QUANTITATIVE ANALYSIS OF MYELINATED AXONS OF CORPUS CALLOSUM IN THE HUMAN BRAIN

2007 ◽  
Vol 117 (6) ◽  
pp. 749-755 ◽  
Author(s):  
MUSTAFA F. SARGON ◽  
H. HAMDİ ÇELİK ◽  
M. DOĞAN AKŞİT ◽  
ERGÜN KARAAĞAOĞLU
Keyword(s):  
Quantitative Analysis ◽  
Corpus Callosum ◽  
Human Brain ◽  
Myelinated Axons

scholarly journals 3D 31 P MRSI of the human brain at 9.4 Tesla: Optimization and quantitative analysis of metabolic images

2021 ◽  
Author(s):  
Loreen Ruhm ◽  
Johanna Dorst ◽  
Nikolai Avdievitch ◽  
Andrew Martin Wright ◽  
Anke Henning
Keyword(s):  
Quantitative Analysis ◽  
Human Brain

scholarly journals A Quantitative Analysis of the Microvascular Sequestration of Malaria Parasites in the Human Brain

1999 ◽  
Vol 155 (2) ◽  
pp. 395-410 ◽  
Author(s):  
Kamolrat Silamut ◽  
Nguyen H. Phu ◽  
Christopher Whitty ◽  
Gareth D.H. Turner ◽  
Karina Louwrier ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Human Brain ◽  
Malaria Parasites

scholarly journals Alterations in Sub-Axonal Architecture Between Normal Aging and Parkinson’s Diseased Human Brains Using Label-Free Cryogenic X-ray Nanotomography

2020 ◽  
Vol 14 ◽  
Author(s):  
Hung Tri Tran ◽  
Esther H. R. Tsai ◽  
Amanda J. Lewis ◽  
Tim Moors ◽  
J. G. J. M. Bol ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Human Brain ◽  
Brain Tissue ◽  
Multispectral Imaging ◽  
Alpha Synuclein ◽  
Label Free ◽  
Myelinated Axons ◽  
X Ray ◽  
X Ray Imaging ◽  
Non Destructive

Gaining insight to pathologically relevant processes in continuous volumes of unstained brain tissue is important for a better understanding of neurological diseases. Many pathological processes in neurodegenerative disorders affect myelinated axons, which are a critical part of the neuronal circuitry. Cryo ptychographic X-ray computed tomography in the multi-keV energy range is an emerging technology providing phase contrast at high sensitivity, allowing label-free and non-destructive three dimensional imaging of large continuous volumes of tissue, currently spanning up to 400,000 μm3. This aspect makes the technique especially attractive for imaging complex biological material, especially neuronal tissues, in combination with downstream optical or electron microscopy techniques. A further advantage is that dehydration, additional contrast staining, and destructive sectioning/milling are not required for imaging. We have developed a pipeline for cryo ptychographic X-ray tomography of relatively large, hydrated and unstained biological tissue volumes beyond what is typical for the X-ray imaging, using human brain tissue and combining the technique with complementary methods. We present four imaged volumes of a Parkinson’s diseased human brain and five volumes from a non-diseased control human brain using cryo ptychographic X-ray tomography. In both cases, we distinguish neuromelanin-containing neurons, lipid and melanic pigment, blood vessels and red blood cells, and nuclei of other brain cells. In the diseased sample, we observed several swellings containing dense granular material resembling clustered vesicles between the myelin sheaths arising from the cytoplasm of the parent oligodendrocyte, rather than the axoplasm. We further investigated the pathological relevance of such swollen axons in adjacent tissue sections by immunofluorescence microscopy for phosphorylated alpha-synuclein combined with multispectral imaging. Since cryo ptychographic X-ray tomography is non-destructive, the large dataset volumes were used to guide further investigation of such swollen axons by correlative electron microscopy and immunogold labeling post X-ray imaging, a possibility demonstrated for the first time. Interestingly, we find that protein antigenicity and ultrastructure of the tissue are preserved after the X-ray measurement. As many pathological processes in neurodegeneration affect myelinated axons, our work sets an unprecedented foundation for studies addressing axonal integrity and disease-related changes in unstained brain tissues.

scholarly journals Non-local means based Rician noise filtering for diffusion tensor and kurtosis imaging in human brain and spinal cord

2020 ◽  
Author(s):  
Zhongping Zhang ◽  
Dhanashree Vernekar ◽  
Wenshu Qian ◽  
Mina Kim
Keyword(s):  
Spinal Cord ◽  
Corpus Callosum ◽  
Human Brain ◽  
Healthy Subjects ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Chi Square ◽  
Lateral Column ◽  
Diffusion Weighted Images ◽  
The Brain

Abstract Background: To investigate the effect of using an Rician nonlocal means (NLM) filter on quantification of diffusion tensor (DT)- and diffusion kurtosis (DK)-derived metrics in various anatomical regions of the human brain and the spinal cord, when combined with a constrained linear least squares (CLLS) approach.Methods: Prospective brain data from 9 healthy subjects and retrospective spinal cord data from 5 healthy subjects from a 3T MRI scanner were included in the study. Prior to tensor estimation, registered diffusion weighted images were denoised by an optimized blockwise NLM filter with CLLS. Mean kurtosis (MK), radial kurtosis (RK), axial kurtosis (AK), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD) and fractional anisotropy (FA), were determined in anatomical structures of the brain and the spinal cord. DTI and DKI metrics, signal-to-noise ratio (SNR) and Chi-square values were quantified in distinct anatomical regions for all subjects, with and without Rician denoising. Results: The averaged SNR significantly increased with Rician denoising by a factor of 2 while the averaged Chi-square values significantly decreased up to 61 % in the brain and up to 43% in the spinal cord after Rician NLM filtering. In the brain, the mean MK varied from 0.70 (putamen) to 1.27 (internal capsule) while AK and RK varied from 0.58 (corpus callosum) to 0.92 (cingulum) and from 0.70 (putamen) to 1.98 (corpus callosum), respectively. In the spinal cord, FA varied from 0.78 in lateral column to 0.81 in dorsal column while MD varied from 0.91 × 10−3 mm2/s (lateral) to 0.93 × 10−3 mm2/s (dorsal). RD varied from 0.34 × 10−3 mm2/s (dorsal) to 0.38 × 10−3 mm2/s (lateral) and AD varied from 1.96 × 10−3 mm2/s (lateral) to 2.11 × 10−3 mm2/s (dorsal).Conclusions: Our results show Rician denoising NLM filter incorporated with CLLS significantly increases SNR and reduces estimation errors of DT- and KT-derived metrics, providing the reliable metrics estimation with adequate SNR levels.

scholarly journals Human brain harbors single nucleotide somatic variations in functionally relevant genes possibly mediated by oxidative stress

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2520 ◽  
Author(s):  
Anchal Sharma ◽  
Asgar Hussain Ansari ◽  
Renu Kumari ◽  
Rajesh Pandey ◽  
Rakhshinda Rehman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Corpus Callosum ◽  
Human Brain ◽  
Frontal Cortex ◽  
Oxidative Stress Marker ◽  
Somatic Variation ◽  
Single Nucleotide ◽  
Normal Human Brain ◽  
Normal Human ◽  
The Brain

Somatic variation in DNA can cause cells to deviate from the preordained genomic path in both disease and healthy conditions. Here, using exome sequencing of paired tissue samples, we show that the normal human brain harbors somatic single base variations measuring up to 0.48% of the total variations. Interestingly, about 64% of these somatic variations in the brain are expected to lead to non-synonymous changes, and as much as 87% of these represent G:C>T:A transversion events. Further, the transversion events in the brain were mostly found in the frontal cortex, whereas the corpus callosum from the same individuals harbors the reference genotype. We found a significantly higher amount of 8-OHdG (oxidative stress marker) in the frontal cortex compared to the corpus callosum of the same subjects (p<0.01), correlating with the higher G:C>T:A transversions in the cortex. We found significant enrichment for axon guidance and related pathways for genes harbouring somatic variations. This could represent either a directed selection of genetic variations in these pathways or increased susceptibility of some loci towards oxidative stress. This study highlights that oxidative stress possibly influence single nucleotide somatic variations in normal human brain.

Analysis of 3D Corpus Callosum Images in the Brains of Autistic Individuals

2016 ◽  
pp. 159-184
Author(s):  
Ahmed Elnakib ◽  
Manuel F. Casanova ◽  
Ahmed Soliman ◽  
Georgy Gimel'farb ◽  
Ayman El-Baz
Keyword(s):  
Autism Spectrum Disorder ◽  
Corpus Callosum ◽  
Human Brain ◽  
Shape Analysis ◽  
Neurodevelopmental Disorder ◽  
Autism Spectrum ◽  
Cerebral Hemispheres ◽  
Higher Cognitive Functions ◽  
The Right ◽  
Abnormal Anatomy

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that is characterized by abnormalities in behavior and higher cognitive functions. The corpus callosum (CC) is the largest fiber bundle that connects the left and the right cerebral hemispheres of the human brain. Several studies have revealed an abnormal anatomy of the CC in the brains of autistic individuals that associates this neurodevelopmental condition with impaired communication between the hemispheres. In this chapter, we develop a framework to analyze the CC of autistic individuals in order to provide a diagnostic tool for autism. The key advantage of this approach is the development of a cylindrical mapping that offers simplified coordinates for comparing the brains of autistic individuals and neurotypicals. Experimental results showed significant differences (at the 95% confidence level) between 17 normal and 17 autistic subjects in four anatomical divisions, i.e. splenium, rostrum, genu, and body of their CCs. Moreover, the initial centerline-based shape analysis of the CC documented a promising supplement to the current techniques for diagnosing autism.

THE AUTOMATED SEGMENTATION TECHNIQUES OF T2-WEIGHTED MRI IMAGES USING K-MEANS CLUSTERING AND OTSU-BASED THRESHOLDING METHOD

2016 ◽  
Vol 78 (6-4) ◽  
Author(s):  
Iza Sazanita Isa ◽  
Siti Noraini Sulaiman ◽  
Muzaimi Mustapha
Keyword(s):  
Quantitative Analysis ◽  
Human Brain ◽  
Intensity Distribution ◽  
Automated Segmentation ◽  
Qualitative And Quantitative Analysis ◽  
Qualitative And Quantitative ◽  
Threshold Levels ◽  
Thresholding Method ◽  
Segmented Images ◽  
Feature Values

The k-means clustering and Otsu-based thresholding of MRI images segmentation are widely used to cluster the lesions in human brain. The main objective of this paper is to employ both algorithms concept to obtain the optimum value of clusters center and threshold levels for a better segmentation process. Both segmentation approaches were used to partition the images into separate classes which are composed of pixels that have similar pre-defined feature values. The evaluation of both segmentation techniques were measured via qualitative and quantitative analysis. From the analysis of the results, it is justified that the proposed approaches are able to efficiently illustrate good segmentation results. The K-means algorithm is also successfully preserved important features of the MRI segmented images as the larger number of clustering reveals bigger grayscale intensity distribution on delineation marks of the MS lesions.

scholarly journals Determination of Vitamin D and Its Metabolites in Human Brain Using an Ultra-Pressure LC–Tandem Mass Spectra Method

2019 ◽  
Vol 3 (7) ◽  
Author(s):  
Xueyan Fu ◽  
Gregory G Dolnikowski ◽  
William B Patterson ◽  
Bess Dawson-Hughes ◽  
Tong Zheng ◽  
...  
Keyword(s):  
Vitamin D ◽  
Corpus Callosum ◽  
Human Brain ◽  
Vitamin D3 ◽  
Temporal Cortex ◽  
National Development ◽  
Brain Regions ◽  
Accurate Information ◽  
Vitamin D Metabolites

ABSTRACTBackgroundLow serum total 25-hydroxyvitamin D3 [25(OH)D3] concentrations have been associated with cognitive impairment. However, it is unclear if serum 25(OH)D3 concentrations are a valid indicator of the concentrations of vitamin D and its metabolites in human brain.ObjectivesThe aim of this study was to develop and validate a method to quantify vitamin D3, 25(OH)D3, and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] in human brain.MethodsThe assay developments were performed using porcine brains. Liquid extraction was used in homogenized samples (∼0.1 g each) prior to analysis by LC-MS/MS with electrospray ionization following derivatization with 4-phenyl-1,2,4-triazoline-3,5-dione. This method was then applied to the determination of vitamin D and its metabolites in a whole human brain obtained from the National Development and Research Institutes.ResultsThe method showed good linearity of vitamin D3, 25(OH)D3, and 1,25(OH)2D3 over the physiological range (R2 = 0.9995, 0.9968, and 0.9970, respectively). The lowest detection limit for vitamin D3, 25(OH)D3, and 1,25(OH)2D3 in porcine brain was 25, 50 and 25 pg/g, respectively. The method was successfully applied to the determination of vitamin D3 and its metabolites in the prefrontal cortex, middle frontal cortex, middle temporal cortex, cerebellum, corpus callosum, medulla, and pons of a human brain. All analyzed human brain regions contained 25(OH)D3, with corpus callosum containing 334 pg/g compared with 158 pg/g in cerebellum. 1,25(OH)2D3 was only detected in prefrontal and middle frontal cortices at a very low level. No vitamin D3 was detected in any examined areas of this single human brain.ConclusionsTo the best of our knowledge, this study is the first report of the measurement of concentrations of vitamin D metabolites in human brain. This validated method can be applied to postmortem studies to obtain accurate information about the presence and role of vitamin D and its metabolites in human brain and neurodegenerative diseases.

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