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[en] This study was intended to investigate the effect of valproate (VPA) and oxcarbazepine (OXC) on embryo implantation in terms of extracellular matrix protein distribution. Thirty female rats (Wistar albino) were assigned to three groups of 10 animals each. Group 1 was administered two doses of saline solution, group 2, two doses of VPA at 300 mg/kg/day and group 3, two doses of OXC at 100 mg/kg/day, for a period of 3 months. Female rats with vaginal plugs mated with males for one night were placed into separate cages. Day of mating was taken as day 0, and implantation areas were obtained with rats being sacrificed on the morning of day 7. Immunohistochemical staining and electron microscopic protocols were then applied. At electron microscopic evaluation, extraembryonic endoderm and ectoderm layers could not be distinguished in semi-thin sections in the VPA group, while they were partially differentiated in the OXC group. At immunohistochemical staining, laminin was observed in the primary embryonic endoderm cell visceral and parietal layers, the uterine luminal epithelial cells and the secondary decidual zone in the control group. In the VPA group, it was weakly expressed in some embryo trophoectoderm cells and uterine luminal epithelial cells and moderately in some decidual cells. In the OXC group, it was moderately expressed in some trophoectoderm and decidual cells. Collagen IV was localized in the ectoplacental cone cells and secondary decidual zone and weak in the luminal epithelial cells in the control group. In the VPA and OXC groups, collagen IV was negative in all embryonic and maternal structures in the VPA and OXC groups. Vimentin was moderately expressed in the luminal epithelium and strongly expressed in the primary decidual zone and ectoplacental cone cells in the control group. In the VPA group, it was negative in the embryo trophoectoderm, decidual and uterine luminal epithelial cells, while in the OXC group it was moderately localized in the ectoplacental cone cells. The use of VPA and OXC has a negative effect on the expression of extracellular matrix proteins that play a key role in embryo implantation in young rats. This may lead to pregnancies ending in failure.
[en] Four main aspects of embryo technology are dealt with in this paper. The first analyses the reasons for the poor selection of recipients for embryo transfer, the second relates to inaccurate evaluation of embryos at least under tropical conditions, the third proposes alternative methods to evaluate embryos for selection and freezing, and the fourth analyses the feasibility of establishing this technique as a biotechnology approach for improving production in small community tropical farms. (author)
[en] LINE-1 (Long Interspersed Nuclear Elements) and HERVs (Human Endogenous Retroviruses) are two families of autonomously replicating retrotransposons that together account for about 28% of the human genome. Genes harbored within LINE-1 and HERV retrotransposons, particularly those encoding the reverse transcriptase (RT) enzyme, are generally expressed at low levels in differentiated cells, but their expression is upregulated in transformed cells and embryonic tissues. Here we discuss a recently discovered RT-dependent mechanism that operates in tumorigenesis and reversibly modulates phenotypic and functional variations associated with tumor progression. Downregulation of active LINE-1 elements drastically reduces the tumorigenic potential of cancer cells, paralleled by reduced proliferation and increased differentiation. Pharmacological RT inhibitors (e.g., nevirapine and efavirenz) exert similar effects on tumorigenic cell lines, both in culture and in animal models. The HERV-K family play a distinct complementary role in stress-dependent transition of melanoma cells from an adherent, non-aggressive, to a non-adherent, highly malignant, growth phenotype. In synthesis, the retrotransposon-encoded RT is increasingly emerging as a key regulator of tumor progression and a promising target in a novel anti-cancer therapy
[en] Nanoparticle (NP) surface coatings are known to influence the toxicity of engineered nanomaterials. This work examines the effect of glycine functionalization on silica NPs and investigates changes in viability and developmental defects in the organs of zebrafish embryos upon exposure. Silica NPs and glycine-functionalized silica NPs are synthesized and characterized. Exposure of zebrafish embryos to glycine-silica NPs affects the mortality percentage in a similar manner to soluble glycine. Developmental defects are observed in embryos exposed to soluble glycine, glycine-silica NPs, or silica NPs in comparison with the unexposed embryos. The damage is localized in the brain, heart, and liver of zebrafish embryos. These observations suggest a complex mechanism of toxicity, with glycine maintaining its toxic activity even when covalently bound on silica surface. Our results illustrate that surface modification of non-lethal particles can create different toxicity outcomes in the organs of exposed zebrafish embryos. - Highlights: • Modification of silica nanoparticles with glycine impacts the toxicity profile of silica. • Free and bound glycine induces developmental abnormalities in embryonic zebrafish. • Developmental defects in brain, liver and cardiovascular system are assessed.
[en] The recent development of ultrasound technology has resulted in remarkable progress in the visualization of early embryos and fetuses and in the development of sonoembryology. With the use of three-dimensional ultrasound, structural developments in the first 12 weeks of gestation can be assessed more objectively and reliably. The new technology allowed for the evolution of embryology from postmortem studies to the in vivo environment. The purpose of this review to illustrate the potential of sonography in the study of structural and functional early human development
[en] Committee 2 of the International Commission on Radiological Protection has the responsibility for calculating radiation doses from intakes of radionuclides for all age groups in the population. This includes the development of models for calculating doses to the embryo and fetus following intakes of radionuclides by the mother. In the development of models for the fetus, human data have been used as far as is possible. Where human data are not available, a generic modelling approach based principally on information from experimental animals on relative concentrations of radionuclides in fetal and maternal tissues has been used. These models are being applied to calculate doses to the offspring for acute and chronic intakes of radionuclides by the mother, both before conception and at various times during gestation. The development of both biokinetic and dosimetric models are reviewed and the results of preliminary dose calculations presented. (author)
[en] Multiple evidence demonstrate a role for serotonin and its transporter SERT in heart valve development and disease. By utilizing a Cre/loxP system driven by SERT gene expression, we recently demonstrated a regionally restricted distribution of SERT-expressing cells in developing mouse heart. In order to characterize the cell types exhibiting SERT expression within the mouse heart valves at early developmental stages, in this study we performed immunohistochemistry for Islet1 (Isl1) and connexin-43 (Cx-43) on heart sections from SERTCre/+;ROSA26R embryos previously stained with X-gal. We observed the co-localization of LacZ staining with Isl1 labelling in the outflow tract, the right ventricle and the conal region of E11.5 mouse heart. Cx-43 labelled cells co-localized with LacZ stained cells in the forming atrioventricular valves. These results demonstrate the cardiomyocyte phenotype of SERT-expressing cells in heart valves of the developing mouse heart, thus suggesting an active role of SERT in early heart valve development.