scholarly journals Longitudinal and Transverse Relaxivity Analysis of Native Ferritin and Magnetoferritin at 7 T MRI

2021 ◽  
Vol 22 (16) ◽  
pp. 8487
Author(s):  
Oliver Strbak ◽  
Lucia Balejcikova ◽  
Martina Kmetova ◽  
Jan Gombos ◽  
Jozef Kovac ◽  
...  
Keyword(s):  
Neurodegenerative Disorders ◽  
Strong Correlation ◽  
Human Tissue ◽  
Model System ◽  
Iron Loading ◽  
Complementary Information ◽  
Non Invasive ◽  
Relaxation Parameters ◽  
Mri Diagnosis ◽  
Mineral Core

Magnetite mineralization in human tissue is associated with various pathological processes, especially neurodegenerative disorders. Ferritin’s mineral core is believed to be a precursor of magnetite mineralization. Magnetoferritin (MF) was prepared with different iron loading factors (LFs) as a model system for pathological ferritin to analyze its MRI relaxivity properties compared to those of native ferritin (NF). The results revealed that MF differs statistically significantly from NF, with the same LF, for all studied relaxation parameters at 7 T: r1, r2, r2*, r2/r1, r2*/r1. Distinguishability of MF from NF may be useful in non-invasive MRI diagnosis of pathological processes associated with iron accumulation and magnetite mineralization (e.g., neurodegenerative disorders, cancer, and diseases of the heart, lung and liver). In addition, it was found that MF samples possess very strong correlation and MF’s relaxivity is linearly dependent on the LF, and the transverse and longitudinal ratios r2/r1 and r2*/r1 possess complementary information. This is useful in eliminating false-positive hypointensive artefacts and diagnosis of the different stages of pathology. These findings could contribute to the exploitation of MRI techniques in the non-invasive diagnosis of iron-related pathological processes in human tissue.

EXPANSION OF HEMATOPOIETIC STEM CELLS IN VITRO AS A MODEL SYSTEM FOR HUMAN TISSUE ENGINEERING

2000 ◽  
Vol 31 (3) ◽  
pp. 499-509 ◽  
Author(s):  
Joel S. Greenberger ◽  
Julie P. Goff ◽  
Jason Bush ◽  
Alfred Bahnson ◽  
Douglas Koebler ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Human Tissue ◽  
Model System ◽  
Hematopoietic Stem

scholarly journals Case Report: Synucleinopathy Associated With Phalaris Neurotoxicity in Sheep

2021 ◽  
Vol 8 ◽  
Author(s):  
Mourad Tayebi ◽  
Pedro Pinczowski ◽  
Umma Habiba ◽  
Rizwan Khan ◽  
Monique A. David ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Neurodegenerative Disorders ◽  
Lewy Bodies ◽  
Model System ◽  
Neuronal Function ◽  
Immunofluorescence Analysis ◽  
Common Endpoint ◽  
Clear Link ◽  
Plant Poisoning ◽  
Pasture Plants

Chronic intoxication with tryptamine-alkaloid-rich Phalaris species (spp.) pasture plants is known colloquially as Phalaris staggers syndrome, a widely occurring neurological disorder of sheep, cattle, horses, and kangaroos. Of comparative interest, structurally analogous tryptamine-alkaloids cause experimental parkinsonism in primates. This study aimed to investigate the neuropathological changes associated with spontaneous cases of Phalaris staggers in sheep with respect to those encountered in human synucleinopathy. In sheep affected with Phalaris staggers, histological, immunohistochemical, and immunofluorescence analysis revealed significant accumulation of neuromelanin and aggregated α-synuclein in the perikaryon of neurons in the cerebral cortex, thalamus, brainstem, and spinal cord. Neuronal intracytoplasmic Lewy bodies inclusions were not observed in these cases of ovine Phalaris staggers. These important findings established a clear link between synucleinopathy and the neurologic form of Phalaris plant poisoning in sheep, demonstrated in six of six affected sheep. Synucleinopathy is a feature of a number of progressive and fatal neurodegenerative disorders of man and may be a common endpoint of such disorders, which in a variety of ways perturb neuronal function. However, whether primary to the degenerative process or a consequence of it awaits clarification in an appropriate model system.

scholarly journals Quantification of Iron Release from Native Ferritin and Magnetoferritin Induced by Vitamins B2 and C

2020 ◽  
Vol 21 (17) ◽  
pp. 6332
Author(s):  
Oliver Strbak ◽  
Lucia Balejcikova ◽  
Martina Kmetova ◽  
Jan Gombos ◽  
Alzbeta Trancikova ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Alternative Hypothesis ◽  
Model System ◽  
Oxide Nanoparticles ◽  
Iron Release ◽  
Ferrous Ions ◽  
Significant Difference ◽  
Mineral Core ◽  
Biogenic Iron ◽  
Over Time

Various pathological processes in humans are associated with biogenic iron accumulation and the mineralization of iron oxide nanoparticles, especially magnetite. Ferritin has been proposed as a precursor to pathological magnetite mineralization. This study quantifies spectroscopically the release of ferrous ions from native ferritin and magnetoferritin as a model system for pathological ferritin in the presence of potent natural reducing agents (vitamins C and B2) over time. Ferrous cations are required for the transformation of ferrihydrite (physiological) into a magnetite (pathological) mineral core and are considered toxic at elevated levels. The study shows a significant difference in the reduction and iron release from native ferritin compared to magnetoferritin for both vitamins. The amount of reduced iron formed from a magnetoferritin mineral core is two to five times higher than from native ferritin. Surprisingly, increasing the concentration of the reducing agent affects only iron release from native ferritin. Magnetoferritin cores with different loading factors seem to be insensitive to different concentrations of vitamins. An alternative hypothesis of human tissue magnetite mineralization and the process of iron-induced pathology is proposed. The results could contribute to evidence of the molecular mechanisms of various iron-related pathologies, including neurodegeneration.

A Model for Non-Invasive Estimation of in Vivo Dialyzer Performances and Patient's Conductivity during Hemodialysis

1993 ◽  
Vol 16 (8) ◽  
pp. 585-591 ◽  
Author(s):  
T. Petitclerc ◽  
N. Goux ◽  
A.L. Reynier ◽  
B. Béné
Keyword(s):  
Strong Correlation ◽  
New Method ◽  
Conductivity Measurements ◽  
Urea Clearance ◽  
Non Invasive ◽  
Model Based ◽  
On Line ◽  
Conventional Methods

On-line monitoring of hemodialysis sessions requires a non-invasive estimation of the parameters concerning the patient's status and the dialyzer performances. We describe here a model based on a new method for non-invasive dialysance and patient conductivity measurements. In this technique the same probe measures alternately the conductivity at the dialysate inlet and outlet for two different dialysate conductivity values. From these data, an appropriate model allows to determine the patient's conductivity as well as the effective dialysance of ionised solutes, that is to say the dialysance corrected for recirculation. A strong correlation is evidenced between the effective dialysance measured by this method and the urea clearance measured by conventional methods (r=0.98 for in vitro solutions; r=0.82 in in vivo situations).

Expansion Of Hematopoietic Stem Cells In Vitro As A Model System For Human Tissue Engineering

1999 ◽  
Vol 26 (4) ◽  
pp. 569-578
Author(s):  
Joel S. Greenberger ◽  
Julie P. Goff ◽  
Jason Bush ◽  
Alfred Bahnson ◽  
Douglas Koebler ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Human Tissue ◽  
Model System ◽  
Hematopoietic Stem

scholarly journals SWS/NTE-dependent neuropathy is the model system to study neurodegeneration

2020 ◽  
Vol 26 ◽  
pp. 67-71
Author(s):  
N. P. Matiytsiv
Keyword(s):  
Life Expectancy ◽  
Life Span ◽  
Glial Cells ◽  
Neurodegenerative Disorders ◽  
Organophosphorus Compounds ◽  
Transmembrane Protein ◽  
Therapeutic Agents ◽  
Model System ◽  
Neuropathy Target Esterase ◽  
Swiss Cheese

Today there is many described neurodegenerative D. melanogaster mutants, which characterized by development of degenerative changes in brain. One of them are a swiss cheese (sws) gene mutants. Mutations in this gene causes apoptosis of neurons and hyperwrapping of their somas by the glial cells, reducing of life expectancy and decrease of locomotion. The sws gene is the ortholog of mammal’s neuropathy target esterase (NTE / PNPLA6). NTE is s neuronal, transmembrane protein, that possesses serinesterase activity, and can be the target for neurotoxic organophosphorus compounds activity. Mutations in PNPLA6 gene cause number hereditary neurodegenerative disorders, which nowadays are incurable. The search for therapeutic agents require use of model objects because researches on humans have both methodical and ethical limitations. During two last decades D. melanogaster has proven itself as a good model for study of neurodegenerative diseases. In this review, we described general characteristics of D. melanogaster gene sws, consequences of its mutations and provided evidences of high conservatism of gene product. Keywords: gene swiss cheese, neuropathy target esterase, neurodegeneration, brain, life span.

scholarly journals Integration of ground-penetrating radar, ultrasonic tests and infrared thermography for the analysis of a precious medieval rose window

2010 ◽  
Vol 24 ◽  
pp. 69-82 ◽  
Author(s):  
L. Nuzzo ◽  
A. Calia ◽  
D. Liberatore ◽  
N. Masini ◽  
E. Rizzo
Keyword(s):  
Infrared Thermography ◽  
Ground Penetrating Radar ◽  
Integrated Approach ◽  
13Th Century ◽  
Complementary Information ◽  
Multi Scale ◽  
Architectural Elements ◽  
Non Invasive ◽  
Ground Penetrating ◽  
The Rose

Abstract. The integration of high-resolution, non-invasive geophysical techniques (such as ground-penetrating radar or GPR) with emerging sensing techniques (acoustics, thermography) can complement limited destructive tests to provide a suitable methodology for a multi-scale assessment of the state of preservation, material and construction components of monuments. This paper presents the results of the application of GPR, infrared thermography (IRT) and ultrasonic tests to the 13th century rose window of Troia Cathedral (Apulia, Italy), affected by widespread decay and instability problems caused by the 1731 earthquake and reactivated by recent seismic activity. This integrated approach provided a wide amount of complementary information at different scales, ranging from the sub-centimetre size of the metallic joints between the various architectural elements, narrow fractures and thin mortar fillings, up to the sub-metre scale of the internal masonry structure of the circular ashlar curb linking the rose window to the façade, which was essential to understand the original building technique and to design an effective restoration strategy.

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