Alena Peixoto Medrado

Influence of 670 nm low-level laser therapy on mast cells and vascular response of cutaneous injuries

Laser biomodulation has been getting considerable attention when it comes to its effects on the inflammatory process. Its action upon mast cells have been already studied, but none of the previous papers related the resulting effect to the inflammatory and vascular status of the wounds. Therefore, the acute inflammatory process as well as the mast cells behavior and the vascular response were analyzed under the influence of laser treatment on cutaneous wounds. Surgical procedures were performed on 60 rats divided into sham and laser groups. Low-level laser therapy was performed following surgical procedures (670 nm, 9 mW, 4 J/cm(2), 124 s). Histological specimens were analyzed for cell morphology and immunohistochemistry using anti-von Willebrand Factor and anti-Vascular Endothelial Growth Factor antibody. Laser treatment resulted in an increased acute inflammatory response in irradiated tissues; surgical wounds treated with laser therapy had increased polymorphonuclear cells, mast cells and vasodilation and lower numbers of vessels than those in control rats. Laser treatment resulted in higher expression of VEGF in irradiated tissues 6-24h post-treatment (p=0.002). It is possible to observe an amplification of acute inflammatory process during the first hours after surgical procedure in rats submitted to laser therapy.

Influence of the HPA axis on the inflammatory response in cutaneous wounds with the use of 670-nm laser photobiomodulation.

This study evaluated the influence of hypothalamic-pituitary-adrenal (HPA) axis in cutaneous wounds subjected to laser biomodulation. A total of 48 rats were divided into two groups: Group I (GI) with 24 adrenalectomized animals and Group II (GII) with 24 non-adrenalectomized animals. Each group was divided into two subgroups: the irradiated subgroup which laser was applied to four points at the edges of the wound (670 nm laser, 9 mW) and control subgroup. Rats in each subgroup were sacrificed at 24 or 72 h. Adrenal glands were only removed from GI rats. Three days after adrenalectomy, a cutaneous wound was made. An immunohistochemical analysis was performed using anti-CD45 and anti-CD8 antibodies. Flow cytometry was used to count T lymphocytes and their subpopulations in blood. Decreases in the number of CD45-positive inflammatory cells and in the total numbers of CD8- and CD45-positive cells were observed in histological sections of adrenalectomized animals subjected to laser biomodulation at 24h. Similar results were observed for distribution of total lymphocytes in blood (p<0.05). The action of 670 nm laser does not depend exclusively on HPA axis. It is believed that corticosteroid-promoting enzymes liberated in non-adrenal tissues may influence immune response under the influence of this type of phototherapy.

Calcified fibrous nodules in masseter muscle - A case report and possible etiologies

Fibro-calcified nodules represent a rare group of lesions that are composed of fibrous connective tissue with calcified areas. The etiology of fibro-calcified nodules may be related to secondary changes that are caused by trauma, infectious and autoimmune diseases, or calcified thrombi. The purpose of this paper is to report the presence of a lesion of a fibro-calcified nature in the masseter muscle and its possible etiologies. The patient, a 35-year-old melanoderm female, presented with a nodule in the left masseter region with 12 months of progression. Considering the accessibility of the lesion, an excisional biopsy was performed. A histopathological examination revealed residual fibro-calcified nodules with central foci of coagulation necrosis surrounded by fatty tissue and striated skeletal muscle fibers. The test for acid-alcohol-resistant bacillus (BAAR) was negative. Two years after the surgical procedure, there were no signs of lesion recurrence. Thus, the results of histochemical staining ratified the fibro-calcified aspect of the lesion, which suggested dystrophic calcification.

PARTICIPAÇÃO DOS MASTÓCITOS NO REPARO TECIDUAL E EM LESÕES INFLAMATÓRIAS BUCAIS – UMA REVISÃO DE LITERATURA

Os mastocitos sao celulas moveis que contem grânulos, derivados da medula ossea e estao amplamente distribuidos nos tecidos conjuntivos participando ativamente das respostas imunologicas. O envolvimento destas celulas tem sido demonstrado nos processos de inflamacao, angiogenese e fibrose, nos quais atuam por meio de seus produtos de secrecao. O objetivo dessa revisao de literatura e abordar o envolvimento dos mastocitos nos fenomenos biologicos que integram o contexto do reparo tecidual, a exemplo da vasodilatacao, angiogenese e fibrose, com enfase na caracterizacao do perfil destas celulas em lesoes inflamatorias bucais. Apesar de poucos estudos contemplarem a participacao dos mastocitos em lesoes orais, alguns trabalhos tem demonstrado que tais celulas estao envolvidas na patogenese de lesoes periapicais, ulceracoes aftosas recorrentes, cistos odontogenicos, entre outros. O avanco do conhecimento acerca do mecanismo de acao dessas celulas tem estimulado o desenvolvimento de terapias cujo alvo principal e a regulacao dos mediadores quimicos liberados pelos mastocitos. Logo, espera-se que atraves de novas investigacoes, as desordens inflamatorias da cavidade oral e outras patologias que exibam mastocitos em seu intersticio, possam ser melhor compreendidas, em especial no que diz respeito ao papel biologico que estas celulas poderiam exercer nestas lesoes.