Beatriz Julião Vieira

Effects of low-level laser therapy on the progress of wound healing in humans: the contribution of in vitro and in vivo experimental studies

Low-level laser therapy is an important method for the treatment of healing processes, and several experimental studies have been carried out in search of a greater understanding of its therapeutic possibilities. The objective of this study was to review pathogenetic aspects of soft tissue repair to better understand skin lesion healing and the role of low-intensity laser in the progression of tissue healing. This study consists of a concise review of scientific literature data on the use of low-level laser and its influence on wound healing. Many studies have extensively covered the effects of using laser radiation in tissues, describing its beneficial aspects in tissue healing. However, many unanswered questions demand research on the mechanism of action and on parameters of low-level laser use in different stages of wound repair to clarify how this method acts at a cell level in healing processes.

Cellular profile of the peritumoral inflammatory infiltrate in squamous cells carcinoma of oral mucosa: Correlation with the expression of Ki67 and histologic grading

BackgroundSquamous cells carcinoma is the most important malignant tumor with primary site in the oral cavity and, given the great exposure of mucosa and lips to the etiologic factors of this neoplasm, its incidence is high. Investigation of the prognostic determinants is significant for the expectations of treatment proposal and cure of the patient. The local immune response represented by peritumoral inflammatory infiltrate is a possible prognostic factor.MethodsIn this study, oral mucosa samples of squamous cells carcinoma were analyzed, separated according to their histological classification as well as the phenotypical profile of the cells comprising the peritumoral inflammatory infiltrate was investigated by immunohistochemical method, in addiction, the cell proliferation index via protein Ki67 expression was determinated.ResultsThe T lymphocytes made up most of this inflammatory infiltrate, and among these cells, there was a predominance of T CD8 lymphocytes relative to the T CD4 lymphocytes. The B lymhocytes were the second most visualized leucocyte cell type followed by macrophages and neutrophils. The immunohistochemical assessment of Ki-67 positive cells revealed a greater expression of this protein in samples of undifferentiated squamous cells carcinoma.ConclusionThe results suggest that the cellular immune response is the main defense mechanism in squamous cells carcinoma of oral mucosa, expressed by the large number of T lymphocytes and macrophages, and that the greatest intensity of local response may be associated with the best prognosis.

Roxithromycin Reduces Cyclosporine-Induced Gingival Hyperplasia in Renal Transplant Patients

Gingival overgrowth (GO) is a common side effect of chronic cyclosporine use. The average prevalence of GO is about 30%, ranging from 10% to 85% in various series, due to diverse aggravating risk factors: drug interactions with calcium channel blockers, age, cyclosporine dose, bacterial plaque, and genetic predisposition. Recent studies have demonstrated elevated levels of specific cytokines particularly transforming growth factor-beta (TGF-beta) in hyperplastic gingival tissue, suggesting that this growth factor plays a role in the accumulation of the extracellular matrix. Until recently treatment for this complication was only surgical. Nowadays, several studies have been performed to evaluate the effects of antibiotic treatment on the regression of GO. In the present study, we used roxithromycin, a macrolide antibiotic that has inhibitory effect on TGF-beta production by inflammatory cells. The results suggested that roxithromycin may be an important therapeutic tool to reduce cyclosporine-induced GO.

Low-level laser therapy reduces delayed hypersensitivity reaction to ovalbumin in Balb/C mice.

The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) in an experimental model of delayed hypersensitivity reaction (DTH). LLLT has been used clinically to treat numerous diseases and has been tested in different experimental models, but some of its effects have yet to be explained. We assessed the effects of LLLT on DTH to ovalbumin (OVA), a protein that has commonly been used as an antigen to sensitize laboratory animals. This experimental model is broadly used to assess the effects of substances that can potentially modulate the immune system and inflammatory reactions. Balb/C mice were randomly divided into four groups: (I) immunized, untreated, and challenged (n = 6); (II) not immunized, untreated, and challenged (n = 6); (III) immunized, treated with azathioprine (AZA), and challenged (n = 6); and (IV) immunized, treated with LLLT, and challenged (n = 6). Forty-eight hours after the challenge, the animals were submitted to a paw edema test and euthanized for histopathology analysis of their plantar pads. The results obtained in DTH units were as follows: Group I, 19.6 ± 8.9; Group II, 5.8 ± 2.6; Group III, 5.6 ± 2.5; and Group IV, 5.2 ± 2.6. DTH was less intense for the groups treated with AZA and laser compared with Group I (p < 0.05). We observed no statistical difference between the AZA- and LLLT-treated groups. The slides obtained from the footpad specimens showed that AZA and laser acted similarly on the normal pattern of DTH triggering. Our results suggest that treatment with LLLT has an immunomodulatory effect on DTH to OVA.

Down-regulation of transforming growth factor beta-2 expression is associated with the reduction of cyclosporin induced gingival overgrowth in rats treated with roxithromycin: an experimental study.

BackgroundGingival overgrowth (GO) is a common side effect of the chronic use of cyclosporine (CsA), an immunosuppressant widely used to prevent rejection in transplant patients. Recent studies have reported elevated levels of specific cytokines in gingival overgrowth tissue, particularly TGF-beta, suggesting that this growth factor plays a role in the accumulation of extracellular matrix materials. The effectiveness of azithromycin, a macrolide antibiotic, in the regression of this undesirable side effect has also been demonstrated.MethodsIn this study, we created an experimental model for assessing the therapeutic effect of roxithromycin in GO and the expression of transforming growth factor beta (TGF-beta2) through immunohistochemistry. We used four groups of rats totaling 32 individuals. GO was induced during five weeks and drug treatment was given on the 6th week as follows: group 1 received saline; group 2 received CsA and was treated with saline on the 6th week; group 3 received CsA and, on the 6th week, ampicilin; and group 4 received CsA during 5 weeks and, on the 6th week, was treated with roxithromycin.ResultsThe results demonstrated that roxithromycin treatment was effective in reducing cyclosporine-induced GO in rats. Both epithelial and connective tissue showed a decrease in thickness and a significant reduction in TGF-beta2 expression, with a lower number of fibroblasts, reduction in fibrotic areas and decrease in inflammatory infiltrate.ConclusionThe present data suggest that the down-regulation of TGF-beta2 expression may be an important mechanism of action by which roxithromycin inhibits GO.

Efeito do extrato de Ginkgo biloba L., Ginkgoaceae, na osteoporose induzida em ratas Wistar

The objective of this study was to investigate the effect of a 20 day treatment with extract of Ginkgo biloba (EGb) in glucocorticoid-induced-osteoporosis. 36 rats were divided into six groups (n=6): control, osteoporosis, positive control, EGb1 (14 mg EGb/kg/day), EGb2 (28 mg EGb/kg/day) and EGb3 (56 mg EGb/kg/day). Treatments were conducted for twenty days, after osteoporosis was induced. Following euthanasia the femur and mandible of all animals were removed. The left mandible was radiographed to evaluate the cortical and the periodontal bone support (PBS). The histomorphometric analysis was performed on the right mandible and the right femur. The control group was compared with the osteoporosis group (Students t-test). The other groups were analyzed through ANOVA test followed by Dunnett post-hoc test. There was a significantly reduction in the mesial PBS, in the percentage of the alveolar bone (PAB) of the mandible and percentage of the trabecular bone (PTB) of the femur in the osteoporosis group. There was an increase in the mesial PBS in the positive control group, EGb2 and EGb3. The PAB of the mandible and the PTB of the femur increased in the EGb2 and EGb3 groups. The EGb in the 28 mg/kg and 56 mg/kg doses were effective to increase the mesial PBS, the PAB of the mandible and the PTB of the femur.