RESUMO
Extracellular DNA (eDNA) is a major component of bacterial biofilms. In this study, we performed a three-dimensional analysis of Leptospira biofilm using advanced imaging by confocal laser scanning microscopy (CLSM) and multi-parameter analysis by COMSTAT 2 software, with quantification of Leptospira and eDNA fluorescence. To investigate the role of eDNA in Leptospira biofilm, we treated Leptospira biflexa biofilms with DNase I enzyme (DNase), which digested eDNA, and compared DNase treated biofilms and controls. There was a significant reduction of the biomass of biofilms treated with DNase, by spectrophotometry and COMSTAT analysis. The multiparameter analysis evidenced for DNase-treated biofilms a significant decrease in the surface area and the average thickness; opposing to a significant augmentation of the surface/biovolume ratio and the roughness coefficient (Ra*), when compared to controls. We analyzed the parameters of DNase-treated biofilms by Pearson's correlation coefficient and found significant positive correlations between biomass and average thickness; biomass and surface area; surface area and average thickness. On the other hand, there were significant negative correlations between Ra* and biomass; Ra* and average thickness; Ra* and surface area. These findings suggest that eDNA digestion results in biofilm instability and alteration of the three-dimensional architecture, justifying the negative correlation between Ra* and the above-mentioned parameters. In conclusion, our study showed that eDNA digestion produced a massive structural loss, instability, and dramatic changes in the three-dimensional architecture of Leptospira biflexa biofilm. These findings contribute to a better understanding of the role of eDNA and highlight the importance of eDNA as a key component in Leptospira biofilms.
RESUMO
OBJECTIVES: Congenital adrenal hyperplasia (CAH) is a disease that occurs during fetal development and can lead to virilization in females or death in newborn males if not discovered early in life. Because of this there is a need to seek morphological markers in order to help diagnose the disease. In order to test the hypothesis that prenatal hormones can affect the sexual dimorphic pattern 2D:4D digit ratio in individual with CAH, the aim of this study was to compare the digit ratio in female and male patients with CAH and control subjects. METHODS: The 2D:4D ratios in both hands of 40 patients (31 females-46, XX, and 9 males-46, XY) were compared with the measures of control individuals without CAH (100 males and 100 females). RESULTS: Females with CAH showed 2D:4D ratios typical of male controls (0.950 and 0.947) in both hands (P < 0.001). In CAH males the left hand 2D:4D ratio (0.983) was statistically different from that of male controls (P < 0.05). CONCLUSIONS: These finding support the idea that sexual dimorphism in skeletal development in early fetal life is associated with differences between the exposure to androgens in males and females, and significant differences associated with adrenal hyperplasia. Although the effects of prenatal androgens on skeletal developmental are supported by numerous studies, further investigation is yet required to clarify the disease and establish the digit ratio as a biomarker for CAH.