Effect of Er,Cr:YSGG and Er:YAG laser irradiation on the adhesion of blood components on the root surface and on root morphology

The aim of this study was to conduct an in vitro evaluation, by scanning electron microscopy (SEM), of the adhesion of blood components on root surfaces irradiated with Er,Cr:YSGG (2.78 µm) or Er:YAG (2.94 µm) laser, and of the irradiation effects on root surface morphology. Sixty samples of human teeth were previously scaled with manual instruments and divided into three groups of 20 samples each: G1 (control group) - no treatment; G2 - Er,Cr:YSGG laser irradiation; G3 - Er:YAG laser irradiation. After performing these treatments, blood tissue was applied to 10 samples of each group, whereas 10 samples received no blood tissue application. After performing the laboratory treatments, the samples were observed under SEM, and the resulting photomicrographs were classified according to a blood component adhesion scoring system and root morphology. The results were analyzed statistically (Kruskall-Wallis and Mann Whitney tests, α= 5%). The root surfaces irradiated with Er:YAG and Er,Cr:YSGG lasers presented greater roughness than those in the control group. Regarding blood component adhesion, the results showed a lower degree of adhesion in G2 than in G1 and G3 (G1 × G2: p = 0.002; G3 × G2: p = 0.017). The Er:YAG and Er,Cr:YSGG laser treatments caused more extensive root surface changes. The Er:YAG laser treatment promoted a greater degree of blood component adhesion to root surfaces, compared to the Er,Cr:YSGG treatment.

Efectos de la luz UV sobre placas de titanio para la adhesión osteoblástica / The effects of ultraviolet irradiation of titanium plates on osteoblastic adhesion

Objetivo: investigar los efectos de la irradiación ultravioleta (UV) sobre placas de titanio (Ti) para la adhesión osteoblástica por medio de un método colorimétrico simple y reproducile para determinar la densidad celular. Materiales y métodos: dos diferentes tamaños (10x10x0.5 mm y 20x20x0.5 mm) de placas (n=10 c/gp) fueron obtenidas de una hoja de Ti puro y divididas en dos grupos (n=5/gp) para cada tamaño de placa. La superficie de las placas de Ti fue pulida, observada con microscopía electrónica de barrido (MEB) y estimada la rugosidad de la superficie pulida. Para el grupo experimental, las placas de Ti fueron irradiadas a una longitud de onda de 253.7 nm con luz UV durante 5, 20, 40, 60 minutos ó 4 y 6 horas. Células odontoblásticas de ratón MC3T3-E1 fueron cultivadas en medio alfa mínimo esencial (-MEM) e inoculadas sobre cada placa de Ti. El número de células adheridas y proliferadas fue determinado por medio del método MTT y el consumo de animoácidos. Resultados: 20 minutos de irradiación UV de las placas de Ti fueron suficientes para incrementar significativamente (p<0.05) la adhesión y proliferación celular, acompañado de un mayor consumo de aminoácidos. Conclusiones: la irradiación UV sobre placas de Ti incrementó significatiamente la adhesión celular por medio del método MTT, confirmando la potencialidad de la luz UV.

Effect of Ultraviolet Light on the Expression of Adhesion Molecules and T Lymphocyte Adhesion to Human Dermal Microvascular Endothelial Cells

In order to determine the effect of ultraviolet radiation (UVR) on the cell adhesion molecules expressed in human dermal microvascular endothelial cells (HDMEC), the cells were exposed to varying UVR doses and the cell surface was examined for expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM- 1), and E-selectin. The effect of UVB irradiation on the binding of T lymphocytes to HDMEC was also examined. UVA irradiation did not affect the surface expression of ICAM-1, VCAM-1, or E-selectin on the HDMEC. However, following UVB exposure, ELISA demonstrated a significant increase in the baseline ICAM-1 cell surface expression on the HDMEC. However, no induction of either E-selectin or VCAM-1 was noted. UVB also significantly augmented ICAM-1 induction by IL-1 alpha and TNF- alpha. VCAM-1 was induced by stimulating HDMEC with IL-1alpha following a UVB irradiation dose of 100 mJ/cm2. Flow cytometric analysis of the HDMEC stimulated with IL-1 alpha for 24h demonstrated that 12% of the cells expressed VCAM-1 but either IL-1 alpha or UVB irradiation alone failed to induce VCAM-1 expression. Enhancement of T cell-HDMEC binding by IL-1 alpha; or TNF- alpha treatment was not significantly affected after UVB irradiation. This study demonstrated that UVB irradiation can alter ICAM-1 and VCAM-1 expression on the HDMEC surface and that augmentation of ICAM-1 expression and the IL-1 alpha -dependent induction of VCAM-1 following UVB exposure might be important steps in the pathogenesis of sunburn.

Schistosoma mansoni: inflammatory foci around larvae in the peritoneal cavity of naive mice is radiosensitive

Innate attack to Schistosoma mansoni cercariae was evaluated in irradiated mice. It was observed that 70 percent of the larvae from mice sacrificed one day after whole body irradiation with 400 or 800 rads were surrounded by cluster reactivities, without difference from controls. Differences were apparent on day 5 after irradiation with sub lethal (400 rads) or lethal doses (800 rads) suggesting that innate defence to infection take at least 5 days to be affected by low dose whole-body radiation