A Model to Study Gland Regeneration/Development in Rat: The Expression of Metalloproteinase- 9 and Extracellular Matrix Proteins

A model to study gland regeneration as a similar phenomenon to gland development is proposed. This  study evaluated the expression of metalloproteinases (MMPs), laminin (LN) and type I and III collagen  in the regeneration of the rat submandibular gland (SMG). Eighteen 30-day-old Wistar male rats were  anesthetized, and the lower third of their SMG left lobe was excised. The animals were killed on the 2nd,  3rd, 7th and 15th postoperative days, and their SMG lobes were removed, fixed and processed in paraffin.  Immunohistochemistry was used to label type I and III collagen, laminin, and MMP-9. The avidin-biotin  technique was used, and the reaction was developed with diaminobenzidine. On the 2nd day, MMP9 expression  was intense in the margins of the regenerating area and inside striated duct cells in the preserved gland. On  the 3rd day, duct cytoplasm labeling persisted and was more intense than in the surrounding mesenchyme,  where labeling increased along time. Concurrently, LN labeling in the basal lamina of epithelial buds was  intense and discontinuous. Types I and III collagen were present during the whole process, which showed  their importance for the regeneration process. The behavior of extracellular macromolecules observed in  this study is similar to their behavior in gland development.

Concepción de la Mecánica Cuántica para la formación de profesores en Angola según la estructura de la correspondiente teoría física

In this article one argues the conception of the Quantum Mechanical discipline for professors of Physics in formation in Angola starting from the structure of the corresponding physical theory. The results are supplemented with the study of the learning of the students in the years lectivos 2019 and 2020 in the career of Licentiate in Education Physical Option of the Pedagogic Superior School of Bié. A mixed methodology was used in the one that you/they were considered methods and techniques so much quantitative as qualitative for the analysis and prosecution of the information. He/she was carried out a pedagogic test to evaluate the level of domain of the contents of the Quantum Mechanics in an intentional sample of 36 fourth year-old students in the course 2019 and 18 students in the 2020. The results of the learning of the students sustain the conception assumed in the investigation, when obtaining same values or superiors to the half value in a qualitative scale of three indexes.En este artículo se argumenta la concepción de la disciplina Mecánica Cuántica para profesores de Física en formación en Angola a partir de la estructura de la correspondiente teoría física. Los resultados se complementan con el estudio del aprendizaje de los estudiantes en los años lectivos 2019 y 2020 en la carrera de Licenciatura en Educación Opción Física de la Escuela Superior Pedagógica de Bié. Se utilizó una metodología mixta en la que se consideraron métodos y técnicas tanto cuantitativas como cualitativas para el análisis y procesamiento de la información. Se realizó una prueba pedagógica para evaluar el nivel de dominio de los contenidos de la Mecánica Cuántica en una muestra intencional de 36 estudiantes de cuarto año en el curso 2019 y 18 estudiantes en el 2020. Los resultados del aprendizaje de los estudiantes sustentan la concepción asumida en la investigación, al obtener valores iguales o superiores al valor medio en una escala cualitativa de tres índices

Las habilidades experimentales en la enseñanza-aprendizaje de la Física General en la formación de profesores/Experimental skills in teaching-learning of General Physics in the formation of professors

Este artículo tiene el objetivo de definir y delimitar las operaciones de las habilidades experimentales que se forman y desarrollan en los cursos de Física General y constatar su tratamiento en los currículos actuales de Física de los niveles precedentes y en la universidad. Se utilizó el método analítico-sintético, la sistematización de la teoría y de la práctica, el estudio de documentos y las técnicas experimentales para diagnosticar el desarrollo de las habilidades en los estudiantes. Se aporta el sistema de habilidades experimentales para los cursos de Física General y se fundamenta que su tratamiento en los cursos de Física que preceden al nivel universitario puede influir en el desarrollo de estas habilidades en los cursos de Física General

Efeito da obesidade e/ou periodontite induzida por ligadura na espessura da parede da aorta em ratos wistar

The purpose of this study was to evaluate aortic wall thickness after periodontal disease and/or obesity induction in a Wistar rat model. Sixty male Wistar rats were randomly divided into four groups: control (CT), periodontal disease (PD), obesity (OB), and obesity plus periodontal disease (OB+PD). Groups OB and OB+PD received cafeteria diet for 17 weeks. After they had acquired obesity (week 12), periodontal disease was induced by placing a silk ligature on the maxillary right second molar of groups PD and OB+PD. During the experimental period, body weight and Lee index were assessed. Mean alveolar bone loss (ABL) was evaluated, and aortas were prepared for histometric analysis of the aortic wall by ImageJ software. Body weight and Lee index increased in rats exposed to cafeteria diet. Mean ABL was higher in Groups PD and OB+PD than in control and OB (p<0.05). ABL was 18% higher in Group OB+PD than in Group PD, with statistically significant difference (p<0.001). Aortas were thicker in Groups OB and OB+PD than in control and PD groups, respectively (2.31mm ± 0.28 and 2.33 ± 0.29 vs. 2.18 ± 0.26 and 2.14 ± 0.27). Group OB differed significantly from the control group (p=0.036), and OB+PD and OB differed significantly from PD (p=0.004 and p= 0.001, respectively). Obesity alters aortic wall thickness in Wistar rats. However, the presence of periodontal disease did not affect the aortic wall thickness under the conditions of the present study.O objetivo deste estudo foi avaliar a espessura da parede da aorta após modelos de indução de doença periodontal e/ou obesidade em ratos Wistar. Sessenta ratos Wistar machos foram aleatoria ­ mente divididos em quatro grupos: controle (CT), doença periodontal (DP), obesidade (OB), obesidade mais doença periodontal (OB+DP). Os grupos OB e OB+DP rece beram dieta de cafeteria por 17 semanas. Após de adquirirem obesidade, (semana 12), doença periodontal foi induzido pela colocação de ligaduras de seda no segundo molar superior direito dos grupos DP e OB+DP. Durante o período experi mental, o peso corporal e índice de Lee foram obtidos. Média de perda óssea alveolar (POA) foi avaliada e as aortas preparadas para análise histométrica da parede aórtica (em mm) pelo software ImageJ. Ratos expostos a dieta de cafeteria demonstraram um aumento do peso corporal e do índice de Lee. Uma POA media maior foi observada nos grupos DP e OB+DP comparado aos grupos controle e OB (p<0.05). O grupo OB+DP, quando comparado ao grupo DP, apresentou POA 18% maior e essa diferença foi estatisticamente significativa (p<0.001). Os grupos OB e OB+DP exibiram uma espessura de aorta maior comparado aos grupos DP e controle, respectivamente (2.31 ± 0.28 e 2.33 ± 0.29 vs. 2.18 ± 0.26 e 2.14 ± 0.27). Diferenças significativas foram observadas nas comparações dos grupos OB e controle (p=0,036), e OB+DP e OB comparado ao grupo DP (p=0.004 e p= 0.001, respectivamente). A obesidade parece afetar a espessura da parede da aorta em ratos Wistar. Entretanto, a presença de doença periodontal não afetou a espessura da parede da aorta sob as condições do presente estudo

Effects of low molecular weight heparin on alveolar bone loss in wistar rats

This study aimed to assess the effects of low molecular weight heparin (LMWH) on alveolar bone loss (ABL), blood count, and counting of megakaryocytes and adipocytes in male Wistar rats. Forty male 60-day Wistar rats were randomly divided into four groups: Control (C), Periodontal Disease (PD), Heparin (Hp) and Heparin + Periodontal Disease (Hp+PD). LMWH was applied for 60 days at doses of 1 ml/kg/day. Blood samples were collected at baseline, 30 and 60. On day-49, PD and Hp+PD groups were subjected to ligature-induced periodontitis around second upper right molar. The left side was assessed as spontaneous alveolar bone loss. Mean ABL in the side with ligature showed significantly different between C (0.35±0.07 mm) and Hp+DP (0.49±0.09 mm) groups (p<0.001), between PD (0.55±0.11 mm) and Hp (0.32±0.06 mm) groups (p<0.001) and between Hp and Hp+DP groups (p<0.001). No significant differences were found among groups for ABL in the side without ligature. Animal weight, food intake, and water consumption showed no statistically significant difference among groups. Megakaryocytes and adipocytes were counted using optical microscopy and no statistically significant differences were found. Within-groups, there were an increase and a decrease, respectively, in the counting of lymphocytes (p=0.005 for C and p=0.009 for Hp+PD groups only) and leukocytes (p=0.003 for C, p=0.001 for PD, p=0.002 for Hp, and p<0.001 for Hp+PD groups). There was no decrease in the number of platelets in the three collection periods. LMWH was not able to affect ABL, but it may change the blood counting, especially increasing lymphocytes

Effect of inhaled corticosteroid on TNF-α production and alveolar bone loss in Wistar rats

AbstractObjectiveTo evaluate the effect of different concentrations of inhaled budesonide on secretion of tumoral necrosis factor-alpha (TNF-α) and on ligature-induced alveolar bone loss in Wistar rats.Materials and methodsForty-two animals were randomly divided in four groups. Control group (G1) did not receive any procedure. For the other 3 groups, alveolar bone loss was induced by placement of ligatures around the upper second molar. The contralateral molar was considered intra-group control. Group 2 (G2) was nebulized with saline solution (NaCl 0.9%). Groups 3 and 4 (G3 and G4) were nebulized with 30μg and 100μg budesonide, respectively. Administration of drugs was performed daily for 14 days. Blood samples were collected from all animals for analysis of TNF-α. The maxillae from G2, G3 and G4 were removed and defleshed with 9% sodium hypochlorite. Morphometric analysis of bone loss was performed in digital standard photographs. Statistical analysis was performed with one-way ANOVA, followed by Tukey HSD or Scheffé multiple comparison's test (significance level P≤0.05).ResultsMean alveolar bone loss values for teeth with ligature were 0.72, 0.70 and 0.77mm for Groups 2, 3 and 4, respectively. No statistically significant differences were found amongst groups with or without ligature. The production of TNF-α was 60% higher in the presence of ligature (G1 vs. G2/G3/G4). No effect was observed in TNF-α secretion after inhalation of budesonide.ConclusionInhaled budesonide in different concentrations did not alter alveolar bone loss and TNF-α secretion in male Wistar rats

Disparidades na saúde bucal de homens e mulheres da região metropolitana de Porto Alegre

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Periodontal disease affects oral cancer progression in a surrogate animal model for tobacco exposure

For decades, the link between poor oral hygiene and the increased prevalence of oral cancer has been suggested. Most recently, emerging evidence has suggested that chronic inflammatory diseases from the oral cavity (e.g., periodontal disease), to some extent, play a role in the development of oral squamous cell carcinoma (OSCC). The present study aimed to explore the direct impact of biofilm‑induced periodontitis in the carcinogenesis process using a tobacco surrogate animal model for oral cancer. A total of 42 Wistar rats were distributed into four experimental groups: Control group, periodontitis (Perio) group, 4‑nitroquinoline 1‑oxide (4‑NQO) group and 4NQO/Perio group. Periodontitis was stimulated by placing a ligature subgingivally, while oral carcinogenesis was induced by systemic administration of 4NQO in the drinking water for 20 weeks. It was observed that the Perio, 4NQO and 4NQO/Perio groups presented with significantly higher alveolar bone loss compared with that in the control group. Furthermore, all groups receiving 4NQO developed lesions on the dorsal surface of the tongue; however, the 4NQO/Perio group presented larger lesions compared with the 4NQO group. There was also a modest overall increase in the number of epithelial dysplasia and OSCC lesions in the 4NQO/Perio group. Notably, abnormal focal activation of cellular differentiation (cytokeratin 10‑positive cells) that extended near the basal cell layer of the mucosa was observed in rats receiving 4NQO alone, but was absent in rats receiving 4NQO and presenting with periodontal disease. Altogether, the presence of periodontitis combined with 4NQO administration augmented tumor size in the current rat model and tampered with the protective mechanisms of the cellular differentiation of epithelial cells

New tendencies in non-surgical periodontal therapy

The aim of this review was to update the evidence of new approaches to non-surgical therapy (NSPT) in the treatment of periodontitis. Preclinical and clinical studies addressing the benefits of adjunctive antimicrobial photodynamic therapy, probiotics, prebiotics/synbiotics, statins, pro-resolving mediators, omega-6 and -3, ozone, and epigenetic therapy were scrutinized and discussed. Currently, the outcomes of these nine new approaches, when compared with subgingival debridement alone, did not demonstrate a significant added clinical benefit. However, some of these new alternative interventions may have the potential to improve the outcomes of NSPT alone. Future evidence based on randomized controlled clinical trials would help clinicians and patients in the selection of different adjunctive therapies

Investigation of oral and general health status and IL-1β gene polymorphism as risk factors for oral mucositis in hematopoietic stem cell transplantation patients

The aim of the present study was to analyze the relationship of OM with possible risk factors such as oral health condition, immunological status and IL-1β profile in patients submitted to hematopoietic stem cell transplantation (HSCT). Fifty-four individuals submitted to HSCT were included. All patients received previous dental treatment and photobiomodulation (PBM) as the institutional OM preventive protocol. OM scores, immune status, and IL-1β levels were determined during the conditioning period and at D+3 and D+8 after HSC infusion. IL-1β gene polymorphism was also analyzed during conditioning. Possible associations of OM with risk factors were analyzed using conditional Fisher’s exact test. OM was observed in 34 patients (62.9%) classified as Grade 1 (13 patients/24.1%), Grade 2 (14 patients/25.9%), Grade 3 (3 patients/5.5%), and Grade 4 (4 patients/7.4%). Allogeneic HSCT individuals exhibited a higher OM grade than autologous subjects. Moreover, an association was observed between severe OM and severe gingivitis (p = 0.01), neutropenia (p = 0.03), and leukopenia (p = 0.04). A significant association between OM and lower IL-1β levels was detected at three time points, i.e., conditioning (p = 0.048), D+3 (p = 0.01), and D+8 (p = 0.005). The results showed that IL-1β gene polymorphism was not associated with OM. Our study provided important insights into the scope of OM risk factors in the setting of HSCT. Patients submitted to HSCT with severe gingivitis prior to chemotherapy and with severe neutropenia and leukopenia exhibited a higher OM grade. Further investigation will be necessary to better understand the exact role of IL-1β in the context of OM pathobiology and to validate cytokine analysis in larger cohorts