scholarly journals In Vitro Model for Lumbar Disc Herniation to Investigate Regenerative Tissue Repair Approaches

2021 ◽  
Vol 11 (6) ◽  
pp. 2847
Author(s):  
Laura Zengerle ◽  
Elisabeth Debout ◽  
Bruno Kluger ◽  
Lena Zöllner ◽  
Hans-Joachim Wilke
Keyword(s):  
Lumbar Disc Herniation ◽  
Disc Herniation ◽  
Tissue Repair ◽  
Lumbar Disc ◽  
Biomechanical Properties ◽  
Test Method ◽  
In Vitro Test ◽  
Worst Case ◽  
Vitro Test

Featured Application: Development of a lumbar disc herniation model with which regenerative tissue repair approaches can be investigated under physiological loading conditions and worst-case scenarios out of patients’ daily-life.Abstract: Lumbar disc herniation (LDH) is the most common reason for low back pain in the working society. New regenerative approaches and novel implants are directed towards the restoration of the disc or its biomechanical properties. Aiming to investigate these new therapies under physiological conditions, in this study, a model for LDH was established by developing a new physiological in vitro test method. In 14 human lumbar motion segments, different daily-life and worst-case activities were simulated successfully by applying a physiological range of motion and axial loading in order to create physiological intradiscal pressure. An LDH could be provoked in 11 of the 14 specimens through vertical and round annular defects of different sizes. Interestingly, the defect and the LDH hardly influenced the biomechanical properties of the disc. For the investigation of regenerative approaches in further experiments, the recommendation based on the results of this study is to create an LDH in non-degenerated motion segments by the application of the new physiological in vitro test method after setting the round annular defects to a size of 4 mm in diameter.

scholarly journals Spinal Biomechanical Modelling in the Process of Lumbar Intervertebral Disc Herniation in Middle-Aged and Elderly

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xinyu Zhang ◽  
Zhe Zhao ◽  
Chunlei Niu ◽  
Zengbiao Ma ◽  
Jianlei Hou ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Lumbar Disc Herniation ◽  
Disc Herniation ◽  
Lumbar Disc ◽  
Three Dimensional ◽  
Biomechanical Properties ◽  
Lumbar Spine Surgery ◽  
Articular Process ◽  
Lower Lumbar Spine

Lumbar disc herniation is one of the common clinical diseases of the lower lumbar spine in orthopedics. The purpose is to remove the herniated disc nucleus pulposus tissue, remove the compressed part of the disease, and relieve symptoms, such as nerve pain. In the past, biomechanics research mostly relied on in vitro measurements, but the complicated internal environment of the human body prevented us from further measurement and research. However, with the development of computer technology, the use of computer CT scanning, software three-dimensional reconstruction, and displacement study three-dimensional spine biomechanics method makes the research of biomechanics into in vitro simulation stage and has gradually become the focus of current research. The postoperative biomechanics was simulated and the comparison model was established at the same time. At the same time, we combined the clinical follow-up data and studied the clinical data for the treatment of postoperative recurrence of lumbar disc herniation. We compared and analyzed the initial operation method and the experimental results and obtained the prevention of recurrence. The results showed that when one inferior articular process was removed, the lumbar spine appeared unstable to rotate to the opposite side; when one inferior articular process was completely removed, the movement of the lumbar spine in all directions was unstable. Better research on the biomechanical properties of the spine will help the diagnosis and treatment of clinical lumbar disc herniation. Therefore, when performing posterior lumbar spine surgery, not only should the exposure of the surgical field and thorough decompression be considered, but also the biomechanical properties of the lumbar spine should be comprehensively evaluated.

scholarly journals Activity of Ceftaroline against Aerobic Gram-Positive and Gram-Negative Pathogens: Effect of Test Method Variability

2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Diane M. Citron ◽  
Yumi A. Warren ◽  
Kerin L. Tyrrell ◽  
Ellie J. C. Goldstein
Keyword(s):  
Bactericidal Activity ◽  
Test Method ◽  
In Vitro Test ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
E Coli ◽  
Minimum Inhibitory Concentrations ◽  
Test Conditions ◽  
Vitro Test

Ceftaroline is a new cephalosporin with bactericidal activity against methicillin-resistant S. aureus (MRSA) as well as gram-negative pathogens. Variations of in vitro test conditions were found to affect ceftaroline activity, with 5% NaCl inhibiting growth and/or reducing the minimum inhibitory concentrations (MICs) for E. coli, K. pneumoniae, M. catarrhalis, H. influenzae, and streptococci, while an inoculum of 106 CFU/mL raised MICs of some E. coli, K. pneumoniae, and M. catarrhalis strains.

scholarly journals Development of an in vitro test procedure for the characterization of left atrial appendage occluder devices

2019 ◽  
Vol 5 (1) ◽  
pp. 461-463
Author(s):  
Finja Borowski ◽  
Sebastian Kaule ◽  
Stefan Siewert ◽  
Klaus-Peter Schmitz ◽  
Michael Stiehm ◽  
...  
Keyword(s):  
Left Atrial ◽  
Left Atrial Appendage ◽  
Standardized Test ◽  
Test Procedure ◽  
Test Method ◽  
Atrial Appendage ◽  
In Vitro Test ◽  
Watchman Device ◽  
Vitro Test

AbstractThe implantation of an occluder in the left atrial appendage (LAA) is an emerging therapy for the treatment of patients suffering from atrial fibrillation and with a contraindication to oral anticoagulation. The LAA occluder (LAAO) provides a reduction of the potential risk of strokes by thromboembolism. Currently, only a few CE-approved devices are available on the market and the number of clinical trials is comparatively low. Furthermore, there is currently no standardized test method available for testing functionality of the occluder, especially for testing safe anchorage and permeability. Therefore, the aim of this study is to establish an in vitro test method to prove anchorage mechanism and permeability regarding thromboembolism of the LAAO under physiological conditions. A standardized technical and fully parameterized silicone model of a LAA, based on studies of different morphologies and sizes, was developed. The LAA model was mounted onto the left atrial chamber of a commercial pulse duplicator system to simulate physiological hemodynamic conditions. The test was performed using the Watchman device (Boston Scientific, USA; size: 31 mm). The inner implantation diameter of the LAA model was designed according to a target compression of 10% for the Watchman device in the implanted configuration. Furthermore, thrombus-like particles (n=150, d=1,7±0,05 mm) were added to represent the flushing of thrombi out of the LAA after device implantation. Within several cycles it was confirmed that no particles were washed out of the LAA model with the implanted occluder leading to a full protection against thromboembolism. It could also be shown that the occluder is firmly anchored in the LAA. Pressure measurements with sensors in the left atrium and in the LAA distal to the occluder could also show that the occluder has no influence on the pressure conditions in the LAA.

Use of in vitro test method as applied to denture surface identification

1975 ◽  
Vol 33 (4) ◽  
pp. 454-457 ◽  
Author(s):  
Laurence D. Johns ◽  
Malcolm E. Boone ◽  
James E. House
Keyword(s):  
Test Method ◽  
In Vitro Test ◽  
Vitro Test

scholarly journals A standardised in vivo and in vitro test method for evaluating tick repellents

2013 ◽  
Vol 107 (2) ◽  
pp. 160-168 ◽  
Author(s):  
T. Kröber ◽  
M. Bourquin ◽  
P.M. Guerin
Keyword(s):  
Test Method ◽  
In Vitro Test ◽  
Vitro Test ◽  
Tick Repellents

In vitro assessment of water resistance of sun care products: a reproducible and optimized in vitro test method

2007 ◽  
Vol 29 (6) ◽  
pp. 451-460 ◽  
Author(s):  
M. Pissavini ◽  
V. Alard ◽  
U. Heinrich ◽  
K. Jenni ◽  
V. Perier ◽  
...  
Keyword(s):  
Water Resistance ◽  
Test Method ◽  
In Vitro Test ◽  
Vitro Test ◽  
In Vitro Assessment
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