Three-Dimensional Printing of Graphene Oxide/Poly-L-Lactic Acid Scaffolds Using Fischer-Koch Modeling.

Accurately printing customizable scaffolds is a challenging task because of the complexity of bone tissue composition, organization, and mechanical behavior. Graphene oxide (GO) and poly-L-lactic acid (PLLA) have drawn attention in the field of bone regeneration. However, as far as we know, the Fischer-Koch model of the GO/PLLA association for three-dimensional (3D) printing was not previously reported. This study characterizes the properties of GO/PLLA-printed scaffolds in order to achieve reproducibility of the trabecula, from virtual planning to the printed piece, as well as its response to a cell viability assay. Fourier-transform infrared and Raman spectroscopy were performed to evaluate the physicochemical properties of the nanocomposites. Cellular adhesion, proliferation, and growth on the nanocomposites were evaluated using scanning electron microscopy. Cell viability tests revealed no significant differences among different trabeculae and cell types, indicating that these nanocomposites were not cytotoxic. The Fischer Koch modeling yielded satisfactory results and can thus be used in studies directed at diverse medical applications, including bone tissue engineering and implants.

Development of an interactive multidisciplinary platform for the bovine neuroanatomy study / Desarrollo de una plataforma interactiva multidisciplinar para el estudio de la neuroanatomía bovina

SUMMARY: The anatomy study is part of the basic cycle of disciplines that composes Veterinary Medicine college curriculum, and its comprehension is essential for other courses subject understanding. However, the current student's profile, the reduced time frame of superior education programs, and the multidisciplinary approach nowadays have made anatomy teaching method outdated and ineffective. Addressing the problem we developed an interactive and multidisciplinary platform based on the blended learning methodology, which could serve as a valuable tool for bovine neuroanatomy comprehension. To produce a new study tool, photos from bovine specimens fixed in formaldehyde, platinated brain pieces sectioned in a metameric order, as well as histological slides of the bovine central nervous system were used. These materials were applied to photos and schemes production, that were correlated with image exams correlation, as well as written content and videotaped classes. The obtained content was compiled into a digital platform, that can serve as an effective additional method to bovine central nervous system study. Furthermore, our results serve as a guide for the development of other blended learning methodologies in veterinary medicine and anatomy teaching. The platform provides a great tool for those who wish to accomplish a better understanding of bovine neuroanatomy and its clinical, surgical and image diagnosis correlations.

El estudio de la anatomía forma parte del ciclo básico de disciplinas que componen el currículo de la facultad de Medicina Veterinaria, y su comprensión es fundamental para el entendimiento de las materias de otros cursos. Sin embargo, el perfil del estudiante actual, la reducción de los tiempos de los programas de educación superior y el enfoque multidisciplinario actual han hecho que el método de enseñanza de la anatomía sea obsoleto e ineficaz. Abordando el problema desarrollamos una plataforma interactiva y multidisciplinar basada en la metodología blended learning, que podría servir como una valiosa herramienta para la comprensión de la neuroanatomía bovina. Para producir una nueva herramienta de estudio, se utilizaron fotografías de especímenes bovinos fijados en formaldehído, piezas de cerebro plastinadas y seccionadas en un orden metamérico, así como láminas histológicas del sistema nervioso central bovino. Estos materiales se utilizaron en la producción de fotos y esquemas, que se correlacionaron con exámenes de imágenes, así como contenido escrito y clases grabadas en video. El contenido obtenido se compiló en una plataforma digital, que puede servir como un método adicional y eficaz para el estudio del sistema nervioso central bovino. Además, nuestros resultados sirven como guía para el desarrollo de otras metodologías de aprendizaje semipresencial en la enseñanza de la medicina veterinaria y la anatomía. La plataforma proporciona una gran herramienta para aquellos que deseen lograr una mejor comprensión de la neuroanatomía bovina y sus correlaciones clínicas, quirúrgicas y de diagnóstico por imágenes.

Evaluation of the degradation of two bioabsorbable interference screws: an in-vivo study in sheep.

PURPOSE: To evaluate in-vivo degradation of two bioabsorbable interference screws. METHODS: Twenty-two crossbred Santa Inês ewes were used. A poly-DL-lactide (PDLLA) screw (70%/30%) was inserted in the right pelvic limb, and a PDLLA screw (70%) + ß-tri-calcium phosphate (ß-TCP) (30%) in the left pelvic limb. Animals were euthanized at one, four, seven and a half and 18 months after surgery. Plain radiography, computed tomography (CT), microCT, and histological analysis were accomplished. RESULTS: PDLLA screw was hypodense at all evaluation moments, but with progressive density increase along the central axis, whereas PDLLA/ß-TCP was initially hyperdense and progressively lost this characteristic. No adverse reactions were observed on histological evaluation. CONCLUSIONS: The inclusion of ß-TCP favors screw degradation since the PDLLA/ß-TCP screws evidenced a more intense degradation process than the PDLLA screws at the last evaluation. PDLLA screws showed higher bone production, evident around the screw thread, inside the lateral perforations, and in the central canal, whereas the PDLLA/ß-TCP screws presented less bone tissue at the implantation site.

Osseointegration Improvement of Co-Cr-Mo Alloy Produced by Additive Manufacturing.

Cobalt-base alloys (Co-Cr-Mo) are widely employed in dentistry and orthopedic implants due to their biocompatibility, high mechanical strength and wear resistance. The osseointegration of implants can be improved by surface modification techniques. However, complex geometries obtained by additive manufacturing (AM) limits the efficiency of mechanical-based surface modification techniques. Therefore, plasma immersion ion implantation (PIII) is the best alternative, creating nanotopography even in complex structures. In the present study, we report the osseointegration results in three conditions of the additively manufactured Co-Cr-Mo alloy: (i) as-built, (ii) after PIII, and (iii) coated with titanium (Ti) followed by PIII. The metallic samples were designed with a solid half and a porous half to observe the bone ingrowth in different surfaces. Our results revealed that all conditions presented cortical bone formation. The titanium-coated sample exhibited the best biomechanical results, which was attributed to the higher bone ingrowth percentage with almost all medullary canals filled with neoformed bone and the pores of the implant filled and surrounded by bone ingrowth. It was concluded that the metal alloys produced for AM are biocompatible and stimulate bone neoformation, especially when the Co-28Cr-6Mo alloy with a Ti-coated surface, nanostructured and anodized by PIII is used, whose technology has been shown to increase the osseointegration capacity of this implant.

The macro and micro-structure of the celiac and cranial mesenteric ganglia in a long-lived rodent - paca (Cuniculus paca, Linnaeus 1766) / La macro y micro estructura de los ganglios mesentéricos celíacos y craneales en un roedor longevo - paca (Cuniculus paca, Linnaeus 1766)

SUMMARY: The celiac, cranial mesenteric and celiacomesenteric ganglia of the paca (Cuniculus paca) were found between the celiac and cranial mesenteric arteries. Two predominant patterns were found: isolated celiac and cranial mesenteric ganglion and the celiacomesenteric ganglion. At the microscopic level, the ganglia are constituted by an agglomeration of neurons surrounded by capsule of connective tissue. Most of these neurons had a single eccentric nucleus. Satellite cells and mast cells were found around the soma. The mast cells were also found ar ound blood vessels and in the capsule of the ganglia.

RESUMEN: Los ganglios celíacos, mesentérico-craneales y celíaco mesentéricos de la paca (Cuniculus paca) se encontraron entre las arterias celíaca y mesentérica craneal. Se visalizaron dos patrones predominantes: celiaca aislada y ganglio mesentérico craneal y ganglio celiaco mesentérico. A nivel microscópico, los ganglios están constituidos por una aglomeración de neuronas rodeadas por una cápsula de tejido conectivo. La mayoría de estas neuronas tenían un solo núcleo excéntrico. Se encontraron células satélites y mastocitos alrededor del soma. Los mastocitos también se encontraron alrededor de los vasos sanguíneos y en la cápsula de los ganglios.

Serological survey and DNA screening of Leptospira spp. in free-living adult tufted capuchin monkeys (Cebus apella nigritus) in a forest reserve Southeast São Paulo State, Brazil.

BACKGROUND: Leptospirosis is an important anthropozoonosis. The study investigated the presence of anti-Leptospira antibodies and detection of Leptospira spp DNA in the urine as well as the biochemical profile in Neotropical wild primates living in a forest reserve from Southeast São Paulo State, Brazil. METHODS: Blood samples were obtained from 50 adult tufted capuchin monkeys (Cebus apella nigritus). Urine samples were obtained only from male primates. The screening for antibodies against Leptospira spp was evaluated by microscopic agglutination test (MAT). Leptospira DNA in the urine was evaluated by polymerase chain reaction (PCR) considering the target gene LipL32. Biochemical profile was evaluated by using a spectrophotometer. RESULTS: The MAT results included 39 (78%) serum reactive animals with the proportions of 28/39 males and 11/39 females. The most frequent reactive serogroups were Icterohemorrhagiae, Canicola, and Autumnalis. All urine samples were negative for leptospiral DNA. There were no significant differences between sexes for aspartate aminotransferase (AST) and alkaline phosphatase values, but alanine aminotransferase (ALT), creatinine, glucose, and urea were significantly higher in males. CONCLUSIONS: Tufted capuchin monkeys were sera reactive against leptospirosis. Prevalence was similar for the 2 sexes. Leptospiral DNA was not detected in the urine of sera reactive primates tested by the MAT method. ALT, creatinine, glucose, and urea values were higher in male animals.

Radiographic determination of pelvic limb orthopaedic measurements in maned wolf (Chrysocyon brachyurus).

The aim of this study was to determine some radiographic reference values for hip joint, femur and patella in maned wolves. Ten maned wolves (Chrysocyon brachyurus), five live (G1) and five cadavers (G2), were used. There were no statistically significant differences in the radiological measurements between right and left pelvic limbs of the G1 and G2, except for mechanical lateral proximal femoral angle (mLPFA) in both Groups. The comparison of the measurements between Groups showed difference only for mechanical lateral distal femoral angle (mLDFA). Norberg angle values were 113.1° and 112.9° for G1 and G2. The values of femoral angle of inclination by Hauptman A and Hauptman B methods were 139.7° and 128.6° for G1, and 139.3° and 128.7° for G2. Femoral varus angle values were 5.5° for G1 and 3.9° for G2. The values of anatomic lateral distal femoral angle and anatomic lateral proximal femoral angle were 96.8° and 95.2° for G1, and 95.0° and 95.6° for G2. The values of mLDFA for G1 and G2 were 96.5° and 95.7°. The values of mLPFA were 95.8 (right) and 93.5 (left) for G1, and 95.7 (right) and 93.8 (left) for G2. The values of patellar ligament length, patellar length and L:P ratio were 4.6, 2.4 cm and 1.9 for G1, and 4.4, 2.3 cm and 1.8 for G2. In conclusion, the radiographic reference values described for the hip joint, the femur and the patella, may be useful in the diagnosis of diseases and deformities in maned wolves.