Fibrinoid and intervillous spaces of the mature human placenta were morphologically and quantitatively examined in pregnant women of different ages. The aim of this research was to compare the results and to confirm if there is some quantitative difference between fibrinoid and intervillous spaces of placenta related to the age of pregnant women. The examined group of women were of age between 20 and 45 years, and they were divided into two groups: 1) pregnant women 20-35 year old; 2) pregnant women over 35 years old. The volume density and absolute volume of fibrinoid and intervillous space of placenta were stereologically examined. Volume densities of fibrinoid and intervillous space of placentas in older pregnant women compared to younger is significantly increased. Absolute volumes of fibrinoid and intervillous space of placentas in younger and older pregnant women are not significantly different.

Cystatin C is a natural inhibitor of the cysteine proteinases papain, and mammalian lysosomal cathepsins B, H, L and S. This protein is thought to serve an important physiological role as a local regulator of enzyme activity. The changes of levels of cystatin C in extracellular fluids have shown themselves having potential clinical importance. We have purified cystatin C from urine of patients with chronic renal failure by procedure using affinity chromatography on CM-papain Sepharose, gel filtration on Sephacryl S-200, and ion exchange chromatography on CM-cellulose. After isolation we obtained three inhibitory peaks (pI's from 7.8 to 9.2) which represent isoforms of the same protein. These isoforms are immunologically identical and differ in N-terminal sequence of the molecule. The form with pI 9.2 represents the intact inhibitor form, whereas the form with pI 7.8 is shortened for 8 amino-acid residues at N-terminal end. Purified cystatin C pI 9.2 was used for immunization of rabbits. Polyclonal antibodies, produced in rabbits, were isolated from rabbit sera by affinity chromatography on Protein A Sepharose. Enzyme immunoassay (ELISA) for cystatin C is developed on the basis of purified antibodies. Using ELISA test we determined amount of cystatin C in urine and serum samples of patients with chronic renal failure. The concentration of the inhibitor in the urine of these patients was approximately 100-fold more than in normal urine. In the serum from the same patients we found concentrations of cystatin C to be five times higher in comparison with the serum of healthy individuals.