The role of reactive oxygen intermediates in the pathogenesis of chronic apical periodontitis.

The level of malondialdehyde, a stable end product of lipid peroxidation induced by reactive oxygen intermediates and the activity of two potent antioxidant enzymes, superoxide dismutase and glutathione peroxidase, was investigated in tissue homogenates of 22 surgical periapical granuloma specimens. Malondialdehyde levels were significantly higher and glutathione peroxidase activity was significantly lower in periapical granuloma samples than in healthy gingival tissue homogenates, which were used as controls. The activity of superoxide dismutase was similar in periapical granuloma and in control samples.

Fibronectin in bronchoalveolar lavage fluid and plasma of dogs with acute inflammation of the lungs.

Bronchoalveolar inflammation, which was generated in dogs by Broncho-Vaxom instilled into the right lower lobe, was characterized first of all by an increased influx of macrophages. In this non-purulent acute-subacute inflammatory reaction, the lavage fibronectin decreased rapidly three hours after the incubation and then a marked gradual elevation was observed, which persisted throughout the whole two-week process, while plasma fibronectin concentrations were not altered significantly. Changes in the levels of lavage fibronectin may be an important sign for the control of the inflammatory reaction activity in the lungs.

Decreased sensitivity of cytostatic drugs in glucocorticoid receptor-free acute myeloid leukaemia cells. Clinical and experimental observations.

Preliminary clinical observations have suggested that low cellular glucocorticoid receptor (GR) levels might have been connected with multidrug resistance in children with acute myeloblastic leukaemia (AML). To test this possibility, we have developed glucocorticoid resistant subclones of two recently established human myeloid leukaemic cell lines. The cause of glucocorticoid resistance was GR negativity in these subclones.

Erythrocyte damage in newborn babies caused by hyperbilirubinaemia and hypoxia.

Erythrocyte damage of newborn babies suffering from hyperbilirubinaemia and hypoxia was compared with a control group. In the cases of serum bilirubin level higher than physiological icterus lipid peroxidation of erythrocytes decreased probably due to the antioxidant effect of bilirubin. Moreover, an increase in potassium and protein outflow from patients' red blood cells was observed indicating a membrane damage both in hyperbilirubinaemic and hypoxic groups.

Effects of prostaglandin E2 on the newborn respiratory system.

To test the hypothesis that prostaglandin (PG) E2 is a respiratory depressant in the newborn lamb, 12 chronically catheterized, unanesthetized lambs (age 2 to 6 days) were infused with progressively increasing doses of PGE2 (0.1, 0.5, 1.