A stereological study of developmental changes in hepatocyte ultrastructure of zebrafish (Danio rerio)

Exploring DiPP (diisopentyl phthalate) neurotoxicity and the detoxification process in zebrafish larvae - A Silent contaminant?

Diisopentyl phthalate (DiPP) is present in many consumer goods, but can be absorbed into the human body, and can disrupt the endocrine system affecting reproductive health and fetal development. Studies revealed that biological samples of pregnant women in Brazil contained DiPP, raising even more the concerns about its usage. This study investigated how DiPP concentrations (12.5-1000 μg l-1) affect the different developmental stages (24, 48, 72, 120, and 144 hpf) of embryos and larvae of zebrafish. DiPP induced deleterious alterations in neuromuscular development and morphometry of organs, Low concentrations of DiPP decreased acetylcholinesterase and cellular energy allocation concomitantly with increased glutathione S-transferase. Zebrafish swimming period seemed to be decreased not only due to direct neurotoxicity, but also to less allocation of energy for behavioral purposes. Moreover, high concentrations of DiPP induced spinal deformities and developmental alterations specially of the eye and liver of larvae. These findings emphasize that DiPP exerts complex effects that should be considered when assessing its potential effects on health of humans and the total environment. The biomarkers and behavioral parameters showed to be good complimentary early-warning tools exhibiting a high sensitivity compared to FET.

Rabbit Endothelial Progenitor Cells Derived From Peripheral Blood and Bone Marrow: An Ultrastructural Comparative Study

The present study was designed to compare the ultrastructure of early endothelial progenitor cells (EPCs) derived from rabbit peripheral blood (PB-EPCs) and bone marrow (BM-EPCs). After the cells had been isolated and cultivated up to passage 3, microphotographs obtained from transmission electron microscope were evaluated from qualitative and quantitative (unbiased stereological approaches) points of view. Our results revealed that both cell populations displayed almost identical ultrastructural characteristics represented by abundant cellular organelles dispersed in the cytoplasm. Moreover, the presence of very occasionally occurring mature endothelial-specific Weibel–Palade bodies (WPBs) confirmed their endothelial lineage origin. The more advanced stage of their differentiation was also demonstrated by the relatively low nucleus/cytoplasm (N/C) ratios (0.41 ± 0.19 in PB-EPCs; 0.37 ± 0.25 in BM-EPCs). Between PB-EPCs and BM-EPCs, no differences in proportions of cells occupied by nucleus (28.13 ± 8.97 versus 25.10 ± 11.48%), mitochondria (3.71 ± 1.33 versus 4.23 ± 1.00%), and lipid droplets (0.65 ± 1.01 versus 0.36 ± 0.40%), as well as in estimations of the organelles surface densities were found. The data provide the first quantitative evaluation of the organelles of interest in PB-EPCs and BM-EPCs, and they can serve as a research framework for understanding cellular function.