Evolution of Periodontal Disease: Immune Response and RANK/RANKL/OPG System

Abstract The aim of this study was to evaluate markers of bone loss and immune response present in evolution of periodontal disease. One hundred and two Wistar rats were divided into three animals groups: PD0, without ligation and PD15 days and PD60 days, submitted to ligation placement with a sterile 3-0 silk cord in the cervical region of the upper first molar on both sides. Samples were obtained from the gingival tissue for histomorphometric analysis, immunohistochemical analysis of RANK, RANKL, OPG, characterization of the inflammatory infiltrate, quantification of nitric oxide, MCP-1, RANTES, IP10 chemokines, and expression of the TGF-b1, VEG, and bFGF. The number of inflammatory cells in gingival tissue was higher in PD60 samples. The collagen content and the area occupied by birefringent collagen fibers were lower for PD60. Differential leukocyte counting showed that there was a significantly higher polymorphonuclear influx in group PD15, while PD60 showed a greater number of lymphocytes. PD60 showed higher RANTES, IP-10, MCP-1 gene transcripts, as well as a higher nitric oxide concentration. Clinical evaluation revealed that the PD60 group presented an increase in furcal area. In conclusion, in this animal model the increase of RANK/RANKL and HGF markers is related to a specific immune response, and probably contributed to the evolution of periodontal disease. Investigating the effect of these biomarkers can help in targeted therapy for bone resorption, since blocking these can inhibit bone loss.

Resumo Este estudo avaliou marcadores de perda óssea e da resposta imune presentes na evolução da doença periodontal. Cento e dois ratos Wistar foram divididos em três grupos de animais: PD0, sem ligadura e PD15 dias e PD60 dias, submetidos a colocação de ligadura com um fio de seda estéril 3-0 na região cervical do primeiro molar superior em ambos os lados. Foram obtidas amostras de tecido gengival para análise histomorfométrica, análises imunohistoquímicas de RANK, RANKL, OPG, caracterização do infiltrado inflamatório, quantificação de óxido nítrico, expressão de quimiocinas MCP-1, RANTES, IP10 e do TGF-b1, VEGF e bFGF . O número de células inflamatórias no tecido gengival foi maior nas amostras PD60. O teor de colágeno na área ocupada pelas fibras de colágeno birrefringentes foram menores para PD60. A contagem diferencial de leucócitos mostrou que houve um influxo polimorfonuclear significativamente maior no grupo PD15, enquanto que PD60 mostrou número maior de linfócitos. PD60 apresentou transcritos de genes RANTES, IP-10, MCP-1 mais elevados, bem como uma maior concentração de óxido nítrico. A avaliação clínica revelou que o grupo PD60 apresentou aumento da área óssea exposta na região da furca. Em conclusão, neste modelo animal o aumento dos marcadores RANK/RANKL e HGF está relacionado a uma resposta imunológica específica e provavelmente contribuiu para a evolução da doença periodontal. Investigar o efeito destes biomarcadores pode ajudar na terapia dirigida para a reabsorção óssea, uma vez que bloquear estes pode inibir a perda óssea.

Effects of the application of Aloe vera (L. ) and microcurrent on the healing of wounds surgically induced in Wistar rats / Efeitos da aplicação de Aloe vera (L. ) e microcorrente no reparo de lesões cirúrgicas induzidas em ratos Wistar

PURPOSE: To investigate the effects of topical application of an Aloe vera gel combined or not with microcurrent application on the healing of skin wounds surgically induced in Wistar rats. METHODS: The animals were randomly divided into the following groups: control group, animals topically treated with Aloe vera, animals treated with a microcurrent, and animals receiving topical application of Aloe vera combined with microcurrent application. RESULTS: The results indicated differences in wound healing between the various treatments when compared to the control group. Tissue hyperplasia was lower in the control group compared to the other treated groups. Accelerated wound healing was observed in the group treated with Aloe vera compared to control. Animals submitted to microcurrent application only and the group treated with microcurrent plus Aloe vera presented an earlier onset of the proliferative phase compared to the control group and animals treated with Aloe vera gel alone. Morphometric data confirmed the structural findings. CONCLUSION: Simultaneous application of Aloe vera gel and microcurrent is an excellent choice for the treatment of open wounds thus indicating a synergistic action of these two applications.

OBJETIVO: Investigar os efeitos da aplicação tópica do gel de Aloe vera, combinada ou não com a aplicação de microcorrente no reparo de lesões cutâneas induzidas cirurgicamente em ratos Wistar. MÉTODOS: Os animais foram distribuídos aleatoriamente em: grupo controle, tratado topicamente com gel in natura de Aloe vera, tratado com microcorrente e tratado com aplicação tópica de Aloe vera associada à microcorrente. RESULTADOS: Os resultados do presente trabalho indicaram que o reparo tecidual ocorreu de forma diferenciada nos vários tratamentos empregados quando comparados ao grupo controle. A hiperplasia tecidual no grupo controle foi menor que a observada nos demais grupos tratados. No grupo tratado com aplicação de Aloe vera o processo de reparo foi acelerado em relação ao controle. Os animais do grupo tratado somente com microcorrente e do grupo tratado com microcorrente associada à Aloe vera apresentaram uma fase proliferativa mais precoce quando comparados com o grupo controle e tratado somente com Aloe vera. Os dados morfométricos confirmaram os achados estruturais. CONCLUSÃO: A aplicação simultânea do gel de Aloe vera e microcorrente é uma excelente escolha para o tratamento de feridas abertas indicando uma ação sinérgica dessas duas aplicações.

Muscle fibre types and connective tissue morphometry in frontal muscle of Norfolk rabbits (Oryctolagus cuniculus) / Morfometría de los tipos de fibra muscular y del tejido conectivo en músculo frontal de conejos Norfolk (Oryctolagus cuniculus)

The frontal muscle is formed by a complex of contractile elements which compose the set of facial muscles responsible for the expression of emotions. In view of its functional characteristics the frontal muscle consists of a mixture of high (type I) and low oxidative (type II) muscle fibres. The objective of the present study was to determine the area, diameter, and relative volume occupied by each fibre type in frontal muscles of Norfolk rabbits using nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) histochemistry combined with morphometry. In addition, the connective tissue area (endomysium) and the number of blood vessels per fibre were evaluated. Female rabbits ranging in age from 6 to 8 months and weighing 2.8 to 3.1 kg were used. Four quadrants of samples from 12 animals were analysed. Type IIB fibres occupied the largest area compared to the other fibre types. The fibre diameter and relative volume were similar among the different fibre types identified by NADH-TR staining. No significant difference in the number of vessels per fibre was observed between the different fibre types. The endomysial area occupied the smallest area among the parameters analyzed. These findings demonstrated the intense activity of this muscle in the facial architecture of the animal. However, the low oxidative type II fibres predomination indicates more prone to muscle fatigue. The present findings may contribute to the study of myopathies involving this muscle.

El músculo frontal está formado por un complejo de elementos contráctiles que componen el conjunto de músculos faciales responsables de la expresión de emociones. A la vista de las características funcionales, el músculo frontal está constituido de una mezcla de fibras musculares de alto (tipo I) y bajo nivel de oxidación (tipo II). El objetivo del presente estudio fue determinar área, diámetro y volumen relativo ocupado por cada tipo de fibra en los músculos frontales de conejos Norfolk utilizando histoquímica para nicotinamide adenina dinucleotide tetrazolium reductasa (NADH-TR), combinado con su morfología. Además, fueron evaluados la zona de tejido conectivo (endomisio) y el número de vasos sanguíneos por fibras. Fueron utilizados conejos hembras, de edades comprendidas entre los 6 a 8 meses y con un peso de 2,8 a 3,1 kg. Se analizaron cuatro cuadrantes de las muestras de 12 animales. Las fibras tipo IIB ocuparon la mayor superficie, en comparación con los otros tipos de fibras. Los diámetros y volúmenes relativos de las fibras fueron similares entre los diferentes tipos identificados por NADH-TR. No se observaron diferencias significativas en el número de vasos por fibra, entre los diferentes tipos de fibras. El área ocupada por el endomisio fue la superficie más pequeña entre los parámetros analizados. Estos resultados demostraron la intensa actividad de este músculo en la arquitectura facial del animal. Sin embargo, el predominio de las fibras tipo II, de baja oxidación, indica más propensión a la fatiga muscular. El presente hallazgo pueden contribuir al estudio de las miopatías con la participación de este músculo.

Viability of nerve grafts preseved in different storage medium

We compared the structural features of nerve segments stored in two different solutions previous and after autologous transplantation. Male Wistar rats were divided into groups to obtain normal tibial nerves, freshly transplanted nerves, and nerves stored in Wisconsin/Belzer or Collins solution for 24 or 72 h at 4ºC and transplanted. Stored and transplanted segments were processed for morphologic and morphometric analysis. The cross-sections of segments stored in Wisconsin/Belzer and Collins solution presented aspects similar to that of normal nerves. The density of large-caliber myelinated axons was higher in grafts stored in Wisconsin/Belzer solution than in those preserved in Collins solution. But the density of myelinated axons regenerated through these grafts was around 80% to that registered in the fresh and Wisconsin/Belzer preserved grafts. Moreover, no significant differences in the morphometric parameters were observed between groups. Our data confirm the efficacy of Wisconsin/Belzer to nerve graft preservation and stimulate more detailed physiological, biochemical and molecular studies to rationalize the employment of less expensive and handful storage solutions for short term preservation of peripheral nerve grafts.

Efeitos de diferentes intensidades de microcorrente no reparo ósseo em ratos Wistar / Effects of different microcurrent intensities in Wistar rats bone repair

Objetivo: Comparar a ação de diferentes intensidades de microcorrente no reparo de fratura experimental em tíbias de ratos Wistar. Métodos: Foram utilizados 20 ratos Wistar (Rattus norvegicus) com peso médio de 300g. Os animais devidamente anestesiados foram submetidos à fratura experimental da tíbia direita e divididos em grupo controle (C); grupos I, II e III submetidos a uma sessão diária de microcorrente com intensidade de 2j.A/3min, 2 A/5min e 5 A/3min, respectivamente, durante 28 dias. Um animal de cada grupo foi sacrificado a cada semana para análise histopatológica. Resultados: Nos grupos I e II, os fenômenos de reparo apresentaram a mesma seqüência temporal detectada no controle, mas com aumento no volume de tecido ósseo neoformado entre a terceira e quarta semanas. O grupo III apresentou aumento no volume tecidual e na velocidade de reparo, pois na terceira semana pôde-se observar a consolidação entre as extremidades ósseas. Conclusão: O efeito do estímulo diário com 5 A durante três minutos apresentou melhores resultados no reparo ósseo em fraturas fechadas e não imobilizadas de ratos quando comparados com os outros grupos experimentais.

Physicochemical and structural analysis of three regions of the deep digital flexor tendon of pigs

Few studies have discussed the relationship between the molecular organization and the physicochemical and biomechanical properties of pig tendons. In this work, we examined the extracellular matrix of the deep digital flexor tendon of pigs, which was subjected to tensional (proximal region) and compressive (distal and terminal regions) forces. The three regions of the tendon were used for swelling tests and their glycosaminoglycan content was determined. Longitudinal sections of the tendon were stained and observed using polarized light microscopy. The distal and terminal regions were swole more in water than the proximal region. After staining with toluidine blue the metachromasy was more intense in the distal and terminal regions, indicating an accumulation of proteoglycans in these regions. Analysis of the glycosaminoglycans by agarose gel electrophoresis showed that dermatan sulfate was present in all regions, whereas chondroitin sulfate occurred only in the regions of compression. The shape of the fibroblasts changed along the tendon: rounded cells occurred in regions under compression, while in the region under tension, elongated cells predominated. The organization and distribution of the collagen bundles were different for each region. Birefringence analysis revealed a more regular crimp pattern in the region under tension than in the regions under compressive forces. The elastic fibers also showed a different distribution in each region. These results indicate that the regional differences in the structure and composition of the deep digital flexor tendon of pigs are related to the biomechanical properties of the tendon.

Ultrastructural characteristics of tensional regions in tendons from rats of different ages

The calcaneal tendon and the deep digital flexor tendon are collagen-rich structures which are adapted to resist tensile stress. Since during aging tendons undergo modifications in their mechanical properties and in collagen aggregation, an understanding of the structural changes involved is important. In this work, the structural organization of the tensile region of the calcaneal and deep difital flexor tendons was studied in male Wistar rats 30, 180 and 730 days old. Large quantities of rough endoplasmic reticulum and peripheral secretory microvesicles were observed in the calcaneal tendon of 30-day-old rats. In the case of the deep digital flexor tendon, this organelle remained well-developed up to 180 days. A marked decrease in rough endoplasmic reticulum was observed in both tendons in 730-day-old rats. Proteoglycans associated with collagen fibrils were visible in the two tendons of all age groups. The reduced amount of rough endoplasmic reticulum and secretory microvesicles may be correlated with the known lower turnover of extracellular matrix components during aging.

The Martin-Gruber anastomosis in brazilians: an anatomical study

Communications between nerves are relatively common, and individual variations in their anatomical organization have been described. Knowledge of the prevalence of such variations is necessary when estabilishing the diagnosis of neuropathies and surgical landmarks. In this study, 64 anterior forearm regions of cadavers of blacks and whites of both sexes, were dissected to examine the communications between the median and ulnar nerves (Martin-Gruber anastomosis). This anastomosis was found in five cases (7,8%), one of which was bilateral. There were no significant gender or racial differences in the incidence of this connection. The anastomosis in Brazilians observed here, the impoprtance of an adequate investigation of these connections needs to be underscored. Understanding the existence of this variations, its location and its possible presentation is important for correct patient assistance.