[Microcirculatory changes in chronic venous insufficiency]. / Mikrocirkulatorne promene u hronicnoj venskoj insuficijenciji.

INTRODUCTION: The venous system of lower leg can be topographically divided into two subsystems: superficial (extrafascial) and profound (subfascial). Functionally, we can divide circulation in to macrocirculation (arteries and veins) and microcirculation (arterioles, capillaries, and venules). Blood flow towards heart can be disturbed by different pathological conditions, and than chronic venous insufficiency (CVI) develops. First alterations occurs in macrocirculation, and after some period changes in microcirculation also appear. Those changes are leading to the ultimate stage in CVI--venous ulcer. RESULTS AND DISCUSSION: Previous conceptions that alterations in microcirculation in CVI are consequences of venous stasis, high pressure in capillaries and anoxic tissue are still actual. Observations that partial pressure of oxygen is higher in venous blood of lower limbs with ulceration than in limbs without ulceration lead to hypothesis that blood is passing directly from arterioles to venules over arterio-venous temperature-regulating shunts in dermis. Histological and electron-microscopic examinations certain alterations in the structure of capillaries. Raised pressure in these altered capillaries leads to exudation of plasma and fibrinogen in the interstitial space. Soluble fibrinogen is transformed to insoluble fibrin and forms fibrin cuffs. These cuffs are a barrier for normal diffusion of oxygen. Recently, it was observed that blood cells can adhere to the endothelial cells--Leukocyte trapping hypothesis. It can be explained by slower blood flow velocity and also by expression of certain endothelial and leukocyte adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1). This causes congestion of white blood cells which leads to tissue damage due to secretion of inflammatory mediators.

[Ovulation induction in women in the in vitro fertilization program]. / Indukcija ovulacije u zena ukljucenih u program vantelesne oplodnje.

In-vitro fertilization presents a method of assisted reproduction where fusion of two gametes (fertilization) occurs in laboratory conditions. In this way part of the process which normally happens in the fallopian tube is being imitated. By ovulation the number of follicles increases, thus increasing the number of oocytes, that is the number of embryos and at the same time increasing chance of pregnancy. Ovulation induction was achieved by: clomiphene citrate (CC), human menopausal gonadotropin (hMG), human chorionic gonadotropin (hCG) and luteinizing hormone-releasing hormone (LHRH). Our trial compared effects of three induction schemes: HMG-hCG; CC-hMG-hCG and LHRH-hMG-hCG. We compared the following parameters: total number of follicles, number of mature follicles (16mm with simultaneous estradiol level 350pg/ml per follicle), number of aspirated oocytes as well as the number of embryos produced by insemination of aspirated oocytes. Our examination revealed that there was no significant difference in number of follicles, aspirated and produced oocytes in patients undergoing stimulated ovulation scheme CC-hMG-hCG in regard to those with hMG-hCG schemes. In patients undergoing LHRH-hMG-hCG scheme the number of follicles was decreased and there were less oocytes, but the number of developed embryos after oocytes insemination was increased. This leads to the conclusion that in-vitro fertilization depends on quality, not only the number of oocytes obtained by LHRH agonists induction.