32 research outputs found

    Avaliação histométrica da ação local da calcitonina de salmão no processo de reparo ósseo: estudo em ratos

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    Neste estudo avaliou-se histometricamente a ação local da calcitonina de salmão em defeitos ósseos provocados cirurgicamente em fêmur de ratos. As avaliações foram feitas aos 7, 14 e 21 dias após o ato cirúrgico. Não se observou diferenças estatísticas aos 7 dias, entretanto no período de 14 dias houve diferenças com maior formação óssea no grupo tratado. No período de 21 dias, em ambos os grupos, não foi possível diferenciar o tecido ósseo neoformado e o adjacente. Os resultados demonstraram, que o efeito da calcitonina foi observado somente no início do processo de reparo dos defeitos ósseos criados cirurgicamente.The purpose of the present study was to histometrically evaluate the effects of salmon calcitonin on the bone healing of surgically created bone defects in rats. The animals were sacrificed 7, 14 and 21 days after the surgical procedure. After the 7- and 21-day periods, differences between the experimental and control groups were not observed (P >; 0.01). After the 14-day period, a larger amount of new bone was observed in the experimental group (P < 0.01). Thus, within the limits of the present study, it can be concluded that although salmon calcitonin positively participated in the initial phase of bone healing, it did not result in a larger amount of new bone at the end of the experimental period

    Exposure of periodontal ligament progenitor cells to lipopolysaccharide from Escherichia coli changes osteoblast differentiation pattern

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    Periodontal ligament mesenchymal stem cells (PDLMSCs) are an important alternative source of adult stem cells and may be applied for periodontal tissue regeneration, neuroregenerative medicine, and heart valve tissue engineering. However, little is known about the impact of bacterial toxins on the biological properties of PDLSMSCs, including self-renewal, differentiation, and synthesis of extracellular matrix. Objective : This study investigated whether proliferation, expression of pro-inflammatory cytokines, and osteogenic differentiation of CD105-enriched PDL progenitor cell populations (PDL-CD105+ cells) would be affected by exposure to bacterial lipopolysaccharide from Escherichia coli (EcLPS). Material and Methods : Toll-like receptor 4 (TLR4) expression was assessed in PDL-CD105+ cells by the immunostaining technique and confirmed using Western blotting assay. Afterwards, these cells were exposed to EcLPS, and the following assays were carried out: (i) cell viability using MTS; (ii) expression of the interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNF-α) genes; (iii) osteoblast differentiation assessed by mineralization in vitro, and by mRNA levels of run-related transcription factor-2 (RUNX2), alkaline phosphatase (ALP) and osteocalcin (OCN) determined by quantitative PCR. Results : PDL-CD105+ cells were identified as positive for TLR4. EcLPS did not affect cell viability, but induced a significant increase of transcripts for IL-6 and IL-8. Under osteogenic condition, PDL-CD105+ cells exposed to EcLPS presented an increase of mineralized matrix deposition and higher RUNX2 and ALP mRNA levels when compared to the control group. Conclusions : These results provide evidence that CD105-enriched PDL progenitor cells are able to adapt to continuous Escherichia coli endotoxin challenge, leading to an upregulation of osteogenic activities

    Exposure of periodontal ligament progenitor cells to lipopolysaccharide from Escherichia coli changes osteoblast differentiation pattern

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    Periodontal ligament mesenchymal stem cells (PDLMSCs) are an important alternative source of adult stem cells and may be applied for periodontal tissue regeneration, neuroregenerative medicine, and heart valve tissue engineering. However, little is known about the impact of bacterial toxins on the biological properties of PDLSMSCs, including self-renewal, differentiation, and synthesis of extracellular matrix. This study investigated whether proliferation, expression of pro-inflammatory cytokines, and osteogenic differentiation of CD105-enriched PDL progenitor cell populations (PDL-CD105+ cells) would be affected by exposure to bacterial lipopolysaccharide fromEscherichia coli (EcLPS). Toll-like receptor 4 (TLR4) expression was assessed in PDL-CD105+ cells by the immunostaining technique and confirmed using Western blotting assay. Afterwards, these cells were exposed to EcLPS, and the following assays were carried out: (i) cell viability using MTS; (ii) expression of the interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNF-α) genes; (iii) osteoblast differentiation assessed by mineralization in vitro, and by mRNA levels of run-related transcription factor-2 (RUNX2), alkaline phosphatase (ALP) and osteocalcin (OCN) determined by quantitative PCR.PDL-CD105+ cells were identified as positive for TLR4. EcLPS did not affect cell viability, but induced a significant increase of transcripts for IL-6 and IL-8. Under osteogenic condition, PDL-CD105+ cells exposed to EcLPS presented an increase of mineralized matrix deposition and higher RUNX2 and ALP mRNA levels when compared to the control group. These results provide evidence that CD105-enriched PDL progenitor cells are able to adapt to continuous Escherichia coli endotoxin challenge, leading to an upregulation of osteogenic activities232FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNão te

    Synthesis of multifunctional chlorhexidine-doped thin films for titanium-based implant materials

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    Our goal was to create bio-functional chlorhexidine (CHX)-doped thin films on commercially pure titanium (cpTi) discs using the glow discharge plasma approach. Different plasma deposition times (50, 35 and 20 min) were used to create bio-functional surfaces based on silicon films with CHX that were compared to the control groups [no CHX and bulk cpTi surface (machined)]. Physico-chemical and biological characterizations included: 1. Morphology, roughness, elemental chemical composition, film thickness, contact angle and surface free energy; 2. CHX-release rate; 3. Antibacterial effect on Streptococcus sanguinis biofilms at 24, 48 and 72 h; 4. Cytotoxicity and metabolic activity using fibroblasts cell culture (NIH-F3T3 cells) at 1, 2, 3 and 4 days; 5. Protein expression by NIH-F3T3 cells at 1, 2, 3 and 4 days; and 6. Co-culture assay of fibroblasts cells and S. sanguinis to assess live and dead cells on the confocal laser scanning microscopy, mitochondrial activity (XTT), membrane leakage (LDH release), and metabolic activity (WST-1 assay) at 1, 2 and 3 days of co-incubation. Data analysis showed that silicon films, with or without CHX coated cpTi discs, increased surface wettability and free energy (p 0.05), whereas cell metabolism (MTT assay) was affected by CHX, with the 35 min of plasma deposition time group displaying the lowest values as compared to bulk cpTi (p 0.05). Altogether, the findings of the current study support the conclusion that silicon films added with CHX can be successfully created on titanium discs and have the potential to affect bacterial growth and inflammatory markers without affecting cell viability/proliferation rates

    Novel LRAP‐binding partner revealing the plasminogen activation system as a regulator of cementoblast differentiation and mineral nodule formation in vitro

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    Amelogenin isoforms, including full‐length amelogenin (AMEL) and leucine‐rich amelogenin peptide (LRAP), are major components of the enamel matrix, and are considered as signaling molecules in epithelial–mesenchymal interactions regulating tooth development and periodontal regeneration. Nevertheless, the molecular mechanisms involved are still poorly understood. The aim of the present study was to identify novel binding partners for amelogenin isoforms in the cementoblast (OCCM‐30), using an affinity purification assay (GST pull‐down) followed by mass spectrometry and immunoblotting. Protein‐protein interaction analysis for AMEL and LRAP evidenced the plasminogen activation system (PAS) as a potential player regulating OCCM‐30 response to amelogenin isoforms. For functional assays, PAS was either activated (plasmin) or inhibited (ε‐aminocaproic acid [aminocaproic]) in OCCM‐30 cells and the cell morphology, mineral nodule formation, and gene expression were assessed. PAS inhibition (EACA 100 mM) dramatically decreased mineral nodule formation and expression of OCCM‐30 differentiation markers, including osteocalcin (Bglap), bone sialoprotein (Ibsp), osteopontin (Spp1), tissue‐nonspecific alkaline phosphatase (Alpl) and collagen type I (Col1a1), and had no effect on runt‐related transcription factor 2 (Runx2) and Osterix (Osx) mRNA levels. PAS activation (plasmin 5 µg/µl) significantly increased Col1a1 and decreased Bglap mRNA levels (p < .05). Together, our findings shed new light on the potential role of plasminogen signaling pathway in the control of the amelogenin isoform‐mediated response in cementoblasts and provide new insights into the development of targeted therapies235545454558CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e Tecnológico33003033008P8304680/2014-1Applications in CAR T-cell therapy : dissecting cellular composition using single cell multiomic

    Cyclosporine-a and bone density around titanium implants: A histometric study in rabbits

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    Aim: Cyclosporine A (CsA) is an immunosuppressive agent commonly used to prevent organ transplantation rejection. It has been demonstrated that CsA may negatively affect osseointegration around dental implants. Therefore, the aim of this study was to evaluate the effect of CsA administration on bone density around titanium dental implants. Materials and Methods: Fourteen New Zealand rabbits were randomly divided into 2 groups with seven animals each. The test group (CsA) received daily subcutaneous injection of CsA (10mg/kg body weight) and the control group (CTL) received saline solution by the same route of administration. Three days after the beginning of immunosuppressive therapy, one machined dental implant (7.00 mm in lenght and 3.75 mm in diameter) was inserted bilaterally at the region of the tibial methaphysis. After 4 and 8 weeks the animals were sacrificed and the histometrical procedures were performed to analyse the bone density around the first four threads of the coronal part of the implant. Results: A significant increase in the bone density was observed from the 4- to the 8 week-period in the control group (37.41% + 14.85 versus 58.23% + 16.38 - p <0.01). In contrast, bone density consistently decreased in the test group overtime (46.31% + 17.38 versus 16.28 + 5.08 - p <0.05). In the 8-week period, there was a significant difference in bone density between the control and the test groups (58.23 + 16.38 eand16.28 + 5.08 - p= 0.001). Conclusion: Within the limits of this study, long-term CsA administration may reduce bone density around titanium dental implants during the osseointegration process

    Steroidal And Non-steroidal Cyclooxygenase-2 Inhibitor Anti-inflammatory Drugs As Pre-emptive Medication In Patients Undergoing Periodontal Surgery.

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    The aim of the present study was to compare the pre-emptive use of a cyclooxygenase-2 (COX-2) inhibitor with a well established steroidal anti-inflammatory drug for pain and edema relief following periodontal surgery for crown lengthening. Thirty patients requiring periodontal surgery were randomly assigned to receive one of the following medications: selective COX-2 inhibitor or steroidal anti-inflammatory drug, 60 min before the surgical procedure. To examine patient anxiety, a Corah's dental anxiety scale was applied before surgery. Using a visual analog scale, the extent of pain/discomfort during the trans-operative period and immediately after the surgery was measured. Additionally, intensity of pain/discomfort and edema were examined 4, 8, 12 and 24 h postoperatively. With regard to anxiety, no statistical differences between the groups were observed (p>0.05). With respect to the extent of pain/discomfort during the trans-operative, immediate and late postoperative period, data demonstrated no significant differences (p>0.05) between the COX-2 inhibitor and steroidal groups. With regard to edema, intragroup analysis did not reveal any statistically significant difference (p>0.05) during the 24 h following surgery in either group. In conclusion, both anti-inflammatory drugs presented a similar potential for pain and edema relief following periodontal surgery.23621-

    Self-perception of generalized aggressive periodontitis symptoms and its influence on the compliance with the oral hygiene instructions - a pilot study

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    Aim: Patient&apos;s adherence to the periodontal treatment is fundamental to the success of the therapy. Lack of response to the clinician&apos;s instructions is influenced by various factors, including gender, age and psychosocial profile. The aim of the present study was to evaluate the relationship between self-perceived symptoms of generalized aggressive periodontitis and compliance with the oral hygiene instructions. Methods: Twenty-six subjects presenting a generalized aggressive form of periodontal disease were selected. The subjects answered a questionnaire to rate the perceived symptoms of periodontal disease with a sensitivity scale, in which a numeric score is attributed to each mentioned symptom. The percentage of sites with pocket probing depth (PPD) e" 5mm as well as the plaque index (PI) and gingival index (GI) were evaluated and the patients received a full mouth prophylaxis. One month later, the patients were re-evaluated for PI, GI, and PPD, and their percent reductions were correlated with the numeric score attributed to the aggressive periodontitis symptoms. Spearman&apos;s correlation and Wilcoxon&apos;s test were used with a significance level of 5%. Results: The greater the self-perception of some of the symptoms, the greater the adherence to the oral hygiene instructions. A positive correlation was observed between the reduction of GI and self perception of bleeding on tooth brushing (p=0.04, r=0.27) and redness and swelling of gums (p=0.04, r=0.26). Conclusions: The self-perception of symptoms of generalized aggressive periodontitis could have an influence on the patient&apos;s response to the oral hygiene instructions
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