scholarly journals Age-dependent microstructural changes of the intervertebral disc: a validation of proteoglycan-sensitive spectral CT

2021 ◽  
Author(s):  
Julian Pohlan ◽  
Carsten Stelbrink ◽  
Matthias Pumberger ◽  
Dominik Deppe ◽  
Friederike Schömig ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Intervertebral Disc ◽  
Chondroitin Sulfate ◽  
Ex Vivo ◽  
Microstructural Analysis ◽  
Inverse Correlation ◽  
Anulus Fibrosus ◽  
Sulfate Content ◽  
Age Related ◽  
Age Related Changes

Abstract Objective To analyze the two major components of the intervertebral disc (IVD) in an ex vivo phantom, as well as age-related changes in patients. Methods Collagen and chondroitin sulfate were imaged at different concentrations in agar solution. Age-related changes in disc density were retrospectively analyzed in normal-appearing discs in dual-energy computed tomography (DECT) images from a patient cohort with various spinal pathologies (n = 136). All computed tomography (CT) scans were acquired using single-source DECT at 80 and 135 kVp with automatic exposure calculation. In 136 patients, the attenuation of normal-appearing discs on collagen/chondroitin maps (cMaps) correlated with the patients’ age with Pearson’s r using standardized regions of interest in the anterior anulus fibrosus (AAF) and nucleus pulposus (NP). Results DECT collagen mapping revealed concentration-dependent Hounsfield units (HU) of IVD components. For collagen, we found Pearson’s r = 0.9610 (95% CI 0.6789–0.9959), p = 0.0023 at 120 kVe, and r = 0.8824 (95% CI 0.2495–0.9871), p = 0.0199 in cMap. For chondroitin sulfate, Pearson’s r was 0.9583 (95% CI 0.6603–0.9956), p = 0.0026 at 120 kVp, and r = 0.9646 (95% CI 0.7044–0.9963), p = 0.0019 in cMap. Analysis of normal-appearing IVDs revealed an inverse correlation of density with age in the AAF: Pearson’s r = − 0.2294 at 135 kVp (95% CI − 0.4012 to − 0.04203; p=0.0141) and r = − 0.09341 in cMap (95% CI − 0.2777 to 0.09754; p = 0.0003). In the NP, age and density did not correlate significantly at 135 kVp (p = 0.9228) and in cMap (p = 0.3229). Conclusions DECT-based collagen mapping allows microstructural analysis of the two main intervertebral disc components—collagen and chondroitin sulfate. IVD density declines with age, presumably due to a reduction in collagen and chondroitin sulfate content. Age-related alterations of disc microstructure appear most pronounced in the AAF. Key Points • DECT-based collagen mapping allows precise analysis of the two main intervertebral disc components—collagen and chondroitin sulfate. • Intervertebral disc (IVD) density declines with age, presumably due to a reduction in collagen and chondroitin sulfate content. • Age-related alterations of disc microstructure are most pronounced in the anterior anulus fibrosus (AAF).

scholarly journals Age-Related Changes in the Extracellular Matrix of Nucleus Pulposus and Anulus Fibrosus of Human Intervertebral Disc

Spine ◽  
2009 ◽  
Vol 34 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Kern Singh ◽  
Koichi Masuda ◽  
Eugene J-M. A. Thonar ◽  
Howard S. An ◽  
Gabriella Cs-Szabo
Keyword(s):  
Extracellular Matrix ◽  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Anulus Fibrosus ◽  
Age Related ◽  
Age Related Changes

scholarly journals Ex vivo cultures of microglia from young and aged rodent brain reveal age-related changes in microglial function

2012 ◽  
Vol 33 (1) ◽  
pp. 195.e1-195.e12 ◽  
Author(s):  
eMalick G. Njie ◽  
Ellen Boelen ◽  
Frank R. Stassen ◽  
Harry W.M. Steinbusch ◽  
David R. Borchelt ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Rodent Brain ◽  
Age Related ◽  
Age Related Changes

Analysis of Age-related Changes in the Lower Lid and Soft Tissue Using Computed Tomography

2010 ◽  
Vol 51 (11) ◽  
pp. 1427 ◽  
Author(s):  
Won Yeol Ryu ◽  
Byung Uk Ko ◽  
Woo Jin Jeung ◽  
Hee Bae Ahn
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
Age Related ◽  
Age Related Changes

Visualizing patterns of intervertebral disc damage with dual-energy computed tomography: assessment of diagnostic accuracy in an ex vivo spine biophantom

2021 ◽  
pp. 028418512110258
Author(s):  
Julian Pohlan ◽  
Carsten Stelbrink ◽  
Niklas Tuttle ◽  
Felix Kubicka ◽  
Ho Jung Kwon ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Intervertebral Disc ◽  
Diagnostic Accuracy ◽  
Ex Vivo ◽  
Dual Energy ◽  
Detection Accuracy ◽  
Single Source ◽  
Ct Scanner ◽  
Dual Energy Computed Tomography ◽  
Diagnostic Potential

Background Previously, dual-energy computed tomography (DECT) has been established for imaging spinal fractures as an alternative modality to magnetic resonance imaging (MRI). Purpose To analyze the diagnostic accuracy of DECT in visualizing intervertebral disc (IVD) damage. Material and Methods The lumbar spine of a Great Dane dog was used as an ex vivo biophantom. DECT was performed as sequential volume technique on a single-source CT scanner. IVDs were imaged before and after an injection of sodium chloride solution and after anterior discectomy in single-source sequential volume DECT technique using 80 and 135 kVp. Chondroitin/Collagen maps (cMaps) were reconstructed at 1 mm and compared with standard CT. Standardized regions of interest (ROI) were placed in the anterior anulus fibrosus, nucleus pulposus, and other sites. Three blinded readers classified all images as intact disc, nucleus lesion, or anulus lesion. Additionally, clinical examples from patients with IVD lesions were retrospectively identified from the radiological database. Results Interrater reliability was almost perfect with a Fleiss kappa of 0.833 (95% confidence interval [CI] 0.83–0.835) for DECT, compared with 0.780 (95% CI 0.778–0.782) for standard CT. For overall detection accuracy of IVD, DECT achieved 91.0% sensitivity (95% CI 83.6–95.8) and 92.0% specificity (95% CI 80.8–97.8). Standard CT showed 91.0% sensitivity (95% CI 83.6–95.8) and 78.0% specificity (95% CI 64.0–88.5). Conclusion DECT reliably identified IVD damage in an ex vivo biophantom. Clinical examples of patients with different lesions illustrate the accurate depiction of IVD microstructure. These data emphasize the diagnostic potential of DECT cMaps.

scholarly journals Aging of human hematopoietic stem cells is linked to changes in Cdc42 activity

Haematologica ◽  
2021 ◽  
Author(s):  
Amanda Amoah ◽  
Anja Keller ◽  
Ramiz Emini ◽  
Markus Hoenicka ◽  
Andreas Liebold ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Ex Vivo ◽  
The Elderly ◽  
Hematopoietic Stem ◽  
Age Related ◽  
Elevated Activity ◽  
Human Hscs ◽  
Age Related Changes

In this study, we characterize age-related phenotypes of human hematopoietic stem cells (HSCs). We report increased frequencies of HSC, HPC and lineage negative cells in the elderly but a decreased frequency of multi-lymphoid progenitors. Aged human HSCs further exhibited a delay in initiating division ex vivo though without changes in their division kinetics. The activity of the small RhoGTPase Cdc42 was elevated in aged human hematopoietic cells and we identified a positive correlation between Cdc42 activity and the frequency of HSCs upon aging. The frequency of human HSCs polar for polarity proteins was, similar to the mouse, decreased upon aging, while inhibition of Cdc42 activity via the specific pharmacological inhibitor of Cdc42 activity, CASIN, resulted in re-polarisation of aged human HSCs with respect to Cdc42. Elevated activity of Cdc42 in aged HSCs thus contributed to age-related changes in HSCs. Xeno-transplants, using NBSGW mice as recipients, showed elevated chimerism in recipients of aged compared to young HSCs. Aged HSCs treated with CASIN ex vivo displayed an engraftment profile similar to recipients of young HSCs. Taken together, our work reveals strong evidence for a role of elevated Cdc42 activity in driving aging of human HSCs, and similar to mice, this presents a likely possibility for attenuation of aging in human HSCs.

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