[Significance of MDM2 protein in the cell cycle].

The basis of oncogenesis underlies the modification of the control of the cell cycle, which leads to disturb balance between proliferation and apoptosis. The MDM2 protein suppresses the ability of p53 to activate genes responsible for repairing or apoptosis, but also promotes p53 degradation by ubiquitination. MDM2 inhibits tumor suppressor property of pRb, by releasing E2F1, which stimulates DNA synthesis in S-phase.

Adaptation of the phosphotungstate method to determine reduced and oxidized vitamin C in blood plasma.

The phosphotungstate reagent (PTR) was used for quantitative spectrophotometric determination of physiological forms of vitamin C in blood plasma. An immediate action of PTR on the first half of the tested samples allowed to determine reduced vitamin C concentrations (I) at 700 nm. 10 mM dithiothreitol added to the second half of the samples reduced oxidized vitamin C in it--hence the total amount of this vitamin was reduced with a concentration (II) determined as above (remains of dithiothreitol were removed with N-ethylmaleimide).

A study of the influence of newly synthesized acyclonucleosides and 1,2,3,4-tetrahydroisoquinoline derivatives on deoxythymidine and deoxycytidine kinase activities in human neurofibrosarcoma and ovarian cancer.

The influence of nine newly synthesized uracil acyclonucleosides, and 36 derivatives of 1,2,3,4-tetrahydroisoquinoline on the activity of enzymes catalysing dTMP and dGMP synthesis, on the content of dTTP and dGTP in acid soluble fraction and on the incorporation of [14C]dThd and [14C ]dGuo into DNA in tumour homogenates was studied. The influence of the compounds was studied in the cytosol from intraoperatively excised human tumours - neurofibrosarcoma and ovarian cancer. It was shown that dTMP and dGMP synthesis is inhibited competitively by 34.

Adaptation of the phosphotungstate method for the determination of vitamin C contents in animal and human tissues.

The usefulness of phosphotungstate reagent for vitamin C determination in tissue homogenates has been confirmed. An optimal homogenization medium was selected: 1.8 M solution of HPO3 in 1.

Antigen levels of urokinase type plasminogen activator and its inhibitors in primary breast cancer.

Primary Breast Cancer, Urokinase-Type Plasminogen Activator, Inhibitors The aim of the study was to monitor urokinase plasminogen activator antigen concentrations and its type 1 (PAI-1) and type 2 (PAI-2) inhibitors in histologically defined forms of primary breast cancer and a comparison with these antigens levels in normal tissue. Another goal was a search for a relationship/or its lack/between the occurrence of the new generation markers of neoplastic disease and a presence/or absence/of lymph node metastases. U-PA, PAI-1 and PAI-2 antigen levels were determined by ELISA tests in protein extracts of breast cancer tissues.

Pyrimidine and purine salvage deoxyribonucleoside metabolism in hepatic and renal homogenates from rats pretreated with propylthiouracil or L-thyroxine.

OBJECTIVES: In vitro activities of thymidine kinase (TK, EC 2.7.1.

Thymidine kinase and adenosine kinase activities in homogenates of thyroid lobes in hemithyroidectomized rats; effects of melatonin in vitro.

OBJECTIVES: Thymidine kinase (TK, EC 2.7.1.