1 M cacodylate buffer (pH 7.2) for 1 h at room temperature. After this, the samples were dehydrated in increasing concentrations of acetone (50%, 70%, 80% and 90%) and three immersions in pure acetone (5 min each). Next, Dr. Spurr resin was allowed to infiltrate into the pellet. For this, three different ratios of acetone/resin and times of incubation at room temperature were used: 3:1 (4 h), 1:1 (overnight) and 1:2 (8 h). Then, pure resin was added to the pellet for a further 24 h followed by one more addition of resin to the pellet. This set was placed in an oven for 48 h at 60 °C. After http://www.selleckchem.com/products/abt-199.html this period,
the material was cut using an ultramicrotome MT2B (RMC, Tucson, AZ, USA) with glass blades to obtain semi-fine cuts 1 μm thick. Dabrafenib ic50 These cuts were stained with 1%
toluidine blue in sodium borate. Next, the samples were trimmed and 70–90 nm thick cuts were obtained using an ultramicrotome MT2C (Sorvall Porter Blum, Newtown, CT, USA), equipped with a diamond blade. The cuts were collected on copper grids and contrasted with uranyl acetate and lead citrate. The grids containing the cuts were analysed by an EM-900 transmission electron microscope (Carl Zeiss, Oberkochen, Germany), operating at an acceleration voltage of 50 kV. The variables used for statistical analysis were bioactivity and structure (cell bio-volume, thickness and black spaces). The normality of errors distribution and the degree of non-constant variance were checked for each response variable using the SAS/LAB package (SAS Software, version 9.0, SAS Institute Inc., Cary, NC, USA) and data were transformed as suggested by the software, many according to Box et al.25 As the mean values of bioactivity were not normally distributed, these data were transformed by exponentiation (y2.3). The comparison between control and experimental group, for each strain, was performed using the independent sample Student’s t-test. The significant limit was set at 5%. The bioactivity and structure of C. glabrata biofilms were not altered by the presence of FLZ (p > 0.05) ( Table 1 and Table 2, Fig. 3). In contrast, a significant reduction in biofilm
bioactivity was found for C. albicans biofilms (p < 0.001) developed in the presence of FLZ. The bioactivity decreased 75% for ATCC 90028 and P01, and 60% for P34 ( Table 1). The structure of C. albicans ATCC 90028 (p < 0.001) and P01 biofilms (p < 0.05) was affected by FLZ, as shown by the increase in their thickness, cell bio-volume and black spaces ( Table 2, Fig. 1). C. albicans P34 strains showed no alteration in the structure of the biofilms developed in the presence of FLZ ( Table 2). In the z-slices of C. albicans biofilms, increases in the cell volume and the amount of black space between cells of C. albicans ATCC 90028 and P01, were observed in the presence of FLZ ( Fig. 2). However, these findings were not seen in the C. albicans P34 experimental group ( Fig. 2). FLZ caused alterations in the structure of some cells of C.