U Tauer

Leica Microsystems GmbH, Wetzlar, Hesse, Germany

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Publications (5)22.6 Total impact

  • R Wolter, U Tauer, E Fuchs, B Volk
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    ABSTRACT: The distribution of the major cytoskeletal components in frontal cryosections of the hippocampal formation of adult male tree shrews (Tupaia belangeri) was immunohistochemically investigated by using commercially available antibodies. Actin-immunolabeling was evident in all layers of the dentate gyrus as well as in the regio superior (CA1) and the regio inferior (CA3). Neurofilament 160 was detected only in the molecular layer of the dentate gyrus and in the axons of the granule cells (mossy fibers). For beta-tubulin, the microtubule associated proteins (MAPs) MAP2AB, MAP2ABC and Tau, immunoreactivity was evident within the granule cells and within the somatodendritic compartment of pyramidal neurons. Granule cells and the somata of the pyramidal neurons were intensely labeled for kinesin. Our findings show the elaborate expression of cytoskeletal proteins in the hippocampal formation of the tree shrew, relatively similar to what is seen in other species but with also some important differences, such as the immunonegativity of the axonal compartment for Tau in the tree shrew, which is contrary to what we see in the mouse (unpublished data). These findings provide useful insights regarding the organization of the hippocampal formation of the tree shrew and are fundamental for further research in this field.
    Journal of Chemical Neuroanatomy 11/1999; 17(2):65-74. · 2.48 Impact Factor
  • U Tauer, R Knoth, B Volk
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    ABSTRACT: In adult mice, administration of the anticonvulsive drug phenytoin caused focal swellings along the Purkinje cell axon correlated with ataxia and incoordination of movements. In our model, we used murine cerebellar slice cultures to study the influence of phenytoin on postnatal Purkinje cell axon differentiation. Almost all of our untreated cultures developed to mature-like cerebellar tissue. Immunohistochemistry with anti-calbindin-D28k or UCHTI (anti-CD3) antibodies revealed numerous Purkinje cell axons in the white matter. In the area of the deep cerebellar nuclei, immunolabelled axons formed a large axonal plexus. The few neurofilament-positive neurons in this area were densely covered with Purkinje cell axon terminals. The synaptophysin immunoreactivity revealed connections between the terminals and the neurons of the deep cerebellar nuclei. Treatment of cerebellar slice cultures with phenytoin (10-80 microM) for 10-16 days resulted in focal swellings of different size along the axon. The number of swellings increased with an increasing dosage. At concentrations of 40 microM phenytoin, Purkinje cell axons seemed to be unable to invade the deep cerebellar nuclei, but numerous aberrant, recurrent collaterals could be detected immunohistochemically with the two specific Purkinje cell antibodies. Possible cytotoxic effects after treatment, such as dendritic degeneration and a decrease in the number of immunolabelled Purkinje cells, were observed above 40 microM phenytoin. These data suggest that the response of juvenile Purkinje cells is dependent upon the dosage of the antiepileptic drug because of morphological alterations as well as a misrouting of previously established connections.
    Acta Neuropathologica 07/1998; 95(6):583-91. · 9.73 Impact Factor
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    ABSTRACT: Magnetic resonance imaging of amputated human knees was performed to determine optimal sequences for depicting articular cartilage. 24 knees were examined with eight different sequences in a 1.0 T imager. Each cartilage lesion was graded from 1 to 4 (Outerbridge staging system). The results of each sequence were compared with the macroscopic findings and statistically tested against each other. The FLASH sequence (TR = 50 ms) with combination of flip angle of 40 degrees and echo time of 10 ms and the FISP sequence (TR = 40 ms) with combination of flip angle of 40 degrees and echo time of 11 ms were best for depicting cartilage structure and internal detail. There was no significant difference between fat-saturated three-dimensional FLASH (FS-3D-FLASH) and FS-3D-FISP (p = 0.05). These FS-3D sequences were significantly better than sequences without fat saturation (p = 0.05). There was no significant difference between magnetization transfer (MT) 3D-FLASH, MT-3D-FISP and 3D-FISP. All 3D sequences showed significantly (p = 0.05) better results than spin echo or fast spin echo sequences. The T1 weighted SE pulse sequence was significantly (p = 0.005) better than the T2 weighted TSE sequence. Fast T2 weighted spin echo was not suitable for early and accurate detection of cartilage lesions.
    British Journal of Radiology 04/1998; 71(843):291-6. · 1.22 Impact Factor
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    ABSTRACT: The aim of our study was to correlate MRI with histologic findings in normal and degenerative cartilage. Twenty-two human knees derived from patients undergoing amputation were examined with 1.0- and 1. 5-T MR imaging units. Firstly, we optimized two fat-suppressed 3D gradient-echo sequences. In this pilot study two knees were examined with fast imaging with steady precession (FISP) sequences and fast low-angle shot (FLASH, SPGR) sequence by varying the flip angles (40, 60, 90 degrees) and combining each flip angle with different echo time (7, 10 or 11, 20 ms). We chose the sequences with the best visual contrast between the cartilage layers and the best measured contrast-to-noise ratio between cartilage and bone marrow. Therefore, we used a 3D FLASH fat-saturated sequence (TR/TE/flip angle = 50/11 ms/40 degrees) and a 3D FISP fat-saturated sequence (TR/TE/flip angle = 40/10 ms/40 degrees) for cartilage imaging in 22 human knees. The images were obtained at various angles of the patellar cartilage in relation to the main magnetic field (0, 55, 90 degrees). The MR appearances were classified into five categories: normal, intracartilaginous signal changes, diffuse thinning (cartilage thickness < 3 mm), superficial erosions, and cartilage ulcers. After imaging, the knees were examined macroscopically and photographed. In addition, we performed histologic studies using light microscopy with several different stainings, polarization, and dark field microscopy as well as electron microscopy. The structural characteristics with the cartilage lesions were correlated with the MR findings. We identified a hyperintense superficial zone in the MR image which did not correlate to the histologically identifiable superficial zone. The second lamina was hypointense on MRI and correlated to the bulk of the radial zone. The third (or deep) cartilage lamina in the MR image seemed to represent the combination of the lowest portion of the radial zone and the calcified cartilage. The width of the hypointense second zone correlated weakly to the accumulation of proteoglycans in the radial zone. The trilaminar MRI appearance of the cartilage was only visible when the cartilage was thicker than 2 mm. In cartilage degeneration, we found either a diffuse thinning of all layers or circumscribed lesions ("cartilage ulcer") of these cartilage layers in the MR images. Early cartilage degeneration was indicated by a signal loss in the superficial zone, correlating to the histologically proven damage of proteoglycans in the transitional and radial zone along with destruction of the superficial zone. We found a strong effect of cartilage rotation in the main magnetic field, too. A rotation of the cartilage structures caused considerable variation in the signal intensity of the second lamina. Cartilage segments in a 55 degreesangle to the magnetic main field had a homogeneous appearance, not a trilaminar appearance. The signal behavior of hyaline articular cartilage does not reflect the laminar histologic structure. Osteoarthrosis and cartilage degeneration are visible on MR images as intracartilaginous signal changes, superficial erosions, diffuse cartilage thinning, and cartilage ulceration.
    European Radiology 02/1998; 8(7):1123-9. · 4.34 Impact Factor
  • U Tauer, B Volk, B Heimrich
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    ABSTRACT: In the rat central nervous system, the cerebellar cortex has a stereotypical cytoarchitecture and a characteristic connectivity pattern, both mainly formed post-natally. Organotypic cultures of immature cerebellar tissue were used to study the formation of the cerebellar lamination and the differentiation of Purkinje cells in the absence of their extracerebellar afferents. The lamination was retained in the majority of the cerebellar cultures and most Purkinje cells were aligned. Axonal profiles of Purkinje cells, immunolabelled for UCHT1 or anti-calbindin D-28 k, followed pathways similar to those in vivo cerebellum. The dendrites were orientated towards the superficial layer except of those neurons which were ectopically positioned. Unlike in vivo, the dendritic arborization of Golgi-impregnated/gold-toned or immunostained Purkinje cells was reduced and the dendritic spines were often elongated. Somatic spines, a morphological feature of immature Purkinje cells persisted even after 4 weeks in culture. We conclude that the Purkinje cells in organotypic cultures send their axon to the correct target region independent of their local position. In contrast, the dendritic orientation and differentiation is influenced by the cellular environment and by specific synaptic interaction.
    Neuropathology and Applied Neurobiology 09/1996; 22(4):361-9. · 4.84 Impact Factor