweiß sprechen für vermehrte Permeabilität von kleinen Gefäßen und Grenzflächen für Eiweiß. Das Blutvolumen war niedrig normal bzw. erniedrigt. Elektronenoptisch fanden sich an den Hautgefäßen abnorme endotheliale Protuberanzen und große intercelluläre Lücken (Gaps) und an den Muskelgefäßen Befunde, die für einen gesteigerten cytopemptischen Transport sprechen. Die elektronenmikroskopischen Befunde der beiden Patientinnen zeigen keine prinzipiellen Unterschiede; sie stellen offenbar das morphologische Substrat gesteigerter Eiweißpermeabilität der Gefäße und der Bildung relativ eiweißreicher Ödeme dar. Damit sind morphologische Veränderungen bei Menschen mit idiopathischen Ödemen nachgewiesen, wie sie bisher nur in Tierversuchen mit experimentell erzeugten Ödemen beobachtet wurden.
    Notes: Summary Clinical and electron microscopic studies of two female patients are reported who, in addition to the symptoms and signs of idiopathic edema, had pericardial (and pleural) effusions. In one patient pericardiectomy had to be performed, in the other patient pharmacotherapy with spironolactone was effective. In these patients the protein-concentrations of edema fluid (25 and 12 g/l) and pericardial fluid (55–61 and 48 g/l) were relatively high; the distribution space of labelled protein was increased; blood volumes were low-normal or decreased. Electronmicroscopy of the microvasculature showed identical alterations in both cases. In the cutaneous vessels the endothelium developed numerous abnormal cytoplasmic processes and intercellular “gaps”. In the capillaries of skeletal muscle our findings indicate an increase in vesicular transport. We suggest the electron microscopic alterations to be the morphologic correlate for the increased transport and extravascular accumulation of protein. Changes as they are described here in humans with idiopathic edema have been documented before in animals with experimental edema.
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  • 77
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    Journal of neurology 215 (1977), S. 81-90 
    ISSN: 1432-1459
    Keywords: Spinal nerve root ; Cauda equina ; Transsection and suture ; Regeneration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Regeneration in dorsalen und ventralen Nervenwurzeln der Cauda equina nach Durchtrennung und Naht am Schwein wurde nach dreimonatiger Überlebenszeit untersucht. Obwohl keine detaillierten quantitativen Analysen durchgeführt wurden, konnte eindeutig festgestellt werden, daß die Regeneration in motorischen Wurzeln ausgiebiger was als in sensiblen Wurzeln. In den regenerierten Wurzeln wurde eine Zunahme von Histiozyten, Fibroblasten und Collagen sowie eine Verdickung der Wurzelhüllen beobachtet. In regenerierten dorsalen Wurzeln fanden sich heterotope, vom Myelon ausgewachsene Gliabündel.
    Notes: Summary The regeneration of nerve fibres in pigs was studied three months after transsection and end-to-end suture of the dorsal and ventral spinal nerve roots L 5 and S 1. Although no detailed quantitative analysis was performed, it was clearly evident that regeneration in motor roots is significantly more efficacious than in sensory roots. Probably as a reaction to Wallerian degeneration, an increase of histiocytes, fibroblasts and collagen fibrils, as well as a thickening of the sheaths was observed in the transsected and sutured roots. Heterotopic glial bundles were found in the regenerated dorsal roots.
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  • 78
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    Journal of neurology 215 (1977), S. 81-90 
    ISSN: 1432-1459
    Keywords: Spinal nerve root ; Cauda equina ; Transsection and suture ; Regeneration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Regeneration in dorsalen und ventralen Nervenwurzeln der Cauda equina nach Durchtrennung und Naht am Schwein wurde nach dreimonatiger Überlebenszeit untersucht. Obwohl keine detaillierten quantitativen Analysen durchgeführt wurden, konnte eindeutig festgestellt werden, daß die Regeneration in motorischen Wurzeln ausgiebiger was als in sensiblen Wurzeln. In den regenerierten Wurzeln wurde eine Zunahme von Histiozyten, Fibroblasten und Collagen sowie eine Verdickung der Wurzelhüllen beobachtet. In regenerierten dorsalen Wurzeln fanden sich heterotope, vom Myelon ausgewachsene Gliabündel.
    Notes: Summary The regeneration of nerve fibres in pigs was studied three months after transsection and end-to-end suture of the dorsal and ventral spinal nerve roots L 5 and S 1. Although no detailed quantitative analysis was performed, it was clearly evident that regeneration in motor roots is significantly more efficacious than in sensory roots. Probably as a reaction to Wallerian degeneration, an increase of histiocytes, fibroblasts and collagen fibrils, as well as a thickening of the sheaths was observed in the transsected and sutured roots. Heterotopic glial bundles were found in the regenerated dorsal roots.
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  • 79
    ISSN: 1432-1459
    Keywords: SMON ; Muscle biopsy ; Electron microscopy ; Neuromuscular junction ; Paracrystalline inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ein 46jähriger Mann, welcher über lange Zeit hohe Dosen von Clioquinol einnahm, entwickelte recht plötzlich charakteristische neurologische Ausfälle, entsprechend einer subakuten myelooptischen Neuropathie (SMON). Bei der elektronenoptischen Untersuchung einer Muskelbiopsie, die 5 Monate nach Beginn der Erkrankung entnommen worden war, zeigten sich ausgeprägte degenerative Veränderungen der präsynaptischen Nervenendigungen und vereinzelte parakristalline Einschlüsse in der Endplattenregion, die einmalig erscheinen. Letzteres könnte das morphologische Substrat der toxischen Substanz darstellen, die für den SMON verantwortlich gemacht wird.
    Notes: Summary A man, aged 46, who had been taking Clioquinol in high doses for a long period, developed a characteristic neurological syndrome of subacute myelo-optic neuropathy rather abruptly. Electron microscopical examination of the muscle biopsy, obtained five months after the onset of the disease, revealed severe degenerative changes of the presynaptic nerve endings and some unique paracrystalline inclusions in the sole plate region. The latter may represent the morphological expression of the toxic agent which is held responsible for the subacute myelo-optic neuropathy.
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  • 80
    ISSN: 1432-1459
    Keywords: SMON ; Muscle biopsy ; Electron microscopy ; Neuromuscular junction ; Paracrystalline inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ein 46jähriger Mann, welcher über lange Zeit hohe Dosen von Clioquinol einnahm, entwickelte recht plötzlich charakteristische neurologische Ausfälle, entsprechend einer subakuten myelooptischen Neuropathie (SMON). Bei der elektronenoptischen Untersuchung einer Muskelbiopsie, die 5 Monate nach Beginn der Erkrankung entnommen worden war, zeigten sich ausgeprägte degenerative Veränderungen der präsynaptischen Nervenendigungen und vereinzelte parakristalline Einschlüsse in der Endplattenregion, die einmalig erscheinen. Letzteres könnte das morphologische Substrat der toxischen Substanz darstellen, die für den SMON verantwortlich gemacht wird.
    Notes: Summary A man, aged 46, who had been taking Clioquinol in high doses for a long period, developed a characteristic neurological syndrome of subacute myelo-optic neuropathy rather abruptly. Electron microscopical examination of the muscle biopsy, obtained five months after the onset of the disease, revealed severe degenerative changes of the presynaptic nerve endings and some unique paracrystalline inclusions in the sole plate region. The latter may represent the morphological expression of the toxic agent which is held responsible for the subacute myelo-optic neuropathy.
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  • 81
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    Journal of neurology 215 (1977), S. 103-114 
    ISSN: 1432-1459
    Keywords: Hypothyroidism ; Peripheral neuropathy ; Nerve biopsy ; Electron microscopy ; Renaut bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es werden die klinischen Daten und Nervenbiopsiebefunde von 4 hypothyreotischen Patienten, die Symptome einer diffusen peripheren Neuropathie aufwiesen, dargestellt. Klinisch-neurologisch bestanden sensiblen Reizzeichen von scherzhaftem Charakter, eine symmetrische, distale Sensibilitätsminderung mit Ataxie und eine Abschwächung der Muskeleigenreflexe mit Verlust der Achillessehnenreflexe. Bei einem Patienten war die periphere Neuropathie Leitsymptom der zugrunde liegenden metabolischen Erkrankung. Als Substrat dieser Ausfälle fand sich bei der licht- und elektronenmikroskopischen Untersuchung der N. suralis-Biopsien eine deutliche Verminderung der Markfasern, besonders die großkalibrigen, dickbemarkten Axone betreffend. Die Histogramme zeigten entsprechend ein pathologisches unimodales Faserspektrum. Dystrophische und degenerative Veränderungen an Axonen aller Faserklassen und das Vorkommen sogenannter „Regenerationsgruppen“ kleiner, dünnbemarkter Fasern deuten darauf hin, daß der Neuropathie bei diesen hypothyreotischen Patienten in pathogenetischer Hinsicht in erster Linie eine neuroaxonale Degeneration mit unvollständiger Regeneration zugrunde liegt.
    Notes: Summary Clinical and sural nerve biopsy findings are described in four hypothyroid patients with manifestations of a diffuse peripheral neuropathy. Clinical examination revealed distal sensory inpairment, complaints of burning and lancinating extremity pains, ataxia and a decrease of deep tendon reflexes with total ankle jerk loss. In one patient, signs of the peripheral neuropathy comprised the leading symptomatology of the underlying metabolic disorder. Light and electron microscopic investigations of the sural nerve biopsies revealed a marked reduction of myelinated fibers, affecting mainly the large myelinated axons. The histograms showed a pathological unimodal spectrum of myelinated fiber diameters. Dystrophic and degenerative changes in axons of all fiber classes and the presence of clusters of thinly myelinated small fibers suggest that neuroaxonal degeneration and incomplete regeneration may represent the major pathogenetic mechanism of the neuropathy in these hypothyroid patients.
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  • 82
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    Journal of neurology 215 (1977), S. 103-114 
    ISSN: 1432-1459
    Keywords: Hypothyroidism ; Peripheral neuropathy ; Nerve biopsy ; Electron microscopy ; Renaut bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es werden die klinischen Daten und Nervenbiopsiebefunde von 4 hypothyreotischen Patienten, die Symptome einer diffusen peripheren Neuropathie aufwiesen, dargestellt. Klinisch-neurologisch bestanden sensiblen Reizzeichen von scherzhaftem Charakter, eine symmetrische, distale Sensibilitätsminderung mit Ataxie und eine Abschwächung der Muskeleigenreflexe mit Verlust der Achillessehnenreflexe. Bei einem Patienten war die periphere Neuropathie Leitsymptom der zugrunde liegenden metabolischen Erkrankung. Als Substrat dieser Ausfälle fand sich bei der licht- und elektronenmikroskopischen Untersuchung der N. suralis-Biopsien eine deutliche Verminderung der Markfasern, besonders die großkalibrigen, dickbemarkten Axone betreffend. Die Histogramme zeigten entsprechend ein pathologisches unimodales Faserspektrum. Dystrophische und degenerative Veränderungen an Axonen aller Faserklassen und das Vorkommen sogenannter „Regenerationsgruppen“ kleiner, dünnbemarkter Fasern deuten darauf hin, daß der Neuropathie bei diesen hypothyreotischen Patienten in pathogenetischer Hinsicht in erster Linie eine neuroaxonale Degeneration mit unvollständiger Regeneration zugrunde liegt.
    Notes: Summary Clinical and sural nerve biopsy findings are described in four hypothyroid patients with manifestations of a diffuse peripheral neuropathy. Clinical examination revealed distal sensory inpairment, complaints of burning and lancinating extremity pains, ataxia and a decrease of deep tendon reflexes with total ankle jerk loss. In one patient, signs of the peripheral neuropathy comprised the leading symptomatology of the underlying metabolic disorder. Light and electron microscopic investigations of the sural nerve biopsies revealed a marked reduction of myelinated fibers, affecting mainly the large myelinated axons. The histograms showed a pathological unimodal spectrum of myelinated fiber diameters. Dystrophic and degenerative changes in axons of all fiber classes and the presence of clusters of thinly myelinated small fibers suggest that neuroaxonal degeneration and incomplete regeneration may represent the major pathogenetic mechanism of the neuropathy in these hypothyroid patients.
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  • 83
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    Archives of microbiology 113 (1977), S. 197-204 
    ISSN: 1432-072X
    Keywords: Gliding bacterium ; Simonsiella ; Oral cavity ; Electron microscopy ; Morphology ; Dorsal-ventral differentiation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The morphology and ultrastructure of the aerobic, Gram-negative multicellular-filamentous bacteria of the genus Simonsiella were investigated by scanning and transmission electron microscopy. The flat, ribbon-shaped, multicellular filaments show dorsal-ventral differentiation with respect to their orientations to solid substrata. The dorsal surface, orientated away from the substrate, is convex and possesses an unstructured capsule. The ventral surface, on which the organisms adhere and glide, is concave and has an extracellular layer with fibrils extending at right angles from the cell wall. The cytoplasm in the ventral region contains a proliferation of intracytoplasmic membranes and few ribosomes in comparison to the cytoplasm in other parts of the cell. Centripetal cell wall formation is asymmetrical and commences preferentially in the ventral region. Quantitative differences in morphology and cytology exist among selected Simonsiella strains. Functional aspects of this dorsalventral differentiation are discussed with respect to the colonization and adherence of Simonsiella to mucosal squamous epithelial cells in its ecological habitat, the oral cavities of warm-blooded vertebrates.
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  • 84
    ISSN: 1432-072X
    Keywords: Acetobacterium woodii ; Hydrogen-oxidizing acetate-forming anaerobe ; Fine structure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Acetobacterium woodii is a Gram-positive anaerobic nonsporeforming bacterium able to grow on H2 and CO2 as sole sources of energy. The product of fermentation is acetic acid. Fine structural analysis showed rod-shaped flagellated cells, and coccoid cells without flagella arranged predominantly in pairs and chains. The cell wall was found to be composed of three layers. The cell surface exhibited a periodic array of particles consisting of subunits. The cytoplasmic membrane showed particles either either in random distribution or in a hexagonal pattern. Intracytoplasmic membranes were rarely observed, whereas inclusion bodies of varying shapes, predominantly in an uncommon disc-shape, could frequently be observed. Their content was dissolved in ultrathin sections indicating hydrophobic nature.
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  • 85
    ISSN: 1432-072X
    Keywords: Defective lysogeny ; Alcaligenes eutrophus ; Simultaneous isolation technique ; Temperate bacteriophages ; Pseudomonas pseudoflava ; Biological characterization ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Widespread defective lysogeny was detected in Alcaligenes eutrophus by electron microscopic analysis of cultures. Mitomycin C treatment of the cultures resulted in the production of defective (inco-) particles. Polysheaths were produced both with and without induction. With the simultaneous isolation technique six phages were isolated for hydrogen-oxidizing strains of the new species Pseudomonas pseudoflava. The phages were able to replicate under autotrophic conditions and were found to have a very restricted host range. Electron microscopic analysis allowed classification into two structural groups. Group I contained phages with contractile tails; group II contained phages with flexible, noncontractile tails. All but one (gb) of the new phages were shown to be temperate by isolation of lysogens and induction with mitomycin C.
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  • 86
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    Archives of microbiology 112 (1977), S. 207-218 
    ISSN: 1432-072X
    Keywords: Cryptophyceae ; Algae ; Hemiselmis rufescens ; Chroomonas ; Cryptomonas ; Mitochondrial complex ; Cristae ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The unitary nature of the mitochondrion and the characteristic flattened finger-like morphology of the cristae were demonstrated in the Cryptophyceae. Hemiselmis rufescens contained an unbranched vermi-form mitochondrion in contrast to the variously branched complex, comprising an interconnected peripheral and central reticulum, in Chroomonas sp. and strains of Cryptomonas. The systematic value of the shape and distribution of the mitochondria in the examined genera was suggested.
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  • 87
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    Archives of microbiology 115 (1977), S. 185-198 
    ISSN: 1432-072X
    Keywords: Synechococcus lividus ; Cyanobacteria ; Carbon dioxide ; Electron microscopy ; Bleaching-regreening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of carbon dioxide on pigment and membrane content in Synechococcus lividus was studied by depriving cells of CO2 and examining cell populations biochemically and by electron microscopy. After 120 h of CO2 deprivation, S. lividus lost all detectable chlorophyll a and C-phycocyanin. Such bleached cultures were “mustard yellow”, the result of approximately 1.8 times more carotenoid per cell than green control cultures. Although cells from beached cultures appeared morphologically identical to control green cells when examined by light microscopy, electron microscopic examination revealed them to be devoid of detectable thylakoid membrane. Thylakoid membrane could not be recovered by physical isolation or revealed by freeze etching of bleached S. lividus. In addition, inclusion bodies characteristically found in S. lividus were also absent. Reintroduction of CO2 into bleached cultures resulted in a rapid resynthesis of both chlorophyll a and C-phycocyanin. Electron microscopic examination of these regreening cultures revealed that thylakoid membrane was also rapidly resynthesized. Growth of regreened cultures did not occur until there was the synthesis of a full complement of chlorophyll a, C-phycocyanin, and thylakoid membrane. A time course study of the cytological events occurring during bleaching and regreening is presented.
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  • 88
    ISSN: 1432-2013
    Keywords: Vestibular nuclei ; Cat ; Somatosensory integration ; Neck movement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The vestibular nuclei of cats were explored extracellularly with micropipettes to locate units with a resting discharge rate which responded to rotation in the horizontal plane. These units were examined for somatosensory input from neck and limbs. Fewer than half responded to somatosensory stimulation. The neck region was the body area most effective in influencing unitary activity. The response pattern most often noted was an increase and decrease in discharge frequency when the body was moved towards and away from the recording electrode respectively. Change in discharge rate was observed to be primarily dependant upon neck velocity and not upon absolute neck position. Half of the somato-sensory units received input from either the forelimbs or the hindlimbs, while the remaining half responded to both.
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  • 89
    ISSN: 1432-2072
    Keywords: Amphetamine ; Para-hydroxy-amphetamine ; Distribution ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The distribution and metabolic fate of amphetamine were studied in cats. In the brain, high levels of drug were detected in the grey matter structures at short intervals after administration, while at longer intervals distribution between white and grey matter areas was more uniform. In peripheral tissues the greatest concentration of the drug was seen in the highly vascularized organs. Para-hydroxyamphetamine was found in minimal amounts in the liver and kidneys and only at trace quantities in the brain.
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  • 90
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    Virchows Archiv 372 (1977), S. 287-297 
    ISSN: 1432-2307
    Keywords: Stomach ; Lipid islands ; Smooth muscle cells ; Foam cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Foam cells in lipid islands of the stomach can develop from both histiocytes and smooth muscle cells. With increasing storage of lipid vacuoles in smooth muscle cells, loosening of the myofilament arrangement and decrease of the dense areas subjacent to the plasma membrane occurs. Endoplasmic reticulum and the cisternae of the Golgi-apparatus dilate, the cell organelles increase initially and the basement membrane of the smooth muscle cells is fragmentarily formed. Only in incompletely formed foam cells can the origin from smooth muscle cells be recognised, in their final state their histiogenesis is seldom apparent.
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  • 91
    ISSN: 1432-2307
    Keywords: Myeloproliferative disorder ; Megakaryocytic-granulocytic myelosis ; Granulocyte lineage ; Bone marrow biopsy ; Freeze-fracture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 5 patients with chronic megakaryocytic-granulocytic myelosis (CMGM) bone marrow specimens were studied by electron microscopy to investigate possible abnormalities of the granulocytic cell lineage. Thin sections were compared with freeze-fracture replicas to elucidate further aspects of leucocyte cytology. The atypia exhibited in these cells (eosinophils, basophils and neutrophil granulocytes) consisted mostly of a disorganization of granulopoiesis with hyper- and hypogranulation, a pathological increase in the number of nuclear blebs and a maturation asynchrony sometimes leading to Pelger-like cell forms. Moreover, a presumptive stem cell was demonstrated in the erythopoietic and granulocytic cell lines resembling CFU cells. In conclusion, granulopoiesis in CMGM exhibited abnormalities as generally observed in chronic myelogenous leukaemia. When considered with our previous finding of malignancy in megakaryopoiesis, CMGM has to be classified as a myelosis of mixed cellularity.
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  • 92
    ISSN: 1432-2307
    Keywords: Vinylchloride-disease ; Splenomegaly ; Electron microscopy ; Enzyme histochemistry ; Morphometrics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Durch histometrische, enzymhistochemische und elektronenmikroskopische Untersuchungen konnte nachgewiesen werden, da\ die pathologischen MilzverÄnderungen bei der Vinylchlorid-Krankheit nicht durch hepatisch bedingte Pfortaderdruckerhöhung verursacht werden, sondern auf einer Gewebsalteration durch das Vinylchlorid oder dessen Metabolite beruhen. Dabei sind vor allem die faserbildenden Zellen der Milz beteiligt. Faserassoziierte Reticulumzellen in der roten Pulpa und fibroblastische Reticulumzellen in der wei\en Pulpa werden zu übermÄ\iger Bindegewebsneubildung stimuliert. Hierdurch kommt es in der roten Pulpa zur bindegewebigen Verödung der FiltrationsrÄume mit einer Reduzierung der Pulpastrangmakrophagen und in der wei\en Pulpa zu einer Vernarbung der periarteriellen Lymphscheiden. Die Folgen dieser Fibrosierungsprozesse sind charakteristische VerÄnderungen in der quantitativen Zusammensetzung der Gewebskomponenten, die sich deutlich von denjenigen in Milzen bei Lebercirrhose und Milzvenenthrombose unterscheiden.
    Notes: Summary By means of histometric, enzyme histochemical, and electron microscopic investigations it was demonstrated that the pathological changes in the spleen in vinylchloride-disease are primary. Fibroblastic cells are the only specific splenic cells involved. Fibre-associated reticulum cells of the red pulp and fibroblastic reticulum cells in white pulp are stimulated to produce excessive amounts of the extracellular elements of connective tissue, especially collagen fibrils. The newly formed connective tissue causes obliteration of extracellular blood channels in the red pulp and thus a reduction in the number of pulp-cord macrophages, and scarring of the periarterial lymphatic sheaths. The results of this fibrosing process are characteristic quantitative changes in the splenic histologic structures. These changes are different from those structural alterations occuring in spleens following extrasplenic hemodynamic changes, such as thrombosis of the splenic veins or cirrhosis of the liver.
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  • 93
    ISSN: 1432-2307
    Keywords: Thyroid gland ; Familial medullary carcinoma ; Morphogenesis ; Electron microscopy ; Cytochemistry of C-cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six cases of familial medullary thyroid carcinoma (MTC) were investigated by light and electron microscopy as well as by ultracytochemical methods. Light microscopic examination revealed multifocal C-cell proliferation in 5 subjects. These cells were mostly limited to thyroid follicles, but occasionally extended across the follicular capsule forming microscopic MTC. Electron microscopic examination showed that, in some follicles, the proliferating C-cells were still covered by a continuous layer of follicular cells, whereas in others the proliferation extended to the follicular center. C-cells were in direct contact with the colloid, and ultramicroinvasion of the follicular capsule was detected. These observations are consistent with the hypothesis that familial MTC seems to begin as multifocal C-cell proliferation, limited at first to thyroid follicles, between the capsule and the follicular epithelium. Later, the proliferation extends to the follicular center, and C-cells come in contact with the colloid, at which time an in situ carcinoma stage is reached. Some neoplastic cells invade the follicular capsule and, finally, multiple MTC appear and eventually conglomerate. Generally, there were no constant morphologic criteria for a dysplasia or neoplasia among the proliferating C-cells limited to thyroid follicles, when compared with normal or even malignant C-cells. For these reasons, a hyperplastic or dysplastic process preceding MTC cannot be clearly distinguished from a neoplastic process. Our study, however, shows that a light microscopic, apparently hyperplastic process may be a malignant one. Amyloid was present in the more voluminous MTC, associated with tumor cell necrosis, but it was not evident in small MTC and within the foci of C-cell proliferation. Ultracytochemical techniques revealed that the secretory granules of normal, proliferating and neoplastic C-cells contained polysaccharides and/or glycoproteins.
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  • 94
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 374 (1977), S. 275-284 
    ISSN: 1432-2307
    Keywords: Signet-ring cell ; Scirrhous carcinoma ; Gastric carcinoma ; Electron microscopy ; Stomach cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The signet-ring cells seen in gastric carcinoma of the diffuse type were studied by light and electron microscopy. A classification of these cells into Types A, B and C was developed, based on intracellular mucous granules, nuclei and organelles, and by reactions to PAS and Alcian-blue staining. The gradual transition of Type A cells to Type B and the subsequent change of Type B to Type C suggest successive stages in maturation. These cells, especially those of Type B, resemble the mucous neck cells of the corpus and the glands of the pylorus.
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  • 95
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 375 (1977), S. 257-262 
    ISSN: 1432-2307
    Keywords: Rabbit aorta ; Organ culture ; Endothelial regeneration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following an in vivo lesion of the rabbit thoracic aorta, endothelial regeneration was studied in silver-stained specimens from en face organ cultures of aortic segments with and without intercostal arteries. The in vivo lesion had been inflicted by an embolectomy catheter. Our results confirmed that endothelium regenerates from preexisting endothelium around the mounths of the intercostal arteries. A conspicuous observation was the orientation pattern of endothelial cells during regeneration. Transmission electron microscopy suggests that the cell cytoskeleton plays a role in the regulation of regeneration. The organ culture technique described, complementary to in vivo and in vitro investigations with cell cultures, seems to be a valuable tool in further investigations on factors involved in the repair of arterial tissue.
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  • 96
    ISSN: 1432-2307
    Keywords: Catecholamine ; Angiotensin ; Ouabain ; Dihydrotachysterol ; Rat heart ; Myocardial necrosis ; Electrolyte concentration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Noradrenalin und Angiotensin in hohen Dosen allein oder in Kombination mit Strophanthin appliziert, führen bei der Ratte zu einer Erniedrigung des Gesamtcalciumgehaltes des Myocard. Dihydrotachysterol (DHT) erhöht den Calciumgehalt und zeigt elektronenmikroskopisch SchÄdigungen an Mitochondrien und Myofibrillen. Die kombinierte Gabe von DHT und Noradrenalin bzw. Angiotensin potenziert den Calciumwert, erhöht das Magnesium und lÄ\t Kalium nahezu unverÄndert. Die im Bereich der linksventrikulÄren Innenschichten ausgebildeten „Catecholaminnekrosen“ finden sich nach DHT-PrÄmedikation ubiquitÄr. Strophanthin verhindert den massiven, durch DHT- und Angiotensinmedikation induzierten Calciumstieg, wÄhrend es bei der kombinierten Gabe von DHT und Noradrenalin keine Wirkung entfaltet. Myofibrillen und Mitochondrien sind verÄndert, Calciumablagerungen sind nachweisbar, charakteristische Unterschiede fehlen.
    Notes: Summary Changes in certain tissue electrolytes brought about by injecting rats with noradrenalin (NA), angiotensin or dihydrotachysterol (DHT) were compared with the concomitant ultrastructural alterations of cardiac muscle. High doses of NA or angiotensin given singly or together with ouabain were found to lower the overall myocardial calcium concentration without accompanying structural lesions. When calcium was increased more than tenfold by the administration of DHT, electronmicroscopy revealed altered myofibrils and mitochondria. Giving DHT along with NA or angiotensin not only preserved their calcium-lowering effect, but resulted in a massive increase in tissue calcium, with magnesium levels also rising, whilst the tissue content of potassium remained almost unchanged. Following NA administration the necrotic areas, known to be confined to the inner endocardial layer after catecholamine administration, pervaded the entire cardiac muscle mass. Ouabain prevented the massive rises of tissue calcium induced by DHT given together with angiotensin but was ineffective when added to the combination of DHT and NA. In either case, both myofibrils and mitochondria displayed ultrastructural alterations although distinctive features were lacking. The data suggests that DHT acts on cellular calcium, not only by mobilising calcium from osseous structures but also by interacting with intracellular calcium homeostasis. In addition to overstimulating contractile elements, calcium is thought to exert its noxious effect in a more generall way, e.g. by binding to surface membranes, thus affecting the normal functioning and eventually the structure of mitochondria and other organelles besides myofibrils.
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  • 97
    Electronic Resource
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    Springer
    Virchows Archiv 376 (1977), S. 165-174 
    ISSN: 1432-2307
    Keywords: Lung ; Electron microscopy ; Pulmonary alveolar proteinosis ; Degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopy in an infant of 4 months with pulmonary alveolar lipoproteinosis showed filling of the alveoli with osmiophilic lamellar bodies. Similar structures were present in the cytoplasm of type I alveolar epithelial cells and to a lesser extent in the capillary endothelium and interstitium. These changes represent widespread degenerative processes in the lung caused by an unidentified cytotoxic agent. In this patient the disease is comparable to the drug-induced cytotoxic animal model and differs from the dust-induced hypersecretory animal model.
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  • 98
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 176 (1977), S. 23-36 
    ISSN: 1432-0878
    Keywords: Lateral line organ ; Shark (Mustelus manazo) ; Neuromasts ; Cell types ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lateral line organ of the spotted shark is characterized by its semi-cylindrical shape. Each organ (neuromast) is so closely apposed to the next that the individual neuromasts are almost continuous. The neuromast is composed of receptor cells, supporting cells and mantle cells. The receptor cells bear one kinocilium and up to 40 stereocilia. Bi-directional arrangement of the receptor cells as occurs in teleosts was demonstrated. Afferent and efferent nerve endings were found at the base of the receptor cells. The supporting cells extend from the basal lamina to the free surface. Long microvilli and a cilium-like “ciliary rod” project from the top of each supporting cell. The cell contains relatively few elements of the Golgi apparatus and little rough endoplasmic reticulum, but mitochondria and filaments are abundant. The mantle cell limits the lateral margin of the neuromast. It is distinguished from the supporting cell because of its long crescent-shaped nucleus and scarce, short microvilli. Myelinated nerve fibres are found in the subepithelial connective tissue but not in the epithelium. The fine structure of the shark lateral line organ suggests that this organ is in an intermediated step of evolution between that of lamprey and teleost.
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  • 99
    ISSN: 1432-0878
    Keywords: OsO4 ; Cholesterol ; Symbiotes ; Aphids ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pea aphids left for 48 h in unbuffered osmium tetroxide show heavy staining of many organelles in the symbiote-containing cells (mycetocytes and sheath), embryos and oenocytes very similar to that characteristic of mammalian sterol-synthesizing cells. However, the staining of the pea-aphid cells is, to a large extent, dependent on the presence of cholesterol benzoate, or free cholesterol, in the aphid's diet. In aphids cultured in vitro with 3H mevalonate in the presence of added cholesterol, the incorporation of label into the cholesterol and lanosterol fractions is significantly reduced. If the dietary cholesterol effects a similar inhibition in vivo, the cholesterol-dependent osmium staining could be due to precursors(s) of cholesterol accumulating in the intracellular sites described. There is also osmium staining of large (normally electron-transparent) vacuoles in mycetocytes, gut and fat body, irrespective of dietary cholesterol.
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  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 176 (1977), S. 417-429 
    ISSN: 1432-0878
    Keywords: Fat body ; Galleria mellonella ; Basement membrane ; Ruthenium red staining ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fat body lobes of Galleria mellonella are surrounded by basement membrane — a fine granular layer of connective tissue. This membrane has an affinity for ruthenium red. The results obtained after treatment of the fat body with neuraminidase, hyaluronidase, phospholipase C and proteolytic enzymes suggest that glycoproteins and phospholipoproteins are constituents of this basement membrane. The basement membrane also has the ability to bind concanavalin A-peroxidase, which is associated with the presence of mannoside residues.
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