Chemopreventive Activity of Systemically Administered Curcumin on Oral Cancer in the 4-Nitroquinoline 1-Oxide Model

Curcumin has therapeutic potential in preventing several types of cancer, including colon, liver, prostate, and breast. The goal of this study was to evaluate the chemopreventive activity of systemically administered curcumin on oral carcinogenesis induced by 4-nitroquinolone-1-oxide (4-NQO). A total of 50 male albino rats, Rattus norvegicus, (Holtzman), were divided into five groups (n = 10 per group). Four of these groups were exposed to 50 ppm 4-NQO in their drinking water ad libitum for 8 or 12 weeks, two groups were treated with curcumin by oral gavage at 30 or 100 mg/kg per day, and one group was treated with corn oil (vehicle) only. The negative control group was euthanized at baseline. Tongues of all animals were removed after euthanasia and used in the subsequent analysis because the tongue is the primary site of carcinogenesis in this model. Descriptive histological analysis and immunohistochemistry for PCNA, Bcl-2, SOCS1 e-3, and STAT3 were performed to assess the oncogenic process. The gene expression of Vimentin, E-cadherin, N-cadherin, or TWIST1 was assessed using RT-qPCR as a representative of epithelial-mesenchymal transition (EMT) events. The administration of curcumin at 100 mg/kg during the 12 weeks markedly decreased the expression of PCNA, Bcl-2, SOCS1 e-3, and STAT3. Curcumin also minimized the cellular atypia under microscopic analysis and diminished the expression of the genes associated with EMT. These findings demonstrate that the systemic administration of curcumin has chemopreventive activity during oral carcinogenesis induced by 4-NQO. J. Cell. Biochem. 116: 787-796, 2015. (C) 2014 Wiley Periodicals, Inc.

Renal and vascular effects of Crotalus durissus cumanensis venom and its crotoxin fraction

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of crystallized biosilicate in the reconstruction of calvarial defects

The objective of this study was to assess the bone repair process of crystallized Biosilicate in surgically created defects on rats' calvaria. This biomaterial was recently developed for odontological use. We used fifteen rats (rattus norvegicus albinus, Wistar), and two 5 mm surgical defects were performed on each of them; the defects were made with trephine drill on the calvarium region prior to the biomaterial placement. Groups were divided as follows: Group 1-defect filled with clot; Group 2-defect filled with crystallized Biosilicate. After 7, 14 and 28 days the animals were killed, the parts were retrieved and slides were prepared for histological studies. Bone formation was satisfactory in all groups, with direct contact between biomaterial surface and bone and absence of infection signs. The 28 days periods showed better results, and statistically significant difference between Clot Group (90.2 %) and Biosilicate (58 %; p = 0.002) was seen, regarding presence of bone tissue on the surgical defects. Our study revealed that defects filled with clot present better results on bone formation compared to crystallized Biosilicate, which is considered a biocompatible material with favorable osteoconductive properties.

Delayed tooth replantation in rats: effect of systemic antibiotic therapy with amoxicillin and tetracycline

Systemic antibiotic therapy (SAT) has usually been recommended after tooth replantation, but its actual value has been questioned. As there are no reports in the literature about its influence on tooth replantation, the aim of this study was to evaluate the influence of systemic administration of antibiotics (amoxicillin and tetracycline) at the different phases of the repair process (7, 15, 30 days) in delayed rat tooth replantation. Ninety Wistar rats (Rattus norvegicus albinus) had their maxillary right incisors extracted and bench-dried for 60 min. The dental papilla, enamel organ, pulp tissue, and root surface-adhered periodontal ligament were removed, and the teeth were replanted. The animals received no antibiotics (n = 30) or were medicated systemically with amoxicillin (n = 30) and tetracycline (n = 30), and were euthanized after 7, 15, and 30 days. Regardless of the evaluation period, the acute inflammatory infiltrate was less intense and root resorption presented smaller extent and depth in the group treated with amoxicillin. The results suggest that SAT has a positive influence on the repair process in delayed tooth replantation and that amoxicillin is an excellent treatment option.

TNF-alpha and IL-6 immunohistochemistry in rat renal tissue experimentaly infected with Leptospira interrogans serovar Canicola

Leptospirosis is a public health problem worldwide and its etiology remains unclear. Its pathogenesis involves a complex interaction between host and infecting microorganism. The inflammatory reaction that controls the infection process also underscores many pathophysiological events occurring in leptospirosis. We investigated the presence of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in renal tissues by immunohistochemical and histopathological examination in animals experimentally inoculated with Leptospira serovar Canicola. All the tests were carried out 2, 7, 14, 21 or 28 days after inoculation. Although TNF-alpha and IL-6 had been detected in tissues throughout the observation period, these cytokines appeared more intensely during the initial phase of infection. Therefore, both TNF-alpha and IL-6 were associated with the immunopathogenesis of leptospirosis. This profile suggests a high immunocellular response throughout the early infection stages followed by subsequent humoral response.

Influência da inalação da fumaça de cigarro no reparo de enxertos ósseos autógenos onlay em ratas ovarectomizadas: estudo histomorfométrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação histológica da ação da raioterapia na região odontogênica de incisivos de ratos

Inúmeras alterações dentárias podem ocorrer em crianças submetidas ao tratamento radioterápico. O objetivo neste trabalho foi avaliar histologicamente a ação da radiação X na região odontogênica do incisivo inferior de ratos com doses de 5 e 15 Gy. Foram utilizados 30 ratos machos (Rattus norvegicus, Albinus, Wistar), os quais foram divididos em três grupos: controle; radioterapia 5 Gy (irradiados com 5 Gy); e grupo 15 Gy (irradiados com 15 Gy). As doses foram administradas na região de cabeça e pescoço, em dose única, no segundo dia do experimento. As mandíbulas foram preparadas em lâminas histológicas. Na porção inicial da região odontogênica do grupo 5 Gy, os odontoblastos apresentaram-se alterados morfologicamente e menos organizados. Já no grupo 15 Gy foram observadas irregularidades na organização dos odontoblastos e ameloblastos, além de alteração na formação da alça epitelial e hemorragia. Na porção média da região odontogênica, o grupo 5 Gy apresentou alterações na face lingual, bem como leves alterações nos odontoblastos na região distal do dente; o órgão dentário do grupo 15 Gy apresentou visível redução do tamanho, hemorragia, odontoblastos não polarizados e produção de dentina para diferentes direções; observando-se ainda na porção distal, extensa destruição com visível redução no tamanho e vasta desorganização nos odontoblastos e ameloblastos. Conclui-se que a dose de 5 Gy causou leves e pequenas alterações morfológicas, e a dose de 15 Gy provocou intensas alterações histológicas e estruturais na região odontogênica do incisivo de rato.

Avaliação da movimentação dentária induzida após trauma de subluxação: estudo experimental em ratos

Objetivo: avaliar as alterações histológicas ocorridas na área periodontal de molares de ratos submetidos à movimentação dentária induzida (MDI), logo após um trauma intencional (subluxação). Métodos: quarenta ratos Wistar machos adultos (Rattus norvegicus albinus) foram selecionados. Os animais foram divididos em oito grupos (n = 5), de acordo com a combinação das variáveis: Grupo 1 – controle (sem trauma e sem MDI); Grupo 2 – MDI; Grupos 3, 4, 5 e 6 – grupos de trauma dentoalveolar correspondendo, respectivamente, para 1, 3, 8 e 10 dias após o trauma; Grupos 7 e 8 – os molares murinos foram submetidos a um impacto de 900cN e, de um e três dias após o evento trauma, o movimento do dente foi induzido. Os primeiros molares superiores dos animais foram movidos mesialmente durante sete dias, com uma mola fechada (50cN). Após período experimental de cada grupo, os animais foram sacrificados por overdose anestésica e as maxilas direitas foram removidas e processadas para análise histológica qualitativa. Resultados: nos animais dos grupos 3, 4, 5 e 6, as alterações histológicas não foram muito significativas. Consequentemente, o efeito do movimento dentário induzido logo após um evento de subluxação (grupos 7 e 8) foi muito semelhante ao descrito para o grupo 2. Conclusão: não houve diferença na qualidade do reparo periodontal quando a MDI foi aplicada aos dentes que sofreram um trauma de subluxação.

Effect of oral infections on serum creatinine levels in diabetic rats

Aim: The aim of this study was to evaluate the relationship between pulpal and/or periodontal disease and serum creatinine levels in a rat model of diabetes mellitus. Methods: Eighty male rats (Rattus norvegicus albinus, Wistar) were divided into the following 8 groups compris-ing 10 animals each: normal (G1), with pulpal disease (G2), with periodontal disease (G3), with both pulpal and periodontal disease (G4), diabetic (G5), diabetic with pulpal disease (G6), diabetic with periodontal disease (G7), and diabetic with both pulpal and periodontal disease (G8). Diabetes was induced by injecting streptozotocin, pul-pal disease were induced by exposing pulpal tissue to the oral environment, and periodontal disease was induced by periodontal ligature. After 30 days, blood was collected by cardiac puncture and the animals were killed. The maxillae were processed for histopathology. Serum creatinine levels were measured by the enzymatic method. The total assessed values were statistically analyzed by analysis of variance and Tukey’s test (p < 0.05). Results: Serum creatinine levels were significantly higher in diabetic rats than that in all normoglycemic rats (p < 0.05). The presence of pulpal and periodontal disease increased the serum creatinine levels in normoglycemic and diabetic rats, but there was no statistical difference between the groups (p > 0.05). Conclusions: We found that the serum creatinine level was higher in diabetic rats and may be related to the pres-ence of oral infections. Clinical significance: Changes in serum creatinine level may be related to the presence of oral infections and diabetes.

Remodelação óssea com as forças contínua, contínua interrompida e intermitente: movimentação dentária induzida em ratos

Pós-graduação em Odontologia - FOA

Efeito da antibioticoterapia sistêmica com amoxicilina e tetraciclina no processo de reparo da injúria de luxação extrusiva

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da teneurina-2 (Ten-2) nos astrócitos do córtex cerebral de ratos adultos após lesão mecânica. Estudo imuno-histoquímico e de expressão gênica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da inalação da fumaça de cigarro na regeneração óssea guiada em enxertos autógenos onlay em ratas com deficiência estrogênica: estudo histomorfométrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)