Nicotine-induced damage affects gingival fibroblasts in the gingival tissue of rats

Background: Very limited information is available from in vivo studies about whether smoking and/or nicotine affect gingival tissues in the absence of plaque. The purpose of this study is to evaluate the effect of the systemic administration of nicotine in the proliferation and counting of fibroblast‐like cells in the gingival tissue of rats. Methods: Thirty adult male Wistar rats were randomly assigned into two groups to receive subcutaneous injections of a saline solution (control group = group C) or nicotine solution (group N; 3 mg/kg) twice a day. The animals were euthanized 37, 44, or 51 days after the first subcutaneous injection. Specimens were routinely processed for serial histologic sections. Five fields of view in the connective tissue adjacent to the gingival epithelium and above the alveolar bone crest of the maxillary first molar were selected for the counting of fibroblast‐like cells. Data were statistically analyzed (P <0.05). Results: The intergroup analysis detected a lower number of fibroblast‐like cells in group N compared to group C on days 37 (2.65 ± 1.41 and 6.67 ± 3.25, respectively), 44 (2.70 ± 1.84 and 8.57 ± 2.37, respectively), and 51 (2.09 ± 1.41 and 7.49 ± 2.60, respectively) (P <0.05). The quantification of fibroblast‐like cells showed no significant difference (P >0.05) in the intragroup analysis of control and nicotine throughout experimental periods. In the intergroup analysis, group N had reduced proliferating cell nuclear antigen–positive fibroblasts compared to group C in all periods (P <0.05). Conclusion: The daily systemic administration of nicotine negatively affected, in vivo, the number and proliferation of fibroblast‐like cells in the gingival tissue of rats.     

The effect of different implant macrogeometries and surface treatment in early biomechanical fixation: an experimental study in dogs

Implant surface characterization and biomechanical testing were made to evaluate the effect of different surface treatments along with different implant bulk configurations expressed as biomechanical fixation at early implantation times. Three implant surfaces, namely bioactive ceramic electrodeposition (ED), alumina-blasted/acid etched (AB/AE), and resorbable blasting media (RBM) were fabricated in three implant macrogeometries (cylindrical, small chamber, and large chamber). All combinations between surface and bulk configurations were placed in the radii of beagle dogs (n=18), which were euthanized 14 and 40 days after surgery (n=9 animals per time in vivo). The implants were subjected to torque to interface fracture. Effects of time, surface, and macrogeometry on torque to interface fracture were evaluated by a GLM at 95% level of significance. The results showed a significant increase in torque as time elapsed in vivo (p<0.001), and that the ED surface presented significantly higher values compared to AB/AE and RBM (p<0.001) at both times. The small chamber only presented a significantly higher biomechanical fixation compared to other geometries at 40 days in vivo (p=0.02). Biomechanical fixation at 14 and 40 days was affected by implant surface treatment, whereas implant design only affected results at 40 days in vivo.     

Mast cells and ethanol consumption: interactions in the prostate, epididymis and testis of UChB rats

Citation
Mendes LO, Amorim JPA, Teixeira GR, Chuffa LGA, Fioruci BA, Pimentel TA, de Mello W Jr, Padovani CR, Pereira S, Martinez M, Pinheiro PFF, Oliani SM, Martinez FE. Mast cells and ethanol consumption: interactions in the prostate, epididymis and testis of UChB rats. Am J Reprod Immunol 2011; 66: 170–178 Problem Alcoholism has reached alarming proportions while fertility rates slowing in populations. The assessment of inflammatory effects with emphasis on the variation of the mast cells comparing ethanol chronic ingestion on reproductive organs deserves attention. Method of study The mast cells were investigated with light microscopy using toluidine blue to locate and count total mast cells and immunohistochemistry to identify the connective tissue mast cells (CTMC). Results The increase in total mast cells in the prostate, total and degranulated mast cells in epididymis of UChB rats was accompanied by a greater proportion of mucosal mast cells (MMC) in these organs. In addition, a lower incidence of degranulated mast cells was observed in epididymis of control rats. Conclusions Ethanol increases the number of total and degranulated mast cells in the prostate and epididymis, as well as associated with increasing MMC, and therefore, it could be leading to inflammation in these organs.     

Influence of ovariectomy on healing of autogenous bone block grafts in the mandible: a histomorphometric study in an aged rat model

PURPOSE: The aim of this study was to evaluate quantitatively and qualitatively the influence of estrogen deficiency on autogenous bone block grafts in aged ovariectomized rats. MATERIALS AND METHODS: Fifty 12-month-old female Wistar rats were used in the study. They were divided into 2 groups, an ovariectomized group and a sham-operated group. After 30 days the animals received autogenous block bone grafts on the angle of the mandible, harvested from the calvaria. The animals were euthanized at 7, 14, or 28 days postoperatively. RESULTS: Histologic analysis showed that at 7 days postsurgery, the interface between graft and recipient site in the sham-operated group appeared filled by a granulation tissue with angiogenic activity, whereas the ovariectomized group still exhibited a blood clot and a granulation tissue in organization. On the 14th postoperative day, the interface in the sham-operated group was partially filled by newly formed bone establishing a union between the graft and the recipient site. The interface in the ovariectomized group was typically filled by granulation tissue with discrete osteogenic activity in most specimens. On the 28th postoperative day, the graft in the sham-operated group appeared histologically integrated to the mandible. However, the interface in the ovariectomized group appeared partially filled by newly formed bone, with areas of interposed connective tissue. The statistical analysis revealed that bone neoformation was significantly greater in the sham-operated group (57.41% at 14 days and 68.35 at 28 days) in comparison with the ovariectomized group (40.82% at 14 days and 53.09 at 28 days) at the 5% level. CONCLUSION: The estrogen depletion caused by the ovariectomy hindered the healing process of autogenous block bone grafts placed in the mandibles of aged rats.     

Subgingival triclosan-polydimethylsiloxane gel as an adjunct to scaling and root planing

PURPOSE: To evaluate the influence of a triclosan-polydimethylsiloxane-containing gel when used as an adjunct to scaling and root planing on the treatment of chronic periodontal disease. METHODS: A 3-month, double-blind, randomized parallel design clinical trial was performed in 20 subjects with chronic periodontitis. The subjects, presenting at least three anterior sites with probing depth (PD) +/- 5 mm and bleeding on probing (BoP), were randomly assigned to two experimental groups: Group SRP-T: scaling/root planing plus test gel application (triclosan 1% + polydimethylsiloxane 13%) or Group SRP: scaling/root planing plus control gel application (polydimethylsiloxane 13%). Immediately following mechanical therapy, each assigned gel was applied to the selected sites and once a week during the following 3 weeks. Re-examinations were carried out on days 45 and 90 after the last irrigation. RESULTS: Significant reductions in PD and clinical attachment level (CAL) were observed for both groups in both periods (P < 0.05). However, SRP-T showed lower means of PD than SRP at Day 45 (3.60 +/- 0.87 versus 4.77 +/- 1.38, respectively, P = 0.035) and CAL at both 45 days (4.63 +/- 1.17 versus 6.07 +/- 1.43, P = 0.023) and 90 days (4.45 +/- 1.19 versus 5.91 +/- 1.37, P = 0.021). No differences were found for bleeding on probing, plaque index and gingival recession (P > 0.05) between groups.     

Impact of Her-2 Overexpression on Survival of Patients with Metastatic Breast Cancer

Introduction: Breast cancer is a complex and heterogeneous disease which is increasingly important as a public health problem. In Brazil, 57,960 new cases have been estimated to be the burden in 2016 and 2017. Despite advances in early diagnosis and therapy, approximately 20-30% of patients, even with early stage lesions, will develop distant metastatic disease. Tumors with similar clinical and pathological presentations may have differing behavior, so it is important to understand specific biological characteristics. Objective: To investigate tumor markers of primary tumors featuring pleural metastasis to identify organ-specific characteristics of metastatic breast cancer. Methods: In a historical cohort study, immunohistochemistry was performed on cell blocks of neoplastic pleural effusions and results were compared with clinicopathological data. Results: The median survival time with Her-2 overexpression in malignant pleural effusions was 2.2 months, whereas cases without overexpression survived, on average, for seven months (p = 0.02). Conclusions: We emphasize that metastases may behave independently of primary tumors, but the present results indicate that therapeutic agents targeting Her-2 overexpression could increase survival in metastatic breast cancer cases.     

Effects of Subchronic Manganese Chloride Exposure on Tambaqui (Colossoma macropomum) Tissues: Oxidative Stress and Antioxidant Defenses

This study aimed to evaluate oxidative stress parameters in juvenile tambaqui (Colossoma macropomum) exposed to 3.88 mg l^?1 Mn²⁺ for 96 hours. Biomarkers of oxidative stress, such as thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and glutathione-S-transferase (GST) activities, as well as content of reduced glutathione (GSH), were analyzed in gill, liver, brain, and kidney. The presence of Mn²⁺ in the water corresponded to increased levels of Mn²⁺ accumulation according to the following sequence: gill > kidney > brain > liver. There was a significant increase in TBARS levels (40 %) and SOD activity (80 %) in addition to a significant decrease in GSH content (41 %) in gills of fish exposed to waterborne Mn²⁺. In hepatic tissue of the exposed animals, TBARS levels decreased significantly (35 %), whereas SOD (82 %) and GST activities (51 %) as well as GSH content (43 %) increased significantly. In brain of exposed juvenile fish, only significant decreases in SOD (32 %) and CAT activities (65 %) were observed. Moreover, the kidney of exposed fish showed a significant increase in TBARS levels (53 %) and a significant decrease in SOD activity (41 %) compared with the control. Thus, the changes in biomarkers of oxidative stress were different in the tissues, showing a specific toxicity of this metal to each organ.