Femoral orthopedic implants in dogs with titanium - mechanical evaluation

Background: Orthopedic implants are commonly used for different types of surgical procedures to gain optimal functionand to provide stability to both bones and tendon structures. When inserting these implants, the characteristics of the material are important for surgical success, and the ideal implant must be biocompatible and nonallergenic. However, whenmolding an implant to the bone structure, its resistance can change significantly. Implants can be temporary or permanentin the body, and metal possesses properties that make it acceptable for bone repair. In biomedical implants, 2 types aremost common, commercially pure (CP)-Ti and Ti-6A1-4V. They both provide stable fixation and low risk of loosening.Implants made with the same material and composition can perform differently if the material has been altered by processing techniques for different scenarios. Stress, strain and elastic modulus are the primary metrics used in the description ofimplant materials. They can be calculated based on mechanical tests of specimens with defined geometry, most commonlytensile, bending and torsional tests. In order to better evaluate those changes, we compared the mechanical characteristicsof titanium bone plates, before and after they were molded to the bone, to verify and quantify the loss of stiffness andresistance after molding the plate.Materials, Methods & Results: The study was prospective. Orthopedic implant made of commercially pure titanium (CPTi) were divided into 2 groups, one group without plate molding and the other with plate molding to a dog femora bone.Thirty-six plates of different sizes (5.0, 6.5, 8.0, 9.0, 10.0- and 11.0-mm diameter) were divided into 6 groups containing6 plates of each size and submitted to the 4-point flexion test of resistance, using a piece of dog femur (weights of 5, 10,15, 20 and 25 kg) as the bone in which the...

Femoral orthopedic implants in dogs with titanium - mechanical evaluation

Background: Orthopedic implants are commonly used for different types of surgical procedures to gain optimal functionand to provide stability to both bones and tendon structures. When inserting these implants, the characteristics of the material are important for surgical success, and the ideal implant must be biocompatible and nonallergenic. However, whenmolding an implant to the bone structure, its resistance can change significantly. Implants can be temporary or permanentin the body, and metal possesses properties that make it acceptable for bone repair. In biomedical implants, 2 types aremost common, commercially pure (CP)-Ti and Ti-6A1-4V. They both provide stable fixation and low risk of loosening.Implants made with the same material and composition can perform differently if the material has been altered by processing techniques for different scenarios. Stress, strain and elastic modulus are the primary metrics used in the description ofimplant materials. They can be calculated based on mechanical tests of specimens with defined geometry, most commonlytensile, bending and torsional tests. In order to better evaluate those changes, we compared the mechanical characteristicsof titanium bone plates, before and after they were molded to the bone, to verify and quantify the loss of stiffness andresistance after molding the plate.Materials, Methods & Results: The study was prospective. Orthopedic implant made of commercially pure titanium (CPTi) were divided into 2 groups, one group without plate molding and the other with plate molding to a dog femora bone.Thirty-six plates of different sizes (5.0, 6.5, 8.0, 9.0, 10.0- and 11.0-mm diameter) were divided into 6 groups containing6 plates of each size and submitted to the 4-point flexion test of resistance, using a piece of dog femur (weights of 5, 10,15, 20 and 25 kg) as the bone in which the...(AU)

New technique for intrathoracic implantation of extraluminal spiral prostheses in the trachea

Background: Extraluminal surgical procedures for intrathoracic tracheal collapse in dogs are not routinely performed. The patients are normally treated with different drugs or by intraluminal stents. However, in more severe cases, drug treatment does not always have good outcomes, and intraluminal prostheses can be correlated to several postoperative problems. In order to obtain better results, we aimed to develop a surgical technique for implantation of a new extraluminal helical prosthesis in the thoracic segment of the trachea through cervical access, associated with pneumatic mediastinoscopy for certification of the technique and minimization of possible complications. Materials, Methods & Results: Seven canine corpses (CCs) from non-traumatic death, weighing between 2 and 7 kg, were used. A ventral cervical approach to the trachea was associated with blunt mediastinal dissection. Trans cervical pneumatic mediastinoscopy was used for evaluation of the dissection and location of the implant. These were compared with the necropsy findings by the exact Wilcoxon two-sample test, with P < 0.05. The results of necropsy and mediastinoscopy did not present significant differences at P < 0.05. During the examinations, the presence of some mediastinal visceral le-sions caused by the prosthesis, the integrity of the mediastinum and possible lesions to RLN and blood vessels (BV) were analyzed. We also investigated the location of the distal part of the prosthesis in the thoracic segment of the trachea and its dissection. To evaluate the technique, statistical comparison was made between mediastinoscopy and necropsy find-ings. The data were compared by the Wilcoxon test at 5% probability. The tracheas of all CCs were efficiently dissected, but in some cases problems that can happen during the procedure were noticed. This was checked by mediastinoscopy and confirmed by necropsy. The median of the scores was...

New technique for intrathoracic implantation of extraluminal spiral prostheses in the trachea

Background: Extraluminal surgical procedures for intrathoracic tracheal collapse in dogs are not routinely performed. The patients are normally treated with different drugs or by intraluminal stents. However, in more severe cases, drug treatment does not always have good outcomes, and intraluminal prostheses can be correlated to several postoperative problems. In order to obtain better results, we aimed to develop a surgical technique for implantation of a new extraluminal helical prosthesis in the thoracic segment of the trachea through cervical access, associated with pneumatic mediastinoscopy for certification of the technique and minimization of possible complications. Materials, Methods & Results: Seven canine corpses (CCs) from non-traumatic death, weighing between 2 and 7 kg, were used. A ventral cervical approach to the trachea was associated with blunt mediastinal dissection. Trans cervical pneumatic mediastinoscopy was used for evaluation of the dissection and location of the implant. These were compared with the necropsy findings by the exact Wilcoxon two-sample test, with P < 0.05. The results of necropsy and mediastinoscopy did not present significant differences at P < 0.05. During the examinations, the presence of some mediastinal visceral le-sions caused by the prosthesis, the integrity of the mediastinum and possible lesions to RLN and blood vessels (BV) were analyzed. We also investigated the location of the distal part of the prosthesis in the thoracic segment of the trachea and its dissection. To evaluate the technique, statistical comparison was made between mediastinoscopy and necropsy find-ings. The data were compared by the Wilcoxon test at 5% probability. The tracheas of all CCs were efficiently dissected, but in some cases problems that can happen during the procedure were noticed. This was checked by mediastinoscopy and confirmed by necropsy. The median of the scores was...(AU)

Videothermometry to evaluate metabolic activity in real time during pneumectomy in rats

Purpose:To evaluate, in rats, the open field videothermometry in real time while performing left pneumonectomy for early diagnosis of cardiopulmonary changes.Methods:Twelve non-specific pathogen-free Wistar rats were randomly allocated into two groups; pneumectomy group (GP) and sham surgery group (GS). Mean arterial pressure, videothermometry in real time, of the right lung, and histopathological analysis of the remaining lung were evaluated in all animals.Results:Videothermometry in real time allowed identification of temperature variance of right lung after pneumectomy, indicating a significant decrease in temperature during evaluation. There was a statistical difference between M0 and M1, M1 and M2 and M0 and M2 (p<0.004) in GS, and significant difference between M0 and M1, M1 and M2, and M2 and M0 with p<0.0001 in GP.Conclusions:Left pneumonectomy in rats shows initial histopathological changes after 60 minutes of its completion, indicating a possible compensation beginning. The open-field videothermometry in real time proved to be efficient identifying the temperature changes of the remaining lung.(AU)

Technical innovation: Intragastric Single Port Sleeve Gastrectomy (IGSG). A feasibility survival study on porcine model

Purpose: To perform technically the laparoscopic sleeve gastrectomy (LSG) using a unique Intragastric Single Port (IGSG) in animal swine model, evidencing an effective and safe procedure, optimizing the conventional technique.Methods: IGSG was performed in 4 minipigs, using a percutaneous intragastric single port located in the pre-pyloric region. The gastric stapling of the greater curvature started from the pre-pyloric region towards the angle of His by Endo GIA system and the specimen was removed through the single port. In the postoperative day 30, the animals were sacrificed and submitted to autopsy.Results: All procedures were performed without conversion, and all survived 30 days. The mean operative time was 42 min. During the perioperative period no complications were observed during invagination and stapling. No postoperative complications occurred. Post-mortem examination showed no leaks or infectious complications.Conclusion: Intragastric Single Port is a feasible procedure that may be a suitable alternative technique of sleeve gastrectomy for the treatment of morbid obesity.(AU)

Vascular endothelial growth factor association with angiopoietin 1 promotes improvement in ventricular function after ischemic cardiomyopathy induced in mini pigs

Purpose: To investigate the safety and clinical, hemodynamic and tissue improvement ability in mini pigs undergoing cell and gene therapy for the treatment of acute myocardial infarction. Methods: Thirty-two mini pigs Br1 lineage, 12 months old, undergoing induction of acute myocardial infarction by occlusion of the diagonal branch of the paraconal coronary. They were divided into 4 groups: one control group and 3 treatment groups (cell therapy and gene cell therapy). Echocardiography reviews were performed on three occasions and histopathological analysis was performed after 4 weeks. Analysis of variance (ANOVA), Tukey and Wilcoxon tests, were performed. Results: Association of vascular endothelial growth factor (VEGF) with angiopoietin1 (Ang1) presented satisfactory results in the improvement of ventricular function following ischemic cardiomyopathy in mini pigs when compared to the results of the other treated groups. Conclusion: The therapy with VEGF and the combination of VEGF with Ang1, promoted recovered function of the myocardium, characterized by reduced akinetic area and induction of neovascularization.(AU)

Comparison among bone marrow mesenchymal stem and mononuclear cells to promote functional recovery after spinal cord injury in rabbits

Purpose: To investigate the efficacy of allogeneic mesenchymal stem-cells and autologous mononuclear cells to promote sensorimotor recovery and tissue rescue. Methods: Female rabbits were submitted to the epidural balloon inflation method and the intravenous cells administrations were made after 8 hours or seven days after injury induction. Sensorimotor evaluation of the hindlimbs was performed, and the euthanasia was made thirty days after the treatment. Spinal cords were stained with hematoxylin and eosin. Results: Both therapies given 8 hours after the injury promoted the sensorimotor recovery after a week. Only the group treated after a week with mononuclear cells showed no significant recovery at post-injury day 14. In the days 21 and 28, all treatments promoted significant recovery. Histopathological analysis showed no difference among the experimental groups. Our results showed that both bone marrow-derived cell types promoted significant sensorimotor recovery after injury, and the treatment made at least a week after injury is efficient. Conclusion: The possibilities of therapy with bone marrow-derived cells are large, increasing the therapeutic arsenal for the treatment of spinal cord injury.(AU)

Princípios da microcirurgia / Elements of microsurgery / Elementos de la microcirugía

A microcirurgia é o conjunto de procedimentos cirúrgicos realizados com o auxílio de um meio óptico de magnificação. Constitui uma das áreas tecnicamente mais sofisticadas da prática médica, que combina precisão manual, experiência técnica e conhecimento de ciências básicas. Na medicina veterinária vêm sendo aplicada tanto na realização de projetos de pesquisa na área de medicina experimental, quanto em procedimentos dentro da rotina da clínica cirúrgica. O treinamento é um processo longo e difícil, que requer grande habilidade manual, paciência, dedicação exclusiva e treinamento contínuo. Seguindo uma rotina básica de treino, o cirurgião dominará as técnicas e proporcionará aos pacientes, uma melhor qualidade de vida, pois será capaz de realizar procedimentos de reconstrução tecidual, para reparação de defeitos específicos, transplantes de órgãos, entre diversas outras técnicas.(AU)

Microsurgery is the set of surgical procedures performed with the aid of an optical magnifying means. Is one of the most technically sophisticated areas of medical practice that combines manual precision, technical experience and knowledge of basic sciences. In veterinary medicine are being applied both in conducting research projects in the area of experimental medicine, as in routine procedures within the surgical clinic. Trainingis a long and difficult process, which requires great dexterity, patience, dedication exclusive and continuous training. Following a basic workout routine, the surgeon will master the techniques and will give patients a better quality of life, it will be able to perform procedures for tissue reconstruction to repair specific defects, organ transplants, among many other techniques.(AU)

La microcirugía es un conjunto de procedimientos quirúrgicos realizados con la ayuda de un media óptico de magnificación. Contituye una de las áreas técnicamente mas sofisticadas de la práctica médica, que combina precisión manual, experiencia técnica y conocimiento de las ciencias básicas. En la medicina veterinaria viene siendo aplicada tanto en la realización de proyectos de investigación en el área de la medicina experimental, como en procedimientos dentro de la rutina de la clínica quirúrgica. El entrenamiento es un proceso largo y difícil, que requiere de grande habilidad manual, paciencia, dedicación exclusiva y entrenamiento contínuo. Siguiendo una rutina básica de entrenamiento el cirujano dominará las técnicas y proporcionará a los pacientes una mejor calidad de vida, pues será capaz de realizar procedimientos de reconstrucción de tejidos para la reparación de defectos específicos, transplantes de órganos, entre otras técnicas.(AU)

Princípios da microcirurgia / Elements of microsurgery / Elementos de la microcirugía

A microcirurgia é o conjunto de procedimentos cirúrgicos realizados com o auxílio de um meio óptico de magnificação. Constitui uma das áreas tecnicamente mais sofisticadas da prática médica, que combina precisão manual, experiência técnica e conhecimento de ciências básicas. Na medicina veterinária vêm sendo aplicada tanto na realização de projetos de pesquisa na área de medicina experimental, quanto em procedimentos dentro da rotina da clínica cirúrgica. O treinamento é um processo longo e difícil, que requer grande habilidade manual, paciência, dedicação exclusiva e treinamento contínuo. Seguindo uma rotina básica de treino, o cirurgião dominará as técnicas e proporcionará aos pacientes, uma melhor qualidade de vida, pois será capaz de realizar procedimentos de reconstrução tecidual, para reparação de defeitos específicos, transplantes de órgãos, entre diversas outras técnicas.

Microsurgery is the set of surgical procedures performed with the aid of an optical magnifying means. Is one of the most technically sophisticated areas of medical practice that combines manual precision, technical experience and knowledge of basic sciences. In veterinary medicine are being applied both in conducting research projects in the area of experimental medicine, as in routine procedures within the surgical clinic. Trainingis a long and difficult process, which requires great dexterity, patience, dedication exclusive and continuous training. Following a basic workout routine, the surgeon will master the techniques and will give patients a better quality of life, it will be able to perform procedures for tissue reconstruction to repair specific defects, organ transplants, among many other techniques.

La microcirugía es un conjunto de procedimientos quirúrgicos realizados con la ayuda de un media óptico de magnificación. Contituye una de las áreas técnicamente mas sofisticadas de la práctica médica, que combina precisión manual, experiencia técnica y conocimiento de las ciencias básicas. En la medicina veterinaria viene siendo aplicada tanto en la realización de proyectos de investigación en el área de la medicina experimental, como en procedimientos dentro de la rutina de la clínica quirúrgica. El entrenamiento es un proceso largo y difícil, que requiere de grande habilidad manual, paciencia, dedicación exclusiva y entrenamiento contínuo. Siguiendo una rutina básica de entrenamiento el cirujano dominará las técnicas y proporcionará a los pacientes una mejor calidad de vida, pues será capaz de realizar procedimientos de reconstrucción de tejidos para la reparación de defectos específicos, transplantes de órganos, entre otras técnicas.

Morpho-pathological and ultrastructural analysis of the murinemelanoma B16F10 and B16F0 cell lines and derived tumors / Anáalise morfo-patolóogica e ultraestrutural de linhagens celulares B16F10 E B16F0 e melanoma decamundongo e tumores derivados

Murine B16 cell lines of tumorigenic melanocytes have been widely used as cellular model for biochemicaland molecular studies in melanoma research. Despite such importance there is still a lack of information onthe microanatomy and cytopathology of these B16 models. The aim of this study was to shed light on themorpho-pathological specificities of the murine melanoma cell lines B16F10 and B16F0, and derived tumors,and correlate the findings with distinct metastatic potential. Cyto- and histopathological analysis carried outby optical and transmission electron microscopy (TEM) revealed that both tumor cell lines exhibit typicalfeatures of carcinogenic cells such as atypical mitoses, multiple nucleoli and enlarged nucleus. In agreementwith their highest metastatic potential, B16F10 cells and tumors exhibited more aberrant morphology thanthat observed in B16F0 samples. Also the histopathological analysis revealed that only the B16F10 tumor cellscould invade adjacent muscle tissues. Under TEM, B16F0 cell line presented mitochondrial hyperplasia andhypertrophia and a large number of melanosomes, while B16F10 showed a larger number of mitochondria ina wider range of shapes and sizes, numerous polyribosomes, cellular peripheral fibrillar material, and abnormalclusters of mitochondria. These morphological features related to the differential metastatic potentials ofB16F10 and B16F0, provide new insights on the cellular changes involved in melanoma metastatic progressionand also would be instrumental to expand the application of these cell lines as models in melanoma research.AU

Linhas de células B16 de melanócitos tumorais de camundongos têm sido amplamente utilizadascomo modelo celular para estudos bioquímicos e moleculares na pesquisa de melanoma. Apesardessa importância, ainda há uma falta de informação sobre a micro anatomia e citopatologia destesmodelos B16. O objetivo deste estudo foi pesquisar sobre as especificidades morfo-patológicas das linhasde células de melanoma de camundongos B16F10 e B16F0 e tumores derivados, e correlacionaros achados com potencial metastático distinto. Cito e análise histopatológica realizada por microscopiaóptica e eletrônica de transmissão (TEM) revelou que ambas as linhagens celulares tumoraisexibem características típicas de células cancerígenas, como mitoses atípicas, múltiplos nucléolos enúcleo aumentado. De acordo com seu potencial mais elevado, as células B16F10 e tumores metastáticosexibiram morfologia mais aberrante do que a observada em amostras de B16F0. A análisehistopatológica também revelou que apenas as células tumorais B16F10 poderiam invadir os tecidosmusculares adjacentes. De acordo com TEM, a linhagem de células B16F0 apresentou hiperplasiae hipertrofia mitocondrial e um grande número de melanossomas, enquanto B16F10 demonstrouum maior número de mitocôndrias em uma ampla gama de formas e tamanhos, numerosos polirribossomas,material fibrilar celular periférico e aglomerados de mitocôndrias anormais. Estascaracterísticas morfológicas relacionadas aos diferenciais pote nciais metastáticos de B16F10 e B16F0forneceram novas compreensões sobre as mudanças celulares envolvidas na progressão metastáticade melanoma e também seria fundamental para ampliar a aplicação dessas linhagens celulares comomodelo na pesquisa melanoma.(AU)

Morpho-pathological and ultrastructural analysis of the murinemelanoma B16F10 and B16F0 cell lines and derived tumors / Anáalise morfo-patolóogica e ultraestrutural de linhagens celulares B16F10 E B16F0 e melanoma decamundongo e tumores derivados

Murine B16 cell lines of tumorigenic melanocytes have been widely used as cellular model for biochemicaland molecular studies in melanoma research. Despite such importance there is still a lack of information onthe microanatomy and cytopathology of these B16 models. The aim of this study was to shed light on themorpho-pathological specificities of the murine melanoma cell lines B16F10 and B16F0, and derived tumors,and correlate the findings with distinct metastatic potential. Cyto- and histopathological analysis carried outby optical and transmission electron microscopy (TEM) revealed that both tumor cell lines exhibit typicalfeatures of carcinogenic cells such as atypical mitoses, multiple nucleoli and enlarged nucleus. In agreementwith their highest metastatic potential, B16F10 cells and tumors exhibited more aberrant morphology thanthat observed in B16F0 samples. Also the histopathological analysis revealed that only the B16F10 tumor cellscould invade adjacent muscle tissues. Under TEM, B16F0 cell line presented mitochondrial hyperplasia andhypertrophia and a large number of melanosomes, while B16F10 showed a larger number of mitochondria ina wider range of shapes and sizes, numerous polyribosomes, cellular peripheral fibrillar material, and abnormalclusters of mitochondria. These morphological features related to the differential metastatic potentials ofB16F10 and B16F0, provide new insights on the cellular changes involved in melanoma metastatic progressionand also would be instrumental to expand the application of these cell lines as models in melanoma research.

Linhas de células B16 de melanócitos tumorais de camundongos têm sido amplamente utilizadascomo modelo celular para estudos bioquímicos e moleculares na pesquisa de melanoma. Apesardessa importância, ainda há uma falta de informação sobre a micro anatomia e citopatologia destesmodelos B16. O objetivo deste estudo foi pesquisar sobre as especificidades morfo-patológicas das linhasde células de melanoma de camundongos B16F10 e B16F0 e tumores derivados, e correlacionaros achados com potencial metastático distinto. Cito e análise histopatológica realizada por microscopiaóptica e eletrônica de transmissão (TEM) revelou que ambas as linhagens celulares tumoraisexibem características típicas de células cancerígenas, como mitoses atípicas, múltiplos nucléolos enúcleo aumentado. De acordo com seu potencial mais elevado, as células B16F10 e tumores metastáticosexibiram morfologia mais aberrante do que a observada em amostras de B16F0. A análisehistopatológica também revelou que apenas as células tumorais B16F10 poderiam invadir os tecidosmusculares adjacentes. De acordo com TEM, a linhagem de células B16F0 apresentou hiperplasiae hipertrofia mitocondrial e um grande número de melanossomas, enquanto B16F10 demonstrouum maior número de mitocôndrias em uma ampla gama de formas e tamanhos, numerosos polirribossomas,material fibrilar celular periférico e aglomerados de mitocôndrias anormais. Estascaracterísticas morfológicas relacionadas aos diferenciais pote nciais metastáticos de B16F10 e B16F0forneceram novas compreensões sobre as mudanças celulares envolvidas na progressão metastáticade melanoma e também seria fundamental para ampliar a aplicação dessas linhagens celulares comomodelo na pesquisa melanoma.