[Show abstract][Hide abstract] ABSTRACT: Osteoarthritis (OA) is a major joint disease in humans and many other animals. Consequently, medical countermeasures for OA have been investigated diligently. This study was designed to examine the regeneration of articular cartilage and subchondral bone using three-dimensional (3D) constructs of adipose tissue-derived mesenchymal stem cells (AT-MSCs).
AT-MSCs were isolated and expanded until required for genetical and immunological analysis and construct creation. A construct consisting of about 760 spheroids that each contained 5.0 × 104 autologous AT-MSCs was implanted into an osteochondral defect (diameter: 4 mm; depth: 6 mm) created in the femoral trochlear groove of two adult microminipigs. After implantation, the defects were monitored by computed tomography every month for 6 months in animal no. 1 and 12 months in animal no. 2.
AT-MSCs were confirmed to express the premature genes and to be positive for CD90 and CD105 and negative for CD34 and CD45. Under specific nutrient conditions, the AT-MSCs differentiated into osteogenic, chondrogenic, and adipogenic lineages, as evidenced by the expressions of related marker genes and the production of appropriate matrix molecules. A radiopaque area emerged from the boundary between the bone and the implant and increased more steadily upward and inward for the implants in both animal no. 1 and animal no. 2. The histopathology of the implants after 6 months revealed active endochondral ossification underneath the plump fibrocartilage in animal no. 1. The histopathology after 12 months in animal no. 2 showed not only that the diminishing fibrocartilage was as thick as the surrounding normal cartilage but also that massive subchondral bone was present.
The present results suggest that implantation of a scaffold-free 3D construct of AT-MSCs into an osteochondral defect may induce regeneration of the original structure of the cartilage and subchondral bone over the course of 1 year, although more experimental cases are needed.
Preview · Article · Dec 2015 · Journal of Orthopaedic Surgery and Research
[Show abstract][Hide abstract] ABSTRACT: Cartilage regeneration with cell therapy following arthroscopic surgery could be used in racehorses with intra-articular fractures (IAF) and osteochondritis dissecans (OCD). The aims of this study were to investigate the origin and multipotency of stromal cells in the synovial fluid (SF) of horses with intra-articular injury and synovitis, and to provide a new strategy for regeneration of lost articular cartilage. Mesenchymal stromal cells were isolated from SF of horses with IAF and OCD. Multipotency was analysed by RT-PCR for specific mRNAs and staining for production of specific extracellular matrices after induction of differentiation. The total number of SF-derived mesenchymal stromal cells reached >1 × 107 by the fourth passage. SF-derived cells were strongly positive (>90% cells positive) for CD44, CD90 and major histocompatibility complex (MHC) class I, and moderately positive (60–80% cells positive) for CD11a/CD18, CD105 and MHC class II by flow cytometry. SF-derived cells were negative for CD34 and CD45. Under specific nutrient conditions, SF-derived cells differentiated into osteogenic, chondrogenic, adipogenic and tenogenic lineages, as indicated by the expression of specific marker genes and by the production of specific extracellular matrices. Chondrogenic induction in culture resulted in a change in cell shape to a ‘stone-wall’ appearance and formation of a gelatinous sheet that was intensely stained with Alcian blue. SF may be a novel source of multipotent mesenchymal stem cells with the ability to regenerate chondrocytes.
No preview · Article · Oct 2014 · The Veterinary Journal
[Show abstract][Hide abstract] ABSTRACT: A 10-year-old, neutered male Labrador retriever presented with progressive left
hind lameness. Ultrasonography revealed large, subcutaneous, ovoid cysts around the stifle
joint. Radiographic and computed tomographic images revealed periosteal reaction of the
distal femur. Magnetic resonance (MR) imaging showed a large cyst that was hypointense in
T1-weighted images, hyperintense in T2-weighted images and had a thin lining that was
enhanced by intravenous gadonium injection. The cyst communicated with the joint cavity
and other small cysts around the joint. Histopathology of an excisional biopsy specimen
led to diagnosis of ganglion cyst. This report provides MR images of a ganglion cyst in a
Preview · Article · Nov 2013 · Journal of Veterinary Medical Science
[Show abstract][Hide abstract] ABSTRACT: We hypothesized that semi-quantitative determinations of changeable blood flows in granulation and scar tissues during tendon healing could be helpful for differentiation between the acute phase rich in blood vessels and the remodeling phase with fewer vessels. Ten Thoroughbreds with injured superficial digital flexor tendon (SDFT) in a forelimb were used for evaluation of blood flows in the injured tendons of racehorses using color Doppler (CD) ultrasonography. Using longitudinal CD images, features of maximum color activities were defined. These were rhythmically blinking, tiny to small signals (grade 1), pulsatile expanded dots (grade 2), and dynamic streams (grade 3). Grade of color activity in CD ultrasonography could be useful for quantitative assessment of equine SDFT repair.
No preview · Article · Jul 2012 · Journal of Veterinary Medical Science
[Show abstract][Hide abstract] ABSTRACT: A 12-year-old neutered male shih tzu developed progressive pelvic limb paraparesis. Computed tomography showed a radiolucent mass lesion in the spinal canal at the left side of the 11th thoracic vertebra. The mass was not enhanced by intravenous contrast medium injection. It was hyperintense on both T1- and T2-weighted magnetic resonance images. The signal intensity of the mass was decreased with a fat suppression technique, indicating a fatty origin. After removal of the mass via T11-T12 hemilaminectomy, chronic panniculitis was confirmed by histopathological examination. This case demonstrates the utility of computed tomography and magnetic resonance imaging for the diagnosis of spinal canal pyogranulomatous inflammation.
No preview · Article · Feb 2012 · Journal of Veterinary Medical Science