MOLECULAR RELATIONSHIP BETWEEN H-2 AND ML ANTIGENS ON LEUKAEMIA L-1210/v CELLS*

The molecular relationship between H-2 antigens and mammary leukaemia (ML) antigen at the surface of leukaemic L-1210/v cells was studied by the ‘lyso-strip’ method. Molecules carrying the private specificities of the H-2^d haplotype are independent entities in the membrane of the L-1210/v leukaemic cells and are not linked to molecules carrying the ‘Ml’ antigen.     

Choroidal neovascularization in children--prevalence, diagnostics and treatment

Choroidal neovascularization (CNV) belongs to the rare retinal disorders in children. Authors present 3 cases of CNV, which were diagnosed in patients between 12-15 years of age (2 females and 1 male). Complete ophthalmological examination including fluorescein angiography, indocyanine angiography and optical coherence tomography were performed in all cases. Laboratory tests to exclude the systemic diseases were also done. CNV in young people maybe a result of high myopia, angioid streaks, ocular histoplasmosis, trauma or it could be idiopathic. In our series, we found idiopathic CNV in 2 eyes and 1 CNV after traumatic choroidal break. Stabilization of visual acuity was achieved after argon laser treatment in 2 cases.     

Amphetamine-induced effects on neuropeptide Y in the rat brain

Repeated (+)-amphetamine sulfate (AMPH) administration (5 mg/kg sc twice daily for 6 days and once on day 7) markedly and reversibly decreased (until 96 h after the final dose) neuropeptide Y-like immunoreactivity (NPY-LI) in the rat striatum (caudate-putamen) and nucleus accumbens, and had no effect on NPY-LI in the hippocampus. No significant alterations were detected in the hybridization signal of NPY mRNA4 and 24 h after the end of AMPH treatment. A single dose of AMPH (5 mg/kg sc) administered to rats 4 and 24 h prior to sacrifice had no effect on NPY-LI in the brain structures studied. Moreover, AMPH injected 8 days after the last dose of repeated AMPH administration did not change NPY-LI up to 72 h. The minimal dose of haloperidol, the strong mixed dopaminergic D2/D1 receptor antagonist, (0.75 mg/kg injected ip 30 min before each of the multiple AMPH administrations) that was sufficient to completely block stereotypy and hyperlocomotion elicited by multiple AMPH administrations enhanced the AMPH-induced decrease in the striatal and accumbens NPY-LI. Our results suggest that NPY neurons in the striatum, nucleus accumbens and hippocampus are not directly involved in the acute behavioral response to AMPH (stereotypy and hyperlocomotion) as well as in the initiation and expression of AMPH-induced behavioral sensitization.     

Protective effect of Aquilegia vulgaris (L.) on APAP-induced oxidative stress in rats

Rats pretreated with acetaminophen (N-acetyl-p-aminophenol, APAP) (600 mg/kg b.w., p.o.) were administered with ethanol and ethyl acetate extracts as well as with isocytisoside (100 mg/kg b.w., p.o.) obtained from Aquilegia vulgaris (L.) (Ranunculaceae) herb. The substances tested decreased enzymatic, non-enzymatic and uninduced microsomal lipid peroxidation (LPO) in the liver of rats treated with APAP by 18-48%. Activity of the antioxidant enzymes in the liver inhibited by APAP was increased in the majority of groups after administration of the substances tested: catalase (CAT) by 55%, glutathione peroxidase (GPx) by 50%, glutathione reductase (GR) by 35% and glutathione S-transferase (GST) by 60%. Hepatic glutathione level depleted by APAP was only slightly increased by the substances tested. The cytochrome P450 contents, and the activities of NADPH-cytochrome P450 reductase and two monooxygenases were not affected by the extracts and isocytisoside. It can be concluded that the protective ability of the substances tested in APAP-induced liver injury is mediated by amelioration of microsomal lipid peroxidation and restoring antioxidant enzymes activity. Inhibition of enzymes responsible for metabolic activation of APAP is not involved in this process.     

Evaluation of mutagenic and genotoxic activities of new derivatives of anthracyclines

The phenomenon of multidrug resistance is connected with an increased efflux of cytotoxic agents from the cells and is a serious problem in the treatment with anthracycline antibiotics. Search for new antitumor drugs from the anthracycline group are focused on the syntheris of derivatives with changes in saccharide and anthracycline parts. The genotoxic activity of selected nine new derivatives of anthracycline was evaluate basing on reference tests: micronucleus test in vitro and the Ames test. A correlation was observed between the results obtained in the Ames test and those received in the micronucleus test. In both tests, derivative WP903 demonstrated a strong genotoxic action.     

Thrombolysis and stent implantation in a child with an acute occlusion of the modified Blalock-Taussig shunt--a case report

A case of a 5-year-old boy with complex heart disease and acute occlusion of modified Blalock-Taussig shunt is presented. The patient was treated with balloon angioplasty and local infusion of recombinant tissue plasminogen activator without persistent good effect. He was successful treated with the implantation of two coronary stents into the occluded shunt.     

L-arginine supplementation prolongs exercise capacity in congestive heart failure

BACKGROUND: In congestive heart failure (CHF), endothelial dysfunction may contribute to impairment of exercise induced vasodilatation and decreased exercise capacity. We hypothesised that administration of L-arginine, a precursor of nitric oxide (NO) and postulated antioxidant, may improve endothelium-dependent vasodilatation and exercise capacity and also exert antioxidant activity. AIMS: To investigate the effect of oral supplementation with L-arginine on exercise capacity and markers of oxidative stress in patients with mild to moderate CHF. METHODS: The study had a randomised double-blind cross-over design. Twenty one patients with stable NYHA II-III CHF underwent three exercise tests: initially, after oral administration of L-arginine (9 g/day for 7 days) or placebo. Blood was sampled prior to each test for plasma lipid peroxides, reduced sulphydryl groups and leukocyte oxygen free radical production. RESULTS: We found a higher prolongation of exercise duration time after L-arginine than after placebo (99+/-106 vs 70+/-99 s, p<0.05). There were no significant differences in markers of free radical activity. CONCLUSIONS: In patients with chronic stable CHF, oral supplementation with L-arginine prolongs exercise duration which may be due to NO-induced peripheral vasodilatation. The antioxidant properties of L-arginine have not been confirmed in this ex vivo study.     

Effects of cardiopulmonary bypass on the expression of adhesive molecules in children undergoing cardiac surgery due to congenital heart disorders

BACKGROUND: Infants and small children who undergo cardiac surgery due to congenital heart disorders, are at risk of developing inflammatory complications and multi-organ failure. AIM: To assess the changes in the expression of adhesive molecules on neutrophils and in peripheral blood plasma in children undergoing cardiac surgery with or without the use of cardiopulmonary bypass (CPB). METHODS: In 18 children who underwent surgery with the use of CPB and in 7 children who underwent surgery without CPB, the expression of CD11b, CD11c and CD62L molecules on neutrophils and soluble adhesive molecules - L-selectin and ICAM-1, was assessed before, during and after cardiac surgery. RESULTS: A significant increase in the expression of CD11b on neutrophils at the time of the initiation of CPB was observed. The most pronounced decrease in the expression of CD11c was detected at the end of surgical procedure. There was also a negative correlation between L-selectin concentration measured at the end of CPB and CPB duration as well as between ICAM-1 concentration and duration of hypothermia. CONCLUSIONS: Cardiac surgery influences the expression of adhesive molecules on neutrophils and in blood plasma. These changes are more pronounced in children who undergo CPB, and depend on CPB duration as well as the use of hypothermia.