Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0533
    Keywords: Key words Paired helical filament ; Neurofibrillary ; tangles ; Scanning electron microscopy ; Alzheimer’s ; disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Neurofibrillary tangles (NFTs) have been ultrastructually studied by various methods, leading to several three-dimensional models of paired helical filaments (PHFs). In this study, we present the scanning electron microscopic findings of NFTs in an autopsy case of Alzheimer’s disease and clarify the three-dimensional structures of NFTs. NFTs were clearly defined in freeze-cracked nerve cells and consisted of two types of filamentous structures, straight and helical filaments. Straight filaments measured from 20 to 25 nm in diameter and had a smooth surface. They were slightly bent but mostly straight with no constrictions. One type of straight filaments ran in a bundle in the same direction, another was intertwined to each other. Most of the helical profiles of filaments usually measured about 28 nm in diameter, with a distance of 100 nm between periodic constrictions. They seemed to consist of a pair of isodiametric filaments of 10 nm in diameter. In addition, two unusual types of helical filaments were occasionally observed. One comprised thick filaments of about 38 nm in diameter, with a distance of 100 nm between constrictions; these helical filaments appeared to consist of two or more strands. The other comprised thin helical filaments of about 20 nm in diameter and regularly constricted at an interval of 50 nm. All types of the helical filaments examined in this case were leotropic. This result supports a protofilament model of PHFs. Scanning electron microscopy using the freeze-cracked and maceration method is a useful and simple method for three-dimensional observation of the filamentous structures in NFTs.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 96 (1998), S. 179-184 
    ISSN: 1432-0533
    Keywords: Key words Paired helical filaments ; Neurofibrillary ; tangles ; Down’s syndrome ; Alzheimer’s disease ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An autopsy case of a 64-year old woman with Down’s syndrome (DS) is reported with a special reference to the ultrastructure of neurofibrillary tangles (NFTs). NFTs and senile plaques were diffusely observed throughout the brain. The most severe changes were seen in the amygdaloid nuclear complex and hippocampus. Immunohistochemistry of the NFTs and senile plaques indicated the features identical to those in Alzheimer’s disease (AD). Ultrastructurally, NFTs were composed of straight filaments and two profiles of paired helical filaments (PHFs). By transmission electron microscopy, straight filaments measured 25–28 nm in diameter. As to the PHFs, one type was 33 nm in maximum diameter and constricted at a 75– to 80-nm interval. The other was 16–18 nm in maximum diameter and constricted at a 35– to 40-nm interval. By scanning electron microscopy, the diameter of the straight filaments measured up to 28–30 nm. Two profiles of PHFs were observed. One type of PHF showed thick filaments about 34 nm in maximum diameter and constrictions at an 80-nm interval. The other was about 17 nm in diameter and constricted at a 40-nm interval. The helical directions of both PHFs were left-handed. The frequency of PHFs with short interval was much higher in DS than AD. Furthermore, the length of the periodicity of this type of PHF was somewhat less than that of AD. Thus, these findings suggest that the neuropathological changes in DS and AD share a common etiopathology, but that some differences in the PHFs between DS and AD may reflect on molecular difference in the proteins or peptides associated with PHF formation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...