CALCULATING MYELIN SHEATH THICKNESS WITH WATERSHED ALGORITHM FOR BIOLOGICAL ANALYSIS

2016 ◽  
Vol 78 (5-6) ◽  
Author(s):  
Kenneth Huang ◽  
Yunxia Ji ◽  
Steed Huang ◽  
Qi Chen

In this paper, the brief reviews of the significance of the myelin thickness to various root courses of the diseases for a human being, and the similarities between the human and the lab mouse being researched extensively so far are presented. Once we establish the necessity for a biological statistical analysis of the myelin thickness with regard to the particular category of the brain cell, we can then develop a mixed algorithm based on the watershed principle and the binaryzation principle that can be used to automatically process the scanning electron microscope pictures in batches. The initial analysis does indicate that the mixed method improved efficiency of data processing while not overlooking some important medical diagnostic factors.  

Author(s):  
J. D. Hutchison

When the transmission electron microscope was commercially introduced a few years ago, it was heralded as one of the most significant aids to medical research of the century. It continues to occupy that niche; however, the scanning electron microscope is gaining rapidly in relative importance as it fills the gap between conventional optical microscopy and transmission electron microscopy.IBM Boulder is conducting three major programs in cooperation with the Colorado School of Medicine. These are the study of the mechanism of failure of the prosthetic heart valve, the study of the ultrastructure of lung tissue, and the definition of the function of the cilia of the ventricular ependyma of the brain.


2019 ◽  
Author(s):  
Huynh TH Nguyen ◽  
Rhiannon J Wood ◽  
Alexa R Prawdiuk ◽  
Sebastian GB Furness ◽  
Junhua Xiao ◽  
...  

AbstractThe neurotrophin, brain-derived neurotrophic factor (BDNF) promotes central nervous system (CNS) myelination during development and after injury. This is achieved via activation of oligodendrocyte-expressed tropomyosin-related kinase (Trk) B receptors. However, while administration of BDNF has shown beneficial effects, BDNF itself has a poor pharmacokinetic profile. Here, we compare two TrkB-targeted BDNF-mimetics, the structural-mimetic, tricyclic dimeric peptide-6 (TDP6) and the non-peptide small molecule TrkB agonist LM22A-4 in the cuprizone model of central demyelination in female mice. Both mimetics promoted remyelination, increasing myelin sheath thickness and oligodendrocyte densities after one-week recovery. Importantly, LM22A-4 exerts these effects in an oligodendroglial TrkB-dependent manner. However, analysis of TrkB signaling by LM22A-4 suggests rather than direct activation of TrkB, LM22A-4 exerts its effects via indirect transactivation of Trk receptors. Overall, these studies support the therapeutic strategy to selectively targeting TrkB activation to promote remyelination in the brain.


Author(s):  
J. B. Pawley

Stereo images add much to an accurate interpretation of surface images produced by the scanning electron microscope (SEM). Although the secondary electron (SE) signal contains considerable information about the micro-topography of the specimen, various non-topographic information may also be present. Because the process of binocular stereopsis by which we "see" in stereo depends chiefly on pattern recognition rather than on brightness, it discriminates against brightness artifacts and conveys a more accurate and if necessary, fully quantitative, impression of the actual micro-topography of the specimen surface.Stereo-pairs are normally produced by photographing a first view, tilting the specimen about 8 deg and then translating it so that the prominent features are again found in about the same position of the screen and finally recording the second image. The two images are viewed using one of a variety of devices designed to present each image only to the appropriate eye so that the two images can be fused and processed by the brain to produce a 3-D image.


2018 ◽  
Author(s):  
Jessica L Fletcher ◽  
Rhiannon J Wood ◽  
Jacqueline Nguyen ◽  
Eleanor ML Norman ◽  
Christine MK Jun ◽  
...  

AbstractMethods to promote myelin regeneration in response to central myelin loss are essential to prevent the progression of clinical disability in demyelinating diseases. The neurotrophin brain-derived neurotrophic factor (BDNF) is known to promote myelination during development via oligodendrocyte expressed TrkB receptors. Here, we use a structural mimetic of BDNF to promote myelin regeneration in a preclinical mouse model of central demyelination. We show that selective targeting of TrkB with the BDNF-mimetic enhances remyelination, increasing oligodendrocyte differentiation, the frequency of myelinated axons, and myelin sheath thickness after a demyelinating insult. Treatment with exogenous BDNF exerted an attenuated effect, increasing myelin sheath thickness only. Further, following conditional deletion of TrkB from pre-myelinating oligodendrocytes, we show the effects of the BDNF-mimetic on oligodendrocyte differentiation and remyelination are lost, indicating these are dependent on oligodendrocyte expression of TrkB. Overall, these studies demonstrate that targeting oligodendrocyte TrkB promotes in vivo remyelination in the brain.


Author(s):  
D. E. Fornwalt ◽  
A. R. Geary ◽  
B. H. Kear

A systematic study has been made of the effects of various heat treatments on the microstructures of several experimental high volume fraction γ’ precipitation hardened nickel-base alloys, after doping with ∼2 w/o Hf so as to improve the stress rupture life and ductility. The most significant microstructural chan§e brought about by prolonged aging at temperatures in the range 1600°-1900°F was the decoration of grain boundaries with precipitate particles.Precipitation along the grain boundaries was first detected by optical microscopy, but it was necessary to use the scanning electron microscope to reveal the details of the precipitate morphology. Figure 1(a) shows the grain boundary precipitates in relief, after partial dissolution of the surrounding γ + γ’ matrix.


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.


Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.


Author(s):  
T. Kanetaka ◽  
M. Cho ◽  
S. Kawamura ◽  
T. Sado ◽  
K. Hara

The authors have investigated the dissolution process of human cholesterol gallstones using a scanning electron microscope(SEM). This study was carried out by comparing control gallstones incubated in beagle bile with gallstones obtained from patients who were treated with chenodeoxycholic acid(CDCA).The cholesterol gallstones for this study were obtained from 14 patients. Three control patients were treated without CDCA and eleven patients were treated with CDCA 300-600 mg/day for periods ranging from four to twenty five months. It was confirmed through chemical analysis that these gallstones contained more than 80% cholesterol in both the outer surface and the core.The specimen were obtained from the outer surface and the core of the gallstones. Each specimen was attached to alminum sheet and coated with carbon to 100Å thickness. The SEM observation was made by Hitachi S-550 with 20 kV acceleration voltage and with 60-20, 000X magnification.


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