Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 51
Filter
Add more filters










Publication year range
1.
Biofabrication ; 16(2)2024 02 09.
Article in English | MEDLINE | ID: mdl-38306679

ABSTRACT

Although three-dimensional (3D) printing techniques are used to mimic macro- and micro-structures as well as multi-structural human tissues in tissue engineering, efficient target tissue regeneration requires bioactive 3D printing scaffolds. In this study, we developed a bone morphogenetic protein-2 (BMP-2)-immobilized polycaprolactone (PCL) 3D printing scaffold with leaf-stacked structure (LSS) (3D-PLSS-BMP) as a bioactive patient-tailored bone graft. The unique LSS was introduced on the strand surface of the scaffold via heating/cooling in tetraglycol without significant deterioration in physical properties. The BMP-2 adsorbed on3D-PLSS-BMPwas continuously released from LSS over a period of 32 d. The LSS can be a microtopographical cue for improved focal cell adhesion, proliferation, and osteogenic differentiation.In vitrocell culture andin vivoanimal studies demonstrated the biological (bioactive BMP-2) and physical (microrough structure) mechanisms of3D-PLSS-BMPfor accelerated bone regeneration. Thus, bioactive molecule-immobilized 3D printing scaffold with LSS represents a promising physically and biologically activated bone graft as well as an advanced tool for widespread application in clinical and research fields.


Subject(s)
Osteogenesis , Tissue Scaffolds , Humans , Tissue Scaffolds/chemistry , Tissue Engineering/methods , Bone Regeneration , Polyesters/chemistry , Printing, Three-Dimensional
2.
ACS Biomater Sci Eng ; 8(12): 5233-5244, 2022 Dec 12.
Article in English | MEDLINE | ID: mdl-36384281

ABSTRACT

Even though bony defects can be recovered to their original condition with full functionality, critical-sized bone injuries continue to be a challenge in clinical fields due to deficiencies in the scaffolding matrix and growth factors at the injury region. In this study, we prepared bone morphogenetic protein-2 (BMP-2)-loaded porous particles as a bioactive bone graft for accelerated bone regeneration. The porous particles with unique leaf-stacked morphology (LSS particles) were fabricated by a simple cooling procedure of hot polycaprolactone (PCL) solution. The unique leaf-stacked structure in the LSS particles provided a large surface area and complex release path for the sufficient immobilization of BMP-2 and sustained release of BMP-2 for 26 days. The LSS was also recognized as a topographical cue for cell adhesion and differentiation. In in vitro cell culture and in vivo animal study using a canine mandible defect model, BMP-2-immobilized LSS particles provided a favorable environment for osteogenic differentiation of stem cells and bone regeneration. In vitro study suggests a dual stimulus of bone mineral-like (leaf-stacked) structure (a physical cue) and continuously supplied BMP-2 (a biological cue) to be the cause of this improved healing outcome. Thus, LSS particles containing BMP-2 can be a promising bioactive grafting material for effective new bone formation.


Subject(s)
Bone Regeneration , Osteogenesis , Animals , Dogs , Porosity
3.
Vet Q ; 42(1): 41-47, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35068361

ABSTRACT

Bacillus amyloliquefaciens is a gram-positive bacterial species that is utilised as a probiotic in humans and animals. There are no reports of infective endocarditis (IE) in dogs. An 8-year-old, spayed, female Maltese presented with a 1-month history of fever, depression, weight loss, and hindlimb lameness. Laboratory test results indicated non-regenerative anaemia, neutrophilia, hyperglobulinemia, and proteinuria. Echocardiography revealed vegetation on the septal leaflet of the mitral valve and thromboemboli in the left atrium. Consecutive blood culture results revealed that the blood samples were consistently positive for Bacillus amyloliquefaciens, which is generally considered a probiotic bacterial species for animals. Broad-spectrum antibiotics (amoxicillin-clavulanic acid and cefotaxime) and anticoagulants (clopidogrel and rivaroxaban) were administered for 4 months. The clinical signs were responsive to antibiotic treatment. After 4 months, the dog was no longer febrile and the size of the thromboemboli in the left atrium had decreased. Bacteria were no longer isolated in blood cultures after antibiotic therapy. To the best of our knowledge, this is the first case report of canine IE caused by bactaeremic infection with Bacillus amyloliquefaciens.


Subject(s)
Bacillus amyloliquefaciens , Dog Diseases , Endocarditis, Bacterial , Endocarditis , Animals , Anti-Bacterial Agents/therapeutic use , Dog Diseases/drug therapy , Dogs , Echocardiography , Endocarditis/drug therapy , Endocarditis/veterinary , Endocarditis, Bacterial/drug therapy , Endocarditis, Bacterial/veterinary , Female , Mitral Valve/diagnostic imaging
4.
Biomacromolecules ; 21(12): 4795-4805, 2020 12 14.
Article in English | MEDLINE | ID: mdl-32955865

ABSTRACT

Although biological therapies based on growth factors and transplanted cells have demonstrated some positive outcomes for intervertebral disc (IVD) regeneration, repeated injection of growth factors and cell leakage from the injection site remain considerable challenges for human therapeutic use. Herein, we prepare human bone marrow-derived mesenchymal stem cells (hBMSCs) and transforming growth factor-ß3 (TGF-ß3)-loaded porous particles with a unique leaf-stack structural morphology (LSS particles) as a combination bioactive delivery matrix for degenerated IVD. The LSS particles are fabricated with clinically acceptable biomaterials (polycaprolactone and tetraglycol) and procedures (simple heating and cooling). The LSS particles allow sustained release of TGF-ß3 for 18 days and stable cell adhesiveness without additional modifications of the particles. On the basis of in vitro and in vivo studies, it was observed that the hBMSCs/TGF-ß3-loaded LSS particles can provide a suitable milieu for chondrogenic differentiation of hBMSCs and effectively induce IVD regeneration in a beagle dog model. Thus, therapeutically loaded LSS particles offer the promise of an effective bioactive delivery system for regeneration of various tissues including IVD.


Subject(s)
Intervertebral Disc , Mesenchymal Stem Cells , Regeneration , Transforming Growth Factor beta3/pharmacology , Animals , Cell Differentiation , Dogs , Humans , Porosity
5.
BMC Vet Res ; 16(1): 192, 2020 Jun 12.
Article in English | MEDLINE | ID: mdl-32532259

ABSTRACT

BACKGROUND: Combination therapy with glucocorticoids and adjunctive immunomodulating drugs has been generally accepted as a standard treatment regimen for meningoencephalomyelitis of unknown etiology (MUE). We hypothesized that treatment with MMF as an adjunctive agent along with glucocorticoids would be effective and well-tolerated protocol in dogs with MUE. Eighty-six dogs with MUE between May 2009 and June 2017 were included (59 females and 27 males; mean age of 5.93 years; mean body weight of 3.83 kg). The medical records of dogs with MUE treated with prednisolone and MMF were retrospectively evaluated to determine the therapeutic response, survival time, and treatment-related adverse effects. RESULTS: A partial or complete response (CR) was recorded for 75 dogs. The overall median survival time from the initiation of treatment was 558 days. Dogs that showed CR with no relapse over the treatment period (from diagnosis to death) had significantly longer median survival times. A significantly higher mortality hazard ratio of 4.546 was recorded in dogs that failed to achieve CR. The interval between the onset of clinical signs and the clinical presentation was not significantly associated with CR, relapse rate, and survival time. Adverse effects included gastrointestinal upsets in 26 dogs (30.23%), sporadic infections in 17 dogs (19.77%), and pancreatitis in seven dogs (8.14%). CONCLUSIONS: The results suggest that adjunctive MMF treatment for MUE is safe and comparable to other immunosuppressive protocols. The treatment should focus on the achievement of CR and preventing relapse for successful management.


Subject(s)
Dog Diseases/drug therapy , Meningoencephalitis/veterinary , Mycophenolic Acid/therapeutic use , Prednisolone/therapeutic use , Animals , Anti-Inflammatory Agents/therapeutic use , Dogs , Drug Therapy, Combination/veterinary , Female , Immunosuppressive Agents/therapeutic use , Male , Meningoencephalitis/drug therapy , Meningoencephalitis/mortality , Mycophenolic Acid/adverse effects , Prednisolone/adverse effects , Recurrence , Retrospective Studies , Treatment Outcome
6.
J Wildl Dis ; 56(4): 950-952, 2020 10 01.
Article in English | MEDLINE | ID: mdl-32402232

ABSTRACT

Thymic hematomas are uncommon in animals, and the few reported cases are all in dogs. In May 2019, we necropsied a wild Eurasian otter (Lutra lutra) in Junju, Republic of Korea, and found a thymic hematoma without any signs of trauma or hemorrhage in other organs, except for a hemothorax. This study describes the macroscopic and microscopic examinations of a thymic hematoma in an Eurasian otter.


Subject(s)
Hematoma/veterinary , Hemorrhage/veterinary , Otters , Thymus Gland/pathology , Animals , Fatal Outcome , Hematoma/diagnosis , Hematoma/pathology , Hemorrhage/pathology , Male
7.
J Vet Sci ; 20(4): e44, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31364328

ABSTRACT

This study evaluated the feasibility of using texture analysis and machine learning to distinguish radiographic lung patterns. A total of 1200 regions of interest (ROIs) including four specific lung patterns (normal, alveolar, bronchial, and unstructured interstitial) were obtained from 512 thoracic radiographs of 252 dogs and 65 cats. Forty-four texture parameters based on eight methods of texture analysis (first-order statistics, spatial gray-level-dependence matrices, gray-level-difference statistics, gray-level run length image statistics, neighborhood gray-tone difference matrices, fractal dimension texture analysis, Fourier power spectrum, and Law's texture energy measures) were used to extract textural features from the ROIs. The texture parameters of each lung pattern were compared and used for training and testing of artificial neural networks. Classification performance was evaluated by calculating accuracy and the area under the receiver operating characteristic curve (AUC). Forty texture parameters showed significant differences between the lung patterns. The accuracy of lung pattern classification was 99.1% in the training dataset and 91.9% in the testing dataset. The AUCs were above 0.98 in the training set and above 0.92 in the testing dataset. Texture analysis and machine learning algorithms may potentially facilitate the evaluation of medical images.


Subject(s)
Lung/diagnostic imaging , Machine Learning , Radiography/veterinary , Algorithms , Animals , Area Under Curve , Cats , Dogs , Female , Male , ROC Curve , Radiography/methods
8.
J Biomed Mater Res A ; 107(10): 2183-2194, 2019 10.
Article in English | MEDLINE | ID: mdl-31116505

ABSTRACT

Hypoxia and limited vascularization inhibit bone growth and recovery after surgical debridement to treat osteomyelitis. Similarly, despite significant efforts to create functional tissue-engineered organs, clinical success is often hindered by insufficient oxygen diffusion and poor vascularization. To overcome these shortcomings, we previously used the oxygen carrier perfluorooctane (PFO) to develop PFO emulsion-loaded hollow microparticles (PFO-HPs). PFO-HPs act as a local oxygen source that increase cell viability and maintains the osteogenic differentiation potency of human periosteum-derived cells (hPDCs) under hypoxic conditions. In the present study, we used a miniature pig model of mandibular osteomyelitis to investigate bone regeneration using hPDCs seeded on PFO-HPs (hPDCs/PFO-HP) or hPDCs seeded on phosphate-buffered saline (PBS)-HPs (hPDCs/PBS-HP). Osteomyelitis is characterized by a series of microbial invasion, vascular disruption, bony necrosis, and sequestrum formation due to impaired host defense response. Sequential plain radiography, computed tomography (CT), and 3D reconstructed CT images revealed new bone formation was more advanced in defects that had been implanted with the hPDCs/PFO-HPs than in defects implanted with the hPDCs/PBS-HP. Thus, PFO-HPs are a promising tissue engineering approach to repair challenging bone defects and regenerate structurally organized bone tissue with 3D architecture.


Subject(s)
Bone Regeneration/physiology , Mandible/pathology , Microspheres , Osteoblasts/cytology , Osteomyelitis/therapy , Oxygen/pharmacology , Periosteum/cytology , Animals , Bone Regeneration/drug effects , Buffers , Disease Models, Animal , Fluorocarbons/chemistry , Humans , Mandible/diagnostic imaging , Mandible/drug effects , Mandible/microbiology , Osteoblasts/drug effects , Osteogenesis/drug effects , Osteomyelitis/diagnostic imaging , Osteomyelitis/microbiology , Osteomyelitis/pathology , Prosthesis Implantation , Staphylococcus aureus/drug effects , Swine , Swine, Miniature
9.
Biomacromolecules ; 20(2): 1087-1097, 2019 02 11.
Article in English | MEDLINE | ID: mdl-30642156

ABSTRACT

Sufficient oxygen delivery into tissue-engineered three-dimensional (3D) scaffolds to produce clinically applicable tissues/organs remains a challenge for researchers and clinicians. One potential strategy to overcome this limitation is the use of an oxygen releasing scaffold. In the present study, we prepared hollow microparticles (HPs) loaded with an emulsion of the oxygen carrier perfluorooctane (PFO; PFO-HPs) for the timely supply of oxygen to surrounding cells. These PFO-HPs prolonged the survival and preserved the osteogenic differentiation potency of human periosteal-derived cells ( hPDCs) under hypoxia. hPDCs seeded onto PFO-HPs formed new bone at a faster rate and with a higher bone density than hPDCs seeded onto phosphate buffered saline-loaded control HPs. These findings suggest that PFO-HPs provide a suitable environment for the survival and maintenance of differentiation ability of hPDCs at bony defects without vascular networks until new blood vessel ingrowth occurs, thus enhancing bone regeneration. PFO-HPs are a promising system for effective delivery of various functional cells, including stem cells and progenitor cells, to regenerate damaged tissues/organs.


Subject(s)
Bone Regeneration/drug effects , Cell Differentiation/drug effects , Cell Survival/drug effects , Hypoxia/drug therapy , Oxygen/pharmacology , Cells, Cultured , Humans , Osteogenesis/drug effects , Stem Cells/drug effects , Tissue Engineering/methods , Tissue Scaffolds
10.
ACS Appl Mater Interfaces ; 10(25): 21091-21102, 2018 Jun 27.
Article in English | MEDLINE | ID: mdl-29863327

ABSTRACT

Sustained release of bioactive molecules from delivery systems is a common strategy for ensuring their prolonged bioactivity and for minimizing safety issues. However, residual toxic reagents, the use of harsh organic solvents, and complex fabrication procedures in conventional delivery systems are considered enormous impediments toward clinical use. Herein, we describe bone morphogenetic protein-2 (BMP-2)-immobilized porous polycaprolactone particles with unique leaf-stacked structures (LSS particles) prepared using clinically feasible materials and procedures. The BMP-2 immobilized in these LSS particles is continuously released up to 36 days to provide an appropriate environment for osteogenic differentiation of human periosteum-derived cells and new bone formation. Thus, the leaf-stacked structures of these LSS particles provide a simple but clinically applicable platform for effectively delivering a variety of bioactive molecules, such as growth factors, hormones, cytokines, peptides, etc.


Subject(s)
Delayed-Action Preparations , Bone Morphogenetic Protein 2 , Bone Regeneration , Humans , Osteogenesis , Periosteum , Porosity , Tissue Scaffolds
11.
J Vet Med Sci ; 79(9): 1532-1539, 2017 Sep 12.
Article in English | MEDLINE | ID: mdl-28757523

ABSTRACT

The present study aimed to investigate the technical feasibility of percutaneous endoscopic mini-hemilaminectomy via a uniportal approach, and to evaluate the possibility of decompression and endoscopic examination of the thoracic and lumbar spinal canals in small dogs during such procedures. Fresh canine cadavers of mixed-breed dogs (n=7) were used in this study. Following injection of a barium and agarose mixture (BA-gel) to stimulate intervertebral disc herniation, percutaneous endoscopic mini-hemilaminectomy was performed using a lateral approach to the thoracic and lumbar vertebrae. BA-gel was removed to decompress the spinal cord using an elevator and rongeurs after mini-hemilaminectomy. Pre and post-operative computed tomography (CT) scans were obtained to evaluate surgical outcomes. Intra-operative complications, incision length, and procedure time were recorded. All procedures were completed with clear visualization of the spinal cord and floor of the spinal canal. The mean total operating time was 58.00 ± 18.06 min. Lengths of incision were under 1 cm in all dogs. Intra-operative complications included iatrogenic nerve root injuries caused by the micro-rongeur in two dogs. CT imaging revealed that removal of BA-gel resulted in sufficient spinal cord decompression. Our findings indicated that percutaneous endoscopic thoracolumbar mini-hemilaminectomy is feasible for spinal cord decompression and allows for adequate observation of the spinal canal. Thus, this technique may be an alternative surgical option for treatment of thoracolumbar disk disease in dogs.


Subject(s)
Dog Diseases/surgery , Endoscopy/veterinary , Intervertebral Disc Displacement/veterinary , Laminectomy/veterinary , Animals , Barium Sulfate , Cadaver , Disease Models, Animal , Dogs , Endoscopy/adverse effects , Endoscopy/methods , Feasibility Studies , Intervertebral Disc Displacement/surgery , Laminectomy/adverse effects , Laminectomy/methods , Neuroendoscopy/adverse effects , Neuroendoscopy/methods , Neuroendoscopy/veterinary , Sepharose , Tomography, X-Ray Computed/veterinary
12.
J Biomed Mater Res A ; 105(2): 363-376, 2017 02.
Article in English | MEDLINE | ID: mdl-27643840

ABSTRACT

Polycaprolactone (PCL) is a biodegradable polyester that is bioresorbable and biocompatible, and is widely used in medical fields. This study examines in vitro and in vivo osteogenic activities of cultured human periosteum-derived osteoblasts (POs) seeded into growth factor (bone morphogenic protein 2 [BMP-2] or vascular endothelial growth factor [VEGF])-releasing scaffolds of PCL beads coated with Pluronic F127. Each growth factor immobilized in the PCL/F127 is cumulatively released from the beads for more than 40 days (up to 3.04 ± 0.08 ng mg-1 BMP-2 and 3.41 ± 0.18 ng mg-1 VEGF in 42 days). Long-term (∼2 years) experimental results obtained in a miniature pig model suggest that POs seeded into BMP-2 + VEGF-releasing PCL/P-F127 beads are the most effective for bone repair. In in vitro assays, osteogenic activities were higher in POs seeded into BMP-2-releasing PCL/Pluronic F127 beads at earlier time points and in POs seeded into BMP-2 + VEGF-releasing PCL/Pluronic F127 beads at later time points. These results suggest that the combination of BMP-2 and VEGF more sufficiently stimulates (in particular at late time points) osteoblast differentiation of POs seeded in the PCL/F127 in vitro and in vivo, and thus allows effective bone regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 363-376, 2017.


Subject(s)
Bone Morphogenetic Protein 2/chemistry , Osteoblasts/metabolism , Osteogenesis , Periosteum/metabolism , Poloxamer/chemistry , Polyesters/chemistry , Tissue Scaffolds/chemistry , Vascular Endothelial Growth Factor A/chemistry , Animals , Female , Humans , Male , Osteoblasts/cytology , Periosteum/cytology , Swine , Swine, Miniature
13.
J Vet Med Sci ; 79(1): 160-165, 2017 Jan 20.
Article in English | MEDLINE | ID: mdl-27725351

ABSTRACT

Anesthesia is an inevitably important component of diagnosis and treatments examining the health condition of wild animals. Not only does anesthesia become an essential tool in minimizing stress of the patients and providing an opportunity to deliver accurate and safe procedures, but it also ensures the safety of the medical crew members. This study was conducted to investigate the dose-response cardiorespiratory effects of isoflurane during spontaneous ventilation in ten cinereous vultures. Each bird was administered isoflurane at initial concentration of 1.0, 1.5, 2.0, 2.5 and 3.0 and then an end-tidal isoflurane concentrations (ETiso) of 1.0% for an equilibration period of 15 min in the given order. At the end of the equilibration period, the direct blood pressure (BP), heart rate (HR), respiratory rate (RR) and end tidal CO2 partial pressure (PETCO2) were recorded, and blood gas analysis was performed. Increasing isoflurane concentrations during spontaneous ventilation led to dose-dependent increases in HR and PETCO2, with minimal changes in RR, decreased arterial BP and respiratory acidosis. Overall, isoflurane for anesthesia of spontaneously breathing cinereous vultures is a suitable choice for diagnostic or surgical procedures.


Subject(s)
Anesthetics, Inhalation/adverse effects , Falconiformes , Isoflurane/adverse effects , Anesthesia/veterinary , Animals , Blood Gas Analysis , Blood Pressure/drug effects , Dose-Response Relationship, Drug , Heart Rate/drug effects , Respiratory Rate/drug effects
14.
Vet Surg ; 45(S1): O84-O94, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27711963

ABSTRACT

OBJECTIVE: To examine the technical feasibility of percutaneous endoscopic pediculectomy using a lateral approach and to evaluate its use for decompression and examination of the thoracic and lumbar spinal canals in small dogs. STUDY DESIGN: Experimental study. ANIMALS: Clinically normal adult dogs (n=10). METHODS: After optimizing the technique in cadavers, percutaneous endoscopic pediculectomy was performed using a lateral approach to the thoracic (T12) or lumbar (L2) vertebrae in 5 dogs each. Using fluoroscopic guidance, a K-wire, dilator, and (cannula) working sleeve were placed. A window for visualizing the spinal cord and floor of the spinal canal was created using a specialized drill, rongeurs, trephine, and elevator. Gait and neurologic status were monitored postoperatively, and computed tomography (CT) and magnetic resonance imaging (MRI) performed. RESULTS: All procedures were completed successfully (T12, 45 ± 13 minutes; L2, 59 ± 14 minutes) with clear observation of the spinal cord and floor of the spinal canal. Normal ambulation was maintained in 9 dogs. One dog in the L2 group had ipsilateral hind limb weakness that resolved within 4 days. One dog in the L2 group suffered a fracture of the accessory process. One dog each in the T12 and L2 groups had hyperintense lesions on T2-weighted MRI images, suspicious of focal edema, which reduced at 4 weeks after initial examination, possibly reflecting gliosis. CONCLUSION: Pediculectomy using a percutaneous endoscopic thoracolumbar lateral approach is feasible, provides a good view of the spinal canal, and may be an alternative for treatment of disk disease in dogs.


Subject(s)
Dogs/surgery , Endoscopy/veterinary , Lumbar Vertebrae/surgery , Postoperative Complications/veterinary , Spinal Canal/surgery , Thoracic Vertebrae/surgery , Animals , Decompression, Surgical/methods , Endoscopy/methods , Magnetic Resonance Imaging/veterinary , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Tomography, X-Ray Computed/veterinary
15.
Biomacromolecules ; 17(5): 1633-42, 2016 05 09.
Article in English | MEDLINE | ID: mdl-27068184

ABSTRACT

It is commonly accepted that the sustained release of bone morphogenetic protein-2 (BMP-2) can enhance bone regeneration and minimize its safety issues. However, little is known regarding the appropriate duration of BMP-2 stimulation for sufficient osteogenic differentiation and new bone formation because of the short half-life of BMP-2 in the physiological environment and the lack of a well-defined delivery matrix that can regulate the release period of BMP-2. In this study, we prepared porous poly(lactic-co-glycolic acid) (PLGA) beads with different surface pore sizes that can regulate the release period of BMP-2 (i.e., 7, 17, and 30 days) while providing the BMP-2 concentration required for bone regeneration. Our findings in both in vitro cell culture and in vivo animal studies using these BMP-2-loaded beads demonstrate that release of BMP-2 within 7 days affects only the initial differentiation of human periosteum-derived cells (hPDCs) and does not significantly enhance their subsequent differentiation into mature functional cells. However, extending the duration of BMP-2 stimulation over 17 days can provide a suitable environment for osteogenic differentiation of hPDCs and new bone formation.


Subject(s)
Bone Morphogenetic Protein 2/metabolism , Bone Regeneration/physiology , Cell Differentiation , Lactic Acid/chemistry , Periosteum/cytology , Polyglycolic Acid/chemistry , Animals , Cells, Cultured , Half-Life , Humans , In Vitro Techniques , Polylactic Acid-Polyglycolic Acid Copolymer , Porosity , Swine , Time Factors
16.
J Vet Sci ; 17(3): 289-97, 2016 Sep 30.
Article in English | MEDLINE | ID: mdl-26726028

ABSTRACT

The expression of immunogenic markers after differentiation of umbilical cord blood (UCB)-derived mesenchymal stem cells (MSC) has been poorly investigated and requires extensive in vitro and in vivo testing for clinical application. The expression of human leukocyte antigen (HLA) classes on UCB-derived MSC was tested by Fluorescence-activated cell sorting analysis and immunocytochemical staining. The undifferentiated MSC were moderately positive for HLA-ABC, but almost completely negative for HLA-DR. The MSC differentiated to chondrocytes expressed neither HLA-ABC nor HLA-DR. The proliferation of MSC was not significantly affected by the allogeneic lymphocytes stimulated with concanavalin A. The responder lymphocytes showed no significant decrease in proliferation in the presence of the MSC, but the apoptosis rate of the lymphocytes was increased in the presence of MSC. Taken together, these findings indicate that UCB-derived MSC differentiated to chondrocytes expressed less HLA class I and no class II antigens. The MSC showed an immunomodulatory effect on the proliferation and apoptosis of allogeneic lymphocytes. These data suggest that the differentiated and undifferentiated allogeneic MSC derived from umbilical cord blood can be a useful candidate for allogeneic cell therapy and transplantation without a major risk of rejection.


Subject(s)
Cell Differentiation , Cell Proliferation , Fetal Blood/cytology , Mesenchymal Stem Cell Transplantation/veterinary , Mesenchymal Stem Cells/immunology , Animals , Cells, Cultured , Flow Cytometry , HLA Antigens/genetics , HLA Antigens/metabolism , Humans , Mesenchymal Stem Cells/cytology , Mice
17.
J Vet Med Sci ; 78(4): 697-700, 2016 May 03.
Article in English | MEDLINE | ID: mdl-26668166

ABSTRACT

A 16-month-old intact female Maltese dog was referred for examination of depression and vomiting. Ultrasonography revealed dilated right renal pelvis containing echogenic fluid with free gas. A hyperechoic material suspected of urolith was identified in the right ureter. Computed tomography revealed emphysematous change of the right kidney associated with ureteral obstruction and extrahepatic portosystemic shunt (EHPSS). Ureteronephrectomy and surgical correction were performed for the EHPSS. Escherichia coli was isolated from pus from the right kidney. Quantitative analysis revealed that the urolith was an ammonium urate stone. After 5 months follow-up, no complication was observed. This is the first report of emphysematous pyonephrosis associated with EHPSS in a dog.


Subject(s)
Dog Diseases/etiology , Emphysema/veterinary , Pyonephrosis/veterinary , Vascular Fistula/veterinary , Animals , Dogs , Emphysema/etiology , Female , Kidney/abnormalities , Liver/abnormalities , Pyonephrosis/etiology , Ureteral Obstruction/complications , Ureteral Obstruction/veterinary , Vascular Fistula/complications , Veins/abnormalities , Vena Cava, Inferior/abnormalities
18.
Differentiation ; 90(1-3): 48-58, 2015.
Article in English | MEDLINE | ID: mdl-26493125

ABSTRACT

In our previous study, dental follicle tissues from extracted wisdom teeth were successfully cryopreserved for use as a source of stem cells. The goals of the present study were to investigate the immunomodulatory properties of stem cells from fresh and cryopreserved dental follicles (fDFCs and cDFCs, respectively) and to analyze in vivo osteogenesis after transplantation of these DFCs into experimental animals. Third passage fDFCs and cDFCs showed similar expression levels of interferon-γ receptor (CD119) and major histocompatibility complex class I and II (MHC I and MHC II, respectively), with high levels of CD119 and MHC I and nearly no expression of MHC II. Both fresh and cryopreserved human DFCs (hDFCs) were in vivo transplanted along with a demineralized bone matrix scaffold into mandibular defects in miniature pigs and subcutaneous tissues of mice. Radiological and histological evaluations of in vivo osteogenesis in hDFC-transplanted sites revealed significantly enhanced new bone formation activities compared with those in scaffold-only implanted control sites. Interestingly, at 8 weeks post-hDFC transplantation, the newly generated bones were overgrown compared to the original size of the mandibular defects, and strong expression of osteocalcin and vascular endothelial growth factor were detected in the hDFCs-transplanted tissues of both animals. Immunohistochemical analysis of CD3, CD4, and CD8 in the ectopic bone formation sites of mice showed significantly decreased CD4 expression in DFCs-implanted tissues compared with those in control sites. These findings indicate that hDFCs possess immunomodulatory properties that involved inhibition of the adaptive immune response mediated by CD4 and MHC II, which highlights the usefulness of hDFCs in tissue engineering. In particular, long-term preserved dental follicles could serve as an excellent autologous or allogenic stem cell source for bone tissue regeneration as well as a valuable therapeutic agent for immune diseases.


Subject(s)
Bone Regeneration , Dental Sac/cytology , Dental Sac/immunology , Immunomodulation , Osteogenesis , Stem Cells/cytology , Stem Cells/immunology , Adaptive Immunity , Animals , CD4 Antigens/immunology , CD4 Antigens/metabolism , Cell Proliferation , Cryopreservation , Dental Sac/transplantation , Genes, MHC Class II/immunology , Humans , Male , Mandible/surgery , Mice , Stem Cell Transplantation , Swine , Swine, Miniature , Tissue Engineering , Tissue Scaffolds
19.
J Vet Sci ; 16(1): 75-85, 2015.
Article in English | MEDLINE | ID: mdl-25269716

ABSTRACT

The purpose of this study was to identify time-related changes in clinical, MRI, histopathologic, and immunohistochemical findings associated with ischemic stroke in dogs. Additionally, the association of cerebrospinal fluid (CSF) and tissue levels of interleukin (IL)-6 with clinical prognosis was assessed. Ischemic stroke was induced by permanent middle cerebral artery occlusion (MCAO) in nine healthy experimental dogs. The dogs were divided into three groups according to survival time and duration of the experimental period: group A (survived only 1 day), group B (1-week experimental period), and group C (2-week experimental period). Neurologic status was evaluated daily. Magnetic resonance imaging (MRI) was performed according to a predetermined schedule. Concentration of IL-6 in CSF was measured serially after ischemic stroke. Postmortem examination was performed for all experimental dogs. During histopathological examination, variable degrees of cavitation and necrosis due to neuronal cytopathic effects, such as pyknotic nuclei and cytoplasmic shrinkage, were observed on the affected side of the cerebral cortex in all dogs. Immunohistochemistry specific for IL-6 showed increased expression in the ischemic lesions. CSF IL-6 concentrations and ischemic lesion volumes 1 day after ischemic stroke were significantly higher in group A compared to groups B and C.


Subject(s)
Brain Ischemia/etiology , Immunohistochemistry , Infarction, Middle Cerebral Artery , Magnetic Resonance Imaging , Stroke/pathology , Animals , Dogs , Female , Male
20.
J Vet Sci ; 16(2): 203-11, 2015.
Article in English | MEDLINE | ID: mdl-25269720

ABSTRACT

In the present study, the use of dogs with experimental autoimmune encephalomyelitis (EAE) as a disease model for necrotizing encephalitis (NE) was assessed. Twelve healthy dogs were included in this study. Canine forebrain tissues (8 g), including white and grey matter, were homogenized with 4 mL of phosphate-buffered saline for 5 min in an ice bath. The suspension was emulsified with the same volume of Freund's complete adjuvant containing 1 mg/mL of killed Mycobacterium tuberculosis H37Ra. Under sedation, each dog was injected subcutaneously with canine brain homogenate at four sites: two in the inguinal and two in the axillary regions. A second injection (booster) was administered to all the dogs using the same procedure 7 days after the first injection. Clinical assessment, magnetic resonance imaging, cerebrospinal fluid analyses, necropsies, and histopathological and immunohistochemical examinations were performed for the dogs with EAE. Out of the 12 animals, seven (58%) developed clinically manifest EAE at various times after immunization. Characteristics of canine EAE models were very similar to canine NE, suggesting that canine EAE can be a disease model for NE in dogs.


Subject(s)
Brain/pathology , Dog Diseases/immunology , Encephalitis/veterinary , Encephalomyelitis, Autoimmune, Experimental/veterinary , Necrosis/veterinary , Animals , Disease Models, Animal , Dogs , Encephalitis/immunology , Encephalomyelitis, Autoimmune, Experimental/immunology , Female , Fluorescent Antibody Technique/veterinary , Immunization/veterinary , Immunohistochemistry/veterinary , Magnetic Resonance Imaging/veterinary , Male , Necrosis/immunology
SELECTION OF CITATIONS
SEARCH DETAIL
...