Effects of metformin on inflammation, oxidative stress, and bone loss in a rat model of periodontitis.

AimTo evaluate the effects of metformin (Met) on inflammation, oxidative stress, and bone loss in a rat model of ligature-induced periodontitis.Materials & methodsMale albino Wistar rats were divided randomly into five groups of twenty-one rats each, and given the following treatments for 10 days: (1) no ligature + water, (2) ligature + water, (3) ligature + 50 mg/kg Met, (4) ligature + 100 mg/kg Met, and (5) ligature + 200 mg/kg Met. Water or Met was administered orally. Maxillae were fixed and scanned using Micro-computed Tomography (μCT) to quantitate linear and bone volume/tissue volume (BV/TV) volumetric bone loss. Histopathological characteristics were assessed through immunohistochemical staining for MMP-9, COX-2, the RANKL/RANK/OPG pathway, SOD-1, and GPx-1. Additionally, confocal microscopy was used to analyze osteocalcin fluorescence. UV-VIS analysis was used to examine the levels of malondialdehyde, glutathione, IL-1β and TNF-α from gingival tissues. Quantitative RT-PCR reaction was used to gene expression of AMPK, NF-κB (p65), and Hmgb1 from gingival tissues. Significance among groups were analysed using a one-way ANOVA. A p-value of p<0.05 indicated a significant difference.ResultsTreatment with 50 mg/kg Met significantly reduced concentrations of malondialdehyde, IL-1β, and TNF-α (p < 0.05). Additionally, weak staining was observed for COX-2, MMP-9, RANK, RANKL, SOD-1, and GPx-1 after 50 mg/kg Met. OPG and Osteocalcin showed strong staining in the same group. Radiographically, linear measurements showed a statistically significant reduction in bone loss after 50 mg/kg Met compared to the ligature and Met 200 mg/kg groups. The same pattern was observed volumetrically in BV/TV and decreased osteoclast number (p<0.05). RT-PCR showed increased AMPK expression and decreased expression of NF-κB (p65) and HMGB1 after 50 mg/kg Met.ConclusionsMetformin, at a concentration of 50 mg/kg, decreases the inflammatory response, oxidative stress and bone loss in ligature-induced periodontitis in rats

In-office tooth bleaching with 38% hydrogen peroxide promotes moderate/severe pulp inflammation and production of ll-1β, TNF-β, GPX, FGF-2 and osteocalcin in rats

Objectives: To study the intensity of inflammatory infiltrate and production of interleukin-1β (ll-1β), tumor necrosis factor-β (TNF-β), fibroblast growth factor-2 (FGF-2), glutathione peroxidase (GPX), and osteocalcin in response to in-office tooth bleaching in rats. Material and Methods: Twenty male Wistar rats were randomized into four groups (n=5) according to the received treatment (tooth bleaching or no treatment - control) and the period of euthanasia after treatment (24 h or 10 days). We performed tooth bleaching using a 38% hydrogen peroxide gel on maxillary and mandibular incisors. After euthanasia, incisors (20 per group) were processed for histological analysis, immunohistochemistry staining of ll-1β, TNF-β, FGF-2 and GPX and osteocalcin by immunofluorescence. We analyzed data using the Mann-Whitney and Kruskal-Wallis/Dunn tests (p<0.05). Results: The bleached groups presented statistically significant differences regarding the pulp inflammation stage compared with the control groups. Bleached teeth showed moderate/severe inflammatory infiltrate and control groups presented absent inflammatory cells or a negligible number of mononuclear cells (p<0.001) at two times (24 h and 10 days). There was strong staining for ll-1β, TNF-β, and GPX in bleached groups at 24 h and strong staining for ll-1β, TNF-β, GPX and FGF-2 at 10 days. After 10 days of tooth bleaching, the bleached group showed a statistically superior amount of osteocalcin than the other groups (p<0.01). Conclusions: Tooth bleaching with 38% hydrogen peroxide causes severe pulp inflammation, but characteristics of tissue repair after 10 days

Gliclazide reduced oxidative stress, inflammation, and bone loss in an experimental periodontal disease model

Objective: The aim of this study was to evaluate the effects of gliclazide on oxidative stress, inflammation, and bone loss in an experimental periodontal disease model. Material and Methods: Male albino Wistar rats were divided into no ligature, ligature, and ligature with 1, 5, and 10 mg/kg gliclazide groups. Maxillae were fixed and scanned using micro-computed tomography to quantify linear and bone volume/tissue volume (BV/TV) and volumetric bone loss. Histopathological, immunohistochemical and immunofluorescence analyses were conducted to examine matrix metalloproteinase-2 (MMP-2), cyclooxygenase 2 (COX-2), cathepsin K, members of the receptor activator of the nuclear factor kappa-Β ligand (RANKL), receptor activator of nuclear factor kappa-Β (RANK), osteoprotegerin (OPG) pathway, macrophage migration inhibitory factor (MIF), superoxide dismutase-1 (SOD-1), glutathione peroxidase-1 (GPx-1), NFKB p 50 (Cytoplasm), NFKB p50 NLS (nuclear localization signal), PI3 kinase and AKT staining. Myeloperoxidase activity, malondialdehyde and glutathione levels, while interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) levels were evaluated by spectroscopic ultraviolet-visible analysis. A quantitative reverse transcription polymerase chain reaction was used to quantify the gene expression of the nuclear factor kappa B p50 subunit (NF-κB p50), phosphoinositide 3-kinase (PI3k), protein kinase B (AKT), and F4/80. Results: Micro-computed tomography showed that the 1 mg/kg gliclazide treatment reduced linear bone loss compared to the ligature, 5 mg/kg gliclazide, and 10 mg/kg gliclazide treatments. All concentrations of gliclazide increased bone volume/tissue volume (BV/TV) compared to the ligature group. Treatment with 1 mg/kg gliclazide reduced myeloperoxidase activity, malondialdehyde, IL-1β, and TNF-α levels (p≤0.05), and resulted in weak staining for COX-2, cathepsin k, MMP-2, RANK, RANKL, SOD-1, GPx-1,MIF and PI3k. In addition, down-regulation of NF-κB p50, PI3k, AKT, and F4/80 were observed, and OPG staining was strong after the 1 mg/ kg gliclazide treatment. Conclusions: This treatment decreased neutrophil and macrophage migration, decreased the inflammatory response, and decreased bone loss in rats with ligature-induced periodontitis

Representações sociais sobre o risco ocupacional na perspectiva do trabalhador da saúde

Objetivou-se identificar os sentidos construídos sobre risco ocupacional por trabalhadores da saúde, através da abordagem estrutural das representações sociais. Participaram 220 profissionais de saúde de um hospital público de Natal, Rio Grande do Norte. Utilizou-se a técnica de evocação livre de palavras e os dados foram tratados analisando-se de forma articulada as médias de frequência e ordem de evocação. Os resultados mostram que os sistemas centrais têm composições diferentes nos três grupos: doença e morte nos médicos, perfurocortante e perigo nos enfermeiros e contaminação, doença, infecção e perigo nos odontólogos. A complexidade dos vínculos entre trabalho e risco sugere que estratégias e alternativas de ação sejam operacionalizadas, com a integração das diferentes categorias profissionais e ramos de conhecimento em torno de um objetivo comum, a partir de um espaço interdisciplinar, ampliando o nível de conscientização desses profissionais referente às consequências de suas práticas para a saúde

Perceção docente da supervisão pedagógica

Dissertação apresentada para a obtenção do grau de Mestre em Ciências da Educação na área de Supervisão e Orientação PedagógicaNa escola de hoje, a supervisão pedagógica pode desempenhar um papel importante na construção de uma cultura de equipa docente, baseada na partilha de experiências e saberes, em que o envolvimento de cada indivíduo se torna essencial para a identidade coletiva do grupo. O presente trabalho pretendeu conhecer a perceção docente da supervisão pedagógica através de um estudo de caso numa escola onde a investigadora exerceu a profissão docente durante vários anos. A finalidade do mesmo consistiu em perceber a existência ou não de relação entre a realidade supervisiva atual e a que se pretenderia que existisse por parte dos docentes. Os dados foram recolhidos primeiramente através de entrevistas semiestruturadas e, posteriormente, por questionários elaborados com base naquelas. Para além da análise de conteúdo, procedeu-se também à análise documental baseada em autores reconhecidos da vasta bibliografia relativa ao tema em estudo. Os resultados obtidos permitiram-nos concluir que, efetivamente, existe um desfasamento entre perceções da realidade supervisiva e perceções do que seria desejável no desempenho dessa mesma função. Com base no presente estudo empírico, pudemos apurar que a supervisão pedagógica deve sofrer alterações na sua génese. Essas alterações deverão visar um trabalho de equipa não hierarquizado, em que são fundamentais os comportamentos colaborativos numa perspetiva dialógica de trabalho. O supervisor deverá ser alguém dotado de competências sociais e cognitivas que lhe permitam fomentar a cooperação, revelando um espírito de liderança e promovendo a consecução de objetivos comuns, o que permitirá o desenvolvimento da identidade profissional docente baseada num espírito que se deseja de equipa.In nowadays school, pedagogical supervision can play an important role in the construction of teachers’ team culture based on sharing out experience and knowledge in which the involvement of each individual becomes essential for the collective group identity. The present work intended to realize the teachers’ perception concerning the pedagogical supervision troughout a case study research performed at a school where the researcher taught for several years. Its goal consisted in being aware if there was a relation between nowadays pedagogical supervising reality and the one that teachers would like to see accomplished. Data were collected, first by semi-structural interviews and then, through questionnaires which were built based on the interviews. Beyond a data content analysis, a documental analysis based on recognized authors on these matters was accomplished. The achieved results allowed us to conclude that there is a really imbalance between the perceptions of the supervising reality and the perceptions of what it would be desirable in the supervising fulfilment. According to this empirical study, we could establish that pedagogical supervision must be changed on its basis. Those changes shall aim at a non-hierarchical team work, in which collaborative behaviours are essential in a working dialogical perspective. The supervisor shall be endowed with social and cognitive competences that will allow him/her to promote cooperation, revealing leadership and promoting the achievement of common goals that will permit the development of the teaching professional identity, based on a desired team spirit. Perceção docente da Supervisão Pedagógicainfo:eu-repo/semantics/publishedVersio

Chitosan Membrane Modified With a New Zinc(II)-Vanillin Complex Improves Skin Wound Healing in Diabetic Rats

The treatment of chronic wounds is considered a public health problem. When the condition affects at-risk groups such as those with diabetics, it becomes a great clinical challenge. In this work, we evaluated the healing effects of a new zinc complex, [Zn(phen)(van)2], identified as ZPV, which was synthesized, characterized and associated with chitosan (CS) membranes and tested on cutaneous wounds of diabetic rats. Chitosan membranes were modified by Schiff base reaction with the complex under two experimental conditions (14 and 21 days), resulting in membranes with concentrations of complex equal to 0.736 μmol cm-2 (CS-ZPV1) and 1.22 μmol cm-2 (CS-ZPV2). Release assays in aqueous medium indicated that the membranes release the complex gradually when exposed to an aqueous medium. Diabetes was inducted in Wistar rats using 40 mg/kg (i.v.) streptozotocin. On the 7th day after diabetic induction, a circular excision on the skin (1.0 cm) was performed with a punch. The lesions were treated with the pure chitosan membrane and the membrane associated with the zinc-vanillin complex in two different doses. Skin samples were subjected to macroscopic and histopathological analyses, cytokine (TNF-α, IL-1β, and IL-10) quantification and reverse transcriptase polymerase chain reaction (TGF-β and VEGF) assays. The analyses showed a decrease in wound size, reepithelialization, angiogenic stimulus, collagen deposition, and reduced levels of TNF-α and IL-1β as well as increased IL-10 and gene expression of TGF-β and VEGF. The evaluated parameters suggest that CS-ZPV in the two concentrations tested may be effective in the treatment of chronic wounds