Search

Objectives: Fluoride (F) has been widely used to control dental caries, and studies suggest beneficial effects against diabetes when a low dose of F is added to the drinking water (10 mgF/L). This study evaluated metabolic changes in pancreatic islets of NOD mice exposed to low doses of F and the main pathways altered by the treatment., Methodology: In total, 42 female NOD mice were randomly divided into two groups, considering the concentration of F administered in the drinking water for 14 weeks: 0 or 10 mgF/L. After the experimental period, the pancreas was collected for morphological and immunohistochemical analysis, and the islets for proteomic analysis., Results: In the morphological and immunohistochemical analysis, no significant differences were found in the percentage of cells labelled for insulin, glucagon, and acetylated histone H3, although the treated group had higher percentages than the control group. Moreover, no significant differences were found for the mean percentages of pancreatic areas occupied by islets and for the pancreatic inflammatory infiltrate between the control and treated groups. Proteomic analysis showed large increases in histones H3 and, to a lesser extent, in histone acetyltransferases, concomitant with a decrease in enzymes involved in the formation of acetyl-CoA, besides many changes in proteins involved in several metabolic pathways, especially energy metabolism. The conjunction analysis of these data showed an attempt by the organism to maintain protein synthesis in the islets, even with the dramatic changes in energy metabolism., Conclusion: Our data suggests epigenetic alterations in the islets of NOD mice exposed to F levels comparable to those found in public supply water consumed by humans.

Unlabelled: Although some morphological investigations on aged human sublingual glands (HSG) found eventual phenomena identified as autolysis and mucous extravasation, the exact meaning of these findings has not been elucidated., Objective: The aim of this work is to investigate whether acinar autolysis and mucous extravasation are related to the aging process in human sublingual glands. We also speculate if autolytic changes may assist forensic pathologists in determining time of death., Material and Methods: 186 cadavers' glands were allocated to age groups: I (0-30 years); II (31-60), and III (61-90). Time and mode of death were also recorded. Acinar autolysis and mucous extravasation were classified as present or absent. Ultrastructural analysis was performed using transmission electron microscopy (TEM). Data were compared using Mann-Whitney U, Spearman's correlation coefficient, Kruskal-Wallis, and Dunn tests (p<0.05)., Results: There was correlation between age and acinar autolysis (r=0.38; p=0.0001). However, there was no correlation between autolysis and time of death. No differences were observed between genders. TEM showed mucous and serous cells presenting nuclear and membrane alterations and mucous cells were more susceptible to autolysis., Conclusion: Acinar autolysis occurred in all age groups and increased with age while mucous extravasation was rarely found. Both findings are independent. Autolysis degrees in HSG could not be used to determine time of death.

Objective: This study evaluated experimentally-induced periapical bone loss sites using digital radiographic and histopathologic parameters., Material and Methods: Twenty-seven Wistar rats were submitted to coronal opening of their mandibular right first molars. They were radiographed at 2, 15 and 30 days after the operative procedure by two digital radiographic storage phosphor plates (Digora®). The images were analyzed by creating a region of interest at the periapical region of each tooth (ImageJ) and registering the corresponding pixel values. After the sacrifice, the specimens were submitted to microscopic analysis in order to confirm the pulpal and periapical status of the tooth., Results: There was significant statistically difference between the control and test sides in all the experimental periods regarding the pixel values (two-way ANOVA; p<0.05)., Conclusions: The microscopic analysis proved that a periapical disease development occurred during the experimental periods with an evolution from pulpal necrosis to periapical bone resorption.

Unlabelled: The pathogenesis of alveolitis is not well known and therefore experimental situations that mimic some features of this disease should be developed., Objective: In this study, the evolution of the experimentally induced infection in rat sockets is characterized, which leads to clinical signs of suppurative alveolitis with remarkable wound healing disturbs., Material and Methods: Non-infected (Group I) and experimentally infected sockets in Rattus novergicus (Group II) were histometrically evaluated regarding the kinetics of alveolar healing. In addition, the characterization of the present bacteria in inoculation material and the serum levels of C-reactive protein (CRP) were performed. The detected species were Capnocytophaga ochracea, Fusobacterium nucleatum ss nucleatum, Prevotella melaninogenica, Streptococcus anginosus, Treponema socranskii and Streptococcus sanguis., Results: All experimentally infected rats developed suppurative alveolitis, showing higher levels of CRP in comparison to those non-infected ones. Furthermore, infected rats presented a significant delayed wound healing as measured by the histometric analysis (higher persistent polymorphonuclear infiltrate and lower density of newly formed bone)., Conclusion: These findings indicate that rat sockets with experimentally induced infection produced higher levels of serum CRP, showing the potential of disseminated infection and a disturb in the alveolar repair process in an interesting experimental model for alveolitis studies.

Objective: To analyze and to quantify morphological acinar postmortem changes in rat sublingual glands (SLG). MATERIAL AND METHODSs: Fifty rats were divided into two groups of 25 animals each. Group I was used for morphological and morphometric evaluations and group II for the determination of gland density and processed gland volume. Acinar autolytic changes were studied at 0 (control group), 3, 6, 12 and 24 h postmortem periods. The morphometric analysis of the volume density (Vv) and total volume (Vt) of intact (ia) and autolyzed (aa) acini was performed under light microscopy using a Zeiss II integration grid with 100 symmetrically distributed points., Results: Morphologically, temporal progressive nuclear alterations and gradual loss of the structural architecture of acinar cells were found. Regarding quantitative results, both the Vvaa and the Vvia showed statistically significant differences among all postmortem periods (p<0.05). Vvaa increased from 0.42% at 0 h to 75.84% at 24 h postmortem and Vvia decreased from 71.16% to 0% over the same period. For Vtaa and Vtia, no statistically significant differences occurred between 12-24 h and 0-3 h (p>0.05), respectively. Vtaa increased from 0.18 mm³ at 0 h to 38.17 mm³ at 12 h, while Vtia showed a decrease from 33.47 mm³ to 0 mm³ between 3-24 h postmortem. Data concerning Vtaa were adjusted by two-variable linear regression, obtaining the equation: y=-3.54+3.38x (r²=0.90). The Vtaa growth rate calculated by this equation was 3.38 mm³/h between 0-12 h., Conclusion: Acinar autolysis on rat SLG demonstrated the most significant signs during the first 6 h postmortem and was widely spread through the gland at 12 h.

Given that tobacco smoking habit is a risk factor for periodontal diseases, the aim of this study was to compare clinical periodontal aspects between smokers and non-smokers. The clinical status were assessed in 55 patients, 29 smokers and 26 non-smokers, aged 30 to 50 years, with mean age of 40. The clinical parameters used were: probing depth (PD), plaque index (PI), gingival index (GI), clinical attachment level (CAL), gingival recession (GR) and gingival bleeding index (GBI) for arches (upper and lower) and teeth (anterior and posterior). Tooth loss was also evaluated in both groups. Multiple regression analysis showed: tendency of greater probing depth and clinical attachment level means for smokers; greater amount of plaque in smokers in all regions; greater gingival index means for non-smokers with clinical significance (p<0.05) in all regions. Although, without statistical significance, the analysis showed greater gingival bleeding index means almost always for non-smokers; similar gingival recession means in both groups and tendency of upper tooth loss in smokers and lower tooth loss in non-smokers. The findings of this study showed that clinical periodontal parameters may be different in smokers when compared to non-smokers and that masking of some periodontal signs can be a result of nicotine's vasoconstrictor effect.

Little information is available on the pathogenesis of fluorosis during the fetal and initial postnatal period. In the present study, female rats received 0 (control), 7 or 100 ppm of sodium fluoride in drinking water, one week before breeding and throughout gestation and nursing periods. The hemimandibles of the offspring were collected at 0, 7 and 14 days of postnatal life (n = 5) and processed for morphological analyses by light and electron microscopy, immunohistochemical analysis for amelogenin and morphometric study of enamel matrix and ameloblasts of incisors. The results showed a decrease in matrix production at the secretory phase at all study periods for the 100 ppm group. In this same group, the secretory ameloblasts showed reduction of enamel matrix secretion, disorganization of mitochondrial crests, large vacuoles at the apical portion of the cytoplasm, retention of intracisternal material and dilatation of some cisterns in the rough endoplasmic reticulum. In the groups of animals aged 7 and 14 days, analysis of variance showed significant reduction (p<0.05) in cytoplasmic volume of 23.80% and 24.75%, respectively, in relation to the control group. The smooth-ended maturation ameloblasts exhibited a large number of vacuoles with electron-dense endocytic matrix, suggesting a delay in the resorption process. Immunohistochemical analysis showed no difference in the intensity and labeling pattern of the enamel matrix in any study group. Interestingly, in offspring at the age of 14 days for the 7 ppm group, there was an increase in the matrix length at the secretory phase. Therefore, part of the excessive dose of sodium fluoride given to the mother in drinking water can reach the offspring through the placenta and mother's milk, causing morphological changes in ameloblasts and suggesting a reduction in secretion and a delay in matrix resorption.

The tissue response to porous bovine anorganic bone implanted in rat connective tissue was evaluated by subjective light microscopy analysis. Forty rats were divided into two groups: control (empty collagen capsules) and test (collagen capsule filled with 0.1g biomaterial) and killed 10, 20, 30 and 60 days after implantation. At 10 days, intense chronic inflammatory infiltrate consisting mainly of macrophages and inflammatory multinucleated giant cells (IMGC) was observed. Neutrophils, plasma cells and lymphocytes were present in discrete amounts and slowly disappeared along the repair process. Porosity of the material was filled by reaction connective tissue exhibiting IMGC. The fibrosis was more intense after 60 days and clearly higher than the control group. Thus, the material did not cause any severe adverse reactions and did not stimulate the immune system. Based on the results it could be concluded that deproteinized bovine cancelous bone was well tolerated by rat connective tissue.

The bone tissue has a great regenerative potential, with ability to completely restore its structure and original functions. In some situations, though, bone defects cannot be self-repaired, thus requiring the use of grafts for a correct treatment and good prognosis. This work aimed at microscopically analyzing the effect of the particle size of demineralized bovine cancellous bone matrix in micro and macrogranular forms on the repair of bone defects in femurs of rabbits, with blood clot used as control. At 1, 3 and 6 months after implantation of the materials, the animals were killed and the anatomic specimens were removed. A foreign body-type granulomatous reaction containing macrophages and multinucleated giant cells in contact with the implanted particles was observed. These results suggest a failure in demineralization and/or interruption of the antigenic potential during production of the biomaterial. It is concluded that the size of the particles did not influence the evolution of the repair process of bone defects, acting only as bone-filler substances, and that the material implanted should be improved by quality control during production, since it may represent a good alternative for bone graft.

Over the last few years, various bone graft materials of bovine origin to be used in oromaxillofacial surgeries have entered the market. In the present study, we determined the capacity of a block organic bone graft material (Gen-ox, Baumer SA, Brazil) prepared from bovine cancellous bone to promote the repair of critical size bone injuries in rat calvaria. A transosseous defect measuring approximately 8mm in diameter was performed with a surgical trephine in the parietal bone of 25 rats. In 15 animals, the defects were filled with a block of graft material measuring 8mm in diameter and soaked in the animal's own blood, and in the other 10 animals the defects were only filled with blood clots. The calvariae of rats receiving the material were collected 1, 3 and 6 months after surgery, and those of animals receiving the blood clots were collected immediately and 6 months after surgery. During surgery, the graft material was found to be of easy handling and to adapt perfectly to the receptor bed after soaking in blood. The results showed that, in most animals treated, the material was slowly resorbed and served as a space filling and maintenance material, favoring angiogenesis, cell migration and adhesion, and bone neoformation from the borders of the lesion. However, a foreign body-type granulomatous reaction, with the presence of numerous giant cells preventing local bone neoformation, was observed in two animals of the 1-month subgroup and in one animal of the 3-month subgroup. These cases were interpreted as resulting from the absence of demineralization and the lack of removal of potential antigen factors during production of the biomaterial. We conclude that, with improvement in the quality control of the material production, block organic bone matrix will become a good alternative for bone defect repair in the oromaxillofacial region due to its high osteoconductive capacity.

The aim of this study was to evaluate the biocompatibility of blacks of organic bovine cancellous bone graft material (Gen-OxTM, Baumer) in ectopic sites. A cylinder of black of graft material measuring 5mm in diameter and 12mm in length was implanted in abdutor muscle of 30 Wistar rats. After 3, 7, 14, 21e 28 days, (6 animals/period) were killed, radiographies were taken and the tissues and blood were collected to histological and imunoglobuline G and M profile analysis, respectively. The analysis of the sections revelead an acute inflammatory process at 3 and 7 days, characterized by the presence of neutrophils. Absorption of the implanted matrix by mononuclear cells and scarce giant cells and their replacement by fibrous connective tissue rich in vessels and cells, was suggested. At 28 days, in most cases just remnants of the implanted matrix involved by the typical connective tissue of the perimisium were found. There was no radiographic evidence of mineral content or change in the IgG and IgM profile. On the basis in results described here, it could be concluded that the material is biocompatible and absorbable but, with no signs of osteoindutive capacity was observed.

The ameloblasts both in secretion phase and in smooth-ended ameloblasts in maturation phase were studied using stereologic methods in transmission electron microscopy (TEM). From secretion to maturation phase of amelogenesis, the nucleus volume decreased 23% and cytoplasm volume did not show significant changes; the total volume and surface of the rough endoplasmic reticulum (RER) decreased 74% and 90%, respectively, and of the mitochondria increased 742% and 384%, respectively; the surface-to-volume ratio for RER and mitochondria decrease 59% and 42%, respectively; and the predominantly apical secretory granules disappeared joined at Tomes’ process and lysosomes and phagic vacuoles have appeared principly in supranuclear cytoplasm. Although significant morphologic variation occurs from the secretory to the maturation phase of the ameloblasts, their cytoplasm volume remains unaltered.