A Method for Rapid Demineralization of Teeth and Bones

Tooth and bone specimen require extensive demineralization for careful analysis of cell morphology, as well as gene and protein expression levels. The LacZ gene, which encodes the ß-galactosidase enzyme, is often used as a reporter gene to study gene-structure function, tissue-specific expression by a promoter, cell lineage and fate. This reporter gene is particularly useful for analyzing the spatial and temporal gene expression pattern, by expressing the LacZ gene under the control of a promoter of interest. To analyze LacZ activity, and the expression of other genes and their protein products in teeth and bones, it is necessary to carry out a complete demineralization of the specimen before cutting sections. However, strong acids, such as formic acid used for tooth demineralization, destroy the activities of enzymes including those of ß-galactosidase. Therefore, most protocols currently use mild acids such as 0.1 M ethylene diamine tetra-acetic acid (EDTA) for demineralization of tooth and bone specimen, which require a longer period of treatment for complete demineralization. A method by which hard tissue specimens such as teeth and bones can be rapidly, but gently, decalcified is necessary to save time and effort. Here, we report a suitable method for rapid demineralization of mouse teeth in 0.1M EDTA at 42˚C without any loss of ß-galactosidase activity

Scale morphology of Prochilodus lineatus with emphasis on the scale epithelium

The fish body is entirely covered by a thin, smooth and glandular epidermis, closely attached to the scales inserted on the dermis. The descriptive work on this tissue dates to twenty or thirty years ago, bears very little photographic record and does not focus on the scale epithelium, despite the fact that it is in direct contact with the environment. Thereupon, the present study characterizes the scale epithelium of Prochilodus lineatus, a robust species of fish. The observations show that the scale is completely covered by epithelium thicker on the proximal end of the scale, multilayered on the dorsal surface and undifferentiated on the ventral surface, and covered by mucous producing cells, mostly acid mucous. The scale is formed by plywood-like collagen matrix of collagen type III and supported by a network of elastic fibers on the ventral face. Differentiated cellular types are present, such as club cells, considered to be responsible for the release of alarm substances, which suggests possible use in environmental assessment as a non-invasive technique

Scale morphology of Prochilodus lineatus with emphasis on the scale epithelium

The fish body is entirely covered by a thin, smooth and glandular epidermis, closely attached to the scales inserted on the dermis. The descriptive work on this tissue dates to twenty or thirty years ago, bears very little photographic record and does not focus on the scale epithelium, despite the fact that it is in direct contact with the environment. Thereupon, the present study characterizes the scale epithelium of Prochilodus lineatus, a robust species of fish. The observations show that the scale is completely covered by epithelium thicker on the proximal end of the scale, multilayered on the dorsal surface and undifferentiated on the ventral surface, and covered by mucous producing cells, mostly acid mucous. The scale is formed by plywood-like collagen matrix of collagen type III and supported by a network of elastic fibers on the ventral face. Differentiated cellular types are present, such as club cells, considered to be responsible for the release of alarm substances, which suggests possible use in environmental assessment as a non-invasive technique

Low-level laser therapy improves bone formation: stereology findings for osteoporosis in rat model

© 2015, Springer-Verlag London.Low-level laser therapy (LLLT) benefits bone metabolism, but its use needs to be standardized. We evaluated the effects of LLLT on bone defects in calvaria of ovariectomized rats. Stereology was used to calculate tissue repair volume (Vtr), density of trabecular bone volume (Vvt), total volume of newly formed trabecular bone (Vtot), and the area occupied by collagen fibers (AC). Fifty-four Wistar rats were submitted to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups (n = 6), and 24 h after defects, the treatment started with a 780-nm low-intensity GaAlAs laser: G1, G2, and G3 received 3 sessions of 0, 20, and 30 J/cm2 respectively; G4, G5, and G6 received 6 sessions of 0, 20, and 30 J/cm2, respectively; and G7, G8, and G9 received 12 sessions of 0, 20, and 30 J/cm2, respectively. A normal distribution was found for all of the data. The test used to verify the normality was the Kolmogorov-Smirnov (KS, p > 0.05). The one-way ANOVA followed by Tukey’s post hoc test was used for data processing. A difference of p tr, Vvt, Vtot, and (AC). Results were significant for (Vvt) and (Vtot) between G3 and G1. There were no significant results between G5 and G4 as well as between G8 and G7. Groups G6 and G4 results showed statistical difference for Vtr, Vvt, Vtot, and (AC). Groups G9 and G7 showed significance for Vtr, Vvt, Vtot, and (AC). In conclusion, there was new bone formation in the groups that received 20 and 30 J/cm2 when compared to control groups, but over time, the dose of 30 J/cm2 showed better stereological parameters when compared to 20 J/cm2

Low-level laser therapy improves bone formation: stereology findings for osteoporosis in rat model

© 2015, Springer-Verlag London.Low-level laser therapy (LLLT) benefits bone metabolism, but its use needs to be standardized. We evaluated the effects of LLLT on bone defects in calvaria of ovariectomized rats. Stereology was used to calculate tissue repair volume (Vtr), density of trabecular bone volume (Vvt), total volume of newly formed trabecular bone (Vtot), and the area occupied by collagen fibers (AC). Fifty-four Wistar rats were submitted to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups (n = 6), and 24 h after defects, the treatment started with a 780-nm low-intensity GaAlAs laser: G1, G2, and G3 received 3 sessions of 0, 20, and 30 J/cm2 respectively; G4, G5, and G6 received 6 sessions of 0, 20, and 30 J/cm2, respectively; and G7, G8, and G9 received 12 sessions of 0, 20, and 30 J/cm2, respectively. A normal distribution was found for all of the data. The test used to verify the normality was the Kolmogorov-Smirnov (KS, p > 0.05). The one-way ANOVA followed by Tukey’s post hoc test was used for data processing. A difference of p tr, Vvt, Vtot, and (AC). Results were significant for (Vvt) and (Vtot) between G3 and G1. There were no significant results between G5 and G4 as well as between G8 and G7. Groups G6 and G4 results showed statistical difference for Vtr, Vvt, Vtot, and (AC). Groups G9 and G7 showed significance for Vtr, Vvt, Vtot, and (AC). In conclusion, there was new bone formation in the groups that received 20 and 30 J/cm2 when compared to control groups, but over time, the dose of 30 J/cm2 showed better stereological parameters when compared to 20 J/cm2