evaluation-stem-cell-therapies-bilateral-patellar-tendon-injury-model

Evaluation of Stem Cell Therapies in a Bilateral Patellar Tendon Injury Model in Rats

Regenerative medicine provides novel alternatives to conditions that challenge traditional treatments. The prevalence and morbidity of tendinopathy across ...

Western University of Health Sciences

To characterize the gait of small-breed dogs walked on a pressure walkway by handlers moving at a metronome-set tempo and to determine the influence of handler and leash side on gait characteristics.

Influence of leash side and handlers on pressure mat analysis of gait characteristics in small-breed dogs.

The objective of this study was to subjectively evaluate the harvest of two areas of adipose collection and three areas of bone marrow collection as potential sites for clinical harvest of adipose stromal vascular fraction (SVF) and bone marrow concentrate for clinical use by quantifying the amount of tissue harvested, subjective ease of harvest, the variation of each site, and determining the cell surface marker characteristics using commercially available antibodies. Bone marrow and adipose tissue samples were collected from 10 adult mixed breed dogs. Adipose tissue was collected from the caudal scapular region and falciform fat ligament. Bone marrow aspirates were collected from the ilium, humerus, and tibia. Tissues were weighed (adipose) or measured by volume (bone marrow), processed to isolate the SVF or bone marrow concentrate, and flow cytometry was performed to quantitate the percentage of cells that were CD90, CD44 positive, and CD45 negative. Sites and tissue types were compared using matched pairs t-test. Subjectively subcutaneous fat collection was the most difficult and large amounts of tissue dissection were necessary. Additionally the subcutaneous area yielded less than the goal amount of tissue. The bone marrow harvest ranged from 10 to 27.5 ml. Adipose tissue had the highest concentration of cells with CD90(+), CD44(+), and CD45(-) markers (P < 0.05), and bone marrow had the highest total number of these cells at harvest (P < 0.05). Variation was high for all sites, but the adipose collection yielded more consistent results. These results describe the relative cellular components in the SVF of adipose tissue and bone marrow as defined by the biomarkers chosen. Although bone marrow yielded higher absolute cell numbers on average, adipose tissue yielded more consistent results. Fat from the falciform ligament was easily obtained with less dissection and therefore created less perceived relative patient trauma.

Comparison of Mesenchymal Stem Cell Surface Markers from Bone Marrow Aspirates and Adipose Stromal Vascular Fraction Sites.

To determine the association of a radiographic score derived from tibial plateau angle (TPA) and femoral anteversion (FAA) with an outcome of cranial cruciate ligament deficiency (CCLD) in large dogs.

Evaluation of a scoring system based on conformation factors to predict cranial cruciate ligament disease in Labrador Retrievers.

Chitosan is attractive as a substrate for stem cell expansion because it improves stemness through formation of spheroids. Hypoxia has also been proposed as a strategy to enhance stemness and survival of stem cells after in vivo implantation. This study was therefore designed to evaluate the influence of hypoxia on chitosan-induced behavior of stem cells. Umbilical cord matrix-derived stem cells were cultured on chitosan film or standard plate under normoxia and hypoxia, for 3 and 7 days. Based on immunophenotyping, chitosan strongly suppresses the expression of CD90 and CD105 cell surface markers, changes partially reversed by combined exposure to hypoxia. Hypoxia generally increased the volume and number of spheroids formed on chitosan, but the cellularity of cultures on chitosan films remained lower than that of standard plates. After 7 days of culture, the expression of stemness related genes (Oct4, Sox2, and Nanog) was best stimulated by combined exposure to chitosan and hypoxia. Based on our results, conditioning stem cells for 7 days on chitosan films under hypoxic conditions is recommended to enhance the stemness of stem cells, and minimize cell loss due to lack of attachment on chitosan. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 501-511, 2018.

Influence of hypoxia on the stemness of umbilical cord matrix-derived mesenchymal stem cells cultured on chitosan films.

We recently reported that a conformation score derived from the tibial plateau angle (TPA) and the femoral anteversion angle (FAA), best discriminates limbs predisposed to, or affected by cranial cruciate ligament disease (CCLD), from those that are at low risk for CCLD. The specificity and sensitivity of this score were high enough to support further investigations toward its use for large-scale screening of dogs by veterinarians. The next step, which is the objective of the current study, is to determine inter-observer variability of that CCLD score in a large population of Labrador Retrievers. A total of 167 Labradors were enrolled in this cross-sectional study. Limbs of normal dogs over 6 years of age with no history of CCLD were considered at low risk for CCLD. Limbs of dogs with CCLD were considered at high risk for CCLD. Tibial plateau and femoral anteversion angles were measured independently by two investigators to calculate a CCLD score for each limb. Kappa statistics were used to determine the extent of agreement between investigators. Pearson's correlation and intraclass coefficients were calculated to evaluate the correlation between investigators and the relative contribution of each measurement to the variability of the CCLD score.

Factors contributing to the variability of a predictive score for cranial cruciate ligament deficiency in Labrador Retrievers.

To determine repeatability of and correlation between 2 radiographic measurements of femoral anteversion angles (FAA) and to determine their influence on a score derived from tibial plateau angle (TPA) and FAA to predict the risk of cranial cruciate ligament disease (CCLD).

Influence of radiographic techniques on the measurement of femoral anteversion angles and a conformation score of pelvic limbs in Labrador retrievers.

To characterize radioulnar incongruence (RUI) in large dogs with medial coronoid disease (MCD) and determine the agreement between radiography, computed tomography (CT), and arthroscopy.

Article	Year
Influence of leash side and handlers on pressure mat analysis of gait characteristics in small-breed dogs. Journal of the American Veterinary Medical Association\| PubMed ID: 25970218	2015
Comparison of Mesenchymal Stem Cell Surface Markers from Bone Marrow Aspirates and Adipose Stromal Vascular Fraction Sites. Frontiers in veterinary science\| PubMed ID: 26835460	2015
Evaluation of a scoring system based on conformation factors to predict cranial cruciate ligament disease in Labrador Retrievers. Veterinary surgery : VS\| PubMed ID: 28029702	2017
Influence of hypoxia on the stemness of umbilical cord matrix-derived mesenchymal stem cells cultured on chitosan films. Journal of biomedical materials research. Part B, Applied biomaterials\| PubMed ID: 28188976	2018
Factors contributing to the variability of a predictive score for cranial cruciate ligament deficiency in Labrador Retrievers. BMC veterinary research\| PubMed ID: 28806971	2017
Influence of radiographic techniques on the measurement of femoral anteversion angles and a conformation score of pelvic limbs in Labrador retrievers. Veterinary surgery : VS\| PubMed ID: 29532499	2018
Radiographic, computed tomographic, and arthroscopic diagnosis of radioulnar incongruence in dogs with medial coronoid disease. Veterinary surgery : VS\| PubMed ID: 29536555	2018

Dominique J. Griffon

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