The influence of surgical treatment and red blood cell transfusion on changes in antioxidative and immune system parameters in colorectal cancer patients.

OBJECTIVE. To determine the effect of surgical treatment and red blood cell transfusion on the parameters of antioxidative and immune systems in patients with early and advanced stage colorectal cancer. MATERIAL AND METHODS. A total of 65 patients with colorectal cancer were included in the study. Three blood serum samples of each patient were tested comparing presurgical and postsurgical periods of 7 and 14 days. Malondialdehyde and total glutathione levels, activity of catalase and glutathione S-transferase were determined spectrophotometrically. The concentration of cytokines TGF-beta1 and TNF-alpha were determined by ELISA. RESULTS. Malondialdehyde and glutathione levels decreased in surgically treated patients with cancer of both stages while catalase activity decreased in patients with stage III cancer. Cytokine levels did not change after surgery. A decrease in malondialdehyde concentration was observed in the transfused patients with early stage cancer comparing postsurgical periods. Catalase activity was increased after surgery in patients with early stage cancer but was decreased during postsurgical periods in patients with advanced stage cancer. Cytokine levels increased at postsurgical periods in transfused patients with stage III cancer. Correlation between catalase activity and TNF-alpha level and between glutathione S-transferase activity and TGF-beta1 level was determined postsurgically in transfused patients with early stage cancer. CONCLUSIONS. Postsurgical period affected antioxidative system of patients with cancer of both stages while level of cytokines showed no differences. Transfusion determined distinct dynamics of antioxidative parameters due to cancer stage. Elevated cytokine levels in transfused patients with advanced stage cancer showed that the status of immune system was exacerbated. Antioxidative and immune systems were depressed in these patients. Correlation between antioxidative system parameters and cytokines in transfused patients of early stage cancer showed a relationship between two protective systems of the organism against malignant process.

Characterization and physicochemical properties of a lipase from Pseudomonas mendocina 3121-1.

The lipase from Pseudomonas mendocina 3121-1 was found to be homogeneous with a molecular mass of 30 kDa by SDS/PAGE. It is composed of two identical subunits. A molecular mass of 62 kDa was determined by gel chromatography on a Toyopearl HW-55F column. Some physicochemical properties of the lipase were investigated using p-nitrophenyl butyrate (p-NPB), Tween 80 solution and Sigma olive-oil emulsion as substrates. The optimum temperature was determined to be 52 degrees C with p-NPB, in the range 50-60 degrees C with Tween 80 and in the range 50-65 degrees C with olive-oil emulsion. The optimum pH was determined to be in the pH range 7.2-7.5, both with Tween and the emulsion, but was unusually alkaline (pH 9.5) with p-NPB. The enzyme was activated for p-NPB hydrolysis by thermal treatment up to 60 min at 60 degrees C, pH 7.0-8.2, but was rapidly inactivated at 70-80 degrees C and at pH 7.0. The lipase was shown to be more thermolabile at 60 degrees C with respect to other two substrates. Using the emulsified substrate, no activity was obtained after preincubating the enzyme for 30 min at 70 degrees C. The enzyme was found to be pH-tolerant when stored at 20 degrees C, pH 6.3-10.3 (100 mM Briton-Robson buffer) as the half-life (t(1/2)) was more than 240 h when p-NPB was used as the substrate. By contrast, the pH-stability range was more narrow (pH 8.0-10.5) with olive-oil emulsion. The effect of various metal ions and EDTA depended on the nature of the substrate.