Unloaded Organ Culturing Has a Detrimental Effect On the Axial Mechanical Properties of the Intervertebral Disc

2021 ◽  
Author(s):  
Derek Zwambag ◽  
Brigitte Laird ◽  
Stephanie DeWitte-Orr ◽  
Diane Gregory
Keyword(s):  
Mechanical Properties ◽  
Entire Range ◽  
Culture Media ◽  
Axial Loading ◽  
Intervertebral Discs ◽  
Neutral Zone ◽  
Mechanical Signals ◽  
Standard Culture ◽  
Rat Tail Model ◽  
Rat Tail

Abstract Healthy function of intervertebral discs (IVDs) depends on their tissue mechanical properties. Native cells embedded within IVD tissues are responsible for building, maintaining, and repairing IVD structures in response to genetic, biochemical, and mechanical signals. Organ culturing provides a method for investigating how cells respond to these stimuli in their natural architectural environment. The purpose of this study was to determine how organ culturing affects the mechanical characteristics of functional spine units (FSUs) across the entire range of axial loading, including the neutral zone, using a rat tail model. Rat tail FSUs were organ cultured at 37°C in an unloaded state in standard culture media for either 1-Day (n=8) or 6-Days (n=12). Non-cultured FSUs (n=12) were included as fresh control specimens. Axial mechanical properties were tested by applying cyclical compression and tension. A novel, mathematical approach was developed to fully characterize the relationship between load, stiffness, and deformation through the entire range of loading. Culturing FSUs for 1-Day did not affect any of the axial mechanical outcome measures compared to non-cultured IVDs; however, culturing for 6-days increased the size of neutral zone by 112% and decreased the stiffness in neutral zone, compressive, and tensile regions by 53%, 19%, and 15% respectively, compared to non-cultured FSUs. These results highlight the importance of considering how the mechanical integrity of IVD tissues may affect the transmission of mechanical signals to cells in unloaded organ culturing experiments.

scholarly journals Effects of Panax ginseng-containing herbal plasters on compressed intervertebral discs in an in vivo rat tail model

2013 ◽  
Vol 8 (1) ◽  
pp. 4 ◽  
Author(s):  
Daniel H K Chow ◽  
Alon Lai ◽  
Fuk-Hay Tang ◽  
Mason C P Leung
Keyword(s):  
Panax Ginseng ◽  
Intervertebral Discs ◽  
Rat Tail Model ◽  
Rat Tail

scholarly journals Effects of compressive loading on biomechanical properties of disc and peripheral tissue in a rat tail model

2009 ◽  
Vol 18 (11) ◽  
pp. 1595-1603 ◽  
Author(s):  
Tomokazu Nakamura ◽  
Takaro Iribe ◽  
Yoshinori Asou ◽  
Hiroo Miyairi ◽  
Kozo Ikegami ◽  
...  
Keyword(s):  
Compressive Loading ◽  
Biomechanical Properties ◽  
Peripheral Tissue ◽  
Rat Tail Model ◽  
Rat Tail

Study on Multi-Axial Mechanical Properties of a Polyurethane Foam and Experimental Verification

2011 ◽  
Vol 311-313 ◽  
pp. 301-308
Author(s):  
Shou Hong Han ◽  
Zhen Hua Lu ◽  
Yong Jin Liu
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Polyurethane Foam ◽  
Axial Compression ◽  
Axial Loading ◽  
Hydrostatic Compression ◽  
Model Parameters ◽  
Loading Conditions ◽  
Three Point Bending ◽  
Pu Foam

In order to investigate the multi-axial mechanical properties of a kind of PU (polyurethane) foam, some experiments in different loading conditions including uni-axial tension, uni-axial compression, hydrostatic compression and three-point bending were conducted. It is shown that the hydrostatic component influences yield behavior of PU foam, the yield strength and degree of strain hardening in hydrostatic compression exceed those for uni-axial compression. In terms of the differential hardening constitutive model, the evolution of PU foam yield surface and plastic hardening laws were fitted from experimental data. A finite element method was applied to analyze the quasi-static responses of the PU foam sandwich beam subjected to three-point bending, and good agreement was observed between experimental load-displacement responses and computational predictions, which validated the multi-axial loading methods and stress-strain constitutive model parameters. Moreover, effects of two foam models applied to uni-axial loading and multi-axial loading conditions were analyzed and compared with three-point bending tests and simulations. It is found that the multi-axial constitutive model can bring more accurate prediction whose parameters are obtained from the tests above mentioned.

Croissance et fructification de Ceratocystis spp. avec attention particulière à C. piceae et C. fimbriata, en fonction du substrat

1982 ◽  
Vol 60 (4) ◽  
pp. 358-363
Author(s):  
A. Thuillier ◽  
P. Neumann
Keyword(s):  
Nutrient Solution ◽  
Culture Media ◽  
Basal Medium ◽  
Malt Agar ◽  
Fruiting Bodies ◽  
Ceratocystis Fimbriata ◽  
Good Production ◽  
Wood Extracts ◽  
Standard Culture ◽  
Better Than

Ceratocystis coerulescens, C. fimbriata, C. ips, and C. minor were tested for production of sexual fruiting bodies, and C. penicillata and C. piceae for asexual fruiting bodies. Ceratocystis fimbriata produced perithecia easily on standard culture media, but there were marked differences between the two strains tested (503, 560). Strain 503 had a good production of fruiting bodies on malt agar (M) and a basal nutrient solution (N). Strain 560 fared better than 503 on Leonian agar (L), but did not fructify on M and N. Supplementing media with various wood extracts produced better results. M + maple sapwood extracts and L + poplar sapwood extracts gave the best results with strain 503, and L + pine sapwood extracts was the best with strain 560.Production of coremia was also influenced by the basal medium and the kind of extracts added as supplements. Fir and maple extracts stimulated the production of fruiting bodies, whereas pine and poplar extracts had no or very little stimulating effects. In every other species tested, the production of fruiting bodies was none or very irregular. [Journal translation]

scholarly journals The effect of Malaysian stingless bee, Trigona spp. honey in promoting proliferation of the undifferentiated stem cell

2019 ◽  
pp. 10-19 ◽  
Author(s):  
Mohd Amin Marwan Mohamad ◽  
Muhammad Alif Mazlan ◽  
Muhammad Ibrahim ◽  
Afzan Mat Yusof ◽  
Shamsul Azlin Ahmad Shamsuddin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Culture Media ◽  
Proliferative Effect ◽  
Natural Medicine ◽  
Ability To Regenerate ◽  
Potential Applications ◽  
Standard Culture ◽  
The Stability ◽  
Dose Dependent ◽  
Standard Culture Medium

Stem cells provide various potential applications in regenerative medicine through its ability of self-renewal and differentiation. Among the various stem cells, dental pulp stem cells (DPSCs) have shown encouraging results in their ability to regenerate. Honey has been used in traditional culture as a natural medicine in supporting wound healing. Yet, very few studies on honey were conducted for its potential as a proliferative agent for stem cells. The aim of this study is to evaluate the stability of two Trigona spp. honeys (1 and 2) added in culture media and its proliferative effect on DPSCs. Both honeys were diluted with standard culture medium through dilution process to prepare the concentrations of 0.01%, 0.04%, 0.10% and 0.25%. DPSCs were treated with the diluted honeys for 24 hours. The proliferative activity was determined through the images taken using an inverted microscope for every six hours. In addition, the MTT assay was conducted to determine the cell viability of DPSCs when treated with both honey 1 and 2 at various concentrations. The results showed a stable culture media added with honey for three days and a dose-dependent proliferative effect of both Trigona spp. honey samples on DPSCs. Optimum proliferative effects were observed at 24 hours for both Trigona spp. honey 1 and 2 on DPSCs. The optimum concentration of Trigona spp. honey 1 was from 0.04% to 0.10% and Trigona spp. honey 2 was below 0.01%. It is concluded that Trigona spp. honey has a promising proliferative effect on DPSCs.

scholarly journals Application of Flow Cytometry to Segregated Kinetic Modeling Based on the Physiological States of Microorganisms

2007 ◽  
Vol 73 (12) ◽  
pp. 3993-4000 ◽  
Author(s):  
Covadonga Quir�s ◽  
M�nica Herrero ◽  
Luis A. Garc�a ◽  
Mario D�az
Keyword(s):  
Flow Cytometry ◽  
Culture Media ◽  
Glucose Consumption ◽  
Viable Cell ◽  
Counting Method ◽  
Batch Cultures ◽  
Viable Cells ◽  
The Status ◽  
Standard Culture

ABSTRACT Flow cytometry (FC) has been introduced to characterize and to assess the physiological states of microorganisms in conjunction with the classical plate-counting method. To show the applicability of the technique, in particular for the development of kinetic models, pure culture fermentation experiments were followed over time, using both prokaryotic (Lactobacillus hilgardii) and eukaryotic (Saccharomyces cerevisiae) microorganisms growing in standard culture media (MRS and YPD). The differences observed between the active and viable cells determined by FC and CFU, respectively, allowed us to determine that a large number of cells were in a viable but nonculturable (VBNC) state, which resulted in a subpopulation much larger than the damaged-cell (double-stained) subpopulation. Finally, the determination of the evolution of viable, the VBNC, and the dead cells allowed us to develop a segregated kinetic model to describe the yeast and the bacteria population dynamics and glucose consumption in batch cultures. This model, more complete than that which is traditionally used, based only on viable cell measurements, describes better the behavior and the functionality of the cultures, giving a deeper knowledge in real time about the status and the course of the bioprocesses.

Experimental Study on Mechanical Properties of Larch Glulam Columns under Axial Compression

2016 ◽  
Vol 847 ◽  
pp. 38-45
Author(s):  
Xian Yan Zhou ◽  
Dan Zeng ◽  
Zhi Feng Wang
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Bearing Capacity ◽  
Axial Strain ◽  
Slenderness Ratio ◽  
Axial Loading ◽  
Ultimate Bearing Capacity ◽  
Reduction Factor ◽  
Peak Strain ◽  
Short Columns

At present, the relevant researches of Glulam columns in China are mainly restricted to short columns. In order to study the mechanical properties of long columns under axial loading, an experimental study on five different slenderness ratios of Larch Glulam columns was carried out. With slenderness ratio changing, the variations of experimental data such as axial strain, lateral deflection at mid-height, ultimate bearing capacity, and peak strain were comparatively analyzed. The failure pattern and failure mechanism of long columns were discussed. The results indicate that the ultimate bearing capacity of Larch Glulam columns gradually decreases as the slenderness radio increases and the failure mode is gradually converted from strength failure to instability failure. The ultimate load reduction factor is obtained by regression analysis based on the experiment results of Larch Glulam short columns. The basis for design and application of Larch Glulam columns are provided.

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