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Biomedical subjects

A Antczak

Publications and source records attributed to A Antczak.

28 records · Page 2Linked to original sources
PubMed1994

Protective effect of ambroxol against heat- and hydrogen peroxide-induced damage to lung lipids in mice.

We wanted to determine whether ambroxol, a drug which stimulates the release of surfactant by type II pneumocytes, can protect lung lipids from peroxidative damage in mice. Animals were injected intraperitoneally with ambroxol, 0.169 mmol.kg-1, or 1 ml buffer once a day for three consecutive days. Lipid peroxidation was then induced in lung homogenates either by means of heat, 50 degrees C, or H2O2, 10 mmol.l-1. The lung homogenates from ambroxol-treated animals revealed decreased lipid peroxidation in response to both stimuli. The heat- and H2O2-induced generation of conjugated dienes (a first lipid peroxidation product) in ambroxol-treated lung homogenates was 3.7 and 3.1 fold lower than in the lungs from buffer-injected mice. Ambroxol, as an inhibitor of heat- and H2O2-induced lipid peroxidation, was equipotent to and stronger than the two antioxidants, N-acetylcysteine and methionine, respectively. Ambroxol was not able to protect heart and liver lipids. These results suggest that ambroxol can sufficiently enhance the antioxidant defence in lung tissue and can act as a lung lipid antioxidant.

Acetylcysteine↗
PubMed1993

Effect of bacterial lipopolysaccharide on the content of lipid peroxidation products in lungs and other organs of mice.

The influence of lipopolysaccharide from Escherichia coli (LPS, 17 mg/kg body weight) on the lipid peroxidation process in organs of mice was studied. The content of conjugated dienes (CD), lipid peroxides (LP), malondialdehyde (MDA) (all three lipid peroxidation by-products), peroxidase (PO) activity and wet-to-dry weight ratio in lungs, heart, spleen, kidneys and liver were determined 1.5 h after intravenous injection of LPS. Animals observed at this time-point had reduced activity and decreased body temperature by about 2 degrees C, however, all analysed organs did not reveal any changes of wet-to-dry weight ratio comparing to organs from mice injected with sterile, pyrogen free 0.9% NaCl. Only extracts from heart and lungs showed significant increase in the tissue level of at least two lipid peroxidation products. The heart content of CD, MDA, and LP was about 1.5-, 1.3-, and 2.4-fold higher than in control group. In lungs CD and MDA increased 3.3- and 1.3-times but in spleen only content of LP was elevated. In these organs the suppression of PO activity was also observed. Liver and kidneys did not reveal any convincing enhancement of lipid peroxidation process and alterations of PO activity. Since free radical reactions are involved in lipid peroxidation process and inactivation of PO these results suggest that heart, lungs and spleen are the organs mostly exposed to oxidative stress during the first 1.5 h after single injection of LPS in mice.

Animals↗
PubMed1993

Ascorbic acid enhances the decrease in peroxidase activity in inflamed tissues of mice.

The aim of this study was to explore whether intraperitoneal administration of ascorbic acid (AA) at a dose of 500 mg/kg, once a day for 3 following days, affected the peroxidase (PO) activity in inflamed feet of mice. The foot inflammatory reaction induced by the carrageenan (CAR), n-formyl-methionyl-leucyl-phenylalanine (FMLP) and xanthine-xanthine oxidase was accompanied by suppression of PO activity. Administration of AA, having no effect on the degree of foot oedema, skin temperature and microscopic picture of tissue specimens significantly enhanced the decline in PO activity provoked by inflammatory agents. This activity decreased 2.0-, 1.6- and 1.9-fold (p < 0.001, p < 0.01, p < 0.05) when inflammatory response was induced with FMLP, CAR and X-XO, respectively. Also in vitro AA (50-100 micrograms/ml) inhibited PO activity of leukocyte lysate and foot extract obtained from untreated animals. In conclusion we found that AA, having no effect on inflammatory response, significantly enhanced inhibition of PO activity in inflamed tissues in mice which could be a result of direct action of AA on the enzyme molecule.

Animals↗
PubMed1993

[Cardiac arrhythmias during extracorporeal shock wave lithotripsy].

Holter monitoring was performed in 55 patients (24 women, 31 men), mean age 50.7 +/- 11.3 who underwent ECG-triggered extracorporeal shock wave lithotripsy (ESWL). Patients were divided into two groups A--30 with history of cardiac disease and B--25 control. The heart rate was significantly higher before and after ESWL in the first group. The number of premature ventricular contractions was higher during ESWL in the same group. No other cardiac complication was observed.

Adult↗
PubMed1991

Effect of ascorbic acid on hydroxyl radical generation by chemical, enzymatic and cellular systems. Importance for antioxidant prevention of pulmonary emphysema.

The ability of ascorbic acid (AA) (25 to 500 microM) to increase OH production by a chemical (Fe(2+)-EDTA-H2O2), an enzymatic (xanthine-xanthine oxidase-Fe(2+)-EDTA) and a cellular system (3.10(6) human polymorphonuclear leukocytes (PMNL) or murine peritoneal macrophages (PM) activated with 7.2 ng PMA/ml) was studied. At all concentrations used AA strongly enhanced OH generation by the chemical and the enzymatic systems. However, the maximal increase of about 14-fold was found for incomplete chemical system (10 microM Fe(2+)-20 microM EDTA) and 500 microM AA. In the case of phorbol-myristate-acetate-activated-PMNL and macrophages, the moderate increase in OH formation was only caused by low AA concentrations. At 50 microM AA, the OH formation was 112 +/- 3 and 117 +/- 4% of control, respectively. Higher AA concentrations had no influence or even decreased OH formation by phagocytes. It is suggested that administration of AA will not significantly enhance OH generation from pulmonary phagocytes and could be useful for prevention of the oxidant-mediated lung injury related to inflammation.

Animals↗
PubMed1991

Effect of ascorbic acid on killing of lymphocytes and macrophages by hydrogen peroxide.

The ability of ascorbic acid (AA) to modify the H2O2 (0.6 to 9 mM) toxic activity for human lymphocytes (PBMC) and murine peritoneal macrophages (PM) was studied in vitro. 100 microM AA added simultaneously with H2O2 to the cell medium enhanced the killing of PBMC but not of PM independently of the presence of Fe(2+)-EDTA. Similarly, preincubation of PBMC with 500 microM AA that resulted in a 2.5-fold rise in the intracellular level of AA increased their susceptibility to both H2O2 and H2O2-Fe(2+)-EDTA. On the contrary, PM preincubated with AA were more resistant to the toxic action of the H2O2-Fe(2+)-EDTA system and did not reveal any changes of the susceptibility to H2O2 alone. It is suggested that AA under certain conditions may have opposite effects on the H2O2-induced cell damage related to inflammation.

Animals↗
PubMedDate not supplied

Inhalations of 5-ALA in photodynamic diagnosis of bronchial cancer.

BACKGROUND: Photodynamic bronchoscopy (PDD) allows for early detection of bronchial cancer. Adverse effects and high costs, partly related to general application of photosensitisers, are important limitations of the method. The local application of a photosensitiser could help to minimize these problems. In this study the validity and safety of inhaled 5-ALA have been tested. METHODS: We examined 49 patients (age 59 +/- 11, cigarette consumption 36 +/- 17 pack-years) with present or past respiratory neoplasms and other with increased risk of bronchial cancer by photodynamic bronchoscopy (Storz-D-light) after inhaled 5-ALA. Biopsies were taken from the fluorescence-positive and negative foci (control). Symptoms and pre-/post-inhalation spirometry were analysed. RESULTS: The overall sensitivity was 82%, specificity 62%, positive predicted value (PPV) 45% and negative predictive value (NPV) 90%. Specificity decreased to 53% and PPV to 15% when visible tumours were excluded. PDD, when added to white light bronchoscopy increased sensitivity by 2.1% and NPV by 6%, but decreased specificity by 35.4% and PPV by 53.1%. In a group of actual or past tumours the sensitivity increased by 22% and NPV by 34%, whereas specificity decreased by 26% and PPV by 35%. In 2 cases a drop in FEV1 above 10% of pre-inhalation value was observed but no clinically relevant symptoms were reported. CONCLUSIONS: Photodynamic bronchoscopy with inhalation of 5-ALA is a relatively safe diagnostic method. The main disadvantage is high percentage of false positive results. Nevertheless, we believe, that it may be a useful adjunct to conventional diagnostic modes, especially in the detection of early lesions in patients operated due to cancer (stump control and detection of metachronous lesions) and those prepared for operation (synchronous lesions and detection of infiltration margins). However all suspected lesions must be verified by histo-pathological examination.

Administration, Inhalation↗
PubMedDate not supplied

Ascorbic acid did not alter the content of conjugated dienes and malondialdehyde in organs of mice.

The aim of this study was to explore whether ip administration of ascorbic acid (AA) in a dose of 500 mg/kg, once a day for 3 following days, affected the content of lipid peroxidation products: malondialdehyde (MDA) and conjugated dienes (CD) in organs of mice. Injection of AA caused 2.1-, 1.3- and 1.8-fold increase in the concentration of this vitamin in liver, spleen and lungs, respectively, while the content of MDA and CD in these organs did not differ from values found in animals treated with 0.9% NaCl. It suggests that in our animal model AA did not act as a prooxidant enhancing the lipid peroxidation in various tissues.

Animals↗
PubMedDate not supplied

Ambroxol inhibits endotoxin-induced lipid peroxidation in mice.

Administration of ambroxol (70 mg/kg ip) once a day for 3 days protected lung and heart lipids from lipopolysaccharide (LPS, 17 mg/kg)-induced oxidative stress in mice. Ambroxol as a lipid peroxidation inhibitor was almost as active as an equivalent dose of N-acetylcysteine (27.6 mg/kg), a well known antioxidant. The lung and heart levels of conjugated dienes in animals pretreated with ambroxol were 3.3- and 1.7-times lower (p < 0.05 and p < 0.01) than those observed in the control group which received only buffer and subsequently LPS. These results indicate that ambroxol can sufficiently inhibit the harmful process of lipid peroxidation in vivo.

Ambroxol↗