RESUMEN
Long-term research into radiation exposure significantly expanded following World War II, driven by the increasing number of individuals falling ill after the detonation of two atomic bombs in Japan. Consequently, researchers intensified their efforts to investigate radiation's effects using animal models and to study disease models that emerged post-catastrophe. As a result, several parameters have been established as essential in these models, encompassing radiation doses, regimens involving single or multiple irradiations, the injection site for transplantation, and the quantity of cells to be injected. Nonetheless, researchers have observed numerous side effects in irradiated animals, prompting the development of scoring systems to monitor these animals' well-being. The aim of this review is to delve into the historical context of using animals in radiation research and explore the ethical considerations related to animal welfare, which has become an increasingly relevant topic in recent years. These concerns have prompted research groups to adopt measures aimed at reducing animal suffering. Consequently, for animal welfare, the implementation of a scoring system for clinical and behavioral monitoring is essential. This represents one of the primary challenges and hurdles in radiation studies. It is concluded that implementing standardized criteria across all institutions is aimed at ensuring result reproducibility and fostering collaboration within the scientific community.
RESUMEN
Hematopoiesis is the process by which blood cells are generated. During embryonic development, these cells migrate through different organs until they reach the bone marrow, their definitive place in adulthood. Around E10.5, the fetal liver starts budding from the gut, where first hematopoietic cells arrive and expand. Hematopoietic cell migration occurs through cytokine stimulation, receptor expression, and glycosylation patterns on the cell surface. In addition, carbohydrates can modulate different cell activation states. For this reason, we aimed to characterize and quantify fetal megakaryocytic cells in mouse fetal liver according to their glycan residues at different gestational ages through lectins. Mouse fetuses between E11.5 and E18.5 were formalin-fixed and, paraffin-embedded, for immunofluorescence analysis using confocal microscopy. The results showed that the following sugar residues were expressed in proliferating and differentiating megakaryocytes in the fetal liver at different gestational ages: α-mannose, α-glucose, galactose, GlcNAc, and two types of complex oligosaccharides. Megakaryocytes also showed three proliferation waves during liver development at E12.5, E14.5, and E18.5. Additionally, the lectins that exhibited high and specific pattern intensities at liver capsules and vessels were shown to be a less time-consuming and robust alternative alternative to conventional antibodies for displaying liver structures such as capsules and vessels, as well as for megakaryocyte differentiation in the fetal liver.