Biomedical subjects

Hanna Czeczot

Publications and source records attributed to Hanna Czeczot.

11 recordsLinked to original sources

PubMed2006

Glutathione and GSH-dependent enzymes in patients with liver cirrhosis and hepatocellular carcinoma.

We investigated glutathione level, activities of selenium independent GSH peroxidase, selenium dependent GSH peroxidase, GSH S-transferase, GSH reductase and the rate of lipid peroxidation expressed as the level of malondialdehyde in liver tissues obtained from patients diagnosed with cirrhosis or hepatocellular carcinoma. GSH level was found to be lower in malignant tissues compared to adjacent normal tissues and it was higher in cancer than in cirrhotic tissue. Non-Se-GSH-Px activity was lower in cancer tissue compared with adjacent normal liver or cirrhotic tissue, while Se-GSH-Px activity in cancer was found to be similar to its activity in cirrhotic tissue and lower compared to control tissue. An increase in GST activity was observed in cirrhotic tissue compared with cancer tissue, whereas the GST activity in cancer was lower than in adjacent normal tissue. The activity of GSH-R was similar in cirrhotic and cancer tissues, but higher in cancer tissue compared to control liver tissue. An increased level of MDA was found in cancer tissue in comparison with control tissue, besides its level was higher in cancer tissue than in cirrhotic tissue. Our results show that the antioxidant system of cirrhosis and hepatocellular carcinoma is severely impaired. This is associated with changes of glutathione level and activities of GSH-dependent enzymes in liver tissue. GSH and enzymes cooperating with it are important factors in the process of liver diseases development.

Adult↗

PubMed2006

[Catalase: structure, properties, functions].

Catalase (EC 1.11.1.6) is an enzyme which is present mainly in the peroxisomes of mammalian cells. It is a tetrameric enzyme consisting of four identical, tetrahedrally arranged subunits of 60 kDa, each containing in its active center a heme group and NADPH. Catalase has two enzymatic activities depending on the concentration of H2O2. If the concentration of H2O2 is high, catalase acts catalytically, i.e. removes H2O2 by forming H2O and O2 (catalatic reaction). However, at a low concentration of H2O2 and in the presence of a suitable hydrogen donor, e.g. ethanol, methanol, phenol, and others, catalase acts peroxidically, removing H2O2, but oxidizing its substrate (peroxidatic reaction). The review article presents current knowledge about the structure, properties, and functions of catalase in living organisms.

Animals↗

PubMed2005

[Role of L-carnitine in metabolism, nutrition and therapy].

The review article presents the biosynthesis, metabolism, sources, levels, and general functions of L-carnitine, a naturally occurring compound widely distributed in the body. It is synthesized in the liver, kidney, and brain and carriers long-chain fatty acids into the mitochondria for beta-oxidation and energy production. L-carnitine plays an important role in the translocation of acetyl moieties from the mitochondria to the cytoplasm for acetylcholine synthesis in neurones. Other roles--include removal of excess acyl groups, peroxisomal fatty-acid oxidation, and antioxidant activity.

Acetylcholine↗

PubMed2005

[Antioxidant status of patients with primary colorectal cancer and liver metastases of colorectal cancer].

In the present work we examined selected parameters of antioxidant status in patients with primary colorectal cancer and liver metastasis of colorectal cancer. Total antioxidant status (TAS), activity of superoxide dismutase (SOD) and catalase (CAT) were examined in colorectal primary cancer, liver metastasis of colorectal cancer and in blood serum of patients before and after surgery. It was found that patients have disordered function of the the antioxidant system. This is demonstrated by decreased TAS and changes in the activity of SOD and CAT, both in tumor tissue and blood serum.

Adenocarcinoma↗

PubMed2005

[Antioxidant barrier in patients with gastric cancer--preliminary study].

UNLABELLED: Gastric carcinoma is one of the most common malignancies of causes of cancer death world-wide, although its incidence and mortality and decreasing, particularly in developed countries. One of the many factors in its etiopathogenesis are free oxygen radicals and their derivatives, excess of which comes from disturbances of enzymatic and nonenzymatic mechanisms of antioxidant barrier. The aim of this study was the evaluation activities of antioxidant enzymes: superoxide dismutase (CuZnSOD, MnSOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione transferase (GST), glutathione reductase (GSH-R) as well as measurement of glutathione (GSH) and malondialdehyde (MDA) levels both in tissues (cancer and healthy) and in blood serum obtained from patients with gastric cancer. RESULTS: MnSOD and glutathione dependent enzymes (GSH-Px, GST, GSH-R) activities in gastric cancer were found to be higher than those in healthy stomach tissues. In pre- and postoperative blood serum from patients with gastric cancer was observed increase of CAT and GST as well as decrease of CuZnSOD and GSH-Px compared with the blood serum from healthy blood donors (control group). In preoperative blood serum from patients with gastric cancer GSH-R activity was lower than in control serum, whereas in postoperative serum it was higher compared with serum of the control group. Reduced GSH level was found to be lower in gastric cancer than this in healthy stomach tissue, adjacent to the cancer. Its level was also lower in pre- and postoperative blood serum of patients with gastric cancer compared with level in control serum. MDA concentration was found to be much higher in gastric cancer than this in healthy stomach tissue, whereas weren't significant differences between level of MDA in pre- and postoperative blood serum. CONCLUSION: Our results showed that functioning of antioxidant barrier of organism is severely impaired in patients with gastric cancer.

Aged↗

PubMed2004

[Extracellular superoxide dismutase (EC-SOD)--structure, properties and functions].

EC-SOD catalyzes the dismutation of superoxide radical to hydrogen peroxide and oxygen in the interstitial spaces of tissues and in extracellular fluids (plasma, lymph, and synovial fluid). It eliminates superoxide radicals from the cell environment and prevents the formation of reactive oxygen species and their derivatives. EC-SOD is a secretory, tetrameric glycoprotein containing copper and zinc, with a high affinity to certain glycosaminoglycans, such as heparin and heparan sulfate. It plays an important role in maintaining vascular tone, lung function, and the metabolism of NO, and in the pathology of such diseases as atherosclerosis, diabetes, and arthritis. This paper describes EC-SOD structure, function in tissues, and possibilities of therapy with application of this enzyme.

Animals↗

PubMed2004

[Arginine--metabolism and functions in the human organism].

L-arginine plays important roles in the metabolism of an organism. It is the precursor for the synthesis of proteins and other molecules of great biological importance, including nitric oxide, ornithine, polyamines, agmatine, proline, glutamate, creatine, dimethylarginine, and urea. For young organisms arginine is an essential amino acid for optimal growth and development, and must therefore be provided in the diet. For adults, arginine is a conditionally essential amino acid, especially in such conditions as trauma, burn injury, small-bowel resection, and renal failure. L-arginine administration improves cardiovascular, pulmonary, immune, and digestive functions and protect against the early stages of cancerogenesis.

Adult↗

PubMed2004

[Usefulness of postoperative assay of arginase activity in blood serum of women after breast cancer resection].

The usefulness of arginase test was evaluated in follow-up of patients after breast cancer resection. The arginase activity was measured in blood serum of 970 patients from January 1996 to December 2000. The arginase activity above the normal value was detected in serum of 539 (55.6%) women. Only 197 (20%) patients demonstrated metastases and recurrence (true positive), 342 (35%) patients were disease free. The normal value of arginase activity was found in blood serum of 431 (44.4%) patients, 360 (36%) of them showed complete remission, whereas 71 (8%) demonstrated recurrence or metastases (false negative). Sensitivity of arginase test in post-surgery diagnostics of breast cancer was 73%. Measuring of arginase activity in blood serum of patients after breast cancer resection may be useful as an additional test confirming the disease dissemination.

Adult↗

PubMed2003

[Evaluation of antioxidant status in patients with primary hepatocellular carcinoma].

The aim of this work was to evaluate the efficiency of the antioxidant system in patients with primary hepatocellular carcinoma. Total antioxidant status (TAS), superdoxide dismutase (SOD) and catalase (CAT) activity was examined in liver primary cancers and in blood serum of patients before and after surgery. In comparison with healthy liver, very low activity of TAS was observed in liver cirrhosis and in primary cancer. High activity of TAS in the blood serum of patients before and after surgery was comparable with TAS activity in blood serum of healthy persons. The highest activity of SOD and CAT was observed in liver cirrhosis. The lowest activity was observed in liver primary cancer. Activity of SOD and CAT in the blood serum of patients before surgery was higher than in the blood serum of patients after surgery. The highest activity was observed in the blood serum of healthy persons. Obtained results shows, that the dysfunction of the defensive antioxidant mechanisms have characterised with not only local disturbances (in the tumour cells region), but also circuital ones (blood). Low levels of the activity of TAS, SOD and CAT in patients with primary hepatocellular carcinoma indicate to the distortion of the oxidant--antioxidant balance and the decrease of organism antioxidant system efficiency. These observations show at the participation of free radical processes in the tumour pathogenesis.

Adult↗

PubMed2002

Antitumor effects of photodynamic therapy are potentiated by 2-methoxyestradiol. A superoxide dismutase inhibitor.

Photodynamic therapy (PDT), a promising therapeutic modality for the management of solid tumors, is a two-phase treatment consisting of a photosensitizer and visible light. Increasing evidence indicates that tumor cells in regions exposed to sublethal doses of PDT can respond by rescue responses that lead to insufficient cell death. We decided to examine the role of superoxide dismutases (SODs) in the effectiveness of PDT and to investigate whether 2-methoxyestradiol (2-MeOE(2)), an inhibitor of SODs, is capable of potentiating the antitumor effects of this treatment regimen. In the initial experiment we observed that PDT induced the expression of MnSOD but not Cu,Zn-SOD in cancer cells. Pretreatment of cancer cells with a cell-permeable SOD mimetic, Mn(II)-tetrakis(4-benzoic acid)porphyrin chloride, and transient transfection with the MnSOD gene resulted in a decreased effectiveness of PDT. Inhibition of SOD activity in tumor cells by preincubation with 2-MeOE(2) produced synergistic antitumor effects when combined with PDT in 3 murine and 5 human tumor cell lines. The combination treatment was also effective in vivo producing retardation of the tumor growth and prolongation of the survival of tumor-bearing mice. We conclude that inhibition of MnSOD activity by 2-MeOE(2) is an effective treatment modality capable of potentiating the antitumor effectiveness of PDT.

2-Methoxyestradiol↗

PubMedDate not supplied

Evaluation of the mutagenic activity of phenolics from the bark of Yucca schidigera Roezl.

The mutagenic activity of yuccaols A, B, and C, trans-resveratrol and trans - 3.3',5.5'-tetrahydroxy -4'-methoxystilbene was tested by the Ames method with Salmonella typhimurium strains TA97, TA98, TA100, TA102 in the absence and presence of metabolic activation (S9 fraction). These phenolic compounds have been isolated and identified from the hark of Yucca schidigera. All of them were found to be non-toxic and non-mutagenic for testing doses in any of the S. typhimurium strains.

Animals↗