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The anatomical variations of the maxillary septum and the septal bullae can generate challenges during the interpretation of radiographs of the horses' heads and make it difficult to accurately identify the sites affected in sinus disorders. The description of the radiographic appearance of these structures is currently scarce in the scientific literature. This work aims to describe the anatomical and radiographic characteristics of the maxillary septum and maxillary septal bullae in horses. Six chemically preserved equine cadaver heads were used which, after being submitted to the maxillary osseous flap, the maxillary septum and its respective bullae were identified. Radiographic examinations before and after contrast impregnation on these structures were performed. The positioning of the maxillary septum varied between the anatomical specimens and between the sides of the same specimen. The 30° oblique dorsoventral lateral and lateral projections allowed the identification of the maxillary septum and septal bullae. However, the bullae remained superimposed on the dental arches in the dorsoventral projections with the mandible in a neutral position or with the mandible displaced. The oblique offset radiographic positioning was suggested and proved effective for the examination of the maxillary septal bullae, where the mandible was displaced to the side of the bullae to be examined, and the radiographic beam inclined in the same direction. The maxillary septum and its bullae could be properly identified in a macroscopic way after the osseous flap and the contrasted radiographic examination allowed its adequate interpretation. Variations in size and position are considered normal for the equine species.

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BACKGROUND: Preservation of biological tissues has been used since ancient times. Regardless of the method employed, tissue preservation is thought to be a vital step in veterinary surgery teaching and learning. OBJECTIVES: This study was designed to determine the usability of chemically preserved cadaveric equine heads for surgical teaching in veterinary medicine. METHODS: Six cadaveric equine heads were collected immediately after death or euthanasia and frozen until fixation. Fixation was achieved by using a hypertonic solution consisting of sodium chloride, sodium nitrite and sodium nitrate, and an alcoholic solution containing ethanol and glycerin. Chemically preserved specimens were stored at low temperatures (2°C to 6°C) in a conventional refrigerator. The specimens were submitted to gross and organoleptic assessment right after fixative solution injection (D0) and within 10, 20, and 30 days of fixation (D10, D20, and D30, respectively). Samples of tissue from skin, tongue, oral vestibule, and masseter muscle were collected for histological evaluation at the same time points. RESULTS: Physical and organoleptic assessments revealed excellent specimen quality (mean scores higher than 4 on a 5-point scale) in most cases. In some specimens, lower scores (3) were assigned to the range of mouth opening, particularly on D0 and D10. A reduced the range of mouth opening may be a limiting factor in teaching activities involving structures located in the oral cavity. CONCLUSIONS: The excellent physical, histologic, and organoleptic characteristics of the specimens in this sample support their usability in teaching within the time frame considered. Appropriate physical and organoleptic characteristics (color, texture, odor, and flexibility) of the specimens in this study support the use of the method described for preparation of reusable anatomical specimens.

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Mast cell tumours (MCTs) are the most frequent malignant skin neoplasm in dogs. Due to the difficulty in purifying large numbers of canine neoplastic mast cells, relatively little is known about their properties. A reproducible in vitro model is needed to increase the understanding about the phenotype and functional properties of neoplastic mast cells. In the present study, we describe the establishment of primary cocultures of neoplastic mast cells from canine cutaneous MCTs and cancer-associated fibroblasts. We confirmed the inability of canine neoplastic mast cells to remain viable for long periods in vitro without the addition of growth factors or in vivo passages in mice. Using a transwell system, we observed that mast cell viability was significantly higher when there is cell-to-cell contact in comparison to non-physical contact conditions and that mast cell viability was significantly higher in high-grade than in low-grade derived primary cultures. Moreover, the use of conditioned medium from co-cultured cells led to a significantly higher tumoral mast cell viability when in monoculture. Signalling mechanisms involved in these interactions might be attractive therapeutic targets to block canine MCT progression and deserve more in-depth investigations.

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INTRODUCTION: Intervertebral disc diseases (IVDD) represent the majority of neurological attendance and responsible for the most cases of paralysis in dogs. Treatments currently used do not show satisfactory results in patients with more severe and chronic neurological manifestations. METHODS: To promote nerve and muscular recovery, as well as improve quality of life, we aimed to create a double-blind test method, associating spinal decompression surgery and allogeneic transplantation of amniotic membrane-derived stem cells (AMSCs) in dogs with chronic IVDD. Cells were characterized as fetal mesenchymal cells and safe for application. Eight animals completed the experiment: stem cell applications were made in four animals that had previously undergone an unsuccessful surgical procedure ("SC group", n = 4); two animals were submitted to surgery, followed by applications of stem cells ("Surgery + SC", n = 2); two other animals were submitted to surgery, followed by the application of saline solution ("Surgery + placebo", n = 2). During the surgical procedure, a topical application was performed on the lesion and after fifteen and forty-five days another two applications were made via epidural. Animals were monitored biweekly and reassessed three months after surgery, by functional tests and magnetic resonance exams. RESULTS: Some animals presented significant neurological improvement, such as the recovery of nociception and ability to remain on station. Despite the need further studies, until the present moment, cell therapy has been feasible and has no harmful effects on animals. CONCLUSION: The protocol of preclinical trial showed the association with decompressive surgery and cell transplantation in dogs with thoracolumbar IVDD proved feasible, and it was possible to observe neurological improvement after treatment. No tissue improvement through MRI was found. The double-blind test guaranteed reliability of the evaluations and results obtained that, even with a small sample size, generated satisfactory results for the animals and owners.

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BACKGROUND: For horses requiring prolonged daily cephalic intravenous regional limb perfusion (IVRLP), the use of a totally implantable catheter (TIC) could be indicated to reduce complications associated with frequent venipuncture or external catheterization. This study aims to evaluate the implantation technique of the TIC in the cephalic vein of horses for IVRLP, describe the complications associated with the device's placement and use, and assess its viability up to 60 days after implantation. Totally implantable catheters, cut to 15 cm (n = 5) and 46 cm (n = 5) in length, were implanted into one cephalic vein in ten adult horses (n = 10). Twenty-four hours following placement, IVRLP with contrast was performed via the TIC and evaluated with radiography. Physical examinations, lameness evaluation, hematologic assessment, and the catheter patency tests were performed at scheduled intervals for the duration of catheterization (7-60 days). RESULTS: Catheters were implanted without difficulty and allowed for IVRLP 24 h post implantation. Complications resulted in removal of the catheters, with four maintained for 7 days, three in place for 15 days, and three catheters maintained for 60 days. Complications included lameness, limb swelling, catheter kinking, and venous thrombosis. CONCLUSIONS: The implantation technique of the TIC in the cephalic vein of horses is feasible and requires minimal technical effort. Although TIC allows venous access without the need for repeated venipuncture, its long-term use presents complications. For horses requiring prolonged daily cephalic IVRLP, the use of a TIC could be indicated. However, the high incidence of venous thrombosis may limit clinical application.

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PURPOSE: To analyze and compare the reactions at the interface between the composite, composed of fragmented heterologous mineralized bone matrix (MOMHF) and polymethylmethacrylate (PMMA), and the rabbit's tibias, through macroscopic evaluation and scanning electron microscopy (SEM) in different periods. METHODS: In this study, 12 New Zealand adult rabbits were used (E1: n = 3, E2: n = 3, E3: n = 3 and E4: n = 3). They had the right tibial defects filled with composite and were evaluated immediately after surgery and at 30, 60, 90, and 120 days. RESULTS: The composites were incorporated and integrated into the recipient beds in 100% of the cases, defined by the MOMHF osseointegration and the PMMA fibrointegration, with no sign of infection, migration, or rejection. CONCLUSIONS: The behavior of the composites in the recipient beds demonstrates that these biomaterials have the potential to be used in bone defect repairs, offering, thus, better quality of life to the orthopedic patient.

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The use of live animals for educational purposes is an old practice that is still employed in teaching and research institutions. However, there are several objections to this practice, whether for ethical or humanitarian reasons. Surgical techniques teaching using anatomical pieces and/or preserved cadavers promotes greater learning efficiency, provides exercise repetition and increases the confidence and satisfaction of the students when compared to the use of live animals. The current work aimed to analyse the feasibility of using fresh swine urinary bladder and small intestines (jejunum), obtained from slaughterhouses, fixed in 99.8% ethyl alcohol (EA) and preserved in sodium chloride hypersaturated solution (SCHS) at 30%, for 7, 14 and 21 days, as an alternative method for surgical skills training (SST). Swine viscera, fixed in EA and preserved in SCHS, presented a realistic appearance, absence of odour and maintained the viable morphological characteristics during the performance of the operative techniques. Preservation solutions had low cost, were easy to acquire and did not offers risks to human health. Therefore, urinary bladders and small intestines fixed in 99.8% EA for 30 days and maintained in 30% SCHS at different periods were demonstrated as a good viable option as a preservation method for surgical skills training.

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ABSTRACT Purpose To analyze and compare the reactions at the interface between the composite, composed of fragmented heterologous mineralized bone matrix (MOMHF) and polymethylmethacrylate (PMMA), and the rabbit's tibias, through macroscopic evaluation and scanning electron microscopy (SEM) in different periods. Methods In this study, 12 New Zealand adult rabbits were used (E1: n = 3, E2: n = 3, E3: n = 3 and E4: n = 3). They had the right tibial defects filled with composite and were evaluated immediately after surgery and at 30, 60, 90, and 120 days. Results The composites were incorporated and integrated into the recipient beds in 100% of the cases, defined by the MOMHF osseointegration and the PMMA fibrointegration, with no sign of infection, migration, or rejection. Conclusions The behavior of the composites in the recipient beds demonstrates that these biomaterials have the potential to be used in bone defect repairs, offering, thus, better quality of life to the orthopedic patient.

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Apresenta-se um modelo experimental de ostectomia de tíbia em coelhos para estudo de biomateriais em processos de reparação óssea. Foi realizada falha segmentar de 6mm de diâmetro na região metafisária medial proximal de tíbia de 72 coelhos as quais foram preenchidas com substituto ósseo e avaliadas clinicamente, por exame radiográfico e por meio de tomografia computadorizada feixe cônico, em diferentes tempos. Conclui-se que a metáfise medial proximal de tíbia de coelhos é adequada como modelo para estudos que avaliem o comportamento de enxertos e/ou biomateriais em falhas ósseas.

Is presented an experimental model of tibial ostectomy in rabbits to study biomaterials during bone repair process. Segmental failure of 6 mm diameter was performed in the medial proximal tibial metaphyseal region of 72 rabbits, which were filled with bone substitute and evaluated by clinical exam, X-ray, and cone beam computed tomography at different times. It is concluded that the medial proximal tibial metaphysis region of rabbits is suitable as a model for studies that evaluate the behavior of grafts and/or biomaterials on bone defects.

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Apresenta-se um modelo experimental de ostectomia de tíbia em coelhos para estudo de biomateriais em processos de reparação óssea. Foi realizada falha segmentar de 6mm de diâmetro na região metafisária medial proximal de tíbia de 72 coelhos as quais foram preenchidas com substituto ósseo e avaliadas clinicamente, por exame radiográfico e por meio de tomografia computadorizada feixe cônico, em diferentes tempos. Conclui-se que a metáfise medial proximal de tíbia de coelhos é adequada como modelo para estudos que avaliem o comportamento de enxertos e/ou biomateriais em falhas ósseas.

Is presented an experimental model of tibial ostectomy in rabbits to study biomaterials during bone repair process. Segmental failure of 6 mm diameter was performed in the medial proximal tibial metaphyseal region of 72 rabbits, which were filled with bone substitute and evaluated by clinical exam, X-ray, and cone beam computed tomography at different times. It is concluded that the medial proximal tibial metaphysis region of rabbits is suitable as a model for studies that evaluate the behavior of grafts and/or biomaterials on bone defects.

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