Biomedical subjects

Ewa Kopczyńska

Publications and source records attributed to Ewa Kopczyńska.

6 recordsLinked to original sources

PubMed2006

[BRAF gene mutation in thyroid cancer].

Mutations of genes coding effectors of signaling pathway RET/PTC-RAS-RAF-MEK-ERK, involved in cell growth and proliferation, are important in papillary thyroid cancer development. To earlier discovered mutations of RAS and RET/PTC genes, BRAF gene mutation has been recently added. Mutation of BRAF gene appears in various types of carcinomas, but most frequently in malignant melanomas (66%) and papillary thyroid cancer (average 44%). The BRAF gene protein product belongs to the serine-threonine kinase family and to the RAF proteins subfamily, among which it is the strongest activator of MAP kinases cascade. The most frequently mutation of BRAF gene is thymine to adenine transversion at nucleotide position 1796 (T1796A). This point mutation causes valine to glutamic acid substitution at residue 599 (V599E), that results in constitutive and oncogenic activation of BRAF kinase. The relation between mutations of BRAF, RAS and RET/PTC genes has not been found, although they together exist in two thirds of papillary thyroid cancers. BRAF(TI796A) oncogene appears in papillary thyroid cancer, whereas it has not been found in follicular thyroid cancer and benign thyroid adenomas. For this reason mutated BRAF gene could be specific molecular marker, with relatively high sensitivity in diagnostics of papillary thyroid cancer. In addition, BRAF gene has been demonstrated as a novel prognostic biomarker, which correlates with unfavorable clinicopathological factors, such as extrathyroidal invasion and distant metastasis.

Carcinoma, Papillary↗

PubMed2004

[Parameters of lipid peroxidation and low density lipoprotein (LDL) oxidation in the course of hyperthyroidism].

The aim of this study was to evaluate the influence of hyperthyroidism on lipid peroxidation and oxidative modification of low density lipoprotein (LDL). Twenty patients with hyperthyroidism due to Graves' disease or toxic multinodular goitre and 17 healthy subjects as the control group were investigated. Lipid peroxidation was measured by the serum level of malondialdehyde and 4-hydroxynonenal (MDA+4-HNE) whereas the oxidative modification of LDL was determined by measuring the serum levels of antibodies against oxidized LDL (anti-oxLDL). Ratios, which were evaluated as proportions of lipid peroxidation products level or anti-oxLDL level to the LDL-cholesterol level (LDL-C) were also determined: MDA+4-HNE/LDL-C and anti-oxLDL/LDL-C. The patients with hyperthyroidism displayed a significant elevation of the MDA+4-HNE/LDL-C ratio. The level of anti-oxLDL and anti-oxLD/LDL-C ratio were positively correlated with FT4 level and inversely correlated with HDL-cholesterol. These data suggest that the intensification of lipid peroxidation and oxidative modification of plasma lipoprotein is affected by changes in the level of thyroid hormones.

Adult↗

PubMed2002

[The level of 8-iso-prostaglandin F2 alpha, 4-hydroxynonenal and malondialdehyde in alcohol dependent men during combined therapy].

The aim of the study was the estimation of intensity of lipid peroxidation in alcohol dependent male patients after three months of therapy with naltrexone or tianeptine and the next three months follow-up. 61 males with clinical diagnosis of alcohol dependence (ICD-10) have been examined. The investigated parameters have been determined in blood serum, the 8-iso-prostaglandin F2 alpha by means of immunoenzymatic assay (ELISA) and malondialdehyde with 4-hydroxynonenal by means of colorimetric method. In alcohol dependent men before pharmacotherapy the mean concentration of 8-iso-PGF2 alpha and [MDA + 4-HNE] was higher than the reference interval. Both, after three months of applied drugs and the next three months follow-up, the concentration of studied parameters decreased considerably. The above results show intensification of lipid peroxidation in alcohol abusers and advantageous influence of abstinence from alcohol and treatment of naltrexone or tianeptine on free-radical changes of lipids as well.

Adult↗

PubMedDate not supplied

[The concentrations of homocysteine, folic acid and vitamin B12 in alcohol dependent male patients].

UNLABELLED: Metabolism of homocysteine (sulphur-containing amino acid) is accomplished in the remethylation cycle where vitamin B12 and folic acid are essential coenzymes. Markedly elevated homocysteine concentrations have been observed in patients with nutritional deficiencies of vitamin B12 and folate. Hyperhomocysteinemia in alcohol abusers may result from malnutrition and disorder of intestine absorption. AIM: The aim of the study was the estimation of homocysteine, folic acid and vitamin B12 concentrations in alcohol dependent male patients. METHOD: 71 males with a clinical diagnosis of alcohol dependence (ICD-10) have been examined. The investigated parameters have been determined in the blood serum, the homocysteine by means of immunochemical method, vitamin B12 and folic acid by means of immunoenzymatic assay. RESULTS: Serum homocysteine concentration was significantly higher and serum folic acid concentration was lower in alcohol dependent men than in controls. Mean concentrations of folic acid and vitamin B12 were significantly lower in patients with hyperhomocysteinemia than in men with normal homocysteine concentration. The highest correlation was indeed noticed between folate deficiency and the intensity of hyperhomocysteinemia. CONCLUSIONS: The development of hyperhomocysteinemia is associated with alcohol dependence that is also a probable cause of folate and vitamin B12 deficiency.

Adult↗

PubMedDate not supplied

Oxidative stress markers during a course of hyperthyroidism.

INTRODUCTION: Previous studies have shown the presence of oxidative stress in hyperthyroid patients. The aim of this study was to evaluate the influence of hyperthyroidism on lipid peroxidation, plasma lipoprotein oxidation and antioxidant status. We have estimated the clinical utility of the biochemical parameters analysed as markers of oxidative stress in hyperthyroidism. MATERIAL AND METHODS: Twenty five patients with overt hyperthyroidism because of Graves' disease or toxic multinodular goitre and 20 healthy subjects were included in the study. Lipid peroxidation was evaluated by measurement of peroxides and malondialdehyde with 4-hydroxynonenal (MDA + 4-HNE) concentrations. Autoantibodies against oxidised LDL (anti-oxLDL) were assayed as a marker of lipoprotein oxidation. Changes in the antioxidant defence system were estimated by measurement of total antioxidant status in serum (TAS) and erythrocyte superoxide dismutase activity (SOD). RESULTS: A significant increase in serum concentration of peroxides and MDA + 4-HNE was observed in patients with hyperthyroidism. However, no difference was found in anti-oxLDL concentration and antioxidant status parameters (TAS, SOD) between the control group and the patient group. CONCLUSIONS: Our results indicate an intensification of the oxidative processes caused by an excess of thyroid hormones, which is not accompanied by a response from the antioxidant system. Elevated concentrations of lipid peroxidation products in serum, both peroxides and malondialdehyde with 4-hydroxynonenal, may be useful as markers of oxidative stress during the course of hyperthyroidism.

Adult↗

PubMedDate not supplied

Mebeverine influences sodium ion transport in the distal colon.

The study was performed to check if the well-known intestinal spasmolytic effect of mebeverine is paralleled by any changes in intestinal transepithelial currents. The transepithelial potential difference related to ionic currents of the isolated rabbit distal colon wall was measured by means of Ussing's technique under control conditions and after gentle mechanical stimulation of intestinal epithelial surface by a flux from peristaltic pump and with and without of mebeverine in stimulation fluid. The transient hyperpolarization after mechanical stimulation was diminished after addition of mebeverine to the stimulation fluid when chloride transport was inhibited by bumetanide (BUME) but in the presence of amiloride (AMI), a sodium ion transport inhibitor, the drug did not influence the reaction. It was inferred that mebeverine was able to modulate transepithelial sodium ion transport and in this way to modify interaction between colonic wall and its contents during intestinal passage.

Animals↗