Experimental Acute Sepsis Reduced Number of Osteocalcin Immunolabeled Cells in Periodontal Ligament.

The aim of this study was to evaluate the effect of acute sepsis in the periodontal ligament, alveolar and furcation bone in absence of periodontitis induction through histological and immunohistochemical analyses. A septic rat model was established by cecal ligation and puncture (CLP). Twelve rats were randomly divided into CLP (n=6) and Sham (n=6) groups. The animals were euthanized at 24 h and hemimandibles were submitted to histomorfometric (bone matrix, collagenous fibers, fibroblasts, osteocytes, inflammatory cells, and blood vessels) and immunohistochemical (BMP-2/4, RANKL and osteocalcin) evaluation in alveolar bone, furcation bone and periodontal ligament. Our results demonstrated that histomorphometric parameters were similar in alveolar bone, furcation bone and periodontal ligament of Sham and CLP rats. Regarding to immunohistochemical analyses, the number of BMP-2/4 and RANKL immunolabeled cells was also similar in both groups. Furthermore, it was detected a reduction in the osteocalcin immunolabeled cells in periodontal ligaments of CLP compared to Sham rats (p=0.0014). In conclusion, the acute sepsis induction resulted in reduced number of osteocalcin labelled cells in periodontal ligament region. Moreover, no significant histological differences were observed in the periodontium of rats under acute sepsis. Considering the role of osteocalcin in bone remodeling, the study contributes to revealing the importance of careful periodontal evaluation in the presence of sepsis.

Experimental acute sepsis reduced number of osteocalcin immunolabeled cells in periodontal ligament

Abstract The aim of this study was to evaluate the effect of acute sepsis in the periodontal ligament, alveolar and furcation bone in absence of periodontitis induction through histological and immunohistochemical analyses. A septic rat model was established by cecal ligation and puncture (CLP). Twelve rats were randomly divided into CLP (n=6) and Sham (n=6) groups. The animals were euthanized at 24 h and hemimandibles were submitted to histomorfometric (bone matrix, collagenous fibers, fibroblasts, osteocytes, inflammatory cells, and blood vessels) and immunohistochemical (BMP-2/4, RANKL and osteocalcin) evaluation in alveolar bone, furcation bone and periodontal ligament. Our results demonstrated that histomorphometric parameters were similar in alveolar bone, furcation bone and periodontal ligament of Sham and CLP rats. Regarding to immunohistochemical analyses, the number of BMP-2/4 and RANKL immunolabeled cells was also similar in both groups. Furthermore, it was detected a reduction in the osteocalcin immunolabeled cells in periodontal ligaments of CLP compared to Sham rats (p=0.0014). In conclusion, the acute sepsis induction resulted in reduced number of osteocalcin labelled cells in periodontal ligament region. Moreover, no significant histological differences were observed in the periodontium of rats under acute sepsis. Considering the role of osteocalcin in bone remodeling, the study contributes to revealing the importance of careful periodontal evaluation in the presence of sepsis.

Resumo O objetivo deste estudo foi avaliar o efeito da sepse aguda no ligamento periodontal, osso alveolar e osso da furca por meio de análise histológica e imunohistoquímica. O modelo de sepse em ratos foi estabelecido pelo procedimento de ligação e perfuração do ceco (CLP). Doze ratos foram divididos de forma randomizada em ratos sépticos (n=6) e controle - grupo Sham (n=6). Os animais foram eutanasiados após 24 horas e suas hemimandíbulas foram submetidas aos procedimentos histotécnicos para análise histomorfométricos (matriz óssea, fibras colágenas, fibroblastos, osteócitos, células inflamatórias e vasos sanguíneos) e imunohistoquímicos (BMP-2/4, RANKL e osteocalcina) no osso alveolar, osso de furca e ligamento periodontal. Nossos resultados demonstraram que os parâmetros histomorfométricos foram similares no osso alveolar, osso de furca e ligamento periodontal dos animais do grupo sepse e do grupo Sham. Em relação à análise por imunohistoquímica, o número de células imunomarcadas para BMP-2/4 e RANKL também foi similar em ambos os grupos. Entretanto, houve redução (p=0.0014) no número de células imunomarcadas para osteocalcina no ligamento periodontal de ratos sépticos em relação ao grupo Sham. Como conclusão, o estabelecimento de sepse aguda resultou em um número reduzido de células imunomarcadas para osteocalcina na região do ligamento periodontal (p=0,0014). Além disso, não foram observadas diferenças histológicas significativas no periodonto de ratos na presença de sepse aguda. Considerando o papel da osteocalcina na remodelação óssea, este estudo contribui para revelar a importância da avaliação periodontal cuidadosa na presença de sepse.

Bone healing in critical-size defects treated with immediate transplant of fragmented autogenous white adipose tissue.

This study analyzed the influence of fragmented autogenous white subcutaneous adipose tissue (WSAT) on bone healing in critical-size defects created in rabbit calvaria. A 15-mm diameter defect was created in the calvaria of 42 rabbits, which were treated with 86 mm3 WSAT grafts or filled only with blood clots (control). Animals were euthanized at 7, 15, and 40 days postsurgery (n = 7), and the data were analyzed using histomorphometry and immunohistochemistry using the anti-CD34 and bone morphogenetic protein-2 (BMP2) antibodies. The calvaria treated with only blood clots demonstrated positivity to CD34 concentrated in endothelial cells, whereas the BMP2 were restricted to the borders of the defects. In contrast, the group treated with WSAT revealed fatty cells exhibiting positivity to BMP2 both in membrane and cytoplasm and intense quantities of stromal spindle cells that exhibited positivity to CD34 simultaneously to BMP2; these results together coincided with a larger bone matrix deposited in all postsurgery periods analyzed. These results revealed that the WSAT may be an alternative to craniofacial bone reconstruction because the adipose tissue exhibited prominent immunoexpression of BMP2, which was coexpressed with stromal CD34+ cells, indicating the plasticity of CD34+ stem cells into osteoblasts, and in the adipocytes, facts that suggest bone tissue development through cellular transdifferentiation from adipocytes.

Avaliação histológica da laserterapia de baixa intensidade na cicatrização de tecidos epitelial, conjuntivo e ósseo: estudo experimental em ratos / Histological evaluation of the effects of LLLT on the epithelial, connective and osseous tissue healing: experimental study in rats

A cicatrização é um processo fisiológico que ocorre diante de injúrias causadas em tecidos vivos. Muitas pesquisas estão sendo realizadas visando à estimulação do reparo tecidual. O objetivo deste artigo foi avaliar histologicamente a resposta de tecidos epitelial, conjuntivo e ósseo submetidos à laserterapia de baixa intensidade (LBI) em um modelo experimental de reprodução alveolar. Como metodologia, foram realizadas aplicações de LBI em quatro grupo de cinco ratos, nos seguintes parâmetros: 10mW potência única e 660 nm - 7,5 J/cm2; 660 nm - 15 J/cm2; 780 nm - 7,5 J/cm2; e 780 nm - 15 J/cm2. Os tempos experimentais foram 3, 7, 14, 21 e 28 dias. Como resultado, os tecidos epitelial e conjuntivo mostraram renovação celular atípica e acelerada durante o período de irradiação; o tecido ósseo teve sua neoformação acelerada, porém de igual padrão ao grupo controle. Concluiu-se que os tecidos epitelial e conjuntivo reagiram à estimulação de LBI com renovação celular constante. No tecido ósseo houve uma aceleração da neoformação e reparação óssea, dentro dos padrões de normalidade

Wound healing is a physiological process of live tissues. Researches have been made in order to improve this process and establish a fast patient rehabilitation. The aim of this study was to evaluate the histological effects of LLLT AsGaAl (λ = 660nm, 780nm; W = 10mW; , = 7,5; 15J/cm2; t = 5 min) on the epithelial, connective and bone tissue healing, on an alveolar model. Rats were submitted to the surgical creation of an alveolus between the lower incisor and the first mandibular molar, on both sides. After LLLT application, they were sacrificed on 3, 7, 14, 21, and 28 days. The results showed epithelial and connective tissues with accelerated growth during LLLT application; osseous tissue with accelerated neoformation, however following normal patterns. Thus, epithelial and connective tissues responded to LLLT by means of steady cellular renewal; osseous tissue showed accelerated healing, similar to the normal growth patterns