Background: Bone tissue repair remains a challenge in tissue engineering. Currently, new
materials are being applied and often integrated with live cells and
biological scaffolds. The fibrin biopolymer (FBP) proposed in this study has
hemostatic, sealant, adhesive, scaffolding and drug-delivery properties. The
regenerative potential of an association of FBP, biphasic calcium phosphate
(BCP) and mesenchymal stem cells (MSCs) was evaluated in defects of rat
femurs.Methods: Adult male Wistar rats were submitted to a 5-mm defect in the femur. This
was filled with the following materials and/or associations: BPC; FBP and
BCP; FBP and MSCs; and BCP, FBP and MSCs. Bone defect without filling was
defined as the control group. Thirty and sixty days after the procedure,
animals were euthanatized and subjected to computed tomography, scanning
electron microscopy and qualitative and quantitative histological
analysis.Results:It was shown that FBP is a suitable scaffold for bone defects due to the
formation of a stable clot that facilitates the handling and optimizes the
surgical procedures, allowing also cell adhesion and proliferation. The
association between the materials was biocompatible. Progressive deposition
of bone matrix was higher in the group treated with FBP and MSCs.
Differentiation of mesenchymal stem cells into osteogenic lineage was not
necessary to stimulate bone formation.Conclusions:FBP proved to be an excellent scaffold candidate for bone repair therapies
due to application ease and biocompatibility with synthetic calcium-based
materials. The satisfactory results obtained by the association of FBP with
MSCs may provide a more effective and less costly new approach for bone
tissue engineering.
BackgroundAccurate early diagnosis of lung metastases is important for establishing therapeutic measures. Therefore, the present study aimed to compare survey thoracic radiographs and computerized tomography (CT) scans to specifically identify lung metastases in female dogs with mammary tumors.MethodsTwenty-one female dogs, weighing 3 to 34 kg and aged from 5 years to 14 years and 10 months, with mammary tumors were studied. In all dogs before the imaging examinations, fine-needle aspiration cytology of the mammary tumors was performed to confirm the diagnosis. Three-view thoracic radiographs were accomplished: right lateral, left lateral and ventrodorsal views. Sequential transverse images of the thorax were acquired on a spiral Scanner, before and after intravenous bolus injection of nonionic iodine contrast. Soft-tissue and lung windows were applied. All the mammary tumors were surgically removed and examined histologically.ResultsThe correlation between the cytological and histological results regarding presence of malignancy was observed in only 17 cases. In radiographic examinations, no dog displayed signs of lung metastases or thorax chest lesions. CT detected lung metastasis in two cases, while small areas of lung atelectasis located peripherally were found in 28.57% of the dogs.ConclusionIn this study population, spiral CT showed higher sensitivity than chest radiographies to detect lung metastasis; this indicates that CT should be performed on all female dogs with malignant mammary tumors.
BackgroundThis study aimed to evaluate dogs with pelvic fractures and treated conservatively during locomotion on a pressure-sensing walkway. The hypothesis was that dogs may present changes in kinetic and temporospatial parameters because of the fractures, which may interfere with the symmetry index. Thirty dogs were selected and divided into two groups: Group 1—healthy group (n = 15) and Group 2—conservatively treated group (n = 15). The dogs were of similar body size. The body weight distribution percentages and symmetry indices of the peak vertical force, vertical impulse, stance time, swing time, percentage of stance time, and percentage of swing time of the hind limbs were evaluated.ResultsIn Group 2, the time interval between fracture occurrence and patient evaluation was between 4 and 87 months (mean of 20 months). Four dogs had lower percentage of body weight distribution on one of the hind limbs while three dogs had greater weight distributed toward both hind limbs. Four of these dogs had alterations in the temporospatial and/or kinetic symmetry indices.ConclusionsDogs with pelvic fractures treated conservatively may present changes in percentage of body weight distribution and symmetry indices of the kinetic and temporospatial parameters. The conservative treatment can cause persistent abnormal gait.
The data may be used in future studies comparing the paca to other rodent species. In addition, the paca could be used as an animal model in orthopaedic research.
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