Orientador: Débora Cristina Damasceno / Resumo: Early embryos recovered from diabetic rats show increased number of blastomeres undergoing apoptosis and decreased total number of blastomeres, suggesting impaired litter size and newborn weight. This might increase the chances of metabolic disorders in adulthood of these animals. Since diabetes-induced hyperglycemia impairs the redox balance, the aim was to evaluate the embryonic oxidative stress status before the implantation in order to identify whether there are differences in levels of oxidative stress in early embryos from diabetic dams. Thus, we hypothesized the decreased cell number found in early embryos recovered from diabetic rats is due to the low embryonic ability to maintain their own redox balance. Our study shows that rats with streptozotocin-induced mild and severe diabetes present impaired redox status in early pregnancy. This maternal unbalance directly influences the embryonic redox status, reflecting the increased reactive oxygen species in the morula stage. We also showed that regardless of hyperglycemic level the embryos trigger defense mechanisms involved in the excessive free radical scavenging as an attempt to survive. Nevertheless, the success of this defense mechanism seems to depend on maternal hyperglycemia, highlighting the importance of the programmed pregnancy as well as appropriate medical care starting in early stages of human diabetic pregnancy. / Doutor

Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum are causative agents of Lyme disease and human granulocytic anaplasmosis. Their common vector in Europe are the ticks from the genus Ixodes. In our work, we focused on interaction of innate immune cells with the causative agent of Lyme diseases, that are insubstitutable in their function in the early phase of the disease. Anaplasma phagocytophilum is hard to cultivate, the only possibility is to cultivate it in cell cultures. Successful cultivation of Anaplasma phagocytophilum acquired from patients in our geographic area is crucial for following experiments and for diagnostics too. In our experiments, we used validated cell cultures of HL-60 cells, canine monocytes DH82 and murine monocytes P388D1. During our studies of interaction of the causative agent of Lyme diseases with cells, we used two strains of different species Borrelia. Borrelia garinii M192 and Borrelia burgdorferi sensu stricto B31. These strains vary in virulence. The strain M192 is virulent, but the strain B31 lost its virulence by passages. We specialised in study of morphological changes using light microscopy (observation of dyed and fixed preparates and observation in dark field), eventually by transmision electron microscopy. During our experiments, we concluded that HL-60...

17 beta-Hydroxy-11 beta(4-dimethylaminophenyl)-17 alpha-(1-propynyl)estra-4, 9-dien-3-one (RU486) inhibited the in vitro development of different stages of mouse preimplantation embryos under study. Two-celled embryos, morulae, and early blastocysts were obtained from B6D2F1 mice. The embryos were grown in Ham F-10 nutrient mixture (with glutamine) supplemented with sodium bicarbonate (2.1 g/L), calcium lactate (282 mg/L), and bovine serum albumin (fraction V, 3 mg/mL) at 37 degrees C in a humidified incubator supplied with 5% CO2 in air. RU486 was added to the culture medium at concentrations of 1, 5, 10, and 20 micrograms/mL. Culture medium with 0.05% ethanol served as the control. In vitro growth of embryos was assessed by the following criteria: (i) two-celled stage embryo development to blastocyst stage after 72 h, (ii) morula stage grown to blastocyst stage after 24 h, and (iii) early blastocyst stage development to hatching blastocyst after 12 h, in culture. RU486 inhibited the in vitro development of two-celled embryos, morulae, and early blastocysts at concentrations of 5, 10, and 20 micrograms/mL culture medium (p less than 0.001). The inhibitory effect of RU486 at these concentrations on the development of all the stages of embryos under study was irreversible. However, RU486 did not affect embryo development at 1 microgram/mL culture medium. The study indicates the direct adverse effect of RU486 at 5 micrograms/mL and higher concentrations in culture medium on the development of mouse preimplantation embryos in vitro, and it encourages its further investigation as a postcoital contraceptive in animal models and humans.