safranine-t and Disease-Models--Animal

The aim of this study was to investigate the effect of high fat diet and excessive compressive mechanical force on temporomandibular joint. In vivo, a mouse model of temporomandibular joint compressive loading device was used. A high fat diet mouse model and a combined mouse model intraperitoneally treated with or without simvastatin were used in the study. The pathological changes of mandibular condylar cartilage were assessed by Safranin-O staining. The IL-1β, MMP-3, leptin expression changes in the cartilage were detected by immunohistochemistry. In vitro, the mandibular condylar chondrocytes were treated with or without L-1β and simvastatin. The mRNA expression level of matrix MMPs and leptin were assessed. Both excessive compressive mechanical force and high fat diet induced obesity caused TMJ osteoarthritis-like changes and increased expression of IL-1β, MMP-3, and leptin. These pathological changes were much more serious when the two interventions were exerted together, while simvastatin could obviously alleviate these changes. The mRNA expression of MMP-3, MMP-13, and leptin increased in the IL-1β treated chondrocytes treated with IL-1β, and decreased with simvastatin treatment. The development of temporomandibular joint pathological changes could be caused by the excessive compressive mechanical force and high fat diet induced obesity.

Topics: Animals; Chondrocytes; Diet, High-Fat; Disease Models, Animal; Interleukin-1beta; Leptin; Male; Mandible; Matrix Metalloproteinase 3; Mice; Mice, Inbred C57BL; Obesity; Phenazines; Risk Factors; Simvastatin; Stress, Mechanical; Temporomandibular Joint

Juvenile idiopathic arthritis (JIA) of the temporomandibular joint (TMJ) can cause severe growth disturbances of the craniomandibular system. Antigen-induced arthritis (AIA) of the rabbit TMJ is simulating the inflammatory process of the TMJ in JIA. The aim of this study was to investigate the effect of a systemic administration of the tumor necrosis factor-alpha (TNF-α) antagonist etanercept on AIA in rabbits by means of three different histological staining methods.. After sensitization, a bilateral arthritis of the TMJ was induced and maintained by repeated intra-articular administrations of ovalbumin in 12 New Zealand white rabbits aged 10 weeks. From the 13th week of age, 6 of the 12 rabbits received weekly subcutaneous injections of etanercept, and the other 6 animals remained without therapy. Another 6 animals served as controls, receiving no treatment or intra-articular injections at all. After euthanasia at the age of 22 weeks, all TMJs were retrieved en bloc. Sagittal sections were cut and stained with hematoxylin-eosin (H-E), Safranin-O for the evaluation of the Mankin score, and tartrate-resistant acid phosphatase (TRAP).. In the arthritis group, a chronic inflammation with degeneration of the articular cartilage was visible. In the etanercept group, the signs of cartilage degeneration were significantly reduced but present. In contrast, the joints in the control group were inconspicuous. A strong correlation between the Mankin score and TRAP-positive cells could be found.. Antigen-induced arthritis causes severe damage in the TMJ of young rabbits. An improvement seems to be achievable by a systemic administration of etanercept.

Topics: Acid Phosphatase; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Experimental; Arthritis, Juvenile; Biomarkers; Cartilage, Articular; Coloring Agents; Disease Models, Animal; Etanercept; Female; Freund's Adjuvant; Injections, Intra-Articular; Injections, Subcutaneous; Isoenzymes; Mandibular Condyle; Osteoclasts; Ovalbumin; Phenazines; Rabbits; Random Allocation; Tartrate-Resistant Acid Phosphatase; Temporomandibular Joint Disorders; Time Factors

Multifunctional granular mast cells (MCs) are among targets in bronchial asthma (BA) therapy. We studied pulmonary MC population in a rat model of BA under the effect of β-adrenoreceptor antagonists and of the latter combined with the standard therapy (glucocorticoid budesonide + β2-adrenergic agonist salbutamol). MCs of different degrees of maturity were identified on paraffin section of lung stained with Alcian blue and Safranin. MC density in the lung of rats with BA increased 1.9 times. Alcian blue-positive immature cells predominated in the lungs of both intact rats and rats with BA. In response to pharmacological agents, the mean MC densities were reduced in 2-2.7 times in all the variants of experiments and were close to the norm. It allows us to suppose that MCs migration from the outside was suppressed and, in consequence of the decline of MC densities, the release of the mediators involved in the progression of BA may be diminished.

Topics: Adrenergic beta-Agonists; Adrenergic beta-Antagonists; Albuterol; Alcian Blue; Animals; Anti-Asthmatic Agents; Asthma; Bisoprolol; Budesonide; Cell Count; Disease Models, Animal; Drug Therapy, Combination; Glucocorticoids; Lung; Male; Mast Cells; Metoprolol; Phenazines; Rats; Receptors, Adrenergic, beta

Transforming growth factor-beta (TGF-β) plays an important part in the repair of cartilage in osteoarthritis. It has been hypothesised that intra-articular injection of TGF-β₁ promotes repair of cartilage and protects the subchondral bone from damage in osteoarthritic temporomandibular joints (TMJs). We made bilateral partial perforations of the disc to induce osteoarthritic joints in 36 rabbits. TGF-β₁ 20, 40, or 80 ng were injected into the right joint, and vehicle alone was injected into the left joint. Four additional animals were used as normal controls. Microcomputed tomography was used to quantify the three-dimensional microarchitecture of subchondral bone, followed by assessment of the proteoglycan content. All joints treated with TGF-β₁ were covered by a layer of well-organised fibrocartilage, and had increased proteoglycan content and normal microarchitectural properties, whereas the joint treated by vehicle alone had typical osteoarthritis-related degradation of cartilage and sclerosis of subchondral bone. These results suggested that TGF-β₁ is an effective way of treating osteoarthritis of the TMJ.

Topics: Animals; Bone Density; Calcification, Physiologic; Cartilage, Articular; Chondrocytes; Coloring Agents; Disease Models, Animal; Fibrocartilage; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Injections, Intra-Articular; Male; Mandibular Condyle; Osteoarthritis; Phenazines; Proteoglycans; Rabbits; Random Allocation; Sclerosis; Temporomandibular Joint Disc; Temporomandibular Joint Disorders; Transforming Growth Factor beta1; X-Ray Microtomography

The purpose of this study was to investigate the underlying mechanism in favorable prognosis following pediatric condylar fractures managed by closed procedures. Seventy-five 1-month-old male Wistar rats were used in this experiment. Unilateral medially rotated condyle fracture in growing rats was adopted as the condyle fracture model to investigate the mechanism in favorable healing of pediatric condylar fractures. The entire fracture healing process was investigated. The rotated subcondylar fractures in young rats healed by means of callus formation, with simultaneous and prompt repositioning of the condyle. The positive outcome in these condyle fractures was also associated with active cell proliferation potential in the condyle, as well as the condyle's remodeling capability. The growth potential and remodeling capability of the condyle during the growing period might be the intrinsic factor for favorable healing following pediatric condylar fractures managed by closed procedures.

Topics: Acid Phosphatase; Animals; Azo Compounds; Biomarkers; Body Weight; Bone Remodeling; Bony Callus; Cartilage, Articular; Cell Proliferation; Chondrocytes; Coloring Agents; Disease Models, Animal; Eosine Yellowish-(YS); Fracture Healing; Isoenzymes; Joint Dislocations; Male; Mandibular Condyle; Mandibular Fractures; Methyl Green; Osteogenesis; Phenazines; Prognosis; Proliferating Cell Nuclear Antigen; Random Allocation; Rats; Rats, Wistar; Tartrate-Resistant Acid Phosphatase; Treatment Outcome

Tissue inhibitor of metalloproteinases-3 (TIMP-3) is known to inhibit matrix metalloproteinases, aggrecanases, and tumor necrosis factor (TNF)-alpha-converting enzyme (TACE, ADAM17). These metalloproteases participate in different aspects of joint destruction in inflammatory arthritis. To determine the relative importance of this inhibitor in joint pathology, wild-type and Timp3-/- mice were immunized with methylated bovine serum albumin followed by arthritis induction by intra-articular injection of the same antigen. Animals were monitored for up to 14 days after challenge, and joint tissues were analyzed by routine and Safranin O staining and for the presence of aggrecan neoepitopes produced by metalloprotease cleavage. Serum TNF-alpha was measured by immunoassay. Compared to wild-type animals, Timp3-/- mice showed a dramatic increase in the initial inflammatory response to intra-articular antigen injection, and serum TNF-alpha levels were greatly elevated in the Timp3-/- animals after immunization. However, these differences in clinical features disappeared by days 7 to 14. No difference in Safranin O staining or aggrecan cleavage site neoepitope abundance was seen. Thus, in inflammatory joint disease TIMP-3 likely dampens the inflammatory response of TNF-alpha by reducing ADAM17 activity.

Topics: ADAM Proteins; ADAM17 Protein; Aggrecans; Animals; Antigens; Arthritis; Coloring Agents; Disease Models, Animal; Extracellular Matrix Proteins; Immunohistochemistry; Inflammation; Injections, Intra-Articular; Lectins, C-Type; Metalloendopeptidases; Mice; Mice, Knockout; Phenazines; Proteoglycans; Serum Albumin, Bovine; Tissue Inhibitor of Metalloproteinase-3; Tumor Necrosis Factor-alpha

In this study, hydrogel scaffolds, based on the polymer oligo(poly(ethylene glycol) fumarate) (OPF), were implanted into osteochondral defects in the rabbit model. Scaffolds consisted of two layers-a bottom, bone forming layer and a top, cartilage forming layer. Three scaffold formulations were implanted to assess how material composition and transforming growth factor-beta1 (TGF-beta1) loading affected osteochondral repair. Critical histological evaluation and scoring of the quantity and quality of tissue in the chondral and subchondral regions of defects was performed at 4 and 14 weeks. At both time points, no evidence of prolonged inflammation was observed, and healthy tissue was seen to infiltrate the defect area. The quality of this tissue improved over time with hyaline cartilage filling the chondral region and a mixture of trabecular and compact bone filling the subchondral region at 14 weeks. A promising degree of Safranin O staining and chondrocyte organization was observed in the newly formed surface tissue, while the underlying subchondral bone was completely integrated with the surrounding bone at 14 weeks. Material composition within the bottom, bone-forming layer did not appear to affect the rate of scaffold degradation or tissue filling. However, no bone upgrowth into the chondral region was observed with any scaffold formulation. TGF-beta1 loading in the top layer of scaffolds appeared to exert some therapeutic affect on tissue quality, but further studies are necessary for scaffold optimization. Yet, the excellent tissue filling and integration resulting from osteochondral implantation of these OPF-based scaffolds demonstrates their potential in cartilage repair strategies.

Topics: Absorbable Implants; Animals; Biocompatible Materials; Bone and Bones; Bone Diseases; Bone Substitutes; Cartilage; Cartilage, Articular; Chondrocytes; Coloring Agents; Disease Models, Animal; Fractures, Bone; Gelatin; Hydrogel, Polyethylene Glycol Dimethacrylate; Hydrogels; Inflammation; Lipid Bilayers; Materials Testing; Osteochondritis; Phenazines; Polyesters; Polyethylene Glycols; Rabbits; Regression Analysis; Time Factors; Tissue Engineering; Transforming Growth Factor beta; Transforming Growth Factor beta1; Wound Healing

Coronal stepoffs of 0.5 mm (equal to the cartilage height) were created on the medial femoral condyles of adult, skeletally mature rabbits as a model for articular surface incongruity. After 3, 6, 12, and 24 weeks, tissue was analyzed histologically using hematoxylin and eosin and Safranin O staining, autoradiographs were made of the femoral condyles, and immunohistologic analysis was done for 3-B-3(-) and 7-D-4 chondroitin sulfate epitopes. An overlapping flap from the high toward the low side and an increase of the cartilage height on the low side of the defect were observed as permanent features of adaptation throughout the entire followup. Significant degeneration was not seen around the lesion or in the tibial cartilage opposing a stepoff defect. Autoradiography showed a three-phase response to the lesion: an early increase in radiolabeled sulfate (35SO4) uptake, a sharp decline of 35SO4 uptake, and finally a late recovery of the autoradiographic signal indicating partial recovery of proteoglycan synthetic activity. After an early increase, immunohistologic analysis for 3-B-3(-) showed a subsiding tendency by 24 weeks, and the staining with 7-D-4 remained elevated uniformly in the vicinity of the lesion. A rabbit femoral stepoff defect with an offset of 0.5 mm may remodel and not lead to degeneration within the first 6 months after injury in a stable joint.

Topics: Adaptation, Physiological; Animals; Autoradiography; Cartilage Diseases; Cartilage, Articular; Chondroitin Sulfates; Coloring Agents; Disease Models, Animal; Eosine Yellowish-(YS); Epitopes; Female; Femur Head; Fluorescent Dyes; Follow-Up Studies; Hematoxylin; Hindlimb; Immunohistochemistry; Phenazines; Proteoglycans; Rabbits; Radiopharmaceuticals; Range of Motion, Articular; Sulfates; Sulfur Radioisotopes

A slowly progressive osteoarthritis model in the skeletally immature canine knee joint is described. Forty-four young female beagle dogs were chosen as experimental animals. In 15 dogs, a 30 degrees valgus angulation of the right tibia was created by operation. Fourteen dogs underwent sham operation. Fifteen dogs served as control subjects. Alterations in the knee joints were evaluated macroscopically and histologically 7 and 18 months after operation. Seven months after surgery, two of seven beagles that had valgus osteotomy had a lesion with discoloration of cartilage in the medial condyle of the femur. Eighteen months after operation, five of the eight dogs that had valgus osteotomy showed fibrillation of the femoral and tibial cartilages. Mankin's scoring of the knee joint cartilages indicated statistically significant changes as compared with control subjects 7 and 18 months after surgery. Biomechanical analysis revealed shift of the mechanical axis toward the lateral compartment of the knee by the valgus osteotomy, patellofemoral malalignment, and inclination of the tibiofemoral joint line. These biomechanical alterations brought about the most severe cartilage lesions to the medial condyle of the femur and the patellofemoral joint. Cartilage fibrillation took more than 7 months to develop. Thus, this model offers a slowly progressive, well standardized, and reproducible method for the study of early changes of osteoarthritis in young beagle dogs.

Topics: Animals; Biomechanical Phenomena; Cartilage, Articular; Chondrocytes; Coloring Agents; Disease Models, Animal; Disease Progression; Dogs; Female; Femur; Follow-Up Studies; Hindlimb; Menisci, Tibial; Osteoarthritis; Osteotomy; Patella; Phenazines; Reproducibility of Results; Tibia

A method of image analysis has been developed for use in the semiquantitative histomorphometric assessment of glycosaminoglycans in articular cartilage stained with safranin O. The reliability of the methodology is reported along with its application to the assessment of articular cartilage in a model of osteoarthritis, i.e., transection of the anterior cruciate ligament in rabbits. With this system, specimens of normal and osteoarthritic articular cartilage were assessed histomorphometrically for the following parameters: total cartilage area, percentage of safranin O stained area, mean gray scale (average stain intensity), and gray scale index (the relative total amount of glycosaminoglycans). Reproducibility was established for 12 specimens of normal cartilage and found to have a SD of less than 8% of the mean for each parameter that was measured. Image analysis of osteoarthritic cartilage revealed each of the parameters, except for average stain intensity, to be significantly lower than that in control cartilage.

Topics: Animals; Cartilage, Articular; Disease Models, Animal; Femur Head; Glycosaminoglycans; Image Processing, Computer-Assisted; Indicators and Reagents; Knee Joint; Osteoarthritis; Phenazines; Rabbits; Reproducibility of Results

Children with juvenile rheumatoid arthritis or juvenile chronic arthritis often exhibit temporomandibular joint (TMJ) involvement accompanied by pain, dysfunction, and growth abnormalities. Despite the severe functional and developmental consequences of this disease, its pathogenesis remains poorly understood, but important insights may be provided by a suitable animal model of this disease. The purpose of this study was to develop and histologically characterize a juvenile animal model of antigen-induced arthritis of the TMJ. Arthritis was induced with an intra-articular administration of ovalbumin in previously sensitized 10-week-old male New Zealand white rabbits. Sham-treated and untreated rabbits were used as controls. The TMJs were retrieved en bloc at 5, 10, 15, 35, and 55 days post-challenge for histology and matrix histochemistry. Antigen-treated joints demonstrated severe arthritis, including mononuclear cell infiltration, synovial lining and villous hyperplasia, and pannus formation, as early as 5 days after challenge; the arthritis was maintained up to 55 days post-challenge. A decrease in the area of the TMJ disc that stained positively for glycosaminoglycans was observed throughout the experimental period. Loss of collagen staining was primarily localized to sites at the junction of the synovium with bone and fibrocartilage. The histopathologic features of this model of antigen-induced arthritis of the juvenile rabbit TMJ are similar to those observed previously in adult animal models of experimental arthritis and in human rheumatoid arthritis. This animal model will be useful for understanding the pathogenesis of juvenile rheumatoid arthritis of the TMJ, and for exploring the mechanisms for aberrant craniofacial growth.

Topics: Analysis of Variance; Animals; Arthritis, Experimental; Arthritis, Juvenile; Cartilage, Articular; Collagen; Coloring Agents; Disease Models, Animal; Extracellular Matrix Proteins; Glycosaminoglycans; Histocytochemistry; Male; Ovalbumin; Phenazines; Rabbits; Synovial Membrane; Synovitis; Temporomandibular Joint Disorders

Microbiochemical assays of the proteoglycan and collagen content of articular cartilage and synovial lining have been performed on tissue sections taken from rabbits with antigen-induced arthritis. This experimental arthritis is a close analogue of the natural disease-rheumatoid arthritis. Animals were killed at intervals during the first 21 days following induction of arthritis to assess changes in the composition of the extracellular matrices of the synovial lining and articular cartilage during the early development of this experimental lesion. In confirmation of earlier studies these microbiochemical assays revealed a rapid and significant loss of proteoglycan from the articular cartilage. This loss was, however, not uniform but was restricted to the intermediate zone of the cartilage. Over the period studied, there was only a slight loss of proteoglycan from the superficial zone of the cartilage facing the joint cavity. These findings demonstrate that, at least in this model, cartilage proteoglycan loss is not due to the action of proteases present in the synovial fluid. Moreover it suggests that the chondrocytes in the mid-zone of the cartilage are responsive to those signals stimulating proteoglycan breakdown. There was no significant loss of collagen from the cartilage over the time period of this study. The synovial lining from arthritic joints, in contrast, showed a progressive increase in both proteoglycan and collagen.

Topics: Animals; Arthritis, Rheumatoid; Azo Compounds; Cartilage, Articular; Collagen; Disease Models, Animal; Femur; Male; Ovalbumin; Phenazines; Picrates; Proteoglycans; Rabbits; Staining and Labeling