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J Wrońska

Publications and source records attributed to J Wrońska.

At least 19 recordsLinked to original sources

The extra-weak chemiluminescence generated during oxidation of some tetracycline antibiotics. 1. Autoxidation.

Chemiluminescence (CL) appearing during autoxidation of tetracycline (TC) antibiotics has been studied. The CL spectrum consists of four emission bands with maxima at 520, 585, 640 and 700 nm. The bands at 585, 640 and 700 nm are similar to those observed for singlet molecular oxygen (1O2). The effect of 1O2 quenchers and free radical reaction inhibitors on the light emission is also reported. The data support the concept that, during the autoxidation of TCs, cytotoxic oxygen species such as HO., O2.-, H2O2 and 1O2 are formed.

Chlortetracycline

The extra-weak chemiluminescence generated during oxidation of some tetracycline antibiotics. II. Peroxidation.

This study was undertaken to establish the mechanism of chemiluminescence during the oxidation reaction of tetracycline antibiotics in the presence of molecular oxygen and H2O2. The spectral distribution of chemiluminescence and fluorescence and the quantum yields of chemiluminescence were measured. The chemiluminescence spectrum measured with cut-off filters revealed one broad blue-green band and bands with maxima at 580, 640 and 700 nm. The bands at 580, 640 and 700 nm were similar to those observed for singlet molecular oxygen. The effect of superoxide radical, hydroxyl radical inhibitors, singlet oxygen quenchers and D2O as solvent on the light emission was also studied. The formation of singlet oxygen during the oxidation of the investigated tetracyclines was also checked using the spectrophotometric method based on the bleaching of p-nitrosodimethylaniline. A mechanism for the reactions generating electronically excited compounds is proposed.

Free Radicals

Megakaryocytic leukaemia. A case of unusual outcome.

In a 33-year-old woman with thrombocytosis, megakaryocytic hyperplasia in bone marrow, presence of megakaryocytes in peripheral blood and megakaryocyte-containing infiltrations in the liver, excellent result of Busulphan treatment (1 year full remission after Busulphan withdrawal) is reported. The authors suggest the diagnosis of megakaryocytic leukaemia.

Adult

[Pollen].

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Humans