Low-level laser therapy enhances the number of osteocytes in calvaria bone defects of ovariectomized rats

Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone defects of ovariectomized rats using stereology. Methods : Fifty-four Wistar rats were subjected to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups(n = ?6 per group), and 24 hours after the bone defects were created they received three, six or 12 sessions of LLLT at 0, 20 or 30 J/cm 2, using a 780-nm low-intensity GaAlAs laser. One-way ANOVA followed by Tukey ' s post hoc test was used for data processing. A difference of P < 0.05 was considered statistically significant. The parameters evaluated were osteocyte density( Nv_(ost)), total osteocyte number( Nto ost), trabecular surface density( Sv_t), and trabecular surface area( Sa_t). Results : Data obtained showed that Nto ost, Sv t, and Sa t in group G2 rats were significantly different from G1(0 J/cm^2)( P < 0.05). Compared to group G4, G5 presented higher values for the parameters Sv t and Sa t, and G6 presented significantly higher values for almost all the analyzed parameters( Nv _(ost), Nto_(ost), Sv_t, and Sa t)( P < 0.05). Compared to group G7, G8 showed a higher value only for the parameter Sa t, and G9 showed significantly higher values for parameters Nv ost, Nto ost, Sv_t, and Sa_t. Conclusion : We conclude that LLLT stimulated bone neoformation and contributed to an increase in the total number of osteocytes, especially with a laser energy density of 30 J/cm^2 given for six and 12 sessions.

Effects of Biodegradable Detergents in Morphological Parameters of Liver in Two Neotropical Fish Species(Prochilodus lineatus and Astyanax altiparanae)

Indiscriminate disposal of residues of domestic and/or industrial origin in aquatic ecosystems resulting from urban activities causes concern about their effects on the fauna. Substances absorbed by animals, such as those cited above, are metabolized by the liver, as it is the main target organ of several pollutants and also exercises basic vital functions in the organism. For this reason the liver is used as the main and most reliable biomarker in environmental studies. Thus the objective of the present study was to identify hepatic alterations resulting from exposure to water contaminated by a few commercial brands of biodegradable detergents and their effects when present together with several other contaminants found in nature. For such, a solution of 1 ppm of biodegradable detergents and water from an urban lake were tested on two widely distributed native Brazilian fish (Astyanax altiparanae and Prochilodus lineatus). Several alterations were found on the liver, including cytoplasm vacuolization, nuclear displacement, macrophage recruitment and reduced liver glycogen, showing a degenerative process in the liver of the fish, due to the action of contaminants.