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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 77 (1989), S. 258-266 
    ISSN: 1432-0533
    Keywords: Neurofibrillary tangles ; Alzheimer's disease ; Pick bodies ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have studied the immunohistochemical reactivity and ultrastructure of both neurofibrillary tangles (NFTs) occurring with severe neurofibrillary diseases, and Pick bodies (PBs) associated with Pick's disease. The NFTs and PBs did not react immunohistochemically with the anti-nonphosphorylated neurofilament monoclonal antibody irrespective of whether they were pretreated with alkaline phosphatase. In granular neurons of the dentate fascia of Ammon's horn in cases of dementia of the Alzheimer type (DAT), NFTs either resembled PB-like inclusion bodies (Horoupian's inclusion bodies) in form, or had a perinuclear structure. Immunohistochemically and ultrastructurally, the NFTs in the dentate fascia in cases of DAT, including Horoupian's inclusion bodies, were similar to the NFTs in the pyramidal neurons of Ammon's horn, which are found most frequently in association with severe neurofibrillary diseases. Under a light microscope, Horoupian's inclusion bodies and PBs could not be differentiated and appeared to be argyrophilic round cytoplasmic inclusions in granular neurons of the dentate fascia. There were, however, ultrastructural differences. Horoupian's inclusion bodies consisted of bundles made up of straight tubules (STs), each about 15 nm in diameter. These bundles were intermixed with a few paired helical filaments which occurred at intervals of about 80 nm. On the other hand, PBs were composed of randomly distributed 15-nm-wide STs, intermixed with a very few fibrillary structures. These fibrils had a periodicity of about 160 nm, and ranged in width from about 15 nm to 30 nm. Horoupian's inclusion bodies associated with DAT and PBs associated with Pick's disease are different in this neuropathological aspect. The NFTs, including Horoupian's inclusion bodies in the dentate fascia in cases of DAT, are considered to be a manifestation of neurofibrillary degeneration.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0533
    Keywords: Olivopontocerbellar atrophy ; Argyrophilic inclusion ; Pontine nucleus ; Ubiquitin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Patients with olivopontocerebellar atrophy (OPCA) were studied, and cytoplasmic inclusions were observed in some of the remaining neurons of the pontine nuclei, nuclei reticularis tegmenti pontis and arcuate nuclei. The cytoplasmic argyrophilic inclusions were demonstrated by silver impregnation techniques such as Bielschowsky and Bodian staining. With hematoxylin and eosin stain, the inclusions were sharply demarcated and appeared pale. The inclusions were not stained by the following routine histological methods: Klüver-Barrera, phosphotungstic acid hematoxylin, Holzer, periodic acid-Schiff, Mallory azan, alcian blue, nile blue, Masson trichrome, Congo red, thioflavine S, oil red O and Sudan black B stains. Immunohistochemistry with anti-ubiquitin antiserum showed that these inclusions were ubiquitinated. However, the inclusions did not react with any of the following antibodies (Abs) or antisera: anti-phosphorylated neurofilament (NF) Ab, anti-nonphosphorylated NF Abs (160 and 200 kDa), anti-paired helical filament antiserum, anti-tau antiserum, anti-tubulin Abs (alpha and beta), anti-microtubule-associated proteins antiserum, anti-glial fibrillary acidic protein antiserum, anti-vimentin Ab, anti-desmin Ab, anti-cytokeratin Abs (low and high molecular weights), anti-actin antiserum, anti-skeletal myosin antiserum and anti-myelin basic protein Ab. Ultrastructurally, the inclusion bodies noted in OPCA were composed primarily of fibrils having a width ranging from about 24 to 40 nm, which were entirely coated with osmiophilic granular material along their whole length. They were occasionally intermingled with a few filaments about 10 nm in width. Electron microscopical examination on silver-impregnated specimens revealed that each granule-coated fibril had a great affinity for silver particles. In elucidating the pathogenesis of OPCA, it was considered to be an important neuropathological finding that some of the remaining pontine neurons affected by OPCA developed characteristic cytoplasmic argyrophilic inclusions.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0533
    Keywords: Creutzfeldt-Jakob disease ; Ballooned neurons ; Ultrastructure ; αB-Crystallin ; Stress-response proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This report concerns ultrastructural and immunohistochemical studies on ballooned neurons of ten patients with Creutzfeldt-Jakob disease (CJD). While abundant ballooned neurons and severe white matter degeneration was seen in six Japanese cases, only occasional ballooned neurons and no white matter degeneration was observed in four cases from the files of Montefiore Medical Center. Ultrastructurally, the ballooned neurons contained granule-coated fibrils of 25 to 40 nm in width and 10-nm neurofilaments. The immunohistochemical studies revealed that most ballooned neurons expressed αB-crystallin, with deposits of reaction products observed in the cytoplasm. A similar intracellular staining pattern was also seen with the antibody to phosphorylated neurofilament proteins (pNFP). Although the proportion of stained ballooned neurons was less, a positive reaction was also observed with antibodies against ubiquitin, stress-response protein 27 (srp 27) and synptophysin, but not with an antibody to srp 72. Our findings suggest that expression of pNFP and synaptophysin by ballooned neurons may reflect axonal impairment and that the presence of αB-crystallin, srp 27 and ubiquitin may be related to the degenerative processes that neurons undergo in CJD.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0533
    Keywords: Spinal cord neurofibrillary tangles ; Parkinsonism-dementia complex on Guam ; Guamanian amyotrophic lateral sclerosis ; Ultrastructure ; Immunoelectron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The immunohistochemical and ultrastructural characteristics of spinal cord neurofibrillary tangles (NFTs) were examined in Guamanian amyotrophic lateral sclerosis and in parkinisonism-dementia complex on Guam. The spinal cord NFTs reacted with antibodies to tau protein (tau-2), ubiqitin and paired helical filaments (PHFs). Ultrastructurally, the components of the NFTs were seen as randomly arranged fibrils which were often associated with osmiophilic granules; small bundle-like arrangements were also occasionally observed. Individual NFT fibrils appeared as straight fibrils with a diameter of approximately 15 nm and constricted fibrils with a periodicity of approximately 80 nm. Ultrastructural microscopic examination of specimens stained by the modified Bielschowsky method and with the antibodies revealed silver particles and the products of the tau, ubiquitin and PHF immunoreactions on the NFT fibrils. This is the first demonstration of the fine structure of the spinal cord NFTs.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-0649
    Keywords: 07.75 ; 33.00 ; 82.50
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A MultiPhoton-Ionization Time-Of-Flight Mass Spectrometry (MPI/TOFMS) apparatus was developed for real-time measurement of the uranium isotopic ratio in nascent UF5 formed by the 266 nm photolysis of effusive UF6 ( 〈 300 K, ≈ 1.3 × 10−4 Pa). The UF5 was selectively and efficiently multiphoton ionized by 532 nm radiation at appreciably low fluences ( 〈 10 J/cm2). The main ions observed, U+ and U2+, were subsequently analyzed with a TOFMS with mass resolution of 1190 to separate235U n+ and238U n+ completely. The isotopic ratio measurements showed good precision resulting from the excellent agreement which was observed between the isotopic ratios in UF5 products and those in a parent UF6 sample. These results suggested that the MPI/TOFMS method can be applied to the real-time analysis of separation factors in the molecular laser isotope separation of uranium by ionization of UF5 following the infrared photodissociation of UF6.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 28 (1982), S. 341-348 
    ISSN: 1432-0649
    Keywords: 82.50 ; 82.40 ; 42.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Isotope separation of tritium by CO2 laser-induced multiphoton dissociation (MPD) of C2TF5 is reported for the first time. The MPD spectrum obtained for C2TF5 comprised a broad peak at about 940 cm−1 where C2HF5 was nearly transparent. The unimolecular dissociation of C2TF5 was induced with much lower laser fluence than that for CTF3, another working molecule we proposed for laser isotope separation of tritium. The mechanisms and kinetics of the dissociation of C2TF5 and C2HF5 were investigated under various experimental conditions: laser frequency, pulse energy, pulse duration, tritium concentration, sample pressure, buffer gas pressure and irradiation geometry. Single-step separation factors exceeding 500 were achieved with the most efficientP(20) line in 00o–10o0 transition at 944.2 cm−1.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0649
    Keywords: 82.50 ; 82.40 ; 42.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Isotope separation of tritium from deuterium in heavy water was attempted by CO2-laser-induced, highly-selective multiphoton dissociation of C2TF5 present in C2DF5. Single-step T/D separation factors exceeding 3000, 1000, and 500 were attained, respectively, for the first time with CO2 laser 10P(34) 931.0 cm−1 at 10, 20, and 30 Torr pentafluoroethane pressures at −78 °C (i.e., equivalent to 15, 30, and 45 Torr at room temperature).
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 42 (1987), S. 167-172 
    ISSN: 1432-0649
    Keywords: 82.50 ; 82.40 ; 42.60.Kg
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new working molecule 1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl)-propane-2-t (CF3)3CT, is reported for the isotope separation of tritium by TEA CO2-laser-induced multiphoton dissociation (MPD). Selective and efficient dissociation of (CF3)3CT was observed by irradiation at about 980 cm−1 where (CF3)3CH was nearly transparent. The critical fluence for dissociation of (CF3)3CT at 10R(28) 980.9 cm−1 was estimated to be as low as 4.6 J/cm2, which is the lowest of the tritiated halocarbons that we have ever reported. A detailed study was made of the pressure dependence of the dissociation rate constants for (CF3)3CT and (CF3)3CH to clarify the collisional effects in their MPD. The hydrogen isotope exchange between (CF3)3CH and HTO was found to be extremely rapid, which is advantageous in the practical laser separation cycle for tritium removal from water.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-0649
    Keywords: 82.50 ; 33.00
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In infrared multiphoton dissociation of supercooled UF6 irradiated with multifrequency para-H2 Raman laser beams, separation factors and contrast ratios were measured by selective multiphoton ionization of the photoproduct UF5 at 532 nm followed by time-of-flight mass spectrometric analysis. The relationship between separation factor and contrast ratio is discussed theoretically and quantitatively investigated in the experiments. From this relationship, we obtain the irradiation conditions of the laser-beam fluences for attaining a high separation factor and estimate the value of the intrinsic separation factor in multifrequency dissociation of UF6.
    Type of Medium: Electronic Resource
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