Mapping the learning styles of medical students in Brazil.

BACKGROUND: Medical education has evolved based on the application of pedagogical actions that place the student as the protagonist of the learning process through the use of active teaching methodologies. Within this context, higher education teachers should use strategies that focus on the student and his/her context and avoid traditional teaching methods. Specifically in medical schools, there is an even greater challenge since the teaching methods of medical curricula differ from those used in previous schooling. Consequently, students acquire their own style of processing information that is often incompatible with the profile of medical schools. This may be one of the factors responsible for the lack of motivation among undergraduates. OBJECTIVE: The aim of this study was to characterize the learning styles of students enrolled in a Brazilian medical school using the Felder-Soloman Index of Learning Styles (ILS). METHODS: This was a cross-sectional, descriptive, quantitative study that included students from the 1st to the 6th year of a Brazilian medical school. The students participating in this study voluntarily answered 44 questions about learning styles of the Felder-Silverman instrument validated in Brazil. The instrument was divided so that each domain consisted of 11 questions with two response options in which only one could be selected. For each domain, a score (1 point) was assigned to the selected option (a, b) of the question and the learning style category was determined as the difference between these values. For data collection and tabulation, we used the Learning Syle Platform (EdA Platform) developed based on Felder's studies since this system processes information about the dimension analyzed, the preferred style, and the most striking characteristics of each style. RESULTS: The results showed that sensing was the preferred learning style of the students, followed by the sequential and visual styles. It was not possible to determine whether gender or age influences the choice of learning methods because of the homogeneity of the results. CONCLUSIONS: The present data will enable teachers of the institution involved in this study to plan pedagogical actions that improve the students' self-awareness, as well as their teaching-learning skills, by choosing the most adequate active methodologies for the medical education programs considering the individuality of each student and class.

In Vivo Evaluation of Collagen and Chitosan Scaffold, Associated or Not with Stem Cells, in Bone Repair.

Natural polymers are increasingly being used in tissue engineering due to their ability to mimic the extracellular matrix and to act as a scaffold for cell growth, as well as their possible combination with other osteogenic factors, such as mesenchymal stem cells (MSCs) derived from dental pulp, in an attempt to enhance bone regeneration during the healing of a bone defect. Therefore, the aim of this study was to analyze the repair of mandibular defects filled with a new collagen/chitosan scaffold, seeded or not with MSCs derived from dental pulp. Twenty-eight rats were submitted to surgery for creation of a defect in the right mandibular ramus and divided into the following groups: G1 (control group; mandibular defect with clot); G2 (defect filled with dental pulp mesenchymal stem cells-DPSCs); G3 (defect filled with collagen/chitosan scaffold); and G4 (collagen/chitosan scaffold seeded with DPSCs). The analysis of the scaffold microstructure showed a homogenous material with an adequate percentage of porosity. Macroscopic and radiological examination of the defect area after 6 weeks post-surgery revealed the absence of complete repair, as well as absence of signs of infection, which could indicate rejection of the implants. Histomorphometric analysis of the mandibular defect area showed that bone formation occurred in a centripetal fashion, starting from the borders and progressing towards the center of the defect in all groups. Lower bone formation was observed in G1 when compared to the other groups and G2 exhibited greater osteoregenerative capacity, followed by G4 and G3. In conclusion, the scaffold used showed osteoconductivity, no foreign body reaction, malleability and ease of manipulation, but did not obtain promising results for association with DPSCs.

Renal, hepatic and muscle effects of creatine supplementation in an older adults experimental model.

BACKGROUND & AIMS: Creatine is a dietary supplement with potential capacity to stimulate the phosphocreatine pathway and protein synthesis, through the stimulation of the PI3-K/AKT and mTOR cascade, its use in populations with reduced muscle preservation capacity (such as the older adults) can be an interesting and low-cost alternative. The aim of the present study was to evaluate the morphological, stereological and morphometric effects of the use of creatine monohydrate for 8 weeks on the renal, hepatic and muscular tissues of 26-month-old Wistar rats. METHODS: Twelve Wistar rats were divided into two groups of six animals each. Group 1 was not supplemented with creatine and received a standard diet consisting of water and chow. Group 2 received the same diet, but was supplemented with creatine monohydrate at a dose of 0.3 mg/kg of body weight diluted in 200 ml of drinking water for 8 weeks. RESULTS: Supplementation reduced muscle mass loss as indicated by the perimeter of the perimysium (group 1: 114.6 µm; group 2: 65.2 µm) and endomysium (group 1: 41,239.3 µm; group 2: 12,437.6 µm) compared to the non-supplemented group. In addition, a larger cross-sectional area was observed in group 2. No significant kidney or liver damage was observed in the supplemented group. CONCLUSIONS: The use of creatine is considered safe in the animal model used, as this amine does not cause glomerular reductions or hepatic degeneration.

In Vivo Study of Nasal Bone Reconstruction with Collagen, Elastin and Chitosan Membranes in Abstainer and Alcoholic Rats.

The aim of the present study was to evaluate the use of collagen, elastin, or chitosan biomaterial for bone reconstruction in rats submitted or not to experimental alcoholism. Wistar male rats were divided into eight groups, submitted to chronic alcohol ingestion (G5 to G8) or not (G1 to G4). Nasal bone defects were filled with clot in animals of G1 and G5 and with collagen, elastin, and chitosan grafts in G2/G6, G3/G7, and G4/G8, respectively. Six weeks after, all specimens underwent radiographic, tomographic, and microscopic evaluations. Bone mineral density was lower in the defect area in alcoholic animals compared to the abstainer animals. Bone neoformation was greater in the abstainer groups receiving the elastin membrane and in abstainer and alcoholic rats receiving the chitosan membrane (15.78 ± 1.19, 27.81 ± 0.91, 47.29 ± 0.97, 42.69 ± 1.52, 13.81 ± 1.60, 18.59 ± 1.37, 16.54 ± 0.89, and 37.06 ± 1.17 in G1 to G8, respectively). In conclusion, osteogenesis and bone density were more expressive after the application of the elastin matrix in abstainer animals and of the chitosan matrix in both abstainer and alcoholic animals. Chronic alcohol ingestion resulted in lower bone formation and greater formation of fibrous connective tissue.

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.

Effects of the combination of low-level laser therapy and anionic polymer membranes on bone repair.

In view of the limitations of bone reconstruction surgeries using autologous grafts as a gold standard, tissue engineering is emerging as an alternative, which permits the fabrication and improvement of scaffolds to stimulate osteogenesis and angiogenesis, processes that are essential for bone repair. Polymers are used to mimic the extracellular bone matrix and support cell growth. In addition, bone neoformation can be induced by external factors such as laser irradiation, which stimulates bone metabolism. The objective of this study was to evaluate the regeneration of bone defects using collagen and elastin membranes derived from intestinal serosa and bovine auricular cartilage combined with low-level laser application. Thirty-six Wistar rats were operated to create a 3-mm defect in the distal metaphysis of the left femur and divided into six groups: G1 (control, no treatment); G2 (laser); G3 (elastin graft), G4 (elastin+laser); G5 (collagen graft); G6 (collagen+laser). The animals were sacrificed 6 weeks after surgery and the femurs were removed for analysis of bone repair. Macroscopic and radiological results showed the absence of an infectious process in the surgical area. This was confirmed by histological analysis, which revealed no inflammatory infiltrate. Histomorphometry showed that the formation of new bone started from the margins of the bone defect and its volume was greater in elastin+laser and collagen+laser. We conclude that newly formed bone in the graft area was higher in the groups that received the biomaterials and laser. The collagen and elastin matrices showed biocompatibility.

Suitability of the use of an elastin matrix combined with bone morphogenetic protein for the repair of cranial defects.

The use of biomaterials in medical and dental areas has become increasingly important due to the need to restore areas with bone loss or defects. This study analyzed the use of a new elastin polymer matrix combined with Bone Morphogenetic Protein for the repair of cranial defects in rats. Thirty rats were divided into five groups: control (C) defect without graft, E24 (defect filled with elastin matrix submitted to alkaline hydrolysis at 50°C for 24 h), E24/BMP (defect filled with elastin matrix treated at 50°C for 24 h plus BMP), E96 (defect filled with elastin matrix treated at 37°C for 96 h) and E96/BMP (defect filled with elastin matrix treated at 37°C for 96 h plus BMP). The animals were killed after 6 weeks. In the histological and microtomographic analysis, all groups showed bone growth from the defect margins remaining in this region without a marked inflammatory process, but in the E96/BMP group the lamellae were thicker and the collagen fibers more organized. Histometrically, the same group presented higher percentage of new formation (43.25 ± 3.72) in relation to the other groups. It was concluded that the support and delivery system formed by the elastin matrix associated with BMPs had a positive effect on the bone repair process.

Infraclavicular topography of the brachial plexus fascicles in different upper limb positions / Topografía infraclavicular de los fascículos del plexo braquial en diferentes posiciones del miembro superior

Brachial plexus neuropathies are common complaints among patients seen at orthopedic clinics. The causes range from traumatic to occupational factors and symptoms include paresthesia, paresis, and functional disability of the upper limb. Treatment can be surgical or conservative, but detailed knowledge of the brachial plexus is required in both cases to avoid iatrogenic injuries and to facilitate anesthetic block, preventing possible vascular punctures. Therefore, the objective of this study was to evaluate the topography of the infraclavicular brachial plexus fascicles in different upper limb positions adopted during some clinical procedures. A formalin-preserved, adult, male cadaver was used. The infraclavicular and axillary regions were dissected and the distance of the brachial plexus fascicles from adjacent bone structures was measured. No anatomical variation in the formation of the brachial plexus was observed. The metric relationships between the brachial plexus and adjacent bone prominences differed depending on the degree of shoulder abduction. Detailed knowledge of the infraclavicular topography of neurovascular structures helps with the diagnosis and especially with the choice of conservative or surgical treatment of brachial plexus neuropathies.

Las neuropatías del plexo braquial son quejas comunes entre los pacientes atendidos en las clínicas ortopédicas. Las causas van desde traumas a factores ocupacionales y los síntomas incluyen parestesias, paresia e incapacidad funcional del miembro superior. El tratamiento puede ser quirúrgico o conservador, pero se requiere un conocimiento detallado del plexo braquial en ambos casos para evitar lesiones iatrogénicas y para facilitar el bloqueo anestésico, evitando posibles lesiones vasculares. Por lo tanto, el objetivo de este estudio fue evaluar la topografía de los fascículos del plexo braquial infraclavicular en diferentes posiciones de los miembros superiores adoptadas durante algunos procedimientos clínicos. Se llevó a cabo la disección de las regiones infraclavicular y axilar de un cadáver adulto, de sexo masculino, conservado en formaldehído. Se midió la distancia de los fascículos del plexo braquial en relación a las estructuras óseas adyacentes. No se observó variación anatómica en la formación del plexo braquial. Las relaciones métricas entre el plexo braquial y las prominencias óseas adyacentes difieren en función del grado de abducción del hombro. El conocimiento detallado de la topografía infraclavicular de las estructuras neurovasculares ayuda con el diagnóstico y sobre todo con la elección del tratamiento conservador o quirúrgico de las neuropatías del plexo braquial.

Use of a New Fibrin Sealant and Laser Irradiation in the Repair of Skull Defects in Rats

This study evaluated the osteogenic capacity of a new fibrin sealant (FS) combined with bone graft and laser irradiation in the bone repair. Defects were created in the skull of 30 rats and filled with autogenous graft and FS derived from snake venom. Immediately after implantation, low-power laser was applied on the surgical site. The animals were divided in: control group with autogenous graft (G1), autogenous graft and laser 5 J/cm2 (G2), autogenous graft and laser 7 J/cm2 (G3), autogenous graft and FS (G4), autogenous graft, FS and laser 5 J/cm2 (G5), autogenous graft, FS and laser 7 J/cm2 (G6). The animals were sacrificed 6 weeks after implant. Results showed absence of inflammatory infiltrate in the bone defect. New bone formation occurred in all groups, but it was most intense in G6. Thus, the FS and laser 7 J/cm2 showed osteoconductive capacity and can be an interesting resource to be applied in surgery of bone reconstruction.

Este estudo avaliou a capacidade osteogênica de um novo selante de fibrina (FS) associado com enxerto ósseo e irradiação laser no reparo ósseo. Defeitos foram criados no crânio de 30 ratos e preenchidos com enxerto autógeno e FS derivado do veneno de cobra. Imediatamente após implantação, foi aplicado laser de baixa potência na área cirúrgica. Os animais foram divididos em grupo controle com autógeno (G1), autógeno e laser 5 J/cm2 (G2), autógeno e laser 7J/cm2 (G3), autógeno e FS (G4), autógeno, FS e laser 5J/cm2 (G5), autógeno, FS e laser 7J/cm2 (G6). Os animais foram sacrificados 6 semanas após implante. Resultados mostraram ausência de infiltrado inflamatório no defeito ósseo. Neoformação óssea ocorreu em todos os grupos, entretanto, foi mais intenso em G6. Desta maneira, o FS e laser 7J/cm2 mostraram capacidade osteocondutiva e podem ser um interessante recurso a ser aplicado nas cirurgias de reconstrução óssea.

Use of a new fibrin sealant and laser irradiation in the repair of skull defects in rats.

This study evaluated the osteogenic capacity of a new fibrin sealant (FS) combined with bone graft and laser irradiation in the bone repair. Defects were created in the skull of 30 rats and filled with autogenous graft and FS derived from snake venom. Immediately after implantation, low-power laser was applied on the surgical site. The animals were divided in: control group with autogenous graft (G1), autogenous graft and laser 5 J/cm2 (G2), autogenous graft and laser 7 J/cm2 (G3), autogenous graft and FS (G4), autogenous graft, FS and laser 5 J/cm2 (G5), autogenous graft, FS and laser 7 J/cm2 (G6). The animals were sacrificed 6 weeks after implant. Results showed absence of inflammatory infiltrate in the bone defect. New bone formation occurred in all groups, but it was most intense in G6. Thus, the FS and laser 7 J/cm2 showed osteoconductive capacity and can be an interesting resource to be applied in surgery of bone reconstruction.

Median Nerve Behavior in Different Upper Limb Positions / Comportamiento del Nervio Mediano en Diferentes Posiciones del Miembro Superior

The neural compression syndromes peripheral upper limb are common in clinical medicine and the causes range from trauma and occupational factors. Technical evaluation manuals as neural tension at different positions of the upper limb as well as knowledge of the topography of the affected nerve are essential for accurate diagnosis. The objective of this study was to analyze the behavior of the median nerve in different positions of the upper limb. Fifteen formalin-fixed cadavers were used for morphometric and topographic evaluation of the median nerve in different positions of the right upper limb. In all cases analyzed, the median nerve originated from the lateral and medial fascicles of the brachial plexus and attended by the arm and forearm in accordance with the classical descriptions in the literature. Measurement of the length of the nerve in different positions of the upper limb showed greater stretching during the position that combined extension and external rotation of the shoulder and extension of the elbow/wrist/fingers. In conclusion, the metric landmarks and positions studied are important for the precise diagnosis of median nerve neurobiomechanics in nerve compression syndromes.

Los síndromes de compresión de los nervios periféricos del miembro superior son comunes en la medicina clínica, y sus causas comprenden traumas y factores ocupacionales. Manuales de evaluación técnica y la tensión neural en diferentes posiciones del miembro superior, así como el conocimiento de la topografía del nervio afectado, son esenciales para un diagnóstico preciso. El objetivo de este estudio fue analizar el comportamiento del nervio mediano en diferentes posiciones del miembro superior. Fueron utilizados 15 cadáveres fijados en formol. Se realizó la evaluación morfométrica y topográfica del nervio mediano en diferentes posiciones del miembro superior derecho. En todos los casos analizados, el nervio mediano se originó desde los fascículos lateral y medial del plexo braquial, y recorrieron el brazo y el antebrazo de acuerdo con las descripciones clásicas. La medición de la longitud del nervio en las diferentes posiciones mostró un mayor estiramiento durante la posición combinada de extensión y rotación lateral del hombro y extensión del codo/muñeca/dedos. En conclusión, los puntos de referencia y posiciones métricas estudiadas son importantes para un diagnóstico sdrcusdo de la neurobiomecánica del nervio mediano en los síndromes de compresión nerviosa.

Osteoconductive capacity of hydroxyapatite implanted into the skull of diabetics.

Diabetes mellitus can cause various diseases, including loss of bone mineral density as a characteristic manifestation of osteoporosis. In this condition, bone is more vulnerable to pathologic fractures that can be treated by implantation of biomaterial grafts. The aim of this study was to evaluate the osteogenic capacity of hydroxyapatite implanted into bone defects in the skull of nonobese diabetic mice. Fifteen nonobese diabetic mice were divided into 3 groups: control (nondiabetic), spontaneously diabetic, and spontaneously diabetic receiving insulin replacement applied subcutaneously into the dorsum. Defects were created experimentally in the skull with a surgical bur and filled with hydroxyapatite granules. The animals were killed 4 weeks after surgery, and samples were obtained for analysis. Quantitative methods were used for measurement of the new bone formation. Data were analyzed by analysis of variance followed by the Tukey test (P < 0.05). Radiographic results showed good radiopacity of the hydroxyapatite; however, radiolucent spots were seen between the hydroxyapatite granules in the diabetic groups, indicating infiltration of connective tissue. Microscopic results showed projections of newly formed bone from the margin of bone defect toward the implant. The quantity of newly formed bone was significantly higher (P < 0.05) than that observed in the diabetic groups. The recipient area of diabetic groups contained a larger amount of connective tissue as demonstrated by radiographic analyses. In conclusion, the osteogenesis guided by the properties of hydroxyapatite may even occur in bone suffering from the effects of diabetes, but the quantity of newly formed bone is lower, and the process is slower.