Regenerating effect of hyaluronic acid on circumferential bone defects in wistar albino rats / Efecto regenerador del ácido hialurónico en defectos óseos circunferenciales en ratas albinas wistar

Objective: To determine the regenerating effect of hyaluronic acid on circumferential bone defects in albino Wistar rats. Material and Methods: An experimental type study was designed and carried out with 15 albino male Wistar rats, 4 months old and weighing between 250 and 350 grams. Two circumferential bone defects 3mm in diameter and 0.8mm deep were created in the calvaria of the parietal bone (on both sides of the midline). One defect was filled with a demineralized bone matrix (control group); while the other defect was filled with the combination of a demineralized bone matrix plus hyaluronic acid (experimental group). Five experimental rats were euthanized at 30, 60 and 90 days after surgery and they were histologically evaluated following the parameters proposed by Heiple. Results: The experimental group presented a better degree of bone regeneration at 30 and 60 postoperative days. Conclusion: Hyaluronic acid is effective in bone regeneration of circumferential bone defects.

Objetivo: Determinar el efecto regenerador del ácido hialurónico en defectos óseos circunferenciales en ratas albinas Wista. Material y Métodos: Se diseñó un estudio de tipo experimental y se trabajó con 15 ratas albinas Wistar (todas macho) de 4 meses de edad y con un peso entre 250 a 350 gr. Se crearon en todas 2 defectos óseos circunferenciales de 3mm de diámetro y 0.8 mm de profundidad en la calota del hueso parietal (a ambos lados de la línea media). Un defecto fue rellenado con una matriz ósea desmineralizada (grupo control); mientras que el otro defecto fue rellenado con la combinación de una matriz ósea desmineralizada más el ácido hialurónico (grupo experimental). Se realizó la eutanasia a 05 ratas de experimentación a los 30, 60 y 90 días postquirúrgicos y se evaluaron histológicamente siguiendo los parámetros propuestos por Heiple. Resultados: El grupo experimental presentó un mejor grado de regeneración ósea en los 30 y 60 días postoperatorios. Conclusiones: El ácido hialurónico es eficaz en la regeneración ósea de defectos óseos circunferenciales.

Histological comparison between biphasic calcium phosphate and deproteinized bovine bone on critical-size bone defects

Abstract The limited options for bone repair have led to an extensive research of the field and the development of alloplastic and xenogeneic grafts. The purpose of this study was to evaluate bone repair with two bone substitutes: deproteinized bovine bone (DBB) and biphasic calcium phosphate ceramic (BCP) in critical-size defect. A total of 8-mm defects were made in the parietal bones of rabbits (n=12). The animals were divided into three experimental groups: sham (defect filled with a blood clot), DBB (defect filled with DBB), and BCP (defect filled with BCP). After the experimental periods of 15 and 45 days, the animals were euthanized and submitted to histomorphometric analysis. The total defect area, mineralized tissue area, biomaterial area, and soft tissue area were evaluated. A greater amount of immature bone tissue and biomaterial particles were observed in the BCP group compared to DBB and sham at 45 days (p<0.05). There was no difference in the qualitative pattern of bone deposition between DBB and BCP. However, the sham group did not show osteoid islands along with the defect, presenting a greater amount of collagen fibers as well in relation to the DBB and BCP groups. There was a greater number of inflammatory cells in the DBB at 45 days compared to BCP and sham groups. In conclusion, BCP and DBB are options for optimizing the use of bone grafts for maxillofacial rehabilitation. Bone defects treated with BCP showed greater deposition of bone tissue at 45 days.

Resumo As opções limitadas para reparo ósseo levaram ao desenvolvimento de abrangente pesquisa na área de enxertos aloplásticos e xenogênicos. O objetivo deste estudo foi avaliar o reparo ósseo com dois substitutos ósseos: osso bovino desproteinizado (DBB) e cerâmica fosfática de cálcio bifásica (BCP) em defeito de tamanho crítico. Material e métodos: defeitos críticos de 8 mm foram feitos nos ossos parietais de coelhos (n=12). Os animais foram divididos em três grupos experimentais: sham (defeito preenchido com coágulo sanguíneo), DBB (defeito preenchido com DBB) e BCP (defeito preenchido com BCP). Após os períodos experimentais de 15 e 45 dias, os animais foram sacrificados e submetidos à análise histomorfométrica. Foram avaliadas a área total de defeitos, área de tecidos mineralizados, área de biomateriais e área de tecidos moles. Resultados: maior quantidade de tecido ósseo imaturo e de partículas de biomaterial foram observados no grupo BCP em comparação aos grupos DBB e sham aos 45 dias (p<0,05). Não houve diferença no padrão qualitativo de deposição óssea entre DBB e BCP. Ainda, o grupo sham não apresentou ilhas osteóides ao longo do defeito, apresentando maior quantidade de fibras colágenas em relação aos grupos DBB e BCP. Houve maior quantidade de células inflamatórias no DBB aos 45 dias em comparação aos grupos BCP e sham. Conclusões: BCP e DBB são opções para otimizar o uso de enxertos ósseos na reabilitação de pacientes. Defeitos ósseos tratados com BCP mostraram maior deposição de tecido ósseo aos 45 dias.

Integration of heterologous bone matrix associated with polymethylmethacrylate in induced tibial bone defects. An experimental study in rabbits

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.

Caprine demineralized bone matrix (DBMc) in the repair of non-critical bone defects in rabbit tibias. A new bone xenograft

Abstract Purpose To evaluate the use of demineralized bone matrix of caprine origin in experimental bone defects of the tibia in New Zealand rabbits. Methods Fragments of the tibia diaphysis were collected aseptically from clinically healthy goats. The bones were sectioned into 1 cm fragments and stored at -20°C for subsequent hydrochloric acid (HCL) demineralization. A 70 mg portion of DBMc was used to fill the experimental bone defects. Twenty-four female adult New Zealand rabbits were divided into 2 groups: the MG (matrix group, left tibia) and CG (control group, right tibia). Additionally, they were separated into 4 groups with 6 animals, according to the period of analysis (15, 30, 60 and 90 days postoperatively). Using microCT, volumetric parameters were evaluated: bone volume, relationship between bone volume and total volume, bone surface area, relationship between bone surface area and total volume, number of trabeculae, trabecular thickness and trabecular separation. Results There was a statistically significant difference (P<0.05) between groups considering bone volume (BV) and bone:total volume (BV/TV), on 15, 30 and 90 days postoperatively. Control group showed a statistically significant superiority (P < 0.05) considering the mean of the variables bone surface (BS), number of trabeculae (Tb.N) and between bone surface and total volume (BS/TV) at 15 and 90 days. Conclusions Caprine demineralized bone matrix was safe and tolerable. No signs of material rejection were seen macroscopically. It is an alternative for the treatment of bone defects when autologous graft is not available or in insufficient quantities.

Comparison of morphological quantitative characteristics of the newly formed alveolar bone after the application of demineralized bone matrix and cortical bone allografts / Comparación de las características morfológicas cuantitativas del hueso alveolar recién formado después de la aplicación de matriz ósea desmineralizada y aloinjertos de hueso cortical

The allografts were used to obtain sufficient alveolar bone tissue for proper dental implant placement. The objective of the present study was to evaluate the morphological and quantitative characteristics (cellular and collagen densities) of the newly formed alveolar bone with the application of cortical bone (CB) and demineralized bone matrix (DBM) allografts. Six samples of alveolar bone tissue from 5 patients (50 ± 6.3 years) were obtained after 6 months of application of the allografts and immediately before the placement of the dental implants. The samples were fixed (buffered formaldehyde, pH7.2), decalcified (EDTA 10 %) and histologically processed (HE and Picro-Sirius) for histologic analysis. Morphological analysis revealed presence of osteocytes and trabeculae in neoformed bone tissue near the allografts and absence of inflammatory and allergic cells; the remnants of CB were located mainly in the periphery of the bone tissue and the remnants of DBM were more incorporated into the tissue. Osteogenitor cells were observed around the remaining material. The cell density was not modified in newly formed bone tissue with the application of both allografts as compared to mature bone tissue. The density of the type I and III collagens present in the osteoids interspersed with the remainder of the materials showed a tendency to increase in the samples treated with DBM. It was concluded that by the histological characteristics observed both grafts were biocompatible, however the bone treated with DBM presented better incorporation and a tendency of increase of the collagen content in the remnant region of the allografts.

Los aloinjertos son utilizados para obtener tejido óseo alveolar apropiado para la colocación correcta del implante dental. El objetivo de este trabajo fue evaluar las características morfológicas y cuantitativas (densidades celulares y de colágeno) del hueso alveolar recién formado con la aplicación de aloinjertos de hueso cortical (CB) y matriz desmineralizada de hueso (DBM). Seis muestras de tejido óseo alveolar fueron obtenidas de 5 pacientes (50 ± 6,3 años) después de 6 meses de aplicación de los aloinjertos e inmediatamente antes de la colocación de los implantes dentales. Las muestras fueron fijadas (formaldehído tamponado, pH 7,2), descalcificadas (EDTA al 10%) y procesadas histológicamente (HE y Picro-Sirius) para el análisis histológico. El análisis morfológico reveló la presencia de osteocitos y trabéculas en el tejido óseo neoformado cerca de los aloinjertos y la ausencia de células inflamatorias y alérgicas; los remanentes de CB se ubicaron principalmente en la periferia del tejido óseo y los remanentes de DBM se incorporaron más en el tejido. Se observaron células osteogenitoras alrededor del material restante. La densidad celular no se modificó en el tejido óseo recién formado con la aplicación de ambos aloinjertos en comparación con el tejido óseo maduro. La densidad de los colágenos de tipo I y III presentes en los osteoides intercalados con el resto de los materiales mostró una tendencia a aumentar en las muestras tratadas con DBM. Se concluyó que, debido a las características histológicas observadas, ambos injertos fueron biocompatibles, sin embargo, el hueso tratado con DBM presentó una mejor incorporación y una tendencia al aumento del contenido de colágeno en la región remanente de los aloinjertos.

Uso de la Fibrina Rica en Plaquetas Inyectable (i-PRF) en Defectos Infra Óseos en Terapia Periodontal no Quirúrgica. Reporte de Dos Casos / Use of Injectable Platelet-Rich Fibrin (i-PRF) in Infra Osseous Defects in Non-Surgical Periodontal Therapy. Report of Two Cases

RESUMEN: Entre los concentrados plaquetarios de segunda generación, ha suscitado creciente interés, el uso de fibrina rica en plaquetas y leucocitos inyectable (i-PRF); que se obtiene a partir de la centrifugación inmediata de sangre venosa del propio individuo, y que aporta concentraciones elevadas de factor de crecimiento vascular endotelial, factor de crecimiento transformante beta, y factor de crecimiento derivado de plaquetas, entre otras proteínas que inician y coordinan el proceso reparativo. Su nula citotoxicidad y consistencia líquida abren un nuevo campo de estudio y experimentación en el ámbito de la Cirugía Oral y de la Periodoncia, como sustancia para irrigar. El objetivo de este manuscrito fue reportar el uso del i-PRF como irrigador subgingival en el tratamiento periodontal convencional de defectos infra óseos con 6 meses de seguimiento. En ambos casos, se verificó un efecto positivo de irrigación, lo que abre el debate al uso de productos farmacéuticos tradicionales como la clorhexidina versus preparados autólogos sin efectos adversos reportados a la fecha.

ABSTRACT: Second generation platelet concentrates include the use of injectable platelet-rich fibrin (i-PRF), which has generated increasing interest because it is derived from immediate centrifugation of venous blood from the patients themselves. It provides high concentrations of vascular endothelial growth factor, transforming growth factor beta, and platelet-derived growth factor, among other proteins that initiate and coordinate the healing process. Its null cytotoxicity and liquid consistency has opened new research lines in the field of oral surgery and periodontics, as an irrigation substance. The aim of this manuscript was to report the use of i-PRF, as a subgingival irrigator in conventional periodontal treatment of infra osseous defects, with six months follow-up. In both cases, a positive effect of irrigation was confirmed. These findings, open the debate as regards the use of traditional pharmaceutical products (such as chlorhexidine), versus autonomous preparations without adverse effects reported to date.

Fibrin biopolymer as scaffold candidate to treat bone defects in rats

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.(AU)

The cortical matrix of femur in adult-aged Wistar rats is critically affected by maternal malnutrition during lactation period / La matriz cortical del fémur en ratas Wistar de edad adulta se ve críticamente afectada por la malnutrición materna durante el período de lactancia

Osteoporosis is associated with poor dietary habits. Malnutrition is characterized as a deficit on the intake of necessary nutrients that are essential for optimal health maintenance. It is known that malnutrition during the lactation period can affect the offspring. The present study aims to evaluate the chronic effects caused by maternal energy-protein restriction during lactation period in the offspring. At parturition, Wistar rat dams were divided in three groups: (1) Control group (C) - which received a 23 % protein diet without restrictions; (2) Protein-Energy restriction group (PER)- which received a 8 % protein diet; (3) Energy restriction group (ER) which received a 23 % protein diet in limited amounts, according to the ingestion of the second group. Each group had 12 pups. After weaning, all pups received free access to a 23 % protein diet until 180 days and then were euthanized. Their femur was excised, decalcified, histologically processed and analyzed under a microscope. The measurements of the osteon lacunae on the C, ER and PER groups were, respectively: 2.1 µm, 10.9 µm and 14.7 µm (p<0.05). A poor ingestion of proteins and calories during lactation period provoked critical and permanent changes on the bone matrix of the femur, which simulated osteoporosis.

La osteoporosis se asocia con malos hábitos alimenticios. La desnutrición se caracteriza como un déficit en la ingesta de los nutrientes necesarios que son esenciales para un mantenimiento óptimo de la salud. Se sabe que la malnutrición durante el período de lactancia puede afectar a la descendencia. El presente estudio tiene como objetivo evaluar los efectos crónicos causados por la restricción energética-proteína materna durante el período de lactancia en la descendencia. En el parto, las hijas de rata Wistar se dividieron en tres grupos: (1) grupo control (C) - que recibió una dieta con 23 % de proteína sin restricciones; (2) Grupo restricción de energía de proteína (PER) - que recibió una dieta con 8 % de proteína; (3) Grupo restricción de energía (ER) - que recibió una dieta de 23 % de proteína en cantidades limitadas, de acuerdo con la ingestión del segundo grupo. Cada grupo tenía 12 crías. Después del destete, todas las crías recibieron acceso libre a una dieta con 23 % de proteína hasta 180 días y luego fueron sacrificadas. Su fémur fue extirpado, descalcificado, procesado histológicamente y analizado bajo un microscopio. Las mediciones de las lagunas de osteón en los grupos C, ER y PER fueron, respectivamente: 2,1 mm, 10,9 mm y 14,7 mm (p <0,05). Una mala ingesta de proteínas y calorías durante el período de lactancia provocó cambios críticos y permanentes en la matriz ósea del fémur, que simulaba osteoporosis.

Demineralized bone matrix and calcium-phosphate cement in bone regeneration in rats

Abstract Purpose: To compare bone regeneration in critical-sized defects in rat calvarium using demineralized bone matrix and calcium phosphate cement. Methods: Thirty Wistar rats were divided into 3 groups of 10 animals each. Two defects of 5-mm were made in the parietal bones of each animal. Group I had calcium phosphate cement placed in the experimental defect, Group II had filled with demineralized bone matrix and Group III had with the combination of the matrix and cement in equal parts. All animals had one defect left unfilled to serve as controls. Five animals in each group were sacrificed at 4 and 8 weeks. Histomorphometric analysis was used to quantify the amount of new bone within the defects. Results: The results showed that demineralized bone matrix-treated defects had significantly more new bone at 4 weeks compared to calcium phosphate cement-treated defects (p=0.03) and also had significantly more new bone at 8 weeks compared to unfilled defects (p=0.04). Conclusions: The demineralized bone matrix was superior to calcium phosphate cement in bone regeneration. It seems that calcium phosphate cement acted by inhibiting the osteogenesis when associated with a demineralized bone matrix and this combination should not be recommended.

Oral implant osseointegration model in C57Bl/6 mice: microtomographic, histological, histomorphometric and molecular characterization

Abstract Despite the successful clinical application of titanium (Ti) as a biomaterial, the exact cellular and molecular mechanisms responsible for Ti osseointegration remains unclear, especially because of the limited methodological tools available in this field. Objective: In this study, we present a microscopic and molecular characterization of an oral implant osseointegration model using C57Bl/6 mice. Material and Methods: Forty-eight male wild-type mice received a Ti implant on the edentulous alveolar crest and the peri-implant sites were evaluated through microscopic (μCT, histological and birefringence) and molecular (RealTimePCRarray) analysis in different points in time after surgery (3, 7, 14 and 21 days). Results: The early stages of osseointegration were marked by an increased expression of growth factors and MSC markers. Subsequently, a provisional granulation tissue was formed, with high expression of VEGFb and earlier osteogenic markers (BMPs, ALP and Runx2). The immune/inflammatory phase was evidenced by an increased density of inflammatory cells, and high expression of cytokines (TNF, IL6, IL1) chemokines (CXCL3, CCL2, CCL5 and CXC3CL1) and chemokine receptors (CCR2 and CCR5). Also, iNOS expression remained low, while ARG1 was upregulated, indicating predominance of a M2-type response. At later points in time, the bone matrix density and volume were increased, in agreement with a high expression of Col1a1 and Col21a2. The remodelling process was marked by peaks of MMPs, RANKL and OPG expression at 14 days, and an increased density of osteoclasts. At 21 days, intimate Ti/bone contact was observed, with expression of final osteoblast differentiation markers (PHEX, SOST), as well as red spectrum collagen fibers. Conclusions: This study demonstrated a unique molecular view of oral osseointegration kinetics in C57Bl/6 mice, evidencing potential elements responsible for orchestrating cell migration, proliferation, ECM deposition and maturation, angiogenesis, bone formation and remodeling at the bone-implant interface in parallel with a novel microscopic analysis.

Baja masa ósea y osteoporosis en pacientes con lupus eritematoso sistémico / Low bone mass and osteoporosis in patients with systemic lupus erythematosus

RESUMEN Introducción: El lupus eritematoso sistémico es una enfermedad autoinmune, multisistémica y crónica, de etiología desconocida, en la cual la frecuencia de alteraciones en la densidad mineral ósea varía entre 25-74%; si bien su diagnóstico no está estandarizado. Objetivo: Describir las alteraciones densitométricas en pacientes con lupus eritematoso sistémico, así como las características clínicas y demográficas en 2 centros de referencia del noroccidente colombiano. Materiales y métodos: Estudio transversal realizado entre enero de 2013 y diciembre de 2014. Variables incluidas: demográficas, estado de menopausia, consumo de tabaco y alcohol, autoanticuerpos, compromiso orgánico, medicamentos e índices de actividad y cronicidad (SLEDAI, SLICC). Alteraciones densitométricas definidas según la Organización Mundial de la Salud. Análisis estadístico: Frecuencias absolutas y relativas para variables cualitativas; mediana con rango intercuartílico (RIQ) para variables cuantitativas. Resultados: De 302 pacientes evaluados, 65 cumplieron criterios de elegibilidad. Treinta y uno por ciento de las pacientes premenopáusicas tenían baja masa ósea para la edad; un 50% de las mujeres posmenopáusicas tenían osteoporosis y un 27% baja masa ósea. Número de pacientes con alteraciones densitométricas según factores asociados: fracturas 4, consumo de alcohol 2, fumadores activos 3, anticuerpos anti-Ro 8, afección neurológica 7, falla renal crónica 4. Uso de prednisolona: 53,8%; mediana de dosis diaria: 10 mg (RIQ5-52). Medianas de SLEDAI y SLICC: 0 (RIQ= 0-4) y 0,5 (RIQ= 0-1,75), respectivamente. Conclusiones: Se encontraron pocas densitometrías óseas en pacientes con lupus; la frecuencia de las alteraciones minerales óseas fue independiente del estado de menopausia. La mediana de dosis de prednisolona fue alta, en sujetos en remisión y sin daño orgánico.

ABSTRACT Introduction: Systemic lupus erythematosus is a chronic, autoimmune, multisystem disease of unknown aetiology, and in which the frequency of alterations in bone mineral density varies between 25% and 74%, although its diagnosis is not standardised. Objective: To describe the densitometric changes in systemic lupus erythematosus patients, as well as the clinical and demographic characteristics from two reference centres northwestern Colombia. Materials and methods: A cross-sectional study was conducted between January 2013 and December 2014. The data collected included the demographic variables, menopausal status, use of tobacco and alcohol, autoantibodies, organ involvement, medications, as well as the activity and chronicity indices (SLEDAI, SLICC). Densitometric changes were defined according to World Health Organisation criteria. Statistical analyses: Absolute and relative frequencies were calculated for qualitative variables, and medians with interquartile range (IQR) for quantitative variables. Results: Of the total 302 patients evaluated, 65 met eligibility criteria. Thirty-one percent of premenopausal patients had low bone mass for age was observed in 31% of pre-menopausal women, with 50% of post-menopausal women showing osteoporosis, and 27% low bone mass. The number of patients with densitometric alterations according to associated factors was, fractures 4, alcohol consumption 2, active smokers 3, anti-Ro antibodies 8, neurological involvement 7, and chronic renal failure 4. Prednisone was used in 53.8%, with a median daily dose of 10mg (IQR5-52). The median SLEDAI and SLICC was 0 (IQR = 0-4) and 0.5 (IQR = 01.75), respectively. Conclusions: Few bone densitometry results were found in patients with systemic lupus erythematosus. The frequency of mineral bone disorders was independent of menopausal status. The median dose of prednisone was high in subjects in remission, and without organ damage.

Marcadores de remodelamiento óseo en pacientes con enfermedad periodontal / Bone remodeling biomarkers in patients with periodontal disease

La Fosfatasa Alcalina Ósea (FAO) es una isoforma de la Fosfatasa Alcalina (FAL). La medición de su actividad en saliva es una medida indirecta del proceso de formación ósea, más sensible y específica que la FAL. La catepsina K es la principal colagenasa del proceso de resorción ósea, es capaz de degradar al colágeno tipo I en varios sitios dando lugar a pequeños péptidos N- y C- terminales. El telopéptido C-terminal (CTx) es el marcador más sensible y específico en el aumento de la resorción ósea, ya que el colágeno tipo I constituye más del 90 por ciento de la matriz orgánica del hueso...

Simvastatin and biphasic calcium phosphate affects bone formation in critical-sized rat calvarial defects

ABSTRACT PURPOSE: To investigate the effects of locally applied simvastatin plus biphasic calcium phosphate (BoneCeramic(r)) or collagen sponge on bone formation in critical-sized bone defects. METHODS: Thirty defects of 5mm in diameter were created bilaterally with a trephine bur in the calvariae of fifteen Wistar rats. The defects were divided into five groups: group 1 - control, no treatment; group 2 (BoneCeramic(r)); group 3 (BoneCeramic(r) + 0.1mg simvastatin); group 4 (collagen sponge); and group 5 (collagen sponge + 0.1mg simvastatin). After eight weeks the animals were euthanized and their calvariae were histologically processed. Hematoxylin and eosin-stained sections were subjected to histological and histomorphometrical analyses. The area of newly formed bone was calculated and compared between groups. RESULTS: The greater amount of a bone-like tissue was formed around the carrier in group 3 (BoneCeramic(r) + 0.1mg simvastatin) followed by group 2 (BoneCeramic(r)), and almost no bone was formed in the other groups. Group 3 was significantly different compared to group 2, and both groups were significantly different compared to the other groups. CONCLUSION: Simvastatin combined with BoneCeramic(r) induced significantly greater amounts of newly formed bone and has great potential for the healing of bone defects.

Respuesta tisular en defectos tratados con matriz ósea de origen bovino o humano / Tissue response in treated defects with bovine or human bone matrix

El objetivo de esta investigación fue comparar la respuesta tisular en defectos tratados con matriz óseo de origen bovino y humano. Se realizó un estudio descriptivo con 12 conejos en los cuales se confeccionaron dos defectos en la calota craneana de acuerdo a procesos convencionales. Cada defecto fue aleatoriamente rellenado con matriz ósea bovina o con matriz ósea humana; se realizaron evaluaciones histológicas a las 7 y 15 semanas de realizada la cirugía (6 animales en cada grupo). A las 7 semanas se identificó un leve infiltrado inflamatorio y claras diferencias entre el hueso periférico y el sitio injertado, mientras que a las 15 semanas se observo la persistencia de algunas partículas injertadas y la presencia de hueso nuevo formado en el defecto; no se logró identificar diferencias en la secuencia de reparación o retrasos en la misma con ninguno de los dos materiales. Se concluye que ambos materiales son útiles en la regeneración ósea en el presente modelo experimental.

The aim of this research was to compare the tissue response in treated defects with bone matrix with bovine or human origin. Was realized a descriptive study with 12 rabbits where was executed two defects in the skull in relation to conventional techniques. Randomized defects were used to put bone matrix with bovine or human origin; histological exam was realized in the week number 7 and 15 with 6 animals each. At 7 weeks was observed a limited inflammatory infiltrate with clear differences between the peripheral bone and the filled bone and in the 15 weeks of analysis was observed the presence of some particulate of the bone graft beside a new bone into the defect; was not observed any differences in the sequence of repair or delayed in the bovine or human material. It´s concluded that both materials are useful in bone regeneration for this experimental model.

Expressão da Osteopontina após utilização de matriz dentinária humana desmineralizada em alvéolos de ratos: análise imunohistoquímica / Osteopontin expression after use of demineralized human dentin matrix in rats alveoli: immunohistochemistry analysis

Apesar de sua capacidade de reparo, o tecido ósseo pode ser submetido a alguns tipos de fraturas, cirurgias ou patologias que podem levar a grandes defeitos ósseos. As principais estratégias de tratamento de defeitos ósseos são baseados em osteoindução ou osteocondução. Matriz dentinária desmineralizada humana (MDDH) é uma alternativa biocompatível para preencher defeitos ósseos, melhorando a qualidade e quantidade de osso produzido. 24 Ratos Wistar foram selecionados, submetidos à extração de ambos os segundos molares superiores (direito e esquerdo). Os alvéolos foram separados em dois grupos: controle (direita) preenchido com coágulo sanguíneo e experimental (esquerda) preenchido com MDDH. Os animais foram sacrificados aos 5, 10 e 21 dias. Foram realizadas análises histológicas, histomorfométricas (análise de variância - ANOVA e teste de Tukey) e imunohistoquímica para osteopontina (OPN) como indicador de osteogênese. Aos 5 dias MDDH foi incorporada pelas novas trabéculas ósseas. Aos 10 dias observou-se organização do tecido conjuntivo e trabéculas no grupo experimental. Detectou-se coloração intensa para OPN em área adjacente à MDDH no grupo experimental. Aos 21 dias no grupo experimental verificou-se trabéculas maduras. Houve diferença estatísticamente significatva (p <0,05). Maior número de trabéculas em grupos experimentais que nos grupos controle em todos os períodos de análise. MDDH implantadas em alvéolos de ratos, induz a aceleração da osteogênese. Presença OPN observada mais intensamente aos 10 dias próximo à MDDH

BACKGROUND - Despite its good capacity for regeneration, bone tissue subjected to some types of fractures or surgery that can lead to large bone defects. The major bone defects treatment strategies are based in osteoinduction or osteoconduction. Demineralized human dentin matrix (DHDM) is a biocompatible alternative to fill bone defect, improving the quantity and quality of bone produced. METHODS - Wistar rats were selected, submitted to the extraction of both second molars (right and left). Alveoli were separated into two groups: control (right) filled with blood clot and experimental (left) filled with DHDM. Animals were sacrificed at 5, 10 and 21 days. Histological and histoquantitative analyzes (analysis of variance - ANOVA, and Tukey's test) were performed and immunostaining for osteopontin (OPN) as osteogenesis indicator. RESULTS - 5 days - DHDM incorporated by new trabeculae. 10 days - connective tissue organization and new trabeculae in the experimental group. Intense staining for OPN close to DHDM in the experimental group. 21 days - experimental group showing mature trabeculae. Statistical difference observed (p<0.05). Higher number of trabeculae in experimental groups in all periods of analysis. CONCLUSIONS - DHDM implanted in alveoli induces the acceleration of osteogenesis. Presence of OPN observed more intensely at 10 days close to DHDM

Avaliação das citocinas TNF-α, RANKL e OPG e do número de osteoclastos no reparo de defeito ósseo em calvária de ratos diabéticos tratados com matriz óssea desmineralizada / Evaluation of cytokines TNF-α, RANKL and OPG and the number of osteoclasts on repair of bone defects in skulls of diabetic rats treated with demineralized bone matrix

Neste trabalho, foi avaliado a participação dos osteoclastos bem como a ação das citocinas RANKL, OPG e TNF-α durante a formação e remodelação óssea em defeitos ósseos de tamanho crítico em ratos normoglicêmicos e diabéticos tratados ou não com a MAOD. Para isso, foram utilizados 250 ratos machos Wistar. Trinta ratos foram utilizados para coleta dos fêmures e tíbias, os quais foram processados para obtenção da MAOD. Os demais 220 ratos foram divididos em Grupo Não Diabétido (CTL, n=110) e Grupo Diabético (DIAB, n= 110) induzido pela aplicação de uma dose única de 47 mg/Kg de massa corporal de estreptozotocina. Um defeito transósseo de 8 mm de diâmetro foi realizado nos ossos parietais dos ratos, sendo que, nos subgrupos CTL MAOD e DIAB MAOD, os defeitos foram preenchidos com MAOD e nos grupos CTL COAG e DIAB COAG apenas com coágulo sanguíneo. Após 0, 7, 14, 21 e 42 dias, as calotas cranianas foram coletadas para determinação da densidade de volume, número de osteoclastos/mm2 na área do defeito, quantificação por imunoistoquimica e expressão do RNAm para as proteínas RANKL, OPG e TNF-α. Os resultados para volume do tecido ósseo neoformado foi maior nos grupos CTL COAG e CTL MAOD, bem como no grupo DIAB MAOD quando comparado com DIAB COAG (CTL MAOD > CTL COAG e DIAB MAOD > DIAB COAG). O número de osteoclastos nos grupos CTL aumentaram significantemente (3,69 osteoclasto/mm2), enquanto que nos grupos MAOD aumentaram gradualmente até os 42 dias (2,8 osteoclasto/mm2). Os resultados para imunomarcação mostraram que a MAOD promove 1,28 vezes maior expressão de OPG, bem como de TNF-α tanto no grupo CTL (1,59 vezes) como no DIAB (1,76 vezes). Os resultados para expressão do RNAm para OPG mostrou que a média dos valores do grupo COAG comparado com a do grupo MAOD foi 1,91 vezes maior no grupo COAG. Já os valores para expressão de RANKL permaneceram constantes no grupo DIAB MAOD, com aumento significativo de 2,57 vezes aos 42 dias, sendo 4,3 vezes maior, quando comparado com a média dos outros grupos no mesmo período. Conclui-se que nos animais normoglicemicos, o tratamento com a MAOD aumenta a expressão de OPG, RANKL e TNF-α, assim como a atividade osteoclástica, promovendo reabsorção da MAOD e formação de tecido ósseo, enquanto que nos animais diabéticos, a atividade osteoclástica foi reduzida, sem alteração nos níveis de OPG e RANKL, reduzindo a reabsorção da MAOD e consequentemente da formação óssea.(AU)

Participation of osteoclasts was evaluated in reabsorption process of demineralized allogenic bone matrix (DABM) as well as the activity of cytokines RANKL, OPG and TNF- α during formation and bone remodeling in critial size defect of normoglycemic and diabetic rats treated or not with DABM. Therefore, 250 male Wistar rats were used. Thirty rats had femurs and tibias collected and processed to obtain DABM. 220 rats were divided into control group (CTL, n=110) and diabetic group (DIAB, n= 110) injected by a single dose of 47 mg/Kg of body weight streptozotocin. Were made 8mm bone defect on skulls of rats, in subgroups CTL DABM and DIAB DABM, defects were filled with DABM and subgroups CTL CLOT and DIAB CLOT were filled with blood clot. After 0, 7, 14, 21 and 42 days, the skulls were collected to determine the volume density, number of osteoclasts/mm2 into defects area, quantification by immunohistochemistry and RNAm expression of RANKL, OPG and TNF-α cytokines. The results of volume density of newly formed bone was higher in CTL CLOT and CTL DABM, as well as in DIAB DABM compared to DIAB CLOT (CTL DABM > CTL CLOT and DIAB DABM > DIAB CLOT). The number of osteoclasts in CTL groups increased to 3,69 osteoclasts/mm2, while in subgroups treated with DABM gradually increased up until 42 days (2,8 osteoclasts/mm2). Immunohistochemistry showed that DABM promotes an increase of 1.28-fold of OPG expression, as well as TNF-a expression in CTL group (1.59-fold) and DIAB group (1.76-fold). The results of RNAm expression of OPG showed that the average values of the CLOT subgroup compared to the average values of DABM subgroup was 1.91- fold higher in CLOT subgroup. The values of RANKL RNAm expression increase 2.57-fold at 42 days, being 4.3-fold higher than the average os the other groups in the same period. In conclusion, in the normoglicemic animals (CTL group), the treatment with DABM increase the expression of OPG, RANKL and TNF-α as the activity of osteoclasts, leading to DABM resorption and bone tissue formation, while in diabetic animals, the osteoclast activity was reduced, without changes in the leves of OPG and RANKL, decreasing DABM resorption and bone formation.(AU)

Estudio clínico e histológico de aloinjerto de hueso liofilizado en alvéolos pos extracción: presentación de caso clínico / Clinical and histological study of bone freeze drying allograft in postextraction sockets: report of a clinical case

Objetivos: evaluar las respuestas clínicas e histológicas y determinar la calidad del hueso obtenido por medio del aloinjerto utilizado en un alvéolo posextracción en el que se realizó una técnica de preservación del volumen alveolar, a fin de colocar implantes. Caso clínico: una paciente de 47 años recibió un tratamiento de preservación del volumen alveolar posextracción mediante aloinjerto de hueso liofilizado (matriz ósea UNC en polvo) contenido por una lámina ósea cortical (matriz ósea UNC en membrana). A los 120 días, se tomó biopsia y se colocaron implantes. La muestra se observó con microscopía óptica. Conclusión: histológicamente, se identificaron restos de partículas y de lámina ósea, e intensos fenómenos de angiogénesis y neoformación ósea. La observación clínica permitió visualizar los márgenes nítidos del reborde y verificar la conservación del volumen ósea en el lugar en el que se realizó la fijación primaria de los implantes. La técnica de preservación con los biomateriales citados permite la colocación del implante en una posición adecuada, con resultados funcionales y estéticos.

Histomorphometry of the organic matrix of the femur in ovariectomized rats treated with sodium alendronate / Histomorfometria da matriz orgânica do fêmur de ratas ovariectomizadas tratadas com alendronato de sódio

To evaluate the effect of two different concentrations of sodium alendronate on the quantity of organic matrix in the femur of rats with estrogen suppression caused by ovariectomy. METHODS: Sixty-days-old Wistar rats (Rattus norvegicus) were subjected to bilateral laparotomy to remove the ovaries. The animals were divided into a control group, in which they only underwent laparotomy; an ovariectomized group (OVX); an ovariectomized group treated with 1 mg/kg of alendronate (OVX 1 mg); and an ovariectomized group treated with 2 mg/kg of alendronate (OVX 2 mg). The rats received alendronate twice a week for 90 days. The left femur was then removed, fixed and processed for embedding in paraffin. Semi-serial sections stained with hematoxylin and eosin were used to determine the area occupied by organic bone matrix, by means of image analysis software. The animals' weights were obtained at the beginning and end of the experiment. RESULTS: The ovariectomized animals and those treated with 1 mg/kg of alendronate presented significant increases in body weight (p < 0.05), in comparison with the control group. Histomorphometric analysis revealed that in the animals treated with 2 mg/kg of alendronate, the area (µm2) occupied by organic matrix (1,81,900 ± 18,130) was similar (p > 0.05) to that of the non-ovariectomized control animals (2,04,800 ± 9590), which indicates that this medication had a preventive effect with regard to bone mass loss. CONCLUSION: The higher concentration of the medication, administered twice a week for 90 days, was more effective than the dose of 1 mg/kg over the same period...

Avaliar a efeito de duas concentrações diferentes de alendronato de sódio (ALN) sobre a quantidade de matriz orgânica no fêmur de ratas com supressão estrogênica provocada por ovariectomia. MÉTODOS: ratas Wistar (Rattus norvegicus) com 60 dias foram submetidas a laparotomia bilateral para remoção dos ovários. Os animais foram divididos em grupo controle, no qual os animais foram apenas laparotomizados; grupo ovariectomizado (OVX); grupo ovariectomizado tratado com 1 mg/kg de ALN (OVX 1 mg); e grupo ovariectomizado tratado com 2 mg/kg de ALN (OVX 2 mg). Receberam ALN duas vezes por semana durante 90 dias. O fêmur esquerdo foi coletado, fixado e processado para inclusão em parafina. Cortes semisseriados corados com H&E foram usados para a obtenção, com um software de análise de imagens, da área ocupada por matriz óssea orgânica. O peso dos animais foi obtido no inicio e no fim do experimento. RESULTADOS: os animais ovariectomizados e aqueles tratados com 1 mg/kg de ALN tiveram um aumento significativo (p < 0,05) no peso corporal quando comparados com o grupo controle. A análise histomorfométrica revelou que nos animais tratados com 2 mg/kg de ALN a área (µm2) ocupada por matriz orgânica (181.900 ± 18.130) foi semelhante (p > 0,05) àquela dos animais controle não ovariectomizados (204.800 ± 9.590), o que indica um efeito preventivo desse medicamento sobre a perda de massa óssea. CONCLUSÃO: a maior concentração do medicamento administrado duas vezes por semana por 90 dias foi mais eficaz do que a dose de 1 mg/kg no mesmo período...

Diagnosis, classification and treatment of gestational trophoblastic neoplasia / Diagnóstico, classificação e tratamento da neoplasia trofoblástica gestacional

Gestational trophoblastic neoplasia (GTN) is the term to describe a set of malignant placental diseases, including invasive mole, choriocarcinoma, placental site trophoblastic tumor and epithelioid trophoblastic tumor. Both invasive mole and choriocarcinoma respond well to chemotherapy, and cure rates are greater than 90%. Since the advent of chemotherapy, low-risk GTN has been treated with a single agent, usually methotrexate or actinomycin D. Cases of high-risk GTN, however, should be treated with multiagent chemotherapy, and the regimen usually selected is EMA-CO, which combines etoposide, methotrexate, actinomycin D, cyclophosphamide and vincristine. This study reviews the literature about GTN to discuss current knowledge about its diagnosis and treatment.

Neoplasia trofoblástica gestacional (NTG) é o termo que descreve o conjunto de anomalias malignas da placenta, incluindo a mola invasora, coriocarcinoma, tumor trofoblástico do sítio placentário e tumor trofoblástico epitelióide. Ambos a mola invasora e o coriocarcinoma respondem bem à quimioterapia, com taxas de cura superiores a 90%. Desde o advento da quimioterapia, NTG de baixo risco tem sido tratada com monoquimioterapia, pelo geral methotrexate ou actinomicina-D. Casos de NTG de alto risco, contudo, devem ser tratados com poliquimioterapia, e o regime usualmente escolhido é o EMA-CO que combina etoposide, methotrexate, actinomicina-D, ciclofosfamida e vincristina. Esse estudo revê a literatura sobre NTG a fim de discutir os conhecimentos atuais sobre seu diagnóstico e tratamento.

Injerto de matriz ósea en partículas asociado a plasma rico en plaquetas (PRP): estudio experimental / Bone matrix and platelet rich plasma (PRP) grafting: an experimental study

Los injertos o sustitutos óseos se utilizan con el fin de solucionar situaciones de déficit en el hueso, aunque aún existen controversias sobre los mecanismos de osteoinducción que estos rellenos promueven dentro de los tejidos. La combinación con plasma rico en plaquetas (PRP) podría aumentar la capacidad de reparación ósea. Objetivo: estudiar el efecto biológico (biocompatibilidad y osteoinducción) de la matriz ósea de la Universidad Nacional de Córdoba (MO-UNC) y el plasma rico en plaquetas (PRP). Métodos: se utilizaron 30 ratas Wistar anestesiadas con ketamina-xilazina. En 4 sitios del tejido celular subcutáneo de la región dorsal se implantaron tubos de silicona conteniendo los materiales experimentales: MO (partículas de MO-UNC), PRP, MO+PRP (partículas de MO embebidas en PRP), GC (Controles, sin relleno). Se tomaron biopsias de los sitios de implante a los 30 y 60 días poscirugía y se obtuvieron cortes histológicos para analizar la biocompatibilidad y la neoformación ósea alrededor de los materiales implantados. Resultados: si bien en ninguno de los grupos se identificó tejido óseo neoformado, en el grupo MO+PRP a 30 días se constató un aumento del número de cpailares neoformados alrededor de las partículas. A los 60 días, las partículas de MO-UNC mostraron áreas lacunares compatibles con actividad resorsiva. En este estudio, las partículas de MO-UNC se comportaron como injertos biocompatibles, siendo progresivamente resorbidas en el organismo de los animales. Se confirmó un efecto angiogénico del PRP...