The incidence of venous thrombosis in the general population is low, approximately 3 per 10 000 women per year among women in reproductive age. Despite the low incidence, use of hormonal... Show moreThe incidence of venous thrombosis in the general population is low, approximately 3 per 10 000 women per year among women in reproductive age. Despite the low incidence, use of hormonal contraceptives frequently causes venous thrombosis since millions of women worldwide use hormonal contraceptives. This use is associated with a two- to eight-fold increased risk of venous thrombosis, dependent on the type and dose of the contents of the hormonal contraceptive. The aim of this thesis was to study the risk of venous thrombosis during use of different hormonal contraceptives, focusing on the pathogenesis, the evaluation of a marker to estimate the risk of venous thrombosis, and the assessment of effectiveness, side effects including the risk of venous thrombosis and acceptability of a new hormonal contraceptive. Show less
This thesis describes the investigation of the transcriptional regulation of the gene for anticoagulant plasma Protein S, PROS1. Protein S is a cofactor for Protein C in the Protein C anticoagulant... Show moreThis thesis describes the investigation of the transcriptional regulation of the gene for anticoagulant plasma Protein S, PROS1. Protein S is a cofactor for Protein C in the Protein C anticoagulant pathway. The coagulation cascade is negatively regulated by this pathway through inactivation of activated clotting factors V and VIII. Protein S deficiency is associated with an increased risk for the development of deep venous thrombotic disease and the deficiency can either be hereditary or acquired. The presented research was mainly aimed at resolving several basic scientific issues regarding the regulation of transcription of PROS1. In Chapter 2 we identified 3 transcription start sites through which transcription is mainly driven. In chapters 3 and 4 we investigated which transcription factors are involved in PROS1 transcription. We found an interaction of several transcription factors with the Protein S gene promoter and showed that constitutive transcriptional activity is mainly directed by transcription factor Sp1. Chapter 5 describes the regulation of Protein S levels by inflammatory mediator interleukin 6. The effect of interleukin 6 on Protein S levels was shown to be mediated though a direct interaction of transcription factor STAT3 with the Protein S gene promoter. In Chapter 6 an alternative PROS1 transcript is described. The protein that is generated from this transcript in vitro was shown not to be excreted from the cell but instead retained in the cell. Finally, our findings are discussed in Chapter 7. Show less
